Clean preparation of V2O3 by one-step molten salt electrochemical reduction of soluble NaVO3

Vanadium oxide s, such as V 2 O 5 and V 2 O 3 , are important metallurgy products and mainly used to prepare V-based alloys for steelmaking. At present, vanadium oxide s are mainly produced by complex sodium salt roasting process. Serious environmental pollution, such as emission of ammonia nitrogen wastewater and NH 3 , are restrictive problems. Here, a clean and sustainable method for V 2 O 3 preparation is proposed by one-step molten salt electrochemical reduction of soluble NaVO 3 , i.e. an indispensable intermediate in traditional V metallurgy. The pollution issues are well solved. The theoretical decomposition voltages of different vanadate to various low-valence vanadium oxides were calculated. NaVO 3 with a solubility of 14.7 wt% is the most suitable vanadate for the direct preparation of V 2 O 3 by molten salt electrolysis. The effects of cathode structure, NaVO 3 content, electrolysis temperature and voltage on current efficiency and electricity consumption were systematically studied. High-purity V 2 O 3 with uniform particle distribution is obtained and the lowest electricity consumption is only 2.86 kWhkg −1 . V 2 O 3 is mainly produced by one-step electrochemical reduction of soluble NaVO 3 through two-electron transfer process. The economic evaluation for ferrovanadium production is preliminarily carried out. Compared with the traditional process, the cost for ferrovanadium production is lower by the aluminothermic reduction of V 2 O 3 which is prepared by clean one-step electrolysis of soluble NaVO 3 .