Mineralogical reconstruction of Titanium-Vanadium hematite and magnetic separation mechanism of titanium and iron minerals

In this paper, magnetization roasting - low-intensity magnetic separation was performed on a pre-concentration concentrate obtained from an Australian hematite containing titanium and vanadium to realize the separation of titanium and vanadium. The results showed that an iron concentrate with TFe (total iron) grade of 58.71%, iron recovery of 86.72% and V₂O₅ grade of 1.00%, V₂O₅ recovery of 93.97% could be obtained under the optimum roasting conditions (roasting temperature of 580 °C, total gas-flow rate of 1.44 m³/h, CO concentrate of 30%, roasting time of 20 min), meanwhile the iron tailings (i.e., TiO₂ concentrate) with TiO₂ grade of 43.76%, TiO₂ recovery of 63.42% was obtained. XRD analysis, phase iron chemical analysis, and magnetic analysis were conducted on the raw sample and the roasted products. The results showed that after magnetization roasting, the hematite and limonite in raw sample were transformed into magnetite with strong magnetism, and the vanadium hematite of hexagonal system was transformed into vanadium magnetite of equiaxed system. As the weakly magnetic ilmenite does not participate in the reaction during reduction roasting, the separation of ilmenite and vanadium can be easily achieved via magnetic separation.