A novel method to extract V3+ from iron vanadate spinel minerals by one leaching step

To alleviate the energy consumption and the effluent of traditional oxidizing roasting and leaching process of vanadium extraction, a novel method to extract the vanadium from iron vanadate spinel mineral (Fe3-xVxO4) by one leaching step was developed. In this method, the Fe powder was found as a synergist of oxalic acid to leach the vanadium as [V(C2O4)(3)](3-) complex under hydrothermal condition. With the synergy of Fe powder, the leaching efficiency of V3+ ions from iron vanadate spinel concentrate was enhanced significantly, and simultaneously Fe3+ ions present as impurity in the pregnant leachate were eliminated effectively by forming FeC2O4 center dot 2H(2)O precipitate. Using the most suitable conditions, the leaching efficiency of vanadium can reach 95%, reducing Fe3+ to less than 100 mg/L. Furthermore, FeC2H2O4 center dot 2H(2)O with 98% purity could be obtained as a byproduct by washing the filtered cake.