Acid leaching of Turkish celestite concentrate

The grade of final celestite concentrate is as high as 95–96% after jigging and table washing operations applied by Barit Maden Turk in Turkey. Celestite concentrate contains 95% SrSO4, and 3% CaSO4, 0.5%BaSO4, 0.5% SiO2, 0.5%Fe2O3 as major impurities. Before the conversion of celestite to strontium carbonate with the double decomposition method, the iron content of celestite must be decreased to below 0.10 g/L. This study concerns the acid leaching of Turkish celestite concentrate. A purity of celestite of 98% could be obtained using 50% H2SO4 and 1–3% HNO3 at 40–50 °C and the content of the impurities is about 0.005% Fe, 0.11% Ca, 0.6% Ba, 0.086% Pb and 0.2% others. Strontium carbonate produced from cleaned celestite ore by the method of double decomposition contained iron below 0.10 g/L and calcium below 0.2%.