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Sample records for copper sulfides

  1. Mechanochemical reduction of copper sulfide

    DEFF Research Database (Denmark)

    Balaz, P.; Takacs, L.; Jiang, Jianzhong

    2002-01-01

    The mechanochemical reduction of copper sulfide with iron was induced in a Fritsch P-6 planetary mill, using WC vial filled with argon and WC balls. Samples milled for specific intervals were analyzed by XRD and Mossbauer spectroscopy. Most of the reaction takes place during the first 10 min...... of milling and only FeS and Cu are found after 60 min. The main chemical process is accompanied by phase transformations of the sulfide phases as a result of milling. Djurleite partially transformed to chalcocite and a tetragonal copper sulfide phase before reduction. The cubic modification of FeS was formed...... first, transforming to hexagonal during the later stages of the process. The formation of off-stoichiometric phases and the release of some elemental sulfur by copper sulfide are also probable....

  2. Solar thermal extraction of copper from sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, L.; Guesdon, C.; Sturzenegger, M.

    2003-03-01

    With the aim to develop a solar-driven process for the extraction of copper from sulfide concentrates re-search on the decomposition of copper sulfides under inert atmospheres has been initiated. Thermogravimetric measurements on chalcocite (Cu{sub 2}S) revealed that copper is formed already at 1823 K. Chalcopyrite (CuFeS{sub 2}) also disintegrates at this temperature, although at a lower rate. Copper and iron have been identified in the solid residue. The results confirm the feasibility of copper extraction by direct decomposition of sulfides under atmospheric pressure. The decomposition under inert atmosphere prevents generation of SO{sub 2}, and is beneficial to the removal of volatile impurities. Chemical equilibrium calculations for CuFeS{sub 2} contaminated with enargite (Cu{sub 3}AsS{sub 4}) have shown that the absence of an oxidic slag allows for a complete evaporation of arsenic and subsequent separation. (author)

  3. A study of the stability of cadmium sulfide/copper sulfide and cadmium sulfide copper-indium-diselenide solar cells

    Science.gov (United States)

    Noel, G.; Richard, N.; Gaines, G.

    1984-08-01

    Groups of high efficiency cadmium sulfide/copper sulfide solar cells were exposed to combinations of stresses designed to isolate and accelerate intrinsic degradation mechanisms. Stresses included elevated temperature, illumination intensity, and cell loading conditions. All stress exposures and tests were conducted in a benign (high purity argon) atmosphere. Two primary intrinsic modes of degradation were identified: degradation of the open circuit voltage under continuous illumination and nonzero loading was found to be self recovering upon interruption of illumination or upon shorting or reverse biasing the cells. It was attributed to traps in the depletion region. Recovery from decay of light generated current was not spontaneous but could be partially accomplished by annealing in a reducing (hydrogen) environment. It was attributed to changes in the stoichiometry of the copper sulfide under the influence of electric fields and currents.

  4. Kinetics of the conversion of copper sulfide to blister copper

    Directory of Open Access Journals (Sweden)

    Carrillo, F.

    2002-10-01

    Full Text Available The desulfurization of copper sulfide by air and oxygen has been studied in two laboratory reactors where the gas is blown onto the melt surface. Rates of oxidation in a vertical resistance furnace may be explained by the mass transfer control in the gas phase. However, results for a horizontal tube suggest that the chemical resistance is controlling.

    La desulfuración del sulfuro cuproso con aire y oxígeno se ha estudiado en dos reactores de laboratorio, en los cuales el gas se sopla sobre la superficie del fundido. La velocidad de reacción en un horno de resistencias verticales se puede explicar considerando como controlante la resistencia a la transferencia de materia de la fase gas. Sin embargo, los resultados del horno horizontal indican que la resistencia química es la controlante.

  5. Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

    Science.gov (United States)

    Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

    2006-11-02

    The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.

