A Systematic Investigation of Microwave Heating in Oxidised Platinum Group Metal Ores

Abstract

Extraction of valuable Platinum Group Metals (PGM) in oxidised ores has been fraught with challenges due to their physio-chemical properties that hinder high/economic extraction rates. The aim of this study was to understand the potential of microwave heating to enhance mineral liberation in oxidized PGM ores (assumed to be represented by their respective metals) in microwave heating are studied using COMSOL Multiphysics computer simulations. The results showed that the ore constituents exhibited differential heating rates when mixed with a microwave absorbing additive, which is key to achieving thermal fracture within the ore to enhance mineral liberation. Also, an increase in microwave power resulted in an increase in the differential heating rate in the oxidized ores when an additive was present, suggesting that the presence of a microwave absorbing additive to the ores greatly improves the differential volumetric heating rate of oxidised ores. Of the elements tested, iron seems to have potential in increasing microwave heating in the oxidised ores when no additive is introduced. Copper was observed to be the one to first change state when heated thus giving a limit to the point at which the samples are heated. These findings suggest that microwave heating has the potential to be a viable technology for enhancing mineral liberation in oxidized PGM ores. Further research, such as A more detailed understanding of the size range of ore particles that are susceptible to differential heating at the micro-scale, is needed to optimize the microwave heating process and to develop new mineral processing techniques based on microwave heating. Overall, the study showed that microwave heating has the potential to be a versatile and effective technology for mineral liberation in oxidized PGM ores. Further research is needed to optimize the microwave heating process and to develop new mineral processing techniques based on microwave heating.