mass flow assessment

Transcription

MASS FLOW ASSESSMENT (MFA) AND ASSESSMENT OF
RECYCLING STRATEGIES FOR CATHODE RAY TUBES (CRTS)
FOR THE CAPE METROPOLITAN AREA (CMA), SOUTH AFRICA
SOUTH AFRICAN PROJECT “KNOWLEDGE PARTNERSHIPS IN E-WASTE RECYCLING”
Diploma Student:
Dominik Zumbuehl
Supervision:
Prof. Susanne Kytzia, ETH Regional Resource Management, Zurich / Switzerland
Dr. Mathias Schluep, Empa Technology and Society Lab, St.Gallen / Switzerland
October 2006
With the support of KFPE Commission for Research
Partnerships with Developing Countries
ACKNOWLEDGEMENT
I would like to express my gratitude to all those who gave me the possibility to complete this thesis.
Special thanks belong to:
… Prof. Susanne Kytzia and Dr. Mathias Schluep for the supervising and guiding during this thesis.
… Susan and Mark Dittke, the most generous hosts in Cape Town, for the unforgettable stay in
Zeekoevlei.
… Miriam Keller and Ronny Haase for their company and IT support during the thesis.
… Dr. Harro von Blottnitz, Christian Nissing and Carol Carr from the University of Cape Town
Chemical Engineering Department for their precious support.
… Gerry Newson for his efforts and the information provided for this study.
… Roland Hischier for the substantial support of the environmental impact assessment.
… Rolf Widmer and Martin Streicher-Porte. Their inputs were always highly appreciated.
… Urs Gerig, Jochen Apfel, Dudley Bradford, Juan Nomdo, Bred Scholz and Rob Packham for the
informative site visits.
… Daniel Gsponer for his maritime knowledge.
… Samsung Corning Germany.
… Peter Bornard for his precious experience.
… Paul Rooney for the proofreading of this document.
… Ray Lombard and Alan Finlay for the time spent in Johannesburg.
Moreover, to all of which contributed to this study with any information:
Alison, Inca Cape, Andrew Craig, Dirk Goris, Anthony Gracie, Tom Gloster, Saliem Haider, Jack
Heyns, Sophie Heyns, David Hula, Trevor Karshagen, Kuehne & Nagel, Marina Lancaster, John
Mensing, Peter Novella and Michael Tatana.
Finally yet importantly, I would like to thank my friends and family for their patience and Franziska
for her Love.
ABSTRACT
Cathode ray tubes (CRTs) are a major problem for further recycling in South Africa. At this stage,
an economically feasible and environmentally sound recycling process is not available. CRTs are
currently dumped or landfilled.
The aim of this study is to provide background information for the future management of CRT
screens in South Africa. Thus, a mass flow assessment (MFA) of cathode ray tube computer monitors and TVs for the Cape Metropolitan Area (CMA) based on the year 2005 was carried out. In
addition, time series were calculated to forecast future figures of obsolete CRT devices. In a second step, local and best available recycling alternatives for the recycling of CRT glass were specified and assessed towards their sustainability using the Multi Attribute Utility Theory (MAUT) methodology.
The results of the MFA showed a significant consumer stock growth of both CRT monitors and
TVs. Only little CRT devices are disposed of at landfill sites. The obsolescence will increase until
2020 for CRT computer monitors and for CRT TVs until 2020 to 2030. It is expected that in the year
2007 some 400 tons of CRT monitors and 600 tons of CRT TVs will become obsolete.
The dismantling of CRT monitors and TVs is already established and economically feasible. Only
the CRT cannot be recycled at this stage and is therefore landfilled. For the future recycling, local
brick manufactures and the building industry is able to use the CRT glass in their processes. Neither the assessed, local metal smelters nor glass manufacturers were prepared to use CRT glass
in their processes. From the best available technologies, the use of CRT glass in the production of
new CRTs and the use of CRT glass in the copper/lead smelting process were included in recycling scenarios. Together with the local option, eight scenarios were assessed using the MAUT
methodology. A set of attributes was defined to evaluate the scenarios including economical, environmental and social attributes.
The study shows that the manufacturing of new CRTs from recycled CRT glass is the best option in
terms of sustainability. As second best option the lead recovery from CRT glass was identified.
TABLE OF CONTENTS
1 INTRODUCTION........................................................................................................................ 10
1.1
1.2
1.3
1.4
1.5
What is e-waste?................................................................................................................ 10
Global e-waste development ............................................................................................. 11
E-waste management and regulation ................................................................................ 12
Management of e-waste in South Africa ............................................................................ 13
Objective of this study........................................................................................................ 14
2 METHODS ................................................................................................................................. 16
2.1 Mass Flow Assessment ..................................................................................................... 16
2.1.1 Mass flows of CRT monitors and TVs in the studied region.................................. 16
2.1.2 Time series of CRT computer monitors................................................................. 16
2.1.3 Time series of TV sets in the studied region ......................................................... 17
2.2 Scenario analysis ............................................................................................................... 18
2.3 Multi-Attribute Utility Theory (MAUT) ................................................................................. 19
2.3.1 Attributes used in the MAUT assessment ............................................................. 19
2.3.2 Normalisation of attributes ..................................................................................... 23
2.3.3 Weighting of attributes ........................................................................................... 23
2.4 Robustness Analysis.......................................................................................................... 24
2.4.1 Error analysis and error propagation ..................................................................... 24
2.4.2 Determination of the upper and lower bounds of the MAUT utilities ..................... 25
3 MASS FLOW ASSESSMENT ................................................................................................... 27
3.1 System Definition ............................................................................................................... 27
3.1.1 Selection of case study region............................................................................... 27
3.1.2 Players in the case study region............................................................................ 28
3.1.3 Manufacturers, Distributors and Import Statistics.................................................. 28
3.1.4 Second hand suppliers .......................................................................................... 29
3.1.5 Consumer .............................................................................................................. 30
3.1.6 TV refurbishers ...................................................................................................... 30
3.1.7 Collectors............................................................................................................... 30
3.1.8 Recyclers ............................................................................................................... 31
3.1.9 Landfilling............................................................................................................... 32
3.2 CRT computer monitor and TV composition...................................................................... 34
3.3 Mass flows of CRT computer monitors in the CMA in the year 2005 ................................ 35
3.4 Time series of CRT computer monitors ............................................................................. 37
3.5 Mass flows of CRT TVs in the CMA in the year 2005........................................................ 39
3.6 Time series of CRT TVs..................................................................................................... 40
4 SCENARIO ANALYSIS ............................................................................................................. 43
4.1 CRT Recycling technologies .............................................................................................. 43
4.1.1 Pre-processing – stripping of CRT monitors and TVs ........................................... 44
4.1.2 Crushing and sorting techniques ........................................................................... 45
4.1.3 Separating techniques ........................................................................................... 47
4.1.4 CRT glass in new CRTs ........................................................................................ 50
4.1.5 CRT glass in smelting processes .......................................................................... 50
4.1.6 CRT glass in bricks ................................................................................................ 53
4.1.7 CRT glass in concrete rubble ................................................................................ 53
4.1.8 CRT glass in foam glass........................................................................................ 54
4.1.9 CRT glass in container glass ................................................................................. 54
4.1.10 CRT glass in flat glass ........................................................................................... 54
4.2 Definition of the CRT recycling scenarios .......................................................................... 55
4.3 Application of the MAUT .................................................................................................... 57
4.3.1 Adjustment of the attributes ................................................................................... 57
4.3.2 Scenario 0 – Landfill .............................................................................................. 58
4.3.3 Scenario 1 - Lead mine.......................................................................................... 60
4.3.4 Scenario 2 - Concrete Rubble ............................................................................... 62
4.3.5 Scenario 3 - Recycled crushed aggregate (RCA) bricks ....................................... 64
4.3.6 Scenario 3a - Concrete bricks ............................................................................... 66
4.3.7 Scenario 3b - Andela CRT crushing device........................................................... 67
4.3.8 Scenario 4 - CRT manufacturing ........................................................................... 68
4.3.9 Scenario 5 - Lead recovery.................................................................................... 71
4.4 Summary of results and discussion ................................................................................... 74
4.4.1 Comparison of the unweighted and weighted utilities ........................................... 74
4.4.2 Weighted utilities.................................................................................................... 75
4.4.3 Comparison of the attributes.................................................................................. 76
4.4.4 Recycling fees........................................................................................................ 79
5 CONCLUSIONS......................................................................................................................... 81
6 OUTLOOK.................................................................................................................................. 83
REFERENCES ................................................................................................................................ 84
APPENDICES ................................................................................................................................. 92
LIST OF FIGURES
Figure 1:
Top scoring countries in PC growth rates and penetration rate .................. 12
Figure 2:
Example of two processes involved in the processing of CRT screens...... 22
Figure 3:
General procedure for the calculation of Eco-indicators.. ........................... 22
Figure 6:
System picture with the players involved..................................................... 28
Figure 7:
Smart City refurbishment centre in Cape Town. ......................................... 30
Figure 8:
Worker is dismantling a computer at Footprints. ......................................... 31
Figure 9:
The first container designed to dispose of e-waste in the CMA at the
Wynberg Drop-off Centre............................................................................. 31
Figure 10:
CRT monitor stockpiles and stripping at Desco Electronic Recyclers......... 32
Figure 11:
Impressions from the Coastal Park municipal solid waste landfill site and
from the Athlone refuse transfer station ...................................................... 33
Figure 13:
Mass flows of computer monitors in the CMA, 2005 ................................... 35
Figure 14:
Time series of CRT monitors in the CMA. ................................................... 38
Figure 15:
Mass flow assessment of CRT TV sets in the CMA, 2005.......................... 39
Figure 16:
Yearly inputs of colour TVs into the CMA.................................................... 40
Figure 17:
Time series of the input function of CRT TVs and their obsolescence ....... 41
Figure 18:
Possible pathways for the recycling of CRT appliances.............................. 43
Figure 19:
Impressions from the CRT glass recycling at SwissGlas. ........................... 46
Figure 20:
Process illustration at RUAG Component Inc.............................................. 47
Figure 23:
Lining of the Vissershok landfill site in the year 2000.................................. 58
Figure 24:
Current baseline recycling scenario of TVs and computer Monitors........... 59
Figure 25:
Scenario 0: landfilling of CRTs at Vissershok landfill site............................ 59
Figure 26:
Scenario 1: Storage of CRTs in the Black Mountain lead mine .................. 61
Figure 27:
Scenario 2: Use of CRTs in concrete rubble manufacturing ....................... 63
Figure 28:
Scenario 3: Use of CRT glass in the manufacturing of recycled crushed
aggregate (RCA) bricks ............................................................................... 65
Figure 29:
Scenario 4: CRT manufacturing in Germany .............................................. 69
Figure 30:
Scenario 5: lead recovery at Metallo-Chimique........................................... 71
Figure 31:
Unweighted MAUT results and the results with the stakeholders’ weight... 74
Figure 32:
Comparison of the weighted and unweighted MAUT utilities. ..................... 75
Figure 33:
Impact 2002+. .............................................................................................. 78
LIST OF TABLES
Table 1:
Attributes applied in the MAUT assessment................................................ 20
Table 2:
Transfer scale for the weighting in the MAUT assessment ......................... 24
Table 3:
Allocation of relative error to the input parameters used for the MAUT
assessment.................................................................................................. 24
Table 4:
Composition of a CRT computer monitor according to literature data ........ 34
Table 5:
Comparison of several separation technologies towards costs, capacity
and quality.................................................................................................... 49
Table 6:
Technical and economical feasibility of the CRT recycling technologies .... 55
Table 7:
Overview of all scenarios described in this section and used for the
MAUT assessment....................................................................................... 56
Table 8:
Adjustment of the set of attributes ............................................................... 57
Table 9:
Overview of the MAUT results from scenario 0 ........................................... 60
Table 10
Table 11:
Table 12:
Table 13:
Results of the environmental assessment of scenario 3a ........................... 66
Table 14:
Overview of the MAUT results from scenario 3b ......................................... 68
Table 15:
Table 16:
Table 17:
Derivation of the weight percentage of the luminescent screen coating
used in CRTs ............................................................................................... 100
Table 18:
Average composition of a CRT.................................................................... 101
APPENDICES
Appendix 1: Glossary ............................................................................................................ 92
Appendix 2: Definitions of e-waste........................................................................................ 93
Appendix 3: Swiss State Secretariat for Economic Affairs’ global e-waste program ............ 94
Appendix 4: Import statistics from DTI and SARS ................................................................ 95
Appendix 5: MFA computer monitors: specifications of the flows......................................... 96
Appendix 6: Questionnaire sent to the distributors of CRT monitors and TVs in the CMA... 97
Appendix 7: Penetrations rates of TVs and personal computers in South Africa ................. 98
Appendix 8: Detailed listing of WDI and SARS figures ......................................................... 98
Appendix 9: Relationship of weight, diameter and volume of currently (2006) sold TVs...... 99
Appendix 10: Toxicity and legislation of hazardous components in the CRT ....................... 100
Appendix 11: Furnace batch composition and material savings........................................... 108
Appendix 12: Constants used for the MAUT assessment of the recycling scenarios........... 109
Appendix 13: Supporting calculations use din the MAUT assessment................................. 110
Appendix 14: Environmental gain and loss assessment of all scenarios; ............................ 115
Appendix 15: MAUT; questionnaire for the weighting of attributes ....................................... 116
Appendix 16: Results of the weighting of the attributes ........................................................ 117
Appendix 17: Offer for the shipping of a 40 feet container from Kuehne + Nagel ................ 118
Appendix 18: MAUT attribute vs. scenario matrix. ................................................................ 119
Appendix 19: MAUT values unweighted and weighted used in Figure 32............................ 120
INTRODUCTION
1
INTRODUCTION
The Swiss State Secretariat for Economic Affairs (seco) has commissioned the Swiss Federal
Laboratories for Materials Testing and Research (EMPA) to conduct a study. The main objective of
the study was to propose a global program to improve existing e-waste management systems. This
led to seco's global e-waste program "Knowledge Partnerships in e-Waste Recycling" which is
described in a more detailed manner in Appendix 3.
In the context of the "Knowledge Partnerships in e-Waste Recycling" program EMPA commissioned two studies carried out at the Swiss Federal Institute of Technology (ETH) which address
two different aspects of the broad issue of e-waste in two different countries. One study conducted
in India addresses the informal precious metal recovery process from e-waste. This study focuses
on a particular issue of the management e-waste in South Africa. The main objectives of the study
are listed in section 1.5. In the following sections, the e-waste issue is introduced. The meaning of
e-waste as well as an explanation of its global relevance is explained.
1.1
What is e-waste?
In common speech in industrialized countries, “e-waste” is regarded as being an electrical or electronic device, which has no further (economic) value to the user. However when an electrical or
electronic device becomes useless for the primary user it can still have a value for the next holders.
The owner can sell it and then it follows a chain where it is reused, recovered or finally disposed of.
Consequently, “e-waste” is a very difficult term to define. At this stage there is no generally accepted definition for the term “e-waste (Widmer et al., 2005). Attempts to define the term have been
performed by several authorities and authors. A selection of definitions and the different categories
of e-waste is defined by the EU WEEE Directive (The European Parliament and the Council of the
European Union, 2003) and are listed in Appendix 2. In this study e-waste is referred to as "Any
appliance using an electric power supply that has reached its end-of-life” as it is defined by the
Organisation for Economic Co-operation and Development OECD (2001). E-waste is a controversial issue discussed on a global scale and features several risks and opportunities.
One opportunity of e-waste is that the appropriate recycling is “…clearly advantageous from an
environmental perspective.” as proved in a study conducted by Hischier, et. al (2006). The authors
compared the environmental impacts of a scenario of e-waste recycling to the baseline scenario of
incineration of all e-waste and primary production of raw materials. Another prospect of e-waste is
its content of valuable raw materials (also strategic materials 1) including many rare metals. They
can be recovered with different existing techniques. Thus e-waste recycling has becomes a lucrative business.
The risky part of e-waste is that it contains over 1’000 different substances and metals. Many of
these substances and metals are toxic. According to Widmer et al. (2005) hazards such as lead,
mercury, arsenic, cadmium, selenium, hexavalent chromium and flame retardants in casings and
circuit boards are present. The printed circuit boards (PCB) (= printed wiring boards, PWB) contain
polychlorinated and polybrominated biphenyls that create dioxin-like emissions when burned. All
these hazardous substances can threaten human health and the environment unless they are dis-
1 Material for which the quantity required for essential civilian and military uses exceeds the reasonably secure domestic
and foreign supplies and for which acceptable substitutes are not available within a reasonable period of time (American
Metal Market, 1985)
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INTRODUCTION
posed of properly (Li et al., 2006). Corresponding to (Silicon Valley Toxics Coalition (SVTC), 2002)
“About 70% of heavy metals (including mercury and cadmium) found in landfills come from electronic discards”. According to a report of the European Commission 40 percent of the lead found in
landfills derives from consumer electronics (Commission of the European Communities, 2000).
Thus e-waste is a double-edged sword. On the one hand, valuable materials can be recovered
economically whilst natural resources can be saved. On the other hand, the risks of hazardous
substances being released in the environment when not processed properly can cause serious
damage to the human health and the environment.
1.2
Global e-waste development
Because of rapid technological progress and the decreasing lifespan of the single electronic devices, e-waste is growing rapidly. In 2004, more than 180 million personal computers (PCs) were
sold worldwide. In the same year, an estimated 100 million obsolete PCs entered waste streams
(Widmer et al., 2005). Worldwide e-waste growth can only be estimated and is in the range of 20 to
50 million tons per year. The main volume is produced in North America followed from Europe and
Asia (Siemers and Vest, 1999). According to “The Economist” (Berlin Economist Office, 2005) ewaste is one of the fastest growing waste fractions. It accounts for some 8% of all municipal waste
in Europe.
At present e-waste is mainly generated by industrialised countries, which already have a high
amount of electrical and electronic equipment. It is assumed that some of the e-waste generated in
industrialised countries ends up in developing countries such as India or Africa. The British Protection Agency released a report in May 2005 admitting that a large amount of e-waste had been exported illegally from the UK (Agarwal, 2005). In Lagos (Nigeria), 400’000 used computers arrive at
the port each month. 25 % - 75% of them are out of order and have to be disposed (Puckett et al.,
2002). According to Iles (2004) the US exported up to 10.2 millions obsolete computers (or around
50-80% of all PCs sent for recycling in the US) to Asia in 2002. The reason for these exports might
be the less strict environmental standards in developing countries and lower disposal costs. For
example disposing a computer in the US can cost up to $ 20, while an Indian trader pays between
$ 10 and $ 15 for the disused computer (Agarwal, 2005).
In the future, however a large quantity of e-waste will be produced by the developing countries
themselves. Figure 1 shows the growth of personal computers in the different countries. It reveals
the enormous PC growth per capita in developing countries.
Due to the above developments, countries like India, China and Africa will face an increasing
amount of e-waste originating from inland and through illegal exports in the future. To deal with the
fast-growing, valuable and hazardous waste load, this waste stream has to be managed properly
and has to be controlled by putting up guidelines and regulations.
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INTRODUCTION
Figure 1: Top scoring countries in PC growth rates (left) and penetration rate (right) (Schwarzer et al., 2005)
1.3
E-waste management and regulation
E-waste management
The idea of an e-waste management is to set up a local or nationwide system where e-waste finds
the way back within the country of origin from the consumer to the recycling facility rather than to
the municipal solid waste stream or to the landfill. Several organisations, i.e. the “Secretariat of
Basel convention” or the “StEP-initiative” try to develop global standards of such management systems. A central goal of the Basel convention is environmentally sound management (ESM). “ESM
means taking all practical steps to minimize the generation of hazardous wastes and strictly controlling its storage, transport, treatment, reuse, recycling, recovery and final disposal, the purpose
of which is to protect human health and the environment” (Secretariat of the Basel Convention,
2006). One of the five major tasks of StEP is to enhance infrastructures, systems and technologies
to realize sustainable e-waste recycling (StEP, 2005). Different possibilities to finance recycling are
available, i.e. introducing an Advanced Recycling Fee (ARF) or a payment at the time of the disposal.
In Switzerland, a properly functioning e-waste management has been realized. It is the first country
who has established a nation-wide take-back system with state of the art recycling technologies,
financed by an ARF. This system was established in the early 90s based on the initiative of the
electronic industry itself. The current system is now controlled by two producer responsibility organisations (P.R.O): SWICO Recycling Guarantee and SENS. SWICO comprises more than 400
providers in the ICT/CE segment and has become one of the most important industry associations
in Switzerland.
Even if a country or region organises its e-waste management system within the industry, legislations have to be set up to define the general framework. From the economical point of view the
valuable parts of e-waste, i.e. precious metals are from particular interest. Therefore these parts
will be recovered steered by the market demand. To prevent that recyclers take only these parts
(“cherry-picking”) and dump the invaluable and often toxic parts, regulations have to be implemented. Legislations therefore generally focus on the decontamination of e-waste.
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INTRODUCTION
European e-waste legislation
In 2003 the European Community introduced WEEE (Waste Electrical or Electronic Equipment)
Directive 2002/96/EC (The European Parliament and the Council of the European Union, 2003).
This regulation is currently being transposed in the EU member states. Main objectives and regulations are the prevention of WEEE, reuse, recycling and other forms of recovery. The reduction of
the disposal of WEEE as unsorted municipal waste is also an objective.
Most of the costs for the current disposal and the environmental sound recycling of e-waste are
generated due to its hazardous substances. To reduce the hazardous content of future e-waste the
RoHS (Restrictions of Hazardous Substances) directive (The European Parliament and the Council
of the European Union, 2003) bans several hazardous substances in the manufacturing of EEE.
Materials like lead, mercury or polybrominated biphenyls (PBB) have to be substituted by safer
materials if technologically and economically feasible. The appendix of the RoHS directive specifies
some exceptions for the use of mercury mainly in fluorescent lamps, lead in CRTs or solder, cadmium and hexavalent chromium and lead containing devices are defined. The regulation has become effective by July 2006.
International legislation
Despite of the implementation of the above-mentioned legislations there are still concerns about
the treatment of e-waste in non EC- or OECD countries. As mentioned before the driving forces for
the recyclers to send e-waste to developing regions are low labour costs and partly the absence of
environmental regulations. This makes it economically interesting to send e-waste to non OECDcountries such as China, India or Nigeria.
To prevent the developed world to use the developing world as a dumping ground a multilateral
environmental agreement known as the Basel Convention was implemented and entered into force
in 1992. Basel Convention is an UN convention and its principle idea is to set up a framework for
controlling the “transboundary” movements of hazardous wastes. In 1995, the “Ban Amendment”
which is incorporated in the Basel Convention had been introduced. “The Amendment calls for
prohibiting exports of hazardous wastes (for any purpose) from countries listed in a proposed new
annex to the Convention (Annex VII - Parties that are members of the EU, OECD and Liechtenstein) to all other Parties to the Convention.” The Amendment has not yet entered into force (Secretariat of the Basel Convention, 2006).
The implementation of the BC and related agreements are coordinated by the “Secretariat of the
Basel Convention”, located in Geneva, Switzerland and administered by UNEP. It also provides
assistance and guidelines on legal and technical issues, gathers statistical data and conducts training on the proper management of hazardous waste (Secretariat of the Basel Convention, 2006).
1.4
Management of e-waste in South Africa
This section’s content is partly retrieved from the “eWaste Guide” (EMPA, 2004). This website
serves as a knowledge base on e-waste recycling with a focus on the needs of developing or transition countries. It says that:
“South Africa consists of a middle-income emerging market with an abundant supply of natural
resources, well-developed financial, legal, communications, energy, and transport sectors; a stock
exchange that ranks among the 10 largest in the world and a modern infrastructure supporting an
efficient distribution of goods to major urban centres throughout the region. However, growth has
not been strong enough to lower South Africa's high unemployment rate. Daunting economic problems remain from the apartheid era, especially poverty and lack of economic empowerment among
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INTRODUCTION
the disadvantaged groups. High crime and HIV/AIDS infection rates also deter investment. South
African economic policy is fiscally conservative, but pragmatic, focusing on targeting inflation and
liberalizing trade as means to increase job growth and household income.”
and:
“The rate in which e-waste is generated is rapidly increasing. There is well-established waste legislation and municipal waste management systems in place, as well as a strong recycling industry.
63% of cans, 51.9% of paper, 25.5% of metal and 28% of paper is currently recovered” (Ray
Lombard, National Recycling Forum, 2002).
Very little is known about the e-waste generated and imported to South Africa. It was estimated
that 1.2 to 1.5 million computers enter the South African market each year. About 70% of the country’s e-waste is thought to be in storage – most of this held by the government. This percentage
represents about 10 - 20 thousand tons of e-waste, which is expected to double in 10 years time to
30 - 40 thousand tons (Lombard et al., 2004).
Policies and Strategies:
South Africa has signed and ratified the Basel Convention. The National Environmental Management Act (NEMA, 1998) is intended to provide the principal framework for integrating good environmental management into all development activities. NEMA makes provision for waste management through the principles that refer to avoidance or minimisation and remediation of pollution,
including waste reduction, re-use, recycling and proper waste disposal.
The “White Paper on Integrated Pollution and Waste Management for South Africa” intends to encourage the waste management department to change towards recycling, reuse or total reduction
of waste (DEAT, 1998). In 2001, the government at national, provincial and local level met at the
first National Waste Summit in Pietersburg. They adopted “The Polokwane Declaration on Waste
Management” (Government of South Africa, 2001). It was recognized that: “… waste management
is a priority for all South Africans, and the need for urgent action to reduce, reuse, and recycle
waste in order to protect the environment.” The ambitious goal of the declaration is to reduce waste
generation and disposal by 50% and 25% respectively by 2012 plus develop a plan for “zero
waste” by 2022. The Hazardous Substances Act (PRepublic of South Africa, 1973) provides the
regulations to control the management of hazardous substances and the disposal of hazardous
waste.
These policies, strategies and legislations should boost the future waste management and particularly the management of e-waste in South Africa. However, at present in South Africa there is no
specific legislation regarding the handling or recycling of e-waste. The recycling of e-waste is currently carried out by recycling companies and scrap dealers and thus in absence of a regulatory
framework only the valuable parts are currently recovered.
1.5
Objective of this study
The "Green e-Waste Channel" was established in Cape Town in 2005 by the scientific partnership
e-Waste Recycling Switzerland - South Africa. The "Green e-Waste Channel" is presenting a replicable concept that is equally appealing for suppliers, consumers, recyclers, governmental agencies and public interest groups. The goal is to establish a secure disposal system for e-waste with
drop-off points, take-back centres and pick-up services. Manufacturer and recycling branches
should work together so that the benefit is optimised, hence avoiding the need for waste fees as
much as possible.
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INTRODUCTION
Experience with the first service providers unveiled that cathode ray tube (CRT) screens are a major problem for further recycling. Due to their lead content existing glass recyclers cannot include
CRT screens in their process and an environmental sound and financial feasible recycling process
is not available in South Africa so far. Thus, CRT screens becoming obsolete have to be disposed
of in landfill sites. Due to limited landfill volumes, high disposal costs, environmental concerns as
well as economic losses due to a high content of valuable materials such as iron, copper, lead,
plastics and PWBs (printed wiring boards) in CRT devices, brings around a high interest in alternative disposal methods focusing on more sustainable reuse and recycling scenarios for CRT
screens. Aims of this study:
a)
Carrying out a Mass Flow Assessment (MFA) of CRT computer monitors and TVs within
the studied region.
b)
The investigation of possible future recycling scenarios considering the existing recycling
practice and the Best Available Technology (BAT).
c)
The assessment of these recycling scenarios towards their sustainability.
This study will be carried out in the Cape Metropolitan Area (CMA) that is described in section
3.1.1.
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METHODS
2
METHODS
In this section, the methods used in this study are described. First, a dynamic mass flow assessment (MFA) of the selected region was applied to derive the mass flows and the time series of obsolete CRT monitors and TVs. In a second step, a scenario analysis was carried out. This comprises the analysis of the current CRT recycling scenario (baseline scenario) within the studied
region and the analysis of different recycling alternatives including local and South African industry
as well as best available technology overseas. The methodology of this assessment is described in
section 2.2. Once the scenarios were defined, they were assessed towards their sustainability using the Multi Attribute Utility Theory (MAUT) described in section 2.3. This resulted in a ranking of
the utilities of each scenario included in this assessment. The ranking was further assessed towards its robustness including error analysis and error propagation described in 2.4.
2.1
Mass Flow Assessment
Mass flow assessment (MFA) or material flow analysis is a systematic assessment of the flows and
stocks of materials within a system defined in space and time. It connects the sources, the pathways, and the intermediate and final sinks of a material. Because of the law on “conservation of
matter”, the results of an MFA can be controlled by a simple material balance comparing all inputs,
stocks, and outputs of a process. It is this distinct characteristic of MFA that makes such method
attractive as a decision-support tool in resource management, waste management, and environmental management (Brunner et al., 2004).
MFA determines, describes and analyzes the metabolism of industries, regions, or materials. In
MFA, the metabolism of a system stands for the transfer, storage, and transformation of materials
within the system and the exchange of materials within its environment (Brunner and Rechberger,
2004). The methodology for the MFA was originally developed for industrialized countries, and was
recently applied in developing countries by Binder (Binder et al., 2001; Streicher-Porte, 2006) for
the early recognition of the environmental impacts from human activities.
2.1.1
Mass flows of CRT monitors and TVs in the studied region
The system boundary for the MFA in this study is the area of the Cape Metropolitan Area shown in
Figure 5 (section 3.1.1). The material studied in the MFA comprises CRT computer monitors and
CRT TVs within the CMA. A stakeholder analysis was first carried out to define the processes and
direction of the flows of the materials. The processes considered in the MFA consist of import, distribution and consumption as well as the collecting, recycling and disposal processes.
The system picture with the actors involved in the MFA and the system borders (= system boundaries) is presented in section 3.1.2. All figures for the flows of computer monitors and TVs were assessed by interviewing the involved players and by questionnaires as well as by site visits. Since
most of the data were based on estimates (except sales figures) an upper and a lower limit was
calculated for most of the flows.
2.1.2
Time series of CRT computer monitors
MFA is usually carried out on a yearly base and therefore it is not possible to show the development of stock changes or obsolescence of items over time. To assess the future obsolescence of
CRT monitors and TVs in the CMA, a time series was calculated using sales figures, import statistics and penetrations rates for computer monitors from the World Bank’s World Development Indicator (WDI, 2003). In addition, forecasts of sales figures for CRT computer monitors were included
Dominik Zumbuehl
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in the model. According to (Streicher-Porte, 2006) the following formula was used to calculate the
obsolete CRT screens at a certain point in time:
O(t x ) = Stot (t x −L )
(1)
Whereas
O(tx) = obsolete items at time x (in tons)
Stot = sales (in tons)
L = average lifespan of an item
In the case of the computer monitors time series, overall sales figures from the distributors would
have been necessary. Since not all the distributors provided sales figures, the sales figures of the
distributors were multiplied by the reciprocal value of the corresponding market share to derive the
total sales figures mathematically demonstrated in the following equation:
Stot = Si ×
1
mi
(2)
Stot = total sales
Si
= sales figures market player i
mi
= market share of player
2.1.3
Time series of TV sets in the studied region
A different approach was used to carry out the time series for TVs in the MFA. Penetration rates
from the year 1975 to 2001 (SABC’s first broadcasting was in 1976) and custom statistics from
1992 up to 2005 were available (see Appendix 7 and Appendix 8). These figures were used to
derive the overall input of TVs in the CMA.
For the years 1975 to 1991 data from the World Bank World Development Indicator (WDI, 2003)
was taken to calculate
iWDI(t) = fCMA × (
P(t) × pSA(t) - P(t-1) × pSA(t-1)
1000
)
(3)
And from 1992 up to 2005 the custom statistics were used to calculate:
iC(t) = fCMA × C(t)
(4)
Then the overall input was calculated using:
Itot =
1991
∑
iWDI(t) +
t=1975
2005
∑
ic(t)
(5)
t=1992
Whereas
iWDI = Input per year (derived from the World Bank World Development Indicator)
fCMA = Transfer factor from national to CMA figures (see section 3.1.3)
P(t) = Penetration rate TVs in use per 1000 capita (WDI)
p(t) = South African population (WDI)
Itot
= Overall input of TVs into CMA from 1975 to 2005
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C(t) = Custom statistics (=import figures)
Due to very unsteady yearly inputs, (see Figure 16) the figures were transformed into a triangular
slope starting in 1975 with an input of 0 and peaking in 2005. The area under this slope has to be
the same as Itot. The peak input in 2005 was calculated using:
ip =
2 ×Itot
Δt
ip
= Peak input in the year 2005
Itot
= Overall input of TVs into CMA from 1975 to 2005
Δt = Time span from 1975 to 2005
With ip the time series for the input function was calculated and is shown in Figure 17. With this
transformed, linear function the obsolete series was computed. According to (Streicher-Porte,
2006) the time series for the obsolete items were calculated using:
O(t x ) = i(t x -L )
2.2
O
= Obsolete items [tons]
I
= Input per year [tons]
L
= Average lifespan of an item [years]
(6)
Scenario analysis
This section describes the procedures how the CRT recycling scenarios were defined, described
and assessed.
In a first step, the status quo CRT recycling scenario in the studied region was investigated by visiting and interviewing the recycling companies assessed in the MFA phase. This allows for the investigation of the current possibilities and problems in the recycling of CRT devices and thus for
the definition of the starting point of each of the recycling scenarios.
To define alternatives to the baseline scenarios first the existing best available technologies (BATs)
for the recycling of CRTs were investigated by field studies and interviews as well as literature
study and visits at European CRT recycling facilities. The aim was to receive a general overview
over the current best available technology (BAT) and best practice (BEP) of recycling technologies
for CRT screens.
Keeping these BATs in mind, the industry in the studied region as well as other South African companies, which may have the technology to reuse or recycle CRT glass, were interviewed by phone
calls and questionnaires to investigate their ability to handle the CRT glass. This led to an overview
of the current best available technology overseas and possible pathways in the studied region and
in South Africa to recycle CRT glass. Based on this overview the recycling scenarios for the CRTs
in the CMA were specified.
