High-value utilization of steel slag and red mud: Recovery of platinum from spent aluminum-based catalyst by pyrometallurgy

Aiming at the large consumption of flux in the process of pyrometallurgical smelting of spent aluminum-based catalysts, as well as the problems of difficulty in utilizing steel slag and red mud and low added value, a new process of co-smelting steel slag and red mud to capture platinum in spent aluminum-based catalysts was proposed, which provides a way to alleviate the hazards to the environment caused by the long-term accumulation of steel slag and red mud. The experimental results demonstrate that steel slag and red mud co-smelting effectively promotes the enrichment of Pt compared to single smelting methods. Under the conditions of the mass ratio of steel slag, red mud, borax, collector, carbon powder and spent catalyst of 1, 1.5, 1, 2, 0.5, and 1400 degrees C for 60 min, the capture rate of Pt is as high as 99.51 %, and the TFe in the smelting slag is as low as 2.99 wt%, indicating that efficient enrichment of Pt and Fe was realized. Wet weak magnetic separation successfully raised the platinum grade in the smelting slag from 1.36 g/t to 7.40 g/t, which is significantly higher than the mineral resource. The analysis shows that in the smelting process, platinum and iron are efficiently recovered, and rare metals such as rhenium and vanadium can be effectively enriched into the alloy through smelting, which is verified by EPMA and elemental analysis.