燃煤过程中As、Se、Sb释放与迁移规律研究

Study on the release and migration of arsenic,selenium and antimony during coal combustion

以安徽淮南煤田深部山西组煤样为研究对象,通过设计不同燃烧温度条件,测定各温度下燃煤产物中有害元素含量,拟合得到As、Se、Sb的释放曲线与释放强度曲线,并对原煤及不同温度条件下燃煤产物中各元素的赋存状态进行分析。结果表明,燃烧温度由500℃升至1000℃过程中,As、Se、Sb的释放比例逐渐增大,三种有害元素挥发性难易程度顺序表现为Se>As>Sb;不同温度下有害元素释放强度不同,As在700~815℃的区间内出现一个释放强度峰,而Se与Sb的释放强度峰出现在600~700℃阶段;随燃煤温度不断升高,As、Se、Sb的各赋存形态均发生不同程度的迁移及转化,温度升高至1000℃,As、Se、Sb的固相形态明显降低。

The coal samples from the Shanxi Formation in the Huainan Coalfield of Anhui Province were used as research objects.By designing different combustion temperature conditions,the content of harmful elements in coal-fired products at different temperatures was determined,and the release curves and release intensity curves of As,Se and Sb were fitted.Analysis of the occurrence status of harmful elements in raw coal and coal products at different temperatures.The results showed that:The release ratio of As,Se and Sb increases gradually when the combustion temperature rises from 500℃to 1000℃.The order of volatility of three harmful elements is as follows:Se>As>Sb;The release intensity of harmful elements is different at different temperatures,and a release intensity peak appears between 700℃and 815℃,while the release of Se and Sb the intensity peak appears at the stage of 600~700℃;As the temperature of coal combustion increases,the occurrence forms of As,Se and Sb undergo different degrees of migration and transformation,and the temperature rises to 1000℃,the solid phase morphology of As,Se and Sb decreased significantly.