A review on vanadium extraction techniques from major vanadium-containing resources

The critical role of vanadium in metallurgy and the increasing commercialization of vanadium redox flow batteries have contributed to a rise in market demand for vanadium, emphasizing the need to ensure the sustainability of vanadium production. Converter vanadium slag and stone coal, generated during the smelting process of vanadium–titanium magnetite, serve as primary raw materials for vanadium extraction. This paper reviews the process mineralogy of converter vanadium slag and stone coal, encompassing the chemical and physical phase compositions of the raw materials and the state of vanadium occurrence. The aim is to establish a theoretical foundation for the mechanistic study of the vanadium extraction techniques and to provide a reference for the optimization of the process afterward. This paper systematically summarizes the current vanadium extraction technology from converter vanadium slag, covering roasting, direct leaching, sub-molten salt method, and the technology and research status of vanadium extraction from stone coal. Most importantly, it identifies key issues in the current vanadium extraction techniques and challenges faced in actual production, based on the analysis of the current vanadium extraction process and mechanism research. The forward feasibility and prospects for the development of vanadium extraction technology are outlined.