Abstract:Mn was leached with oxidation of manganese dioxide and sulfuric acid, and most of iron was removed in pH=4.0, then Ca and Fe were removed with P204, finally, high purity manganese sulfate was prepared by concentration and crystallization. Manganese leaching rate is 93.5% under the optimum conditions including concentration of sulfuric acid of 100 g/L, L/S of 6 mL/g, mass ratio of manganese slag to 70%MnO2 of 8, leaching temperature of 90 ℃, and leaching time of 180 min. 84.8% of iron is removed from lixivium by adjusting pH=4.0, concentrated to 20 mL and adjusted to pH=1.6, extraction rate of calcium and iron is 91.2% and 80.5% respectively by extractant of P204 and sulfonated kerosene (volume ratio of 1︰1, saponification rate of 30%) and extraction time of 10 min. Regulate pH value to 3.5, extraction rate of manganese is 92.9% by P204 and sulfonated kerosene (volume ratio of 2︰1, saponification rate of 30%) and extraction time of 10 min. Finally, high-purity manganese sulfate is prepared by concentrating and crystallizing. Total recovery of manganese is 82.6%, purity of manganese sulfate is 99.78% with iron content of 0.0012% and calcium content of 0.0023%.Key words: Manganese slag; leach; P204;manganese sulfate