Reduction of Silica content in a Magnesite sample from Salem, Madras State

A magnesite sample from Salem from , Madras State assaying 45.31% MgO, 1.46% CaO, 48.5% CO2, 3.91% SiO2, 0.3% Al2O3,0.55% Fe2O3 and 0.12% S was received from M/s. Dalmia Magnesite Corporation for reducing its silica content. Quartz, serpentine, felspar, ferromagnesium minerals and opaques were the principal gangue in the sample. Flotation using fatty acid as the collector produced a magnesite concentrate assaying 1.4% SiO2 and 0.26% CaO with a yield of 73.4% by weight recovery of about 0.9% SiO2 could be obtained after three cleanings.