The recycling scenarios include pre-processing steps (such as separating or crushing) and the
main recycling process also. In addition, transportation processes for the CRTs and the products
were included in the evaluation process.
Once the scenarios were defined, they were assessed towards sustainability using the Multi Attribute Utility Theory (MAUT) described in section 2.3. With the MAUT results the scenarios were
Dominik Zumbuehl
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compared to each other and proved on their robustness using a robustness analysis considering
error analysis and error propagation described in section 2.4
2.3
Multi-Attribute Utility Theory (MAUT)
The methodology of the MAUT is retrieved from the book “Embedded Case Study Methods”
(Scholz et al., 2002). Multi-Attribute Utility Theory is a label for a family of methods. These case
evaluation methods are used for analyzing, evaluating and comparing different alternatives. “The
objective of the MAUT is to obtain a conjoint measure of the attractiveness (utility) of each outcome
of a set of alternatives” (=scenarios). The outcome (=utility) of each scenario can then be compared among all scenarios.
Within the MAUT the overall attractiveness of an alternative is decomposes into a number of attributes. Attributes are preference-related dimensions of a system and can be system variables, but
can also measure quality or aesthetics.
Once all alternatives have been rated according to all attributes, MAUT composes the ratings and
organizes a synthesis resulting in a one-dimensional utility measure. The multi-attribute decomposition obeys the following definitions:
• The set of scenarios (recycling-alternatives)
S = (S1,S2 , Si , ... ,Sm )
• The set of attributes
a = (a1,a2 , a j , ... ,am )
• The scenario vs. attributes matrix
Mi,j = a j (Si ) )
• The set of utility functions
U = (u1,u2 ,u j ,..,um ), u j = f(a j (Si ))
• The set of importance weights
W = (w1,w 2 ,w j ,..,w m )
The composition rule is the weighted sum of the utilities.
m
m
j=1
j=1
U(Si ) = ∑ w ju j (a j (Si )) = ∑ w ju j (Mi,j )
(7)
As indicated above a set of scenarios has to be defined. The scenarios evaluated in this study are
described within the MAUT assessment (see section 4.2) and are not discussed any further in this
section.
The process of the definition of a set of attributes intends to cover all aspects of the evaluation of
the scenarios. The definition process can be carried out for instance by a study team or a group of
stakeholders. In this study the attributes were defined by the author and reviewed by a group of ewaste professionals. The attributes represent economic, environmental and social criteria. They are
specified in section 2.3.1.
Before the composition of the values from each attribute to the overall utility of a scenario, the attributes have to be weighted by the corresponding group of decision makers or stakeholders involved in the scenarios evaluated. The process of the weighting of the attributes is defined in section 2.3.3.
2.3.1
Attributes used in the MAUT assessment
In this study the overall aspect of the recycling scenario evaluation is defined by the term “sustainability”. The 1995 World Summit on Social Development (United Nations, 1995) defined this term
as "... the framework for our efforts to achieve a higher quality of life for all people …" in which "…
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economic development, social development and environmental protection are interdependent and
mutually reinforcing components".
There was no set of attributes found which could be adopted for this study to evaluate the recycling
of e-waste in developing countries towards sustainability. An attempt to define attributes for the
assessment of e-waste management systems was carried out in a study by Widmer et al., (2005).
Among others they defined criterions and attributes for e-waste recycling systems including the
assessment of material flows, technologies and financial flows. In addition, attributes for the
evaluation of impacts on the environment and the human health were defined.
Corresponding to the above definition of “sustainability” in this study each scenario will be evaluated using a self-defined set of attributes defined by the author and a core group of e-waste professionals consisting of both Swiss and South African members. Note: a set of attributes should
consider all aspects of sustainability and objectiveness of the team that defines the attributes is
required. However, the definition of a set of attributes always undergoes subjectiveness. In addition, the more attributes allocated to a certain aspect of a problem the higher is the contributon of
this aspect to the overall utility of a certain scenario.
Table 1 shows the attributes and the scale / unit used for the MAUT assessment. For some of the
attributes data were measured or calculated and for others only semi-quantitative analysis based
on estimates was carried out. Keeping those attributes in mind the following set of attributes was
defined for the assessment of CRT recycling scenarios.
Attributes
Scale / unit
Indicators involved
Low net costs
$ / kg CRT
Costs for transport, processing and labour vs. revenues
Low capital costs
$ / kg CRT
Investment costs for additional plants and technologies
used in a scenario
Increased potential for local economic growth
0, 0.25, 0.5, 0.75, 1
Additional industries and services involved by implementing a scenario
Economic attributes
Environmental attributes
Low use of electricity
Low fuel use for transport
Low use of freshwater
Normalized Ecoindicator 99 points (=
sum of environmental
losses and environmental benefits)
Savings of electricity but also energy in general by
implementing a scenario
Fuel used by shipping and road transport
Freshwater consumption of a recycling scenario
Caused vs. prevented emissions according to the savings of raw materials calculated with eco-indicator ‘99
Remaining waste of a scenario which has to be landfilled in the CMA
Little (toxic) emissions
Minimum of waste volume to landkg / kg CRT
fill
Social attributes
Creation of jobs for the previously
unemployed in the CMA
Creation of highly skilled jobs in
the CMA
Working hours / kg CRT
Working hours for low-skilled and semi-skilled workers
generated in the CMA
Working hours for highly skilled workers generated in
the CMA
Creation of jobs outside SA
Working hours generated outside South Africa
Low health & safety impacts
0, 0.25, 0.5, 0.75, 1
Impacts of a scenario on health and safety of the employees engaged in a scenario.
Table 1: The attributes applied in the MAUT assessment
Following the attributes presented in Table 1 are described in depth.
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Economic attributes
Low net costs: This attribute represents the overall costs for a recycling system in this scenario. It
includes the costs for the transportation, labour, the pre-processing or the final disposal of the CRT
glass as well as the revenues for products sold to the industry. The net costs are defined differently
in every scenario. Low net costs mean a high utility.
Low capital costs: This attribute includes the investment costs needed if a new plant or technology
is used in a certain scenario to process the CRT glass. Same here, low capital costs leads to a
high utility.
Increased potential for local economic growth: The values for this attribute were assessed only
qualitatively. It was assessed considering industries involved by a certain scenario. For instance if
long transport distances are required and new plants are established using local technology and is
operated and maintained locally then the potential for local economic growth is increased. An increased potential for local economic growth implicates a high utility.
Environmental attributes
As indicated in Table 1 the environmental utility was intended to be assessed by the evaluation of
the attributes: “Low use of electricity”, “Low Fuel use for transport”, “Low freshwater use” and “Little
toxic emissions”. However for the assessment of the environmental attributes the Eco-indicator 99
(Goedkoop et al., 2000) was applied. The Eco-indicator 99 (EI ‘99) is a more powerful tool when it
comes to the assessment of environmental impacts than the measurement of only four attributes
because the Eco-indicator 99 is able to assess the complex coherences between technology and
environment. The EI ‘99 is a damage to human health, ecosystem quality and damage to resources
oriented method and provides a aggregated and weighted indicator (see Figure 3 for a general
derivation of environmental impact indicators). The inventory data were collected from the ecoinvent 2000 database (ecoinvent Centre, 2005). This database contains Life Cycle Assessment
(LCA) based inventory data mostly for European settings (electricity mix, technologies, etc.). Also
for the recycling processes designed to be processed in South Africa also these inventory data
were applied. EI ‘99 is a LCA-based indicator in terms of a cradle to grave evaluation of goods and
processes. As in this study, the assessed scenarios were not described by a cradle to grave approach a different method was developed to include the EI ‘99 indicators in the MAUT assessment
that is specified in the following.
In accordance to the QWERTY/EE concept developed by Jaco Huisman (2003) the environmental
assessment was carried out by adding the environmental impacts (losses) of the recycling scenario
with the environmental benefits (gains). Environmental gains occur when a recycling process leads
to for instance to a replacement of raw materials or to energy savings by using CRT glass instead
of the conventional input. Contrary environmental loss occurs when for instance more waste is
produced by using CRT glass instead of the conventional input in a process. Figure 2 indicates the
principle of the environmental gains and losses by using CRT glass in a process. With this approach the overall EI ‘99 was calculated by adding the several environmental gains and losses of
the processing of CRT. Positive values for environmental losses and negative values for environmental gains were allocated to derive the overall EI ‘99 score.
n
m
i=1
j=1
EI' 99 = ∑ EGi + ∑ EL j
(8)
With
EI’ 99 = Aggregated environmental indicator for a scenario
EGi
= Environmental gain
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METHODS
ELj
= Environmental loss
Systemborder
Raw Materials
SAVINGS
1 kg CRT
ADDITIONAL
Energy used
Water
SAVINGS
Process 1
Process 2
ADDITIONAL
Emissions
ADDITIONAL
Waste
good
Figure 2: Example of two processes involved in the processing of CRT screens. Additions of energy or emissions lead to an environmental loss and savings in raw materials or water lead to an environmental gain
In addition the results from the Eco-indicator 99 were compared with the Impact 2002+ methodology (Jolliet et al., 2003) which is also a life cycle based method for the assessment of environmental impacts. This method aggregates the impacts on climate change, aquatic ecotoxicity, terrestrial acidification and nutrification, terrestrial ecotoxicity and human toxicity. The intention was to
compare the outcome of the environmental impact assessment of the evaluation of the recycling
scenarios with a different method.
Figure 3: General procedure for the calculation of Eco-indicators. The light coloured boxes refer to procedures, the dark coloured boxes refer to intermediate results. Source: (Goedkoop et al., 2000).
As declared in the Polokwane Declaration (Government of South Africa, 2001) the minimization of
waste in general and even the “zero waste” strategy is strived. In addition the fact that most of landfills are nearly full (Essop, 2005) led to the attribute “Minimization of waste volume to landfill”. This
attribute was added to the environmental attributes and was not assessed within the Eco-indicator
99. A low volume of remaining waste to landfill means a high utility.
Social attributes
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Creation of jobs for the previously unemployed in the CMA: In South Africa the unemployment rate
is high (see section 3.1.1). Therefore, the creation of jobs for the previously unemployed is important when establishing a certain recycling scenario in the CMA.
Creation of highly skilled jobs in the CMA: In addition to the job creation potential for the previously
unemployed, the job creation potential for highly skilled is also included in the assessment.
Creation of jobs outside SA: Some of the alternatives also create jobs outside South Africa. Those
jobs are also included in the MAUT assessment.
For all these social attributes, a high value means a high utility.
Low health & safety impacts: The CRT glass contains hazardous substances (see Appendix 10).
Thus it is important that the scenarios are assessed towards the health and safety impacts on employees carrying out the work in a certain scenario. Like the attribute “Increased potential for local
economic growth”, this attribute is not measurable directly and thus was assessed semiquantitative using the scale shown in Table 1. A high score here entails a low utility.
2.3.2
Normalisation of attributes
One disadvantage of the MAUT is that a utility of one attribute is per se not comparable with a utility of a different attribute due to different units and scales. Thus to make the attributes comparable
they have to be transferred into the same scale. This was achieved by normalizing the values of an
attribute over all scenarios. For all the attributes for which its value is proportional to its utility (e.g.
“creation of highly skilled jobs in CTN”) it follows:
an =
ai - amin
amax - amin
(9)
And if the value from an attribute is reciprocally proportional to its utility (e.g. “net costs”) than
an = 1an
ai
amax
amin
ai - amin
amax - amin
(10)
= Normalized value of an attribute of a certain scenario
= Value of an attribute of a certain scenario
= Maximal value of an attribute over all scenarios
= Minimal value of an attribute over all scenarios
The resulting range for the values of an is between 0 and 1 whereas the normalized lowest attribute
value becomes 0 and the highest 1 respectively. Hajkowicz (2006 ) also used this approach for the
linearization of attributes for the MAUT assessment.
2.3.3
Weighting of attributes
The weighting of the attributes was carried out subsequent to presentations and the discussion of
the CRT screen recycling problematic and the recycling alternatives at a Workshop at the University of Cape Town. Participants were local professionals and stakeholders involved in the CRT
recycling issue. This group consisted of: consulting engineers, scientists, waste managers, a supplier of IT equipment, technicians and engineers involved in a computer refurbishment project (not
locals), government representatives and representatives from an environmental NGO. A representative of a lead smelter (industry) also participated but he did not participate in the workshop. The
questionnaire and the results of the weighting are listed in Appendix 15 and Appendix 16 respectively. Table 2 shows the transfer scale from the audiences’ weights into the MAUT assessment.
Dominik Zumbuehl
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Audience’s weight allocated to the attributes
No importance
Little importance
Medium importance
High importance
Very high importance
Values used in the MAUT assessment
0
1
2
3
4
Table 2: Transfer scale for the weighting in the MAUT assessment
Note: The overall weight for the weighting of the Eco-indicator 99 results was derived from the
weights given to the corresponding environmental attributes (see Table 1) by adding those weights.
The reason was that in the aggregated value of the Eco-indicator 99 all these attributes are represented.
2.4
Robustness Analysis
In order to prove the utilities of different scenarios on their robustness an error analysis as well as
an error propagation was carried out. Thus it is possible to calculate upper and lower boundaries of
the MAUT utilities to compare the variations of the alternatives and thus their robustness. The
steps in the analysis of the robustness include error analysis and error propagation.
2.4.1
Error analysis and error propagation
The MAUT assessment depends on a big set of input data. Input is generally subject to sources of
uncertainty including errors of measurement, absence of information and poor or partial understanding of the driving forces and mechanisms. Thus, the analysis of the error of input data and
particularly the promulgation of the errors within a calculation of a specific value for an attribute is
essential. In this study, the errors for all input parameters were specified using a semi-quantitative
scale defined in Table 3. For measured or estimated input parameters, a relative error was allocated according to the reliability of the data source and due to natural variability in the several parameters. 10% error was allocated when the data for the input parameter was reliable and the
variations are low (e.g. transport distances). 25% error was allocated if the parameter either was
slightly variable or stems from good estimates (e.g. all Eco-indicator 99 values). 50% was allocated
to parameters, which were estimated roughly or can vary widely (e.g. some transport cost parameter). 100% were allocated when the figures were estimated without any informative basis and / or
the parameter was supposed to vary widely.
Semi-qualitative attributes (e.g. increased potential for local economic growth) were varied by +/0.1 points and for parameters where the value is by definition 0 (e.g. for the parameter which contribute to the attribute “Creation of jobs outside SA” in a South African scenarios) no error was allocated.
The allocation of the errors for all input parameters is shown in Appendix 12.
Level of reliability of input parameters
Reliable
Reliable
Quite reliable
Not very reliable
For semi-quantitative values (0, 0.25, 0.5, 0.75, 1)
variability
Low
Middle
Middle
Middle to high
Relative error allocated [%]
10
25
50
100
+/- 0.1 points
Table 3: Allocation of relative error to the input parameters used for the MAUT assessment
Once the allocation of relative errors to the input parameters was carried out the error propagation
was completed in order to assess the overall error generated by the calculation of a value for a
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specific attribute. The error propagation was carried out according to an online tutorial for students
(Windischbauer, 2005) and a web page by the Rochester Institute of Technology (Lindberg, 2000)
and was adopted accordingly in this study.
Since in this study additions and subtractions as well as multiplications and divisions were used to
calculate the values for the MAUT attributes, the following basic rules were applied:
For additions and subtractions, z = a + b - c the absolute errors are summed up:
Δz = Δa + Δb + Δc
(11)
to then calculate the relative error using:
Δa + Δb + Δc
Δz
=
z
a+b−c
(12)
Whereas
Δ z = absolute error
Δz
= relative error [%]
z
For multiplications and divisions z =
a × b
, all the relative errors are added to derive the relative
c
error in the result that is
Δz
Δa Δb Δc
+
+
=
z
a
b
c
(13)
Whereas
Δz
= relative error
z
Δa Δb Δc
,
,
= relative errors of the factors a, b and c [%]
a
b
c
2.4.2
Determination of the upper and lower bounds of the MAUT utilities
With these basic rules of error propagation, upper and lower limits of the values for the attributes
for each alternative can be calculated using:
amax = a × (1 +
Δz
Δz
) and amin = a × (1 )
z×2
z×2
(14)
Whereas
a
= calculated value of a utility limit of an attribute
amax = upper limit of an attribute
amin = lower limit of an attribute
The upper and lower limits for the attributes were then included in the MAUT assessment to derive
the boundaries of each utility of the assessed scenarios. The limits were again normalized and
weighted to make them comparable with the MAUT results. Note: the upper and lower values were
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normalized using the existing maxima and minima from the corresponding attributes to achieve a
ceteris paribus situation according to the theory described in section 2.3.
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RESULTS - MASS FLOW ASSESSMENT
3
MASS FLOW ASSESSMENT
This section presents the results from the mass flow assessment. In section 3.1 the system is defined by a description of the case study region within the MFA was carried out (see section 3.1.1).
Then the players involved in the MFA are specified and described from section 3.1.3 until section
3.1.9. Subsequently a short description of the composition of CRT devices such as monitors and
TVs is shown. Finally, the mass flows and the corresponding time series for both CRT monitors
and CRT TVs are presented in section 3.3 until section 3.6.
3.1
System Definition
3.1.1
Selection of case study region
In this section, the case study region is described
geographically but also a brief economic and
social overview is given.
The information presented in this section are
mainly retrieved from the Official Trade and Investment Promotion Agency of the Western
Cape (WESGRO, 2005) as well as from the Department of Environmental Affairs and Development Planning (Essop, 2005).
South Africa
CMA
Western Cape
Figure 4: South Africa (grey), Western Cape (dark
The Western Cape Province contributes with grey) and Cape Metropolitan Area (CMA) in the very
nearly 15% of the South African national output south-western tip of South Africa) source:
http://de.wikipedia.org/wiki/Kapstadt
(GDP) and attracts over 16% of foreign direct
investment. The strength of the Western Cape
lies within its people, diversified economy, modern infrastructure and the ability to compete in the
international arena. The Western Cape Province
is located in the south west of South Africa,
boasting one of the most diverse, dynamic and
innovative economies in Africa. Since the late
1990s, South Africa has been experiencing an
historic economic upswing. The economic growth
of the Western Cape was projected to be 4% in
2005. Despite the outstanding economic characteristics, 28% of the Western Capes population
still lives in poverty. White highly skilled individuals are the highest earners with inequalities between racial groups getting worse. 90% of the
population within is urbanised. The urban areas
of the Western Cape are dominated by the Cape
20km
Metropolitan Area (CMA) with its capital Cape
Town.
The CMA lies in the very southwestern end of the
Western Cape. It comprises of 3.3 million inhabitants (est. in the year 2005) which are 64.0% of
Figure 5: Cape Metropolitan Area, source:
http://www.environment.gov.za/
Dominik Zumbuehl
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the Western Cape’s Population. 4.3 million people are expected to live in the CMA by the year
2031 assuming an average growth rate of some 1.00% (Dorrington, 2000). From the total of
800’000 households within the CMA 18% are informal dwellings (townships) using either paraffin
candles or electricity for lighting. In 2004, the unemployment rate was 29% with a labour force of
1.4 million people out of 2.1 million adults (15-64 years).
The CMA comprises a socio-economic region that is highly aggregated. It links the economic structures of the City of Cape Town with the surrounding municipalities of the CMA. It includes the municipalities of the City of Cape Town, Blauwberg, Tygerberg, Oostenberg, South Peninsula and
Heidelberg shown in Figure 5. The CMA contributes with 76% to the Western Cape’s GDP. Despite
a high unemployment rate as well as a high level of informal dwelling, the CMA is the second largest economic centre in South Africa after the Gauteng Province.
3.1.2
Players in the case study region
Following the players involved in the CRT flows within the CMA are shown in Figure 6. Since there
is no CRT manufacturer in South Africa, all CRTs either from computer monitors or TVs are imported to South Africa (Coetzee, 2006).
Manufacturer
Distributor
TVs
Consumers
Desco
PHILIPS
SAMSUNG
SONY
Corporate
Distributor
Monitors
Private
AXIZ
PANASONIC
LG
MECER
DEAWOO
EIZO
MAG
PROLINE
Gigabyte
IBM
Footprints
Recycling IT
Government
MUSTEK
Sahara
SINOTEC
Collectors
Drop Off
MSW
Drive Control
Refurbisher of
TVs
Incredible
Pinnacle
?
Tarsus
Recoverers /
recyclers
Annex
SA Metal
Equity
Desco
Rectron
Salvagers
MICO
Second hand
suppliers
Landfills
FreeCom
Vissershok
Smart City
Coastal Park
Device SA
Bellville
Recycling IT
Faure
System border
Figure 6: System picture with the players involved and their relationship to each other in the mass flows of
computer monitor s and TVs CMA.
3.1.3
Manufacturers, Distributors and Import Statistics
The major brands manufacturing CRT devices that are distributed to the CMA customer base are
shown in Figure 6. The names of the major brands were evaluated by visiting retailers and private
households and according to an interview with an IT professional (Newson, 2006). To both manu-
Dominik Zumbuehl
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facturers and distributors of CRT monitors questionnaires (see Appendix 6) had been sent to find
out the current and past sales figures, market shares, the average CRT size/weight and future
sales trends. Assuming that the sales figures of the CMA’s manufacturers are equal to the sales
figures of the distributors there were two opportunities to assess the figures of CRTs entering the
CMA.
None of the manufacturers was willing or prepared to share any of the information based on the
questionnaire. Only four of the 11 CRT monitor distributors were willing to share sales figures
based on the questionnaire and e-mail correspondence. With the available data and the market
shares of two of the main players in the CMA a quite reliable estimate of the current (2005) sales
figures was carried out.
For the assessment of the TVs entering the CMA, import statistics from 1992 to 2005 were used.
They were provided by the Department of Trade and Industry (DTI, 2006) and by the South African
Revenue Service (2006). As those import figures only contain aggregated values from the entire
South African market a factor to estimate the CMA based figures had to be determined. This factor
was derived from the fact that the Western Cape contributes with 15% to the national GDP and the
CMA wit 76% to the Western Cape’s GDP (WESGRO, 2005). Thus, the factor to derive the CMA’s
TV import figures was calculated as follows:
fCMA = GDPWC × GDPCMA = 0.15 × 0.76 = 0.114
(15)
fCMA = factor to derive CMA figures from national import figures
GDPWC = share of the Western Cape’s Gross Demand Product in the national Gross Demand product
GDPCMA = share of the CMA’s Gross Demand Product in the Western Cape’s Gross Demand product
Only overall CRT import figures were available as well as the import figures for CRT video monitors. Thus, the numbers of CRT video monitors had to be discounted to derive the number of CRT
TVs. Although there were many monochrome (black and white) sets imported, only the colour TV
sets were used in the MFA. Appendix 4 shows the import figures from 1992 to 2005. The export
figures had been discounted from the import figures to reach the overall numbers of CRTs sold to
the CMA customer base.
3.1.4
Second hand suppliers
In the CMA there are a few second hand suppliers who take back obsolete computers and refurbish them for the secondary market or donate these computers to some institutions. FreeCom is
the largest computer refurbisher in the CMA. They possess a market share of almost 100%
(Scholz, 2006). FreeCom imports used computers mainly from the Netherlands and the United
Kingdom. They receive about 500 monitors on a monthly base. Some 100 new CRT monitors from
suppliers like Gigabyte and Proline have to be purchased every month additionally. They sell
around 600 CRTs per month since the year 2000 to their CMA based customers.
Device SA imports obsolete computers from Europe. They sell their refurbished computers and
monitors mainly in the Gauteng Province. Only between 0 and 50 monitors are sold in the CMA per
month (Mensing, 2006).
Recycling IT is an initiative, which assists equipment users with specific queries or problems related to e-Waste. The aim of Recycling IT is “… to develop Cape Town as a blue print model for the
entire Western and Northern Cape. A collection and disposal infrastructure is currently being developed by Recycling IT, in partnership with the current Green e-Waste Channel facilitator, private
Dominik Zumbuehl
29
October 2006
business (such as retailers) and the local authorities. Recycling IT is already involved in testing any
e-waste received either at Footprints, (a community based recycling centre), through municipal and
retailer collection points or by pre-arranged collection from private customers. Where computer
equipment is involved, Recycling IT ensures that all client data is fully removed during the testing
process prior to it being passed on for commercial retrofit, donation or resale to various e-waste
entrepreneurship and charity programmes, who utilise it either as is, repair, rebuild, strip components or make products from e-waste which can be sold.” (Dittke et al., 2006). Recycling IT passes
on some working monitors for second hand usage, but most are currently stockpiled whilst they
continue to search for a satisfactory solution to the CRT waste disposal problem.
Smart City is a governmental refurbishment organization, which collects the obsolete computers
from all the seven administrations of the City of Cape Town. They refurbish some 250 computers
per month and donate some of them to libraries, schools and community centres. Many of the CRT
monitors and computers are stockpiled in Cape Town and in Ndabeni (Tatana, 2006). No figures of
stockpiled monitors in Ndabeni were available.
Computers being set up for reuse
Employee at work setting up a PC
CRT monitor Stockpile at Smart City
Figure 7: Smart City refurbishment centre in Cape Town, refurbishing activities and stockpiles of CRT monitors.
3.1.5
Consumer
The consumer based CRT flows and the consumer stock growth of TVs and computer monitors
were calculated based on the information collected from the suppliers, the recycling companies and
the landfill figures. No consumer-based survey was carried out to assess the flows from and to the
consumers.
3.1.6
TV refurbishers
According to Desco Electronic Recyclers, many TV refurbishers in the CMA collecting broken or
obsolete TVs and repair them. However the flows to and from these refurbisher were not investigated in this study due to time restrictions.
3.1.7
Collectors
Four major collectors of the municipal solid waste (MSW) are currently present in the CMA. EnviroServ (Pty) Ltd, Inter-Waste (Pty) Ltd, Wasteman and Waste Control. Only Wasteman was prepared to share any numbers or estimates of e-waste collected within the municipal solid waste
(specified in section 3.1.9). The e-waste picked up by MSW-collection is disposed of in the four
remaining landfill sites in the CMA (Coastal Park, Bellville, Faure and Vissershok). They do not
separate any e-waste or assess the e-waste content. According to an interview with Saliem Haider
Dominik Zumbuehl
30
October 2006
from the City of Cape Town Waste Department (Haider, 2006) and all of the major waste managers
(Kriek, 2006; Novella, 2006; Willcocks, 2006) there are currently no figures of e-waste in the MSW
stream.
With the recently established drop-off container for electronic waste (see Figure 9) in the Wynberg
drop-off centre e-waste can now be disposed of. It is planned to establish eight more of these containers in several Cape Town based drop-off sites by 2008.
Footprints in Wynberg runs a “waste-to-art” community centre and acts thereby as a collection centre for e-waste. Footprints does also collect container glass and metals for the further recycling.
They dismantle some of the received computers to produce art of the several components (see
Figure 8) and some are refurbished at recycling IT. Both the Wynberg drop-off site and Footprints
received together in the first 3 month from January to March 2006 around two tons of e-waste. 40%
were processing units (computers) 40% monitors (800 kg) and 20% others e-waste. From April to
June 2006 four tons of e-waste with a composition of 30% processing units, 50% monitors (2000
kg) and 20 % miscellaneous e-waste (Newson, 2006). 2800 kg monitors with an average weight of
14.7kg (see Table 4) results in approx 200 monitors collected in 6 months. No televisions sets were
collected. The public launch of the drop-off site in Wynberg was on 14 June 2006. A newspaper
article on 15 June was published which led to a bunch of e-waste dropped off in the following
weeks.
Manual dismantling of a PC at Footprints
Clocks made of hard disks and printed
wiring boards (PWBs)
Worker is producing earrings.
Figure 8: Worker is dismantling a computer at Footprints. Clocks and earrings are some products of the recycling activities.
Wynberg Drop-off Centre, 20 feet
Container for e-waste
Mostly Monitors and personal computers are disposed of
Launch e-waste container: donator (l.)
with the initiator (r.)
Figure 9: The first container designed to dispose of e-waste in the CMA at the Wynberg Drop-off Centre.
3.1.8
Recyclers
Desco Electronic Recyclers, a Recycling company with head office in Johannesburg, is the only
professional e-waste recycler in the CMA who collects and processes CRT screens. Desco is in
Dominik Zumbuehl
31
October 2006
business since 2001 and runs a stripping facility in Kraaifontein near Cape Town (see Figure 10).
Currently they strip 300 to 500 obsolete CRT units per month. Only some 10 TV sets are collected
monthly. 90% of the CRTs are collected from private households and industry. 10% stem from
distributors and a local second hand supplier.
They sell the products partly to their head office in Johannesburg and partly to local scrap dealers.
There is no market for the stripped CRT tubes. They used to send them from Cape Town to Johannesburg assuming that there will be a market for the tubes in the near future. But since there is
no market for the tubes, they just landfill it locally. To send a “super link” truck up to Johannesburg
they pay about R12’000. This lorry can transport some 50 tons, which is roughly estimated similar
to some 5’000 tubes (assuming an average weight of 14.7 kg per monitor and a glass content of
60%).
Today Desco transports about 150 CRTs per load on a trailer to the local landfill site. The disposal
costs for the stripped CRTs are around R200 per ton of CRT at Vissershok landfill site (Novella,
2006) transportation and labour costs not included.
There is a market for the plastics from the CRT housings, the copper, ferrous metals and for the
printed wiring boards (PWBs). The metals are sold to a local metal scrap dealer, the plastics and
the PWBs are sold to Desco Johannesburg.
Local TV repairers collect the TVs at Desco and fix them to put them back on the second-hand
market. Thus from Desco no TV tubes are disposed of at the landfill site.
Monitor stock pile at Desco in Kraaifontein near Paarl
Collected printed wiring boards
(PWBs) for the further recycling
Another monitor stockpile
Manual dismantling of a Monitor
Monitor casings stockpiled at Desco
Trailer for the transport to the landfill
site
Figure 10: CRT monitor stockpiles and stripping at Desco Electronic Recyclers in Kraaifontein near Paarl.
3.1.9
Landfilling
Solid waste outputs in Cape Town are increasing at 1.8% per annum (Essop, 2005). Four of the
former seven landfill sites are still in operation (Coastal Park, Bellville, Faure and Vissershok)
(IWMP, 2004) and are located in the Cape Flats. A valuable groundwater layer underlies this zone
(Essop, 2005). As most of these landfills are nearly full the potential of this layer to be polluted by
hazardous waste becomes more and more a serious threat.
Dominik Zumbuehl
32
October 2006
Only the Vissershok hazardous landfill site is allowed to manage hazardous waste. Wasteman that
possess a 50% share of this landfill site was able to share any numbers of e-waste collected and
disposed. They estimate to collect and dispose of some 200 to 300 CRT units per month (Novella,
2006). All other waste managers do not collect any e-waste and were not able to estimate any figures of e-waste dumped within the municipal solid waste stream. The amount of e-waste collected
by the municipal solid waste collection, by e-waste recyclers or private and corporate customers
has not been reported yet. According to the landfill managers of the four mentioned landfill sites
there is almost no e-waste disposed of but they all were not able to even roughly estimate the
amounts. According to the landfill manager at Coastal Park landfill site, there is “next to nothing” ewaste dropped off at that landfill site (Nomdo, 2006). A short interview with a “salvager” on the
Coastal Park landfill site (see Figure 11 upper pictures) brought some additional information. They
collect about 50 monitors and TVs in a year mostly monitors. They strip them and sell the metals to
scrap dealers. The CRTs, the casings and the PWBs remain on the landfill site.
A visit at the Athlone Refuse Transfer Station in Bellville (see Figure 11 lower pictures) unveiled that
there is not much of e-waste disposed of. They assume that during the night time when the site is
unsupervised some e-waste is disposed to avoid being charged for the disposal of hazardous
waste. Thus, a quite large number of unreported e-waste is supposed to be disposed of. However,
they were not able to estimate the amount of e-waste disposed of at the transfer station. During the
visit at the Athlone Transfer Station, no e-waste was detected but a single monitor casing.
Hence, it can be said that the streams of CRT monitors and TVs to the landfill sites in the year
2005 are very low. They consist of the 3600 to 6000 CRT monitor tubes from Desco, the 2400 to
3600 monitors collected by Wasteman and some 150 CRTs recovered by the salvagers on the
Coastal Park, Bellville and Faure municipal solid waste landfill sites. This results in an average
disposal rate of CRTs of about 7950 per year mainly CRTs from monitors.
Municipal solid waste at Coastal Park landfill site.
Salvagers at work. No electronic equipment was detected
Municipal solid waste at Athlone Refuse Transfer station.
Train with compacted waste for the transport to the Vissershok landfill site
Figure 11: Impressions from the Coastal Park municipal solid waste landfill site and from the Athlone refuse
transfer station
Dominik Zumbuehl
33
October 2006
3.2
CRT computer monitor and TV composition
To carry out a mass flow assessment one
needs to know the composition of computer monitors and TVs. Table 4 shows the
composition of a typical CRT computer
monitor and CRT TV. Many data from literature are available which contain information about the content of plastics, metals, PWBs as well as the chemical composition of the glass and the coatings within a
Cathode Ray Tube (i.e. panel glass, funnel
glass and the neck glass) (see also Figure
Figure 12: A CRT comprises the face plate (= front glass 12). Due to the variety in the size and comwith 2/3 of the tube’s weight), the funnel glass and the position of computer monitors and TVs, it is
neck. The solder glass (=frit) connects the neck and face
difficult to specify exact figures for each of
glass to the funnel glass
the components. In this study the average of the highest and lowest values found in literature was
taken to calculate the amounts of the various components in the MFA (Monchamp et al., 2001;
ICER, 2003; JRC, 2003; Huisman et al., 2004; ICER, 2004; Andreola et al., 2005; Kang et al.,
2005).
weight of fractions in a CRT computer monitor [g]
min.
max.
