Sandvik Mining South Africa placed an order with Multotec to supply two in-line overbelt magnets for the removal of tramp iron at Sasol’s new Thubelisha coal mine in Secunda. “This order was for the supply and installation of our biggest overbelt magnets – 33 t oil cooled units,” Ernst Maritz, General Manager: solid liquid and magnetic separation at Multotec, says. “The two magnets, each 2.4 m wide, will reduce the risk of tramp iron being conveyed into downstream coal processing equipment.”

In specifying the largest overbelt magnet in the range, the Multotec team considered variables such as conveyor belt speed and size, burden depth, properties of the load on the belt and the size of the product being conveyed.

The magnets, which are suspended over the conveyor on gantries for easy removal for maintenance purposes, feature an automatic belt-driven self-cleaning mechanism that dumps the tramp iron into collection bins located on the side of the conveyor. Tramp iron traditionally removed from coal carrying conveyors includes sections of continuous mine core breaker teeth, conveyor belt idlers, belt joints, wire, roof bolts, metal plates, slings, picks and pick cases, cable hooks, expanded metal, tools and tin cans.

Multotec is one of the largest suppliers of overbelt magnets in South Africa. The company is in the final stages of the development of a flameproof air-cooled overbelt magnet for underground tramp iron removal. The company will embark on the manufacture of this innovative new product as soon as it receives the required certification confirming that it complies with SANS 10108 Edition 5, which refers to flameproof equipment used underground.