  6. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent. Part 2. The regeneration of copper sulfide to copper oxide - An experimental study

    NARCIS (Netherlands)

    ter Maat, Hendrik; ter Maat, H.; Hogendoorn, Kees; Versteeg, Geert

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to

  7. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part II. the regeneration of copper sulfide to copper oxide - An experimental study

    NARCIS (Netherlands)

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to 75

  8. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent: Part II. The regeneration of copper sulfide to copper oxide—an experimental study

    NARCIS (Netherlands)

    Maat, ter H.; Hogendoorn, J.A.; Versteeg, G.F.

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to 75

  9. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part II. the regeneration of copper sulfide to copper oxide - An experimental study

    NARCIS (Netherlands)

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to

  10. Dynamic corrosion of copper-nickel sulfide by Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    TONG Lin-lin; JIANG Mao-fa; YANG Hong-ying; YU Juan; FAN You-jing; ZHANG Yao

    2009-01-01

    The dynamic corrosion process of bio-oxidation of copper-nickel sulfide from Karatungk in northern Xinjiang Province of China was studied. The polished wafer of the copper-nickel sulphide was used to carry on a series of oxidation corrosion experiment by Acidithiobacillus ferrooxidans. The changes of superficial corrosion appearance and the mineral dynamic corrosion process were discovered by microscope observation. Then, the galvanic cell model was established, and the bio-oxidation activation order of typical copper-nickel sulphide minerals was ascertained as pyrrhotite>pentlandite>chalocopyrite.

  11. Structural studies of copper sulfide films: effect of ambient atmosphere

    Directory of Open Access Journals (Sweden)

    Manisha Kundu et al

    2008-01-01

    Full Text Available We examined the structural properties of copper sulfide films as a function of the sulfurization time of 70-nm-thick Cu films. Copper sulfide films with various phases such as mixed metallic Cu-chalcocite, chalcocite, roxbyite, and covellite phases were formed with increasing sulfurization time. To evaluate the structural stability of various films, all the films were exposed to the ambient atmosphere for the same amount of time. Although the phase structure and stoichiometry of the films were maintained at a greater depth, the near-surface region of the films was oxidized and covered with overlayers of oxide, hydroxide, and/or sulfate species due to the exposure and reaction with the ambient atmosphere. The oxygen uptake and its reactivity with the copper sulfide film surfaces were enhanced with increasing sulfur content of the films. In addition, the type of divalent state of copper formed on the film surfaces depended on the phase structure, composition, and stoichiometry of the films.

  12. Fabrication and applications of copper sulfide (CuS) nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Shamraiz, Umair, E-mail: umairshamraiz@gmail.com; Hussain, Raja Azadar, E-mail: hussainazadar@gamil.com; Badshah, Amin, E-mail: aminbadshah@yahoo.com

    2016-06-15

    This review article presents different fabrication procedures (under the headlines of solvothermal routes, aerosol methods, solution methods and thermolysis), and applications (photocatalytic degradation, ablation of cancer cells, electrode material in lithium ion batteries and in gas sensing, organic solar cells, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, electrochemical bio sensing, enhanced PEC characteristics of pre-annealed CuS film electrodes) of copper sulfide (Covellite). - Highlights: • This review article presents the synthesis and applications of copper sulfide. • CuS has been used over the years for different applications in nanoscience. • Different synthetic protocols are followed for their preparation which help in the possible modifications in the morphology of CuS.

  13. Formation of Submicron Copper Sulfide Particles Using Spray Pyrolysis Method

    Science.gov (United States)

    Lenggoro, I.; Kang, Yun; Komiya, Takafumi; Okuyama, Kikuo; Tohge, Noboru

    1998-03-01

    The morphology and crystalline phase of submicron copper sulfide particles prepared by spray pyrolysis method have been studied. In a nitrogen gas atmosphere, the covellite phase (CuS) spherical particles could be prepared using the solution with molar ratio of copper nitrate to thiourea and furnace temperatures of 1:2 at 200 300°C, as well as of 1:5 at 200 600°C. The crystalline phase of particles was highly depended on the composition of the precursors and the pyrolysis temperature. The sphericity of particles could be enhanced by increasing the temperature and prolonging the residence time of the droplets or particles in the furnace.

