Ferroalloy Production from Spent Petroleum Catalysts by Reductive Smelting and Selective Oxidation Processes

Abstract

Solid spent catalysts from the hydroprocessing units of petroleum refining industries contain valuable metals of V, Ni, and Mo in appreciable concentration together with a significant amount of sulfur in an alumina supporting material. A recycling process for this resource has been developed and commercialized by reductive smelting and selective oxidation processes to recover these metals in the form of ferroalloys. The carbon saturated Fe–V–Ni–Mo melt recovered from the reductive smelting was oxidized to separate vanadium into a slag which can be processed for Fe–V alloy production. Then Fe–V and Fe–Ni–Mo alloys were successfully manufactured with high recovery ratios of over 90% and 95%, respectively.