Processing of Platinum Group Metals: From Primary Ores to Secondary Resources and Sustainable Recovery Strategies

Platinum group metals (PGMs), including Pt, Pd, Rh, Ir, Ru, and Os, are essential materials used in catalysis, electronics, and energy technologies. Their extraction from both primary ores and secondary sources faces challenges due to complex mineralogy, low grades, and high chemical stability. This critical review explores current processing methods for PGMs, such as pyrometallurgical concentration, hydrometallurgical extraction, and advanced separation techniques. Special focus is placed on leaching mechanisms, solvent extraction, ion exchange, and innovative technologies like bioleaching and deep eutectic solvents. The integration of primary and secondary processing, particularly from spent catalysts and electronic waste, is evaluated in terms of efficiency, selectivity, and environmental impact. Key research gaps are identified in multi-metal separation, reagent selectivity, and process improvements, offering a roadmap for sustainable and efficient PGM recovery.