A Novel Technology to Prepare FeVO4 from TiCl4 Refining Tailings.

In this work, vanadium is extracted from TiCl₄ refining tailings by a clean metallurgical process and FeVO₄ is prepared by adjusting the pH of acid leaching solution. The main factors affecting the leaching of vanadium from tailings are leaching temperature, solid-to-liquid ratio, hydrochloric acid concentration and type of oxidant. Under the optimal leaching conditions, when the leaching temperature is 30°C, the solid-liquid ratio is 1 : 4, the hydrochloric acid concentration is 400 g/L, and the oxidant is H₂O₂, the leaching rate of V can reach 97.1% after 60 min of reaction. The main factors affecting the precipitation of FeVO₄ are the precipitation temperature, the initial vanadium concentration, the pH endpoint value of acid leaching solution and the addition amount of H₂O₂ oxidant. Under the optimal precipitation conditions, when the precipitation temperature is 40°C, the initial vanadium concentration is 5 g/L, the pH endpoint value of the acid leaching solution is 1.4, the addition amount of H₂O₂ oxidant is 6%, the precipitation rate of V can reach 95.4% after 60 min. By adjusting the pH value of precipitation filtrate, metal ions such as Fe, Al, Ca and Mg precipitate to form neutralization slag. The neutralization filtrate can be prepared NaCl crystals by evaporation crystallization, and the mother liquor of evaporation crystallization is returned to acid leaching for use. Acid leaching residue (TiO₂ content is 55.42%) can be recycled as high-titanium raw material. This study can properly deal with the environmental pollution caused by the stacking of TiCl₄ refining tailings. [ABSTRACT FROM AUTHOR]