焚烧飞灰结构表征及烧结固化体重金属稳定化  

Delicate characterization of MSWI fly ash and study on stabilization mechanism of heavy metals with sintering solidification

作　　者：刘锡宇 曹海琳 翁履谦 汪谢庚 LIU Xi-yu;CAO Hai-lin;WENG Lv-qian;WANG Xie-geng(School of Materials Science and Engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China;Shenzhen Aerospace New Material Technology Co.,Ltd,Shenzhen 518075,China)

机构地区：[1]哈尔滨工业大学(深圳)材料科学与工程学院,广东深圳518055 [2]深圳市航天新材科技有限公司,广东深圳518057

出　　处：《中国环境科学》2023年第S1期160-169,共10页China Environmental Science

基　　金：深圳市基础研究(重点项目)(JCYJ20220818102402006)

摘　　要：通过元素分析(XRF)、X-射线衍射分析(XRD)、热重-差热分析(DSC)以及扫描/透射电镜分析(SEM/TEM)对垃圾焚烧(MSWI)飞灰进行了表征,采用成分调控烧结一定比例的MSWI飞灰、粉煤灰和水玻璃混合物固化MSWI飞灰中的重金属,通过理论建模和试验研究了烧结样品中重金属Pb、Cd、Zn的固化机理.Materials Studio能量模拟计算结果表明,重金属Pb、Cd和Zn可取代烧结样品晶相硅灰石结构中的Ca离子,具有能量增益.XRD分析结果证实,重金属掺入后硅灰石的晶格参数发生了相应的变化.Tessier提取试验结果表明,与MSWI原灰相比烧结处理后的固化体残渣晶格态含量增大,说明烧结固化处理后飞灰中的重金属稳定性显著提高.在热处理过程中,混合固化体中的重金属挥发率低于原灰.优化MSWI飞灰、粉煤灰和水玻璃配比,经相对低温(900℃)处理可以获得具有理想强度的飞灰陶粒制品,这一探索为MSWI飞灰资源化制备建筑材料的可行性提供了试验依据.The MSWI fly ash was finely characterized by element analysis,XRD,DSC and TG-MS,SEM and TEM respectively.The solidification mechanism of heavy metals Pb,Cd and Zn in MSWI fly ash was studied through theoretical modelling and experiment by using the mixture of MSWI fly ash,fly ash and water glass with certain proportion of composition control sintering.The energy simulation calculation carried out by Materials Studio instructed that Pb,Cd,and Zn could replace Ca in the cell structure of wollastonite,the main phase in the final products,with energy benefit.The cell parameters of wollastonite were altered accordingly,which was confirmed by XRD analysis.The results of the Tessier extraction test elucidated that the sintered products have significantly large amount of the residue lattice phases,comparing with untreated MSWI fly ash,indicating the substantial improvement of the heavy metals stability in the sintered products.The study also found that the heavy metals had less volatilization ability in the solidified products than in the MSWI fly ash during heat treatment process.The MSWI fly ash ceramists,with satisfying mechanical features,were finally obtained with an optimal ratio of the MSWI fly ash,coal fly ash and sodium silicate solutions after a relatively low temperature treatment(900℃),which provides a feasible process to use MSWI fly ash as building materials.

关 键 词：生活垃圾焚烧飞灰 重金属固化 烧结陶粒 硅灰石 

分 类 号：X799.3[环境科学与工程—环境工程]