  14. Fabrication and applications of copper sulfide (CuS) nanostructures

    Science.gov (United States)

    Shamraiz, Umair; Hussain, Raja Azadar; Badshah, Amin

    2016-06-01

    This review article presents different fabrication procedures (under the headlines of solvothermal routes, aerosol methods, solution methods and thermolysis), and applications (photocatalytic degradation, ablation of cancer cells, electrode material in lithium ion batteries and in gas sensing, organic solar cells, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, electrochemical bio sensing, enhanced PEC characteristics of pre-annealed CuS film electrodes) of copper sulfide (Covellite).

  15. Chemical Precipitation Synthesis and Thermoelectric Properties of Copper Sulfide

    Science.gov (United States)

    Wu, Sixin; Jiang, Jing; Liang, Yinglin; Yang, Ping; Niu, Yi; Chen, Yide; Xia, Junfeng; Wang, Chao

    2017-04-01

    Earth-abundant copper sulfide compounds have been intensively studied as potential thermoelectric materials due to their high dimensionless figure of merit ZT values. They have a unique phonon-liquid electron-crystal model that helps to achieve high thermoelectric performance. Many methods, such as melting and ball-milling, have been adopted to synthesize this copper sulfide compound, but they both use expensive starting materials with high purity. Here, we develop a simple chemical precipitation approach to synthesize copper sulfide materials through low-cost analytically pure compounds as the starting materials. A high ZT value of 0.93 at 800 K was obtained from the samples annealed at 1273 K. Its power factor is around 8.0 μW cm-1 K-2 that is comparable to the highest record reported by traditional methods. But, the synthesis here has been greatly simplified with reduced cost, which will be of great benefit to the potential mass production of thermoelectric devices. Furthermore, this method can be applied to the synthesis of other sulfur compound thermoelectric materials.

  16. L-Cysteine-assisted Synthesis of Copper Gallium Sulfide Microspheres

    Institute of Scientific and Technical Information of China (English)

    LIANG Xiao-juan; ZHONG Jia-song; CAI Qian; HUANG Hai-yu; LIU Hai-tao; XIANG Wei-dong; SUN Jun-cai

    2012-01-01

    An effective L-cysteine-assisted synthetic route has been successfully developed to prepare copper gallium sulfide(CuGaS2) microspheres under solvothermal conditions with CuCI2-2H2O,GaCl3 and L-cysteine as source materials,in which L-cysteine was used as the sulfide source and eomplexing molecule.The experiments revealed that the synthesized sample was of a typical CuGaS2 tetragonal structure.Moreover,the prepared CuGaS2 crystals consisting of microspheres made up of nanoflakes,and the diameter of the nanoflakes was about 20 nm.Raman spectrum of the obtained CuGaS2 exhibits a high-intensity peak of the A1 mode at 306 cm-1.Meanwhile,a possible growth mechanism was proposed based on the investigations.

  17. Facile aqueous-phase synthesis of copper sulfide nanofibers

    Science.gov (United States)

    Tang, Zengmin; Im, Sang Hyuk; Kim, Woo-Sik; Yu, Taekyung

    2017-07-01

    We report a facile aqueous-phase synthetic route to vine-like copper sulfide (CuS) nanofibers prepared by reacting elemental sulfur with Cu+-branched polyethyleneimine (BPEI) complex obtained by the reaction of Cu2+ with ascorbic acid in the presence of BPEI. By controlling the concentration of BPEI, we could easily control the morphology of CuS from nanofibers to hollow nanoparticles. We also found that concentration of BPEI and the presence of halide anion would play important roles in the formation of vine-like CuS nanofibers.

