Investigations into the Recovery of Platinum Group Minerals from the Platreef Ore of the Bushveld Complex of South Africa

Abstract

Anglo American Technical Solutions Research, PO Box 106, Crown Mines 2025, South Africa In the fl otation of platinum group minerals (PGMs) it has generally been assumed that they will behave similarly to base metal sulfi des and thus sulfi de reagent regimes are generally used in such fl otation plants. However the tellurides and arsenides of platinum and palladium contribute about 50% of the PGMs present in the Platreef ore, located in the northern limb of the Bushveld Complex of South Africa, and there is evidence of these minerals reporting to the fl otation tailings. The present investigation was aimed at studying the fl otation behaviour of tellurides, arsenides and sulfi des of Pt and Pd and relating these observations to their surface characteristics. Microfl otation, zeta potential determinations, time-of-fl ight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) analyses were used to study the synthesised samples after various treatments. It was shown that in almost all cases the addition of a typical sulfi de collector, sodium isobutyl xanthate (SIBX), increased the recovery of all the Pt and Pd minerals investigated but that the presence of copper sulfate widely used to activate sulfi de minerals caused the recoveries to decrease. These results may question the value of adding copper sulfate in the treatment of Platreef PGM-bearing ore.