Anodic Extraction of Vanadium from Crude Vanadium Produced by Carbothermic Reduction

Abstract

The anodic extraction of vanadium from crude vanadium (93.4–97.3 wt%) produced by carbothermic reduction was studied in the temperature range of 700–850°C, in the cell voltage range of 0.2–1.0 V, and in the four kinds of electrolytes KCl–NaCl–VF3(47.5–47.5–5), KCl–NaCl–K2NaVF6 (47.5–47.5–5), KCl–NaCl–NaF–K2NaVF6(44–44–7–5), and KF–NaF–K2NaVF6(62–33–5). The highest anode current efficiency was obtained under the conditions of 0.8–1.0 V and 700–725°C in the KCl–NaCl–NaF–K2NaVF6 electrolyte. The anode current efficiency was found to be strongly dependent on the vanadium content of the crude vanadium. It was also found that the oxygen and carbon in the crude vanadium remain in the anode residue as VO, V2O3, VC, and free carbon.