An Investigation into the pretreatment methods for the extraction of platinum (Pt) from platinum oxide ores

Abstract

Platinum (Pt) is known to be one of the rarest metals in the world.lt’s unique physical and catalytic properties make it largely valued across a number of various demand segments and technologies. The four main segments of Pt demand are automotive (30-40%), industrial (27-36)%, jewelry (23-30%), and investment ~10%. There has been a global Pt demand with automotive demand being on the highest rising to 16% in 2023 and predicted to grow in 2024. To meet the current rising demands, there has to be an increase in the production of platinum however, there has been a fast depletion of platinum group metals (PGMs) bearing sulfide ores which has activated interest in exploring the likelihood of the recovery of PGMs from near-surface oxidized PGM ores. In Zimbabwe and South Africa, there is an estimated resource of over 500MT of PGM oxides that is either unmined, mined, stockpiled, or discarded as overburdened waste. The recovery of these PGMs has shown to be difficult to process by conventional means as an alternative source to sustain the production of PGMs. Several attempts to process the oxidized ores via conventional hydrometallurgical methods by concentrator plants in Zimbabwe and South Africa have been made. The attempts saw some PGM values that fall within the floatable size range not being floated and successively reporting to the tailings. Attempts to process oxidized PGM ore have been made worldwide using different methods. This paper scrutinizes the different hydrometallurgical methods previously used to process the oxidized PGM ores and their recoveries, the challenges encountered and the research gaps to be considered for future research. Recommendations for future research will also be given based on current research techniques in the mineral processing field.