Components
average
# values
literature
literature
2
Plastics
2’599
2’607
2’603
2
Copper
892
892
892
1
Ferro
1’324
1’324
1’324
2
Aluminium
49
238
144
2
PWBs
385
1’385
885
1
Gun
28
28
28
3
CRT
8’428
9’392
8’910
4
Front glass
5’619
6’261
5’940
4
Funnel glass
2’809
3’131
2’970
1
Neck glass
45
45
45
1
Frit (solder)
45
45
45
1)
13’705
15’866
14’786
Total weight
2)
14’649
Weight
1
1) weight added up from the values in this table
2) average weight from literature.
eight of fractions in a CRT TV g]
min.
max.
average
# values
literature
literature
4
4’851
5’940
5’396
2
1’155
1’353
1’254
2
1’221
1’353
1’287
2
99
264
181.5
1
1’848
1’848
1’848
0
?
?
?
7
19’570
23’760
21’665
2
13’275
16’155
14’715
2
6’120
7’605
6’863
1
90
90
90
90
1
90
90
34’518
28’744
31’631
33’000
1
Table 4: Composition of a CRT computer monitor according to literature data
In this study for any weight based calculation a weight of 14.7 kg for CRT monitors and 33 kg for
TVs was applied respectively. For the weight of the CRTs 8.9 kg for monitors and 21.7 kg for TVs
was used.
Dominik Zumbuehl
34
October 2006
3.3
Mass flows of CRT computer monitors in the CMA in the
year 2005
Figure 13 shows the result of the MFA for CRT computer monitors in the Year 2005 in the CMA.
Due to uncertainties in the quantification of the flows, upper and lower limits were defined. The
figures represents computer monitor flows indicated in metric tons using 14.7 kg as the average
weight of a monitor and 8.9 kg for the stripped CRT respectively (see Table 4). A detailed table of
all monitor flows within the MFA can be found in Appendix 5. 1’466 to 1’723 t entered the CMA in
the Year 2005. 106 t were imported to the second hand supply market. 1’359 to 1’617 t of new
monitors were sold to the consumers as 109 to 125 tons of second hand monitors were sold. 46 to
50 tons are estimated to reach the second hand supply from the consumption at consumer level.
53 to 89 t go to the recycling. From there 3 to 5 tons of copper, 5 to 8 t of ferrous metals and 1 t of
aluminium are sold to the scrap metal market. 9 to 16 t of plastics and 3 to 5 t of PWBs and cables
are shipped from the recycling out of the CMA. In 2005, the consumer stock growth amounted to
1’333 to 1’550 t and the stock growth at the second hand suppliers adds up to 31 to 43 tons. The
landfilling from the consumption at customer level amounts to 35 to 53 tons and from the recyclers
53 to 89 tons respectively. 0 to 1 ton is salvaged on the landfill sites. The landfill stock grew with
some 67 to 105 tons in the year 2005.
106
106
Second hand
supply
43
31
stock
125
109
1723
1466
Distribution
(new & used)
1617
1359
xyz
process
yyy
upper limit [tons]
xxx
lower limit [tons]
50
46
Consumption
at consumer
level
1333 / 1550
stock
Copper
3/5
Ferro
5/8
Aluminium
1/1
89
53
Recycling &
Salvaging
1
0
53
35
Plastics
9 / 16
PWBs & Cables 3 / 5
53
32 CRTs only
Landfil
106
66
systemborder
stock
all units are specified in metric tons
Figure 13: Mass flows of computer monitors in the CMA, 2005; [metric tons]
Dominik Zumbuehl
35
October 2006
Discussion
For the computer monitors relatively unreliable sales figures for the years 2005, 2004 and 2003
were available. Neither sales data from the manufacturers nor custom statistics for CRT monitors
were available. Sales figures were assessed by sending the questionnaire presented in Appendix
6. Only 4 of 11 distributors were prepared to share any sales figures and only 2 of those 4 were
willing to provide any market share data. Thus, it was only possible to assess the overall input of
CRT monitors by using the sales figures and the corresponding market share data (see section
2.1.2 for the methodology). The total sales figures in the CMA were different when applied on the
two players providing sales figures and market shares. This led to an upper and a lower total sales
(1’466 and 1’723 tons respectively). In addition to this error, it is likely that the distributors also sell
the monitors to other distributors and not only to retailers. This could lead to an over estimation of
the input figures in the MFA. Thus to derive more precise data all sales figures from distributors
and those from the retailers should be obtained.
The flow from distribution to second hand supply is based on the figures of FreeCom, which possess a 100% market share in the CMA. Presumably, there are some other second hand dealers in
the CMA but none was found during this study. The flow from the consumption at consumer level to
the second hand supply is mainly generated because of the refurbishment activities at Smart City
from the governmental monitor stock. The stock growth in the second hand supply process is also
assessed from figures provided by Smart City.
Flows from the consumers to the recycling stems from the monitors collected by Desco Recyclers.
As they collect 300 to 500 units per month, the flow ranges between 53 and 89 tons. The flows of
copper, ferrous metals and aluminium as well as the flows of plastics and PWBs are derived from
the composition given in Table 4. It is likely that there are additional small flows from other recyclers to the landfill but according to Desco Electronic Recyclers, they are the only professionals
who collect and process e-waste in the CMA. Thus, additional flows from recyclers to the landfill
are expected to be very low.
Flows form the consumer to the landfill was calculated using the figures from the municipal waste
stream reported by Wasteman (Novella, 2006). As only one waste manager was able to estimate
the e-waste collected it is likely that this stream to the hazardous landfill site is larger than 35 to 53
tons. However, it is not expected that the stream to the municipal landfill sites is much higher since
the landfill mangers at Bellville and Coastal Park as well as the salvagers all agree that only a few
CRTs enter the municipal landfill sites.
This MFA clearly shows that though uncertainties in the flows from the consumption process to the
landfill there was a huge stock growth of computer monitors in the year 2005 in the CMA.
Dominik Zumbuehl
36
October 2006
3.4
Time series of CRT computer monitors
The modelling of the obsolescence of computer monitors was computed using the formula presented in section 2.1.2. As a basing point for the modelling the total sales of CRT monitors (Stot
described in the previous section) was used. From there the time series were calculated assuming
the following:
•
The World Development Indicator (WDI) starts with the listing of penetration rates for personal computers in 1988. Thus the year 1988 is considered as a starting point for the sales
of computer monitors to South Africa.
•
A linear development of sales figures for CRT monitors from 1988 to 2005 was assumed.
•
Until 2005 there was always an increase in CRT monitor sales (Humphreys-Davies, 2006;
Lancaster, 2006; Nel, 2006).
•
CRT monitor shipping will drop rapidly after the price for LCD monitors is <130% of CRTs,
which will be reached by 2007. The logic being that markets in the east will flog the last of
their production to the developing world once the Western developed markets no longer
demand CRTs – this will happen when economies of scale result in LCD’s being produced
at approximately 130% of the cost of CRT (Craig, 2006). Additional investigations revealed
that the price for CRT monitors compared to that of LCD monitors is with some 138% still
slightly above the trigger price of 130% according to the analysis of the world market price
for CRT and LCD monitors (Windowsmarketplace, 2006).
•
From 2005 to 2006 the sales figures are constant.
•
From 2000 to 2005 also the second hand market (FreeCom) started to sell computer monitors, assuming not to affect the sales figures from the rest of the market.
•
Leading manufacturers for the European market have indicated that recycling directives,
limitations of physical size, handling weight and energy efficiency imperatives will terminate
volume CRT based display production for European markets by about 2010 (JRC, 2003).
•
South Africa is one year behind the market development in Europe. Thus the South African
CRT monitor market will cease in 2011 (Craig, 2006).
•
From the year 2008 to 2011 sales will drop linearly to zero although after 2011, still a small
fraction will be sold (special applications like graphics arts industry).
•
A lifespan for a computer monitors of 15 years was applied to derive the obsolete computer
monitors (Scholz, 2006).
The above assumptions and estimates lead to the time series shown in Figure 14 for CRT computer monitors.
Dominik Zumbuehl
37
October 2006
Estimated sales figures CRT monitors
Yearly obsolete CRT monitors (life span =15 years)
2'000
sales figures
1'800
1'400
1'200
1'000
800
600
CRT monitors [tons]
1'600
400
200
0
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
2000
1998
1996
1994
1992
1990
1988
Figure 14: Time series of CRT monitors in the CMA. Estimated yearly obsolete CRT monitors (right) based on
the estimated sales figures and a lifespan of 15 years.
Discussion
According to Figure 14 some 250 tons of monitors should have become obsolete in 2005 but only
some 120 tons in average entered the recycling or landfill pathway (see Figure 13). 120 tons would
have been expected to become obsolete in the year 2003. This difference can have the following
causes:
•
The lifespan of 15 years for a CRT computer monitor is too short. If the lifespan had been
chosen only two years longer the time series would have fit perfectly with the MFA model.
This leads to the conclusion that a CRT computer monitor in the CMA has a lifespan of
about 17 years
•
Not all the disposal routes had been investigated in the MFA sufficiently. Thus, the flow of
CRT monitors to landfill was assessed incompletely. For example, it is very likely that more
CRT screens enter the landfill sites via the municipal solid waste stream or via the Athlone
Refuse Transfer Station during the nighttime rather than via the official disposing at Vissershok hazardous landfill site.
According to interviews with recyclers, e-waste experts and literature research, the lifespan of CRT
devices had been estimated. For CRT monitors, the lifespan is between 5 years (ICER, 2004) and
15 years (Apfel, 2006; Bradford, 2006; Gerig, 2006; Scholz, 2006). However looking at the results
of the MFA and the time series it seems that 5 years lifespan is clearly underestimated.
In this study, lifespan is defined as the period of time the CRT monitors is in use plus the time in
storage after the use-phase. The distinction between the use-phase and the storage-phase was not
completed in this study. For the assessment of the obsolete consumer stock, it would be therefore
important to investigate the proportion of the CRT monitors at consumer level in use compared to
the proportion in storage respectively. This would allow predicting more precisely the future obsolete consumer stock in order to be prepared when new recycling scenarios will be in place. According to Lombard (2004) most of the obsolete computers (in South Africa) are in storage after the
use-phase. The above MFA indicates that this is also the case for CRT monitors at least in the
CMA. It is assumed that many of the monitors in storage would be disposed rapidly once a public
recycling system is set in place. This assumption was recently confirmed as the drop-off site in
Wynberg was launched. This led to a significant increase in CRT monitors disposed of by the pub-
Dominik Zumbuehl
38
October 2006
lic and corporate (see section 3.1.7). Anyway it is likely that the yearly obsolete CRT monitors in
the CMA will increase dramatically until the year 2022 and will then drop rapidly.
3.5
Mass flows of CRT TVs in the CMA in the year 2005
Figure 15 shows the result of the MFA for CRT TVs in the year 2005 in the CMA. For the calculation of the weight-based flows, an average weight of 33kg for a TV was assumed (see Table 4).
2’607 tons of TVs entered the CMA in the year 2005, exported TVs excluded. It is assumed that all
the imported CRT TVs end up at consumption at consumer level.
The second hand suppliers for TVs in the CMA were not investigated thus it is not possible to say
anything about flows of TVs from or to second hand suppliers. According to Desco Electronic Recyclers, there are many TV refurbishers in the CMA which repair used TVs. Only some 0 to 5 tons
of TVs reached the landfill sites from the consumer level via the municipal solid waste stream. This
finding is derived from the salvager’s recovery rates, which is some 0 to 50 TVs a year on the
Coastal Park landfill site. As there are three remaining landfill sites for municipal solid waste this
amount was multiplied by 3 resulting in 0 to 150 TVs (0 to 5 tons) entering those landfill sites per
year. The salvagers strip the monitors and TVs up front and sell the ferrous metals, copper and the
aluminium to local scrap dealers. The PWBs, plastic casings, plastics (and wood) and the CRTs
remain on the landfill site.
Desco collects some 10 TVs per month. As Desco passes those devices to TV refurbishers, 120
TVs (4 tons) are estimated to reach the second hand market (reuse) from the recycler yearly.
Desco does not landfill any TV tubes.
xyz
Second hand
supply
yyy
upper limit [tons]
xxx
lower limit [tons]
x
x+4
2607
process
Consumption
at consumer
level
2607
Import - Export
2602 / 2607
stock
4
Copper
0 / 0.28
Ferro
0 / 0.19
Aluminium
0 / 0.03
4
Recycling &
Salvaging
5
0
0.55
0
0
Landfil
4.45
0
systemborder
stock
all units are specified in metric tons
Figure 15: Mass flow assessment of CRT TV sets in the CMA, 2005. All units are specified in metric tons.
Discussion
Dominik Zumbuehl
39
October 2006
The average weight of a TV was investigated by analyzing 250’000 collected TVs in Belgium in the
year 2003. The result was a weight of 33kg representing the average Belgian TV weight of obsolete TVs in the year 2003 (Huisman, 2005). For South Africa, no such average figures were available. However, the average weight for distributed and collected TVs in South Africa was set equal
to the European average of 33kg. In fact, the weights of TVs strongly depend on the screen diameters and vary from 10 kg up to some 90 kg (see Appendix 9). 33 kg corresponds to a screen size of
some 66 cm to 72 cm that is a very common screen size.
Neither sales figures from manufacturers nor from distributors were available. Thus import statistics
(custom statistics) from the South African Revenue Service SARS (Heyns, 2006) were used to
derive the amount of TVs entering the CMA. Those national figures were again multiplied by fCMA =
0.114 (see section 3.1.3) to derive the CMA based import figures as presented in. The export figures of TVs had been considered and were discounted from the import figures. In general the export figures were very low compared to the import figures.
Again, a striking consumer stock growth was determined since only a very small amount of TVs
was disposed at landfill sites around the CMA in the year 2005.
3.6
Time series of CRT TVs
Penetration rates from the year 1975 to 2001 (SABC’s first broadcasting was in 1976) and custom
statistics from 1992 up to 2005 were available (see Appendix 7 and Appendix 8). These figures
were used to derive the inputs of TVs in the CMA according to the methods described in section
2.1.3.
100'000
90'000
80'000
70'000
60'000
50'000
40'000
30'000
20'000
10'000
0
overall input
1'400'000
Data from WDI
1'200'000
Data from custom stats
1'000'000
800'000
600'000
400'000
200'000
overall input [units]
input per year [units]
input per year
0
2005
2003
2001
1999
1997
1995
1993
1991
1989
1987
1985
1983
1981
1979
1977
1975
Figure 16: Yearly inputs of colour TVs into the CMA based on World Development Indicators (WDI) and custom statistics.
Due to very unsteady yearly inputs (see Figure 16), the figures were transformed into a triangular
slope starting in 1975 with an input of 0 and peaking in 2005 with the methods described in section
2.1.3. The time series for the input function was calculated. It is shown in Figure 17. With this transformed, linear function the obsolete series was computed according to 2.1.3. An average lifespan
of 15 years and 25 years respectively for TVs in South Africa was applied.
Dominik Zumbuehl
40
October 2006
input per year
obsolete TVs (L = 15 y)
obsolete TVs (L = 25 y)
3'000
CRT TVs [tons]
2'500
?
?
?
2'000
1'500
1'000
500
0
2035
2032
2029
2026
2023
2020
2017
2014
2011
2008
2005
2002
1999
1996
1993
1990
1987
1984
1981
1978
1975
Figure 17: Time series of the input function of CRT TVs and their obsolescence using lifespans of 15 years
and 25 years respectively
TV sales forecasts
Since the market forecasts for CRT computer monitors are unambiguous, the forecasts for CRT
TVs differ much depending on the position of the forecasting person in the CRT market and the
region. For example the European Display industry Association says:
“…the game is far from being over for CRT makers! CRT remains the dominant technology used in
TV Sets and represents today (2004) 91%* of worldwide TV sales. Forecasts plan it to be still
around 80% (isupply) in 2007 volume wise …”. And: “... CRT makers are putting strong efforts in
new product development. Further to True Flat, which has become the major CRT technology,
CRT manufacturers are developing HDTV products on a worldwide basis to fulfil digital broadcast
requirements. Thanks to their cost advantages, CRT will have the right tools to fight against
Plasma and LCD …”(Trutt, 2005).
Other sources say that
“… the demand for CRT glass used in personal computers and televisions is projected to decline to
about 220 million units for the fiscal year ending December 2005, from around 272 million units in
fiscal 2004, due to a rapid shift towards TFT LCDs ...”(Asahi Glass Co. Ltd., 2005)
Thus at this stage it is not reasonable to forecast CRT TV trends because of the current discontinuous world market. Additionally as South Africa is a developing country adopting conclusions
from market forecasts in the developed world wouldn’t be reasonable. Hence the author resigns to
forecast the CRT TV inputs in the CMA.
Discussion
The input data from the World Bank World Development Indicator were available from 1975 up to
2001. However, from 1992 until 2005 the import statistics were used for the assessment of the
CMA input. It is assumed that the custom stats together with the transformation factor fCMA lead to a
much more reliable yearly input than the WDI data due to it’s unknown how the WDI data were
assessed. Using the import stats lead to a higher yearly input than the derivation from the penetration rate. For example using the penetration rates in the year 2001 some 750’000 TVs were cumulated in the CMA whereas the deriving from the import statistics adds up to some 930’000 in the
same year (see Appendix 8).
Dominik Zumbuehl
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October 2006
According to Figure 17, some 1’400 tons of TVs should have become obsolete in 2005 assuming
an average lifespan of 15 years but almost no TVs entered the recycling or landfill pathway. Also
for an assumed lifespan of 25 years, still 400 tons of TVs would have become obsolete theoretically. The average lifespan of TVs was investigated by interviewing recyclers in Switzerland and
South Africa. Both South African respondent estimated an average lifespan of 15 years (Bradford,
2006; Scholz, 2006) whereas the Swiss recyclers estimated 10 (Gerig, 2006) and 25 years (Apfel,
2006) respectively as the average lifespan of a TV. According to the ICER report (2004) the lifespan of TVs range from 8.5 years up to 20 years. In this study, two time series were computed
using 15 and 25 years as lifespans.
Again as discussed within the comparison of the CRT monitor flows with the corresponding time
series, there are the following reasons for that difference:
•
The lifespan of 15 and 25 years for a CRT TV is too short. If the lifespan would have been
chosen 30 years (TVs before 1975!) the time series would have fit with the MFA model.
•
Rather than a 30 years lifetime presumably not all the disposal routes had been investigated in the MFA. Thus, the flow of CRT TVs to landfill or to uncontrolled dumps was assessed incompletely. For example, it is very likely that more TVs enter the landfill sites via
the municipal solid waste stream or via the Athlone Refuse Transfer Station during the
night (see section 3.1.9) rather than via the official disposing at Vissershok hazardous landfill site.
•
The lifespan of TVs could be higher than 15 to 25 years because people in the CMA don’t
know where to dispose of the old CRT devices. Maybe they public awareness that e-waste
is hazardous is already existing and thus they know that the municipal solid waste is not
the right channel for their end-of-life equipment.
•
It is also possible that obsolete and broken TVs end up on illegal dumps in areas where the
municipal solid waste is not regularly collected and thus the control by the government is
absent (e.g. in the townships like Kayalitsha or Guguletu). The penetration rate of TVs
even in the townships areas is quite high whereas almost no computers are present. According to Bred Scholz from FreeCom (2006) per 10 capita one TV is present in Kayalitsha
roughly estimated. Hence, it is likely that second or even third-hand TVs enter the townships and are disposed of locally. From the total of 803’110 households in 2004 in Cape
Town some 150’000 were informal dwellings such as shacks in townships or in backyards
(WESGRO, 2005). However, it is not known how many people live in the townships of the
CMA. Thus at this stage it is not possible to estimate the TVs in storage in Kayalitsha and
Guguletu.
Even though at this stage not many obsolete TVs are collected by the recyclers in the CMA or disposed of at landfill sites it is likely that the yearly obsolete CRT TVs in the CMA will increase dramatically in the near future at least until 2020 or 2030.
Dominik Zumbuehl
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October 2006
RESULTS – SCENARIO ANALYSIS
4
SCENARIO ANALYSIS
In section 4.1 the existing best available recycling technologies for the recycling of CRT glass are
presented. Also the local and South African industry was asked to use CRT glass in their processes. These results are also listed in section 4.1. With this knowledge, several recycling scenarios
were defined some within the CMA some including best available technologies overseas. Once the
scenarios had been described, they were assessed towards their sustainability using the MAUT
methodology.
4.1
CRT Recycling technologies
In this section, the current best available technologies (BATs) for the pre-processing and the intrinsic recycling process for CRT glass in Europe are presented as well as the results from the assessment of those companies who were asked if they were able to recycle CRT glass in the CMA
and in South Africa.
The CRT recycling process can principally be divided in the stages shown in Figure 18:
Stripping of TVs and monitors
Plastic casings
PWBs
Aluminium
CRT
Copper
Ferrous metals
Disposal
Electronic
recycling
Separating &
coating
removal
Scrap metal
processing
Crushing
Disposal
Ferrous Metals
Removal of the
coatings &
sorting
Panel glass
Funnel glass
Mixed glass
Use in second application
Figure 18: Possible pathways for the recycling of CRT appliances like monitors and TVs. Coloured boxes
indicate products, white represent are process steps in the CRT recycling.
1. The pre-processing, which includes the stripping (dismantling) of the CRT, screens. The resulting materials are mainly plastics, printed wiring boards (PWBs), metals and the remaining CRT.
The plastics are either disposed of or recycled. Aluminium, copper and ferrous metals are recovered and can be sold to the local scrap dealers to be recycled again. PWBs can be recycled to
recover precious metals like gold, silver, palladium, platinum as well as base metals such as cop-
Dominik Zumbuehl
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October 2006
per, lead, nickel and zinc, bismuth, antimony, etc. Umicore, a state of the art precious metal
smelter in Belgium recovers 17 metals from PWBs (Kerckhoven, 2006).
2. Currently, in South Africa the remaining CRTs are disposed of at (hazardous) landfill sites as
discussed in section 3.1.8. Alternatively, the CRT can either be separated into funnel and screen
glass or they can be crushed depending on the buyer’s requirements. When separating the CRTs
only the screen coating is removed whereas sophisticated crushing devices are able to remove
both the screen and the funnel coating. The crushed cullets can then be sorted to derive panel,
funnel and mixed glass. Some applications also allow mixed, crushed glass that is not sorted. Ferrous metals are also recovered after crushing or separating CRTs (e.g. the rimband and the
shadow mask). Detailed descriptions of the separating and crushing techniques as well as the several applications where the recycled CRT glass can be used are specified in the following section.
The Industry Council for Electronic Equipment Recycling (ICER, 2004) has carried out a project
which was examining potential markets for waste CRT glass in the EU member states. Five potential applications had been investigated, three for screen glass which does not contain any lead and
two for lead-containing funnel glass or mixed glass. The following descriptions of the best available
technologies for the recycling of CRTs correspond partly to the findings in the ICER report and also
to own investigations carried out by literature studies.
4.1.1
Pre-processing – stripping of CRT monitors and TVs
The stripping of monitors and TV sets was studied at a RUAG Components & Immark AG both
Swiss CRT dismantling facilities as well as at Desco Electronic Recyclers in Cape Town. Both the
Swiss and the South African facility use low-tech, manual dismantling techniques using electrical
screwdrivers, grippers and a hammer for the dismantling of the CRT screens.
First, the plastic casing is removed by unscrewing it. To avoid an electric shock, a short circuit of
the anode voltage supply terminal of anode cap attached to cathode ray tube (CRT) should be
performed using an appropriate tool. Without this tool one can just connect a wire to the outer body
of the CRT to then push it under the anode cap and make a good short-circuit (Goldwasser, 2006).
After having removed the casing, the main cord, the cables, the printed wiring boards (PWBs) and
metals such as the ferrous metals, aluminium and the copper coil on the yoke are manually removed and stored in separate units. The remaining part is the CRT with some stickers on it. The
vacuum is being released by breaking the neck glass. The neck glass with the electron gun is
stored and disposed of separately.
Two workers at RUAG can dismantle 50’000 to 80’000 CRTs per year, which results in some 70 to
120 CRTs per day per worker (assuming 350 workdays a year). The employee at Desco can strip
about 75 (average of 50 to 100) monitors per day. Huisman et al. (2004) calculated the time used
to completely dismantle a CRT screen to around 285 seconds which results in 100 CRTs a day
(assuming an 8 hour work day).This value corresponds very well to the values retrieved from
RUAG (70 to 100 CRT devices per day).
Ferrous metals, copper, aluminium and the PWBs are then removed and can be easily recycled as
it is usually economically feasible to process these materials.
The plastic casings of TVs and monitors containing flame-retardants must be disposed of in incineration plants. Some old types of flame-retardants are carcinogenic. Those halogenated flame
retardants form polychlorinated and polybrominated dioxins and furans when burned (Siemers et
al., 1999). Although thermoplasts can be recycled, the recycling of the most of the plastics is difficult because of the many types it occurs and the separation is economically and technically not
feasible. Plastics are usually down cycled or thermal recycled to extract at least the energy
(Siemers and Vest, 1999).
Dominik Zumbuehl
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October 2006
Cables are generally freed by mechanical means of their casings (usually PVC or PE). Only the
copper and other metals contained in cables have prospective uses.
Particularly old TV sets contain wooden pressboards as a casing. It is coated with paints and embedded in plastics and can therefore not be recycled.
4.1.2
Crushing and sorting techniques
For some applications the CRT screens have to be either crushed and / or separated leading to
different products. The crushing of CRTs is carried out by crushing systems which produce cullets
in different sizes and separate the metals and the coatings of the CRT glass. There are several
crushing systems in place and also a mobile solution is available. In this study the sophisticated
crushing system of a Swiss CRT recycler was investigated and a mobile crushing solution which is
provided by a US company.
SwissGlas, Switzerland
SwissGlas a division of Immark AG operates a sophisticated crushing, washing and sorting device
for CRT glass in Switzerland. The site was visited by the author in August 2006. They produce
front, funnel and mixed CRT glass cullets. The products are sold to a European manufacturer for
CRT television glass. There is a growing demand for those high quality recycling cullets (Apfel,
2006).
Process description: the stripped CRT tubes are first crushed, sieved and partly separated into
coarse and fine glass cullets, then the ferrous metals are separated from the glass fraction. The
fluorescent layer on the screen glass as well as the iron oxide coating from the funnel glass have to
be removed because of the manufacturers terms to include recycled CRT glass in their smelting
process. These coatings are mechanically removed by tumbling (German: “trobalisieren”) the cullets. After washing off the dust, containing the removed coatings and some glass dust, the cullets
are dried using electricity. Then the separation step using a detection system to specify the density
of each cullet takes place (funnel glass is denser than front glass due to its lead content). On a
conveyor belt the cullets arrive at detection unit. After blowing out the denser cullets with air jets a
fraction of funnel glass as well as the remaining front and mixed glass is produced. Then the remaining mixed glass is manually separated into pure front glass and mixed glass. The mixed glass
consists of cullets of front glass frit- and funnel glass (see cullet in Figure 19 in the below, middle
picture).
Dominik Zumbuehl
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October 2006
CRT Stock feed
Ferrous metals
Front glass cullets
Funnel glass cullets
Mixed glass: left: front glass, middle:
frit, right: funnel glass.
Waste (glass dust and coatings)
Figure 19: Impressions from the CRT glass recycling at SwissGlas, Switzerland.
Only 0.5% of waste is produced. It contains the fluorescent coating as well as the iron oxide coating and glass dust. This fraction has to be disposed of in an incineration plant. Water is kept in a
closed loop cycle thus no wastewater is produced. Only losses due to evaporation during the drying process occur. This is estimated to be some 100 litres per ton glass produced. The feedstock is
sprinkled to reduce dust emissions outside the plan. The plant uses some 20 to 30 kWh of electricity per ton of glass produced mainly for the drying process.
SwissGlas produces currently approx. 5 tons of CRT cullets per hour. Currently 50% TV and 50%
monitor glass is delivered from Swiss collection and recycling sites. They intend to increase the
production to 7 to 8 tons per hour by the next year with the same facility. Front glass, funnel glass
and mixed glass is produced in the same quantities. The costs for the processing of a ton of glass
are approx. € 220. Around € 100 from the Swiss e-waste management system (SWICO SENS, see
section 1.3) based on the Advanced Recycling Fee (ARF) helps to cover the costs. They employ
currently 11 workers. Eight of them consist of low and semi-skilled workers whereas 3 highly skilled
worker are busy with administrative work.
In addition SwissGlas technology sells their system to other recyclers. The price for the whole system including the intermediation of customers and provider of raw materials is about € 2 Mio. The
separation, washing and sorting unit can be procured for approx € 1Mio, the main expense being
for the separator unit. Without the X-ray device the separation plant can be procured for some €
500’000. This option requires more manual work.
Mobile or Stationary CRT Recycling System
A CRT Processing unit provided by Andela Products Ldt (Hula, 2006) is installed inside a 20 ft.
shipping container and can be used as a mobile CRT processing solution or as a stand alone system. This system comprised with an in-feed conveyor, a CRT breaker, a custom glass conveyor
followed by a cross-belt magnet and custom installed dust collection system. Stripped CRTs can be
fed into the system. A variable speed controller allows the system operator to modify the impactor
processing speeds to produce a larger or smaller glass size distribution depending on the local
glass market specifications. The crushed CRT glass and the metal frames or screens (rimband and
Dominik Zumbuehl
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October 2006
shadow-mask) are separated. The dust collection system includes a high efficiency cartridge dust
collector installed as a stand-alone unit near the CRT recycling container. A negative air pressure
within the container keeps the leaded glass fines or coating flakes that become airborne during the
crushing process. Up to 600 CRTs per hour can be processed by the Andela CRT Recycling system.
The costs for the Andela Stationary Recycling System would amount to around USD 300’000
transport and installation up front included. Around USD 150’000 have to be added to turn this system into a mobile CRT processing system. One semi-skilled and two lower-skilled workers could
operate the system. The system runs with a maximal performance of less than 100 horsepower
that is less than 74.57 kW. To compute the energy used for the processing of one CRT unit the
energy use for one hour (74.57kWh) is divided by the maximum capacity, which is 600 CRTs. This
results in an energy consumption of some 0.124 kWh/CRT. The crushing process is a dry one.
Thus, no water is used.
4.1.3
Separating techniques
Besides the crushing of CRT glass one can also separate the glass without crushing it first. The
advantage is that one does not have to separate cullets but the whole front and funnel glass respectively. Depending on the manufacturers requirements some times it makes more sense to use
separated glass instead of crushed. However when the glass is being prepared for smelting or use
in other products like bricks or foam glass, it usually must be crushed. In this section, the current
separation techniques are described. Most of the techniques are specified in the ICER report
(ICER, 2004). Some of them are marketed and process the glass for CRT manufacturers. In this
report the focus is on the technologies already in use and marketed.
Hot wire technique
A
B
C
D
E
F
Figure 20: Process illustration at RUAG Component Inc., Switzerland
This technology was studied at a Swiss CRT recycling facility (RUAG Components). Since 2001
they run a stripping facility and separate the glass using a semi-automatic hot wire device. After the
dismantling of the monitor or TV the stripped CRT is being installed on a workbench manually. The
Dominik Zumbuehl
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October 2006
following steps are also illustrated in Figure 20. First, the ferrous rim band (implosion protection) is
manually removed A). Then the CRT is scored automatically by scratching with a diamond B). In
the next step a NiChrome ribbon is wrapped around the chink and is then electrically heated C).
The heating takes about a minute and the resulting thermal stress cracks the glass entirely. Then
the cone glass with the frit is manually removed and stored separately D). The remaining front
glass is then freed from its coating by suction cleaning it E). Figure 20 F shows the physical process more schematically.
For the process, three workers are mandatory. RUAG has two separation units in place one for
large and one for small sized screens. The system has a throughput of some 70 CRTs per hour.
The quality of the separated glass is high. According to RUAG (Gerig, 2006) a hot wire system can
be set up by investing some € 300.000. There are second hand systems available for approximately € 150.000 depending on the equipment that comes with the system.
The ICER report (2004) mentions several problems that can occur using the hot wire technology.
One problem is the difficulty to accomplish a clean separation of panel and funnel glass if the wire
is incorrectly placed. Another problem with this approach is that the glass does not always break
along the wire line. This is particularly so when dealing with CRTs of different sizes since larger
TVs have thicker glass. An advantage is that it is a dry process and thus no wastewater is generated. Dust is not produced and the suction removal of the luminescent coating does not allow it to
get airborne. The system does not need much electricity either. The variable costs are relatively
high due to much manual work has to be done using this system. However, in places where labour
costs are low the system could be very cost efficient.
Laser Cutting
This method was investigated by using details of
a laser cutting device manufactured by (Proventia
Automation Oy, 2006), Finland. They provide an
automatic handling and cutting line for CRTs. A
carbon dioxide laser beam cuts the CRT below
the frit and separates the CRT into the funnel
glass with the frit and the remaining front glass. In
addition to the high quality separation and high
capacity, the laser technology also has superior
health and environmental performance. This device can separate up to 75 CRTs per hour. Additionally a cleaning and crushing device is available. Potential problems with the laser approach
include reforming of the glass after the laser Figure 21: Laser cutting process.
Source:http://www.masterautomationgroup.com/
beam has passed through, difficulty in cutting
thick glass, and sharp edges on the separated fractions. It also uses more power than other cutting
techniques and requires significant capital investment (ICER, 2004).
Advantages: high capacity, high quality, low cost / CRT, dry process
Disadvantages: high investment costs , high energy use (Proventia, 2006)
Diamond cutting separation
This uses a wire that is provided with industrial diamonds. The wire diameter is usually very small.
A continuous loop of wire cuts into the glass as the CRT is passed through the cutting plane. The
main problem with this approach is that it is very slow. It also generates dust that needs to be controlled. This research has not identified any companies which are currently using this technique or
Dominik Zumbuehl
48
October 2006
thinking of using it (ICER, 2004). This technology is marketed and provided for instance by MRT
System AB, Sweden.
A semi-automatic system provided by MRT
System AB, Sweden can process up to 45
CRTs per hour. It is capable to handle CRTs
from 14 to 32 inches and is equipped with
glass dust collection and a cyclone for the rare
earth metals. The power consumption is
around 10 kW. No economic data are available
at this stage.
