Method for industrially obtaining metallic manganese or pure manganese dioxide

摘要

In the production of manganese or manganese dioxide by the electrolysis of manganese sulphate solution, the latter solution, free from iron, is obtained by roasting manganese ore at 750 DEG C. or above and then treating the roasted ore still at the high temperature with sulphuric acid to dissolve the Mn3O4, the insoluble MnO2 formed during the dissolution being subjected to further roasting and acid treatment until the insoluble material is substantially exhausted. Acid formed during electrolysis is recycled to the acid treating operation.