摘要
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.
The direct sulfation of limestone from different sources in Iran was studied in a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higher than 97% CaCO3, Experimental conditions were as follows: particle size levels ranging from 1.6μm to 7.8 μm, four level reaction temperatures (700℃, 750℃, 800℃ and 850℃), and two SO2 concentrations (2.4×10^-3 and 3.2×10^-3 mol.mol-1). The particle size and temperature showed dominant influences on the rate and level of conversion while the effect of SO2 concentration was weak. The shrinking core model can be used to describe the behavior of the sulfation process. The reaction kinetics and diffusion mechanism are both important in controlling the rate of the process. The two key parameters of the model, chemical rate constant Ks and effective diffusion coefficient Deft were obtained. Model predictions are in good agreement with the experimental data.
