Beneficiation of Lime-sludge from Titagarh Paper Mills Ltd., Calcutta

Abstract

A Sample of lime sludge from Titagarh Paper Mills Co. Ltd., Calcutta, assaying 44.1% CaO, 2.8% MgO, 11.5% SiO22.5% Al2O3, 31.6% CO2 and 1.3% Na2O was received from M/s. Bird & Co (Pvt.) Ltd., Calcutta for beneficiation studies, so that the concentrate could be used as flux in steel industry or other places. Calcite was predominant minerals followed by minor amounts of dolomite. Free lime and soda were also present in the sample. The gangue consisted of quartz, diatomite, felspars and traces of muscovite, talc and coal. Flotation performed with the original sample as well as after grinding and removal of soluble alkalies did not give encouraging results. Due to the presence of firm coating of carbonates over most of the siliceous gangue the sample was not amenable to concentration by flotation.