The CRTs are positioned automatically or
manually before cutting depending on the
equipment of the machine. After setting the
index point for the correct longitudinal position, Figure 22: CRT is cut by a diamond cutting device.
the screen is placed into the cutting station Source: http://www.mrtsystem.com/
automatically and front and panel glass are
then separated. The station is enclosed to reduce noise and is ventilated to remove dust. The
products are automatically transported for further processing. Dust and rare earth powders are
collected by a powder cyclone and dust filter. No economic data of this system were available in for
this study.
Water Jet
This technology is commonly used in cutting many different types of material, particularly metal. It
uses a high-pressure spray of water containing abrasive, directed at the surface to be cut. The
water is focused through a single or double nozzle-spraying configuration set at a specific distance
(ICER, 2004). It takes some 30 seconds to separate a CRT. This technology is also marketed and
for instance being transferred to China (Brown, 2006).
Comparison of the above separation techniques
Table 5 shows an overview over the current major CRT separation technologies. As one can see
there is no technology with outstanding properties. They all provide a separation that leads to high
quality of the product and fulfils the requirements of the customers. Most of the devices can be
purchased in different modules making the system more cost effective or dependent of more manual work. In this study no recommendation for a certain technology is given. The market is developing fast and the techniques are getting more and more cost effective. The future costs for e-waste
recycling will decrease as the Institute for Prospective Technological Studies (IPTS) (Europäischer
Wirtschaftsdienst (EUWID), 2006) forecasts.
CRT separating methods
Invest. costs
Variable costs
Capacity
Quality of glass
Wet process
hot wire
Low
Low
ca. 50
High
No
laser cutting
High
Low
ca. 75
High
No
diamond cutting
High
High
ca. 45
High
No
water jet
High
High
High
High
Yes
Table 5: Comparison of several separation technologies towards costs, capacity and quality. Data collected
from (Proventia, 2006) (Gerig, 2006) and (MRT, 2006)
Dominik Zumbuehl
49
October 2006
4.1.4
CRT glass in new CRTs
As there is no CRT manufacturer in South Africa this section is mainly consisting information from
Samsung Corning located in Brandenburg, Germany, which is producing TV CRT glass. All information and numbers are according to an Interview with the technical manager of Samsung Corning.
The European market for the recycling of CRT glass in the manufacturing process of new CRT
glass is currently consolidating. At this stage only Samsung Corning in Germany and ThomsonPolcolor in Poland are processing and manufacturing CRT glass both using significant amounts of
recycled CRT glass. Thomson-Polcolor recently invested in the plant and they will produce at least
10 more years (Apfel, 2006). Also Samsung Corning intends to refurbish their smelting device by
2007 and thus will go on producing CRT glass in Germany for at least 10 more years. Former big
players like SCHOTT, NEC and Philips have ceased to produce CRT glass in Europe. The shift is
towards the production in Asian countries as today 90% of the worldwide CRT production is already located in China (Widmer et al., 2005). There are still some more CRT manufacturers located in Russia and Belarus.
The following company description is according to Samsung Corning, Germany. They currently
produce some 16 Mio. cone and screen glasses per year with a daily output of 260 tons of screen
glass and 160 tons of cone glass. Samsung Corning is engaging 420 employees. They provide
their glasses to customers in Germany, Czech Republic, Poland and Brazil.
Energy and raw materials savings are achieved by using recycled CRT glass. Thus several emissions are reduced. Currently they process up to 40 % recycling CRT glass. With the input of 1 ton
of recycling glass they can save 1.1 tons of raw materials in average. The use of CRT cullets also
reduces dust production but to a less significant part. The losses due to evaporation are not affected by using recycling glass. Incidental dust of 300 tons per year contains large amounts of lead
and can be recycled to a content of 90% internally. Only 10% of the dust has to be disposed of by
selling it to a lead smelter where the lead is being recovered. Thereby the revenues for the dust
cover round about the transport costs.
Samsung Corning mainly takes glass from TV sets and to a lesser extent from computer monitors.
The screen glass of monitors must not be leaded which is the case for the most of the CRTs manufactured after 1990.
The company was not prepared to share the prizes of the raw materials. Thus, it is not possible to
assess the economic benefit of Samsung Corning by using CRT cullets. The costs to produce a ton
of glass include € 240 for the production of cone glass and € 280 for front glass respectively. The
additional costs for Energy and wages are € 40 for screen glass and € 35 for Cone glass. Overall
costs for screen glass are therefore € 320 per ton and € 315 for cone glass respectively.
4.1.5
CRT glass in smelting processes
The following introduction is part from the ICER report (2004) and is not written by the author of this
study:
“Smelting is a high temperature process in which molten metal is separated from the impurities in
metal-bearing material and recovered. Primary smelting extracts metal from ores or concentrates
and secondary smelting recovers metal from scrap material. Most smelting operations use a fluxing material to fuse with impurities and form a liquid slag. This helps in the extraction of the metal.
In smelting operations which use sand as flux there could be potential to substitute CRT glass for
all or some of the required sand, provided that the metals contained in CRT glass, particularly
Dominik Zumbuehl
50
October 2006
lead, are compatible with the process and can be recovered. When considering the use of CRT
glass in smelting it is also essential to ensure that the chemical composition of the resulting slag
(which is where the bulk of the CRT glass will end up) is such that it can be used in new applications, e.g. construction aggregate. The weight-based recycling targets for equipment containing
CRTs set by the WEEE Directive will only be met if the slag and therefore the glass itself can be
recycled for use in other applications.
Metals can be considered in three broad groups — ferrous metals (iron and steel), non-ferrous
metals (such as copper, lead, zinc) and precious metals (such as gold, silver, platinum and palladium). “
Ferrous metal smelting: No sand is used as a flux. Sand is a contaminant in the steel and iron
production. Thus ferrous metal smelting is not suitable for the processing of CRT glass (ICER,
2004).
Primary Lead smelting: Boliden SA in Sweden operates a primary lead smelting facility. Technically, there would be in principle no problem to use the CRT glass in the smelting process. Problems could occur if there is too much of aluminium oxide (Al2O3), chromium would increase the
smelting point (energy use), quicksilver increases the costs for flue gas treatment, antimony increases the costs for refining and silver, antimony, bismuth and tin require refining capacities. Too
much zinc can cause troubles with the slag or the furnace.
Since the lead content in CRT glass (5%) is too low to use it economically in their smelting process,
they even should be paid for taking CRT glass. The economic feasibility depends on the market
price of lead, of the raw materials and the composition of the glass. At this stage, they needed at
least 30% lead in the CRT glass to run the process economically. Including CRT glass would substantially increase the amount of the silica-slag which leads to extra losses (Swartling, 2006).
Zinc smelting: Modern furnaces do not require silica to control slag chemistry and viscosity. Imperial Smelting Furnace (ISF): The metal content of slag is too high to be used in secondary application such as construction aggregate. ISF are not competitive with modern furnaces and are under
the thread of closure. Thus the Zinc Smelting is not applicable for the processing of CRT glass
(ICER, 2004).
Precious metals smelting: Umicore, Belgium: Visits at Umicore in Belgium unveiled that they
cannot include CRT glass in their precious metal recovery plant economically. Although they do
lead recovery, the lead content in CRT glass with an overall content of 5% lead oxide, is not sufficient to run the lead refining economically. Their processes are optimized for precious metal refining. They are rather interested in the supply of materials containing precious metals than in CRT
glass. There is no precious metal smelter which is smelting lead in Europe at this stage
(Kerckhoven, 2006).
Rand Refinery, South Africa is a precious metal smelter operating in the Gauteng Province. They
use lead as a redox additive in the precious metal smelting process that is oxidized to reduce the
precious metals to be reduced again by carbon. Thus, the lead is not used in bulk. Additionally they
use only galena (lead sulphide, PbS) and would not be prepared to use lead oxide. There would be
no economic benefit in using CRT glass. Rand Refinery is only interested in materials containing a
certain amount of precious metals (Gloster, 2006).
Secondary copper / lead smelting process: Fry’s Metal: In South Africa there is currently one
secondary lead smelter based in Germiston near Johannesburg. They process some 60’000 tons
of lead scrap per year and use mainly lead from batteries. Fry’s Metal can only economically use
leaded scrap that has a lead content above some 60%. Approximately one third of the furnace load
ends up in the slag which has to be land filled at the Holfontein H:H landfill site. The costs for the
final disposal on that landfill site are some R500 per ton. A sodium-sulphide slag rather than a
Dominik Zumbuehl
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October 2006
ferro-silicate slag is used in their process thus, there would be no benefit from the silica in the CRT
glass. Latter slag is not leachable but needs more energy in the smelting process. The industry in
South Africa is allowed to dispose of leachable slag whereas in Europe and the US only nonleachable slag can be disposed of at landfill sites. It is economically more feasible to use sodiumsulphide slag and have more disposal costs than changing to the ferro-silicate slag. However, they
are by far not able to use the CRT glass economically due to
a) The use of a sodium-sulphide slag rather than a silica slag
b) Low lead content of CRT glass
c) The increase in slag volume and therefore increasing disposal costs.
NFA: A copper smelter in Cape Town called NFA was not fond of the idea of taking CRTs for the
copper smelting process. The company’s statement was: "Our Processes cannot handle the leaded
glass as our units are not designed for this."
Boliden AB in Sweden operates a secondary copper / lead smelting plant. According to (Swartling,
2006) technically there shouldn’t be any barriers in using leaded glass as a flux in the smelting
process. If more glass (silica) is added to the process, iron oxide and calcium oxide (CaO) have to
be added as well to keep the proportion at a constant level. This generates additional costs. The
furnace has currently no lack of silica and does therefore not rely on more glass input. The lead
extraction of the CRT glass with an average content of some 5% is economically not feasible due
to a relatively high lead content in the slag and mat that have a lead content of some 1-3 % and 68% respectively. A 5% leaded glass would only generate more slag, which has to be disposed of. If
one would only use the funnel glass which has an average lead content of some 22% then it would
eventually be economical feasible to include the glass in the smelting process. However, at this
stage this is not calculated yet.
According to the ICER report (ICER, 2004) most of the secondary copper / lead smelters in Europe
which were asked were not prepared to use the CRT glass in their operation due to mainly the
following reasons:
•
A 5% lead content is to low compared to the lead amount in the remaining slag. The use of
CRT glass would only increase the slag production without substantially extracting the lead
from the glass. If the lead content was substantially higher, many of the smelters say that it
would become eventually economic.
•
The remaining lead concentration in the slag is too high to be reused in a secondary application. Thus, it must be disposed of in hazardous landfill sites. The further processing to
lower the heavy metal content is too expensive.
•
Most of the copper / lead smelters would be mainly interested in the copper from the yoke.
But in most cases the copper has been removed before due to its value by the recycler.
Although many copper / lead smelters stated not to be able to use CRT, glass there is currently
one European company which is already using CRT glass in their smelting process.
Metallo-Chimique in Belgium is currently processing CRT glass in their copper / lead furnace. They
can recover the lead in an economically feasible way. The main advantage is that they recover the
lead almost entirely and the resulting slag is almost free from heavy metals. Hence, it can therefore
be used as a raw material and is marketed as “Metamix”. This process was studied in depth by
Jaco Huisman (2004) and is also described carefully in the ICER report (ICER, 2004). Huisman
assessed the process towards its eco-efficiency using the self developed QWERTY/EE (Huisman,
2003) concept.
Dominik Zumbuehl
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October 2006
The use of CRT glass in a secondary lead smelting processes only make sense economically and
ecologically, if the lead recovery rate is high enough that the slag can be used (sold) again rather
than to be landfilled. From the assessed companies only Metallo-Chimique can provide such a
technology.
4.1.6
CRT glass in bricks
Use of CRT glass in concrete bricks: South Africa has many concrete brick manufacturers and in
the Western Cape, brick manufacturing is a very wide spread industry. Two manufacturers within
the CMA were asked to use the CRT glass in the brick manufacturing process.
Cape Brick: Located in Salt River, Cape Town which is almost in the heart of the CMA Cape Brick
is one of the first masonry manufacturers which has a crushing facility to reduce construction and
demolition waste (C&DW), consisting of mainly reinforced concrete, to recycled crushed aggregate
(RCA). The RCA is used as the main ingredient in all the company's products. 42’000 tons of RCA
are worked up in recycled bricks every year. According to (Gracie, 2006) Cape Brick could also use
the CRT glass in the recycled products. The glass cullets should be supplied in sizes lower than
100 mm in order to be used for the crushing device. It is not known yet if therefore a crushing device would be required. It is namely possible that due to the transportation the glass is crashed to
cullets with sizes below 100mm anyway.
Inca Cape: Located near Somerset West that is in the very eastern end of the CMA, Inca Cape
produces some 25’000 tons of bricks per month. They could avail the CRT glass in the manufacturing of new bricks. They also do not have a crushing facility and should get the cullets in sizes below
7mm. This requires a crushing device, which must be installed separately. They will not be able to
pay for the CRT glass unless it will be delivered in the right amounts and at constant rates.
However, it seems that there are many brick manufacturers who are willing and able to include the
CRT glass in the manufacturing processes. By any means it must be proven that the concentrations of any hazardous substances within the produced bricks are below the regulatory limits and
leaching tests must be carried out to make sure that the environment is protected from hazardous
substances. Also one has to comply with the corresponding occupational health and safety regulations when the CRT glass is crushed.
Use of CRT glass in clay bricks: According to the ICER report, there is substantial volume that
could be used in the manufacturing of clay bricks. This application has particularly good potential to
use large volumes of waste CRT but only panel glass. This shows even greater potential than
waste container glass for reducing the firing temperature and may prove a better fluxing agent because of its higher alkali content and lower melting temperature. One barrier to using CRT glass in
flux in the near term is getting a reliable supply of CRT glass. In order for the brick industry to consider switching to CRT glass, manufacturers need to be assured of a constant supply processed to
the required quality standards. However, in this study the use of CRT glass for clay bricks in South
Africa was not studied.
4.1.7
CRT glass in concrete rubble
Malans Quarries is a company, which produces over 300.000 tons of concrete rubble on a yearly
base. They crush reinforced concrete, concrete bricks and general rubble to produce concrete rubble for road filling purposes. Malans Quarries operates several mobile crushing systems located at
different places in the CMA. This would be an option where the glass and the hazardous substances like lead, barium, cadmium and zinc would be diluted in a way that the resulting concentrations would be far below any regulatory limits. Additionally there are major concerns in terms of
Dominik Zumbuehl
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October 2006
airborne dust while mixing and crushing the CRT glass on site. Hence, this scenario has to be at
least in accordance with the:
Occupational Health and Safety Act, 85 of 1993
Hazardous Chemical Substances Regulations, GN R 1179 of 25 August 1995
Lead Regulations, GN R 236 of 28 February 2002.
This option clearly designs to release hazardous substances in the environment. The South African
National Roads Agency regulates the properties for road building materials within the Guideline for
Road Building Materials, Draft TRH14 (1987). By any means, the blending of CRT glass with concrete rubble has to be in accordance with this regulation.
4.1.8
CRT glass in foam glass
This option was not investigated in this study. But according to the ICER report there is good potential for using CRT panel glass in foam glass. This recycling option has not yet been marketed
(ICER, 2004). It was not investigated if there are any foam glass manufacturers within the CMA.
4.1.9
CRT glass in container glass
Consol Glass is a major player in the world of international glass packaging. It has operations located at Clayville (Midrand), Wadeville (Germiston), Bellville (Cape Town) and Pretoria. Consol
Glass produces container and beverage glass. They were asked to assess the option to include
CRT glass in the manufacturing process. According to Consol Glass’ John Polasek the statements
to this question was as follows:
For the panel glass: “This has a much higher total alkali proportion than our manufactured glass – a
difference of about 11%. Two of the alkali elements in the panel glass are absent from our glasses
– barium oxide and strontium oxide, which together are at a very high level of some 20%. “
For the Funnel (and Neck) glass: “This is lead oxide (PbO) rich. Our furnaces employ electric
boosting for which molybdenum metal conductors are used. Lead readily destroys this metal and
hence leaded glasses can never be used in our glass melting operations. We also employ platinum
coated devices that are immersed in the glass to measure temperature – platinum is also readily
destroyed by lead. We have several times examined the feasibility of using CRT glasses but must
come reluctantly to the same conclusion each time” (Polasek, 2006) .
The main problem with any recycled glass (cullet) that varies grossly from Consol’s standard glass
composition is that they have no facility to intimately mix the cullet with the batch materials. Hence,
the lack of mixing promotes an inhomogeneous final glass and erratic bottle production. If the differences between glass are also gross, as for the panel glass compared to theirs, the cullet would
have to be crushed very finely, in addition to intimate mixing. Even with plate (window) recycled
glass, which is close to their container glass composition, they have to restrict the amount that can
be tolerated to a few percent at most of the total batch weight.
4.1.10 CRT glass in flat glass
Pilkingtons, a South African flat glass manufacturer was asked to assess the use of CRT glass in
the manufacturing process of flat glass. According to Pilkington’s Alex Howitt (2006) the CRT glass
is “so far from the required compositions.” Thus, the flat glass manufacturing seems not to be an
option for the recycling of CRT glass.
Dominik Zumbuehl
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October 2006
4.2
Definition of the CRT recycling scenarios
The investigations of the CRT recycling technologies in section 4.1 unveil that the recycling of CRT
glass can be carried out in many ways. The technologies for the pre-processing are sophisticated
and can be adjusted according to the needs of the customers. Looking at the further processing of
the pre-processed CRT glass only a few applications seem to be feasible at this stage. The following table gives an overview over the assessed applications.
Application for CRT glass
technically feasible
CRT glass manufacturing
Secondary copper / lead smelters
Brick manufacturing
Concrete rubbel manufacturing
Precious metals smelting
Primary lead smelting
CRT glass in foam glass
Ferrous metal smelting
Zinc smelting
CRT in container glass
CRT in flat glass
Europe
Yes
Yes
Yes
?
Yes
Yes
Yes
No
No
No
?
South Africa
No
Yes
Yes
Yes
Yes
No
?
No
No
No
No
economically feasible
Europe
Yes
Yes
?
?
No
No
?
?
South Africa
No
?
?
No
?
-
Table 6: Technical and economical feasibility of the CRT recycling technologies assessed in this study
According to Table 6 the following applications for the recycling of CRT glass were included in the
scenarios that were further assessed in the MAUT assessment presented in section 4.2.
•
CRT to CRT glass manufacturing at Samsung Corning in Germany
•
Secondary copper / lead smelting at Metallo-Chimique, Belgium
•
Use of CRT glass in concrete Bricks at Cape Brick, Cape Town
•
Use of CRT glass in concrete rubble manufacturing at Malans Quarries, Cape Town
Eight scenarios have been defined (see Table 7) according to the above conclusions. Note: Scenario 2 (Lead mine) was not investigated in the previous chapter. This scearnio was added due to
an idea of a local IT professional. The landfilling of the stripped CRT screen as it is currently practiced in the CMA was taken as the baseline scenario to compare it with recycling scenarios which
are combinations of the current best available technology (BAT) in Europe as well as of local solutions within the industry or alternative storage options for the CRTs. As the stripping of the monitors
and TVs already occurs in the CMA, the starting point for any of the scenarios is the stripped CRT.
The scenarios are described qualitatively and assessed quantitatively in the MAUT assessment
presented in section 4.3.
No.
Name
Key steps, description
Locality
0
Landfill
Transport to Vissershok landfill site from Desco Electronic Recyclers
in Paarl
CMA
1
Lead mine
Transport to the “Black Mountain” lead mine in Agganeys, Northern
Cape. Indefinite storage in the mine, no processing
2
Concrete rubble
Transport within Cape Town, use in concrete rubble production as
raw material, chemical analysis of product
Dominik Zumbuehl
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Agganey, Northern Cape
CMA
October 2006
3
RCA brick
Transport within Cape Town, use in RCA brick production as raw
material, chemical analysis of product
CMA
3a
Concrete brick
Transport within Cape Town, use in concrete brick production as raw
material, chemical analysis of product
CMA
3b
RCA brick with
Andela CRT processing system
Transport within Cape Town, crushing in mobile crushing unit, use
cullets in RCA brick production as raw material, chemical analysis of
product
CMA
4
CRT manufacturing
Crushing, washing and separating in Cape Town using SwissGlas
technology, transport to CRT manufacturer, use as raw material
CMA, Germany
5
Lead recovery
Transport to Metallo-Chimique, use as flux in copper / lead smelting
2
process and for lead recovery, slag used in “Metamix ” for building
materials
Belgium
1
1) RCA
2) Metamix
Recycled Crushed Aggregate
Byproduct of smelting process at Metallo-Chimique, sold to the building industry
Table 7: Overview of all scenarios described in this section and used for the MAUT assessment
Dominik Zumbuehl
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October 2006
RESULTS – APPLICATION OF THE MAUT
4.3
Application of the MAUT
In this section, the eight scenarios specified in the previous chapter will be assessed towards their
sustainability using the MAUT. First, some adjustments of the attributes defined in section 2.3.1
have to be carried out due to several reasons explained in the following.
4.3.1
Adjustment of the attributes
In Appendix 16 the results of the stakeholders’ weights are shown. 18 persons filled in the questionnaire (see Appendix 15) for the weighting of the attributes. The group consisted of 4 consulting
engineers and scientists, 4 waste managers, a supplier of IT equipment, 3 technicians and engineers involved in a computer refurbishment project (not locals), 5 governmental representatives
and 3 representatives from an environmental NGO. A lead smelter (industry) also filled in the questionnaire but did not participate in the workshop.
The weighting procedure at the workshop was carried out before the completion of the MAUT assessment. It was recognized that some of the attributes, weighted during the workshop, were not
measurable or were redundant. Thus, some adjustments to derive the final attribute set for the
MAUT assessment had to be carried out. Table 8 shows the corresponding adjustments as well as
the stakeholders’ weights and the weights used in the MAUT assessment (see also Table 2 for the
scale of the weights).
Attributes defined for the stakeholders’
weighting
stakeholders’
weight
Attribute applied in the MAUT
Weight used
in MAUT
Economic
Scael: 0..4
High profit
2.06
redundant ( considered in the Net costs)
Low operational costs for processing
2.94
Net costs
2.94
Low capital costs
2.47
Low capital costs
2.47
3.00
Increased potential for local economic
growth
3.00
Eco-indicator 99 points
12.72
3.47
Scael: 0..4
-
Environmental
3.06
3.24
3.18
Little toxic emissions
3.25
Minimum of waste volume to landfill
3.47
3.47
redundant Æ considered in Eco-Indicator
99 value
Low toxicity of waste to landfill
-
Social
Working hours for low-skilled/semi-skilled
in the CMA
Working hours for highly skilled in the
CMA
Creation of jobs for the previously unemployed in Cape Town
3.22
Creation of highly skilled jobs in Cape Town
2.22
1.50
Working hours outside South Africa
1.50
3.22
Low health and safety impacts
3.22
3.22
2.22
Table 8: Adjustment of the set of attributes presented at the regional workshop to derive the final set of attributes for the MAUT assessment.
The “High profit” attribute was not considered in the MAUT as it is already considered in the “Net
costs” which are calculated from the overall costs and the revenues of a scenario and thus are
equal to the operational costs. The most striking adjustment is the aggregation of the environmental attributes such as “Low use of electricity”, “Low fuel use for transport”, “Low use of freshwa-
Dominik Zumbuehl
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October 2006
ter”, “Little toxic emissions”. The reason for the aggregation is the use of the Eco-indicator 99 as
the environmental Impact assessment rather than the above attributes. As the attributes are aggregated but not considered redundant, the stakeholders’ values were added to derive the weight
used for the weighing of the Eco-indicator 99 value. “Low toxicity of waste to landfill” is redundant
and is represented in the Eco-indicator 99. All social attributes were used in the MAUT assessment. Only the names were changed slightly but still meaning the same.
Note: The supporting calculations for all scenarios are specified in Appendix 13. All input data and
the corresponding sources as well as the corresponding relative errors used in the calculations are
listed in Appendix 12. Particularly currency exchange rates, fuel prices, fuel use of vehicles, wages
of workers and freight considerations with all type of considered vehicles can be found. These figures were used to derive the values in the following scenario assessments. In addition, Appendix
14 shows the detailed figures of the environmental impact assessment i.e. the list of the Ecoindicator 99 and Impact 2002+ values.
4.3.2
Scenario 0 – Landfill
The current practice in the CMA to recycle CRT TVs and computer monitors is to strip them and
sell the valuable parts either to the scrap metal market or to the electronic recycler that processes
the material or sells it to the next customer. Most of the CRTs are brought to the hazardous landfill
site in Vissershok. An unknown amount is disposed of at the non-hazardous landfill sites within the
municipal solid waste stream (MSW). The only landfill site in the CMA which can handle hazardous
waste and therefore CRTs is the Vissershok H:H landfill site located some 30 km in the north of
Cape Town’s City centre. The Vissershok landfill site is protected using a geocomposite liner where
an HDPE (high density polyethylene) geomembrane is used in conjunction with clay layers
(Entech, 2006) is shown in Figure 23. For this scenario only the landfilling in the hazardous landfill
site was considered rather than the disposal in the municipal solid waste landfills as this is the formal way of disposing CRTs at this stage. This leads to an underestimation of the environmental
impacts of the current practice where CRTs also are disposed of at municipal solid waste landfill
sites.
Lining of the Vissershok H:H landfill site
Figure 23: Lining of the Vissershok landfill site in the year 2000. source: (Entech, 2006)
http://www.entech.co.za/Projects/Waste/vissershok.html
Dominik Zumbuehl
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October 2006
Ferrous metals
Scrap metal
market
Aluminium
Computer
monitors
&
TV sets
Copper
PWBs 1
Electronic scrap
recycler
Plastic casings
Landfill
CRT
1) PWBs: Printed wiring boards
Figure 24: Current baseline recycling scenario of TVs and computer Monitors carried out by an electronic
recycler in the CMA.
Today the CRTs are stripped at Desco Electronic Recyclers near Paarl that is some 50 km outside
the CMA. The transport distance to the Vissershok landfill site is estimated to be some 60 km
(round trip). Usually a trailer with a capacity of 1000 kg is loaded with CRTs and transported to the
Vissershok landfill site. Figure 25 shows schematically the parameters investigated for the assessment in the MAUT. All values used for the assessment are listed in Table 9.
energy costs work
1 kg CRT
costs
work
Hazardous
Landfill
Transportation
emissions
emissions
Figure 25: Scenario 0: landfilling of CRTs at Vissershok landfill site
Economics: The costs for the 60 km round trip from Kraaifontein to the Vissershok landfill site
amount to $ 0.0083 /kg CRT. Labour costs including the time use for loading of the trailer and driving to the landfill site amounts to $ 0.0083 $/kg CRT. The disposal fee for a ton of e-waste is ZAR
200 (Novella, 2006) per ton which is $ 0.0278 $/kg CRT. The net costs for scenario 0 add up to $
0.044 $/kg CRT. No investment costs are required for the landfilling scenario and no increased
potential for local economic growth is expected since no other industry is engaged by this scenario
(value = 0).
Environment: The environmental impact of scenario 0 comprises the transport and the long-term
effects of the landfilling. For the calculation of the Eco-indicator 99 points, a module for a VAN (<
3.5 tons) from the ecoinvent database was taken. A new dataset for the composition of CRTs (see
Table 18) was generated in ecoinvent in order to model the long-term impacts of such waste in
hazardous landfill sites. The eco-indicator for the landfilling process amounts to 0.0064. Waste
volume to landfill of remaining waste is maximal (1kg/kg CRT).
Social: For the loading and unloading and the round trip to the landfill site in Vissershok it takes 3
hours of semi-skilled work including the loading/unloading and driving to the landfill site. This results in 0.003 hours/kg CRT glass. No additional jobs for highly skilled employees are created. No
Dominik Zumbuehl
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October 2006
additional jobs outside South Africa are created. A low health and safety impact is expected due to
the breaking of the glass during loading, unloading and the transport to the landfill site. By breaking
the tubes the coatings from the front glass could get airborne.
Economics
Transport costs
Fuel use
Distance (round trip)
Fuel price
Load trailer
Labour costs
Time used
Wage semi-skilled worker
Load trailer
Disposal costs
Disposal fee
Load trailer
Net costs
Investment costs
Environment
Total Eco-indicator 99 points
Transport, VAN 3.5t, CH
Landfilling CRT glass on hazardous landfill site
Social
Work for low-skilled / semi-skilled in the CMA
Time used (loading & driving)
Load trailer
Working hours for hihgly skilled in the CMA
Unit
Value
Rel. error
Max. value
Min. value
$/kg CRT
l/100km
km
$/l
kg
$/kg CRT
h
$/h
kg
$/kg CRT
$ / ton
kg CRT
$/kg CRT
$
-
0.0083
15
60
0.92
1'000
0.0083
2
4.17
1'000
0.0278
27.8
1'000
0.0444
0
0
70%
25%
10%
10%
25%
125%
50%
50%
25%
50%
25%
25%
68%
+/- 0.1
0.0111
0.0054
0.0136
0.0031
0.0347
0.0208
0.0594
0
0.1
0.0293
0
-0.1
EI' 99 points
EI' 99 points
EI' 99 points
kg/ kg CRT
0.0064
0.0051
0.0013
1
25%
25%
25%
-
0.0072
0.0056
1
1
h/kg CRT
h
kg
h/kg CRT
h/kg CRT
-
0.003
3
1'000
0
0
0.5
60%
50%
25%
+/- 0.1
0.0039
0.0021
0
0
0.6
0
0
0.4
Table 9: Overview of the MAUT results from scenario 0
4.3.3
Scenario 1 - Lead mine
The Black Mountain lead mine is located 10 km west of Aggeneys, Namaqualand District, Northern
Cape Province that is some 560 km outside the CMA. It is the only lead mine in South Africa with
copper, silver and zinc also mined there (Department of Minerals and Energy (DME), 2006). It is
owned and operated by Anglo American. To get rid of the CRT glass without wasting landfill volume and to save the disposal costs for the landfilling, one could store the CRT glass in the Black
Mountain lead mine.
The high-grade ore body from Broken Hill has been exploited and a new lower grade ore body
(Swartberg) is being exploited now. Copper, lead and zinc metal occur as sulphides in the ore. In
addition, ore from stopes in the upper levels of the Broken Hill ore body is considerably tarnished
(oxidized). Besides those elements, also bismuth, cadmium and cobalt can be found in the ore.
(Williams et al., 2001). The fact that some ore bodies are no longer in use and that lead sulphide,
lead oxide and even cadmium is present, the disposal of CRT glass in that mine seems to be environmentally safe although not proven yet. In this study, it is assumed that the lead mine is not connected to any groundwater flows and that therefore possible leaching from metals of the CRT glass
is not supposed to cause any problems.
Legislation: In South Africa, annual Environmental Management Programme Report (EMPR) performance reports have to be submitted to the Department of Minerals and Energy (DME) by the
mine operators. The Mineral and Petroleum Resources Development Act, No. 28 of 2002 (DME,
Dominik Zumbuehl
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October 2006
2002) defines the managing of mining waste, residues, stockpiles, dams etc. After the closure of a
mine comprehensive rehabilitation has to be carried out and the monitoring of disposal sites and
dams has to be warranted. The mining operator is responsible for any damage to the environment
during and after the mining operation. The disposal of waste not produced within the mine is not
regulated within this legislation. Such an application must be allowed by the Department of Water
Affairs and Forestry (DWAF) and the Department of Environmental Affairs and Tourism (DEAT) in
cooperation with the DME (Dittke, 2006). Figure 26 shows schematically the parameters investigated for the assessment in the MAUT. All values used for the assessment are listed in Table 10.
energy costs work
1 kg CRT
costs
Transportation
work
Storage in lead mine
emissions
emissions
Figure 26: Scenario 1: Storage of CRTs in the Black Mountain lead mine
Economics: The roundtrip to the Black Mountain lead mine in Agganeys takes some 15 hours for
a “super-link” truck. The fix costs for the truck are derived from the costs from Cape Town to Johannesburg. They add up to ZAR 6100. This amounts to $ 0.0170 /kg CRT wage for the driver
included. Loading and unloading takes 2 low-skilled workers 3 hours (own estimation). This results
in $ 0.0003 /kg CRT. The net costs amount to $ 0.0173 /kg CRT. No investing costs are required
for the lead mine scenario. Little potential for local economic growth is expected as only the transport industry can profit from this scenario (value = 0.25).
Environment: The Eco-indicator 99 considering the transport and the definite storage of CRT
glass in the mine amounts to 0.0184. Basically the CRT glass is disposed of safe in a lead and
cadmium environment and therefore no additional short term impacts from the disposal in the lead
mine can be expected. Nevertheless, the long-term impact of the landfilling was added considering
the worst case scenario. There is no waste volume to landfill.
Social: For the transportation and the storage in the lead mine, some additional jobs can be created. Assuming that for the loading and unloading of a 50 tons-truck 2 workers are engaged for 3
hours each and a driver needs some 15 hours (1120 km) for the round trip. This results in a job
creation for the previously unemployed and semi-skilled potential of 0.0004 jobs /kg CRT. No jobs
for the highly skilled will be created. No jobs are created outside South Africa. A medium health
and safety impact is expected due to the breaking of the glass during loading, unloading and the
long transport to the lead mine. By breaking the tubes the coatings from the front glass could get
airborne.
