Thermodynamic Modelling of Geo-Biometallurgical Oxidation of Sulfide Ores

2015 ◽  
Vol 1130 ◽  
pp. 50-54
Author(s):  
Sergey S. Gudkov ◽  
Yuri Ye. Yemelianov ◽  
Luidmila Ye. Shketova ◽  
Natalia V. Kopylova ◽  
Tatiana Yu. Afonina
Keyword(s):  
Solid Phase ◽  
Reaction Pathway ◽  
Sulfide Oxidation ◽  
Metastable Equilibrium ◽  
Sulfide Ores ◽  
Bacterial Oxidation ◽  
Sulfide Ore ◽  
Sulfides Oxidation ◽  
Alkaline Conditions ◽  
Gold Bearing

Heap bioleaching of sulfide ores (geotechnology) simulates naturally occurring processes when sulfides convert to oxides. This process is environmentally-friendly. Gold-bearing sulfide ore from a Russian deposit was studied. The samples were composed of quartz (38-48%), feldspars (22-24%) and micaceous minerals (18-21%). Carbonates occurred as ankerite, calcite, dolomite and siderite. The host minerals were pyrite (2.2-2.3%) and arsenopyrite (1.2-1/7%). The grade of gold was 1.6-2.0 g/t. Russian software package Selector was used to develop the model. Thermodynamics of the reaction pathway for the conversion of the gold-bearing sulfide ore in H2SO4 environment with and without using bacteria was calculated. Phases and their components which are able to form in these given conditions were selected during modeling. Modeling of irreversible evolution of the rocks caused by bacteria was carried out in the three reservoir system. They are interconnected by the flows of three movable phases: gases, solid phase and liquid phase. In this case, the composition of the solutions which were obtained under steady state conditions without bacteria and metastable equilibrium using bacteria can be compared. Bacterial oxidation occurs under acidic conditions. Oxidation without using bacteria occurs under more alkaline conditions. Bacteria increase the rate of sulfides oxidation and retard the formation of mixed-layer aluminum silicates (illites, montmorillomonites) and carbonates (magnesian calcite). It was found that bacteria have the potential to achieve the required destruction of sulfides in favorable environment. Bacteria make the rate of sulfide oxidation higher. In the presence of bacteria, the rate of aluminosilicates oxidation is slower compared to the conditions without using bacteria. Mineralogical analyses of the leach products confirmed this. Results show that thermodynamic approach can be successfully used for the modeling of bacterial-oxidation circuits and geology of the rocks and ores.

The mechanism of formation of 2,7-dimethyl-2,6-octadiene in the synthesis of 3-methylene-7-methyl-1,6-octadiene

1983 ◽  
Vol 48 (7) ◽  
pp. 1864-1866
Author(s):  
Jan Bartoň ◽  
Ivan Kmínek
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Alkali Metal ◽  
Chromatographic Analysis ◽  
Solid Phase ◽  
Reaction Pathway ◽  
Mechanism Of Formation ◽  
Gas Chromatographic Analysis ◽  
C Nmr ◽  
Visual Observations

2,7-Dimethyl-2,6-octadiene is formed in the catalytic solution for the dimerization of 2-methyl-1,3-butadiene to β-myrcene (3-methylene-7-methyl-1,6-octadiene), as revealed by mass spectrometry and 13C NMR spectroscopy. Visual observations together with the results of gas chromatographic analysis of the catalytic solution suggest that the formation of 2,7-dimethyl-2,6-octadiene is associated with the transition of the alkali metal (sodium) from the solid phase into the solution. A reaction pathway is suggested accounting for the formation of 2,7-dimethyl-2,6-octadiene in the system.

