Thermodynamic analysis on the direct preparation of metallic vanadium from NaVO3 by molten salt electrolysis

A novel and environmentally friendly route to directly prepare metallic vanadium from NaVO3 by molten salt electrolysis is proposed. The feasibility about the direct electro-reduction of NaVO3 to metallic vanadium is analyzed based on the thermodynamic calculations and experimental verifications. The theoretical decomposition voltage of NaVO3 to metallic vanadium is only 0.47 V at 800 °C and much lower than that of the alkali and alkali earth metal chloride salts. The value is slightly higher than that of low-valence vanadium oxides such as V2O3, V3O5 and VO. However, the low-valence vanadium oxides can be further electro-reduced to metallic vanadium thermodynamically. The thermodynamic analysis is verified by the experimental results. The direct preparation of metallic vanadium from NaVO3 by molten salt electrolysis is feasible.