China Nonferrous Metallurgy

In this study, a combined iron capture and smelting-magnetic separation process was developed for the efficient recovery of platinum group metals (PGMs) from three-way catalysts (SACs) for waste vehicles. The optimized process parameters were determined by kilogram-level intermediate frequency furnace test: calcium oxide dosage of 40%, iron powder 14%, melting temperature of 1480℃, reaction time of 45min, the content of PGMs in the slag decreased to ＜30g/t, and the capture recovery rate reached 98.55%. For the remaining Fe₃O₄/Fe₃Si encapsulated PGMs particles in the slag, wet ball milling (particle size -0.1mm≥85%) combined with 0.14T magnetic field strength magnetic separation was used to obtain a concentrate yield of 1.3%, a PGMs content of ＜0.6g/t and a magnetic separation recovery rate of 97.7%. The total recovery rate of PGMs in the whole process exceeded 99.9%, and the magnetic enrichment of Fe₃O₄ and Fe₃Si particles was the core mechanism to achieve the deep recovery of PGMs. This process significantly improves the recovery efficiency of dispersed PGMs by iron capture and smelting technology, and provides a reliable technical solution for the large-scale regeneration of SAC secondary resources.