Characterisation and utilisation of vanadium-bearing titaniferous magnetite of Boula-Nausahi igneous complex, Orissa, India

Abstract

Background: Titanium and vanadium are elements of strategic and industrial importance. Unfortunately, in India, there is no ore deposit of titanium and vanadium. Though a part of the demand for titanium is being met by the beach placers, India has to depend largely on import to meet the demand. The titaniferous magnetite which contains significant amounts of titanium and some vanadium can be used as a source of titanium and vanadium. Though Indias' total reserve stands at 22 MT, at present, the titaniferous vanadiferous magnetite is not being used for extraction purposes because an economically viable extraction process has yet to be developed. Physical beneficiation to concentrate ilmenite, the principal mineral of titanium, from this ore is very difficult, as ilmenite is present in variable shapes and sizes. Thus, in spite of appreciable TiO2 content, this ore at present finds very little use. Hence an alternative method of plasma smelting is being tried to produce TiO2 rich slag (from which titanium can be extracted), pig iron and Fe-Ti-C composite (a highly valued product) from this hitherto unused ore. Methods: For the production of Ti-rich slag, fine magnetite powder with petroleum coke was directly smelted in a plasma reactor where, as for preparation of Fe-Ti-C composite, fine magnetite powder, thoroughly mixed with the requisite amount of activated charcoal, is pelletised and treated in argon plasma in a graphite crucible covered with a graphite lid. Results and conclusion: Mineralogical characterisation of the ore reveals the presence of magnetite and ilmenite besides other minerals such as spinel, hematite and goethite etc. The total TiO2 content of the ore (TiO(2)approximate to 13%) is mainly distributed in ilmenite and magnetite. As ilmenite is present in various shapes and sizes, beneficiation of ilmenite by physical means is very difficult. Plasma smelting of this ore has produced Ti-rich slag with 83% TiO2 content and Fe-Ti-C composite, a highly valued product.