Optimizing critical metals recovery and correlative decontamination from MSWI fly ash: Evaluation of an integrating two-step leaching hydrometallurgical process
Journal article, 2022
While municipal solid waste incineration (MSWI) fly ash is classified as hazardous waste, it can also serve as an urban mining source for numerous precious metals. Of particular interest are antimony (Sb) and zinc (Zn); the former of which is a strategic and critical metal that is being rapidly depleted, putting society at high risk for supply shortages. In this work, a two-step leaching method for recovering Sb and Zn from MSWI fly ash is proposed. Furthermore, the leaching behavior and adsorption mechanism of Sb in the MSWI fly ash waste stream were also investigated. Results from the first constant pH leaching tests (CPLT) showed that under diluted acidic condition, the maximum amount of Sb released from fly ash was ∼20%. In addition, at pH 4.0, 67% of the fly ash was dissolved, while 79.3% and 12.1% of the Zn and Sb, respectively, were recovered. After optimizing and executing a second Sb leaching procedure (6 M HCl solution at 60 °C), >80% of the Sb was recovered. Thus, the proposed two-step leaching process, consisting of extraction followed by decontamination using a magnetic HAP@CoFe2O4 adsorbent, can eliminate the Sb in fly ash effluent with a removal efficiency >95%. Moreover, this process produces less toxic products and lowers the effluent residue concentration. As such, the two-step process described herein is suggested for Sb and Zn recovery from fly ash; as it not only enables precious metal recovery, but also aids in treating secondary waste streams produced from urban mining.
Author
Jinfeng Tang
Linköping University
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Chalmers, Chemistry and Chemical Engineering, Energy and Material
Shaobin Dong
Linköping University
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Qian Feng
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Linköping University
Minhua Su
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Linköping University
Yongjun Wei
Zhengzhou University
Jiawei Liang
Zhengzhou University
Hongguo Zhang
Linköping University
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Lei Huang
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Linköping University
Lingjun Kong
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Linköping University
Nana Wang
Linköping University
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Enzong Xiao
Linköping University
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Yingkui Liu
XuZhou Medical University
Xuan Tang
Guangzhou University
Tangfu Xiao
Linköping University - Guangzhou University Research Center on Urban Sustainable Development
Linköping University
Journal of Cleaner Production
0959-6526 (ISSN)
Vol. 368 133017Subject Categories
Chemical Process Engineering
Other Chemistry Topics
Bioenergy
DOI
10.1016/j.jclepro.2022.133017