Bioleaching of a Rich-In-Carbonates Copper Ore at Alkaline pH

A rich-in- carbonates copper ore was subjected to bioleaching under alkaline pH conditions by means of different microorganisms or their metabolites. The ore contained 1.40% copper, 1.94% sulphur, 3.25% iron and 20.3% carbonates, and had a pH of 8.6 and a highly positive net neutralization potential (325 kg CaCO3/t). Copper was present mainly as different sulphide minerals (bornite, covellite, chalcopyrite). The leaching was carried out by means of the shake-flask technique at 32 oC using finely ground (minus 100 μm) ore. The following microorganisms were used to leach the sample: ammonifying bacteria (related to the genera Bacillus, Acinetocater and Vibrio); heterotrophic bacteria (Acetobacter and Pseudomonas) and fungi (Asperillus niger and Penicillium chrysogenum) producing citric acid; heterotrophic bacteria (Micrococcus, Alcaligenes and Bacillus) producing amino acids (mainly alanine); basophilic chemolithotrophic bacteria (Thiobacillus thioparus, Hallothiobacillus neapolitanus, Starkeya novella; ”silicate bacteria” (Bacillus circulans) producing organic acids and exopolysaccharides; bacteria possessing urease enzymatic activity (Corynebacterium). The best results were achieved by means of a mixed culture of urease-possessing bacteria, which under certain conditions was able to solubilize 64.4% of the copper within 30 days of leaching.

Download Full-text

Bioflotation of a Black Shale Copper Ore

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.20-21.358 ◽

2007 ◽

Vol 20-21 ◽

pp. 358-361 ◽

Cited By ~ 1

Author(s):

Irena Spasova ◽

Marina Nicolova ◽

Stoyan N. Groudev

Keyword(s):

Black Shale ◽

Black Shales ◽

Copper Recovery ◽

Two Stage ◽

Copper Ore ◽

Microbial Pretreatment ◽

Chemolithotrophic Bacteria ◽

Silicate Bacteria ◽

Reducing Bacteria ◽

Positive Effect

A sample of black shale fraction of copper ore from the Lubin deposit, Poland, was subjected to pretreatment by different microorganisms to improve the copper recovery during the subsequent flotation. Chemolithotrophic bacteria grown on So and S2O3 2- were used to depress pyrite before flotation by means of ethyl xantate as collector. Sulphate-reducing bacteria were used to perform a prior sulphidization of the black shales before flotation by means of the same collector. Two-stage flotation experiments were carried out in which initially the gangue minerals of the ore were depressed by means of “silicate” bacteria and then, during the flotation of the non-floated product from the first stage, the pyrite was depressed by means of pretreatment with So- grown chemolithotrophs. In all these cases the microbial pretreatment had positive effect on the copper recovery.

Download Full-text

Cupriavidus necator H16 Uses Flavocytochrome c Sulfide Dehydrogenase To Oxidize Self-Produced and Added Sulfide

Applied and Environmental Microbiology ◽

10.1128/aem.01610-17 ◽

2017 ◽

Vol 83 (22) ◽

Cited By ~ 5

Author(s):

Chuanjuan Lü ◽

Yongzhen Xia ◽

Daixi Liu ◽

Rui Zhao ◽

Rui Gao ◽

...

Keyword(s):

