Adaptation of Thiobacillus ferrooxidans to nickel ion and bacterial oxidation of nickel sulfide

1995 ◽  
Vol 17 (2) ◽  
pp. 229-232 ◽  
Author(s):  
Takami Kai} ◽  
Makoto Nishi ◽  
Takeshige Takahashi
Keyword(s):  
Nickel Sulfide ◽  
Thiobacillus Ferrooxidans ◽  
Nickel Ion ◽  
Bacterial Oxidation

Leaching of Zinc Sulfide by Thiobacillus ferrooxidans: Bacterial Oxidation of the Sulfur Product Layer Increases the Rate of Zinc Sulfide Dissolution at High Concentrations of Ferrous Ions

1999 ◽  
Vol 65 (12) ◽  
pp. 5285-5292 ◽  
Author(s):  
T. A. Fowler ◽  
F. K. Crundwell
Keyword(s):  
Zinc Sulfide ◽  
Thiobacillus Ferrooxidans ◽  
Particle Surface ◽  
Product Layer ◽  
Ferrous Ions ◽  
Bacterial Oxidation ◽  
Rate Of Dissolution ◽  
Shrinking Core ◽  
Leaching Experiments ◽  
High Concentrations

ABSTRACT This paper reports the results of leaching experiments conducted with and without Thiobacillus ferrooxidans at the same conditions in solution. The extent of leaching of ZnS with bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, while no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T. ferrooxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions.

Optimization of Bacterial Oxidation Process Parameters for Selective Leaching of Nickel by Thiobacillus Ferrooxidans

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Ravindra Pogaku ◽  
Bharathi Kodali
Keyword(s):  
Particle Size ◽  
Process Parameters ◽  
Thiobacillus Ferrooxidans ◽  
Oxidation Process ◽  
Inoculum Size ◽  
Pulp Density ◽  
Transfer Resistance ◽  
Bacterial Oxidation ◽  
Flotation Concentrate ◽  
Copper Flotation

Nickel bioleaching from copper flotation concentrate assumes greater significance because of its value and not many studies are carried out in these lines. Hence, nickel leaching was attempted and several process parameters of bacterial oxidation for copper flotation concentrate were examined for optimization. The parameters considered for shake flask leaching experiments were temperature, pulp density, particle size, agitation, residence time and inoculum size. The effect of variable proportions of each parameter on nickel leachability was studied. Optimum values of pulp density (10%) and agitation (140 rpm) played an important role in controlling the mass transfer resistance during leaching process. Increase in temperature from 27oC to 30oC has accelerated the bacterial oxidation process while initial concentration of inoculum (1-10%) has not shown considerable variation in nickel leachability. A particle size of ±60#size was found to be essential for bacterial attack. Maintenance of optimum conditions of leaching has yielded considerable nickel recovery (55%) compared to low recovery under unoptimal conditions.

Oxidation of gallium sulfides by Thiobacillus ferrooxidans

1978 ◽  
Vol 24 (7) ◽  
pp. 888-891 ◽  
Author(s):  
Arpad E. Torma
Keyword(s):  
Oxygen Uptake ◽  
Thiobacillus Ferrooxidans ◽  
Oxidation Process ◽  
Specific Rate ◽  
Bacterial Oxidation ◽  
Naturally Occurring ◽  
Bacterial Action ◽  
Chalcopyrite Concentrate

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.

Oxidation of metal sulfides by Thiobacillus ferrooxidans grown on different substrates

1974 ◽  
Vol 20 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Marvin Silver ◽  
Arpad E. Torma
Keyword(s):  
Lead Sulfide ◽  
Ferrous Sulfate ◽  
Nickel Sulfide ◽  
Thiobacillus Ferrooxidans ◽  
Cell Types ◽  
Metal Sulfides ◽  
Sulfide Ore ◽  
Sulfate Lead ◽  
Chalcopyrite Ore ◽  
Sulfide Concentrate

Thiobacillus ferrooxidans, grown on either ferrous sulfate, lead sulfide concentrate, or chalcopyrite concentrate demonstrated oxygen uptake and CO2 fixation in the presence of ferrous sulfate, chalcopyrite ore, pyrite ore, and red antimony trisulfide. Lead suifide-grown cells could oxidize lead sulfide ore and galena, using the energy obtained for CO2 fixation. All three cell types could oxidize nickel sulfide, but could not fix CO2 in the presence of this substrate. The solubilization of metals from the substrates and the crystallographic changes in the insoluble residues are reported.

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

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.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Optimizing electron density of nickel sulfide electrocatalysts through sulfur vacancy engineering for alkaline hydrogen evolution

2020 ◽  
Vol 8 (35) ◽  
pp. 18207-18214
Author(s):  
Dongbo Jia ◽  
Lili Han ◽  
Ying Li ◽  
Wenjun He ◽  
Caichi Liu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Electron Density ◽  
Rational Design ◽  
Nickel Sulfide ◽  
Catalytic Performance ◽  
Sulfide Catalysts ◽  
Sulfur Vacancy

A novel, rational design for porous S-vacancy nickel sulfide catalysts with remarkable catalytic performance for alkaline HER.

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