Beneficiation of low grade Manganese ore from Chitaldrug, Mysore

A low grade ferruginous manganese ore from Chitaldrug, Mysore, assayed Mn, 32.51; Fe, 20.59; manganese minerals were psilomelane, pyrolusite, hollandite and braunite and goethite, were very intimately interlocked with manganese minerals, requiring grinding to about 250 mesh for fair liberation. Reduction roast of unwashed ore at-3 mesh followed by magnetic separation at -48mesh gave a manganese concentrate assaying 53.69% Mn (Mn/Fe ratio 7:1) with a recovery of only 48.3% Mn. Heavy loss of manganese in the iron concentrate resulted in poor manganese recovery in the concentrate. The grade of concentrate a Mn/Fe ratio of 7:1, improved to 54.4% manganese for a recovery of 52% when washed ore was used for reduction roast and magnetic separation of the reduced ore performed at -48 mesh. Magnetic separation at finer size did not improve the results.