  18. Fundamental features of copper ion precipitation using sulfide as a precipitant in a wastewater system.

    Science.gov (United States)

    Choi, Jung-Yoon; Kim, Dong-Su; Lim, Joong-Yeon

    2006-01-01

    We have investigated the precipitation features of copper ion using sulfide as a precipitant by varying the mole ratio of sulfide to copper ion, pH, temperature and the kind and concentration of complexing agent. In the precipitation of copper ion by sulfide, sludge is produced as cupric sulfide; thus, there is a possibility for its recycled use in photochemical and ceramic processes. When the ratio of the concentration of copper ion to sulfide was increased to more than 1.0, the extent of precipitation was very high. As the ratio was increased, nucleation time was decreased and crystal growth rate was raised. The higher the pH, the greater the amount of precipitated copper ion due to lowered solubility of cupric sulfide. When temperature changed from 25 degrees C to 55 degrees C, the precipitation of copper ion was increased a little. On the basis of estimated thermodynamic parameters such as Gibbs free energy and enthalpy, the precipitation reaction was spontaneous and endothermic. The precipitation of copper ion was lowered in the presence of complexing agent and it was affected by the stability of the copper complex. The feasibility test for the application of precipitation treatment to actual wastewater containing copper ion showed, although there was a little decrease in the removal of copper, the precipitation extent of copper was higher than 90% compared with that for artificial wastewater.

  19. Effect of Sulfide Concentration on Copper Corrosion in Anoxic Chloride-Containing Solutions

    Science.gov (United States)

    Kong, Decheng; Dong, Chaofang; Xu, Aoni; Man, Cheng; He, Chang; Li, Xiaogang

    2017-02-01

    The structure and property of passive film on copper are strongly dependent on the sulfide concentration; based on this, a series of electrochemical methods were applied to investigate the effect of sulfide concentration on copper corrosion in anaerobic chloride-containing solutions. The cyclic voltammetry and x-ray photoelectron spectroscopy analysis demonstrated that the corrosion products formed on copper in anaerobic sulfide solutions comprise Cu2S and CuS. And the corrosion resistance of copper decreased with increasing sulfide concentration and faster sulfide addition, owing to the various structures of the passive films observed by the atomic force microscope and scanning electron microscope. A p-type semiconductor character was obtained under all experimental conditions, and the defect concentration, which had a magnitude of 1022-1023 cm-3, increased with increasing sulfide concentration, resulting in a higher rate of both film growth and dissolution.

  20. Multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates.

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ken Shuang

    2004-11-01

    This report documents the author's efforts in the deterministic modeling of copper-sulfidation corrosion on non-planar substrates such as diodes and electrical connectors. A new framework based on Goma was developed for multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates. In this framework, the moving sulfidation front is explicitly tracked by treating the finite-element mesh as a pseudo solid with an arbitrary Lagrangian-Eulerian formulation and repeatedly performing re-meshing using CUBIT and re-mapping using MAPVAR. Three one-dimensional studies were performed for verifying the framework in asymptotic regimes. Limited model validation was also carried out by comparing computed copper-sulfide thickness with experimental data. The framework was first demonstrated in modeling one-dimensional copper sulfidation with charge separation. It was found that both the thickness of the space-charge layers and the electrical potential at the sulfidation surface decrease rapidly as the Cu{sub 2}S layer thickens initially but eventually reach equilibrium values as Cu{sub 2}S layer becomes sufficiently thick; it was also found that electroneutrality is a reasonable approximation and that the electro-migration flux may be estimated by using the equilibrium potential difference between the sulfidation and annihilation surfaces when the Cu{sub 2}S layer is sufficiently thick. The framework was then employed to model copper sulfidation in the solid-state-diffusion controlled regime (i.e. stage II sulfidation) on a prototypical diode until a continuous Cu{sub 2}S film was formed on the diode surface. The framework was also applied to model copper sulfidation on an intermittent electrical contact between a gold-plated copper pin and gold-plated copper pad; the presence of Cu{sub 2}S was found to raise the effective electrical resistance drastically. Lastly, future research needs in modeling atmospheric copper sulfidation are discussed.

