垃圾焚烧飞灰熔制微晶玻璃固定化与资源化研究  

Stabilization of MSWI Fly Ash by Glass-ceramics Recycling Process

作　　者：杨家宽[1] 肖明丹[1] 周敏[1] 何宝平[1] 张杜杜[1] 肖波[1] 

机构地区：[1]华中科技大学环境科学与工程学院,湖北武汉430074

出　　处：《玻璃与搪瓷》2007年第3期1-5,20,共6页Glass & Enamel

基　　金：华中科技大学研究生基金资助项目(Z0325)

摘　　要：垃圾焚烧飞灰因含有重金属和二恶英等物质而被列为危险固废。在研究广东省某垃圾焚烧厂产生的飞灰的化学组成和矿物组成的基础上,制备了飞灰基础玻璃和微晶玻璃。通过DSC、XRD、SEM等手段研究了飞灰基础玻璃的晶化特性、微晶玻璃样品的矿物组成和显微结构,并对飞灰样品、水泥固化体及玻璃固化体的浸出毒性进行了对比研究。结果表明:飞灰的主要化学组成为SiO2、CaO、Al2O3、Fe2O3和MgO,它们都是制备玻璃所需的化学成份,外加少量石英砂和添加剂可熔制出性能稳定的基础玻璃和微晶玻璃。基础玻璃的转化温度Tg为700℃,在700℃核化2 h,不同晶化温度下热处理获得微晶玻璃样品。随着晶化温度的升高,部分晶粒明显粗化,且晶体组织变疏松。飞灰微晶玻璃的主晶相为透灰石体系[Ca(Mg,Fe,Al)(Si,Al)2O6]。飞灰浸出液中重金属Cd严重超标,水泥固化体和玻璃固化体重金属浸出毒性均符合安全标准,且玻璃固化体浸出毒性较水泥固化体低一个数量级。Municipal solid waste incineration （MSWI） fly ash is classified as hazardous solid waste because of a lot of heavy metals and dioxins in it. Fly ash samples were taken from an incineration power plant in Guangdong province, which is the first solid waste power plant with the rotary kiln process developed by themselves in China. Based upon analyses of chemical and mineral compositions of fly ash samples, the matrix glasses and glass - ceramics have been made from fly ash with some additives. The crystallization of the matrix glasses, crystalline phase and microstructural characteristics of glass - ceramics have been investigated by DSC, XRD and SEM. The leachate properties of fly ash samples, solidified body by cement and solidified body by molten glass have been studied respectively. The results show that the chemical compositions of MSWI fly ash are comprised of SiO2, CaO, Al2O3 ,Fe203 and MgO, all of which are also the necessary chemical components for glass. Due to the above mentioned facts the glass and glass -ceramics can be made from fly ash successfully. The transition temperature Tg of matrix glass is about 700 ℃. The different glass - ceramic samples are treated at the fixed nucleation temperature 700℃ for 2h followed by heat - treatment at various crystallization temperatures. With the increase of crystallization temperatures, a part of crystals grow into column crystals larger than 300 - 400nm, and microstructure of glass -ceramics becomes sparse. The major crystalline phase was diopside. The leaching value of Cd in MSWI fly ash is higher than the national standard. The leaching values of heavy metals of solidified body by cement and molten glass are far lower than that of the national standard in China, and the leaching value of heavy metals of solidified body by glass is one order of magnitude lower than that of solidified body by cement.

关 键 词：垃圾焚烧飞灰 微晶玻璃 浸出毒性 重金属 固废处置 

分 类 号：TQ171.418[化学工程—玻璃工业]