Recycling of platinum-group metals from spent automotive catalysts by smelting

The necessity, economics, and sustainability of recycling platinum-group metals (PGMs) from spent automotive catalysts (SAC) have stimulated the emergence of many relevant treatment technologies. Considering the industrial feasibility and recovery efficiency of smelting, this study provided an in-depth review of smelting technologies for recovering PGMs from SAC. Based on the understanding of the characteristics and deactivation mechanisms of automotive catalysts, the effects of various factors on the performance of slagging, collection and separation of PGMs and the features of main smelting processes involving using lead, iron, copper, matte, and wastes as collectors of the metals were reviewed and discussed. The measures for improving the recovery efficiency of PGMs by smelting were proposed from the perspectives of selection of additives and collectors, regulation of slag properties, and optimization of smelting conditions, introduction of microwave field, etc. In addition, the solutions for reducing the dependence of catalysts on PGMs were offered to further resolve the conflict between supply and demand of PGMs.