Review and perspective of vanadium extraction techniques from converter vanadium-bearing slag

It is an important aspect to ensure the sustainable development of China's vanadium industry by efficiently low-cost and green recover the vanadium from converter vanadium-bearing slag. Based on the composition and phase characteristics of the vanadium-bearing slag, the existing vanadium extracting techniques employed by different companies in the world were comprehensively summarized. The principle, advantages, as well as existing problems related to different vanadium extracting processes were clarified in reference to the traditional processes, i.e., sodium roasting - water leaching, calcification roasting-acid leaching, cleaner production technology of vanadium oxide by Panzhihua Iron and Steel Co. Ltd., and novel processes including microwave roasting, super-gravity selective separation, microbial metallurgy, etc. With the advancement of global carbon neutral targets, the development of future novel vanadium extracting technique should pay more attention to solve the existing environmental and resource problems including the large production of saline wastewater, the difficult harmless of the ammonium mirabilite and the difficult in re-using the sodium from the vanadium tailings. Meanwhile, the construction of the thermodynamic database and the dynamic models for the micro migration mechanisms of valuable metals should also be studied more deeply, and the advantages of microwave, super gravity, ultrasonic, etc. should be applied in traditional techniques. Furthermore, other valuable metals presented in vanadium-bearing slag should be efficiently recovered to realize pollution source abatement. Based on the new techniques and fundamental data, the further vanadium extracting process should be developed in the direction of green, low cost, short flow route and high efficiency. © 2021, Chemical Industry Press Co., Ltd. All right reserved.