Abstract
—Flotation is a very crucial downstream processing stage in the Platinum Group Metals (PGMs) value chain, as it affects the preceding downstream processes should economic recoveries not be met. This process takes advantage of separating minerals based on their hydrophobicity or hydrophilicity. The flotation of oxidised PGMs has been an area of concern over the years, as conventional methods have failed to achieve economic recoveries. Early efforts to process oxidized PGM ores using conventional flotation methods yielded poor recoveries, typically below 50%, making commercial exploitation challenging. Thus, the effect of co-collectors in the flotation of oxidised PGM ore was investigated by assessing their impact on flotation performance, recovery, and selectivity. The experimental setup was designed using Response Surface Methodology (RSM). Due to the nature of the ore source, the sample was first preconcentrated using the shaking table to reduce the chromite content before flotation. The parameters under study for the flotation process were the dosage of the collector, the depressant, and the effect of time. Based on the optimal conditions determined through RSM, a kinetic study was conducted under those conditions to investigate the flotation rate mechanisms of oxidised PGMs, which are known to exhibit both fast and slow-floating particle behavior. The optimal conditions according to RSM were found to be at pH 8 and dosages of 300 g/t,80 g/t for both SIBX and Senkol 1238, respectively. Under these conditions, a maximum grade of 3.9058 g/t and a recovery of 48.43% for 3PGE+Au was achieved. The flotation kinetics study indicated that all 3PGE+Au components followed the modified Kelsall model.