The widely applied methods to extract vanadium are sodium roasting and calcified roasting. However, these roasting methods have difficulties in recycling of wastewater and efficient utilization of leaching residue, which contains high concentration of sodium or calcium sulfate, due to the variety of roasting additives radically. Therefore, a novelty extraction medium by roasting with MgO and leaching with sulfuric acid was introduced in this study. The oxidation and roasting mechanism were systematically studied, providing a theoretical basis for industrial extraction of vanadium. The result shows that under the optimum conditions, the roasting temperature of 900 °C, the Mg/V molar ratio of 0.6, and the roasting time of 1.5 h, the leaching efficiency of vanadium is above 90%. In the processes, vanadium spinel is converted into Mg_2V_2O_7 and Mn_2V_2O_7.
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