MechChem Africa March-April 2022

Rubber lining protects equipment against wear, but choose carefully

Mines are well aware of the significant cost savings that can be achieved by using rubber to increase the wear life of equipment. However, selecting the right product for the application is vital. Yatheen Budhu, product manager for rubber products, hoses and spools at Weir Minerals Africa, explains.

R ubber lining is a highly skilled pro- cess which – when done correctly with the correct type and thickness of rubber – can contribute consid- erably to the life and profitability of a plant. Perhaps the first issue to clarify is that there is no single lab test to provide a definitive answer, according toYatheenBudhu, product manager rubber products, hoses and spools at Weir Minerals Africa. “The industry standard test for rubber materials is the ISO 4649 dry abrasion test; however most wearing materials on a mine exist in a wet environment,” says Budhu. “For this reason, our Weir Minerals specialists developed amodified versionof the ISO4649 test, theWet AbrasionResistance Index (Wet ARI) test, which can be used for wet abrasion testing and is bettermatched towhat actually happens on the mine. “The test was developed specifically to replicate wet slurry wear conditions for elas- tomers and, over many years of testing, has become the standardbywhichwe canpredict the wear, not only of our rubber but also that of our competitors, which enables us to rank them side by side,” he explains. Yatheen Budhu makes the point that the samewearmaterial – such as slurries, sand or aggregate –will behave differently in varying conditions. For this reason, Weir Minerals’

Wear Testing Programme includes unique tests such as the Weir Coriolis test, which is particularly suited for mill pumps, and the Wet ARI test. “The range of options can seem over- whelming, but it is vital to select the right material for the job,” he emphasises. “Getting thiswrongmeans shorterwear life and raises the risk of premature failures that could lead to unplanned stoppages for maintenance,” he warns. Budhuhighlights the proven ability of nat- ural rubber to withstand abrasion, especially when its composition is close to the natural latex found in the rubber tree. This is where Weir Mineral’s innovative manufacturing process makes all the difference. “Each ad- ditional step in the production of rubber can damage itsmolecular chains and compromise the raw natural rubber’s excellent abrasion resistance,” he explains. “Through our unique liquidphasecompoundingprocess,weensure that our premiumrubber retains theessential properties of raw natural rubber and this al- lows it to deliver excellent wear life.” After almost acenturyof successful opera- tion inboth industrial andminingapplications, Linatex ® rubber is renownedfor reducing long termwear caused by fine particles, including thewet andabrasive conditions inmining. It is especially suitable for low angle applications

and its use includes the lining of pumps, pip- ing, hoses, chutes, valves and tanks. Where coarser materials are involved, Weir Minerals offers its Linard ® range of natural rubber compounds. This mate- rial combines high flexibility with excellent resistance to cutting, says Budhu. Linard ® compounds also resist deformation while providing anti-stick properties. “The choice of liner solutions goes beyond natural rubber to include synthetic rubbers,” he says. “The latter are formulated to be used where corrosive chemicals andhigh tempera- tures becomea factor.” For theseapplications, WeirMinerals developed its Linagard ® range of synthetic rubbers. These canwithstand the effects of leaching acids andhydrocarbons, as well as slurries which are hotter than 70 0 C. “Rubber lining is a highly skilled process which, when done correctly with the correct type and thickness of rubber, can contribute considerably to the life and profitability of a plant,” Budhu concludes. www.minerals.weir

Left: Linatex premium rubber retains the essential properties of raw natural rubber and delivers excellent wear life. Linatex rubber lining can be done at the Weir Minerals facilities or on a customer site. Right: The Linatex compounds are suitable for low-angle applications and are used in pumps, piping, hoses, chutes, valves and tanks.

22 ¦ MechChem Africa • March-April 2022