Abstract:
Considering the differences of hydrochloric acid leaching fluorapatite, calcium molybdate and scheelite concentrate, the scheelite concentrates which contain high phosphorus and molybdenum were first treated by hydrochloric acid, under the conditions such as hydrochloric acid concentration 2.5 mol/L, reaction temperature 50 ℃, reaction time 2 h, liquid-solid ratio of 5:1. The results showed that over 99% of phosphorus was leached, molybdenum leaching rate was 44.76%, and the tungsten loss rate was only 1.84%. After that, based on the different solubility of tungstic acid and molybdic acid in hydrochloric acid, the scheelite concentrates were leached by hydrochloric acid. Under the conditions of hydrochloric acid concentration 4 mol/L, reaction temperature 80 ℃, reaction time 2 h and liquid-solid ratio of 5:1, the leaching rate of molybdenum reached 95%, and tungsten was leached in the form of tungstate in solid phase. Hence the loss rate of tungsten was only 1.55%, which realized the deep separation of molybdenum and tungsten.