  1. Accelerating column leaching trial on copper sulfide ore

    Institute of Scientific and Technical Information of China (English)

    WANG Hongjiang; WU Aixiang; ZHOU Xun; WANG Shaoyong; ZHANG Jie

    2008-01-01

    The main measures to accelerate leaching sulfide ore are large spraying intensity,manual oxygen supply,temperature control and acclimated bacteria.The indoor experiment accelerating sulfide ore leaching detected the temperature during leaching process,dissolvability of oxygen,bacterial concentration,Cu concentration and slag grade.At the same time,this paper also analyzed the effect of four factors,which are bacterial diversity cultivation stage,spraying intensity,air supply,and whether to control temperature,on the leaching efficiency of copper.The results indicate that the oxygen content of leach solution has a close relationship with temperature but it is rarely affected by air supply.The bacterial concentration preserves from 106 to 107 mL-1,and temperature has a great effect on the bacterial activity under the condition of proper temperature and oxygen supply,and the lack of nutrition prevents the bacterial concentration from rising in the late stage.The relationships of the copper leaching efficiency to temperature,air feed,and spraying intensity are directly proportional.The leaching efficiencies of the cultivated bacteria and acclimation bacteria are 1.2 and 1.4 times as large as that of the original bacteria.

  2. Electrically Conducting Polymer-Copper Sulphide Composite Films, Preparation by Treatment of Polymer-Copper (2) Acetate Composites with Hydrogen Sulfide

    Science.gov (United States)

    Yamamoto, Takakazu; Kamigaki, Takahira; Kubota, Etsuo

    1988-01-01

    Polymer copper sulfide composite films were prepared by treatment of polymer poly(vinyl chloride), poly(acrylonitrile), copolymer of vinyl chloride and vinyl acetate (90:10), and ABS resin copper (2) acetate composites with hydrogen sulfide. The films showed electrical conductivity higher than 0.015 S/cm when they contained more than 20 wt percent of copper sulfide. A poly(acrylonitrile)-copper sulfide composite film containing 40 to 50 wt percent of copper sulfide showed electrical conductivity of 10 to 150.0 S/cm and had relatively high mechanical strength to be used in practical purposes.

  3. Electrochemistry of Molten Sulfides: Copper Extraction from BaS-Cu[subscript 2]S

    OpenAIRE

    Sokhanvaran, Samira; Lee, Sang-Kwon; Lambotte, Guillaume; Allanore, Antoine

    2015-01-01

    The electrolytic extraction of liquid copper at 1105°C from a molten sulfide electrolyte composed of 57 wt% BaS and 43 wt% Cu[subscript 2]S was investigated. DC cyclic voltammetry, Fourier transformed AC voltammetry, and galvanostatic electrolysis revealed that the electrodeposition of copper is possible in the selected molten sulfide electrolyte. The half wave potential for the reaction on graphite was determined, and liquid copper of high purity was obtained by galvanostatic electrolysis. T...

  4. Atomic layer deposition of copper sulfide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Nathanaelle, E-mail: n.schneider@chimie-paristech.fr; Lincot, Daniel; Donsanti, Frédérique

