Casthouse Safety Improvements – Boyne Smelters

Aluminium Cast House Technology – Eighth Australasian Conference –
Edited by P.R. Whiteley TMS (The Minerals, Metals & Materials Society), 2003
CASTHOUSE SAFETY IMPROVEMENTS –
BOYNE SMELTERS LIMITED
Ivo Musulin – Manager Metal Products
Boyne Smelters Limited
Handley Drive
Boyne Island, Queensland, 4680, Australia
Abstract
Boyne Smelters Limited produces in excess of 520,000 tonnes of saleable product per annum.
Products include continuously homogenised billet, alloyed T-Bar as well as ingot. Through a
number of different methods Boyne Smelters, including the Casthouse has been able to
dramatically reduce the injury rate. The injury rates for the Casthouse are documented in this
paper as well as examples of how the risk of injury has been reduced in specific areas.
The safety value endorsed by Comalco reads, as follow "If it's not safe, don't do it that way". The
purpose of this paper is to share some safety learning's across our industry.
1
Introduction
Boyne Smelters Limited first commenced production in 1982 utilising Sumitomo Cell
technology on what is referred to as Lines 1+2. A third potline was added (Line 3) in 1997, this
time utilising AP30 technology. The combination of these three potlines produces a combined
output that now exceeds 520,000 tonnes per annum. An aerial view of the Smelter is shown in
Figure 1.
Figure 1: The site layout is shown in an overhead shot of the smelter.
Molten metal is transferred to the casthouse via 7 tonne crucibles from Lines 1+2 and 9 tonne
crucibles from Line 3. Each crucible type is siphoned into one of the tilting furnaces in the
casthouse (Figure 2).
Figure 2: A crucible is being siphoned into a VDC furnace.
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The casthouse comprises of three ingot casters and two VDC pits. The ingot casters are each
supplied molten metal by 2 furnaces and primarily produce standard purity grade ingot. All
ingot facilities are set up to cast in a continuous mode. The two VDC pits produce both alloyed
T-Bar and billet, with all billet continuously homogenised. The VDC currently operates at a
rate in excess of 180,000 tonnes per annum (Figure 3).
Figure 3: Schematic of the casthouse layout at Boyne Smelters.
A fourth ingot caster will be commissioned in late 2003, which will add considerably to the
casthouse capacity (>150,000 tonnes per annum).
The casthouse operation includes the delivery of molten metal to the casthouse from reduction
lines through to all warehouse operations (excluding the wharf).
The paper is split into several sections. This includes:
1. Safety statistics.
2. Site safety initiatives particularly the one’s relating to modifying safety behaviour.
3. Safety improvement methodology through the crews using risk assessment tools such as
Job Safety Analysis.
4. Examples of safety improvements at the BSL casthouse.
5. Future safety improvements that are planned for the BSL casthouse.
Safety Statistics
The safety statistics at Boyne Smelters, including the casthouse has improved at a rapid rate
over the past five years. Figures 4 and 5 show the trend of lost time injuries (LTI’s) and
recordable injuries over the period January 1999 – May 2003. The injury data includes any
injury to a BSL employee, contractor (including capital works) and subcontractors. For the
casthouse, the same applies but it should be noted that all on-site activities related to loading of
vehicles for delivery to customers is included in the casthouse injury statistics. There was a
Lost Time injury in the casthouse in May 2003 (a knee strain from standing on a small piece of
aluminium the size of a cigarette) – this ended a record run of 405 days since the previous LTI.
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BSL Lost Time Injuries 1999 to 2003
(Total LWDI + RWDI)
Casthouse LTI's
20
18
16
14
12
10
8
6
4
2
0
10
8
6
4
2
Ja
nA 99
pr
-9
Ju 9
lO 99
ct
Ja 99
nA 00
pr
-0
Ju 0
lO 00
ct
Ja 00
n0
A 1
pr
-0
Ju 1
l-0
O 1
ct
Ja 01
nA 02
pr
-0
Ju 2
lO 02
ct
-0
Ja 2
nAp 03
r03
0
(a)
Figure 4: Lost time injuries 1999 – 2003 (May YTD) for (a) BSL whole
site (b) Casthouse.
