Abstract:The effects of different sequences of reduction and neutralization of vanadium acid leaching solution of stone coal on vanadium loss and reduction degree, as well as the valence state changes of vanadium ion and iron ion were studied to provide methods and theoretical guidance for the preparation of qualified vanadium extraction solution. The results show that compared with the first reduction and then neutralization process of vanadium acid-leaching solution of stone coal, the vanadium loss rate of the first neutralization and then reduction process is small (<4%), and the amount of reducing agent Na2S2O3 is the same, so the first neutralization and then reduction process was chosen. First, neutralize with calcium carbonate and control the neutralization endpoint pH value from 2.2 to 2.3, then reduced by Na2S2O3 with the amount of 15.0—20.0 g for one liter acid leaching solution, and the pH value of the solution after neutralization and reduction is from 2.9 to 3.0. Thus, the best vanadium extract was prepared. By studying the valence changes of iron and vanadium during the neutralization and reduction process of vanadium acid leaching solution, it can be seen that the reduction degree of iron and vanadium and the loss degree of vanadium can be judged regardless of the sequence of neutralization and reduction of vanadium acid leaching solution. The optimal dosage of one liter Na2S2O3 is 15—20 g, which can be used as an auxiliary means to study the neutralization and reduction process of vanadium acid leaching.