    2016-02-01

    Atomic Layer Deposition (ALD) of copper sulfide (Cu{sub x}S) thin films from Cu(acac){sub 2} (acac = acetylacetonate = 2,4-pentanedionate) and H{sub 2}S as Cu and S precursors is reported. Typical self-saturated reactions (“ALD window”) are obtained in the temperature range T{sub dep} = 130–200 °C for an average growth per cycle (GR) = 0.25 Å/cycle. The morphology, crystallographic structure, chemical composition, electrical properties and optical band gap of thin films were investigated using scanning electronic microscopy (SEM), X-ray diffraction under Grazing Incidence conditions (GI-XRD), X-ray reflectivity (XRR), energy dispersive spectrometry (EDS), Hall effect measurements, and UV–vis spectroscopy. The obtained copper sulfide films are heavily p-doped (charge carrier concentration ~ 10{sup 21} –10{sup 22} cm{sup −3}) with optical band gaps in the range of 2.2–2.5 eV for direct and 1.6–1.8 eV for indirect band gaps. Depending on the number of ALD cycles, multiphase compounds (made of digenite Cu{sub 1.8}S, chalcocite Cu{sub 2}S, djurleite Cu{sub 31}S{sub 16} and covellite CuS) or single-phase digenite Cu{sub 1.8}S films are obtained via a growth mechanism that involves in-situ copper reduction and loss of sulfur by evaporation. - Highlights: • Cu{sub x}S films were synthesized by atomic layer deposition from Cu(acac){sub 2} and H{sub 2}S. • Self-saturated reactions at T{sub dep} = 130–200 °C for growth = 0.25 Å/cycle • Multi- or single- phase films are obtained depending on the number of cycles. • Growth mechanism involves copper reduction and loss of sulfur by evaporation.

  5. VAPOR PHASE MERCURY SORPTION BY ORGANIC SULFIDE MODIFIED BIMETALLIC IRON-COPPER NANOPARTICLE AGGREGATES

    Science.gov (United States)

    Novel organic sulfide modified bimetallic iron-copper nanoparticle aggregate sorbent materials have been synthesized for removing elemental mercury from vapor streams at elevated temperatures (120-140 °C). Silane based (disulfide silane and tetrasulfide silane) and alkyl sulfide ...

  6. Catalytic effect of activated carbon on bioleaching of low-grade primary copper sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The catalytic effect of activated carbon on the bioleaching of low-grade primary copper sulfide ores using mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was investigated. The results show that the addition of activated carbon can greatly accelerate the rate and efficiency of copper dissolution from low-grade primary copper sulfide ores. The solution with the concentration of 3.0 g/L activated carbon is most beneficial to the dissolution of copper. The resting time of the mixture of activated carbon and ores has an impact on the bioleaching of low-grade primary copper sulfide ores. The 2 d resting time is most favorable to the dissolution of copper. The enhanced dissolution rate and efficiency of copper can be attributed to the galvanic interaction between activated carbon and chalcopyrite. The addition of activated carbon obviously depresses the dissolution of iron and the bacterial oxidation of ferrous ions in solution. The lower redox potentials are more favorable to the copper dissolution than the higher potentials for low-grade primary copper sulfide ores in the presence of activated carbon.

  7. Simulated small-scale pilot heap leaching of low-grade copper sulfide ore with selective extraction of copper

    Institute of Scientific and Technical Information of China (English)

    QIN Wen-qing; ZHANG Yan-sheng; LI Wei-zhong; WANG Jun

    2008-01-01

    The bioleaching of low-grade copper sulfide ore and the selective extraction of copper were investigated.Lix984 dissolved in kerosene was used as extractant.The results show that it is possible to selectively leach copper from the ores by heap leaching.The copper concentration of leaching liquor after 250 d is 2.17 g/L,and the copper concentration is 0.27 g/L after solvent extraction.The leach liquor was subjected to solvent extraction,scrubbing and selective stripping for the enrichment of copper and the removal of impurities.The pregnant copper sulfate solution produced from the stripping cycle is suitable for copper electro-winning.

