Beneficiation of a low grade Manganese ore from Balaghat, Madhya Pradesh, for Bhilai Steel Project

Abstract

A low grade manganese ore from Netra Mines Balaghat district, Madhya Pradesh assaying 29.24% Mn, 31.26% SiO2, 2.60% Al2O3, 7.77% Fe, 4.30% CaO, 2.89% MgO, 0.26% P, 0.35% S and 1.92% BaO, was received from the Indian Bureau of Mines at the instance of the Russian experts now in India in connection with the erection of a steel plant at Bhilai. Braunite was the predominant manganese minerals and quartz and manganese amphiboles and pyroxenes formed the principal gangue constituents. Hematite, jacobsite, hausmanite, and their intergrowth (vredenburgite), calcite, garnet, mica, barytes and feldspar were present in small amounts. Though an appreciable amount of quartz and other light gangue could be eliminated by gravity methods at -1/2 , the manganese minerals were intimately associated with for production of a high-grade concentrate. Heavy media separation of the -2”+6 mesh fraction of the ore and jigging of the -6 mesh, followed by magnetic separation of the jig middling produced a concentrate assaying about 40% Mn with a recovery of about 90%. Jigging the -3+20 mesh fraction and tabling of the -20 mesh, followed by magnetic separation of the table middling yielded a combined concentrate assaying 42.04% Mn with a recovery of 75.3% Mn. Straight tabling of the -48 mesh ore after hydraulic classification, followed by magnetic separation of the table middlings produced a concentrate assaying 47.71% Mn with 61.8% manganese recovery.