A review on the metallurgical recycling of vanadium from slags: towards a sustainable vanadium production

The critical applications of vanadium in metallurgical field and the growth in commercialization of vanadium redox flow batteries (VRFB) have led to the increased demand of vanadium. It is thus important to ensure the sustainability of vanadium production. Vanadium bearing slags, the solid byproducts in iron-and steel-making plants, are the principal source of vanadium production, accounting for more than 69% of total vanadium in terms ofthe raw material types. Academic researches and engineering investigations have been addressed to develop such metallurgical processes for treating the vanadium bearing slags. This article presents a comprehensive review on the metallurgical treatments of vanadium bearing slags. The composition and phase/mineralogical characterization of vanadium bearing slags from various sources are given. Literature review shows that the vanadium bearing slags have been traditionally treated through the roasting assisted leaching with the recent efforts of integrating the state-of-the arts technologies in extractive metallurgy and developing direct leaching methodologies. Some promising methods are worth discussing and quite encouraging, and expected to be the future focuses of this area. Discussion also highlights the separation of vanadium from silica, phosphorus and chromium as the major interfering elements/metal in the leach solutions of vanadium slags. Recommendation is made for taking up future works in order to develop a sustainable metallurgical process for vanadium bearing slag. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).