Distribution ratios of platinum group metals between the Al ₂O₃-CaO-SiO₂ Slag and molten iron at 1873K

Gasoline vehicles are fitted with three-way catalytic converters containing platinum group metals (PGMs) such as platinum, palladium and rhodium. In future, many countries will also adopt stringent vehicle emission regulations that in effect require the three-way automotive catalytic converters. Therefore recovery process of PGMs from the autocatalyst is very important. PGMs recycling process, which is used molten iron as metallic solvent to concentrate the PGM from the three-way automotive catalytic converters, has been operated. A fundamental study of the recycling process was carried out to recover the PGMs from the three-way autocatalyst. Distribution ratios of platinum, palladium and rhodium between the Al₂O₃-CaO-SiO₂ slag and molten iron or carbon saturated iron were measured at 1873 K. Distribution ratios of PGMs between the slag and the liquid iron and the carbon saturated molten iron were from 1×10^-6 to 5×10^-5. Based on the distribution ratios, recovery of platinum, palladium and rhodium using the molten iron as metallic solvent is determined at 1873 K. We found that PGMs is enriched to the molten iron or the carbon saturated iron and the slag loss of PGMs is negligible small.