Economics
Transport costs
Price for "Super-Link" truck
Load “Super-Link” truck
Labour costs (loading and unloading and storage only)
Time used
Wage of low-skilled worker
Dominik Zumbuehl
Unit
Value
Rel. error
Max. value
Min. value
$/kg CRT
$
kg CRT
$/kg CRT
h
$/h
0.0170
848
50'000
0.0003
6
2.08
75%
50%
25%
100%
50%
25%
0.0233
0.0106
0.0004
0.0001
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October 2006
Net costs
Investment costs
Environment
Transport, lorry 40t, CH
Social
Working hours for low-skilled / semi-skilled in the CMA
kg CRT
$/kg CRT
$
-
50'000
0.0173
0
0.25
25%
75%
+/- 0.1
EI' 99 points
EI' 99 points
EI' 99 points
kg/ kg CRT
0.0184
0.0171
0.0013
0
h/kg CRT
h
kg
h/kg CRT
h/kg CRT
-
0.00042
21
50'000
0
0
0.5
0.0237
0
0.35
0.0107
0
0.15
25%
25%
25%
-
0.0207
0.0161
0
0
75%
50%
25%
+/- 0.1
0.00058
0.00026
0
0
0.6
0
0
0.4
Table 10:Overview of the MAUT results from scenario 1
4.3.4
Scenario 2 - Concrete Rubble
In this sceanario the CRTs are collected from a central dismantling site which is located at one of
the drop-off sites in the CMA. A 40 feet shipping container would be transported to the Malans
Quarries that would result in a transport distance of some 30 km both ways. Malans Quarries is a
company which produces over 300’000 tons of concrete rubble on a yearly base. They are located
in Bellville, which is within the CMA and some 15 km outside Cape Town city centre. They crush
reinforced concrete, concrete bricks and general rubble to produce concrete rubble for road filling
purposes. Malans Quarries operates several mobile crushing systems located at different places in
the CMA. This scenario envisages that the CRTs are mixed with the raw material and are then
crushed to use them in the road foundation. This would be an option where the glass and the hazardous substances like lead, barium, cadmium and zinc would be diluted in a way that the resulting
concentrations would be far below any regulatory limits. Additionally there are major concerns in
terms of airborne dust while mixing and crushing the CRT glass on site. Hence, this scenario has to
be at least in accordance with the:
Occupational Health and Safety Act, 85 of 1993
Hazardous Chemical Substances Regulations, GN R 1179 of 25 August 1995
Lead Regulations, GN R 236 of 28 February 2002.
These regulations determine the prescriptive limits for hazardous substances (e.g. lead, zinc, cadmium (sulphide), yttrium, etc.).
This option clearly designs to release hazardous substances in the environment. The South African
National Roads Agency regulates the properties for road building materials within the Guideline for
Road Building Materials, Draft TRH14 (1987). By any means, the blending of CRT glass with concrete rubble has to be in accordance with this regulation. Figure 27 shows schematically the parameters investigated for the assessment in the MAUT. All values used for the assessment are
listed in Table 11.
Dominik Zumbuehl
62
October 2006
energy
1 kg CRT
costs
work
Transportation
raw material
savings costs work
Crushing and
use in concrete rubble
emissions
emissions
Road filling
emissions
Figure 27: Scenario 2: Use of CRTs in concrete rubble manufacturing
Economics: A 40 feet container transport within CMA costs ZAR 1260 (Faragher, 2006). Thus,
transport costs amount to $ 0.0075 /kg CRT for the cartage within Cape Town. Additional cost
would arise from the loading and unloading of the shipping container as well as from the controlled
mixing of the CRTs into the raw material. The loading of a container engages a worker for 3 hours.
One worker is engaged for 2 hours to allocate the CRT glass to achieve the corresponding dilution.
The labour costs amount to $ 0.0013 /kg CRT. The product would have to be proven on the chemical composition regularly. Per container load, one series of chemical analysis of the product and
the supervising of the occupational exposure limits during the crushing of the CRT glass have to be
carried out to be sure to adhere the regulatory limits. These additional costs are roughly estimated
to be some $642 per container load assuming five chemical samplings, which leads to $ 0.0273/kg
CRT. The net costs add up to $ 0.0362 /kg CRT. At this stage, Malans Quarries is not prepared to
pay anything for the CRT glass. Thus, no revenues for the providing of CRT glass can be expected.
No investing is required for the concrete rubble scenario (value = 0). Using CRT glass in new products could lead to a stimulation of the recycling industry to include more recyclable materials in the
manufacturing of their products. Using the CRT glass in the concrete rubble manufacturing requires
the transport- and building industry and stimulates the use of recycling materials in the production
rather then raw materials. Hence a medium potential for local economic growth is expected (value
= 0.5).
Environment: The Eco-indicator 99 value is -0.0035 taking into account both the impacts (losses)
of the transport and the benefits (gains) from the raw material savings. The CRT glass replaces a
mixture of bricks, concrete and reinforced concrete. It is assumed that the hazardous waste is released into the environment when leaching from the concrete rubble when used in road foundation.
The hazardous substances are not enclosed in a solid product. They are rather present in small
particles with a large surface making them able to react with the environment. Since at this stage
no data is available from the ecoinvent database (version 1.2.) for the impact of this material it was
assumed that this impact equals at least the impact of the landfilling of a CRT in a hazardous landfill site. Waste volume to landfill of remaining waste is supposed to be 0.
Social: The loading of a container engages a worker for 3 hours and a driver for 1 hour for the
round trip. 1 worker is engaged for 2 hours to distribute the CRT glass on site to achieve the corresponding dilution. A highly skilled employee would be busy with the chemical analysis of the produced concrete rubble for 2 hours per container load. This results in a job creation potential of
0.00026 hours/kg CRT for low-skilled/semi-skilled and 0.00009 hours/kg CRT for highly skilled
respectively. No jobs will be created outside South Africa. Health and safety impacts are consid-
Dominik Zumbuehl
63
October 2006
ered to be high due to the ability of the coatings from the front glass to get airborne while loading,
unloading and distributing as well as when crushed to be mixed into the concrete rubble.
Economics
Transport costs
Transportation costs within CMA
Load container
Labour costs low-skilled
Time used for low-skilled worker (loading, mixing)
Load container
Labour costs highly skilled
Time used for highly skilled work (chemical tests)
Wage of highly skilled worker
Additional costs
Chemical anlysis
Load container
Net costs
Investment costs
Environment
building, brick, to sorting plant
building, concrete, not reinforced, to sorting plant
building, reinforced concrete, to sorting plant
Social
Working hours for low-skilled / semi-skilled in the
CMA
Time used
Load container
Time used
Load container
Unit
Value
Rel. error
Max. value
Min. value
$/kg CRT
$
kg CRT
$/kg CRT
h
$/h
kg CRT
$/kg CRT
h
$/h
$/kg CRT
$
kg CRT
$/kg CRT
$
-
0.0075
175
23'500
0.0004
5
2.08
23500
0.0009
2
11.12
0.0273
642
23500
0.0362
0
0.5
20%
10%
10%
85%
50%
25%
10%
75%
25%
50%
35%
25%
10%
34%
0.0082
0.0067
0.0006
0.0003
0.0013
0.0006
0.0321
0.0226
0.0422
0.0301
+/- 0.1
0.6
0.4
-0.0035
0.0007
-0.0016
-0.0016
-0.0022
0.0013
0
figures
53%
25%
25%
25%
25%
25%
-
-0.0045
-0.0026
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
kg/ kg CRT
unit
0
0
h/kg CRT
h
kg
h/kg CRT
h
kg
h/kg CRT
-
0.00026
6
23'500
0.00009
2
23'500
0
0.75
60%
50%
10%
35%
25%
10%
+/- 0.1
0.00033
0.00018
0.00010
0.00007
0
0.85
0
0.65
4.3.5
Scenario 3 - Recycled crushed aggregate (RCA) bricks
This scenario foresees that the CRTs would be collected from a central dismantling site, which
would be located at one of the drop-off sites in the CMA. A 40 feet shipping container would be
transported to the Cape Brick located in Salt River which would result in a transport distance of
some 30 km both ways. Cape Brick is one of the first masonry manufacturers which has a crushing
facility installed to reduce construction and demolition waste (C&DW), consisting of mainly reinforced concrete, to recycled crushed aggregate (RCA). The RCA is used as the main ingredient in
all the company's products. 42’000 tons of RCA are used in recycled bricks every year. Cape Brick
could use the CRT glass in the recycled products. The glass would have to be delivered in cullets
below 100 mm size, which eventually requires a crushing facility or manual crushing. Note: In this
scenario, the pre-crushing was not included. It is included in scenario 3b.
The raw material input apparently passes through four different reduction processes before being
finally reused. The primary crusher is outside and reduces the building rubble to some 200 mm
fragments. Using a normal front loader, the material is then moved inside and passed through two
Dominik Zumbuehl
64
October 2006
more crushers, before being finally sized and shaped for their manufacturing process (Newson,
2006).
The internal operations produce a lot of dust. Air samples are regularly taken and analyzed to confirm air quality and levels of airborne hazards. Again as in scenario 2, it must be proven that the
concentrations of any hazardous substances within the produced bricks are below the regulatory
limits and that leaching tests have to be carried out to make sure that the environment is protected
from hazardous substances. In addition, the Occupational Health and Safety Act, 85 of 1993 with
the corresponding regulations have to be considered due to the exposure of the workers to airborne hazardous particles during the crushing process. Figure 28 shows schematically the parameters investigated for the assessment in the MAUT. All values used for the assessment are listed in
Table 12.
energy
1 kg CRT
costs
work
Raw
material Energy
savings savings work
Transportation
Crushing &
manufacturing bricks
emissions
emissions
Brick use
emissions
Figure 28: Scenario 3: Use of CRT glass in the manufacturing of recycled crushed aggregate (RCA) bricks
Economics: A 40 feet container transport within the CMA costs ZAR 1260 (Kühne & Nagel, Cape
Town). Thus the transport costs amount to $ 0.0075 /kg CRT for the cartage within Cape Town.
Additional cost would arise from the loading and unloading of the shipping container as well as
from the controlled mixing of the CRTs into the raw material. The loading of a container engages a
worker for 3 hours. One worker is engaged for 2 hours to allocate the CRT glass to achieve the
corresponding dilution. The labour costs amount to $ 0.0013 /kg CRT. The product would have to
be proven on the chemical composition regularly. Per container load, one series of chemical analysis of the product and the supervising of the occupational exposure limits during the crushing of the
CRT glass, have to be carried out to be sure to adhere the regulatory limits. These additional costs
are roughly estimated to be some $642 per container load assuming five chemical samplings of the
bricks produced of which leads to $ 0.0273 /kg CRT. The net costs add up to $ 0.0362 /kg CRT.
Cape Brick would not be prepared to pay anything for the CRT glass. No investing is required for
this scenario (value = 0). Only little increased potential for local economic growth is expected due
to the same reasons as described in scenario 2.
Environment: The Eco-indicator 99 value is -0.005, which includes both the impacts of the transport and the benefits from the raw material savings. The CRT glass replaces recycled, reinforced
concrete. It is assumed that the hazardous waste is released into the environment when leaching
from the bricks in the remote future but in a highly diluted way. This impact is set equal to the impact of the landfilling of a CRT in a hazardous landfill site. Waste volume to landfill of remaining
waste is supposed to be 0.
Social: Through the transportation process, some additional jobs can be created. The loading of a
container takes one worker engaged for 3 hours and a driver for 1 hour from the site where the
Dominik Zumbuehl
65
October 2006
CRTs are dismantled to Salt River and back. One worker is engaged for 2 hours for unloading and
distributing the CRT glass for the corresponding dilution. Then someone will be busy with the
chemical analysis of the product. This results in a job creation potential of 0.00026 for low skilled
and 0.00009 hours/kg CRT for highly skilled respectively. No additional jobs will be created outside
South Africa. Health and safety impacts are considered to be high due to the same reasons explained in Scenario 2 (value = 0.75).
Economics
Transport costs
Transportation costs within CMA
Load container
Labour costs
Load container
Additional costs
Chemical anlysis
Load container
Net costs
Investment costs
Environment
building, reinforced concrete, to sorting plant, CH
Social
Time used
Load container
Time used
Load container
Unit
Value
Rel. error
Max. value
Min. value
$/kg CRT
$
kg CRT
$/kg CRT
h
$/h
kg CRT
$/kg CRT
h
$/h
$/kg CRT
$
kg CRT
20%
10%
10%
60%
25%
25%
10%
75%
25%
50%
35%
25%
10%
33%
0.0082
0.0067
0.0006
0.0003
0.0013
0.0006
0.0321
0.0226
0.0422
0.0302
$
-
0.0075
175
23'500
0.0004
5
2.08
23'500
0.0009
2
11.12
0.0273
642
23'500
0.0362
0
0.5
+/- 0.1
0.6
0.4
EI' 99 points
EI' 99 points
EI' 99 points
kg/ kg CRT
-0.0049
0.0005
-0.0054
0
30%
25%
25%
-
-0.0056
-0.0041
0
0
h/kg CRT
h
kg
h/kg CRT
h
kg
h/kg CRT
-
0.00026
6
23'500
0.00009
2
23500
0
0.75
35%
25%
10%
35%
25%
10%
+/- 0.1
0.00030
0.00021
0.00010
0.00007
0
0.85
0
0.65
4.3.6
Scenario 3a - Concrete bricks
This scenario comprises the use of CRT glass in conventional concrete bricks rather than in the
RCA bricks described in section 0. This scenario is almost equal to scenario 3. The net costs and
the social figures are equal to those in scenario 3. Only the environmental attributes differ as instead of recycled material sand and gravel are replaced by the CRT glass.
Unit
Environment
Savings of sand, at mine, CH
Savings of gravel, crushed, at mine, CH
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
kg/ kg CRT
Value
Rel. error
Max. value
Min. value
0.0003
0.0005
-0.0001
-0.0001
0
65%
25%
25%
25%
-
0.0004
0.0006
-0.0001
-0.0001
0
0.0002
0.0004
-0.0001
-0.0001
0
Table 13: Results of the environmental assessment of scenario 3a
Dominik Zumbuehl
66
October 2006
4.3.7
Scenario 3b - Andela CRT processing system
In S3 and S3a, the use of a pre-crushing device to size the glass cullets according to the needs of
the concrete rubble and brick manufacturers is uncertain. Nevertheless, it was assessed in this
study. It is intended to use the Andela CRT recycling unit specified in section 4.1.2. All figures used
in the following calculations are according to the specifications provided by Andela Products, Ltd.
(Hula, 2006).
Economics: In addition to the net costs of S3, the operating costs for the crushing device have to
be added. Three low-skilled workers are supposed to be used for the operation of the crusher. The
maximum capacity of the crushing device is applied and for the weight of CRTs, the average of the
monitor and TV CRTs weight was calculated. This adds up to slightly higher net costs of 0.0.0369
$/kg CRT compared to 0.0362 $/kg CRT in scenario 3. A mobile version of the Andela CRT recycling system costs around USD 450’000 including the shipping and installation up front (Hula,
2006). Since the crushing device would be purchased as a complete system, the local industry
would not benefit by producing components for the system. Contrary the system would be operated
and maintained locally. Thus a quite high potential for local economic growth is expected (value =
0.75) but less than in S4.
Environment: In addition to the Eco-indicator 99 of S3 the impacts from the crushing device has to
be added. Since the crushing device only uses electricity this impacts was added. The crusher runs
with a maximal performance of less than 100 horsepower, which is less than 74.57 kW. The energy
used for the processing of 1 kg CRT is 0.008 kWh. The eco-indicator 99 is therefore 0.0000359
points higher which is -0.00484 compared to -0.00487. This difference is negligible. Minimum of
waste volume to landfill is not altered by the use of the crusher (value = 0).
Social: Low-skilled and semi-skilled jobs in the CMA: In addition to the 0.00026h/kg CRT used in
S3 0.00033 h/kg CRT are generated using the CRT crushing device. Adding up the resulting working hours lead to a total working hour of 0.00059 h/kg CRT. Note: A throughput of 600 CRTs per
hour seems to be very high and could be substantially lower in practice. Highly skilled jobs in the
CMA and jobs outside South Africa: Neither additional working hours for the highly skilled within the
CMA nor any jobs outside South Africa are generated using a crushing device. Low health and
safety impacts: Health and safety impacts will increase from 0.75 to 1 since the crushing of CRT
glass is assumed to release dust from the screen coatings and the CRT glass though a dust collection system is installed (see Fehler! Verweisquelle konnte nicht gefunden werden.).
Economics
Transport costs
Transportation costs within the CMA
Load container
Labour costs
Load container
Additional costs
Chemical analysis
Load container
Cost for the crushing of CRT glass
Number of employees
Capacity of crusher
Average weight of CRT
Dominik Zumbuehl
Unit
Value
Rel. error
Max. value
Min. value
$/kg CRT
$
kg CRT
$/kg CRT
h
$/h
kg CRT
$/kg CRT
h
$/h
$/kg CRT
$
kg CRT
$/kg CRT
$/h
CRTs/h
kg
0.0075
175
23'500
0.0004
5
2.08
23'500
0.0009
2
11.12
0.0273
642
23'500
0.0007
3
2.08
600
15.3
20%
10%
10%
60%
25%
25%
10%
75%
25%
50%
35%
25%
10%
95%
25%
25%
25%
20%
0.0082
0.0067
0.0006
0.0003
0.0013
0.0006
0.0321
0.0226
0.0010
0.0004
67
October 2006
Net costs
Investment costs
Environment
Transport, lorry 32t
Electricity, medium voltage, at grid
reinforced concrete, to sorting plant
Social
CMA
Working hours for loading and transport
Time used
Load container
Working hours for CRT crushing
Number of employees
Capacity of crusher
Time used
Load container
$/kgCRT
$
-
0.0369
450’000
0.75
35%
25%
+/- 0.1
0.0432
506250
0.85
0.0305
393750
0.65
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
kg/ kg CRT
-0.0048
0.0005
0.0000
-0.0054
0
30%
25%
25%
25%
-
-0.0056
-0.0041
0
0
h/kg CRT
h/kg CRT
h
kg
h/kg CRT
CRTs/h
kg
h/kg CRT
h
kg
h/kg CRT
-
0.00058
0.00026
6
23'500
0.00033
3
600
15.3
0.00009
2
23'500
0
1
69%
35%
25%
10%
95%
50%
25%
20%
35%
25%
10%
+/- 0.1
0.00078
0.00030
0.00038
0.00021
0.00048
0.00017
0.00010
0.00007
0
1.1
0
0.9
Table 14: Overview of the MAUT results from scenario 3b with the Andela CRT crushing device
4.3.8
Scenario 4 - CRT manufacturing
At this stage no CRT glass manufacturer is present in South Africa (Coetzee, 2006). The option to
pre-process the CRTs in South Africa and send the glass cullets to Germany for CRT manufacturing was investigated. The CRTs need to be separated into panel and front glass to fulfil the requirements of the CRT manufacturers. This scenario envisage to install a pre-processing facility in
the CMA for the crushing, removal of the screen and funnel coating, washing and separation of the
CRT glass. Subsequently the glass cullets will be shipped it in a 40 feet container to Hamburg
where it will be unloaded and transported to the Siemens Corning CRT manufacturing plant in
Brandenburg. Figure 29 indicates the involved processes parameters.
Siemens Corning processes recycling CRT glass for the production of front and funnel glass for the
manufacturing of TV tubes. They also take CRT glass from computer monitors but the front glass
must not be contaminated with lead oxide. Note: At this stage, Siemens Corning does not accept
mixed waste glass. Nevertheless, for the calculations in this scenario the mixed waste glass is included in the manufacturing process.
Dominik Zumbuehl
68
October 2006
energy
costs
work
energy costs work water
energy costs
SG: 0,295 kg
1 kg CRT
Crushing, cleaning
& separating
Transportation
revenues
emissions
CG: 0,295 kg
MG: 0,295 kg
Material
Savings
work
Energy
savings
SG: 0.295 kg
Transportation to
CRT manufacturer
CG: 0.295 kg
MG: 0.295 kg
CRT manufacturing
Ferrous Metals
emissions
emissions revenues
waste
Lead dust
SG = Screen Glass
Hazardous landfill
Metal scrap dealer
FG = Funnel Glass
To lead smelter
MG = Mixed Glass
Figure 29: Scenario : CRT manufacturing in Germany
Economics: The net costs were calculated taking into account the costs for transportation and preprocessing, minus the market price paid from the CRT manufacturers for the CRT glass cullets.
This includes also the revenues of the ferrous metals of the CRTs sold to the scrap dealers. These
costs would arise in the South African recycling system. The total transportation costs were provided by an offer from a transportation company Kühne & Nagel (see Appendix 17). They and add
up to $ 0.2125 /kg CRT. The costs for the pre-processing plant were calculated using data provided
by SwissGlas (Apfel, 2006). SwissGlas operates a crushing, coating removal and separating plant
in Switzerland. The costs for the pre-processing amount to $ 0.128 /kg CRT (including the treatment of 0.5 w% slag at an incineration plant). The same facility operated in CMA was estimated
could be run for only $ 0.058 /kg CRT as the labour costs are approximately nine times lower. The
revenues by selling the glass cullets to the German CRT glass manufacturer are $ -0.136 /kg CRT
(average revenues from Samsung Corning and Thomson in Poland). The net costs amount to $
0.1341 /kg CRT. The investment costs for such a plant would be some $ 1.28 Mio but could be
lower considering more manual work and less sophisticated technology. There is a significant potential for local economic growth considering the operation and maintenance of the separation
plant. The construction of the plant’s components would also be partly carried out in the CMA
(value = 1).
Environment: CRT glass separation uses some 0.025 kWh of electricity per kg CRT glass. Freshwater consumption is considered to be around 0.1 l/ kg CRT and is kept in a closed loop cycle.
Only evaporation due to the drying process of the cullets occurs. No wastewater is produced. 0.5%
of the processed material (coatings and glass dust) is disposed of at an incineration plant. In South
Africa the produced waste is supposed to be disposed of at a hazardous landfill site.
CRT manufacturing: using 1 kg CRT glass as a stock feed in the CRT manufacturing saves 1.14 kg
of raw materials listed in Appendix 11. Additionally about 0.006 m3/kg CRT of natural gas and
0.014 m3/kg CRT of oxygen can be saved using recycled CRT glass. No electricity can be saved.
The overall Eco-indicator 99 is -0.042. 0.5% waste is generated resulting in 0.005kg/kgCRT waste
volume to landfill.
Social: The transport and pre-processing operations create jobs inside and outside South Africa.
For the loading and transporting of a 40 feet container to the pre-processing plant some 4 hours
are estimated. The recycling plant runs with eight low-skilled employees and 3 highly skilled. 5 tons
of CRT glass is produced per hour. This results in 0.0018 h/kg CRT for low skilled and 0.0006 h/kg
CRT for highly skilled in CMA. From the pre-processing plant, the container has to be transported
to the harbour, which takes 1 hour and the processing of one container at the harbour in Cape
Town again 0.1 hour. The shipping crew consists of 6 low skilled workers and 6 highly skilled offi-
Dominik Zumbuehl
69
October 2006
cers (Gsponer, 2006). The freighter carries 2’500 40 feet containers and it takes 283 hours from
Cape Town to Hamburg. In Hamburg only 0.1 hours is used for the unloading of one container.
Then it takes some 5 hours to transport the container to Samsung Corning in Brandenburg. This
results in working hours of 0.00027h/kg CRT outside South Africa. Medium health and safety impacts are expected in this scenario due to a sophisticated handling of the glass at the separation
plant including sprinklers for dust reduction at the crusher. Only the loading transportation process
to the separation plant can lead to airborne particles from the screen coatings (value = 0.5).
Unit
Economics
Transport costs
Container to Hamburg
Container to Samsung Corning
Load container
Crushing and separating costs
Net processing costs
Net labour costs
Number of employees
Wage of semi-skilled worker
Production volume
Revenue from CRT manufacturer
Average revenue at Thomson
Average revenue at Samsung Corning
Net costs
Investment costs
Environment
Transport, to separation plant
Water
hazardous waste, to underground deposit
Transport to port CH
Transport, transoceanic freight ship
Transport, to Samsung Corning
Natural gas, burned in industrial furnace >100kw
Oxygen, liquid, at plant
Silica sand, at plant
Feldspar, at plant
Soda, powder, at plant
Potassiumloride, as k2o, at regional storehouse
Lead, at regional storage
Dolomite, at plant
Potassium nitrate, as n, at regional storehouse
Sodium antimonate
Barium carbonate
Strontium carbonate
Limestone, milled, loose, at plant
Zirconium silicate
Titanium dioxide, production mix, at plant
Ceroxide
Zinc for coating, at regional storage
Social
CMA
Time used for pre-processing
Time used for loading and transport
Time used for shipping
Production volume
Load container
Dominik Zumbuehl
Value
Rel. error
Max. value
Min. value
$/kg CRT
$
$
$
kg CRT
$/kg CRT
$/h
$/h
$/h
kg/h
$/kg CRT
$/kg CRT
$/kg CRT
$/kg CRT
$
-
0.2125
175
3'712
1'107
23'500
0.0575
642
401
11
4.17
5'000
-0.136
-0.137
-0.135
0.1341
1'284'700
1
20%
10%
10%
10%
10%
37%
10%
10%
25%
50%
10%
20%
10%
10%
68%
25%
+/- 0.1
0.2338
0.1913
0.0682
0.0469
-0.1496
-0.1224
0.1796
1'445'288
1.1
0.0886
1'124'113
0.9
EI ‘99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
EI' 99 points
kg/ kg CRT
-0.042
0.00049
0.00011
0.00000
0.00029
0.00033
0.01520
0.00978
-0.00056
-0.00017
-0.00039
-0.00018
-0.00158
-0.00157
-0.05450
-0.00302
-0.00592
?
?
?
-0.00001
?
-0.00042
?
-0.00027
0.005
56%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
25%
50%
-0.0542
0.0006
0.0001
0.0000
0.0003
0.0004
0.0171
0.0110
-0.0006
-0.0002
-0.0004
-0.0002
-0.0018
-0.0018
-0.0613
-0.0034
-0.0067
0
0
0
0.0000
0
-0.0005
0
-0.0003
0.0063
-0.0306
0.0004
0.0001
0.0000
0.0003
0.0003
0.0133
0.0086
-0.0005
-0.0001
-0.0003
-0.0002
-0.0014
-0.0014
-0.0477
-0.0026
-0.0052
0
0
0
0.0000
0
-0.0004
0
-0.0002
0.0038
0.0018
8
4
0.1
5'000
23'500
38%
25%
25%
100%
25%
10%
0.0021
0.0014
h/kg CRT
h
h
h
kg CRT
kg
70
October 2006
Production volume
Distance Cape Town - Hamburg
Ships complement (crew)
Speed of freighter
Number of 40 feet containers on board
Time used from Hamburg to Samsung Corning
Load container
h/kg CRT
h
kg CRT
h/kg CRT
km
km/h
h
kg CRT
-
0.0006
3
5000
0.00027
11882
12
42
2'500
5
23'500
0.5
50%
25%
25%
55%
10%
25%
10%
10%
50%
10%
+/- 0.1
0.0008
0.0005
0.0003
0.0002
0.6
0.4
4.3.9
Scenario 5 - Lead recovery
As in section 4.1.5 described there is no secondary copper / lead smelter within South Africa who is
capable to process the CRT glass. Thus, scenario 5 comprises the trans-oceanic freighting of the
stripped CRTs from a collection point in the CMA to Beerse in Belgium to Metallo-Chimique. Figure
30 indicates the transport and the lead recovery process as well as the use of the remaining slag.
energy
1 kg CRT
costs
work
raw
material energy
costs savings savings
Lead recovery at
Metallo
Transportation
emissions
emissions
Lead
“Metamix” in
building industry
emissions
Figure 30: Scenario 5: lead recovery at Metallo-Chimique
Economics: Transport costs are estimated to be some $ 0.180 /kg CRT for the cartage to the port
of Cape Town and the freighting costs as well as the unloading and handling costs (customs, port
costs etc., see Appendix 17) for a 40 feet container calculated by Kuehne+Nagel (Faragher, 2006).
Metallo-Chimique charges € 40 for a ton of stripped CRTs (€ 140 for whole monitors and TVs)
which contributes with $ 0.0514 /kg CRT. Thus, the net costs for the scenario 5 consist of the total
transport costs and the charges at Metallo-Chimique. This adds up to net costs of $ 0.232 /kg CRT.
No additional investing is required as Metallo-Chimique already uses CRT glass in their smelting
processes. No additional technology or industry is involved in this scenario thus no increased potential for local economic growth is expected.
Environment: Estimates of Jaco Huisman (2005) unveiled that 1kg of CRT glass can save some
0.5 kg of silica in the lead smelting process. Metallo-Chimique agreed to use this rough estimation
for the assessment of the environmental impact though they were not prepared to name any exact
figures. The main environmental benefit results from the lead extraction. The CRT glass replaces
lead scrap and not primary lead. Anyway, lead is recovered and replaces a certain amount of primary lead on the market. This amount of lead does not have to be produced from raw material
anymore. Thus, the recovering lead from CRT glass was considered in this study. No other raw
material than sand and lead can be saved using CRT glass. Additionally energy can be saved by
using CRT glass but again no figures were available. As the use of glass instead of sand lowers
Dominik Zumbuehl
71
October 2006
the melting temperature in any silica-based smelting operation it was roughly assumed that the
amounts of energy savings are as much as in scenario 4. However, the impacts from the energysavings compared to the impact of the lead recovery are almost negligible. The main environmental
gain (which is 75 times higher than the effect of the assumed energy savings) results form the extraction of the lead. Lead is almost completely recovered. The remaining slag is marketed as
“Metamix”. It contains the remaining hazardous substances from the CRT glass but in very low
concentrations. The “Metamix” is sold to the building industry. In this study, the remaining Metamix
is considered to have at least the environmental impacts of the landfilling process of CRT glass
without the lead. Thus, a dataset for the disposal of CRT glass without the lead was generated in
the ecoinvent database. The overall Eco-indicator 99 is -0.038. The Waste volume to landfill is 0.
Social: The loading of the container takes 3 hours. Transportation to the Cape Town port takes 1
hour and the processing of one container at the harbour in Cape Town again 0.1 hour. The shipping crew consists of six low-skilled workers and 6 highly skilled officers. The freighter carries 2500
40 feet containers and it takes the freighter 272 hours from Cape Town to Antwerp. In Antwerp only
0.1 hours is used for the unloading of one container (Gsponer, 2006). Then it takes 1 hour to transport the container to Metallo-Chimique. The working hours for low-skilled ad semi-skilled workers in
the CMA amounts to 0.00017 h/kg CRT. No highly skilled work is carried out within South Africa.
The working hours outside South Africa amount to 0.00004 h/kg CRT. Minimal health and safety
impacts are expected in this scenario due to a sophisticated handling of the glass at the lead recovery plant. Only the loading and unloading process of the container can lead to airborne hazardous particles (value = 0.25).
Economics
Transport costs
Container to Antwerp
Container to Metallo-Chimique
Load container
Additional Charges at Metallo-Chimique
Net costs
Investment costs
Environment
Transoceanic freight ship, Cape Town to Antwerp
Transport, lorry 32t, Antwerp to Metallo-Chimique
Silica Sand, at plant
Natural gas, burned in industrial furnace >100kw
Lead recovery
Disposal, Pb-free CRT slag, to residual material landfill
Social
Time used (loading and transport)
Time used (shipping)
Load container
Working hours outside South Africa freighting
Distance Cape Town - Antwerp
Speed of freighter
Working hours outside South Africa in Belgium
Dominik Zumbuehl
Unit
Value
Rel. error
Max. value
Min. value
$/kg CRT
$
$
$
kg CRT
$/kg CRT
$/kg CRT
$
-
0.1802
175
3712
347
23'500
0.0514
0.2315
0
0
20%
10%
10%
10%
10%
5%
17%
0.1982
0.1621
0.0527
0.2508
0.0501
0.2122
+/- 0.1
0.1
-0.1
EI ‘99 points
EI ‘99 points
EI ‘99 points
EI ‘99 points
EI ‘99 points
EI ‘99 points
EI ‘99 points
EI ‘99 points
EI ‘99 points
kg/ kg CRT
unit
h/kg CRT
h
h
kg
h/kg CRT
h/kg CRT
h/kg CRT
km
km/h
-
-0.0381
0.0005
0.0146
0.0016
-0.0007
-0.0006
-0.0002
-0.0545
0.0011
0
figures
0.00017
4
0.1
23'500
0
0.00010
0.00006
11423
12
42
2'500
0.00004
48%
25%
25%
25%
25%
25%
25%
25%
25%
-
-0.0473
-0.0289
0
0
36%
25%
50%
10%
93%
80%
10%
25%
10%
25%
110%
0.0002
0.0001
0
0.00014
0
0.00005
0.00007
0.00002
72
October 2006
Time used from Antwerp to Metallo-Chimique
Load container
h
kg CRT
-
1
23'500
0.25
100%
10%
+/- 0.1
0.35
0.15
Dominik Zumbuehl
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October 2006
4.4
Summary of results and discussion
This section presents the aggregated utilities from the above MAUT assessment. Following the
results from the weighted and unweighted utilities of the recycling scenarios are presented and
compared to each other. Subsequently the utilities and the values of the several attributes are discussed in a more detailed way.
4.4.1
Comparison of the unweighted and weighted utilities
Figure 31 shows the normalized results from the MAUT assessment for the scenarios described in
the previous section. Both the utilities containing the stakeholders’ weights as well as the unweighted utilities are indicated. The black lines represent the error bars derived from the error
propagation.
The CRT manufacturing scenario (S4) achieves the highest utility in both the stakeholder weighted
as well as in the unweighted case. The second best scenario is the lead recovery scenario (S5) at
least in the weighted case. The scenarios S2, S3, S3a and S3b reach almost the same utilities as
the landfilling and the lead mine scenarios (S0 and S1) reach the lowest ranking. Looking at the
unweighted case S4 clearly ranks out all other scenarios. The utility from the lead recovery scenario (S5) is almost as low as the utility from the landfilling and lead mine scenario.
Considering the variance derived from the error propagation, S4 is significantly above all other
scenarios though for the unweighted case only. In the weighted case, the utility of S4 is not significantly higher than of S5. However, it is significantly higher (and therefore robust) compared to the
scenarios S0, S1, S2, S3, 3a and S3b. On the other hand, the lead mine-scenario (S1) scores significantly below all other scenarios but scenario 0 in the weighted case. In the unweighted case no
other scenario than S4 is robust compared to any of the scenarios.
