为了了解喷钙过程中硫元素赋存形态,研究了820~1400℃下CaS的氧化反应机理.采用热重实验研究了CaS质量变化特性,利用红外光谱仪定量分析反应析出气体.研究表明,在820~970℃,CaS氧化反应呈增重趋势;在1000-1150℃,反应呈先失重后增重趋势;在1200~1400℃,反应呈先失重后增重再失重的趋势.随温度升高,SO2析出速率及析出量也增大.在890℃以下,以SO2形式析出硫分不到全硫分的2%,CaS与CaSO4的固-固反应基本可以忽略.而在930℃~1150℃内,CaS与CaSO4的固-固反应加剧,SO2析出量占全硫分的10.16%~67.90%.当温度高于1175℃,CaSO4的高温分解也造成SO2的析出。
In order to deal with the distribution of sulfur element during calcium sorbent injection, the oxi- dation mechanism of CaS at 820-1400℃ was studied. After characteristic of mass change during CaS oxidation was investigated by means of thermogravimetric analysis,the exhausted gas was quantitatively analyzed by infrared spectral method. Results show that reactions are characterized by a mass gain at 820-970℃, and by a mass gain after mass loss at 1 000-1 150 ℃ Samples lose weight first, followed by a rapid mass gain and finally decrease at 1 200-1 400 ℃. The release rate and the amount of SO2 decrease with the increasing temperature. Sulfur lower than 2% is released as SO2 below 890℃ and the reaction between CaS and CaSO4 can be ignored . Sulfur at 10. 16-61.90% is released as SO2 at 930-1 150℃. Part of SO2 released is attributed to the decomposition of CaSO4 above 1 175℃.