Multotec Process Equipment (Pty) Ltd reports that its Rhodax interparticle crusher is generating increasing interest in the platinum and diamond industries, in South Africa in particular. Capable of achieving high reduction ratios of up to 100:1 and high mineral liberation the latest installation, a Rhodax 1000 at Anglo American Platinum Corp. Ltd’s Polokwane smelter, was successfully commissioned earlier this year and is achieving in a single stage a performance comparable to that normally requiring a number of sequential crushing stages. The elimination of these multiple Comminution stages at Polokwane has translated into major savings in both capital outlay and operating costs.

The Rhodax inter-particle crusher works on the pressurised-bed fragmentation principle whereby the horizontal circular oscillation of the unit’s bowl subjects the material to a series of compression cycles. In the process, a bed of pressurised particles is formed and inter-particle breakage along grain boundaries is achieved within this bed.

At Polokwane, cast furnace slabs from the matte-casting machine are broken and passed over a 250 x 250mm aperture grizzly screen and then into a primary jaw crusher which produces a nominal –80mm product. This material is then fed into the Rhodax unit for final reduction to –2.4mm in closed circuit with a vibratory screen. The Rhodax is producing around 70 t/h of product at a gap setting of 30mm, but throughput can be substantially increased by opening the gap to 40mm, the nominal design opening.