Total utility unweighted, normalized
Total utility weighted, normalized
1.200
1.000
0.800
0.600
0.400
0.200
0.000
S0
Landfill
S1
Lead mine
S2
Concrete
Rubble
S3
RCA brick
S3a
Concrete brick
S3b
Brick with
crusher
S4
CRT manuf.
S5
Lead recovery
Figure 31: Unweighted MAUT results and the results with the stakeholders’ weight. The black lines indicate
the total errors of the utilities.
Figure 32 shows the MAUT utility of every single attribute assessed for both the weighted and the
unweighted utilities. The following comparison intends to show the differences in the relative contributions of an attribute’s utility to the aggregated utility of a specific scenario. Note: The scales of
the two diagrams are different but that does not affect the comparison since the relative contributions are compared rather than the absolute values. In this comparison, the stakeholders’ weighting
Dominik Zumbuehl
74
October 2006
is used for the explanation of the differences of the unweighted and the weighted utilities. The
stakeholders’ weights are shown in Appendix 16. In addition, the MAUT values used in Figure 32
are shown in Appendix 20.
In general the environmental utility contributes much less to the overall utility in the unweighted
case than it does in the weighted case. This is mainly due to the fact that the Eco-indicator 99
weight consists of the sum of all the weights from the attributes “Low use of electricity”, “Low fuel
use for transport”, “Low use of freshwater” and “Little toxic emissions” as explained in section 0.
Thus, the weighted Eco-indicator 99 contributes much more to the overall utility than it does in the
unweighted case.
The attributes “Working hours for highly skilled in the CMA” and “Working hours outside South Africa” reach also a smaller relative utility in the weighted case than in the unweighted. These two
attributes were weighted significantly lower compared to the other attributes. The utilities from the
rest of the attributes show a similar pattern of the distribution in the unweighted and the weighted
case respectively as the weighting of these attributes do not differ much from each other.
MAUT utility unweightedsfdf
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
MAUT utility weightedsadf
0.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
S0
Landfill
S1
Lead mine
S2
Concrete
Rubble
S3
RCA brick
S3a
Concrete brick
S3b
Brick with
crusher
S4
CRT manuf.
S5
Lead recovery
High eco-indicator 99
Investment costs
Low net costs
Figure 32: Comparison of the weighted and unweighted MAUT utilities. Note the scale of the diagrams is different.
4.4.2
Weighted utilities
Following the weighted utilities are discussed in a more detailed way. The discussion refers to the
weighted utilities shown in Figure 32. First, the outcome of each scenario is discussed briefly to
locate the main contributors to the utility of a scenario. Subsequently the attributes are discussed in
depth.
Dominik Zumbuehl
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October 2006
S0: the main contribution to the landfilling scenario (S0) stems from the large social utility. This is
due to the transportation to the landfill site, which is carried out with only a 1000kg trailer whereas
for all other scenarios, transport weights form 23.5 tons and 50 tons respectively were chosen.
Thus, the working hours per kg CRT are quite high in the landfilling scenario. The utility of the
“Minimum of waste volume to landfill” attribute is zero. Thus, the environmental utility is very low
compared to the other scenarios.
S1: Though it is a relatively cost effective option, it ranks as worst solution mainly due to a bad
environmental score. The low environmental score stems mainly from the long transport distance
with the lorry to the lead mine. The utilities from the social attributes are relatively low, compared to
S0 and S4.
S2, S3 and S3a: These scenarios achieve almost equal utilities due to the same results in the economic and social assessment. The main contribution to the net costs is the chemical analysis of the
product, which accounts for almost 80% of the total costs. They only differ slightly in the environmental score as each of the scenarios saves different raw materials. The social utility is the lowest
due to a very short transport distance and because of low working hours generated. In addition, the
health and safety impacts are estimated to be high because of the exposure of the workers to airborne hazards during the mixing and crushing process. Thus, the utility from the “Low health and
safety” attribute is low.
S3b: In this scenario, the crusher has to be purchased and thus the utility for the “Low investment
costs” is lower than in S3. On the other hand, the “Increased potential for local economic growth”
utility is higher also because of the crusher. S4 with high investment costs and increased potential
for local economic growth shows the same pattern. The net costs are not significantly higher due to
low costs for the operation of the crusher. Again, the main cost driver is the chemical test of the
product. A few more working hours for the low skilled are generated in S3b. The health and safety
utility is the lowest of all scenarios because hazardous dust can get airborne during two crushing
processes (Andela crusher and brick manufacturing).
S4: The CRT manufacturing scenario comes off as winner in this study. The main contribution
stems from the environmental utility although the long transport distance from Cape Town to Germany. The main contributor to the environmental utility is the recovery of the lead. Without the lead
recovery, the environmental utility would be even lower than the in the landfilling scenario (S0). In
addition, the social utility is maximal due to the working hours for low skilled and highly skilled in
the CMA by the operation of the CRT-separation plant as well as the working hours generated by
the transoceanic transport. This scenario leads to high operational and investment costs. Thus, the
economic utility is low.
S5: As second best solution ranks the lead recovery scenario at Metallo-Chimique. As in S4, this
ranking is mainly due to the environmental gain due to the lead recovery. Social utility is higher
than S2, S3, S3a and S3b. That is because of the working hours caused by the shipping of the
CRT glass to Europe. The economic utility is the lowest due to the highest net costs and due to no
potential for local economic growth.
4.4.3
Comparison of the attributes
Following the results from the several attributes will be discussed in depth.
Net costs: The landfilling scenario shows a high net cost utility with net costs of $ 0.044 /kg CRT.
This is slightly higher than the net cost from the scenarios S2, S3, S3a and S3b. Very high net
costs result in S4 and S5 that are three times and five times higher respectively than the landfilling
net costs. S5 has no utility due to the maximum net costs with $ 0.232 /kg CRT.
Dominik Zumbuehl
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October 2006
Low capital costs: Only S4 and S3b require any investment. Thus, this utility is 0 and 0.054 respectively. All other scenarios reach utilities, which are almost equal. Again as explained in section
4.1.2, in S4 the investment costs could be halved by omitting the X-ray separation device whilst
more manual work is needed. Thus, in addition to the lowered investing costs more working hours
for the low skilled could be generated. However, this would raise the net costs on the other hand.
Increased potential for local economic growth: This attribute was the most difficult and uncertain in the MAUT assessment. Nevertheless, it was assessed considering additional industries
involved in a certain scenario. The highest potential for local economic growth was allocated to the
S4 scenario because a new recycling plant would be installed in the CMA and that the plant would
be constructed, operated and maintained by local companies. In addition, S3b reaches a high utility
due to the operation and maintenance of the Andela CRT processing system. A middle potential is
allocated to the scenarios S2, S3 and S3a. It is assumed that the local recycling industry could be
stimulated because of using recyclables in their processes and new processes could be established. Only little potential for local economic growth was allocated to S1, which includes long
transport distances. This could contribute to the local transport industry. No local economic growth
is expected for the landfilling and the lead recovery scenario since they do not stimulate the local
industry.
Eco-indicator 99: The environmental inventory was assessed by using inventory data from the
ecoinvent database (ecoinvent Centre, 2005). Additionally to the existing modules for transport,
energy use, raw materials etc., a landfilling module for CRT glass was generated to assess the
impacts of CRT glass disposed of on landfill sites. This was completed by modifying an existing
hazardous landfill module including the chemical composition of a CRT (see Table 18). A second,
similar module was generated using the same chemical composition but the lead (only for the impacts of the “Metamix” in scenario 5). Naturally, the landfilling module was used for the landfilling
scenario. Although the CRT glass is diluted, it has at least the long-term impact of the landfilling.
Thus for all the scenarios where CRT glass is intended to be released in the environment the landfilling module was included. The landfill module was applied in Scenario 0, 1, 2 and 5. Note: It must
be clearly indicated that for scenarios 3, 3a and 3b no landfilling impact was added assuming that
the CRT glass is inertly bound in the brick matrix. Hence, no release of any hazardous substances
in the environment is expected. In this scenario, the fate of the brick and therefore the impacts of
the bricks after their end of life are not included. However, the impact of the landfilling of CRT glass
is 0.0013. The landfilling of CRT glass without lead (see Metamix in S5) reaches 0.0011 EI ‘99
points. This is only a small difference.
Appendix 14 shows that in general the impact of long transportation processes is very high (0.0171
EI ‘99 points for the lead mine scenario) compared to the majority of other impacts. Contrary the
environmental gain of processes, including lead recovery (S4 and S5) is even higher. In fact, the
lead recovery in S4 and S5 leads to an almost four times higher environmental gain (-0.054 EI ‘99
points) than the corresponding impact of the long transport distances. In general, this results in a
good environmental utility of scenarios either showing short transport distances or a lead recovery
process involved.
Accordingly it is clear that the lead mine scenario with a) a long transport distance and b) no lead
recovery, has no environmental utility. Even the landfilling scenario has a higher utility than the lead
mine scenario due to a much shorter transport distance.
The Eco-indicator 99 score was also compared with the results form the impact 2002+ assessment
shown in Figure 33. Looking at the left diagram, the impact on the human toxicity is very large compared to all the other impacts. This is mainly due to the landfilling module present in S0, S1, S2 and
S5. The main contribution to the human toxicity of the CRT glass compounds is the antimony
(SbO3). It contributes with almost 100% to the human toxicity (Hischier, 2006). As the human toxic-
Dominik Zumbuehl
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October 2006
ity outnumbers all other effects in the Impact 2002+ assessment, the effect of the human toxicity
was excluded for the comparison of the Impact 2002+ with the Eco-indicator 99 results. The effects
without the human toxicity are shown in Figure 33 on the right hand side. The resulting impacts and
benefits follow the same pattern as calculated with Eco-indicator 99. S4 and S5 reach the highest
environmental gains as S1 and S0 clearly have the highest environmental losses.
Thus from an environmental point of view all the options including the release of CRT glass in the
environment (S0, S1, S2 and S5) are clearly not environmental sound and should therefore not be
taken into account.
climate change
terrestrial acid. & nutr.
human toxicity
climate change
terrestrial acid. & nutr.
aquatic ecotoxicity
terrestrial ecotoxicity
aquatic ecotoxicity
terrestrial ecotoxicity
4.E-05
3.E-05
3.E-04
Impact 2002+
Impact 2002+
2.E-05
2.E-04
1.E-04
1.E-05
0.E+00
-1.E-05
S0
S1
S2
S3 S3a S3b S4
S5
-2.E-05
4.E-05
-3.E-05
-6.E-05
S0
S1
S2
S3 S3a S3b S4
S5
-4.E-05
Figure 33: Impact 2002+; left: with human toxicity impact, right without human toxicity impact
Minimum of waste volume to landfill: This attribute was assessed separately because it was
chosen because of the Polokwane Declaration on Waste Management (Government of South Africa, 2001) and the fact that the landfills in the CMA are about to be full in the next few years
(Essop, 2005). S0 and to a minor degree also S4 (only 0.5 w%) intend to landfill any waste. Hence,
the utility is zero for S0 where the whole CRT is disposed of on the landfill site. In all other scenarios, the utility is equal to each other.
Social attributes – general considerations: The social indicators are mainly based upon working
hours generated in a certain scenario. Thus, it was essential to include every single job step in a
scenario. The steps included in the scenarios were loading and unloading of the CRT glass, transportation and in some cases the pre-processing of the CRT glass. Most of the working hours are
based on estimates. Reliable data were available only for already existing processes such as the
time used for the landfilling scenario (S0), the working hours in the separation plant (S4) and the
trans-oceanic shipping (S4 and S5).
Additionally the distinction between the working hours generated for low- and semi-skilled workers
and those for the highly skilled workers had to be carried out. It was assumed that in general the
loading of CRT glass, the transportation is being carried out by low-and semi-skilled workers. Jobs
such as the chemical analysis in S2, S3, S3a and S3b and partly the CRT separation in S4 are
supposed to be carried out by highly skilled workers.
Low-skilled and semi-skilled jobs in the CMA: S0 reaches the highest score since the transport
process is carried out with only a 1000 kg trailer rather than a shipping container or a 50 t lorry.
This leads to 0.003 h / kg CRT. In addition, a high score achieves S4, which includes the operation
Dominik Zumbuehl
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October 2006
of the CRT separation plant in the CMA. In the separation plant, eight low-skilled and semi-skilled
workers are engaged. Note: these figures are valid for the separation plant currently installed in
Switzerland were labour costs are much higher than in South Africa. Thus, it is likely that the operation in SA requires more manual work rather than the use of all the sophisticated technology currently installed. All other scenarios only reach relatively low scores due to mainly short transport
distances or the lack of any pre-processing steps for the CRT glass.
Highly skilled jobs in the CMA: The majority of the highly skilled jobs are generated due to the
operation of the CRT separation plant in S4, which engages three highly skilled workers. The working hours calculated for the separation plant are based on the current production volume of 5 tons
per hour. As the recycling plant intends to extend the production up to 8 tons per hour presumably,
the working hours per kg CRT will decrease slightly. It is not known if proportionally more workers
will be engaged by increasing the production. Also in S2, S3, S3a and S3b some working hours for
highly skilled in the CMA are needed due to the chemical analysis of the products.
Jobs outside South Africa: Only S4 and S5 generate jobs outside South Africa. The transoceanic transport contributes with 0.00006 h/kg CRT for both S4 and S5. The transportation from
the port in Hamburg to Samsung Corning in S4 was estimated to take 5 hours, which leads to
0.00021 h/kg CRT that amounts to more than three times the fraction of the trans-oceanic transport. In S5, only 1 hour is used for the transportation from the port in Antwerp to Metallo-Chimique.
Thus, S4 reach the highest utility.
Low health and safety impacts: This attribute was estimated semi-quantitatively only. A scenario
was supposed to have health and safety impacts when dust from the CRT glass or the screen
glass coating gets airborne. This depends mainly on the kind of the transportation and on the processing of the glass.
A small utility is reached by S2, S3 and S3a, the smallest by S3b. These scenarios include the
crushing of the CRTs with the crushing devices already installed, where lots of dust gets airborne
and thus the workers are exposed to hazardous substances. In addition, S3b includes the crushing
using the Andela CRT processing system, which leads to more airborne dust. S0 has also a small
utility due to the use of an open trailer that also leads to airborne particles. S1 too reaches only a
small utility due to the loading of the “super-link” truck which can cause much more breaking of the
glass and thus more dusts from the coating could get airborne during the loading and unloading of
the truck compared to a shipping container. A middle score reaches S4 due to the secure handling
at the separation plant using sprinklers at the crushing device to reduce airborne particles. Additionally after the removing of the screen coating, no hazards can get airborne while sending the
CRT glass to Europe. S5 reach the highest score due to the glass is enclosed in the shipping container from the CMA until Metallo-Chimique where protective measures for the workers and sprinkling systems are set in place to reduce airborne hazards.
The CRT manufacturing scenario (S4) clearly dominates the ranking in this assessment whereas
the lead recovery scenario (S5) is second best but not robust compared to S2, S3, S3a and S3b.
The landfilling scenario (S0) is second last and the lead mine scenario (S1) clearly is last and robust.
4.4.4
Recycling fees
Though S4 is considered the best solution for the recycling of CRT glass in the CMA, it has a bad
economic utility. Following the economics of S4 are compared with the costs of a similar European
CRT recycling alternative. The net costs for S4 amount to $ 0.134 /kg CRT. Huisman (Huisman,
2003) (see p. 176) calculated the integral costs (= net costs) for the recycling of a 17” CRT monitor
in Belgium. Taking only the costs for the transport, the costs for the shredding and separation and
Dominik Zumbuehl
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October 2006
the costs for the glass furnace (to make it comparable with S4) this results in € 0.81 + € 0.27 + €
0.48 = € 1.56 per CRT monitor. With the weight of 14.7 kg per monitor, this results in € 0.106 /kg
CRT that is $ 0.134 /kg CRT.
Coincidentally the costs for the CRT to CRT recycling from the stripped monitor is exact the
amount of the net costs calculated in S4. However, this comparison did not intend to show that the
costs of S4 are equal to the costs calculated by Huisman. The intention was to show that the costs
for the recycling with S4 are in the same order of magnitude as they are in Europe.
Using $ 0.134 /kg CRT as the net costs for S4 this adds up to $ 1.19 for a monitor CRT and $ 2.9 $
per TV CRT (see Table 4 for the weights of CRTs). Note: The costs for the dismantling at Desco
Electronic Recyclers are not included. As they are already dismantling the monitors at Desco economically, it is assumed that no additional costs will arise. Thus, it is estimated that the ARF for a
CRT monitor is around $ 1.2 and $ 3 for a CRT TV respectively. These costs could be paid either
by an ARF or at the time of disposal.
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October 2006
CONCLUSIONS
5
CONCLUSIONS
MFA and time series
The mass flow assessment of CRT screens unveiled that there is still a growing stockpile of computer monitors and TVs in the CMA mainly at consumption level. Though the sales figures of CRT
computer monitors will decrease dramatically within the next 3 years, there will be an increasing
amount of obsolete CRT monitors at least until the year 2020. The lifetime of a CRT computer
monitor in the CMA is according to the comparison of the MFA with the corresponding time series
17 years.
For CRT TVs no sales forecast was carried out due to a very unstable market and diverging statements of the market leaders to the fate of CRT TVs. Taking into account that at this stage only a
very small amount of TVs enter the recycling chain, it is likely that i) the lifetime of a TV is longer
than the assumed 15 to 25 years in South Africa, ii) the MFA did not assess the disposal pathways
sufficiently or iii) a substantial amount of TVs enter the areas of informal settlements like Kayalitsha
and Guguletu and are disposed of locally on illegal dumps. However, the time series carried out in
this study shows that the number of obsolete CRT TVs in the CMA will increase at least until 2020
to 2030.
It is expected that in the year 2007 some 400 tons of CRT monitors and 600 tons of TVs respectively will become obsolete in the CMA. In the year 2020, some 1600 tons of CRT monitors and
between 2000 and 2500 tons of CRT TVs are expected to become obsolete.
Scenario analysis
The assessment of CRT recycling alternatives shows that in the CMA there is already an efficient
system in place for the recycling of CRT devices but for the recycling of the CRT itself. At this
stage, stripped CRTs are landfilled either on the municipal solid waste landfill site or on the Vissershok hazardous landfill site. Locally there are only brick manufacturers and the building industry
able to include the CRT glass in their recycling process. However, these options clearly intend to
release CRT glass into the environment. At this stage, the assessed copper, lead and precious
metal smelters, as well as container glass producer in South Africa are not able to use CRT glass
in their process for technical and/or economical reasons.
From the best available technologies for the processing of CRT glass the CRT manufacturing and
copper / lead smelting are the current state of the art processes for the recycling of CRT glass.
Primary lead smelting as well as iron and zinc smelting is not suitable for the processing of CRT
glass. Other technologies such as CRT glass for the production of foam glass or clay bricks were
not assessed for South Africa in this study.
Multi Attribute Utility Theory
The Multi Attribute Utility Theory for the assessment of eight recycling scenarios for CRT screens
was carried out. The results unveil that the scenario where the CRT glass is pre-processed in the
CMA and then sent to a CRT manufacturer in Germany reaches the highest utility. The advantage
of this option is i) an increased potential for local economic growth, ii) a high environmental benefit
mainly due to the lead recovery and iii) a high social utility due to the creation of low-skilled and
highly skilled jobs locally. The disadvantages are a) relatively high net and investment costs compared to other scenarios. The robustness analysis showed that the CRT manufacturing option is
robust compared to the other scenarios.
The second best scenario is the lead recovery scenario. This option intends to ship the CRTs to
Europe to be included in the copper / lead smelting process. The advantages are a high recovery
rate for lead and that the remaining slag can be use in the building industry resulting in a high envi-
Dominik Zumbuehl
81
October 2006
CONCLUSIONS
ronmental utility. The disadvantages are high net costs, no increased potential for local economic
growth and a low social utility. The scenarios where the CRT glass is used in concrete rubble or in
the manufacturing of bricks reach almost the same utility that is below the utility of the CRT manufacturing scenario and the lead recovery scenario. According to the robustness analysis, there is no
significant difference between these and the lead recovery scenario. Thus, a ranking for these scenarios is not applicable. The baseline scenario where the CRTs are landfilled and the scenario
where the CRTs are transported to the lead mine for the infinite storage reach the lowest utility.
Thus, it is recommended to establish a recycling scenario similar to the CRT manufacturing scenario in the CMA. The recycling costs per CRT monitor would add up to some $1.2 and to around
$3 for a TV respectively. These costs could be covered by a fee at the time of disposal or with the
establishing of an e-waste recycling system, including an advanced recycling fee (ARF) paid at the
time of purchasing.
Dominik Zumbuehl
82
October 2006
OUTLOOK
6
OUTLOOK
MFA
It is important to increase the accuracy of the MFA with the investigation of more sales figures from
the manufacturers and the distributors because only a few reliable sales figures were available in
this study. In addition, sales figures from the retailers should also be assessed which was not the
case in this study.
Consumer based survey should be carried out rather than only the investigation of sales and import
figures. This would allow specifying the consumer stock changes, the disposal routes and the lifetimes of CRT monitors and TVs could be investigated. Furthermore, the use-phase and storage
phase of CRT devices at consumer levels should be investigated.
According to Desco Electronic Recyclers, there are many TV refurbishers in the CMA. For a more
reliable mass flow assessment of TVs, the flows from consumer to second hand use and from
there to the landfill or dumps should be investigated. Additionally the CRT flows into the informal
settlements (e.g. Kayalitsha and Guguletu) should be investigated in the future.
The Cape Town Waste Management Department intends the future monitoring of the collected ewaste within the municipal solid waste stream. Hence, these figures should be included in the MFA.
Scenario analysis
In this study, only a few South African players from the industry were asked to use CRT glass in
their processes. Thus it is important to systematically investigate the South African industry (e.g.
the smelting, glass and building industry) to either make sure that there is no feasible application
for the CRT processing or to find out new ways for the processing of CRT glass. For instance, the
Palabora Mining Company another copper smelter in South Africa was suggested to be evaluated
for the use of CRT glass by Boliden SA.
MAUT
The weighting of the attributes in the MAUT assessment was carried out at the regional workshop.
Only one representative of the industry and only one representative of the suppliers has participated the weighting. As these groups belong to the main drivers for a future recycling system for
CRT glass more representatives should be asked for the weighting of the attributes. In addition, it
would be important to weight the attributes hierarchically, which was not the case in this study. Also
the attribute set has to be proven if it covers all relevant aspects of the CRT recycling process.
For the environmental impact assessment, only data from Swiss or European processes were
available from the ecoinvent centre. Thus, it is important to generate life cycle inventory data for
processes in developing and industrialising countries such as South Africa to improve the quality of
the eco-indicator 99 values generated in this study.
Nevertheless the MAUT result show clearly that the recycling scenario including the local preprocessing and the manufacturing of CRT glass overseas is the best solution for the CMA at this
stage. As 90% of the global CRT production is located in China (Widmer et al., 2005) it is important
to assess similar solutions considering alternative pre-processing steps and CRT manufacturers in
other regions such as Asia or the USA.
Dominik Zumbuehl
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October 2006
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APPENDICES
APPENDICES
Appendix 1: Glossary
ARF
BAN
BAT
BC
BEP
CE
CMA
CRT
EC
EC50, EC20
EEE
EIC50
EI ‘99
EMPA
ESM
EU
EUR, €
GNP
ICER
LCD
LC50
LOEC
HDTV
MAUT
MFA
NGO
NOEC
OECD
PC
PWB
Recycling
RoHS
seco
SENS
StEP
SWICO
TCLP
TFT
UNEP
USD, $
WDI
WEEE
ZAR
Dominik Zumbuehl
Advanced Recycling Fee
Basel Convention Network
Best Available Technology
Basel Convention
Best Practice
Communication Executive
Cape Metropolitan Area
Cathode Ray Tube
European Community
Effect Concentration (for 50% and 20% of the tested subjecs)
Electronic and Electrical Equipment
Effective Inhibitory Concentration
Eco-Indicator 99
Eidgenössische Materalprüfungs- und Forschungsanstalt - Swiss Federal
Laboratories for Materials Testing and Research
Environmental Sound Management
European Union
Euro
Gross National Product
Industry Council For Electronic Equipment Recycling
Liquid Crystal Display
Median lethal concentration; it defines the concentration of a toxic substance or
radiation is the dose required to kill half of the members of a tested population.
Lowest Observable Effect Concetration
High Definition TV.
Multi Attribute Utility Theory
Mass Flow Assessment
Non Governmental Organization
No Observable Effect Concentration
Organisation for Economic Co-operation and Development
Personal Computer
Printed Wiring Board
Extraction of materials from a product in order to reuse them (UNEP, 2006).
Restrictions of Hazardous Substances
Swiss State Secretariat for Economic Affairs
Stiftung Entsorgung Schweiz – Foundation for disposal Switzerland
Solving the e-Waste Problem
Swiss Association for Information, Communication and Organisation TechnolToxicity Characteristic Leaching Procedure (US EPA Method)
Thin-Film Transistor, a field effect transistor
United Nations Environment Programme
US Dollar
World Bank World Development Indicator
Waste Electronic and Electrical Equipment
South African rand
92
October 2006
APPENDICES
Appendix 2: Definitions of e-waste
Reference
Definition
EU WEEE Directive (EU, 2002)
“Electrical or electronic equipment 2 which is waste 3… including all components, subassemblies and consumables, which are part of the product at the time of discarding”.
Directive 2002/96/EC of the European Parliament and of the Council (January 2003),
defines ten categories (see below).
Basel Action Network (Pucket et "E-waste encompasses a broad and growing range of electronic devices ranging from
al., 2002)
large household devices such as refrigerators, air conditioners, cell phones, personal
stereos, and consumer electronics to computers which have been discarded by their
users."
OECD (2001)
"Any appliance using an electric power supply that has reached its end-of-life."
SINHA (2004)
"An electrically powered appliance that no longer satisfies the current owner for its original purpose."
StEP (2005)
E-Waste refers to "…the reverse supply chain which collects products no longer desired
by a given consumer and refurbishes for other consumers, recycles, or otherwise processes wastes."
Categories of e-waste defined by the EU WEEE Directive (EU, 2002):
1.
Large household appliances
2.
Small household appliances
3.
IT and telecommunications equipment
4.
Consumer equipment
5.
Lighting equipment
6.
Electrical and electronic tools (with the exception of large-scale stationary industrial tools)
7.
Toys, leisure and sports equipment
8.
Medical devices (with the exception of all implanted and infected products)
9.
Monitoring and control instruments
10.
Automatic dispensers
2 “electrical and electronic equipment” is defined as equipment which is dependent on electric currents or electromagnetic
fields in order to work properly and equipment for the generation, transfer and measurement of such currents.
3 “waste” is defined as any substance or object which the holder disposes of or is required to dispose of pursuant to the
provisions of national law in force.
Dominik Zumbuehl
93
October 2006
APPENDICES
Appendix 3: Swiss State Secretariat for Economic Affairs’ global e-waste program
Facing up to the controversial issues of e-waste disposal the Swiss State Secretariat for Economic
Affairs (seco) has commissioned the Swiss Federal Laboratories for Materials Testing and Research (EMPA) to conduct a study. The main objective of the study was to propose a global program to improve existing e-waste management systems. This led to seco's global e-waste program
"Knowledge Partnerships in e-Waste Recycling" to be structured in three phases:
Phase 1:
Assessment of existing e-waste management systems (2003 – 2004)
Phase 2: Planning of improvements (2004 – 2005)
Phase 3: Implementing pilot projects (2005 – 2008)
The program's focus lays on 'capacity building' and 'knowledge management' and intents to mitigate negative externalities of information and communication technologies. It therefore contributes
to the sustainability of these new and promising technologies without dismissing industry from its
extended producer responsibilities.
The assessments during Phase I1were limited to case studies carried out in the capitals of the
three pre-selected countries China, South Africa and India. As a reference the Swiss e-waste management system was used. The results were published on a website (www.e-waste.ch) as the
“eWaste Guide” (Electronic Waste Guide, 2006) which serves as a knowledge base on e-waste
recycling. Among other things it highlights potential environmental hazards when dealing with ewaste and raises the awareness of the problem.
The case studies revealed specific needs for improvements in each of the three assessed countries. These specific needs led to different foci for the program implementation: support for policy
and legislation in China, technology & skills in India, and business and financing in South Africa.
During Phase 2 knowledge partnerships involving the different stakeholders had been established.
Following improvements to the current e-waste management systems were planned in a body. The
outcomes were agreed goals and strategies which are…
a) …at a local level the testing of practical improvements.
b) …at a national level the formulation of e-waste strategies.
The aim is to reduce safety and environmental hazards without reducing the attractiveness of the
business.
The ongoing Phase 3 focuses on implementing the planned activities in the three countries. The
program mainly provides technical assistance and advisory services to build capacity for a sustainable and effective e-waste management system. Also the knowledge sharing of the various stakeholders by integrating them in the global community of practice is supported.
Dominik Zumbuehl
94
October 2006
APPENDICES
Appendix 4: Import statistics from DTI and SARS; the TVs were derived from the total import figures minus the Video figures
Year
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
Tot colour
CRTs
540'335
360'191
475'799
514'083
374'677
412'592
404'675
482'171
416'710
431'168
468'955
534'977
705'418
693'064
Dominik Zumbuehl
Colour CRTs
Video
CRTs
Tot TV
2'501
537'834
3'876
356'315
4'155
471'644
12'433
501'650
3'393
371'284
1'867
410'725
681
403'994
150
482'021
1'327
415'383
728
430'440
753
468'202
786
534'191
808
704'610
88
692'976
Monochrome CRTs
TV in CMA
61'313
40'620
53'767
57'188
42'326
46'823
46'055
54'950
47'354
49'070
53'375
60'898
80'326
78'999
95
Total import
156'074
106'732
163'918
175'743
145'022
185'511
140'549
117'500
106'072
112'112
78'889
16'928
35'693
41
Video
9'129
2
10'867
0
24
5'849
25
172
590
14
16
65
5
4
TVs
146'945
106'730
153'051
175'743
144'998
179'662
140'524
117'328
105'482
112'098
78'873
16'863
35'688
37
TVs CMA
16755
12170
17452
20039
16533
20486
16023
13378
12028
12782
8994
1923
4069
4
October 2006
APPENDICES
Appendix 5: MFA computer monitors: specifications of the flows
from import
to distributor
to second hand supplier
FreeCom
import FreeCom
from distribution
to consumer *
AXIZ
MUSTEK (MECER)
Sahara Computers
Drive Control
Incredible Connection
MICO
Pinnacle Micro
rectron
Annex
Tarsus
Equity
from consumption
to second hand supplier
Smart City
Device SA
Recycling IT
to recycling
to landfill
Wasteman
Enviro Serve
Waste Control
Inter-Waste
from second hand supply
to consumer
FreeCom
Device SA
Recycling IT
Smart City
Stock at Smart City
from recycling
to recycler
plastics
copper
ferro
aluminium
PWBs & wires
gun
to landfill
tubes
landfill
to recycling
Stock calculations
consumer stock change
* derived from market shares
Dominik Zumbuehl
min
1466
1359
106
18
89
monitor flows metric tons
max
average
1723
1594
1617
1488
106
106
18
18
89
89
1359
163
291
0
177
-
1617
163
291
9
177
-
1488
163
291
46
44
0
2
53
35
35
0
0
0
50
44
0
5
89
53
53
0
0
0
48
44
0
4
71
44
44
0
0
0
109
106
0
0
2
44
125
106
9
0
9
31
117
106
5
0
5
0
53
9
3
5
1
3
0
89
16
5
8
1
5
0
71
12
4
6
1
4
0
32
53
43
0
1
1
1333
1550
1441
96
5
177
October 2006
APPENDICES
Appendix 6: Questionnaire sent to the distributors of CRT monitors and TVs in the CMA
QUESTIONNAIRE SALES FIGURES
Please use a fax machine to return the questionnaire (021 706 6622). Thank you.
name:
___________________________ position: _____________________ date: _____________________
phone: ________________
1.
Email: _________________________________
What are your company’s functions in South Africa?
manufacturer
2.
mobile phone: ______________
importer
distributor
retailer
Which of the following CRT-devices have you been providing to your Cape Town customer base?
TV sets
computer monitors
3.
Which are your distributors in / for Cape Town?1 _________________________________________________
4.
How many units had been sold in the past few years to your Cape Town customer base? (If no specific sales
figures for Cape Town are available, you can provide data from Western Cape or even national sales figures).
The below sales figures include numbers for:
Year
Cape Tow
CRT – TV sets
average screen
units sold
2
size or weight
Western Cape
South Africa
CRT - computer monitors
average screen
units sold
2
size or weight
2000
2001
2002
2003
2004
2005
Any statistics available
prior to the year 2000
5.
Which market share in % do you currently possess from the total market in Cape Town approximately for CRTTV sets and CRT-computer monitors respectively? (If no data of the CRT market share is available, you can
provide overall TV and monitor market shares from the total South African market.)
TV sets: ________ %
6.
computer monitors: ________ %
Does your company also provide lead-free TV sets or computer monitors based on CRT technology? If you do
so, what is the current percentage of the units you currently provide and since when do you provide your
customers with a lead-free CRT technology?
________________________________________________________________________________________
7.
Considering the phasing-out of the CRT-technology due to increasing replacements through plasma and LCD
technology: Can you give an estimate for the future sales figures of leaded TV sets and computer monitors?
