Integration of Unexplored Brazilian Fe-Ti-V Oxidized Ore for Vanadium Production in Established Industrial Processes

The reduction of hematite present in the oxidized Fe-Ti-V ore to magnetite was carried out to use this ore in existing processes. One of the first steps in obtaining vanadium is the magnetic separation process, and the oxidized ore exhibits no magnetism. The creation of a reducing atmosphere using air and charcoal at four temperatures (400–700°C) was studied, resulting in an economically viable industrial process. Efficient reduction of hematite to magnetite was achieved at 400°C within 3 h. ICP OES determined the percentage of V 0.40%. After reduction, XRD showed that the entire hematite fraction became magnetite. The experimental data for kinetics were the first-order model, obtaining the apparent activation energy value equal to 15.8 kJ mol⁻¹ and the pre-exponential coefficient equal to 0.49 min⁻¹. Magnetic separation in a low-intensity field, 1500 G, of the reduced ore generated two fractions, the magnetic fraction, which concentrated 90.7% of the V present in the oxidized Fe-Ti-V ore, and the non-magnetic fraction with ilmenite (FeTiO₃) and rutile (TiO₂). It is important that it does not form vanadium carbide (VC) during the reduction of the ore. Vanadium ore can now be used in the process already applied in industry.