Eco-friendly and rapid extraction of gold by in-situ catalytic oxidation with N-bromosuccinimide
Xiang Liu,
Yongliang Wang,
Li Xiao,
Licheng Ma,
Peiwei Han,
Shufeng Ye
Affiliations
Xiang Liu
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 1 North 2nd Street, Zhongguancun, Haidian District, Beijing, 100190, PR China; School of Chemical Engineering, University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, PR China
Yongliang Wang
Beijing Research Institute of Chemical Engineering and Metallurgy, CNNC, Beijing, 101149, China; Corresponding author.
Li Xiao
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 1 North 2nd Street, Zhongguancun, Haidian District, Beijing, 100190, PR China; School of Chemical Engineering, University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, PR China
Licheng Ma
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 1 North 2nd Street, Zhongguancun, Haidian District, Beijing, 100190, PR China; Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, PR China
Peiwei Han
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 1 North 2nd Street, Zhongguancun, Haidian District, Beijing, 100190, PR China; Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, PR China
Shufeng Ye
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 1 North 2nd Street, Zhongguancun, Haidian District, Beijing, 100190, PR China; Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, PR China; Corresponding author.
Gold is a valued, critical element whose chemical activation or extraction is challenging. Non-cyanide extraction of gold is now the focus, and N-bromosuccinimide(NBS) is attracting attention. Herein, new insights into the possible mechanism are deeply revealed through comprehensive analysis and detection of the reaction by using elementary gold and gold bearing ore. Experiments on gold foil indicate that Au can be activated in NBS solution to perform a satisfactory dissolution. Application of NBS in gold extraction from ore show a high yield of 86.24% under optimal conditions of NBS dosage 0.05 M, liquid-solid ratio 4:1, stirring speed 400 rpm, pH 8, 25 °C and leaching for 20 h, while yields of other coexisting metals are nearly negligible. The process leads to direct, efficient, one-pot conversion of gold, into simple water-soluble salts. Characterizations show that the framework of NBS are not destroyed, only bromine separates from the framework. The oxidation of neutral gold atom to trivalent Au(III) occurs in a mild, clean and room-temperature chemistry, which converts gold to [AuBr4]-, and the framework to succinimide. The active bromine and radical Br (Br•) generated from in-situ autocatalysis of NBS are responsible for this. The systematic results herald a green procedure for preparation of gold derivatives and gold extraction industry.
