Beneficiation of Limestone from Govt. Cement Factory, Churk, U.P.

A sample of limestone received for beneficiation from Govt. Cement Factory, Churk, U.P. assayed 42.7% CaO, 35.5% CO2, 0.12% SO3, 3.01% MgO, 14.1% SiO2, 3.25% Al2O3 and 1.01% Fe2O3. Shale was the chief gangue with minor amounts of quartz and limestone was fairly liberated from the gangue at about 100 mesh. Optimum conditions for flotation of limestone were determined for production of a concentrate suitable for the manufacture of cement. Flotation employing 1.25lbs/ton of oleic acid and 1.5 lbs/ton of sodium silicate produced a concentrate assaying 45.36% CaO with a recovery of 98.4% CaO. Reflotation of this concentrate improved the grade to 47.90% CaO with a recovery of 93.1% CaO. This product which satisfies the specifications can be employed for the manufacture of cement.