Hard to handle minerals

Record rainfalls across Australasia and Asia pose sticky production and profit challenges to mines, ports, power stations and transport.

Record rainfalls across Australasia, Asia, and elsewhere are posing major challenges to materials handling, production, and profits at a time of high prices for coal and strong demand for high-value minerals including iron ore, lithium, nickel, gold, and others. While urban centres such as Sydney have attracted headlines with its highest rainfall ever recorded in 2022 – more than two metres worth, months before the year was over – the problem has also been equally dire in major coal areas of the Eastern States and major mines and ports in the West and North. New Zealand, Indonesia, Vietnam, and India have also been saturated and flooded.

“All this moisture and long-term rain makes coal sticky, heavier, and harder to handle for the mines, as well as for the organisations transporting it and the ports and power stations where it arrives. Ceaseless rain also causes major disruptions – even Force Majeure events – at iron ore and other mineral mines,” said engineering plastics specialist Laurie Green, Managing Director of Cut To Size Plastics.

Cut To Size fabricates to individual requirements its globally proven low-friction Wearex UHMWPE (ultra-high molecular weight polyethylene) chute, bin, truck, rail, and ship loader linings that assist product flow and avoid blockages and the OH&S risks and downtime that go with them.

“When using wet or hard-to-handle coal, for example, the use of high molecular weight polyethylene plastic chute liners has become a number one method to improve the flowability of coal chutes, said Green. The same benefits apply to harder mineral ores, where clogging, production hang-ups, and loading and unloading issues can cause costly production interruptions and OH&S issues.

“This climate change issue is not likely to go away any time soon, and high-flow liners are one way of effecting major improvements promptly,” said Green, whose company also advises on the important issue of liner attachment, which can considerably extend durability standards that are already excellent.

Working with miners, transport operators, ports, and stockpilers, Cut To Size custom-engineers tough plastics formulated specifically for the mining industry and the minerals and challenges it faces. The new plastics are based on the globally proven Wearex™ UHMWPE for the toughest wear prevention and flow jobs, complemented where suitable with high-density polyethylene, HDPE. HDPE is often used as geotextile protective liners that promote flow while stopping clogging and waste dropping to the ground where waste has to be laboriously cleared and reprocessed.

Both plastics are finding applications in static and mobile plant, including as liners in trucks, bins, and chutes where wear and energy consumption are issues, and where companies wish to eliminate OH&S hazards involved in clearing dense and heavy potential blockages.

“Often the combined use of Wearex and HDPE provides the best combination of wear-resistance and cost-efficiency,” said Green, but Cut To Size is putting special effort into advanced UHMWPE formulations for the most intractable loads.

“It is certainly not one size fits all. The process of engineering plastic selection and formulation is a scientifically demanding business in which we rely on our own expertise supported by some of the world’s leading suppliers of product.”

“One of the big problems is the variability of throughput. Good operators can account for specific moisture content or rock content coming down the line or going on the trucks, but the material coming through may not be consistent. One lot will be wetter than the next, the next lot will have more rock and so on. So they have to address the problem holistically, and this sometimes involves lining chute systems and truck trays with materials that give high slip performance right across the spectrum,” added Green, who’s had decades of experience in adapting engineering plastics to solve particular problems.

Green added that in addition to advanced UHMWPE formulations, HDPE materials can provide cost-efficient solutions to some mining issues. They have excellent impact strength and can be easily formed and machined to tray and bin liner applications using conventional equipment. Frequently used as geotextile and protective liners, HDPE is available in a range of sheet sizes.

UHMWPE resin has a molecular weight range of three to six million, compared to 300,000 to 500,000 for high molecular weight (HMW) resins. That difference is what ensures that this material is strong enough to withstand abrasion and impact better than lower level products.

Cut To Size works closely with individual clients utilising a team of technically qualified staff to offer a full material selection and installation service. “Cut To Size has broad experience – extending over multiple industries for decades – in engineering plastics to suit wear prevention applications, so we can complement product from globally recognised suppliers, with local expertise,” said Green. cuttosize.com.au