Casthouse Recordable Injuries
BSL Recordable Injuries 1999 - 2003
30
12
25
10
8
20
6
15
4
10
2
5
99
-9
ay
M
Ja
n-
Ja
n99
Ap
r99
Ju
l-9
9
O
ct
-9
9
Ja
n00
Ap
r00
Ju
l-0
0
O
ct
-0
Ja 0
n01
Ap
r01
Ju
l-0
1
O
ct
-0
Ja 1
n02
Ap
r02
Ju
l-0
2
O
ct
-0
2
Ja
n03
Ap
r03
Se 9
p9
Ja 9
n00
M
ay
-0
Se 0
p0
Ja 0
n01
M
ay
-0
Se 1
p0
Ja 1
n02
M
ay
-0
Se 2
p0
Ja 2
n03
M
ay
-0
3
0
0
(a)
Figure 5: Recordable injuries (LTI’s + medical treatments) 1999-2003
(MayYTD) for (a) BSL whole site (b) Casthouse.
The question that obviously springs to mind is what has led to such a dramatic improvement.
The answer is – there is no single action that has led to such a change in performance. The
paper aims at providing some detail on what work has been done at BSL, particularly the
casthouse, which can hopefully help other operations in their drive to reduce the number and
severity of injuries. BSL as a site and the Casthouse hopes to learn from others on what they
have done to reduce injuries in their own operations as there is still much to learn from each
other in industry.
Behavioural Site Safety Initiatives
In the early 1990’s Comalco implemented the NOSA safety system, which had a high emphasis
on unsafe conditions. The systems are still in use at Comalco sites. This paper does not focus on
this system and the impact. After the NOSA safety system had been implemented, the focus
shifted towards looking at the impact of behavioural safety systems to complement the work
that had been done on unsafe conditions. There are some studies that indicate that up to 96% of
incidents and injuries could have been prevented through behaviour.
During the 1997/2000 period STOP for Supervision was rolled out at BSL. STOP for
Supervision is a Dupont behavioural safety system that focuses on interaction in the workplace.
The aim is to alter safety behaviour through interaction.
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There is a key belief that is driven through the behavioral safety approach – that is, all incidents
and injuries are preventable. Without this belief, sustained improvement will not occur and zero
injuries and incidents will not be achieved.
During the 2000/2001 period STOP for Employees was rolled out, which gave all employees
some skills (and comfort) to positively interact when safety observations were being conducted.
This has extended to employees now conducting safety observations on each other.
The period covering both the STOP for leadership and STOP for employees roll out also
corresponds to a significant reduction in the number of injuries as previously shown in figure 5.
Joint safety observations were introduced through 2001 and 2002,which were either:
→ A team comprising a cross section of the workforce that interacts in a work area viewing
and discussing with individuals how a task is performed, risks and controls. A common
outcome is a set of improvement recommendations (many quite simple, some with
greater complexity)
→ Reviews with Superintendents and crew leaders to set and establish standards in a
particular work area. Again with the potential to record and document a required
improvement through safety action databases – the current tool that is used to record
required improvements is through SAP R3.
During the 2001/2002 period, all employees were trained in performing Job Safety Analysis
(JSA).
→ A JSA is required when it is judged that a particular task that is not covered in
procedures or where there are changed circumstances that pose a greater risk or an
unknown level of risk.
The Importance of JSA’s
JSA’s are a very important tool that underpins many of the safety initiatives as well as helping
to shape the way many individuals consider the environment in which they work. Comalco’s
CEO Sam Walsh described the authority each individual at BSL and Comalco is empowered
with, that is “If it’s not safe don’t do it that way”. This philosophy fits well within the premise
of JSA’s – what is the risk and what is the control! If the risk is too high – then don’t do it that
way! The JSA hierarchy of controls is described in Figure 6.
ELIMINATION
SUBSTITUTION
ENGINEERING
CONTROLS
ADMINISTRATIVE
CONTROLS
PERSONAL PROTECTIVE
EQUIPMENT
Figure 6: Hierarchy of controls used in JSA the methodology.
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As mentioned the JSA methodology has many uses/benefits, here are some:
1. Non-routine tasks.
It is not possible to cover every task that could be required to be performed at a site with a
formal written procedure – this is because there is always the potential for non-routine tasks to
be required. Using the JSA methodology means that job steps are identified as well as the
associated risks and controls. If the risk is still too large for a particular job step, then there is
need for additional controls to further reduce risk. As well as dealing with non-routine tasks
there are also situations where a routine task (with an established procedure) has additional
risks brought about by a changed work environment. If the risk brought about by the changed
environment were high enough then a JSA would be required.
This tool is also important for contractor activities, which commonly has a high proportion of
non-routine activities. Figure 7 shows an extract from a JSA.
