Recovery Vanadium from Vanadium-Bearing Hazardous Residues

The extracted vanadium residues of vanadium titanomagnetite is one of the most hazardous residues that have a large annual output. In the paper, vanadium was leached by composed leaching reagent of sulphuric acid, hydrofluoric acid and potassium permanganate from the residues. The process parameters such as reagent concentration, ratio of liquid to solid, temperature, leaching time, which impact on the vanadium leaching percent, were investigated. The results show that HF can destroy the silicate phase which surrounds the vanadium-iron spinel. The addition of KMnO4 can enhance the oxidation transformation of insoluble vanadium (trivalence) to soluble vanadium (tetravalence) or vanadium (pentavalence), thus improve the vanadium leaching percent to 85%, under the reaction conditions: granule size of 0.15–0.25 mm, 125 g L−1 H2SO4, 30 g L−1 HF, 3 wt% KMnO4, liquid-to-solid ratio of 5 mL g−1, at 90 °C for 4 h.