Preparation technology of high purity vanadium pentoxide

Ammonium polyvanadate produced by traditional methods is used as raw material. According to the different solubility of each element in the raw material, ammonium polyvanadate is redissolved with ammonia water, and impurity removal is carried out in the low solubility area to prepare high purity V₂O₅. The influence of remelting temperature and pH value on the solubility of each element in the raw material and the composition of the solution is studied. The results show that with the increase of temperature and pH value, the resolubility of V is favorable. The solubility of Si, Fe, Cr and P changes little, and the solubility value is small, and these impurities can be removed by re-solution filtration; Impurity elements K, Na, S have high solubility and change greatly, and their low solubility region can be selected for filtration. Between 30 ℃ and 90 ℃, the contents of impurity elements K, Na and S decrease first, then increase, and finally decrease, so the high temperature zone of the impurity element reduction section 85 ℃ is selected for re-dissolution. The pH value is between 6 and 10, and the content of K, Na, and S elements in the solution increases first and then decreases with the increase of pH value, so the impurity reduction area with a high pH value of 9 is selected for impurity removal. When the resolution temperature is 85 ℃ and pH is 9, ammonium metavanadate obtained by filtration and hydrolysis of vanadium or ammonium polyvanadate obtained by filtration and hydrolysis of vanadium can be obtained after calcination, and the purity of high purity V₂O₅ can reach more than 99.9%.