A novel process for recovery of iron, titanium, and vanadium from titanomagnetite concentrates: NaOH molten salt roasting and water leaching processes

[Display omitted] ► The conversion of titanium is 96.6% in the rich titanium–vanadium slag. ► MgTi2O5 and M3O5 (M=Ti, Mg, Fe) were converted to Na2TiO3 and NaMO2, respectively. ► Na2TiO3 is converted to undefined structure of H2TiO3. ► NaMO2 is converted to α-NaFeO2-type structure of HMO2. ► 87.3% of sodium, 42.3% of silicon, 43.2% of aluminum, 22.8% of manganese and 96.6% of vanadium were leached out. A novel process for recovering iron, titanium, and vanadium from titanomagnetite concentrates has been developed. In the present paper, the treatment of rich titanium–vanadium slag by NaOH molten salt roasting and water leaching processes is investigated. In the NaOH molten salt roasting process, the metallic iron is oxidized into ferriferous oxide, MgTi2O5 is converted to NaCl-type structure of Na2TiO3, and M3O5 (M=Ti, Mg, Fe) is converted to α-NaFeO2-type structure of NaMO2, respectively. Roasting temperature and NaOH–slag mass ratio played a considerable role in the conversion of titanium in the rich titanium–vanadium slag during the NaOH molten salt roasting process. Roasting at 500°C for 60min and a 1:1 NaOH–slag mass ratio produces 96.3% titanium conversion. In the water leaching process, the Na+ was exchanged with H+, Na2TiO3 is converted to undefined structure of H2TiO3, and NaMO2 is converted to α-NaFeO2-type structure of HMO2. Under the optimal conditions, 87.3% of the sodium, 42.3% of the silicon, 43.2% of the aluminum, 22.8% of the manganese, and 96.6% of the vanadium are leached out.