Experiments and model of the decomposition of CaSO4 under CO atmosphere
CaSO4在CO气氛下的平行竞争反应实验与模型研究

The decompositon of CaSO_4 is the key reason for the low efficiency of the desulphurization in grate furnace. In this paper , the decompostion of CaSO_4 was investigated by means of a Metteler Toledo TGA with a infrared spectral analyzer for exhausted gas under isothermal condition. The mass fraction of CaS in final solid product was analyzed with the spectrophotometric measurement using ethylene blue. CaSO_4 is converted to CaO and CaS simultaneously by parallel reactions under CO atmosphere. Under 0.5%CO atmosphere, CaSO_4 is mainly converted to CaO. However, under 4%CO atmosphere CaSO_4 is mainly converted to CaO in initial stage and CaS in latter stage. The mass fraction of CaS in final solid product increases with increasing the concentration of CO and decreases with increasing the temperature. The model of parrallel reactions could depict the decompositon of CaSO_4 well under CO atmosphere.