热处置CFB焚烧飞灰作混合材对水泥性能的影响

Effect of Thermal Treatment CFB Incineration Fly Ash as Admixture on Cement Properties

在使用循环流化床(CFB)焚烧技术处置城市生活垃圾过程中,会产生大量垃圾焚烧飞灰(简称CFB灰),它是Cu、Zn、Cr、Pb等重金属离子浸出和二噁英含量超标的危险固废,不经安全处置不能直接填埋或资源化利用。故此,本文研究了热处置对CFB灰用作水泥混合材的改性效果,结果表明:CFB灰直接用作水泥混合材的火山灰活性很低,仅为21.68%;所含少量Al单质的反应会导致水泥浆体膨胀,氯盐和二噁英含量高不符合作为水泥混合材要求;经1200℃,60min热改性后,火山灰活性提高至65.89%,氯离子和二噁英含量降低至1.08%和0.98ng TEQ/kg,当掺量不大于10%时满足制备P·O42.5水泥要求。

In the process of using circulating fluidized bed(CFB)incineration technology to dispose of waste,a large amount of waste incineration fly ash(CFB ash)is generated.It is a hazardous solid waste that leaches heavy metal ions such as Cu,Zn,Cr,Pb,and has excessive dioxin content.Without safe disposal,it cannot be directly landfilled or utilized as a resource.Therefore,this paper studies the modification effect of heat treatment on CFB ash used as a cement admixture.The results showed that pozzolanic activity of CFB ash directly used as cement admixture is only 21.68%;The reaction of a small amount of Al generated hydrogen,cause the cement to expand.The high content of chloride and dioxin did not meet the requirements of cement additives;After thermal modification at 1200℃for 60 min,the pozzolanic activity is 65.89%,chloride ion and dioxin was reduced to1.08%and 0.98 ng TEQ/kg.When the content was less than 10%,it meeted the requirements for preparing P·O42.5 cement.