Chlorination and purification of vanadium pentoxide with anhydrous aluminum chloride

A novel chlorination process was investigated to prepare high-purity vanadium pentoxide (V2O5). Anhydrous aluminum chloride (AlCl3) instead of toxic and corrosive chlorine (Cl2) was used as the chlorination agent. The chlorination temperature was decreased as low as 160 °C-170 °C. By adding sodium chloride (NaCl) into the chlorination system, the reaction rate and purity of the intermediate product, vanadium oxytrichloride (VOCl3) were both remarkably improved. Additionally, hydrolysis conditions were also discussed. It was found that the precipitation rate reached 93.56% under the conditions of vanadium concentration of 13.4-68.8 (V2O5)g/L and the ammonium adding coefficient of 0.8-1.0. Based on the optimal conditions, V2O5 with a purity of 99.95 wt% at least was obtained, the content of Fe, Al, Si, K, Na, Zn, P and other impurities were effectively reduced. Compared with the preparation method currently used in the industrial process, the novel chlorination method proposed is an environmently-friendly process with the low cost, high selectivity, and simplified operation advantages. Therefore, the novel chlorination method exhibits a competitive potential in industrial application.