Abstract:Applying nickel-cobalt leachate of cobalt-rich crusts through SO2 reduction and acid leaching process as raw material, the experimental research on iron removal, sulfide precipitation, preparation of manganese sulfate, manganese sulfate roasting and decomposition, and sulfur recycling were carried out to realize impurity removal and purification of leachate, and recycling of sulfur. The optimal process parameters were obtained and the possibility of manganese decomposition recovery and sulfur recycling was carried out. The results show that: 1)Iron removal process: when pH value is 3.5, reaction time is 360 min, and with oxygen supply, iron removal rate is 99% above; 2)Sulfidation precipitation process: NaHS is used as precipitant with S/Co=3, precipitation rate of Ni and Co is more than 98%; 3)Preparation of manganese sulfate: evaporation temperature is 120 ℃, stirring rate is 350 r/min, and reaction time is 3 h, the main composition of crystal is MnSO4·H2O with Mn content of 27.95% ;4) Sulfur recycling process: when amount of anthracite is 7%, roasting temperature is 800 ℃, and roasting time is 15—30 min, the decomposition rate of manganese sulfate obtained by evaporation of solution after sulfide precipitation is 96.72%, the decomposition product is Mn3O4. The gas generated during roasting process is directly used to leach cobalt-rich crusts, the leaching rate of Ni, Co, Cu, and Mn is all 95% above, and sulfur recycling is realized.