Dissolution behavior and mechanism of low valence vanadium of vanadium-iron spinel in sulfuric acid solution

Compared with the traditional method of extracting V(V), extracting low valence vanadium (LVV) directly from vanadium containing raw material can shorten the extracting process and prevent the generation of poisonous residual and waste water bearing V(V). Vanadium-iron spinel is the main vanadium containing component in vanadium slag and in which the vanadium is in trivalence state. In this work, the dissolution behavior of LVV from vanadium-iron spinel Fe2VO4 in sulfuric acid solution was investigated systematically, and the dissolution mechanism was discussed accordingly. The results indicated that a maximum LVV recovery from Fe2VO4 was as high as 96.54% without the generation of V(V), which showed the possibility of extraction LVV. Besides, the dissolution temperature was the most important factor affecting the recovery of LVV. The surface chemical reaction was rate-determining step and the apparent activation energy was 43.02 kJ/mol. After dissolution, the vanadium existed in the form of VO2+ in the solution. This study could provide guidance for extraction of LVV directly from vanadium bearing raw material.