  8. Effect of sulfide pollution on the stability of the protective film of benzotriazole on copper

    Energy Technology Data Exchange (ETDEWEB)

    Al Kharafi, F.M. [Chemistry Department, Faculty of Science, Kuwait University (Kuwait)], E-mail: fayzah@aas.com.kw; Abdullah, A.M.; Ghayad, I.M. [Chemistry Department, Faculty of Science, Kuwait University (Kuwait); Ateya, B.G. [Chemistry Department, Faculty of Science, Kuwait University (Kuwait)], E-mail: bgateya@yahoo.com

    2007-09-15

    Benzotriazole (BTAH) is an excellent inhibitor for the corrosion of copper and many of its alloys in unpolluted media. Protection is attributed to the formation of a film of Cu(I)BTA. Injection of sulfide ions into a benzotriazole inhibited salt water damages the protective Cu(I)BTA film very rapidly, increases the corrosion rate and leads to the formation of copper sulfide. This effect is quite marked at a sulfide concentration as low as 10{sup -5} M (about 0.3 ppm sulfur) in the presence of 10{sup -2} M BTAH, which is 1000-fold greater than that of the sulfide ion. The intensity of sulfide attack increases with its concentration. Prolonged pre-passivation of copper in the BTAH protected medium even at high concentration does not markedly improve the resistance of the protective film to sulfide attack. This finding is contrary to a well-documented phenomenon in unpolluted media where the inhibiting efficiency of BTAH increases with the time of immersion and the concentration of the inhibitor. X-ray photoelectron spectroscopy (XPS) reveals the presence of both sulfide and BTAH on the corroded surface indicating that sulfide attack is localized.

  9. Some properties of copper and selected heavy metal sulfides. A limited literature review

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P. [Studsvik Material AB, Nykoeping (Sweden)

    1995-06-01

    In the SKB proposal for a Swedish nuclear waste repository, copper canisters are used for encapsulating the spent fuel. The chemical and physical behavior of Copper in the repository environment will therefore be of critical importance for the repository integrity. The present work concerns a literature review of Copper and selected heavy metal sulfides as they are expected to play an important role in the repository environment. The interest is focused on their properties as described by crystal structure, electrical properties, atom mobility, solubility in water, mechanisms of sulfidation and selected thermodynamical data. 56 refs, 14 figs, 5 tabs.

  10. Sulfide oxidation as a process for the formation of copper-rich magmatic sulfides

    Science.gov (United States)

    Wohlgemuth-Ueberwasser, Cora C.; Fonseca, Raúl O. C.; Ballhaus, Chris; Berndt, Jasper

    2013-01-01

    Typical magmatic sulfides are dominated by pyrrhotite and pentlandite with minor chalcopyrite, and the bulk atomic Cu/Fe ratio of these sulfides is typically less than unity. However, there are rare magmatic sulfide occurrences that are dominated by Cu-rich sulfides (e.g., bornite, digenite, and chalcopyrite, sometimes coexisting with metallic Cu) with atomic Cu/Fe as high as 5. Typically, these types of sulfide assemblages occur in the upper parts of moderately to highly fractionated layered mafic-ultramafic intrusions, a well-known example being the Pd/Au reef in the Upper Middle Zone of the Skaergaard intrusion. Processes proposed to explain why these sulfides are so unusually rich in Cu include fractional crystallization of Fe/(Ni) monosulfide and infiltration of postmagmatic Cu-rich fluids. In this contribution, we explore and experimentally evaluate a third possibility: that Cu-rich magmatic sulfides may be the result of magmatic oxidation. FeS-dominated Ni/Cu-bearing sulfides were equilibrated at variable oxygen fugacities in both open and closed system. Our results show that the Cu/Fe ratio of the sulfide melt increases as a function of oxygen fugacity due to the preferential conversion of FeS into FeO and FeO1.5, and the resistance of Cu2S to being converted into an oxide component even at oxygen fugacities characteristic of the sulfide/sulfate transition (above FMQ + 1). This phenomenon will lead to an increase in the metal/S ratio of a sulfide liquid and will also depress its liquidus temperature. As such, any modeling of the sulfide liquid line of descent in magmatic sulfide complexes needs to address this issue.

