An all-in-one strategy for municipal solid waste incineration fly ash full resource utilization by heat treatment with added kaolin. (1st March 2023)

• Record Type: Journal Article
• Authors: Song, Zhijun; Zhang, Xiaowen; Tan, Yujiao; Zeng, Qin; Hua, Yilong; Wu, Xiaoyan; Li, Mi; Liu, Xudong; Luo, Mingliang
• Is Part Of: Journal of environmental management. Volume 329(2023)
• Publication Date: 2023-03-01
• Subjects: Municipal solid waste incineration fly ash -- Heavy metals -- Ceramsite -- Heat treatment; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.117074
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Resourcization has become a popular research topic for the final disposal of municipal solid waste incineration fly ash (MSWI FA). However, the current research is limited to building material preparation or valuable chloride recovery, which may cause resource waste and secondary pollution. A unique process, heat treatment with the addition of kaolin (KL), was presented to achieve complete resource utilization of MSWI FA. The physical properties of ceramsite could be improved by adding KL, and dioxin removal, heavy metals, and valuable chloride separation could be achieved via sintering at 1150 °C. The separation and purification of dust carried by the flue gas during thermal treatment (secondary fly ash) was achieved via wet separation. A building ceramsite with a compressive strength of 24.8 MPa was obtained, whereas dioxin and heavy metal toxicity were far below the standard limits. Heavy metal content was enriched by 12 times, approximately 59.6%, achieved after secondary fly ash separation and purification. A heavy metal product containing 39.5% Zn, 19.1% Pb, and chloride salt containing 41.8% KCl were obtained. This showed a high potential for the developed process to separate multiple valuable elements from ashes. This novel process will further promote the development and application of harmless and resourceful technologies for MSWI FA. Graphical abstract: Image 1 Highlights: Heat treatment eliminated heavy metals and dioxin of MSWI FA to non-hazardous waste. Heat treatment with kaolin attains complete resource utilization of MSWI FA. The technological process of complete resource utilization of MSWI FA is proposed.