Cambridge,UK:Cambridge University Press,2003,383页,ISBN 0-521-81428-6。黄亚生(Huang Yasheng)所著 Selling China 是剑桥当代中国系列丛书的一本。中国目前是全世界最知名的跨国直接投资目的地,在20世纪90年代长期居于全世界吸收 ...Cambridge,UK:Cambridge University Press,2003,383页,ISBN 0-521-81428-6。黄亚生(Huang Yasheng)所著 Selling China 是剑桥当代中国系列丛书的一本。中国目前是全世界最知名的跨国直接投资目的地,在20世纪90年代长期居于全世界吸收 FDI(foreign direct investment,FDI)的第二大国和发展中国家第一大国,2003年更超过美国成为吸收 FDI 第一大国,所以研究当代中国的经济,不能不涉及展开更多
The electrochemical oxidation behavior of pyrite in bioleaching system of Acidthiobacillusferrooxidans was investigated by cyclic voltammetry （CV）, polarization curve and electrochemical impedance spectroscopy （EIS...The electrochemical oxidation behavior of pyrite in bioleaching system of Acidthiobacillusferrooxidans was investigated by cyclic voltammetry （CV）, polarization curve and electrochemical impedance spectroscopy （EIS）. The results show that in the presence or absence of A. ferrooxidans, the oxidation reaction of pyrite is divided into two steps： the first reaction step involves the oxidation of pyrite to S, and the second reaction step is the oxidation of S to SO4^2-. The oxidation mechanism of pyrite is not changed in the presence of A. ferrooxidans, but the oxidation rate of pyrite is accelerated. With the extension of reaction time of A. ferrooxidan with pyrite, the polarization current density of pyrite increases and the breakdown potential at which the passive film dissolves decreases. The impedance in the presence ofA. ferrooxidans is obviously lower than that in the absence of A. ferrooxidans, further indicating that microorganism accelerates the corrosion process of pyrite.展开更多
Electrochemical measurements were carried out to elucidate decomposition mechanism of pentlandite using modified powder microelectrode with Acidithiobacillus ferrooxidans attached or without on the mineral powder surf...Electrochemical measurements were carried out to elucidate decomposition mechanism of pentlandite using modified powder microelectrode with Acidithiobacillus ferrooxidans attached or without on the mineral powder surface.Cyclic voltammetry（CV） results show that at a low potential of about-0.2 V（vs SCE）,the pentlandite was transformed to an intermediated phase like Fe4.5-yNi4.5-xS8-z when Fe and Ni ions were evacuated from mineral lattice;when the potential was changed from-0.2 V to 0.2 V,the unstable violarite（Fe3Ni3S4） and FeNi2S4 were formed which was accompanied by element sulfur formed on the mineral surface;when the potential increased over 0.2 V,the unstable intermediated phase decomposed entirely;at a higher potential of 0.7 V,the evacuated ferrous ion was oxidized to ferric ion.The presence of Acidithiobacillus ferrooxidans made the oxidation peak current increase with initial peak potential negatively moving,and the bacteria also contributed to the sulfur removing from mineral surface,which was demonstrated by the reduction characteristic at potential ranging from-0.75 to-0.5 V.Leaching experiments and electrochemical results show that the solution acidity increasing when pH2 may impede the oxidation process slightly.展开更多
文摘Cambridge,UK:Cambridge University Press,2003,383页,ISBN 0-521-81428-6。黄亚生(Huang Yasheng)所著 Selling China 是剑桥当代中国系列丛书的一本。中国目前是全世界最知名的跨国直接投资目的地,在20世纪90年代长期居于全世界吸收 FDI(foreign direct investment,FDI)的第二大国和发展中国家第一大国,2003年更超过美国成为吸收 FDI 第一大国,所以研究当代中国的经济,不能不涉及
基金Project (2010CB630903) supported by the National Basic Research Program of China
文摘The electrochemical oxidation behavior of pyrite in bioleaching system of Acidthiobacillusferrooxidans was investigated by cyclic voltammetry （CV）, polarization curve and electrochemical impedance spectroscopy （EIS）. The results show that in the presence or absence of A. ferrooxidans, the oxidation reaction of pyrite is divided into two steps： the first reaction step involves the oxidation of pyrite to S, and the second reaction step is the oxidation of S to SO4^2-. The oxidation mechanism of pyrite is not changed in the presence of A. ferrooxidans, but the oxidation rate of pyrite is accelerated. With the extension of reaction time of A. ferrooxidan with pyrite, the polarization current density of pyrite increases and the breakdown potential at which the passive film dissolves decreases. The impedance in the presence ofA. ferrooxidans is obviously lower than that in the absence of A. ferrooxidans, further indicating that microorganism accelerates the corrosion process of pyrite.
基金Project(20876014) supported by the National Natural Science Foundation of China
文摘Electrochemical measurements were carried out to elucidate decomposition mechanism of pentlandite using modified powder microelectrode with Acidithiobacillus ferrooxidans attached or without on the mineral powder surface.Cyclic voltammetry（CV） results show that at a low potential of about-0.2 V（vs SCE）,the pentlandite was transformed to an intermediated phase like Fe4.5-yNi4.5-xS8-z when Fe and Ni ions were evacuated from mineral lattice;when the potential was changed from-0.2 V to 0.2 V,the unstable violarite（Fe3Ni3S4） and FeNi2S4 were formed which was accompanied by element sulfur formed on the mineral surface;when the potential increased over 0.2 V,the unstable intermediated phase decomposed entirely;at a higher potential of 0.7 V,the evacuated ferrous ion was oxidized to ferric ion.The presence of Acidithiobacillus ferrooxidans made the oxidation peak current increase with initial peak potential negatively moving,and the bacteria also contributed to the sulfur removing from mineral surface,which was demonstrated by the reduction characteristic at potential ranging from-0.75 to-0.5 V.Leaching experiments and electrochemical results show that the solution acidity increasing when pH2 may impede the oxidation process slightly.