CRT – TV sets
Year
units sold
CRT - computer monitors
average size or
1
weight
Units sold
average size or weight1
2006
2010
2020
1
2
If yourself are not a distributor
specify weight without packaging
Dominik Zumbuehl
97
October 2006
APPENDICES
Appendix 7: Penetrations rates of TVs and personal computers in South Africa
penetration rates of TVs and computers
160
50
South African population, total
television sets (per 1,000 people)
personal computers (per 1,000 people)
40
140
120
35
100
30
80
25
20
60
15
TVs / computers
South African population
[milions]
45
40
10
20
5
0
0
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
1966
1964
1962
1960
Year
Appendix 8: Detailed listing of WDI and SARS figures for the derivation of yearly and cumulated
inputs of TVs into the CMA
Source
Year
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
TV penetration rate
[units /1000 capita]
3.87
26.93
31.35
39.27
68.34
68.07
69.28
70.71
72.04
82.43
89.29
89.99
90.62
91.20
94.42
104.30
104.98
105.43
105.81
126.25
132.33
128.92
130.96
129.36
127.75
145.33
152.38
Dominik Zumbuehl
(WDI, 2003)
South African
Population
24'728'000
25'268'090
25'805'580
26'355'320
26'940'790
27'576'000
28'254'650
28'971'840
29'724'000
30'505'360
31'307'880
32'121'290
32'933'080
33'728'500
34'490'550
35'200'000
35'933'110
36'690'740
37'473'800
38'283'220
39'120'000
39'912'000
40'670'330
41'402'390
42'106'230
42'800'990
43'240'000
CMA TV
stock [units]
10'909
77'574
92'229
117'996
209'905
213'985
223'144
233'540
244'100
286'643
318'698
329'521
340'224
350'661
371'256
418'531
430'019
440'982
452'039
550'980
590'149
586'578
607'180
610'563
613'193
709'128
751'133
98
(Heyns, 2006)
Import figures
to CMA [units]
61'313
40'620
53'767
57'188
42'326
46'823
46'055
54'950
47'354
49'070
53'375
60'898
80'326
78'999
Cumulated
Input
10'909
77'574
92'229
117'996
209'905
213'985
223'144
233'540
244'100
286'643
318'698
329'521
340'224
350'661
371'256
418'531
430'019
491'332
531'952
585'720
642'908
685'234
732'057
778'112
833'062
880'416
929'486
982'861
1'043'759
1'124'085
1'203'084
Input per Year
[units]
10'909
66'666
14'655
25'767
91'908
4'081
9'159
10'396
10'560
42'542
32'055
10'823
10'703
10'437
20'596
47'275
11'488
61'313
40'620
53'767
57'188
42'326
46'823
46'055
54'950
47'354
49'070
53'375
60'898
80'326
78'999
October 2006
APPENDICES
Appendix 9: Relationship of weight, diameter and volume of currently (2006) sold TVs
Relationship Diameter, Weight and Volume of
CRT TVs
100
0.50
90
80
0.40
2
weight [kg]
60
0.30
50
40
0.20
volume [m3]
R = 0.871
70
30
2
R = 0.9177
20
0.10
10
0
0
20
40
60
80
0.00
100
diameter [cm]
Dominik Zumbuehl
w eight to diameter
volume to diameter
Exponentiell (w eight to diameter)
Exponentiell (volume to diameter)
99
October 2006
APPENDICES
Appendix 10: Toxicity and legislation of hazardous components in the CRT
In this Appendix the basic composition of the CRT glass is and the scree anf funnel glass coating is
calculated. In addition the toxic compoiunds of the glass and coatings are discussed. Human and
ecotoxicity is discussed as well as the regulatory limits for South Africa compared with international
standards and regulations.
There is much data from literature available which provide such figures. Due to a large variety in
the size and composition of computer monitors and TVs it is difficult to specify exact figures of the
several components. In this study the arithmetic average of the data found in literature (EMERG,
1996; ICER, 2004) was taken to derive the average content of every element in the CRT glass
which is shown in Table 18. The data from EMERG were taken for the composition of older CRT
glass where the ICER report represents rather newer CRT glass. The composition of the funnel
coating was derived from (Kemco International Associates, 2006). The front glass is coated with a
thin layer of fluorescent materials. These substances contained in the screen are generally
phosphides or sulphides of zinc, europium, yttrium and cadmium (5-10 grams per screen). In older
model tubes (manufactured before 1990), the fluorescent coating contains mainly cadmium and
zinc sulphide while the newer models contain 94% zinc sulphide and rare-earth metals (Vieto et al.,
1999). No exact composition of the screen coating was found. Nevertheless the composition was
derived from the specifications from the study of Vieto and Pratt (1999). It was further assumed that
the proportion of older and newer CRTs is 1:1 and that in the older CRTs cadmium and zinc was
used in the same quantities in connection with sulphides or phosphides.
old coating = 0.5 Cd X + 0.5 Zn X
(16)
X is a substitute for sulfide (S) or phosphide (P) respectively
The newer models were assumed to consist of 94% zinc sulphide (or phosphide) and to 3% of
Yttrium and to 3% of Europium respectively again in connection with the sulphides or phosphides.
new coating = 0.94 ZnX + 0.03 YX + 0.03 EuX
(17)
This leads to the following average stoichiometry for the mixing of old and new CRTs:
average coating = 1S +1P + 0.72 Zn + 0.25 Cd + 0.015 Y + 0.015 Eu
note: it was assumed that CRTs with new screen coating and such with old screen coating are
mixed evenly to derive the average composition. With the molecular weights (m) and the use of the
average stoichiometry the weight percentage (w%) specified in Table 17 was calculated using:
w% =
ni × mi
6
∑ ni × mi
× 100
(18)
i =1
i
1
2
3
4
5
6
element
P
S
Zn
Cd
Y
Eu
m [g/mol]
31.0
32.1
65.4
112.4
88.9
152.0
n [mol]
1
1
0.72
0.25
0.015
0.015
weight percent [w%]
21.8
22.6
33.2
19.8
0.9
1.6
Table 17: Derivation of the weight percentage of the luminescent screen coating used in CRTs
Dominik Zumbuehl
100
October 2006
APPENDICES
The resulting chemical composition of the average CRT glass is shown in Table 18. The elements
of concern from a toxicological point of view are lead oxide, barium oxide, antimony, cadmium and
zinc (sulphides or phosphides). All other elements will be neglected in this section.
Oxides in CRT glass [wt%]
SiO2
Al2O3
Na2O
K2O
CaO
MgO
BaO
ZnO
PbO
B2O3
SrO
Fe2O3
CoO
TiO2
CeO2
ZrO2
Sb2O3
Total oxides in glass
[kg / kg CRT]
0.545
0.023
0.075
0.069
0.017
0.008
0.079
0
0.048
0
0.015
0.001
0
0
0.001
0.004
0.003
0.887
wt% in fraction
61.38
2.57
8.43
7.72
1.90
0.92
8.88
0
5.44
0
1.67
0.15
0
0
0.16
0.43
0.33
100.00
Standard deviation [%]
0.81
0.47
0.51
0.23
1.06
0.67
1.82
Fe
0.1100
11.00
shadow mask and rimband
1
funnel coating
C
FeO
Na2SiO3
H 2O
0.0019
0.0002
0.0003
0.0002
0.0012
screen coating (luminescent layer)2
P
S
Cd
Y
Eu
Zn
0.0008
0.00018
0.00019
0.00017
0.00001
0.00001
0.00028
0.35
0.80
Graphite
Iron Oxide
Sodium Silicate Solids
Water
100
22
23
20
1
2
33
Phosphor
Sulfide
Cadmium
Yttrium
Europium
Zinc
1) 0.022 to 0.028mm coating on 0.5m2 for 1 CRT with a density of 1380kg / m3 and CRT weight of 8.91 kg; source: Kemco International Associates, 2006
2) 5-10g / CRT
Table 18: Average composition of CRT glass, the ferrous metals and the coatings within the CRT
Lead
Occurrence: Since metallic lead and common lead minerals such as sulphides, sulphates, oxides,
carbonates, and hydroxides are hardly soluble levels of dissolved lead in aquatic ecosystems are
generally low. The solubility in water for lead oxide is 1.7 mg/l (Stuff, 2005). The Agency for Toxic
Substances and Disease Registry ATSDR (1992) reported 1mg/l respectively. Most of the lead
entering aquatic ecosystems is associated with suspended sediments, while lead in the dissolved
phase is usually complexed by organic ligands (DWAF, 1996). The ratio of lead in suspended solids to lead in dissolved form has been found to vary from 4:1 in rural streams to 27:1 in urban
streams (EPA, 1986). The dissolved lead also undergoes hydrolysis. The hydrolysis constants pKi
for lead are 7.7, 9.4 and 11 respectively indicating that dissolved lead occurs mainly as Pb2+ up to
pH 7.7 and Pb(OH)- from pH 7.7 to pH 9.4. Lead Oxide also called Litharge is amphoteric thus it
reacts with either acids to form Pb2+ which is shown in equation (19).
PbO (s) + 2 H+ (aq) Æ Pb2+ (aq) + H2O (l)
(19)
or with bases to form lead(IV) hydroxide plumbic hydroxide shown in equation (20).
PbO (s) + H2O (l) + 2 OH- (aq) Æ Pb(OH)4 2- (s)
(20)
Hence decreasing pH increases the bioavailability of Pb2+.
Human Toxicity:
Dominik Zumbuehl
101
October 2006
APPENDICES
“Short-term exposure to high levels of lead can cause vomiting, diarrhoea, convulsions, coma or
even death. Other symptoms are appetite loss, abdominal pain, constipation, fatigue, sleeplessness, irritability and headache. Continued excessive exposure, as in an industrial setting, can affect
the kidneys. It is particularly dangerous for young children because it can damage nervous connections and cause blood and brain disorders.” (EMPA, 2004)
Eco-toxicity: Both aquatic and terrestrial organisms are affected by lead. Lead is cancer-causing,
and adversely effects reproduction, liver and thyroid function, and disease resistance (Eisler,
1988). Lead oxide has caused mutagenic effects in experimental animals (Dierks, 1995). The toxicity of lead to terrestrial organisms ranges from 40 mg Pb/kg d.w. (stadard soil) for Crustaceans to
1100 mg Pb/kg d.w. for Insects (Tukker et al., 2001). Toxicity tests with freshwater invertebrates
such as Brachionus calyciflorus, Chironomus tentans, and Lymnaea stagnalis were performed in
artificial freshwaters (Grosell et al., 2006). They measured no-observable-effect concentration
(NOEC), lowest-observable-effect concentration (LOEC), and calculated 20% effect concentration
(EC20) for each of the three species. The EC20 for the rotifer B. calyciflorus were 0.125 mg dissolved Pb/L, respectively. The midge C. tentans was less sensitive, with NOEC of 0.109 mg dissolved Pb/L, respectively, and the snail L.stagnalis exhibited extreme sensitivity, evident by EC20
of 0.004 mg dissolved Pb/L, respectively (Pesticide Action Network North America (PAN), 2006).
Aisemberg et al. (2005) performed the determinations of ALA-D (enzyme) activity in the whole body
soft tissues of pigmented and non-pigmented gastropods B. glabrata and in the oligochaete L.
variegatus. The organisms were exposed to varying concentrations of Pb for 48 h. The values of
Pb concentration that produce 50% of inhibition on the enzyme activity (EIC50) were 0.023 and
0.029 mg Pb/L for pigmented and non-pigmented B. glabrata, respectively. A much higher value
was found for L. variegatus (0.703 mg Pb/L). The non-observed effect concentration (NOEC) on
enzyme activity for the oligochaetes was 0.05 mg Pb/L, about twice the EIC50 calculated for the
gastropods. Bioconcentration factors of four species of invertebrates and two species of fish
ranged from 42 to 1700 (DWAF, 1996). Lead can be bioconcentrated from water, but does not bio
accumulate and tends to decrease with increasing trophic levels in freshwater habitats (Eisler,
1988).
Regulatory limits: Although lead oxide has a low solubility, the above results indicate that the
(aquatic) environment is highly affected by lead. Considering the very low level of 0.004mg/l, which
affects L.stagnalisand and the finding that the ratio of lead in suspended solids to lead in dissolved
form can be as little as 4:1 in rural streams, one has to conclude that 20% of the total Pb of a certain probe could theoretically be dissolved and therefore be toxic. This indicates that the maximal
dissolved lead concentration in freshwater systems mustn’t exceed 0.02 mg/l (0.004mg/l times 5).
Legislation on lead effluent in South Africa and Switzerland: The regulatory limits for lead containing effluents in South African freshwater systems are regulated in the provincial legislation. For
the Western Cape Province the limit for dissolved lead is 0.01 mg/l (Cape Metropolitan Council,
2000). According to the Swiss “Gewässerschutzverordnung” (GSchV, 1998), the lead content of
industrial effluents in freshwater systems must not exceed a total lead amount of 0.01 mg/l and the
dissolved fraction has to be below 0.001 mg/l Pb. Looking at the limits for potable water according
to the European Community Directive 83/98 (CELEX Nr: 398L0083) the lead content in drinking
water must not exceed 0.01mg/l. According to the Foodstuffs, Cosmetics and Disinfectants Act
(2006) the limit for bottled water in South Africa is 0.01mg/l as well.
The occupational exposure limit (OEL) for lead compounds other than tetra-ethyl lead is according
to the South African Lead Regulations, GN R 236 (28 February 2002) 0.15 mg / m3 air measured
in accordance with health and safety standards.
Leachability of lead from the lead oxide of CRTs: Leachates of landfill sites or run offs from
illegal dumps can vary widely in pH due to the large content of organic acids. Although lead oxide
Dominik Zumbuehl
102
October 2006
APPENDICES
(PbO) has a very low solubility in water (see above) and is inert under standard conditions (20°C
and pH of 7) the deposition of CRT glass has to fulfil the environmental regulations and has therefore to be proven in terms of its chemical behaviour and the variations in pH and redox-conditions.
According to a leachability study by Musson et al. (2000) using the EPA Toxicity Characteristic
Leaching Procedure (TCLP) the lead leached from the CRT samples at an average concentration
of 18.5 mg/L. This exceeded the regulatory limit of both the EPA and the South African legislation
by far. The most significant quantities of lead were obtained from the funnel portion of the CRTs at
an average lead concentration of 75.3 mg/L. Samples containing the frit seal had lead leaching
levels nearly 50 times those without. Samples comprised of smaller particle sizes exposed a
greater surface area resulting in higher lead leaching levels. Musson et al. (2000) tested 30 colour
CRTs and 21 exceeded regulatory lead limits, none of the six monochrome CRTs did. A different
study using also TCLP with the leachates from several MSW landfill sites was conducted by Jang
(2003). Lead concentrations ranged from 1.7 to 6.0 mg/L, with an average of 4.1 mg/L. Background
levels of lead in the landfill leachates ranged from less than detection limit (0.04 mg/L) to 0.07
mg/L.
Although the average lead contents unveiled by Jang are slightly below the EPA regulatory limit
there is evidence that the lead oxide in CRT tubes is leachable and thus the CRTs have to be disposed of on hazardous landfill sites rather than on municipal landfill sites or dumps. Alternatively
the CRT cullets can be diluted in a way that the maximal leachable dissolved lead is below the
limits for freshwater or bottled water concentration.
Barium
Occurrence: The following information were derived from the US Agency for Toxic Substances
and Disease Registry (ATSDR, 2005). Barium oxide is quite soluble in water. The solubility in water
is 34.8 g/L (at 20 °C). Barium oxide reacts rapidly with carbon dioxide in water to form barium hydroxide and barium carbonate. The barium in these compounds that is dissolved in water quickly
combines with sulphate or carbonate that are naturally found in water and become the longer lasting forms (barium sulphate and barium carbonate). Barium sulphate and barium carbonate are not
very toxic compounds. Airborne barium oxide, which can react to barium hydroxide but not to barium sulphate and barium carbonate, can cause severe effects on human health and safety.
Humant toxicity: There are many effects of barium described in the toxicological profile for barium
and barium compounds provided by. However, for barium oxide no toxicological information were
available in this study. Nevertheless, for barium hydroxide and other soluble compounds, it says:
“Barium compounds such as barium acetate, barium chloride, barium hydroxide, barium nitrate,
and barium sulfide that dissolve in water can cause harmful health effects. Most of what we know
comes from studies in which a small number of individuals were exposed to fairly large amounts of
barium for short periods. Eating or drinking very large amounts of barium compounds that dissolve
in water causes changes in heart rhythm or paralysis.” (ATSDR, 2005)
And:
“No studies were located regarding cancer in animals after dermal exposure to barium. However,
results of one skin-painting study with mice suggest that barium hydroxide extract derived from
tobacco leaf may act as a tumor-promoting agent.” (ATSDR, 2005)
Ecotoxicity: Acute toxicity levels of barium for aquatic biota was found to be 68 mg/l for Daphnia
magna (LeBlanc, 1980). For Lemna minor (a duck weed) affection of growth was observed at a
level of 26mg/l (Wang, 1986).
Dominik Zumbuehl
103
October 2006
APPENDICES
Regulatory limits: The regulatory limits for barium in bottled water is 0.7mg/l (Department of
Health / Departement van Gesondheid, 2006). The US EPA set a limit of 2.0 mg barium per liter of
drinking water (2.0 mg/L). The South African Occupational Health and Safety Act 85 (1993) regulates airborne soluble barium compounds to a total OEL of 0.5 mg/m3. The same limit is regulated
by the U.S. Department of Labour Occupational Safety & Health Administration OSHA, (2006).
Discussion: No studies on the leachability of barium oxide from CRT glass were found. However,
if the CRT glass is broken into cullets or ground to dust particles, barium could easily leach on the
landfill sites, as it is quite soluble in water. It is likely that barium forms sulphates and carbonates
which are both not very toxic compounds. The eco-toxicity of barium is also not considered to by a
very severe problem, as the effect concentrations are quite high. However, groundwater contamination should be avoided.
Severe threads can be expected by airborne barium that is inhaled during the transport and processing of CRT glass. Both barium oxide and barium hydroxide can harm the health of workers exposed to CRT glass dust.
Antimony
Antimony trioxide is used in the glass industry as a refining agent and colorant. In an exposure
assessment in the German glass industry, TWA antimony levels were as high as 0.351 mg/m3
(ATSDR, 1992).
Occurrence:
Sodium antimony is used as a melting agent in CRT glass. It provides necessary optical properties.
The percent of sodium antimony in a CRT is 0.2% in the funnel and 0.24% in the panel. Sodium
antimony has replaced arsenic, which was originally used in CRT glass. Sodium antimony is used
because it is much less hazardous than arsenic (Monchamp, 2000). The antimony in the CRT
glass occurs as antimony trioxide (Sb2O3). It is used as a fining agent to remove bubbles from the
molten glass melt. (ICER, 2004). Antimony trioxide can be reduced to antimony according to (21)
and can also be oxidized to Sb2 O5 (Qivx Inc, 2006).
Sb2 O3 + 6 H+ + 6 e- ↔ 2 Sb + 3 H2O
E0 = 0.152
(21)
Human toxicity: According to the Australian Department of the Environment and Heritage, (2006)
“… antimony compounds show toxic properties similar to those of arsenic. This depends on how
much antimony a person has been exposed to, for how long, and current state of health. Exposure
to high levels of antimony can result in a variety of adverse health effects. Breathing high levels for
a long time can irritate eyes and lungs and can cause heart and lung problems, stomach pain, diarrhoea, vomiting, and stomach ulcers. Ingesting large doses of antimony can cause vomiting. Antimony can irritate the skin on prolonged contact.”
Effects of antimony trioxide (Sb2O3): Health effects have been observed in humans and animals
following inhalation exposure to antimony trioxide as shown in the list below. Note: all data were
retrieved from the US Agency for Toxic Substances and Disease Registry (ATSDR, 1992). Note:
The literature entries according to the citations in the following list are not listed in the references of
this study:
•
Guinea pigs exposed to approximately 37.9 mg antimony/m3 as antimony trioxide dust for
52-125 days (Dernehl et al. 1945) or guinea pigs died.
•
Occupational exposure to antimony trioxide and/or pentoxide dust (8.87 mg antimony/ m3
or greater) resulted in antimony pneumoconiosis (inflammation of the lungs due to the irritation caused by the inhalation of dust) (Cooper et al. 1968; Potkonjak and Pavlovich 1983;
Dominik Zumbuehl
104
October 2006
APPENDICES
Renes 1953) Chronic interstitial inflammation was also observed in rats exposed to 0.07
mg antimony/ m3 for 1 year with a 1 year recovery.
•
Alopecia was noted in rats exposed to 0.92 mg antimony/ m3 or greater as antimony trioxide for 13 weeks (Bio/dynamics 1985).
•
Hyperplasia of the reticuloendothelial cells in the peribronchiolar lymph nodes was observed in rats exposed to 0.07 mg antimony/m3 antimony trioxide for 1 year with a 1 year
recovery period (Bio/dynamic 1990).
•
Alopecia was noted in rats exposed to 0.92 mg antimony/m3 or greater as antimony trioxide
for 13 weeks (Bio/dynamics 1985).
•
Fibrosis and lipoid pneumonia have been reported in rats chronically exposed to 1.6 mg
antimony/m3 or higher as antimony trioxide or to 17.48 mg antimony/m3 as antimony trisulfide (Bio/dynamics 1990; Gross et al. 1952; Groth et al. 1986; Watt et al. 1980,1983; Wong
et al. 1979).
•
Factory workers exposed to antimony trioxide (0.042-0.70 mg antimonym3) had elevated
urine and blood antimony levels (Ludersdorf et al. 1987).
The above effects are not explained any further in this section. The intention is only to show the
variety of effects, mostly long term effects at low doses of antimony trioxide. The atmospheric halflife for antimony trioxide is estimated to 3.2 days (Mueller, 1985).
Ecotoxicity: For the Gastrophryne carolinensis (Eastern Narrow-Mouthed Toad) the LC50 is 50ug/l.
The LC50 for rainbow trouts Oncorhynchus mykiss was detected at 170ug/l. The LC50 for Americamysis bahia (opossum shrimp) is 4150 ug/l (Pesticide Action Network North America (PAN), 2006)
Regulatory limits: For drinking water the level of antimony is regulated to 5 ug/l according to the
South African Regulations Relating To All Bottled Waters (Foodstuffs Cosmetics and Disinfectants
Act, 2006). The U.S. and Canadian drinking water standards allow a maximum concentration of 6
ug/l (Pesticide Action Network North America (PAN), 2006). The South African Occupational Health
and Safety Act 85 (1993) regulates airborne antimony compounds to a total OEL of 0.5 mg/m3.
Discussion
The antimony trioxide present in CRTs seems to be hazardous when employees are exposed to
airborne particles for a long period of time or in high doses. Animal test show that long-term effects
occur at concentrations below 1mg/m3. No information of the faith of antimony trioxide in water was
found.
Cadmium
Occurrence: The cadmium in CRTs occurs as cadmium sulphide (CdS) in the screen coating and
can easily get airborne once the CRT is crashed.
The following properties and toxicological information of cadmium sulphide were retrieved from the
Agency for Toxic Substances and Disease Registry (ATSDR, 1999).
Behaviour of cadmium and cadmium sulphide in water: Under reducing conditions (which as are
present in leachates of landfill sites) cadmium can be reduced to form cadmium sulphide. Cadmium
sulphide, cadmium carbonate, and cadmium oxide, are practically insoluble in water. An aqueous
suspension of cadmium sulphide can gradually photo oxidize to soluble cadmium. Cadmium sulphide can also get soluble under acid conditions. The soluble Cadmium is the most toxic compound.
Dominik Zumbuehl
105
October 2006
APPENDICES
Behaviour of cadmium and cadmium sulphide in air: cadmium sulphide may photzolyse to cadmium sulphate in aqueous aerosols.
Toxicity to animals: In general for both the acute and chronic toxicity the more soluble cadmium
compounds such as cadmium oxide and cadmium chlorite seem to be more toxic. Accordingly
cadmium sulphate and cadmium sulphide are the least toxic compounds (Klimisch, 1993). A reason for this difference in toxicity is the higher lung absorption and retention times for the more soluble compounds (Rusch et al., 1986). A long-term effect study of the exposure of rats to cadmium
sulphide dust unveiled that: “0.090 mg Cd/m3 was not lethal during the exposure period but was
lethal to more than 75% of the males and females by 12 months postexposure. In these chronic
studies, cadmium’s lethal effects differed among the chemical forms in the following order from
most to least toxic: CdCl2>CdSO4 ≈ CdO dust>CdS, but lethality still occurred from all forms of
cadmium.” (Oldiges et al., 1986). Oldiges (1989) also experienced increased tumors in male and
female rats exposed to cadmium oxide and cadmium sulphide dust at 30 μg/m3 and 90 μg/m3 respectively.
Human toxicity: “The primary health risks of long term exposure are lung cancer and kidney damage. Due to the long half-life in the body, cadmium can easily be accumulated in amounts that
cause symptoms of poisoning.” (EMPA, 2004).
Ecotoxicity: Cadmium is very highly toxic to aquatic organism. The toxicity for the most affected
organisms is for Daphnia magna (Water flea) 33.6 ug/l, Ischnochiton hakodadensis (Chiton) 20.0
ug/l, Pimephales promelas (Fathead minnow) 13.9 ug/l and for Oncorhynchus mykiss (Rainbow
trout) 97.4 ug /l respectively. These figures are summaries from several studies carried out for each
of the aquatic organism. All data were collected from (Pesticide Action Network North America
(PAN), 2006)
Regulatory limits: For industrial effluents the concentration of cadmium is limited to 5 mg/l
(Province of Western Cape, 2006). The regulatory limit for cadmium in bottled water in South Africa
is 3 ug/l (Foodstuffs Cosmetics and Disinfectants Act, 2006). The US fresh water quality attributes
for continuous exposure to cadmium is 2.2 ug /l (Pesticide Action Network North America (PAN),
2006). The Swiss law for the effluent in freshwater systems sets the limit for industrial effluents in
freshwater systems to 100 ug /l. The concentration in freshwater systems shall not exceed 0.2 ug/l
whereas the dissolved partition must be below 0.05 ug/l (GSchV, 1998). The South African Occupational Health and Safety Act 85 (1993) regulates airborne cadmium compounds to a total OEL of
0.05 mg/m3 and for cadmium sulphides (which is actually present in CRTs) 0.04 mg/m3 respectively.
Discussion: Cadmium sulphide is the least toxic compound from the discussed in this section.
However it can be transformed to more soluble compounds such as Cd2+ by photo oxidation or
under acid conditions. On the other side under reducing conditions Cd2+ can be transformed to
cadmium sulphide again. Thus in aqueous solutions many reactions can occur and form insoluble
and soluble compounds depending much on the prevailing conditions. Cadmium is highly toxic to
aquatic organisms and should therefore not be released in the environment.
Long term effects of airborne cadmium sulphide unveiled that mammals are affected even by the
least toxic cadmium sulphide. The post exposure lethal dose was 0.090 mg Cd/m3. Thus airborne
cadmium sulphide can harm the health of workers exposed to. The OEL for cadmium sulphide is
0.04mg/m3
Zinc
Zinc is also present in the luminescent coating of the screen glass. It occurs as either zinc sulphide
or zinc phosphate. Like cadmium the zinc compounds are able to get airborne and into the soil or
Dominik Zumbuehl
106
October 2006
APPENDICES
water. Zinc phosphate is non toxic. The solubility of zinc sulphide is 6.5 to 6.9 mg/L at 18°C
(ATSDR, 2005). Thus Zn2+ can be formed from zinc sulphide in aqueous solutions.
For zinc sulphide no legal or toxicological data were available. Thus in this section the toxicity and
the legal regulations for zinc is discussed.
Environmental toxicity:
Eastern Narrow-Mouthed Toad Gastrophryne carolinensis
Fleshy prawn Penaeus chinensis
Brook trout Salvelinus fontinalis
Pacific oyster Crassostrea gigas
Chiton Ischnochiton hakodadensis
Water flea Daphnia magna
Scud Hyalella azteca
10 ug/l
412.5 ug/l
960.0 ug/l
75.0 ug/l
20.0 ug/l
742.7 ug/l
73.0 ug/l
Regulatory limits: For industrial effluents the concentration of zinc is limited to 30 mg/l. (Province
of Western Cape, 2006). The Swiss law for the effluent in freshwater systems sets the limit for industrial effluents in freshwater systems to 2 mg/l. The concentration of zinc in freshwater systems
shall not exceed 0.02 mg/l whereas the dissolved partition must be below 0.005 mg/l (Der
Schweizerische Bundesrat, 1998). The South African Occupational Health and Safety Act 85
(1993) regulates airborne zinc oxide to a total OEL of 5 mg/m3.
Discussion
Zinc phosphate is not toxic. For zinc sulphide no toxicological data nor regulatory limits were available. Aquatic biota is highly affected to Zn2+.
Discussion
For all of the investigated hazardous compounds occurrence and toxic concentrations differ much
and the effects on human health and the environment as well. However it is important to make sure
that the CRT glass which is released in the environment or is used in secondary applications has to
be diluted in a way that the resulting concentrations of hazardous substances is below any regulatory limit. The transport and the recycling of CRT glass can lead to airborne hazards mainly from
the screen coatings. Thus the work steps must be designed in a way that the airborne hazards are
minimized and that the remaining concentrations in the environment adhere to the regulatory limits
particularly the occupational exposure limits (OEL) have to be monitored.
Dominik Zumbuehl
107
October 2006
APPENDICES
Appendix 11: Furnace batch composition and material savings; Samsung Corning CRT manufacturing plant
Material svaings per 1000kg recycling CRT glass at Samsung Corning, Germany
cone glass
Screen glass
compound
chemical formula
kg
%
kg
%
SiO2
451.4
40.90
523.4
44.69
Sand
(Ba,Ca,Na,K,NH4)(Al
112.8
10.22
107.5
9.18
Feldspar
Na2CO3
Soda Ash
113.2
10.26
129.3
11.04
K2CO3
64.6
5.85
62.6
5.34
Potash
Leadoxide
PbO
189.4
17.16
0
0.00
CaMg(CO3)2
100.9
9.14
17.4
1.49
Dolomite
KNO3
Potassium Nitrate
11.8
1.07
26
2.22
Sodium Antimonate NaSbO3
2.1
0.19
4.7
0.40
BaCO3
28.4
2.57
129.4
11.05
Barium Carbonate
Strontium Carbonate SrCO3
29.1
2.64
121.4
10.36
CaCO3
0
0.00
17.7
1.51
Calcite
ZrSiO4
Zirconium Silicate
0
0.00
24.5
2.09
TiO2
0
0.00
3.6
0.31
Titanoxide
CeO2
0
0.00
2.7
0.23
Ceroxide
Zinc Oxide
ZnO
0
0.00
1.1
0.09
Rohstoffe gesamt
100.00
100.00
1103.7
1171.3
Dominik Zumbuehl
108
screen & cone glass
kg
%
487.4
42.79
110.15
9.70
121.25
10.65
63.6
5.60
94.7
8.58
59.15
5.31
18.9
1.64
3.4
0.30
78.9
6.81
75.25
6.50
8.85
0.76
12.25
1.05
1.8
0.15
1.35
0.12
0.55
0.05
100.00
1137.5
October 2006
APPENDICES
Appendix 12: Constants used for the MAUT assessment of the recycling scenarios
Input parameter
Shipping of a 40 feet container
Factor for nautical mile to km
20 feet containers (FEU) per freighter
40 feet containers (FEU) per freighter
Speed: 23 kn
Max load container
Transport of container within CMA
Transport of container within CMA
Costs Cape Town to Hamburg
Costs Hamburg to Samsung Corning
Costs Cape Town to Antwerp
Costs Antwerp to Metallo-Chimique
Ships complement
Low-skilled employees
Highly skilled employees
"super-link" truck
Max. weight
Costs from Cape Town to Johannesburg
Costs from Cape Town to Agganey
Costs from Cape Town to Agganey
Desco trailer
max. weight
Fuel use
Transport with car and trailer
Container tranport on road
"Superlink" transport (50 tons) on road
Wages
Low-skilled worker
Semi-skilled
Highly skilled
Crushing and sorting plant
Investment costs for separation plant
Production volume
Net costs
Net labour costs
Employees
Revenues for CRT glass cullets
Thomson
Screen glass
Funnel glass
Mixed glass
Samsung Corning
Screen glass
Funnel glass
Mixed glass
average revenue at Samsung Corning
Fuel prices South Africa
Petrol unleaded (for car)
Diesel 0.05% (for lorries)
Diesel 0.005% (for lorries)
Heavy Fuel Oil (for shipping)
Wages South Africa
Low-skilled worker
Semi-skilled
Highly skilled
Currency exchange rates
€ --> $
$ --> ZAR
€ --> ZAR
Dominik Zumbuehl
pc
pl
pl
ps
wu
ws
wh
Value
Unit
Rel. error
Sources
1.852
5'000
2'500
42
23'500
1'260
175
3'712
1'107
3'712
347
12
6
6
km/h
kg
ZAR
$
$
$
$
$
-
psl
50'000
12'000
6'000
834
kg
ZAR
ZAR
$
50%
LT
1000
kg
25%
Authors estimation accord-
ft
fc
fs
l/100km
l/100km
l/100km
$/h
2.08
4.17
11.12
25%
10%
10%
Authors estimation
(Balzer, 2006)
calculated
wu
ws
wh
15
32
40
ZAR/ h
15
30
80
25%
50%
50%
Experienced in SA
Authors estimation
Authors estimation
vp
Cn
Cnl
e
$
5'000
642
401
11
1'284'700
kg/h
$/h
$/h
-
25%
25%
10%
10%
25%
SwissGlas, (Apfel, 2006)
rsg
rfg
rmg
rT
$/kg
$/kg
$/kg
$/kg
-0.154
-0.154
-0.103
-0.137
rsg
rfg
rmg
rS
$/kg
$/kg
$/kg
-0.122
-0.148
-0.135
TEU
FEU
vs
Lc
CCMA
CCH
CHS
CCA
CAM
sc
ue
he
LSL
ZAR/l
6.6
6.3
6.3
EUR/l
$/l
0.71
0.92
0.68
0.88
0.68
0.88
0.44
0.34
ZAR/ h
$/h
15
2.08
25%
30
4.17
50%
80
11.12
50%
Exchange rate
0.778
0.139
0.108
109
10%
10%
25%
10%
10%
10%
10%
10%
25%
(Gsponer, 2006)
(Gsponer, 2006)
(Gsponer, 2006)
(Gsponer, 2006)
(Faragher, 2006)
(Faragher, 2006)
(Faragher, 2006)
(Pulko, 2006)
(Faragher, 2006)
(Heyns, 2006)
(Gsponer, 2006)
(Gsponer, 2006)
(Gsponer, 2006)
50%
(Bradford, 2006)
Authors estimation
25%
Samsung Corning
Samsung Corning
Samsung Corning
25%
http://www.shell.co.za/vpower/pprice.htm, 01.09.2006
(Gsponer, 2006)
Experienced in SA
Authors estimation
Authors estimation
Source
1.285
google.com
7.195
google.com
9.243
google.com
Date
24.08.2006
01.09.2006
01.09.2006
October 2006
APPENDICES
Appendix 13: Supporting calculations use din the MAUT assessment
Scenario 0
Economics
Transport costs:
ft × d × pc
tc =
L t × 100
Labour costs:
lc =
t × ws
Lt
Disposal costs:
lfc
dc =
Lt
Social
Working hours:
Ws =
t
Lt
Abbr.
