1.School of Chemical and Environmental Engineering,China University of Mining and Technology (Beijing),Beijing ,China;2.China Coal Research Institute,Beijing ,China;3.Coal Chemical Research Institute,China National Coal Group Co.,Ltd.,Beijing ,China

为提高粉煤灰烟气脱硫性能，采用滴管炉实验装置，结合扫描电镜（SEM）、粒度分析仪、X射张衍射分析（XRD）、X射线光电子能谱（XPS）、热重分析、化学分析等测试手段，对添加不同比例固硫剂（钙硫比）时所获得粉煤灰的脱硫性能和煤粉燃烧特性进行了研究，并通过粉煤灰的物理形貌、化学组成、活性氧化钙含量等方面的变化对其结果进行验证分析。结果表明：钙硫比对粉煤灰脱硫性能和煤粉燃烧特性均有一定的影响，随钙硫比增加，炉内固硫率增大，在0～1.0和2.0～2.5时，固硫率增长缓慢，粉煤灰脱硫性能增强，钙硫比为3.0时外加的固硫剂过量导致与钙硫比为2.0和1.5时脱硫性能大致相同；粉煤灰大粒径颗粒比例减小，CaO和Ca(OH)2含量逐渐增大，活性CaO含量持续增长（钙硫比在1.5～2.0，趋势渐缓），活性CaO是脱硫反应的主要成分，煤粉燃烧残余量逐渐增大，发热量依次降低，灰熔点先降低后升高，钙硫比为1.0时灰熔点最低，钙硫比大于1.5时灰熔点逐渐上升。综合脱硫性能、燃烧特性和经济性3方面因素，钙硫比选取1.5为最宜配比。

In order to improve the desulphurization performance of fly ash in flue gas, the dropper tube furnace was used, in combination with SEM, particle size analysis, XRD, XPS, thermogravimetric curve and chemical analysis and other methods, the authors investigated the effect of different sulfur-fixing agent dosage(calcium-sulfur ratio) on desulfurization performance of fly ash and combustion characteristics of pulverized coal. Meanwhile, the changes in the physical morphology, chemical composition and active calcium oxide content of fly ash were studied to verify the influence results. The results show that the ratio of calcium to sulfur has a certain effect on the desulfurization performance of fly ash and the combustion characteristics of pulverized coal. With increasing the ratio of calcium-sulfur, the sulfur fixation rate grows，the growth rate will be slow when calcium-sulfur ratio is between 0～1 and 2.0～2.5, fly ash desulfurization performance is enhanced. The desulfurization performance will be roughly the same when calcium-sulfur ratio is 3.0(excessive sulfur-fixing agent dosage) and 2.0 and 1.5. The proportion of large particle size of fly ash decreases,CaO and Ca(OH)2 content gradually increase, active calcium oxide content continues to increase, the trend will gradually diminish, when the calcium-sulfur ratio is in the range of 1.5～2.0. Active calcium oxide is a main component in the desulfurization’s reaction. The remain component of pulverized coal combustion gradually increase, and the calorific value is gradually reduced. The ash melting point initially decreases and then increases (the ash melting point will be the lowest position when calcium-sulfur ratio is 1.0, and the ash melting point will gradually increase when calcium-sulfur ratio is greater than 1.5. Based on the three factors, desulfurization performance, combustion characteristics and economics, 1.5 is the most appropriate rate of calcium-sulfur ratio.