New understanding of the reduction mechanism of pyrolusite in the Acidithiobacillus ferrooxidans bio-leaching system

doi:10.1016/j.electacta.2018.12.031

	New understanding of the reduction mechanism of pyrolusite in the Acidithiobacillus ferrooxidans bio-leaching system
	Kang, Jin-xing 1; Feng, Ya-li 1; Li, Hao-ran 2; Du, Zhu-wei 2; Deng, Xiang-yi 1; Wang, Hong-jun 1
刊名	ELECTROCHIMICA ACTA
	2019-02-20
卷号	297 页码:443-451
关键词	Acidithiobacillus ferrooxidans Manganese dioxide Electrochemistry Electron transfer Carrier density
ISSN号	0013-4686
DOI	10.1016/j.electacta.2018.12.031
英文摘要	The reductive dissolution of pyrolusite in simulated Acidithiobacillus ferrooxidans bio-leaching medium was investigated. This study was performed in three stages. First, the advantageous electrochemical test conditions, parallel to the optimal bio-leaching conditions and adopting the Mn reduction rate, were determined by imitated electrolysis. The facilitation of A. ferrooxidans on MnO2 reduction is sensitive to pH and Fe(III) concentration. Second, electrochemical tests revealed that the reductive dissolution of manganese dioxide incorporated two single electron and proton steps-the first exchange of MnO2 to MnO center dot OH, and then conversion to Mn(OH)(2) for diffusion. The results of transient and steady electrochemical measurements indicated that the first electron-transfer significantly affects the rate controlling step of Mn-leaching in control(9K) medium, while using A. ferrooxidans and Fe(III) in the solution tends to enable the leaching rate to be controlled by the latter electron transfer step. Third, the analysis of semiconductor and carrier properties of passive films of pyrolusite formed in the different solutions, illustrated that the reductive dissolution of manganese dioxide tends to depend on the movement of the holes. The first electron preferentially reacts with the shallow energy level of the O-vacancy to form MnO2-, which then absorbs H+ to become MnO center dot OH. The second electron participates in the transformation of MnO center dot OH to (MnOH)(OH) and then to Mn(OH)(2). A. ferrooxidans increases the carrier densities of the passivating film accelerating electron and proton transfer and Fe(III) primarily influences the shallow donor density of oxygen during the first electron-exchange. Additionally, the synergistic effect of A. ferrooxidans and Fe(III) on manganese dioxide ore reductive leaching is confirmed. (C) 2018 Elsevier Ltd. All rights reserved.
资助项目	China Ocean Biological Resources Development Program[DY135-B2-15] ; Major Science and Technology Program for Water Pollution Control and Treatment[2015ZX07205-003] ; National Natural Science Foundation of China[21176026] ; National Natural Science Foundation of China[21176242]
WOS关键词	PART 1 ; MANGANESE ; KINETICS ; MNO2 ; ORES ; DISSOLUTION ; ELECTRODES ; CARBON ; PYRITE
WOS研究方向	Electrochemistry
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000455642500050
资助机构	China Ocean Biological Resources Development Program ; Major Science and Technology Program for Water Pollution Control and Treatment ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.ipe.ac.cn/handle/122111/27803]
专题	中国科学院过程工程研究所
通讯作者	Feng, Ya-li
作者单位	1.Univ Sci & Technol, Sch Civil & Resource Engn, Beijing 100083, Peoples R China 2.Chinese Acad Sci, Inst Proc Engn, State Key Lab Biochem Engn, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Kang, Jin-xing,Feng, Ya-li,Li, Hao-ran,et al. New understanding of the reduction mechanism of pyrolusite in the Acidithiobacillus ferrooxidans bio-leaching system[J]. ELECTROCHIMICA ACTA,2019,297:443-451.
APA	Kang, Jin-xing,Feng, Ya-li,Li, Hao-ran,Du, Zhu-wei,Deng, Xiang-yi,&Wang, Hong-jun.(2019).New understanding of the reduction mechanism of pyrolusite in the Acidithiobacillus ferrooxidans bio-leaching system.ELECTROCHIMICA ACTA,297,443-451.
MLA	Kang, Jin-xing,et al."New understanding of the reduction mechanism of pyrolusite in the Acidithiobacillus ferrooxidans bio-leaching system".ELECTROCHIMICA ACTA 297(2019):443-451.