Processing of vanadium: a review

Vanadium is an important by-product that is used almost exclusively in ferrous and non-ferrous alloys due to its physical properties such as high tensile strength, hardness, and fatique resistance. Vanadium consumption in the iron and steel industry represents about 85% of the vanadium-bearing products produced worldwide. The ubiquitous vanadium is employed in a wide range of alloys in combination with iron, titanium, nickel, aluminum, chromium, and other metals for a diverse range of commercial applications extending from train rails, tool steels, catalysts, to aerospace. The global supply of vanadium originates from primary sources such as ore feedstock, concentrates, metallurgical slags, and petroleum residues. Vanadium-bearing host minerals consist of carnotite, mottramite, patronite, roscoelite, and vanadinite. Deposits of titaniferous magnetite, uraniferous sandstone, bauxite, phosphate rock, crude oils, oil shale and tar sands host vanadium. Apart from titanomagnetite and ilmenite ore deposits containing vanadium, slags from the ferrous industry are a major source of supply. At present, known world reserves are expected to supply the next century's needs. Vanadium-bearing materials are treated by means of several processes such as calcium reduction, roast/leach, solvent extraction and ion exchange to recover vanadium either as metal, ferrovanadium, vanadium pentoxide, or in the form of various chemicals. The recovery of aluminum and magnesium metal from smelters and refineries generates vanadium and associated compounds. Countries such as China, South Africa, and Russia are the largest world producers of ferrovanadium and its toxic oxides while about 40 other countries contribute smaller quantities in different forms for global consumption. Australia is poised to become a major player for this essential substance during the next decade. The supply and demand of vanadium products during the past 20 years has been relatively stable and subject to a gradual decline in delivered price. The paper describes established industrial processes for recovery of vanadium from sources such as raw ore and process reverts. The comprehensive condensation of pertinent facts is intended to provide a single reference source rather than the reader perusing many articles. (C) 2003 Elsevier Ltd. All rights reserved.