Acid leaching kinetic study of vanadium from Saghand –e- Yazd magnetite ore

In the present research, the vanadium recovery mechanisms from Saghand –e- Yazd magnetite ore by sodium carbonate was studied as oxidant and acid leaching technology, and also the effect of the different parameters on the kinetics of the vanadium dissolution was investigated. The results showed that the temperature of roasting, the time of roasting  , sodium carbonate as the factor of roasting, as well as the temperature of leaching, time of leaching, size of ore particles, sulfuric acid concentration, and liquid to solid ratio are very important factors in the efficiency of vanadium extraction from ore. Optimum parameters in roasting process were considered temperature: 1000 °C, roasting  time: 2 h, sodium carbonate: 40 wt% (additive roasting), also leaching temperature: 85 °C, leaching time: 4 h, particle size: smaller than 100 microns the concentration of sulfuric acid: 4 M and liquid to the solid ratio: 10/1 mL/g were obtained in the leaching process. According to the kinetic study of the vanadium leaching based on SCM model, it was concluded that the control effect of the leaching process is intra-particle penetration. Therefore, the vanadium leaching process follows the 1-2/3X-(1-X)2.3</sup> kinetic model. Also, the activation energy of the process was 2.19 kcal per mole, which corresponds to the reported theoretical values for the state in which the intra-particle penetration controls the process.