Electrochemical Dissolution of Goethite by Abrasive Stripping Voltammetry

1995 ◽  
Vol 60 (6) ◽  
pp. 950-959 ◽  
Author(s):  
Tomáš Grygar ◽  
Jan Šubrt ◽  
Jaroslav Boháček
Keyword(s):  
Solid Phase ◽  
Reaction Pathway ◽  
Stripping Voltammetry ◽  
Electrode Reaction ◽  
Reductive Dissolution ◽  
Quantitative Characterization ◽  
Acid Media ◽  
Qualitative And Quantitative ◽  
Spectroscopic Examination

Abrasive stripping voltammetry was applied to the investigation of the reductive dissolution of some iron(III) oxides and hydroxy-oxides, particularly goethite (α-FeOOH), in acid media. The electrode reaction directly involves the solid phase, and the reaction pathway depends on the phase composition and particle shape. This can be used for a qualitative and quantitative characterization of goethite. The results of a quantitative analysis of a mixture of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH) are compared with those of IR and Moessbauer spectroscopic examination. The effects of the particle appearance (shape, crystal intergrowth) on the results of the voltammetric and chronoamperometric measurements are discussed.

Epithermal gold-bearing sulfide ore deposit Tulallar: Structure, structural geology and mineralization patterns

2021 ◽  
pp. 53-60
Author(s):  
Sh. F. Abdullaeva ◽  
V. M. Baba-zade ◽  
N. A. Imamverdiev ◽  
N. N. Ismailova
Keyword(s):  
Structural Geology ◽  
Epithermal Gold ◽  
Ore Deposit ◽  
Sulfide Ore ◽  
Gold Bearing

Role of geochemical barriers in forming sulfide ores in various geological environments

2021 ◽  
pp. 63-73
Author(s):  
IRINA GABLINA
Keyword(s):  
Sulfide Ores ◽  
Atlantic Region ◽  
Geochemical Barriers ◽  
Sulfide Ore ◽  
Cupriferous Sandstone ◽  
Central Atlantic ◽  
Ore Types ◽  
Long Term Studies

Based on long-term studies of cupriferous sandstone and shale deposits, as well as deepsea sulfide ores, various types of geochemical barriers where sulfides form are shown. Cupriferous sandstones and shales form as metals precipitate from redbed reservoir waters on H2S geochemical barrier. Syngenetic and epigenetic barrier types are identified. Oceanic sulfide ores from the Central Atlantic region were studied; as a result, a new hydrothermal-metasomatic sediment-hosted mineralization type was found, along with previously known sulfide ore types (massive ores on the seafloor and stockwork ores in substrate rocks). Geochemical seafloor sulfide formation environments and those in biogenic carbonate bottom sediments are examined.

Effect of antimonate on the bacterial oxidation of sulfide minerals extracted from persistent gold-bearing ores

Metallurgist ◽  
2011 ◽  
Vol 55 (7-8) ◽  
pp. 526-533
Author(s):  
A. V. Kanarskii ◽  
L. N. Krylova ◽  
E. V. Adamov
Keyword(s):  
Sulfide Minerals ◽  
Bacterial Oxidation ◽  
Gold Bearing

scholarly journals Recovery of gangliosides from aqueous solutions on styrene-divinylbenzene copolymer columns

2002 ◽  
Vol 43 (8) ◽  
pp. 1335-1340 ◽  
Author(s):  
Iuliana Popa ◽  
Cristina Vlad ◽  
Jacques Bodennec ◽  
Jacques Portoukalian
Keyword(s):  
Aqueous Solutions ◽  
Silica Gel ◽  
Salt Concentration ◽  
High Stability ◽  
Solid Phase ◽  
General Procedure ◽  
Optimal Conditions ◽  
Alkaline Conditions ◽  
Styrene Divinylbenzene ◽  
Multiple Cycles

