Leaching law of heavy metals in coal gangue: A combination of experimental optimization and simulation

Hualin Zhang; Qiong Li; Mengfei Zhao; Youming Yang; Renbi Bai; Xiaoliang Jiang; Tinggang Li

doi:10.1016/j.jhazmat.2024.136790

Leaching law of heavy metals in coal gangue: A combination of experimental optimization and simulation

J Hazard Mater. 2025 Feb 15:484:136790. doi: 10.1016/j.jhazmat.2024.136790. Epub 2024 Dec 4.

Authors

Hualin Zhang¹, Qiong Li², Mengfei Zhao¹, Youming Yang³, Renbi Bai⁴, Xiaoliang Jiang⁵, Tinggang Li⁶

Affiliations

¹ Key Laboratory of Rare Earths, Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China; School of Metallurgical engineering, Jiangxi University of Science and Technology, Ganzhou 341099, China.
² Key Laboratory of Rare Earths, Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China; School of Rare Earths, University of Science and Technology of China, Hefei 230026, China.
³ School of Metallurgical engineering, Jiangxi University of Science and Technology, Ganzhou 341099, China.
⁴ Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou 215009, China.
⁵ Key Laboratory of Rare Earths, Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China. Electronic address: xljiang@gia.cas.cn.
⁶ Key Laboratory of Rare Earths, Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China; CAS Key Laboratory of Green Process and Engineering, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Innovation Academy for Green Manufacture, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Metallurgical engineering, Jiangxi University of Science and Technology, Ganzhou 341099, China; School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; State Key Laboratory of Biochemical Engineering, Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: tgli@ipe.ac.cn.

PMID: 39644856
DOI: 10.1016/j.jhazmat.2024.136790

Abstract

Coal gangue, a solid waste generated during coal mining and washing processes, has caused significant environmental burdens in China. This study aims to optimize and investigate the leaching mechanisms of heavy metals, such as Pb, Zn, and Cu, in coal gangue. The effectiveness of different eluents in removing heavy metals from coal gangue was evaluated by combining experimental methods with software simulations. The leaching conditions (EDTA-2Na concentration of 5 g/L, pH 3, solidliquid ratio of 1:10, leaching time of 4 h, 300 r/min) were optimized to achieve efficient and economical removal of heavy metals. Box-Behnken Design was used to show the key factors of eluant concentration and solid-liquid ratio. The leaching amounts of Pb, Zn, and Cu from coal gangue using EDTA-2Na as a leaching agent were 86 mg/kg, 430 mg/kg, and 66 mg/kg, respectively. The release mechanism and kinetic behavior of heavy metals in the leaching process were studied. The study provided information about leaching mechanisms of heavy metals from coal gangue by experiments and simulations of Visual MINTEQ and DFT that EDTA-2Na enhanced the leaching of heavy metals from coal gangue by enhancing ion exchange and complexation.

Keywords: Coal gangue; DFT calculation; EDTA−2Na; Heavy metal leaching; Visual MINTEQ simulation.