Job Safety Analysis Worksheet
JSA No
Task:
Area:
Equipment:
Date:
Participants:
SCOPE
Assumptions:
MP JSA 125
ELIMINATION
Stacking doubles behind G3 before removal to wharehouse
North end of G3 cast machine
SUBSTITUTION
Forklift
1/08/2002
Marty Price Frank Pintus David Breslin
ENGINEERING
CONTROLS
ADMINISTRATIVE
CONTROLS
To reduce forklift travel in run off passage
double bundle has been picked up from runoff
Job
Hazard
Existing Controls
C
Risk
>299
180 - 299
80 - 179
20 - 79
<20
Priority
Very High
High
Substantial
Moderate
Low
PERSONAL PROTECTIVE
EQUIPMENT
E
L
Risk Score Proposed Controls
C
E
L
1
500
safety barriers to
exclude people from
area y/ guard the area
1
10
1
10
500
exclude people from
area / guard the area
around laydown
1
10
1
10
Step
place d/bundle on
ground
remove bundles to
warehouse
Revised Risk
Score
dropped bundle
dropped bundle
awareness
awareness
50
50
10
10
1
Figure 7: JSA for stacking doubles behind Ingot Caster 3.
2. Improvement work.
The use of JSA’s is important when performing safety improvement work – particularly when
looking to involve a large proportion of the workforce. The casthouse at BSL has targeted
improvement through:
• Developing a high-risk task register through the involvement of the workforce in
prioritising key improvement requirements.
• Assigning a number of safety improvement initiatives to each crew (see Table 1 which
displays the issues being worked through by one of the ingot crews in the casthouse).
• Use of JSA methodology to review risks before and after proposed controls.
• Feedback improvements through centralised casthouse safety meetings attended by crew
safety representatives.
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Table 1: High risk task register Crew 3 Ingots
3. Other Benefits of JSA’s.
•
•
•
JSA’s help to imbed the culture of risk / control. Skills in risk identification are a key to
avoiding risk.
JSA’s are a key starting point in developing detailed procedures.
JSA’s offers a clear pathway to dealing with adhoc issuers where the job steps, risks and
controls can be considered before the task is carried out.
Do all Adhoc tasks need a JSA?
Not all tasks require such a formal process – the key is getting personnel to be able to
adequately assess risk and to make a decision on the tool to use based on the risk. Figure 8
below shows the risk rating process used which catagorises the risk into a severity category.
This determines whether a JSA is required.
Figure 8: Risk Rating matrix with designations of critical, high, medium and low.
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In many instances small jobs or relatively routine jobs that have a changed environment need to
have some level of risk assessment. If the risk is low, then a less formalized risk control process
can be used. This is commonly referred to as Take 2 or Take 5. The process asks individuals to:
1. Think through the task – e.g. what are the process steps.
2. Spot the hazard.
3. Assess the risk.
4. Make any necessary changes.
5. Perform the task safely.
This is an area that BSL will continue to work on, as there is much to be gained through a
workforce that is good in identifying risk, reviewing how to control the risk and not proceeding
until the pathway to achieving a safe outcome is clear.
Safety Philosophy
There are many different ways that safety improvement can take place. For sustainable
improvement, where the goal of zero is achieved I believe that the following steps need to occur.
This is depicted below in Figure 9. Whilst strong leadership is always required, there needs to
be a level of independence developed by all employees not to walk past and ignore any action
or situation that could cause harm to an individual. This is a difficult feat to achieve.
Safety is
achieved through
conformance
Safety is
improved
because people
raise and resolve
issues because
they don’t want
to be hurt.
Clear Standards
and procedures.
Top down
approach only.
Results in understanding of how to
perform a task safely. Needs
leadership to enforce adherence to
safety procedures and maintain
performance.
Risks raised and
resolved by all
personnel.
Will always require management
commitment, but results are more
sustainable as there is a higher level
of overall commitment to raising
and resolving issues throughout the
organisation. Not as leader
dependent as the above example
Strong bottom
up push as well.
Figure 9: Schematic displaying where the safety culture needs to move to achieve the goal of
zero injuries.
Fatality Potential
There are many ways that the linkage between incidents and injuries have traditionally been
described, below is one such example (Figure 10).
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Figure 10: A traditional depiction of the relationship between incidents and injuries.
In general the pyramid accurately describes the relationship between incidents and injuries.
Obviously as the number of incidents increases the potential for injuries and fatalities also
increases. The smaller the base (of incidents), the lower the chance of injury or fatality. There is
a flaw to this argument as it relates to fatalities. Simply, there are some incidents that if they
occur will invariably lead to a fatality. An example would be a fall from height where there is a
clear linkage between the height from which an individual falls and the probability of death.
Above a certain height the probability approaches 100%. With some hazard scenarios there will
not be a large incident base required to result in a fatality as depicted in Figure 10, rather
relatively few incidents would invariably lead to a fatality. For this reason potential fatality
scenarios need to be targeted in conjunction with other injury risk scenarios.
