Effect of calcination conditions on the physical properties of sorbents used for sulfur dioxide removal

The effect of calcination conditions on the physical properties of calcines produced from natural Turkish limestones and dolomites was investigated. Calcination experiments were conducted in a tube furnace at temperatures of 1073, 1123, 1173, 1273, and 1373 K. Two different gaseous atmospheres were employed, namely, dry air (100 vol%) and a mixture consisting of CO2 (15 vol%) and dry air (85 vol%). The physical properties, which involve bulk density (g/cm3), total pore volume (cm3/g), and the pore size distribution of the calcines prepared under different conditions, were determined using a mercury porosimeter. It was found that the physical properties of calcines were dramatically affected by the calcination conditions. At high calcination temperatures, because of sintering and shrinking effects, a decrease in porosity, an increase in bulk density and average pore radius were observed. In addition, the calcines prepared in a mixed atmosphere of dry air and carbon dioxide had larger pore size than those of calcines prepared in an atmosphere of dry air.