火电厂粉煤灰中重金属元素的分布和富集特性  

Characteristics of Distribution and Enrichment of Heavy Metal Elements in Fly Ash from Coal-burning Electric Power Plant

作　　者：刘楷[1] 杨常亮[2] 李世玉[2] 余洋洋[3] 刘彬[2] 陈桂明[1] 王艳丹[1] 

机构地区：[1]云南大学生命科学学院 [2]云南大学工程技术研究院 [3]云南大学城市建设与管理学院,云南昆明650091

出　　处：《环境科学与技术》2015年第12期145-150,共6页Environmental Science & Technology

基　　金：国家自然科学基金(51168047)

摘　　要：将取自火电厂的2种燃煤燃烧后不同电场捕获到的粉煤灰依次过筛,分选为不同粒径组份,并检测分析各粒径组分中重金属元素含量,研究了火电厂褐煤和烟煤粉煤灰中As、Hg、Cu、Pb、Zn、Cd 6种元素在不同粒径组分中的分布与富集特性。烟煤和褐煤燃烧产生的粉煤灰粒径组份有差异。As、Cu、Pb、Zn、Cd随粉煤灰粒径的增大而含量降低。Hg元素由于挥发性较高,其分布与粒径大小无相关性。褐煤粉煤灰中各重金属元素富集程度从大到小依次为Cd>Pb>Zn>As>Cu;烟煤粉煤灰中各重金属元素富集程度从大到小依次为As>Cd>Zn>Pb>Cu。静电除尘器对褐煤燃烧产生的粉煤灰中Cd元素有较好的去除率,对于烟煤粉煤灰中的As和Cd元素排放有较好的去除率。相对于褐煤,燃烧烟煤可以更好的控制As排放,建议火电厂优先使用烟煤。The samples of fly ash captured by a static electricity precipitator and collected in different electric fields from burning two different kinds of coal （lignite and bituminous） in a coal-burning electric power plant were investigated. Ash samples were sieved in proper order and sorted into different-particle-size groups, and thereafter analysis of each group ash was conducted for measuring the content of heavy metal elements including Hg, Cu, Pb, Zn and Cd in the components of different particle size. The investigation showed that particle-size groups of fly ashes from lignite and bituminous coal were different; bigger particle size usually contain less content of the elements of As, Hg, Cu, Pb, Zn and Cd except Hg due to its high volatility. The degree of enrichment of heavy metals in fly ash of lignite was in descending order： Cd〉Pb〉Zn〉As〉 Cu, while for bituminous coal： Cd〉Pb〉Zn〉As〉Cu. Besides, Cd in fly ash of lignite was removed better by static electricity precipitator, while the removal of As and Cd elements was better in the fly ash of bituminous coal. Thus compared with lignite, use of bituminous coal as a fuel in coal-burning electric power plant would be better in control of As emission.

关 键 词：褐煤 烟煤 粉煤灰 金属元素 相对富集系数 

分 类 号：X773[环境科学与工程—环境工程]