An investigation was made using a styrene-divinylbenzene copolymer as a solid phase sorbent to recover gangliosides from aqueous solutions. A comparison with octadecyl-bonded (C18) silica gel showed that the general procedure used to purify gangliosides on C18 silica gel could be used with the copolymer. The yield of gangliosides depended on various parameters such as the composition of the conditioning solution, the salt concentration of the loading solution, and the amount of applied gangliosides per gram of copolymer. In optimal conditions, the recovery of gangliosides and other lipids present in the upper phases of partition was higher than 95%. Using radiolabeled gangliosides, it was found that gangliosides present in serum-containing medium could also be quantitatively recovered on copolymer, provided the medium was diluted with an equal volume of methanol prior to its application onto the column.The major advantage of the copolymer is its high stability in acidic or alkaline conditions that allows multiple cycles of cleaning and reconditioning of the sorbent without alteration of its chromatographic properties.

scholarly journals Inhibition of microbiological sulfide oxidation by methanethiol and dimethyl polysulfides at natron-alkaline conditions

2009 ◽  
Vol 83 (3) ◽  
pp. 579-587 ◽  
Author(s):  
Pim L. F. van den Bosch ◽  
Marco de Graaff ◽  
Marc Fortuny-Picornell ◽  
Robin C. van Leerdam ◽  
Albert J. H. Janssen
Keyword(s):  
Sulfide Oxidation ◽  
Alkaline Conditions

Biooxidation of gold-bearing sulfide ore and subsequent biological treatment of cyanidation residues

2016 ◽  
Vol 52 (4) ◽  
pp. 397-405 ◽  
Author(s):  
A. T. Kanayev ◽  
A. G. Bulaev ◽  
G. V. Semenchenko ◽  
Z. K. Kanayeva ◽  
A. A. Shilmanova
Keyword(s):  
Biological Treatment ◽  
Sulfide Ore ◽  
Gold Bearing

Microbial Population of Industrial Biooxidation Reactors

2017 ◽  
Vol 262 ◽  
pp. 48-52 ◽  
Author(s):  
Aleksander Bulaev ◽  
Aleksandr Belyi ◽  
Anna Panyushkina ◽  
Natalia Solopova ◽  
Tatyana Pivovarova
Keyword(s):  
16S Rrna ◽  
Microbial Population ◽  
Acid Soils ◽  
Rrna Gene ◽  
Acidithiobacillus Thiooxidans ◽  
Nutrient Media ◽  
Molecular Biological Analysis ◽  
Sulfide Ore ◽  
Ferroplasma Acidarmanus ◽  
Gold Bearing

Microbial population performing biooxidation of flotation concentrate of gold bearing sulfide ore containing pyrite, arsenopyrite, and pyrrhotite was studied using cultural and molecular biological (metagenomics sequencing of V3-V4 fragments of 16S rRNA gene) approaches. The biooxidation of the concentrate was conducted at temperatures from 38 to 42°C. Strains of Acidithiobacillus thiooxidans, Acidiphilium multivorum, Leptospirillum ferriphilum, Sulfobacillus thermotolerans, Ferroplasma acidarmanus, and Ferroplasma acidiphilum were isolated from the samples of the pulp from biooxidation reactors. It was shown that optimum temperatures of isolated strains were from 38 to 40°C. Metagenomic analysis demonstrated predominance of the genera Acidiferrobacter, Acidithiobacillus, Acidiphilum, Leptospirillum, and Ferroplasma. According to results of molecular biological analysis, share of the genus Acidithiobacillus was of 0 to 25%, share of the genus Acidiferrobacter was of 7 to 56%, share of the genus Acidiphilum was of 0.03 to 36%, share of the genus Leptospirillum was of 0.7 to 7%, whereas share of the archaea of the genus Ferroplasma was of 33 to 94%. Thus, it was shown that representatives of the genus Ferroplasma can play significant role in bioleach process. Representatives of the genus Acidiferrobacter were previously detected in acid mine drainages, acid soils as well as in bioleach heaps and reactors, whereas data on predominance of the genus in tank bioleach processes have not been presented in the literature. In the present study, strains of the genus Acidiferrobacter were not isolated despite application of the nutrient media recommended for Acidiferrobacter and their properties were not studied. Nevertheless, results of the present study suggest that representatives of the genus Acidiferrobacter have a great impact on industrial bioleach processes.

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