THERMOGRAVIMETRIC ANALYSIS ON CHARACTERISTICS OF LIMESTONE CALCINATION AND DESULPHURIZATION

The experiments of limestone calcination and sulphation have been carried out in TGA. The effect of particles diameter, heating rate and furnace temperature on calcination have been studied. The decomposition of limestone in air follows the function f(α)=l-α. The effect of limestone's type, particle diameter, furnace temperature and gas content of S0₂and 0₂ on sulphation have been studied. From the results of the experiments, the initial sulphation is controlled by the film diffusion and the chemical reaction and the later sulphation is controlled by the product layer diffusion which is affected by the pore diameter and porosity of limestone. A kind of man-made desulphurizer has been made and studied in TGA. The calcium utilization ratio reaches 68.1% and the optimum temperature of sulphation can be raised to 950°C