Development of Foamed Geopolymer with Addition of Municipal Solid Waste Incineration Fly Ash
Development of Foamed Geopolymer with Addition of Municipal Solid Waste Incineration Fly Ash
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DOI：
10.3151/jact.19.830
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发表时间：
2021-07-01
影响因子：
2
通讯作者：
Ikeda, Ko
中科院分区：
文献类型：
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作者：
Li, Zhuguo;Kondoa, Ryusei;Ikeda, Ko
为了开发垃圾焚烧飞灰（MSWI-FA）的安全再生利用技术，作者尝试了添加MSWI-FA制备泡沫地质聚合物，并对其堆密度、强度、导热系数、重金属和氯的浸出浓度等性能进行了研究。通过X射线衍射（XRD）和扫描电子显微镜（SEM）分析了晶体化合物和微观结构。已发现，通过添加金属铝粉作为发泡剂并使用小于20%的MSWI-FA和具有低NaOH摩尔浓度的合适的碱活化剂，可以生产具有小于0.5的堆积密度和均匀分布的空气空隙的发泡地质聚合物。CaCl（OH）（2）、Ca（OH）（2）、CaO和KCl最初包含在MSWI-FA中，但在发泡地质聚合物中没有发现。以磨细矿渣、粉煤灰和MSWI-FA为前驱体制备的地聚合物主要由C-A-S-H凝胶、未完全反应的前驱体和少量的N-A-S-H凝胶组成。泡沫地质聚合物对重金属（Cd、Cr、Cu、Mn、Pb、Zn）具有很高的固定能力，且不随渗滤液pH值的变化而变化。As的固定效率随渗滤液pH和BFS含量的变化而变化。当BFS含量不低于60%时，包括As在内的所有痕量重金属的浸出浓度都很低，满足日本再生建筑材料不直接接触水的环境标准。泡沫地质聚合物的氯固定能力预计在长期老化中超过70%。
In order to develop a safe technology for recycling municipal solid waste incineration fly ash (MSWI-FA), the authors have attempted to produce foamed geopolymers with addition of MSWI-FA, and have investigated their various properties, including bulk density, strength, thermal conductivity, and leaching concentration of heavy metals and chlorine, etc. The polymerization reaction products, crystalline compounds and microstructure were also examined through X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analyses. It was found that it is possible to produce foamed geopolymer with a bulk density of less than 0.5 and a uniform distribution of air voids, by adding metallic aluminum powder as foaming agent and using less than 20% MSWI-FA and suitable alkali activator having low NaOH mole concentration. CaC1(OH)(2) Ca(OH)(2), CaO and KCl, initially included in the MSWI-FA, were not found in the foamed geopolymers. The geopolymers, which used ground granulated blast furnace slag (BFS), coal fly ah and MSWI-FA as precursors, were mainly composed of C-A-S-H gels, incompletely reacted precursors and a small amount of N-A-S-H gels. The foamed geopolymer had very high immobilization capacity of heavy metals (Cd, Cr, Cu, Mn, Pb, Zn), not varying with the pH of leachate. The immobilization efficiency of As changed with the pH of leachate and BFS content. When the BFS content was not less than 60%, the leaching concentrations of all the traced heavy metals including As were low, satisfying the environmental criteria of Japan for recycled construction materials without direct contact with water. The chlorine immobilization capacity of the foamed geopolymers is expected to exceed 70% in long-term age.