【摘要】 对两个电厂的原煤、底灰、飞灰和超细飞灰(≤10μm)进行了有害微量元素含量的测定,研究了As、Cd、Cr、Pb、Se、Mo、Ni、Be、Cu、Th、U、V、Zn、Hg等14种元素在煤燃烧过程中的散逸、迁移行为,揭示了它们在燃煤过程中在气态产物和固态产物(底灰、飞灰、超细飞灰)中的分配富集特征,分析了这些元素的环境效应。结果表明:在两电厂中,元素Cd、Pb、Zn富集系数由大到小为超细飞灰>飞灰>底灰;As的分布特性与煤中Ca的含量密切相关;较低的烟气温度能够使部分气态Hg在飞灰颗粒上发生凝结;将几种元素分为3类:Ⅰ类,留在固体废物中的元素V(QR>0.85);Ⅱ类,部分留在固体废物中的元素As、Cd、Cr、Pb、Se、Mo、Ni、Be、Cu、Th、U、Zn(0.85≥QR>0.10),其中As、Cr、Ni、Be、Cu、Th的富集程度较强,Zn、Mo、Se、Cd较弱;Ⅲ类,主要挥发到大气中的元素Hg(QR接近0)。更多还原

【Abstract】 Some hazardous trace elements in raw coal,bottom ash,fly ash,and superfine fly ash(≤10 μm) from two power plants were tested.Burning and migration behabivor of As,Cd,Cr,Pb,Se,Mo,Ni,Be,Cu,Th,U,V,Zn,Hg were researched and their distribution and enriching characteristic in coal,bottom ash,fly ash and superfine fly ash were analyzed.The results show that for elements Cd,Pb,Zn in the two power plants,the enrichment coefficients,from great to small,are in the order of superfine ash,fly ash,bottom ash.The distribution of As is related with the content of Ca.Lower temperatures of flue gas can make part of the gaseous Hg coagulate on the fly ash particles.The hazardous elements were classified into three categories:Ⅰ,element V,stays in the solid wastes(QR > 0.85) ;Ⅱ,As,Cd,Cr,Pb,Se,Mo,Ni,Be,Cu,Th,U,Zn,partly leave in solid wastes(0.85≥QR > 0.10) ;Ⅲ,Hg,mainly volatilizes into the atmosphere(QR close to 0).更多还原