Reduction of Silica content of Limestone samples from Sirka, after Calcination

With the main object of lower in, the silica content of calcined lime by ore dressing methods, two samples of siliceous low grade limestone analyzing 34.95% CaO, 24.30% SiO2, and 35.3% CaO, 21.8 SiO2 respectively were received from Messrs, Bir & Co. The samples after calcinations assayed 50% CaO, 34.7 SiO2 and 52.0 CaO, 31.0 SiO2 respectively. Froth flotation did not yield satisfactory results. On the other hand, hydro-classification after slaking of the calcined limestone could yield concentrates assaying 64.48% CaO, 3.31% SiO2, and 60.5% CaO, 6.0% SiO2 with lime recoveries of 64.7% and 66.1 respectively. These concentrates may be considered suitable for use in building construction.