Separation and recovery of iron and titanium from oxidized vanadium titano-magnetite by gas-based reduction roasting and magnetic separation

Gas-based reduction roasting magnetic separation process was conducted to separate and recover iron and titanium from oxidized vanadium titano-magnetite (VTM). The effects of reduction temperature, gas composition, reduction time, grinding fineness, and magnetic field intensity on the efficiency of Fe-Ti separation were investigated. Under the condition of reduction temperature of 1050 °C, reduction time of 120 min and gas composition of P(H2)/P(H2 + CO) = 0.72, a magnetic product containing 84.5 wt.% total iron with Fe recovery of 93.67% and a non-magnetic product containing 43.46 wt.% TiO2 with the TiO2 recovery of 67.12% were obtained. The efficiency of Fe-Ti separation shows a rise first followed by a decline with the increases of P(H2)/P(H2 + CO). Theoretical analyses, XRD, and SEM-EDS results demonstrate that H2 has a higher reduction ability than CO on oxidized VTM while CO makes a better role in promoting the grown of metallic iron particles, which are both crucial for Fe-Ti separation.