Selective Recovery of Vanadium by Oxy-carbochlorination of Basic Oxygen Furnace Slag: Experimental Study

Abstract

Vanadium is considered as a critical raw metal in EU whose industry consumes about 13% of the global vanadium production. This metal is mainly used for production of high strength and special steels, and advanced alloys for aerospace application. The vanadium raw material supply is today predominated by China, South Africa, and Russia. This work deals with the development of a chlorination process for vanadium extraction. In order to optimize the selective recovery of vanadium, various parameters (temperature, chlorine partial pressure, carbon content) were investigated. Two approaches for the selective recovery of vanadium are presented in this paper: the first approach consists of selective chlorination and vaporization of vanadium-chlorinated species, which can be then collected in condensates, while the second approach consists in the selective chlorination of vanadium contained in slag in a temperature range avoiding vaporization of vanadium-chlorinated species. Results show that under specific operating conditions, more than 95% of the vanadium content of the slag is recovered. Such specific conditions involve heat-treatment at 900 °C during 90 min of a slag/carbon mixture including less than 20% of carbon under air/chlorine atmosphere at a 0.45 partial pressure value. These promising results highlight the potential of the oxy-carbochlorination treatment for the selective recovery of vanadium from basic oxygen furnace (BOF) slags.