粒径对燃煤电站飞灰元素质量分数分布的影响

摘要

对燃煤电站不同粒径飞灰样品进行了扫描电镜、X射线衍射、电子探针和离子色谱分析,研究了燃煤飞灰中元素质量分数随飞灰粒径的变化规律,分析了过量空气系数对飞灰中元素质量分数分布的影响,并将其与电加热沉降炉的试验结果进行了比较.结果表明:Na、S、Ca和Cl元素的质量分数分布随粒径改变整体上呈负相关变化；Al、Si、K和Fe的质量分数分布随粒径改变整体上呈正相关变化；粒径为25～45 μm飞灰中元素的质量分数分布随过量空气系数的变化呈现明显的规律性,而粒径＞45～75 μm飞灰中元素的质量分数分布随过量空气系数变化的规律不明显；在200～350℃时,加热温度对飞灰中Cl和S元素的质量分数分布无影响.%Scanning electron microscopy,X-ray diffraction analysis,electron probe analysis and ion chromatography analysis were carried out to fly ash samples with different particle sizes from coal-fired power plants,so as to study the variation law of element mass fraction with the particle size of fly ash,and to analyze the influence of excess air coefficient on the distribution of element mass fraction.Above results were subsequently compared with the experimental data of a drop tube furnace.Results show that the mass fraction distribution of Na,S,Ca,and Cl changes basically in a negative correlation with the variation of particle size,whereas that of Al,Si,Ka and Fe changes in a positive correlation; the variation law of mass fraction distribution with excess air coefficient is obvious for particle sizes in 25-45 μm,which is not obvious for particle sizes greater than 45-75 μm; in the range of 200-350 ℃,the heating temperature has no effect on the mass fraction distribution of elements Cl and S in fly ash.