There are a number of ways that individuals can sustain an injury that will never be life
threatening but can easily lead to a lost time injury. Ergonomic issues that lead to sprains and
strains are a good example where the severity can result in the individual having long lasting
effects, but would never lead to a fatality. On the other hand a scenario such as a major
explosion will have a high fatality potential. Again, there is a need to have targeted activities at
both reducing the general rate of injuries as well as eliminating the potential for fatalities.
Rio Tinto safety standards have been implemented at BSL, which are focused towards fatality
elimination. The main ones relevant to a smelter are listed below.
1.
2.
3.
4.
5.
6.
7.
8.
Molten materials.
Vehicles and driving.
Isolation.
Confined spaces.
Electrical Safety.
Working at heights.
Change Management.
Contractor Safety Management.
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Isolation systems
The isolation system implemented at BSL is now common across all Comalco operations. The
being that if you are trained at one Comalco site you are able to use the system at another
Comalco site, with reduced chance of error due to lack of system familiarity as would occur by
running different systems throughout the organisation. To lead an isolation however an
individual needs to be trained as an isolation officer and deemed competent through training.
This competency-based training ensures the individual is familiar with the specific isolation
requirements that need to be performed as part of their role. Some key features of the isolation
system are shown in Figure 11.
The Casthouse has in excess of 250 isolation procedures related to specific tasks or areas (some
work areas have area based isolations that are required each time the area is entered). An
example of an isolation procedure is shown in Figure 12. There are of course more complex
procedures than the one shown in Figure 11, with up to 55 isolations for some of the major
shuts.
Multiple
Isolation
Lock.
Personal
Lock
Isolation
Officer
Lock.
Project
Manager
Lock.
A box designed to contain
The key(s) for the blue
Multiple Isolation Lock(s).
Isolation
Identification
Point
Caution
Out of
Service
Tag
Caution
Out of
Service
Tag
Caution
Restricted
Use Tag
Figure11: Critical features of the One Comalco Isolation System.
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Isolation
Statement
Figure 12: Isolation procedure for Main Crane Rail for the VDC Cranes
Specific Safety Improvements at the BSL Casthouse
The following section lists some specific improvements that have been made at the BSL
Casthouse over the past few years.
Ingot Molten metal explosions
The best example of recent work is the reduction in explosions on the ingot machines, which
numbered 29 in 1999 and was reduced to 1 in 2002 (and none year to date for 2003). The
major change has been the introduction of mould preheaters and the associated process logic –
this is shown in Figure 13 along with the data for the number of metal explosions in the ingot
area since 1999. There has been one metal explosion incident in the past 18 months, which was
resolved through the interrogation of the ingot Scada system as well as a thorough incident
investigation. This is described below.
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Metal Explosions During Ingot Casting
35
29
30
25
20
16
15
7
10
5
1
0
2002
2003
0
1999
2000
2001
Year
(a)
(b)
Figure 13: (a) Mould preheater used in an ingot casting machines and (b) Number of molten
metal explosions during ingot casting 1999-2003 YTD.
The last molten metal explosion on an ingot machine occurred was as a result of a water valve
that was replaced, but not calibrated correctly. The water valve is calibrated to ramp the water
flow gradually, allowing the water trough to fill sufficiently before full flow commences. Water
flows into the cast conveyor through a series of small inlets. If the trough is not full before full
water flow commences, the water inlets form jets of water, which allows spray to enter the
moulds. This event does not occur when the trough is sufficiently full.
This was discovered through the combination of a thorough incident investigation, combined
with Scada systems that provided the investigation with sufficient information to pin point the
root cause of the explosion. An example of the Scada screen used to resolve the issue is shown
in Figure 14. This discovery has led to the calibration procedures being updated to prevent a
recurrence.
Figure 14: Typical data from an Ingot Scada screen used to resolve a molten metal explosion.
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Ingot manual handling
There are numerous tasks within a casthouse that requires manual handling, one of the main
ones being manual handling of ingots. A number of steps have been taken to reduce the
incidence of ingot manual handling. These include:
Positioning of skips to avoid manual handling of reject ingots (see Figure 15) has been
improved. At times the ingot machines will continue to run for a short period producing reject
ingots in order to continue casting, whilst the issue is resolved. This is to avoid stopping a cast,
given that most casts are performed “back-to-back” (continuous casting).
(a)
(b)
Figure 15: reject skip arrangement for ingots released at (a) from the transfer conveyor (b)
underneath the cast conveyor.