Description
Unit
Value
Rel. error [%]
tc
ft
d
pc
LT
Transport costs
Fuel use van with trailer
Distance
Fuel price car
Load trailer
$/kg CRT
l/100 km
km
$/litre
kg CRT
0.0083
15
60
0.92
1’000
70
50
10
10
10
lc
t
ws
Lt
Labour costs
Time used for transport
Load trailer
$/kg CRT
h
$/h
kg CRT
0.0083
2
4.17
1’000
125
50
50
25
dc
lfc
Lt
Disposal costs
Landfilling costs
Load trailer
$/kg CRT
$/ton
kg
0.0278
27.8
1’000
50
25
25
Ws
t
Lt
Work for semi-skilled worker
Time used
Load trailer
h/kg CRT
h
kg
0.003
3
1’000
60
50
25
Abbr.
Description
Unit
Value
Rel. error [%]
tc
psl
LSL
Transport costs
Price for “super-link” to lead
mine
Load “super-link”
Labour costs
Time used for load/unload,
storage
$/kg CRT
$
kg CRT
0.0170
848
50’000
75
50
25
$/kg CRT
h
$/h
kg CRT
0.0003
6
2.08
50’000
100
50
25
25
Work for semi-skilled worker
h/kg CRT
h
kg
0.00042
21
50’000
75
50
25
Scenario 1
Economics
Transport costs:
p
tc = SL
L SL
Labour costs:
lc =
t × ws
L SL
Social
Working hours:
Ws =
t
L SL
Dominik Zumbuehl
lc
t
ws
LSL
Ws
t
LSL
110
October 2006
APPENDICES
Scenario 2, 3, 3a
Economics
Transport costs:
tc =
c CMA
LC
Labour costs lowskilled:
lc =
tL × w L
LC
Labour costs highly
skilled:
lc =
th × w h
LC
Additional costs:
ac =
ca
LC
Abbr.
Description
Unit
Value
Rel. error [%]
tc
pCMA
LC
Transport costs
Price for container within CMA
Load container
$/kg CRT
$
kg CRT
0.0075
175
23’500
20
10
10
lc
tL
wL
LC
Labour costs
Time used for low-skilled worker
Load container
$/kg CRT
kg CRT
h
$/h
0.0004
5
2.08
23’500
85
50
25
10
lc
LSL
th
wh
Labour costs
Load container
Time used for highly skilled work
$/kg CRT
kg CRT
h
$/h
0.0009
23’500
2
11.12
75
10
25
50
ac
ca
LC
Additional costs
Costs for chemical analysis
Load container
$/kg CRT
$
kg CRT
0.0273
642
23’500
35
25
10
Wu
t
Lt
Work for low-skilled workers
Time used
Load container
h/kg CRT
h
kg
0.00026
6
23’500
60
50
10
Ws
t
Lt
Work for highly skilled worker
Time used
Load container
h/kg CRT
h
kg
0.00009
2
23’500
35
25
10
Social
Working hours:
Wu =
t
Lc
Working hours:
t
Wh =
Lc
Dominik Zumbuehl
111
October 2006
APPENDICES
Scenario 3b
Economics
Transport costs:
tc =
c CMA
LC
Labour costs lowskilled:
lc =
tL × w L
LC
Labour costs highly
skilled:
lc =
th × w h
LC
Additional costs:
ac =
ca
LC
Crushing costs
cc =
e × wu
C × WCRT
Average weight of
CRT
WCRT =
w mon × w TV
2
Abbr.
Description
Unit
Value
Rel. error [%]
tc
pCMA
LC
Transport costs
Price for container within CMA
Load container
$/kg CRT
$
kg CRT
0.0075
175
23’500
20
10
10
lc
tL
wL
LC
Labour costs
Time used for low-skilled worker
Load container
$/kg CRT
h
$/h
kg
0.0004
5
2.08
23’500
60
25
25
10
lc
LSL
th
wh
Labour costs
Load container
Time used for highly skilled work
$/kg CRT
kg CRT
h
$/h
0.0009
23’500
2
11.12
75
10
25
50
ac
ca
LC
Additional costs
Costs for chemical analysis
Load container
$/kg CRT
$
kg CRT
0.0273
642
23’500
35
25
10
cc
C
WCRT
e
wu
Crushing operating costs
Capacity of crusher
Number of employees
Wage for semi-skilled worker
$/kg CRT
units/h
kg
$/h
0.0007
600
15.3
3
2.08
95
25
25
25
25
WCRT
Wmon
WTV
Average weight monitor CRT
Average weight monitor CRT
kg
kg
kg
15.3
11.12
21.7
10
10
20
WE
Pcrusher
C
WCRT
Work crusher
Power consumption crusher
Capacity of crusher
kWh/kg CRT
kW
units / hour
kg
0.008
74.57
600
15.3
70
10
50
10
Wu
t
Lt
Work for low-skilled workers
Time used
Load container
h/kg CRT
h
kg
0.00026
6
23’500
60
50
10
Wu
e
C
WCRT
Working generated from crusher
Number of employees
Capacity of crusher
h/kg CRT
units / h
kg
0.00033
3
600
15.3
35
25
10
Ws
t
Lt
Work for highly skilled worker
Time used
Load container
h/kg CRT
h
kg
0.00009
2
23’500
35
25
10
Environment
Work of crusher:
W =
E
P
crusher
C × w CRT
Social
Working hours:
t
Wu =
Lc
Working hours:
e
wu =
C × w CRT
Working hours:
t
Wh =
Lc
Dominik Zumbuehl
112
October 2006
APPENDICES
Scenario 4
Economics
Transport costs:
tc =
CCMA + CCH + CHS
LC
Costs for pre-processing:
lc =
(c n
− c nl + e × w s )
Vp
Revenues for glass cullets:
r=
(rT
+ rS )
2
Abbr.
Description
Unit
Value
Rel. error [%]
tc
psl
Ls
CCH
CHS
Transport costs
Costs for container within CMA
Load container
Costs CMA - Hamburg
Costs Hamburg - Samsung Corning
$/kg CRT
$
kg CRT
$
$
0.2125
175
23’500
3’712
1’107
20
10
10
10
10
lc
cn
cnl
e
ws
Vp
Labour costs
Net costs
Net labour costs
Number of employees
Production volume
$/kg CRT
$/h
$/h
$/h
kg/h
0.058
642
401
11
4.17
5’000
37
10
10
25
50
10
r
rT
rS
Revenue from CRT manufacturer
Average revenue at Samsung Corning
$/kg CRT
$/kg CRT
$/kg CRT
0.136
0.137
0.135
20
10
10
wu
tup
tt
tp
Vp
LC
Working hours for low-skilled workers
Time used at port
Production volume
Load container
h/kg CRT
h
h
h
kg CRT
kg
0.0018
8
4
0.1
5’000
23’500
38
25
25
100
25
10
wu
thp
VP
Working hours for highly skilled
Production volume
h/kg CRT
h
kg CRT
0.00026
5’000
5000
50
25
25
woSA
dCH
sc
vs
FEU
tHS
LC
Working hours outside South Afirca
Distance Cape Town - Hamburg
Speed of freighter
Time used from Hamburg to Samsung
Load container
h/kg CRT
km
km/h
h
kg
0.00027
11882
12
42
2'500
5
23'500
55
10
25
10
10
50
10
Social
Working hours low-skilled
and semi-skilled:
wu =
t up
VP
×
t t + tp
LC
Working hours highly skilled:
wh =
thp
Vp
Working hours outside
South Africa:
w oSA =
dCH × sc
t
+ HS
v s × FEU × LC LC
Dominik Zumbuehl
113
October 2006
APPENDICES
Scenario 5
Unit
Value
Rel. error
[%]
Transport costs
Costs for container within CMA
Load container
Shipping costs to Antwerp
Shipping to Metallo-Chimique
$/kg CRT
$
kg CRT
$
$
0.1802
175
3712
347
23'500
20
10
10
10
10
wu
tt
tp
Lc
Working hours for low-skilled workers
Time used at port
Load container
h/kg CRT
h
h
kg
0.00017
4
0.1
23’500
36
25
50
10
woSA
dCA
sc
vs
FEU
tHS
Working hours outside South Afirca
Distance Cape Town - Antwerp
Speed of freighter
Time used from Antwerp to MetalloChimique
Load container
h/kg CRT
km
km/h
h
0.00010
11423
12
42
2'500
1
kg
23'500
93
80
10
25
10
25
110
10
Abbr.
Description
tc
psl
Ls
CCA
CHS
Economics
Transport costs:
tc =
CCMA + CCA + CAM
Lc
Social
Working hours low-skilled
and semi skilled:
wu =
t t + tp
Lc
Working hours outside
South Africa:
w oSA =
dCA × sc
t
+ AM
v s × FEU × LC L C
Lc
Dominik Zumbuehl
114
October 2006
APPENDICES
Appendix 14: Environmental gain and loss assessment of all scenarios; EI ‘99 and Impact 2002+
IMPACT 2002+
EI'99 (H,A)
Env. loss
Env. gain
total
Unit
[Units / kg CRT]
Points
Transport, van <3.5t
tkm
0.06
5.08E-03
6.84E-06
2.03E-08
1.01E-07
1.73E-06
2.22E-07
kg
1
1.30E-03
2.99E-07
6.66E-06
1.27E-08
1.71E-08
2.77E-04
6.38E-03
7.14E-06
6.68E-06
1.14E-07
1.75E-06
2.77E-04
Scenario and processes
climate
change
aquatic
ecotoxicity
terrestrial acid.
& nutr.
terrestrial
ecotoxicity
human toxicity
Points
Szenario 0 - Landfill
TOTAL
Szenario 1 - Lead Mine
tkm
1.12
1.71E-02
1.83E-05
6.62E-08
6.08E-07
5.60E-06
6.78E-07
kg
1
1.30E-03
2.99E-07
6.66E-06
1.27E-08
1.71E-08
2.77E-04
1.84E-02
1.86E-05
6.73E-06
6.21E-07
5.62E-06
2.78E-04
TOTAL
Szenario 2 - Concrete rubble
tkm
0.04
6.52E-04
6.56E-07
2.66E-09
2.31E-08
2.62E-07
2.67E-08
Disposal, building, brick, to sorting plant
kg
-0.3
-1.63E-03
-4.17E-07
-1.38E-09
-1.63E-08
-7.95E-08
-1.22E-08
Disposal, building, concrete, not reinforced, to sorting plant
kg
-0.3
-1.64E-03
-4.35E-07
-1.41E-09
-1.72E-08
-8.07E-08
-1.25E-08
Disposal, building, reinforced concrete, to sorting plant
kg
-0.4
-2.22E-03
-6.36E-07
-1.99E-09
-2.59E-08
-1.10E-07
-1.73E-08
kg
1
1.30E-03
2.99E-07
6.66E-06
1.27E-08
1.71E-08
2.77E-04
-3.54E-03
-5.33E-07
6.66E-06
-2.36E-08
8.90E-09
2.77E-04
TOTAL
Szenario 3 - Concrete Bricks of RCA
tkm
0.03
4.89E-04
4.92E-07
1.99E-09
1.73E-08
1.97E-07
2.00E-08
kg
-0.965
-5.36E-03
-1.53E-06
-4.81E-09
-6.25E-08
-2.65E-07
-4.18E-08
-4.87E-03
-1.04E-06
-2.82E-09
-4.52E-08
-6.80E-08
-2.18E-08
TOTAL
Szenario 3a - Concrete Bricks
tkm
0.03
4.89E-04
4.92E-07
1.99E-09
1.73E-08
1.97E-07
2.00E-08
Sand, at mine
kg
-0.47
-9.45E-05
-1.11E-07
-5.73E-10
-4.04E-09
-1.16E-08
-4.98E-09
kg
-0.47
-1.24E-04
2.71E-04
-1.97E-07
1.84E-07
-1.27E-09
1.47E-10
-5.64E-09
7.62E-09
-2.74E-08
1.58E-07
-1.25E-08
2.52E-09
2.00E-08
Gravel, crushed, at mine
TOTAL
Szenario 3b - like S3 with Andela crushing device
tkm
0.03
4.89E-04
4.92E-07
1.99E-09
1.73E-08
1.97E-07
kWh
0.008
3.59E-05
9.84E-08
5.59E-10
7.22E-10
1.02E-08
3.14E-09
kg
-0.965
-5.36E-03
-1.53E-06
-4.81E-09
-6.25E-08
-2.65E-07
-4.18E-08
-4.84E-03
-9.40E-07
-2.26E-09
-4.45E-08
-5.78E-08
-1.87E-08
2.00E-08
TOTAL
Szenario 4 - CRT to CRT, EU
tkm
0.03
4.89E-04
4.92E-07
1.99E-09
1.73E-08
1.97E-07
kWh
0.025
1.12E-04
3.08E-07
1.75E-09
2.26E-09
3.18E-08
9.80E-09
Water
kg
0.1
1.01E-06
1.54E-09
1.72E-09
1.83E-11
1.61E-10
1.69E-10
Hazardous waste to hazardous waste incineration
kg
0.005
2.91E-04
9.25E-07
1.19E-08
4.24E-09
3.42E-08
5.55E-08
tkm
0.02
3.26E-04
3.28E-07
1.33E-09
1.15E-08
1.31E-07
1.34E-08
Transport, transoceanic freight ship
tkm
11.882
1.52E-02
1.25E-05
2.38E-08
8.46E-07
8.75E-07
2.67E-07
tkm
0.6
9.78E-03
9.84E-06
3.98E-08
3.46E-07
3.94E-06
4.01E-07
Natural gas, burned in industrial furnace >100kW
MJ
-0.129
-5.59E-04
-8.49E-07
-3.70E-10
-2.53E-09
-1.11E-08
-1.91E-09
kg
-0.011
-1.67E-04
-4.04E-07
-7.78E-10
-4.15E-09
-2.12E-08
-8.77E-09
kg
-0.288
-3.89E-04
-5.99E-07
-1.50E-09
-5.79E-09
-8.35E-08
-7.78E-09
Feldspar, at plant
kg
-0.065
-1.76E-04
-2.26E-07
-4.69E-10
-3.79E-09
-3.04E-08
-4.48E-09
Soda, powder, at plant
kg
-0.072
-1.58E-03
-3.02E-06
-1.71E-08
-9.79E-08
-5.57E-07
-2.82E-07
Potassium chloride, as K2O, at regional storehouse
kg
-0.038
-1.57E-03
-1.76E-06
-4.79E-09
-2.79E-08
-2.16E-07
-6.42E-08
kg
-0.056
-5.45E-02
-8.34E-06
-5.05E-07
-5.60E-07
-3.79E-05
-3.10E-06
Dolomite, at plant
kg
-0.035
-3.02E-03
-9.14E-08
-2.26E-10
-1.06E-09
-8.30E-09
-2.04E-09
Potassium nitrate, as N, at regional storehouse
kg
-0.011
-5.92E-03
-1.16E-05
-9.32E-09
-2.72E-07
-4.15E-07
-2.10E-07
Sodium Antimonate
kg
-0.002
?
?
?
?
?
?
Barium Carbonate
kg
-0.047
?
?
?
?
?
?
Strontium Carbonate
kg
-0.044
?
?
?
?
?
?
Limestone, milled, loose, at plant
kg
-0.0052
-8.32E-06
-6.66E-09
-1.33E-10
-1.66E-10
-5.30E-09
-1.68E-10
Zirconium Silicate
kg
-0.0072
?
?
?
?
?
?
Titanium dioxide, production mix, at plant
kg
-0.0011
-4.16E-04
-4.69E-07
-8.66E-10
-8.04E-09
-3.09E-08
-1.36E-08
Ceroxide
kg
-0.0008
?
?
?
?
?
?
Zinc for coating, at regional storage
kg
-0.00032
-2.70E-04
-7.68E-08
-2.60E-09
-2.98E-09
-3.42E-07
-3.20E-08
-4.24E-02
-3.05E-06
-4.61E-07
2.41E-07
-3.44E-05
-2.96E-06
TOTAL
Szenario 5 - lead recovery
Transport, lorry 32t, Cape Town to harbour
tkm
0.03
4.89E-04
4.92E-07
1.99E-09
1.73E-08
1.97E-07
2.00E-08
Transport, transoceanic freight ship, Cape Town to Antwerp
tkm
11.423
1.46E-02
1.20E-05
2.28E-08
8.13E-07
8.41E-07
2.57E-07
Transport, lorry 32t, Antwerp to Metallo
tkm
0.1
1.63E-03
1.64E-06
6.64E-09
5.77E-08
6.56E-07
6.68E-08
kg
-0.5
-6.75E-04
-1.04E-06
-2.61E-09
-1.01E-08
-1.45E-07
-1.35E-08
Natural gas, burned in industrial furnace >100kW
MJ
-0.129
-5.59E-04
-8.49E-07
-3.70E-10
-2.53E-09
-1.11E-08
-1.91E-09
kg
-0.011
-1.67E-04
-4.04E-07
-7.78E-10
-4.15E-09
-2.12E-08
-8.77E-09
kg
-0.056
-5.45E-02
-8.34E-06
-5.05E-07
-5.60E-07
-3.79E-05
-3.10E-06
Disposal, Pb-free CRT slag, to residual material landfill
kg
0.95174
1.11E-03
2.85E-07
6.34E-06
1.21E-08
1.63E-08
2.64E-04
-3.81E-02
3.78E-06
5.86E-06
3.23E-07
-3.64E-05
2.61E-04
TOTAL
Dominik Zumbuehl
115
October 2006
APPENDICES
Appendix 15: MAUT; questionnaire for the weighting of attributes carried out at the regional workshop at UCT in July 2006
WEIGHING OF CRITERIA
Imagine a new process for the recycling of Cape Town’s CRT screens would become available. Several
technologies and processes could be considered for the preferred and most viable recycling process. Below are
the main criteria listed which would have to be considered for the evaluation process in order to assess the
suitability and sustainability of any proposed recycling method.
How important are for you the consideration of:
weights
criteria
no
importance
little
importance
medium
importance
high
importance
very high
importance
Economic criteria
high profit
low operating costs
low capital costs
increased potential for local
economic growth
Environmental criteria
low use of process energy
(electricity, fuel, gas, ect.)
low fuel use for transportation
low use of freshwater
little emissions
minimum of waste volume to
landfill
low toxicity of remaining waste
Social criteria
creation of highly skilled jobs in
CTN
creation of jobs for the
previously unemployed in CTN
creation of jobs outside SA
low health & safety impacts
To which group of stakeholders does your company/organization belong to?
Supplier of IT equipment
Government
Environmental NGO
Consumer
Refurbisher
Scientists / consultants
Smelters / Refiners / Industry
Other group: _______________________
Date: _____________ Name: ___________________________
Email: _____________________ Phone: __________________
Dominik Zumbuehl
116
Position: _________________________
Mobile phone: ___________________
October 2006
APPENDICES
Appendix 16: Results of the weighting of the attributes carried out at the regional e-waste workshop at UCT in July 2006
System Specialist Holland
ICT Engineer Holland
Low operational costs for processing
2.94
3
3
3
4
4
2
3
4
1
2
1
4
4
3
3
3
2
Low capital costs
2.47
4
2
3
3
3
4
2
3
2
1
0
1
2
4
3
3
2
2
3.00
4
3
4
2
4
4
3
3
4
1
0
2
3
4
3
4
3
3
4
4
3
4
1
1
4
2
0
3
4
4
2
1
2
1
2
2
1
Government
3
4
Government
2
2
Government
3.40
Environmental
2
Smelter
4
Environmental NGO
2
Environmental NGO
4
3
Environmental NGO
4
4
technician Holland
3
2
Supplier
3
2
Waste Managment
3
2.06
Waste Management
3
High profit
Waste Management
2.71
Waste Management
Economic
Scientist
Consulting Engineer
Average
Scientist
Consultant
Attributes
1
2
2
4
3
3.06
2
3
4
3
3
4
3
3
2
3
3
2
3
4
3
4
3
3
3.24
3
3
4
3
4
4
4
3
3
3
3
2
3
3
3
4
3
3
3.18
3
3
3
3
4
4
3
3
3
3
2
3
3
3
3
4
4
3
3.25
3
2
4
3
4
4
4
2
3
3
4
2
4
3
4
3
4
3.47
4
3
3
3
4
4
4
4
4
3
4
2
4
4
3
4
2
4
Low toxicity of waste to landfill
3.47
4
2
3
3
4
4
4
4
4
3
4
2
4
4
3
4
3
4
3
4
4
3
3
4
3.30
Social
3
2
4
3
Creation of highly skilled jobs in Cape Town
2.22
3
3
3
1
3
4
2
4
1
3
3
0
1
2
2
1
2
2
Creation of jobs for the previously unemployed in Cape Town
3.22
4
3
3
2
4
4
3
4
4
3
3
0
4
4
3
4
3
3
1.50
1
2
2
1
0
4
1
3
2
2
2
3
0
0
1
1
1
1
3.22
3
3
3
3
4
4
2
2
4
3
4
1
4
4
3
4
4
3
Dominik Zumbuehl
117
October 2006
APPENDICES
Appendix 17: Offer for the shipping of a 40 feet container from Kuehne + Nagel, Cape Town.
P.O. BOX 4119, CAPE TOWN, 8000
REPUBLIC OF SOUTH AFRICA
Tel: +27 21 386 2677
Fax: +27 21 386 2765
Date
11/09/06
Validity
30 Days
Prime
11.5
Quotation References
QKF-609.012
FCL EXPORT COST ESTIMATE
TO:
FROM:
ORIGIN:
COMMODITY:
NO. OF PKGS:
WEIGHT: Tons
CUBES
SHIPPING MODE
ROUTING
Karen Faragher
Exw Wynberg
Glass Cullets
40'GP
23.500 kg
Seafreight
Cartage from Wynberg to Cape Town Port
Carrier Merchant Haulage Fee
Terminal Handling Charge
Cargo Dues
Bill of Lading
Courier Fees (per mailbag)
CTO Fee
Oceanfreight Cape Town to Antwerp
BAF
ATTENTION:
DATE:
Dominik Zumbuhl
11/09/2006
DESTINATION:
RATE OF EXCHANGE : USD
RATE OF EXCHANGE :
VALUE : $
VALUE : ZAR
MEASUREMENT
TARIFF HEADING
CFR Antwerp ( = Hamburg)
7.61
R50 000
Unknown
EXPORT CHARGES
1'260.00
1.00
1.00
407.00
1.00
1.00
1'109.00
1.00
1.00
1'599.39
1.00
1.00
185.00
1.00
1.00
350.00
1.00
1.00
110.00
1.00
1.00
2'300.00
7.61
1.00
402.00
7.61
1.00
CAPE TOWN (SUB-TOTAL)
1'260.00
407.00
1'109.00
1'599.39
185.00
350.00
110.00
17'503.00
3'059.22
25'582.61
DESTINATION CHARGES
Documentation
Communication
Agency Fee-4% (Min: R 750-00)
Facility Fee (Prime + 3%)
Insurance: Not Quoted
DESTINATION CHARGES (SUB TOTAL)
400.00
1.00
75.00
1.00
0.04
25'582.61
1.00
14.50
25'582.61
1.00
25'582.61
400.00
75.00
750.00
463.68
DELIVERED TOTAL
27'271.29
Account facility is available if required, additional finance fee will be charged on 30 days
Payment can be affected on call, weekly or fortnightly if you wish to reduce finance charge.
Estimates are based on specifications, dates and values etc., as submitted by clients and are calculated using current tariffs
and charges as per third party's notification.. Fees are based on the official tariff. We shall be entitled to revise the Estimate
should changes occur in specifications, rates, values, current exchange rates, sub-contractors and third party charges or any
other charges applicable to the handling of goods at time of shipment , with or without prior notice.
All Estimates submitted are subject to our Standard Trading Conditions, a copy of which is available on application.
Please confirm rates prior to shipment, estimate valid for 30 days only. If you are shipping any goods based on this estimate,
please forward a copy of this estimate with your shipping instructions.
Thank you for your attention.
KUEHNE & NAGEL (PTY) LTD
Karen Faragher Cpt VMS
Sales Assistant
Transport costs for a 40 feet container
Kuehne & Nagel Switzerland
Hamburg to Samsung Corning
€
transport
700
MAUT (german road levy)
92
custom
70
total
862
Dominik Zumbuehl
US $
899.29
118.19
89.92
1107
118
Metallo-Chimique
Antwerp to Metallo-Chimique
€
US $
total
270
346
October 2006
APPENDICES
Appendix 18: MAUT attribute vs. scenario matrix. The weights, the scales, the values of the attributes and the normalized and weighted utilities
Scenario 0
weighing
landfilling with trailer in the CMA
utility normalized
0.077
0.0369
0.91
0.077
0.1341
0.45
utility weighted
value
0.91
utility normalized
utility weighted
0.0362
lead recovery in Belgium
value
utility normalized
0.077
Sceanrio 5
utility weighted
value
0.91
utility weighted
0.0362
utility normalized
0.077
Scenario
Scenario
4 g
g 3b with crusher
p p
use in recycling concrete
CPT, CRT manufacturing in
bricks with previous crushing of Germany
value
0.91
Scenario 3a
blending with raw materials to
use in concrete bricks
utility weighted
0.0362
utility normalized
0.084
value
1.00
Scenario
g 3
use in recycling (RCA)
concrete bricks
utility weighted
0.0172
utility normalized
0.074
value
0.87
utility weighted
0.0444
utility normalized
$ / kg CRT
value
0.08
utility weighted
2.94
utility normalized
Scale / unit
value
weight normalized
Low net costs
weight stakeholders
Criteria
Scenario 1
Scenario
g 2
storage in the "Black Mountain" use in concrete rubble
lead mine in the Northern Cape production in CMA
0.038
0.2315
0.00
0.000
0.071
Investment costs
2.47
0.07
$
0
1.00
0.071
0
1.00
0.071
0
1.00
0.071
0
1.00
0.071
0
1.00
0.071
450000
0.65
0.046
1284700
0.00
0.000
0
1.00
Increased potential for local economic
growth
3.00
0.09
0, 0.25 0.5 , 0.75,
1
0.00
0.00
0.000
0.25
0.25
0.022
0.50
0.50
0.043
0.50
0.50
0.043
0.50
0.50
0.043
0.75
0.75
0.065
1.00
1.00
0.086
0.00
0.00
0.000
8.41
0.24
1.87
0.145
2.25
0.177
2.41
0.191
2.41
0.191
2.41
0.191
2.31
0.188
1.45
0.125
1.00
0.071
3.06
0.09
0.20
0.072
0.0184
0.00
0.000
-0.0035
0.36
0.132
-0.0049
0.38
0.140
0.0003
0.30
0.109
-0.0048
0.38
0.140
-0.0424
1.00
0.366
-0.0381
0.93
0.340
0
0
0
0
0
0.005
0.995
0.099
0
2.00
0.465
Economic utility
3.24
0.09
3.18
0.09
eco - indicator 99
0.0064
kg/ kg CRT
1
3.25
0.09
3.47
0.10
16.19
0.47
3.22
0.09
hours / kg CRT
2.22
0.06
hours / kg CRT
1.50
0.04
Environmental utility
Working hours for low-skilled / semiskilled in the CMA
Working hours for hihgly skilled in the
CMA
3.22
0.09
Social utility
10.17
0.29
TOTAL weights
34.77
1.00
0
0.000
0.20
0.072
1
0.100
1.00
0.100
0.0030
1.00
0.093
0.0000
0.00
0.000
hours / kg CRT
0.0000
0.00
0, 0.25 0.5 , 0.75,
1
0.50
1
0.100
1.36
0.232
0.0004
0.09
0.008
0.0000
0.00
0.000
0.000
0.0000
0.00
0.50
0.046
0.50
1.50
0.139
1
0.100
1.38
0.240
0.0003
0.03
0.003
0.0001
0.14
0.009
0.000
0.0000
0.00
0.50
0.046
0.75
0.59
0.054
1
0.100
1.30
0.209
0.0003
0.03
0.003
0.0001
0.14
0.009
0.000
0.0000
0.00
0.25
0.023
0.75
0.42
0.035
1
0.100
1.38
0.240
0.0003
0.03
0.003
0.0001
0.14
0.009
0.000
0.0000
0.00
0.25
0.023
0.75
0.42
0.035
1
0.100
1.93
0.440
0.0006
0.14
0.013
0.0018
0.57
0.052
0.0001
0.14
0.009
0.0006
1.00
0.064
0.0002
0.00
0.000
0.0000
0.00
0.000
0.0000
0.00
0.000
0.0003
1.00
0.000
0.043
0.0001
0.36
0.016
0.25
0.023
1.00
0.00
0.000
0.50
0.50
0.046
0.25
0.75
0.070
0.42
0.035
0.29
0.022
3.07
0.206
1.11
0.085
Total utility unweighed
3.570
3.837
4.192
4.215
4.130
3.977
6.516
4.042
Total utility unweighed, normalized
0.548
0.589
0.643
0.647
0.634
0.610
1.000
0.620
Total utility weighed
0.36
0.33
0.46
0.47
0.43
0.45
0.80
0.60
upper and lower error
Total utility weighed & normalized
Total utility unweighted
0.45
3.57
0.42
3.84
0.58
4.19
Upper and lower error unweighted
Dominik Zumbuehl
119
0.59
4.21
October 2006
0.55
4.13
0.57
3.98
1.00
6.52
0.75
4.04
APPENDICES
Appendix 19: MAUT values unweighted and weighted used in Figure 32. Also the lower and upper error margin used for the error bars are shown
S0
Landfill
S1
Lead m ine
S2
C oncrete
R ubble
Low net costs
0.873
1.000
0.911
0.911
0.911
Investm ent costs
1.000
1.000
1.000
1.000
1.000
0.000
1.873
0.197
0.000
0.197
1.000
0.000
0.000
0.500
1.500
3.570
0.548
0.705
0.535
0.250
2.250
0.000
1.000
1.000
0.087
0.000
0.000
0.500
0.587
3.837
0.589
0.386
0.192
0.500
2.411
0.360
1.000
1.360
0.029
0.142
0.000
0.250
0.420
4.192
0.643
0.266
0.089
0.500
2.411
0.383
1.000
1.383
0.029
0.142
0.000
0.250
0.420
4.215
0.647
0.417
0.240
0.074
0.071
0.000
0.145
0.072
0.000
0.072
0.093
0.000
0.000
0.046
0.139
0.356
0.447
0.057
0.043
0.084
0.071
0.022
0.177
0.000
0.100
0.100
0.008
0.000
0.000
0.046
0.054
0.331
0.416
0.034
0.018
0.077
0.071
0.043
0.191
0.132
0.100
0.232
0.003
0.009
0.000
0.023
0.035
0.458
0.575
0.067
0.052
Increased potential for local econom ic growth
econo m ic utility
H igh eco-indicator 99
M inim um of waste volum e to landfill
E n viro nm ental u tility
W orking hours for low-skilled / sem i-skilled in the C M A
W orking hours for hihgly skilled in the C M A
W orking hours outside S outh A frica
Low health and safety im pacts
S o cial u tility
T otal utility unweighted
T otal utility unweighted, norm alized
unweighted error, upper error
unweighted error, lower error
Low net costs
Investm ent costs
Increased potential for local econom ic growth
econo m ic utility
H igh eco-indicator 99
M inim um of waste volum e to landfill
E n viro nm ental u tility
W orking hours for low-skilled / sem i-skilled in the C M A
W orking hours for hihgly skilled in the C M A
W orking hours outside S outh A frica
Low health and safety im pacts
S o cial u tility
T otal utility weighted
T otal utility weighted, norm alized
weighted error upper error
weighted error lower error
Dominik Zumbuehl
120
S 3b
S3
S 3a
B rick with
R C A brick
C oncrete brick
crusher
M A U T values norm alized and unw eigh ted
M A U T values norm alized
0.077
0.071
0.043
0.191
0.140
0.100
0.240
0.003
0.009
0.000
0.023
0.035
0.466
0.586
0.052
0.037
October 2006
S4
C R T m anuf.
S5
Lead recovery
0.908
0.455
0.000
0.650
0.000
1.000
0.500
2.411
0.298
1.000
1.298
0.029
0.142
0.000
0.250
0.420
4.130
0.634
0.457
0.280
0.750
2.308
0.382
1.000
1.382
0.145
0.142
0.000
0.000
0.286
3.977
0.610
0.621
0.211
1.000
1.455
1.000
0.995
1.995
0.566
1.000
1.000
0.500
3.066
6.516
1.000
1.527
1.439
0.000
1.000
0.929
1.000
1.929
0.000
0.000
0.363
0.750
1.113
4.042
0.620
0.703
0.703
and w eighted
0.077
0.071
0.043
0.191
0.109
0.100
0.209
0.003
0.009
0.000
0.023
0.035
0.435
0.547
0.067
0.052
0.077
0.046
0.065
0.188
0.140
0.100
0.240
0.013
0.009
0.000
0.000
0.022
0.450
0.565
0.068
0.037
0.038
0.000
0.086
0.125
0.366
0.099
0.465
0.052
0.064
0.043
0.046
0.206
0.796
1.000
0.173
0.166
0.000
0.071
0.000
0.071
0.340
0.100
0.440
0.000
0.000
0.016
0.070
0.085
0.596
0.749
0.117
0.117

mass flow assessment

Transcription

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