Leaching of Manganese by Sulfuric Acid From Low-grade Pyrolusite Using Lead Sulfide Concentrate as Reductant

Leaching of low-grade pyrolusite using sulfuric acid as leaching agent,lead sulfide concentrate as reducing agent and scrap iron as addition agent was studied.The influences of ingredients ratio,leaching temperature,sulfuric acid concentration,reaction time,liquid-solid ratio on manganese leaching were examined.The results show that the manganese leaching rate can reach96.17% and almost all lead into the leaching slag under the appropriate conditions.The formation of elemental sulfur and leaching temperature have significant influence on manganese leaching.The affecting formation of elemental sulfur is concentration of sulfuric acid(slurry pH).Optimal leaching conditions are m(pyrolusite)∶m(galena)∶m(iron)of 3∶1∶1,reaction time of 2hours,sulfuric acid concentration of 2mol/L,leaching temperature of 90 ℃,liquid-solid ratio of 5∶1,ore particle size of-74μm accounting for 90%.