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CASE STUDY: THREE SPRINGS TALC

Organisation Imerys Talc (formerly Luzenac Talc)

Site Three Springs Talc Plant, WA

Year 2011

Application Magnesium silicate

Challenge � Tight schedule and budget

� Inhospitable arid weather conditions

Solution � Turnkey installation of new processing plant.

Results � Improved OPEX costs

� Delivered on time and on budget

� 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

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

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 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.

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THE SCOPE

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.

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.

DISMANTLING OLD SITE

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.

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

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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.

If you would like more information, click here to contactpaul.ariti@outotec.com