Based on the principle of calcified roasting and E-pH diagram of acid leaching

the loss of vanadium and iron in calcified roasting and acid leaching were investigated with vanadium-bearing titanomagnetite as raw material and calcium sulfate as calcification agent. The vanadium extraction process combining calcified roasting and acid leaching was feasible in theory. The loss ratio of vanadium in pellets increased with increasing temperature in the calcified roasting process. Despite some loss of vanadium the calcified roasting process was favorable to the subsequent acid leaching of vanadium. The leaching ratio of vanadium increased with increasing roasting temperature below 1450 K. The leaching ratio reached a maximum at 1450 K

and then it decreased. The leaching ratio of vanadium had no obvious change with increasing sulfuric acid concentration. At the same time

the loss ratio of iron in the leaching process increased rapidly when roasting temperature was higher than 1450 K

and it also increased with increasing concentration of sulfuric acid. By controlling experimental conditions

the leaching ratio of vanadium in vanadium-bearing titanomagnetite could reach 79.08% but the loss ratio of iron was 3.32%.