A green and sustainable method for stepwise extraction of V and Ti from vanadium slag using super-gravity

At present, the utilization of vanadium slag suffers from underutilization of Ti resources and the generation of large quantities of toxic tailings. Therefore, there is an urgent need for a green and sustainable process to achieve the recovery of V and Ti from vanadium slag. In this study, the crystallization mechanism of V and Ti in vanadium slag with basicity and temperature was revealed. The results indicated that V in vanadium slag with a basicity of 1.6 was enriched primarily to Fe₂VO₄ at 1500-1400 °C, whereas Ti was mainly crystallized into CaTiO₃ at 1400-1200 °C. On this basis, above 90.22 % of V and 87.89 % of Ti were firstly recovered into Fe₂VO₄ and Ti-enriched slag via super-gravity at 1400 °C, respectively. After that, over 81.04 % of Ti was further recovered into CaTiO₃ from the Ti-enriched slag via super-gravity at 1200 °C. Following two separations, the high-purity Fe₂VO₄ with up to 40.56 wt% V₂O₃ and CaTiO₃ with up to 54.42 wt% TiO₂ were obtained, which could be used for the preparation of FeV alloy and Ti pigments. The tailings with a FeO content exceeding 39.93 wt% could be further used to recover Fe. This method simultaneously extracts V and Ti resources from vanadium slag, avoids the generation of toxic tailings at source, and can combine with the current V metallurgy process, realizing the comprehensive utilization of vanadium slag in a green and sustainable way.