Gas Phase ◽

Heterotrophic Bacteria ◽

Sulfide Oxidation ◽

Cupriavidus Necator ◽

Content Type ◽

Sulfide:Quinone Oxidoreductase ◽

Transport Chain ◽

Genes Encoding ◽

Cupriavidus Necator H16 ◽

Chemolithotrophic Bacteria

ABSTRACT Production of sulfide (H2S, HS−, and S2−) by heterotrophic bacteria during aerobic growth is a common phenomenon. Some bacteria with sulfide:quinone oxidoreductase (SQR) and persulfide dioxygenase (PDO) can oxidize self-produced sulfide to sulfite and thiosulfate, but other bacteria without these enzymes release sulfide into the medium, from which H2S can volatilize into the gas phase. Here, we report that Cupriavidus necator H16, with the fccA and fccB genes encoding flavocytochrome c sulfide dehydrogenases (FCSDs), also oxidized self-produced H2S. A mutant in which fccA and fccB were deleted accumulated and released H2S. When fccA and fccB were expressed in Pseudomonas aeruginosa strain Pa3K with deletions of its sqr and pdo genes, the recombinant rapidly oxidized sulfide to sulfane sulfur. When PDO was also cloned into the recombinant, the recombinant with both FCSD and PDO oxidized sulfide to sulfite and thiosulfate. Thus, the proposed pathway is similar to the pathway catalyzed by SQR and PDO, in which FCSD oxidizes sulfide to polysulfide, polysulfide spontaneously reacts with reduced glutathione (GSH) to produce glutathione persulfide (GSSH), and PDO oxidizes GSSH to sulfite, which chemically reacts with polysulfide to produce thiosulfate. About 20.6% of sequenced bacterial genomes contain SQR, and only 3.9% contain FCSD. This is not a surprise, since SQR is more efficient in conserving energy because it passes electrons from sulfide oxidation into the electron transport chain at the quinone level, while FCSD passes electrons to cytochrome c. The transport of electrons from the latter to O2 conserves less energy. FCSDs are grouped into three subgroups, well conserved at the taxonomic level. Thus, our data show the diversity in sulfide oxidation by heterotrophic bacteria. IMPORTANCE Heterotrophic bacteria with SQR and PDO can oxidize self-produced sulfide and do not release H2S into the gas phase. C. necator H16 has FCSD but not SQR, and it does not release H2S. We confirmed that the bacterium used FCSD for the oxidation of self-produced sulfide. The bacterium also oxidized added sulfide. The common presence of SQRs, FCSDs, and PDOs in heterotrophic bacteria suggests the significant role of heterotrophic bacteria in sulfide oxidation, participating in sulfur biogeochemical cycling. Further, FCSDs have been identified in anaerobic photosynthetic bacteria and chemolithotrophic bacteria, but their physiological roles are unknown. We showed that heterotrophic bacteria use FCSDs to oxidize self-produced sulfide and extraneous sulfide, and they may be used for H2S bioremediation.

Download Full-text

Treatment of bitumen post oxidative effluents by sulfate radicals based advanced oxidation processes (S-AOPs) under alkaline pH conditions

Journal of Cleaner Production ◽

10.1016/j.jclepro.2018.05.207 ◽

2018 ◽

Vol 195 ◽

pp. 374-384 ◽

Cited By ~ 76

Author(s):

André Fernandes ◽

Patrycja Makoś ◽

Grzegorz Boczkaj

Keyword(s):

Advanced Oxidation Processes ◽

Advanced Oxidation ◽

Alkaline Ph ◽

Sulfate Radicals ◽

Oxidation Processes ◽

Ph Conditions

Download Full-text

Dynamic Regulation of the 7TM Receptor Bacteriorhodopsin Function under Alkaline pH Conditions

Biophysical Journal ◽

10.1016/j.bpj.2015.11.866 ◽

2016 ◽

Vol 110 (3) ◽

pp. 154a

Author(s):

Xiaoyan Ding ◽

Haolin Cui ◽

Honglei Wang ◽

Yujiao Gao ◽

Bo Peng ◽

...

Keyword(s):

Alkaline Ph ◽

Dynamic Regulation ◽

Ph Conditions

Download Full-text

Cytoplasmic Localization of Sulfide:Quinone Oxidoreductase and Persulfide Dioxygenase of Cupriavidus pinatubonensis JMP134

Applied and Environmental Microbiology ◽

10.1128/aem.01820-17 ◽

2017 ◽

Vol 83 (23) ◽

Cited By ~ 5

Author(s):

Rui Gao ◽

Honglei Liu ◽

Luying Xun

Keyword(s):

