A common misconception in the mining industry is that it is too expensive to fabricate equipment from stainless steel.
It has become the status quo to use mild or carbon steels due to the lower initial price tag, but there are several reasons why the use of stainless steel delivers more cost benefits in the long run.
The nature of mining means equipment is inevitably exposed to the most harsh and abrasive environment of any workplace.
Stainless steel is much more suited to this type of environment due to its increased corrosion resistance, higher strength and durability, which drastically extends the useful life of the equipment.
Therefore, its use delivers cost savings in many mining applications, especially where chemical resistance is required, such as in copper mining, and where a longer mine life is applicable.
While the initial cost of stainless steel can occasionally be more expensive than carbon or mild steel, it can end up being more cost-effective when fabrication time is taken into account.
In most cases, carbon steel involves three processes not only relating to the steel itself but also to the required rubber lining and painting — to combat corrosion and abrasion — while stainless steel only requires a single process. This can improve fabrication and installation time, as well as the longevity of the product.
Stainless Steel Champions
TFG Group is not only an industry leader in the fabrication of stainless steel equipment for the resources industry.
With its national footprint, the Australian company has also become an advocate for the use of stainless steel across a wide range of industries in Australia.
Australian Mining Review spoke to several of the company’s management team to find out more about its operations and products.
Established in 1995, TFG delivers excellence in metal fabrication, mechanical installation and maintenance services within the agricultural, brewing, commercial, dairy, food and beverage, industrial, pharmaceutical and water industries.
TFG is an accredited fabricator and member of the Australian Stainless Steel Development Association.
It won the ASSDA Fabricator of the Year award in 2018 for the greenfield mechanical installation expansion at Fuchs Lubricants’ world class facility in Beresfield near Newcastle in NSW.
The 12-month installation project included nine kilometres of 304 stainless steel sanitary grade tube, one kilometre of stainless steel pipe, multiple tanks and the specialised fabrication of a blending platform and pipe racks to move specialised oils around the 25,000m2 factory.
TFG’s engineering team completed 3D drawings before designing, fabricating and installing the 35t specialised blending platform and pipe racks for the lubricant plant.
A point of difference was the use of stainless steel tube. A plant of this kind would traditionally be built with mild steel pipes.
After winning the award, TFG was invited by ASSDA to give a presentation in Brisbane about the benefits of using stainless steel, which is one of the largest growth industries of the last 100 years.
Since 1950, worldwide production has expanded from about 1mt to more than 50mt in 2018 at a growth rate of 5.5% year-on-year while the market for stainless steel in Australia has more than doubled in 30 years, according ASSDA.
TFG managing director Justin Anderson said TFG was the first fabrication and installation company to be invited by ASSDA to give a presentation at their awards in 2019.
“ASSDA is set up to promote the use of stainless steel in Australian industry so we are very well connected with them and happy to work with them to promote the use of stainless steel in all industries,” Justin said.
He said its use in the mining industry had grown over the last decade as companies look for ways to reduce costs, increase production time and extend the useful life of equipment.
“The price of stainless steel has dropped significantly over the last ten years so it has become more competitive than rubber lined carbon steel,” Justin said.
“Where it was often cost prohibitive to apply stainless steel in the mining setting ten years ago, it has now become more viable.
“Overall, the trend we’re seeing is that progressive mining companies are choosing materials based on overall life-cycle cost rather than upfront expenditure.”
Companies are also under pressure to meet sustainability and renewable targets, particularly with their water resources.
TFG has extensive experience in water treatment, renewable energy and filtration, which constitutes the largest application of stainless steel in the mining industry.
TFG specialises in the fabrication, installation and maintenance of the infrastructure required to filter water back to a potable state.
TFG’s capabilities in water treatment includes:
- Elution Skids
- Micro and Carbon Filtration Systems
- Potable Tanks & Pipework
- Platforms and Access Equipment
- Pump Rooms
- Reverse Osmosis Systems
- RO and MF Transportable Skids
- Tanks and Storage Vessels
- Pit Covers
- Ladders and Tank Canopies
- Pipe Spooling
Other Mining Applications
Gold stripping: Stainless steel electrowinning cells used in the gold stripping process at the end of an elution circuit with the addition of runner lining to provide insulation.
Conveyor rollers: Stainless steel conveyor rollers are used where there are mag-belts on conveyors, which remove anything magnetic. Thus the use of rollers made from stainless steel, which is not magnetic.
Reclaimer buckets and launders: RC3 reclaimer buckets, built using 3CR12 Sandvik proprietary material, have a high wear capacity, the highest corrosion resistance and are built to AS1554 Standards.
Screening mesh: A rubber screen is sometimes used but stainless steel is advantageous if the screening solution is made from destructive chemicals.
Tanks and vessels: Depending on what liquid is being held, stainless steel offers high corrosion resistance for the storage of specific chemicals including acids.
Duplex Stainless Steel
Another benefit of stainless steel is the flexibility in product selection due to the various grades, plus the ability to use Duplex products with a higher chromium content, thus increasing its corrosion resistance, depending on the application.
Sandvik offers highly rated duplex products, which offer excellent resistance to corrosion, resulting in significantly more uptime than carbon and conventional stainless steels.
