Song Zhijun, Zhang Xiaowen, Tan Yujiao, Zeng Qin, Hua Yilong, Wu Xiaoyan, Li Mi, Liu Xudong, Luo Mingliang
School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, China.
School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, China; Hengyang Key Laboratory of Soil Pollution Control and Remediation, University of South China, Hengyang, 421001, China.
J Environ Manage. 2023 Mar 1;329:117074. doi: 10.1016/j.jenvman.2022.117074. Epub 2022 Dec 29.
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.
资源化为城市生活垃圾焚烧飞灰（MSWI FA）的最终处置提供了一个热门的研究课题。然而，目前的研究仅限于建筑材料制备或有价值氯化物的回收，这可能会导致资源浪费和二次污染。本文提出了一种独特的工艺，即添加高岭土（KL）进行热处理，以实现MSWI FA的完全资源利用。添加KL可以改善陶粒的物理性能，通过在1150℃下烧结可以实现二噁英去除、重金属和有价值氯化物的分离。通过湿法分离实现了热处理过程中烟气携带粉尘（二次飞灰）的分离与净化。获得了抗压强度为24.8MPa的建筑陶粒，而二噁英和重金属毒性远低于标准限值。二次飞灰分离与净化后，重金属含量富集了12倍，约为59.6%。得到了含39.5%Zn、19.1%Pb的重金属产品和含41.8%KCl的氯盐。这表明所开发的工艺具有从飞灰中分离多种有价元素的巨大潜力。这种新工艺将进一步推动MSWI FA无害化和资源化技术的发展与应用。
