层燃炉燃煤中9种微量元素的迁移

Removal of 9 Kinds of Trace Element in Burning Coal in the Layer-Burning Boilers

建立了层燃锅炉底灰、飞灰中Ｂｅ、Ｃｏ、Ｃｒ、Ｃｕ、Ｍｎ、Ｎｉ、Ｐｈ、Ｖ、Ｚｒ含量与煤中这９种元素含量关系的经验公式，估算了煤中微量元素在底灰、飞灰和排入大气的烟气中的总量分配．研究了飞灰中元素含量和总量的粒度分布，探讨了煤炭燃烧过程中元素的集散规律．底灰中多数元素含量高于飞灰，燃煤中９种元素大部分迁移到底灰中．但飞灰中元素的富集因子高于底灰，元素富集程度随粒径减小而增加，飞灰中元素总量集中于＜０．１２５ｍｍ粒径的粒子上．

An empirical formula on the content of trace elements as Be,Co,Cr,Cu,Mn,Ni,Pb,V,Zr in fly ash and bottom ash of burning coal in layerburning boilers was developed,by which the distribution and transfer quantity of trace elements from coal into fly ash,bottom ash and atmosphere was calculated.The grain size distribution of content and mass of trace elements in fly ashes was also studied,and the laws of enrichment or dispersion of trace elements in burning process were approached.The content of most of trace elements in bottom ashes is higher than that in fly ashes,most quantity of 9 trace elements in coal is removed into bottom ash after burning,but the enrichment factor of element in fly ashes is higher than that in bottom ashes.The enrichment extent of trace elements in fly ashes increases as grain size decreases.About 90 percent of total quantity of trace elements in fly ashes are distributed in the particles with the diameter less than 0.125 mm.