Beneficiation of low grade Manganese ore from Kamji Mine Talwara, Banswara, Rajasthan

Abstract

A low grade manganese ore from Kamji mine, in Talwara, Banswara, Rajasthan assayed 21.74% Mn 14.23%Fe, 18.22% CaO, 3.46% SiO2, 0.58% P and 1.89% Al2O3. The manganese minerals viz. Psilomelane and Pyrolusite were in very intimate association with Calcite. Hydrous iron oxides, quartz and apatite were the other gangue minerals. Straight tabling or straight magnetic separation did not produce satisfactory grade of manganese concentrates. Reduction roast of the -3 mesh unwashed original sample followed by magnetic separation at -20 mesh yielded manganese concentrates assaying between 34.7% to 35.68% Mn with recoveries varying from 57.6% to 66.4% Mn and with Mn:Fe ratio varying between 6.5:1to 7.5:1. The sample even after beneficiation remained a low grade ore high in CaO and P contents. The ore could be blended with other ores of the locality which are highly siliceous low in P, and then beneficiated, perhaps by electrostatic separation, as indicated by a study of a more representative sample from the locality.