The Mechanism of Bacterial Action in the Leaching of Pyrite by Thiobacillus ferrooxidans. An Electrochemical Study

1999 ◽  
Vol 146 (8) ◽  
pp. 2906-2912 ◽  
Author(s):  
P. R. Holmes ◽  
T. A. Fowler ◽  
F. K. Crundwell
1978 ◽  
Vol 24 (7) ◽  
pp. 888-891 ◽  
Author(s):  
Arpad E. Torma

The bacterial oxidation of a naturally occurring gallium-bearing chalcopyrite concentrate and a pure synthetic gallium (III) sulfide has been investigated at pH 1.8 and 35 °C, using an active culture of Thiobacillus ferrooxidans. This oxidation process may proceed by direct or by indirect bacterial action. The highest dissolved gallium and copper concentrations were about 2.2 and 40.2 g/ℓ respectively. The order of the specific rate of oxygen uptake by T. ferrooxidans is approximately CuFeS2[Formula: see text] gallium-bearing CuFeS2 > FeS2 > CuS > Cu2S > Ga2S3.


Author(s):  
V.K. Berry

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.


2019 ◽  
Vol 43 (48) ◽  
pp. 19379-19396 ◽  
Author(s):  
Pooja S. Singh ◽  
Purav M. Badani ◽  
Rajesh M. Kamble

An opto-electrochemical study of D–A based indolo-quinoxaline amine derivatives was performed by varying the strength of the amine substituent.


2013 ◽  
Vol 16 (2) ◽  
pp. 130-141
Author(s):  
Ondrej Zitka ◽  
Sona Krizkova ◽  
Sylvie Skalickova ◽  
Pavel Kopel ◽  
Petr Babula ◽  
...  

2021 ◽  
Vol 125 (7) ◽  
pp. 1436-1446
Author(s):  
Inna Popivker ◽  
Dan Meyerstein ◽  
Dalia Gitin ◽  
Elad N. Avraham ◽  
Eric Maimon ◽  
...  

Author(s):  
Xinyue Li ◽  
Marco Fortunato ◽  
Anna Maria Cardinale ◽  
Angelina Sarapulova ◽  
Christian Njel ◽  
...  

AbstractNickel aluminum layered double hydroxide (NiAl LDH) with nitrate in its interlayer is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the performance of the material is investigated in 1 M LiPF6 in EC/DMC vs. Li. The NiAl LDH electrode based on sodium alginate (SA) binder shows a high initial discharge specific capacity of 2586 mAh g−1 at 0.05 A g−1 and good stability in the potential range of 0.01–3.0 V vs. Li+/Li, which is better than what obtained with a polyvinylidene difluoride (PVDF)-based electrode. The NiAl LDH electrode with SA binder shows, after 400 cycles at 0.5 A g−1, a cycling retention of 42.2% with a capacity of 697 mAh g−1 and at a high current density of 1.0 A g−1 shows a retention of 27.6% with a capacity of 388 mAh g−1 over 1400 cycles. In the same conditions, the PVDF-based electrode retains only 15.6% with a capacity of 182 mAh g−1 and 8.5% with a capacity of 121 mAh g−1, respectively. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. Graphical abstract The as-prepared NiAl-NO3−-LDH with the rhombohedral R-3 m space group is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the material’s performance is investigated in 1 M LiPF6 in EC/DMC vs. Li. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. This work highlights the possibility of the direct application of NiAl LDH materials as negative electrodes for LIBs.


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