碱、氯、硫在水泥窑炉中的挥发特性分析

Volatilization Properties of Alkali,Chlorine and Sulfur in Cement Kilns

根据吉布斯自由能最小原理,计算了在500℃-1400℃范围内碱(K)、氯、硫的平衡组分和挥发率,并结合水泥窑炉的温度分布,对碱、氯、硫的循环富集特性进行了探讨。结果表明:氯的挥发性很强,在800℃以上几乎达到100%,挥发率急变的温度区域为650℃-800℃;硫和碱大约在1300℃左右全部挥发,氯促进硫和碱的挥发,在氯含量较低时,硫和碱挥发率在1000℃-1200℃之间变化较大,而在氯含量较高情况下,在650℃-800℃也是急剧变化。对应于水泥生产实际,循环富集比较严重的区域有二个:一是窑尾烟室及上升烟道区,二是次末级和最末级预热器。其中前者与碱和硫关系较大,而后者与氯关系较大。

The volatilities and equilibrium of alkali（K）,chlorine and sulfur were calculated in the temperature range from 500℃ to 1400℃ according to Gibbs free energy minimization method,the circulation and enrichment of alkali（K）,chlorine and sulfur were also discussed combined with the temperature distribution in the cement kilns.The results showed that the volatility of chlorine increases abruptly in the range of 650℃ to 800℃,and reaches almost 100% above 800℃.Sulfur and alkali volatilize completely at about 1300℃ and the volatilities increase abruptly in the range of 1000℃ to 1200℃.Increasing the content of chlorine can promote the volatilization of sulfur and alkali,especially at relatively lower temperatures between 650℃ and 800℃.The circulation and enrichment occur comparative seriously in two regions,one is the kiln hot end and the rise-pipe,another one is the stage next to the last stage and the last stage preheaters.The former is closely related with alkali and sulfur,while the latter is closely related with chlorine.