title: Bioleaching combined brine leaching of heavy metals from lead-zinc mine tailings: Transformations during the leaching process.
abstract: During the process of bioleaching, lead (Pb) recovery is low. This low recovery is caused by a problem with the bioleaching technique. This research investigated the bioleaching combination of bioleaching with brine leaching to remove heavy metals from lead-zinc mine tailings. The impact of different parameters were studied, including the effects of initial pH (1.5-3.0) and solid concentration (5-20%) for bioleaching, and the effects of sodium chloride (NaCl) concentration (10-200 g/L) and temperature (25 and 50 °C) for brine leaching. Complementary characterization experiments (Sequential extraction, X-ray diffractometer (XRD), scanning electronic microscope (SEM)) were also conducted to explore the transformation of tailings during the leaching process. The results showed that bioleaching efficiency was significantly influenced by initial pH and solid concentration. Approximately 85.45% of iron (Fe), 4.12% of Pb, and 97.85% of zinc (Zn) were recovered through bioleaching in optimum conditions. Increasing the brine concentration and temperature promoted lead recovery. Lead was recovered from the bioleaching residues at a rate of 94.70% at 25 °C and at a rate of 99.46% at 50 °C when the NaCl concentration was 150 g/L. The study showed that bioleaching significantly changed the speciation of heavy metals and the formation and surface morphology of tailings. The metals were mainly bound in stable fractions after bioleaching.
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; Key Laboratory of Mining and Metallurgy Industry Heavy Metals Pollution Control of Environmental Protection of Guangdong Province, Guangzhou 510006, China.
authors.forename: Maoyou
authors.initials: M
authors.lastname: Ye
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; Key Laboratory of Mining and Metallurgy Industry Heavy Metals Pollution Control of Environmental Protection of Guangdong Province, Guangzhou 510006, China.
authors.forename: Pingfang
authors.initials: P
authors.lastname: Yan
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; Guangdong Polytechnic College of Environmental Protection Engineering, Foshan 528216, China; Key Laboratory of Mining and Metallurgy Industry Heavy Metals Pollution Control of Environmental Protection of Guangdong Province, Guangzhou 510006, China. Electronic address: sysun@gdut.edu.cn.
authors.forename: Shuiyu
authors.initials: S
authors.lastname: Sun
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Dajian
authors.initials: D
authors.lastname: Han
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Xiao
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; Key Laboratory of Mining and Metallurgy Industry Heavy Metals Pollution Control of Environmental Protection of Guangdong Province, Guangzhou 510006, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zheng
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; Key Laboratory of Mining and Metallurgy Industry Heavy Metals Pollution Control of Environmental Protection of Guangdong Province, Guangzhou 510006, China.
authors.forename: Shaosong
authors.initials: S
authors.lastname: Huang
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Shengwei
authors.initials: S
authors.lastname: Zhuang
mesh_terms: D013856:Acidithiobacillus thiooxidans / Q000378:metabolism; D007854:Lead / Q000032:analysis / Q000378:metabolism*; D019216:Metals, Heavy / Q000378:metabolism*; D008906:Mining; D010084:Oxidation-Reduction; D012492:Salts / Q000378:metabolism*; D012965:Sodium Chloride / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D015032:Zinc / Q000032:analysis / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D012492:Salts; D014874:Water Pollutants, Chemical; C017082:brine; D007854:Lead; D012965:Sodium Chloride; D015032:Zinc
keywords: Bioleaching; Brine leaching; Heavy metal; Lead; Mine tailings; Transformation