Beneficiation of low grade Manganese ore from K-B Mines, Shimoga District, Mysore

A low grade manganese ore from K-B Mines, Shimoga and P, 0.071 percent was received from M/s. S.Lal & Co., for mineral followed by psilomelane and braunite. Quartz was the chief gangue followed by goethite, ochre and pyroxenes. Liberation of quartz occurred at about 250 mesh size. Straight flotation tests using both anionic and cationic reagents did not yield a concentrate low both in iron and silica. Straight magnetic separation of the deslimed sample at -48 mesh after heat treatment followed by cationic flotation of slime yielded a combined manganese concentrate assaying Mn, 49.0; Fe, 7.3; SiO2, 10.4 with a recovery of 85.2% Mn. Reduction roast and magnetic separation followed by cationic flotation of non-magnetic product yielded a manganese concentrate assaying Mn, 56.4; Fe, 7.8; SiO2, 9.8 percent with a recovery of 79.2% Mn.