MNO2 is used as catalyst in contact filter for rapid oxidation of dissolved iron and manganese, which are present in the form of ferrous and manganous salt. Dissolved Oxygen oxidizes these salts to insoluble ferric and manganic salt. PH of incoming water has to be corrected to around 9 for ferrous salts and 9 to 10.5 formanganoussalts. Air is injected into inlet water to provide sufficient dissolved Oxygen for oxidation.
- Catalyst for oxidation of dissolved ferrous & manganous salts.
- Drying agent for paints and varnishes.
- Manufacture of dry batteries.
- For imparting brown glaze to earthenware and tiles.