Vanadium extraction from titano-magnetite by hydrofluoric acid

Vanadium extraction from titano-magnetite by using hydrofluoric acid was put forward. The process of low intensity magnetic separation, hydrofluoric acid leaching, co-precipitation with NaOH, roasting with Na2CO3, circulating water leaching and precipitation of vanadium has been investigated. The results show that over 85% vanadium could be directly leached under the condition of sulfuric acid concentration of 5 mol/L, CaF2 dosage of 5%, leaching temperature of 95 °C, leaching time of 3 h and liquid to solid ratio of 3 mL/g. With the pH value of 4.5, temperature of 40 °C and time of 30 min, the co-precipitation rate of vanadium in the acid leaching solution was over 99%. The water leaching rate of vanadium of the co-precipitation reached 95% under the condition of roasting temperature of 800 °C, Na2CO3 dosage of 6%, roasting time of 1 h, leaching temperature of 90 °C, leaching time of 40 min, liquid to solid ratio of 2 mL/g and leaching stage of 4. Finally, the total recovery of vanadium could reach 81% and the purity of the product V2O5 was 99.65% meeting the standard specification with precipitation of vanadium and calcination.