case study: three springs talc

CASE STUDY: THREE SPRINGS TALC
Organisation
Imerys Talc
(formerly Luzenac Talc)
Site
Three Springs Talc Plant, WA
Year
2011
Application
Magnesium silicate
Challenge
ƒƒ Tight schedule and budget
ƒƒ Inhospitable arid weather
conditions
Solution
ƒƒ Turnkey installation of new
processing plant.
Results
ƒƒ Improved OPEX costs
ƒƒ Delivered on time and on budget
ƒƒ Incident free, zero harm installation
Imerys Talc operations started more than a hundred years ago and has
grown to become the world’s leading talc producer, employing 1,000 people
on five continents and supplying around 15 percent of global demand
throughout Australia, Austria, Belgium, Canada, France, Italy, Japan, Spain
and the United States.
PROJECT OVERVIEW
The Three Springs Talc site is the
largest talc deposit in Western
Australia, producing a full range
of high brightness, highly pure
microcrystalline
talc
grades
primarily for paint, paper, rubber
and technical ceramics markets.
Outotec, (then as TME), has been
a maintenance contractor for the
Three Springs Talc plant since 2003.
The original plant, built in 1968
was in a state of deterioration due
to age and the caustic effects of
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the hypersaline underground water
used at the plant.
With the original plant estimated
too costly to maintain and repair, in
addition to being built on the original
ore body, construction of a new,
state-of-the-art benefication plant
was elected as the most viable option.
The new plant would have production
capacity of 150,000 tonnes of high
grade ore per annum. This plant
would also be designed to comply
with best-in-class safety standards.
THE SCOPE
DISMANTLING OLD SITE
Given the long history and proven
track record at site, Outotec, (as
TME), was engaged in 2010 to
provide the turnkey installation
of the new processing plant.
The installation (from the top of
concrete), comprised the majority of
structural and mechanical works.
Whilst the majority of the corroded
plant works were disposed of,
approximately 30% was found to be
reusable and transported to the new
site. The dismantling of the old site,
review and stacking of equipment
was completed by Outotec in the
allocated two weeks. The steelwork
in the reusable components was less
corroded having been specified to a
more durable standard by Outotec in
the two years prior to the upgrade.
One of these items was a conveyor,
which, along with another two new
conveyors was previously detail
engineered and supplied by Outotec.
This included screening stations,
conveyors and sample tower; water
distribution piping and the provision
of earthwork excavation services,
detailed engineering of the radial
stacker and conveyor, and rebuilding
the
sample
crusher
station.
Additionally, the scope comprised
dismantling and disposal of the old
plant, installation of electric cabling
and upon completion, dry and wet
commissioning.
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SPECIALISED TEAM
Working 14 days on and 7 days
off, a team of up to 24 specialised,
accredited personnel were mobilized
to site. Following strict induction
procedures, a consistent team was
on-hand throughout the entire
installation and commissioning
period of four months.
STRUCTURAL SPECIFICATION
The saltwater used in the plant
is drawn from underground pits.
At seven times the salt content of
natural seawater, its caustic nature
is highly corrosive to steel structures
and components.
Prior to Outotec being contracted,
steelwork at the plant had just been
surface treated with paint and was
therefore unable to withstand the
saltwater conditions. Additionally,
joints were previously stitched,
allowing water penetration and
leading to subsequent rust and
deterioration. Taking hypersalinity
into consideration, Outotec’s design
recommended the steel structures
and components were galvanized
and seams were bolted then welded
to prevent water infusion. This design
ensured extended longevity and less
maintenance/repair requirements.
CHALLENGES
One of the most common elements
that affect exposed plants of this kind
is inhospitable weather conditions.
In Western Australia, sites are at risk
of multiple weather systems and
Imerys Talc was no exception with
dust storms causing intermittent
shut-downs and intense heat up to
49˚c. This however, is a matter of
course for the team who are used
to dealing with one extreme to the
other where climatic conditions are
concerned.
During the installation, Outotec
engineers worked proactively to
ensure adherence to stringent safety
regulations. One issue identified
during the project was with the slew
(stacker) conveyor. Originally the
conveyor was moved via its stub axle
by a wheel loader. This was deemed
a potential risk and an alternative
design was proposed. Outotec
and Imerys redesigned the wheel
mount and incorporated electrical
eurodrives for simple and safe
manoeuvrability.
COMMISSIONING
Over a four day period the entire
plant was rigorously checked
during the dry commissioning
procedure. The subsequent wet
commissioning lasted seven days
and highlighted minor issues which
were quickly identified and resolved,
demonstrating the advantage of
having a consistent team throughout
the project. Engineers revised
feed and flow rates on the chutes,
adjusted the samplers to ensure
the screens had the right throw and
redesigned one chute to prevent
potential issues.
SCHEDULED MAINTENANCE
SERVICES
Since the 2011 turnkey installation,
Outotec
has
provided
full
maintenance services at Imerys
Talc.
Additionally, further optimizations
at site have been implemented including installations of a larger
pump to manage increased flow and
redesigning the oversize chute.
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[email protected]
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