Beneficiation of low grade Ferruginous Manganese ore from Chitaldrug, Mysore

A low grade ferruginous manganese ore from Chitaldrug, Mysore, received for beneficiation tests, assayed 35% Mn, 45.66% MnO2, 24.7% Fe, 1.67% SiO2, 1.4% Al2O3, 0.41% BaO and 0.105% P. Pyrolustie was the principal manganese minerals followed by psilomelane while Goethite and Lepidocrocite constituted the chief gangue minerals. Reduction roast at-3 at-10 mesh size yielded a manganese assaying 59% Mn with a recovery of 70.5 % Mn for a Mn/Fe ratio of 7. Magnetic separation at finer sizes (-48 and -100 mesh sizes) of the reduced ore did not improve the results to any appreciable extent. A two-stage wet magnetic separation, first at -100 mesh and then after grinding the magnetic fraction to -100 mesh improved the manganese recovery only by 3% for a Mn/Fe ratio of 7, which obviously indicted that there was no appreciable advantages in grinding the ore finer than -10 mesh for magnetic separation.