Organic Pollutants ◽

Soluble Protein ◽

Fluorescent Protein ◽

Heterotrophic Bacteria ◽

Sulfide Oxidation ◽

Periplasmic Space ◽

Microbial Oxidation ◽

Content Type ◽

Sulfide:Quinone Oxidoreductase ◽

Chemolithotrophic Bacteria

ABSTRACT Heterotrophic bacteria have recently been reported to oxidize sulfide to sulfite and thiosulfate by using sulfide:quinone oxidoreductase (SQR) and persulfide dioxygenase (PDO). In chemolithotrophic bacteria, both SQR and PDO have been reported to function in the periplasmic space, with SQR as a peripheral membrane protein whose C terminus inserts into the cytoplasmic membrane and PDO as a soluble protein. Cupriavidus pinatubonensis JMP134, best known for its ability to degrade 2,4-dichlorophenoxyacetic acid and other aromatic pollutants, has a gene cluster of sqr and pdo encoding C. pinatubonensis SQR (CpSQR) and CpPDO2. When cloned in Escherichia coli, the enzymes are functional. Here we investigated whether they function in the periplasmic space or in the cytoplasm in heterotrophic bacteria. By using sequence analysis, biochemical detection, and green fluorescent protein (GFP)/PhoA fusion proteins, we found that CpSQR was located on the cytoplasmic side of the membrane and CpPDO2 was a soluble protein in the cytoplasm with a tendency to be peripherally located near the membrane. The location proximity of these proteins near the membrane in the cytoplasm may facilitate sulfide oxidation in heterotrophic bacteria. The information may guide the use of heterotrophic bacteria in bioremediation of organic pollutants as well as H2S. IMPORTANCE Sulfide (H2S, HS−, and S2−), which is common in natural gas and wastewater, causes a serious malodor at low levels and is deadly at high levels. Microbial oxidation of sulfide is a valid bioremediation method, in which chemolithotrophic bacteria that use sulfide as the energy source are often used to remove sulfide. Heterotrophic bacteria with SQR and PDO have recently been reported to oxidize sulfide to sulfite and thiosulfate. Cupriavidus pinatubonensis JMP134 has been extensively characterized for its ability to degrade organic pollutants, and it also contains SQR and PDO. This paper shows the localization of SQR and PDO inside the cytoplasm in the vicinity of the membrane. The information may provide guidance for using heterotrophic bacteria in sulfide bioremediation.

Download Full-text

Influence of liberation of sulphide minerals on flotation of sedimentary copper ore

E3S Web of Conferences ◽

10.1051/e3sconf/20171801025 ◽

2017 ◽

Vol 18 ◽

pp. 01025

Author(s):

Alicja Bakalarz ◽

Magdalena Duchnowska ◽

Andrzej Luszczkiewicz

Keyword(s):

Particle Size ◽

Ball Mill ◽

Milling Time ◽

Mineral Processing ◽

Copper Ore ◽

Sulphide Minerals ◽

Mineral Liberation ◽

Mineral Production

Ore liberation is one of the most important parameter in mineral processing, especially in flotation. To separate the valuable components from gangue minerals, it is necessary to liberate one from others. It is achieve primarily through crushing and grinding. These stages are one of the most expensive of mineral production. It is important to determine the adequate mineral liberation which would result in huge savings in the overall cost of flotation plant. The aim of the paper was the analysis of the influence of milling time on the laboratory flotation of the copper ore from stratiform Polish deposit. Three different milling time of copper ore in laboratory ball mill was applied. The flotation results were presented as the recovery-recovery and grade-recovery upgrading curves. The liberation of sulphides and the particle size of sulphides in flotation product were analysed and compared.

Download Full-text

The Comparison of Main Copper Sulphide Minerals Beneficiation Under Laboratory and Industrial Conditions at the KGHM Concentration Plant

Inżynieria Mineralna ◽

10.29227/im-2020-01-01 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Paweł KURZYDŁO ◽

Witold PAWLOS

Keyword(s):

Laboratory Tests ◽

Geological Structure ◽

Copper Sulphide ◽

Copper Ore ◽

Ore Deposit ◽

Sulphide Minerals ◽

Concentration Plant ◽

Complex Geological Structure ◽

Process Line

The Zechstein copper ore deposit located on the Foresudetic monocline has a complex geological structure both in lithological and mineralogical aspects. The significant variability in quantity and quality of minerals deposited in the ore bed is one of the factors determining the susceptibility of copper ore to beneficiation based on flotation, which is carried out in the KGHM Concentration Plant. Based on the algorithm developed, flotation experiments on a laboratory scale have been conducted to predict the upgrade rates under industrial conditions. This paper provides the results of the mineralogical examination of the flotation products performed by one of the KGHM Concentration process lines and compares the beneficiation of various copper sulphide minerals. The results of the laboratory tests have been compared with the results of sampling carried out simultaneously at the process line. A procedure has been proposed to develop equations defining the industrial upgradability curves for copper sulphide minerals under the KGHM Concentration Plant conditions.

Download Full-text