The direct sulfation of limestone from different sources in Iran was studiedin a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higherthan 97% CaCO_3. Experimental conditions ...The direct sulfation of limestone from different sources in Iran was studiedin a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higherthan 97% CaCO_3. Experimental conditions were as follows: particle size levels ranging from 1.6 μmto 7.8 μm, four level reaction temperatures (700℃, 750℃, 800℃ and 850℃), and two SO_2concentrations (2.4 x 10^(-3) and 3.2 x 10^(-3) mol · mol^(-1)). The particle size and temperatureshowed dominant influences on the rate and level of conversion while the effect of SO_2concentration was weak. The shrinking core model can be used to describe the behavior of thesulfation process. The reaction kinetics and diffusion mechanism are both important in controllingthe rate of the process. The two key parameters of the model, chemical rate constant K_s andeffective diffusion coefficient D_(eff) were obtained. Model predictions are in good agreement withthe experimental data.展开更多
文摘The direct sulfation of limestone from different sources in Iran was studiedin a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higherthan 97% CaCO_3. Experimental conditions were as follows: particle size levels ranging from 1.6 μmto 7.8 μm, four level reaction temperatures (700℃, 750℃, 800℃ and 850℃), and two SO_2concentrations (2.4 x 10^(-3) and 3.2 x 10^(-3) mol · mol^(-1)). The particle size and temperatureshowed dominant influences on the rate and level of conversion while the effect of SO_2concentration was weak. The shrinking core model can be used to describe the behavior of thesulfation process. The reaction kinetics and diffusion mechanism are both important in controllingthe rate of the process. The two key parameters of the model, chemical rate constant K_s andeffective diffusion coefficient D_(eff) were obtained. Model predictions are in good agreement withthe experimental data.
