Manganese Processing

The most important manganese ores are the oxides pyrolusite, romanechite, manganite, and hausmannite and the carbonate ore rhodochrosite. Rhodonite and braunite, both silicate ores, are frequently found with the oxides. Only ores containing greater than 35 percent manganese are considered commercially exploitable. Impurities include oxides of other metals, such as iron, that are reduced along with manganese upon smelting, non-metallic elements such as phosphorus, sulfur, and arsenic, and metallic, gangue oxides, such as silica, alumina, lime, and magnesia, which, with the exception of silica, generally remain in the slag.