Optimized Recovery of Platinum Group Metals (PGMs) From Spent Automotive Catalysts Via Industrial Steelmaking Slag Utilization

Abstract This study introduces a novel method for the recovery of platinum group metals (PGMs) from spent automotive catalysts (SACs) by utilizing steelmaking slag as an iron‐containing resource. Unlike previous approaches, this method eliminates the need for additional iron supplementation while achieving full utilization of silicon dioxide and calcium oxide components inherent in steelmaking slag, thereby significantly reduces slag generation through enhanced material recycling efficiency. Through thermodynamic calculations using FactSage software and experimental optimization, an optimal slag composition is determined: a CaO─SiO₂─Al₂O₃ mass ratio of 39:17:44 with a FeO content of 10 wt.%. Experimental results demonstrate that Platinum (Pt) and Palladium (Pd) capture efficiencies exceed 99%, while Rhodium (Rh) capture efficiency surpasses 92%. This method not only achieves high PGM recovery rates but also promotes the recycling of industrial solid waste, minimizing environmental impact. The study highlights the potential of utilizing steelmaking slag to capture PGMs from spent automotive catalysts, providing a sustainable solution for recycling valuable metals from waste automotive catalysts.