Abstract:Applying manganese ore imported from Africa as raw material and coke as reductant to prepare manganese sulfate solution by reductive roasting and sulfuric acid leaching. The effects of coke ratio, roasting temperature and roasting time on reduction effect of manganese were investigated, and the optimum process parameters were determined. Thermodynamic analysis of roasting reaction system and kinetic analysis of the leaching process were carried out. The results show that reduction rate of manganese is 97.84% under the optimum roasting conditions including coke ratio of 15% and roasting time of 60 min at 800 ℃. The reaction of roasting system is spontaneous, and the leaching process is controlled by internal diffusion with apparent activation energy of 22.4586 kJ/mol, and the kinetic equation is as follows: 1—2x/3—(1—x)2/3=8.48exp(-22458.6/RT)×t.