二氧化硫对石灰石的直接硫酸盐化作用的热重分析的研究与建模

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 7.8μm, four level reaction temperatures (700°C,750°C, 800°C and 850°C), and two SO2 concentrations (2.4 × 10-3 and 3.2 × 10-3 mol.mol-i). 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 Deff were obtained. Model predictions are in good agreement with the experimental data.

Thermogravimetric Study and Modeling of Direct Sulfation of Limestone by Sulfur Dioxide