燃烧温度对粉煤灰理化特性及脱硫潜力的影响

Effect of combustion temperature on physico-chemical properties and desulphurization potentiality of fly ash

为了获得高脱硫活性的粉煤灰,采用滴管炉试验装置,结合扫描电子显微镜、粒度分析仪、X射线衍射仪、X射线光电子能谱仪及化学滴定等测试仪器和方法,对不同燃烧温度所获得粉煤灰的物相形貌、化学组成和活性氧化钙含量等特性进行了研究,探究了煤粉燃烧温度对粉煤灰特性的影响规律。结果表明:燃烧温度对粉煤灰物相形貌、化学形态、固硫率及活性氧化钙含量均有显著影响,随温度升高,不规则形态颗粒的数量逐步减小,颗粒尺寸微增,CaO和Ca(OH)_2含量逐渐增加,烟气中SO_2排放浓度呈现先升高后平缓的趋势,活性氧化钙含量逐渐增高,可有效提高粉煤灰作为脱硫剂的脱硫潜力。综合分析,燃烧温度800℃左右为煤粉最佳燃烧工况。

In order to obtain fly ash with high desulfurization activity,in combination with scanning electron microscope（ SEM）,particle size analyzer,X-ray diffractometer（ XRD）,X-ray photoelectron spectrometer（ XPS）,chemical titration and other characterization methods,the dropper tube furnace was used to study the phase morphology,chemical components of fly ash and active CaO content obtained from pulverized coal combustion with different combustion temperatures. The influence law of coal combustion temperature on the characteristics of fly ash was investigated. The results showed that the combustion temperature had significantly affected on the phase morphology of fly ash,chemical composition,sulfur fixation rate and the content of active calcium oxide. With the temperature increased,the number of irregular shape particles gradually decreased,and particle size increased,the contents of CaO and Ca（OH）_2 increased,the content of SO_2 showed a trend of rise before they were gentle,the content of active calcium oxide increased gradually,which could effectively improve the fly ash as desulfurizer desulfurization of potential. By comprehensive analysis,the temperature about 800 ℃ was the best combustion conditions.