A novel method for extraction of platinum from spent automotive catalyst: utilization of spent fluid catalytic cracking catalyst as flux.

A novel method of smelting of mixture of spent automotive catalyst (SAC) and spent fluid catalytic cracking catalyst (SFCC) to recover platinum and prepare glass slag was investigated. Compared to other metals collection processes for single hazardous waste solid, this method reduced the amount of fluxing materials addition and increased the processing types of hazardous solid waste simultaneously. The optimum SFCC addition, iron collector addition, Na2B2O4•10H2O addition, CaO/SiO2 mass ratio, temperature, and holding time for platinum recovery were 20, 11, 16 wt%, 0.6, 1550-1600°C, and 60 min, respectively. In this proposed combined process, more than 98% of platinum is efficiently recovered from SAC. Meanwhile, the concentration of platinum in glass slag was less than 7 g/t. The leaching characteristics of heavy metals in slag confirmed the obtained glass slag is a non-hazardous slag due to the low leaching rate of heavy metal ions. This article proposed an effective and environmentally friendly method for the recovery of platinum from SAC via a combined smelting process.