关键词: 碳酸锰矿, 浸出, 动力学, 除铁, 硫酸锰

Abstract: By using low grade manganese carbonate ores to react with sulfuric acid，high purity manganese sulfate was pepared after purifying the leaching solution.Under the conditions of liquid to solid ratio of 5∶1，sulfuric acid concentration of 0.86 mol/L，agitation rate of 300 r/min，and reaction time of 80 min，the kinetics of leaching manganese was investigated.Results showed，the leaching process mainly followed the internal diffusion-controlled shrinking core model，and the apparent activation energy（Ea） was calculated to be 9.83 kJ/mol.Then，the leaching solution，which was obained by extracting 91.4% from mangnese ores at 70 ℃，was subjected to purification treatment.Firstly，adding manganese dioxide with dosage of 1.5 times of the theoretical value to the lixivium at 80 ℃，and Fe2+ was oxidized to Fe3+.Then Fe3+ was removed through hydrolysis. At the pH of 5.0，the iron-removal efficiency was 96.38%，and the loss ratio of manganese in iron-removal was merely 4.98%. Sodium dimethyl dithio carbamate（S.D.D） was used to precipitate the heavy metals.Under the conditions of that the temperature was about 60 ℃，the pH was 5.4~6.0，and the dosage of S.D.D was 1.2 times of the theoretical value，the retained Ni2+ content in the purified solution could reach less than 1.5×10-6 and the efficiency of removing Ni2+ was 95.3%. Finally， evaporation-concentration-crystallization method was carried out under the conditions of middle-temperature，purity of manganese sulfate product could reach 98%.

Key words: manganese carbonate ores, leaching, kinetics, iron-removal, manganese sulfate