Beneficiation of low grade Manganese ore from Lohandabud Group of Mines, Jharsuguda, Orissa

Three samples of low grade manganese ore (marked La, Lc & Ld) were received from M/s. Shivji Nathubhai of Jharsuguda, Orissa, for beneficiation studies. The mixed sample assayed Mn, 40.02 % ; MnO2, 34.71% Fe, 4.82% SiO2, 19.34% , Al2O3, 3.8% CaO, 1.1%; BaO, 3.32% MgO, 0.69 % and P, 0.18%. Braunite was the principal manganese mineral followed by psilomelane, hausmanite, pyrolusite, jacobsite, hollandite, sitaparite and vredenburgite while quartz, garnet and pyroxenes constituted the chief gangue followed by amphiboles, barytes, biotite, feldspars and hematite. Electrostatic separation of the magnetic product , obtained from high intensity magnetic separation after hydro-classification of the -35 mesh ground mixed sample, gave a concentrate assaying 45.2% Mn and 9.7% SiO2 with a recovery of 63.4% Mn. Cationic flotation using Armeen -12D as collector for siliceous gangue at a pH range of 8-8.5 produced manganese concentrate assaying 44.8% Mn and 11.0% SiO2 with recovery of 60.0% Mn. Due to very complex nature of the mixed sample, its beneficiation to the desired extent could not be achieved. However, the sample Ld alone, when subjected to high intensity magnetic separation yielded a concentrate assaying 46.2% Mn and 7.7% SiO2 with a recovery of 85.8% Mn indicating alone, without mixing with the other samples.