There are also incidents where ingots do not drop out at the end of the cast conveyor and drop
out further beneath the cast conveyor. The above steps describe how to manage a situation,
ultimately the best solution to such a problem is to have all ingots released successfully! That
has been the attention of project work at BSL.
The work to reduce the number of ingots dropping out has involved the use of six sigma, which
is a statistical problem solving methodology now commonly used within Comalco operations.
The studies have shown that there is a clear linkage between variables such as casting
temperature, mould spray, mould condition as well as casting speed relative to the number of
ingots that drop out after the knock out end has been passed.
One of the improvements that will be implemented to further reduce the number of ingots that
drop out will be linking individual mould tracking to the Scada system to easily identify
specific moulds to occurrences of ingots not dropping out.
Contractor Management
Over the past 2 yrs there has been 5 lost time injuries in the casthouse – 4 of these have been
related to contractor activities. Of these 4 lost time injuries 3 have related to product transport
activities on site, whilst the other occurred during a furnace rebuild. Contractor management
has been a major issue. A dedicated casthouse contractor management team has handled the
management of contractors for maintenance and most capital work in the casthouse. For these
major shuts there is a rigorous demarcation process that controls the point and condition of
entry into this area. The condition of entry includes all the necessary inductions and training as
well as JSA’s for each of the tasks that will be performed.
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An example of the entry requirements and layout of such a shut is shown below in Figure 16.
There is a clear point of entry with safety plans and schedule clearly visible at the work area.
Figure 16: Controlled entry point for a furnace relining shut.
Future Improvements in Safety
There are many improvements that will come from procedural changes and also from improved
PPE, but when it comes to the hierarchy of controls it is obvious that elimination, substitution
or re-engineering generally provide a safer working environment, several of these are discussed
below.
Auto Ingot Casting
During 2004 BSL will implement a project titled auto ingot casting. The aim of the project is to
automate the cast start and the cast end sequence and eliminate the interaction with molten
metal at these points in the operation. This will be through the use of auto dams, self draining
launders with the cast start and cast end sequence performed away from molten metal in a
control room. Two people currently perform the cast start and end of cast sequence – which
represents ~40,000 interactions per annum. It is anticipated that the interaction will be reduced
by 95-100% of current levels.
Even with extensive personal protective equipment (wool viscose trousers, woollen casting
jacket, gloves and neck flap), improved procedures and some targeted capital, we have not yet
eliminated burns from our operation (see Figure 17 for burn injury levels from 1997 to 2003
YTD). Fortunately over the past 2yrs none of these burns have been first aid injuries and have
not resulted in lost time injuries, but there is always a potential with burns of infection and
increased injury severity. It is very much our aim to eliminate the potential for burns through
projects such as automated ingot casting.
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Number of burn injuries (including First Aid)
40
35
30
25
20
15
10
5
0
1997
1998
1999
2000
2001
2002
2003
YTD
Figure 17: Burn injuries from 1997 – 2003 (May YTD) across all casthouse activities (note
injuries include lost time, medical treatment and first aid injuries).
Auto T-Bar casting
Similar to Bell Bay VDC 4 casting system, BSL will implement the auto T-Bar casting concept
on VDC 1. This project is also well aligned with the auto ingot casting operation.
Vehicles
At the time of publication BSL were in the process of procuring furnace-tending vehicles. This
will be a great improvement in vehicle safety in many ways as there are numerous issues with
driving vehicles with a long boom through a casthouse (see Figure 18). The benefits in a tight
casthouse layout are, of course, greater.
Figure 18: Forklift arrangement with a boom for furnace tending.
Vehicle and pedestrian interactions have the potential for serious injury and of course fatality.
BSL is currently reviewing the risks and potential controls for these activities and how the
controls can be improved through a greater level of engineering controls. In addition there are
plans to automate the back end of the ingot casting machines and the eliminate forklifts (and
people) from this part of the operation.
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Summary
There are indeed many ways to improve safety and I’m sure that many in the industry keep
learning how much they don’t know on a regular basis! At the heart of safety improvement
there needs to be a care and concern for the well being of all employees. The approach to safety
improvement needs to be a balanced one. There is room for behavioural controls as well as
engineering controls. There is room for top down systems such as standards required for
activities that may result in fatalities as well as “bottom up” systems of crew based safety
improvements through the use of risk management principles (such as JSA’s).
There is always much to learn on safety and the journey is never over. I hope this helps others
with their own safety improvement programs and that writing this paper will lead to
suggestions from others on what they have done to improve casthouse safety.
Please remember that our goal for injuries should be zero and our people should believe that
this goal is achievable. To achieve this goal all our people and we need to believe this is
possible!
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