Precipitation of vanadium using ammonium salt in alkaline and acidic media and the effect of sodium and phosphorus

Two kinds of precipitation processes: ammonium salt precipitation of vanadium in alkaline media and ammonium salt precipitation of vanadium in acidic media from the stripping solution of N235-P507 synergistic extraction system were investigated. Both of them were found to be feasible for the high-efficient and selective extraction of vanadium from vanadium-bearing shale combined with N235-P507 synergistic extraction system. During the ammonium salt precipitation of vanadium in alkaline media, the crystal of sodium vanadates formed in the vanadium precipitate and the purity of the V2O5 product was affected when Na was 23 g/L. The vanadium precipitate was washed by 2% NH4Cl solution after ammonium salt precipitation of vanadium in alkaline media and high quality product contained 98.431% V2O5 was obtained by the calcining of refined vanadium precipitate. During the ammonium salt precipitation of vanadium in acidic media, Na had no significant effect while P had a great impact on the precipitation rate and purity of V2O5 product. After P was removed by MgSO4, the precipitation rate of vanadium was more than 99% and purity of V2O5 product was 99.761% by the ammonium salt precipitation of vanadium in acidic media.