Abstract: Manganese sulfate was produced from low-grade pyrolusite in sulfuric acid meduim using bagasse as the reducing agent.Influences of the particle sizes of pyrolusite and bagasse，stirring speed，mass ratio of bagasse to pyrolusite，sulfuric acid concentration，reaction temperature，ratio of liquid to solid，and reaction time on the leaching rate of manganese were investigated.By using single-factor experiments，the optimal conditions were obtained as follows：the mass ratio of bagasse to pyrolusite was 4∶1，the initial mass fraction of sulfuric acid was 30%，the reaction temperature was 35 ℃，the stirring speed was 650 r/min，the ratio of liquid to solid was 40∶1，the particle sizes of pyrolusite and bagasse were both at 109~120 μm，and the reaction time was 6 h.Under these process conditions，the leaching rate of manganese could reach more than 97%.

Key words: pyrolusite, manganese sulfate, bagasse, leaching rate