Higher mechanical strength allows for lighter constructions, a more compact system design and less welding.
Sandvik offers several tubular grades of duplex stainless steel contributing to product advantages in a wide range of applications.
These include SAF™ 2707 HD hyper-duplex stainless steel, which has a very high resistance to chloride corrosion, combined with high mechanical strength.
It can also serve as a competitive alternative to expensive nickel alloys.
Sandvik SAF 3207™ is a hyper-duplex stainless steel suited for highly corrosive conditions and where a very high mechanical strength is required, making it ideal for use in deep-water umbilicals and a range of other oil and gas applications.
Santos Waddy Brae Minesite
In a world first, TFG fabricated the water treatment module for Veolia’s Santos Waddy Brae Minesite in Queensland within a tight three-month time frame.
The module combined microfiltration and reverse osmosis carbon filtration systems on the same transportable skid, making it capable of converting 30,000l of waste-water into potable water every hour.
TFG, which was chosen for the project due to its previous experience with complex filtration projects, used Sandvik SAF 2205 duplex stainless steel for all high-pressure pipework and the entire module fit on a 12-metre skid for ease of assembly.
The use of the higher grade of steel, as opposed to a standard 316 grade, prevented the skid from corroding and therefore ensured a life span of about 50 years instead of five years.
The use of a rubber-lined carbon tank had led to corrosion issues at the Paraburdoo iron ore mine in the Pilbara.
TFG fabricated a stainless steel replacement 44,000l water tank in 2020 after working closely with the client to meet their objectives within a tight schedule. The tank was designed, fabricated, tested and delivered to site with zero cost overruns and no safety incidents.
Designed to API 650 construction, the external welds were strip polished and the internal welds were pickled using a Hydrofluoric solution.
Port Kembla Coal
TFG Group fabricated 15 reclaimer buckets for the Port Kembla Coal Terminal in Wollongong, NSW. The job required the design of an initial ‘jig’ to ensure a universal fit across all buckets to enable precise assembly, welding and machining of the initial bucket to ensure the others were delivered on time.
The buckets were fabricated with 3CR12 Sandvik proprietary material, a high wear capacity and to AS1554 Standards for all welding and testing.
Consultancy Engineers EPS awarded TFG Group contracts to supply and fabricate several skid mounted Elution Circuit Heating packages for a number of national and international gold mines.
The skids were made from a galvanised frame structure and contained process equipment made to custom isometric drawing specifications, pre-spooled and fitted fabricated pipe spooling and specific flue equipment for each skid.
TFG project-managed the process of supplying insulation of the heat circuit pipe spools, fitted electrical instrumentation, flanges, flow meters, heat exchangers and associated specialised installation of pumps, tanks, tubing and valves. It also performed testing on its premises before transportation to site for the end client.
TFG Group offers a wide range of specially engineered products and equipment for the resources industry and its range of products have been used on mine sites throughout Australia.
TFG’s experienced team can deliver replacement parts, provide damage repair, upgrades or newly fabricated components as well as offering products for the safe and efficient storage, processing and handling of chemicals.
The company is able to deliver a safe, reliable, fit for purpose solution for a wide range of fabrication, rectification, testing and corrosion control requirements for green and brownfield sites.
TFG has experienced success in the manufacture and fabrication of buffer tanks, chemical tanks and pipe work, conveyor screens, drive shaft and belt guards, dust housings, elution skids, end chutes, mounting brackets, pressure vessels, wear plates and more.
Pipe Verse Tube
TFG’s background in the pharmaceutical, food and beverage industry means quality control is a pillar of the company’s success.
TFG business development and sales director Tom Moultrie said a major benefit of using stainless steel tube over pipe is it is more hygienic.
He said the preparation time is also reduced due to stainless steel requiring a single weld rather than multiple welds needed for schedule pipe.
The stainless steel is also longer lasting due to passivation which brings chromium to the surface for enhanced protection against corrosion.
Tom said an overseas client had used scheduled pipe made from carbon steel in their compressed air lines, which had corroded due to residual moisture in the lines.
‘’We ended up replacing the carbon steel pipe with stainless steel due to corrosion,’’ he said.
“The ‘’short-sighted’’ decision to use carbon steel because it was cheaper initially actually ended up costing them more in the long run.”
TFG Group also offers a wide range of specially engineered products and services for desalination plants, water treatment facilities and state water assets.
TFG is accredited to both Sydney Water and the Water Corporation of WA, as well as various water authorities in Queensland. With its national footprint, quality assurance and a safety-first approach, the company has the experience and capability to carry out a broad range of jobs.
TFG was awarded the contract to install all pipe supports, piping, valves and associated instruments to all recharge spooling for the $125m Beenyup Advanced Water Recycling Plant in the northern Perth suburb of Craigie.
The project is the key component of Australia’s first full-scale Groundwater Replenishment Scheme, which boosted much needed drinking water supplies in WA.
Operated by the Water Corporation, the plant now has the capacity to recharge up to 14 billion litres of recycled water into groundwater supplies every year.
That will soon be doubled to 28b litres a year through an expansion project being rolled out this year.
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