  11. Self-assembly of Copper Sulfide Nanoparticles to Solid, Hollow Spherical and Wire-Shaped Structures

    Institute of Scientific and Technical Information of China (English)

    NAN Zhao-Dong; WEI Cheng-Zhen; WANG Xue-Ying; HAO Hai-Yan

    2008-01-01

    Copper sulfides, such as Cu7S4, Cu1.8S, Cu1.81S and Cu2S, in the wire-like, and solid and hollow ball-like shapes congregated from nano-spherical particles and nanoslices, have been prepared by a solvothermal method using a mixture of water and ethylene glycol as solvent. CuSO4 and thiourea were used as the starting materials without as- sistance of any surfactant or template. The results show that the water content in the solvent affects the morphology of the samples, and the reaction time and temperature affect the crystal structure and morphology. On the basis of the obtained results, the formation processes of different morphologies of copper sulfides can be interpreted by the following mechanism: nanoparticles of copper sulfides initially formed, then the wire-like structures were gradually created, and finally translated to solid and hollow spherical structures under the different experimental conditions.

  12. The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

    Directory of Open Access Journals (Sweden)

    Živković Živan

    2009-01-01

    Full Text Available This paper presents the results of multi-linear regression analysis (MLRA of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3 and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974. This indicates that slag composition and content of copper in the matte influences the copper losses in the waste slag with the probability of 95 %.

  13. The effects of varying humidity on copper sulfide film formation.

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Thomas Michael; Missert, Nancy A.; Barbour, John Charles; Sullivan, John Patrick; Copeland, Robert Guild; Campin, Michael J. (International Sematech, Austin, TX)

    2004-02-01

    Detailed experiments involving extensive high resolution transmission electron microscopy (TEM) revealed significant microstructural differences between Cu sulfides formed at low and high relative humidity (RH). It was known from prior experiments that the sulfide grows linearly with time at low RH up to a sulfide thickness approaching or exceeding one micron, while the sulfide initially grows linearly with time at high RH then becomes sub-linear at a sulfide thickness less than about 0.2 microns, with the sulfidation rate eventually approaching zero. TEM measurements of the Cu2S morphology revealed that the Cu2S formed at low RH has large sized grains (75 to greater than 150 nm) that are columnar in structure with sharp, abrupt grain boundaries. In contrast, the Cu2S formed at high RH has small equiaxed grains of 20 to 50 nm in size. Importantly, the small grains formed at high RH have highly disordered grain boundaries with a high concentration of nano-voids. Two-dimensional diffusion modeling was performed to determine whether the existence of localized source terms at the Cu/Cu2S interface could be responsible for the suppression of Cu sulfidation at long times at high RH. The models indicated that the existence of static localized source terms would not predict the complete suppression of growth that was observed. Instead, the models suggest that the diffusion of Cu through Cu2S becomes restricted during Cu2S formation at high RH. The leading speculation is that the extensive voiding that exists at grain boundaries in this material greatly reduces the flux of Cu between grains, leading to a reduction in the rate of sulfide film formation. These experiments provide an approach for adding microstructural information to Cu sulfidation rate computer models. In addition to the microstructural studies, new micro-patterned test structures were developed in this LDRD to offer insight into the point defect structure of Cu2S and to permit measurement of surface reaction

  14. Effect of copper dosing on sulfide inhibited reduction of nitric and nitrous oxide

    NARCIS (Netherlands)

    Manconi, I.; Maas, van der P.M.F.; Lens, P.N.L.

    2006-01-01

    The stimulating effect of copper addition on the reduction rate of nitrous oxide (N2O) to dinitrogen (N2) in the presence of sulfide was investigated in batch experiments (pH 7.0; 55 °C). N2O was dosed either directly as a gas to the headspace of the bottles or formed as intermediate during the deni

  15. Direct synthesis of diaryl sulfides by copper-catalyzed coupling of aryl halides with aminothiourea

    Institute of Scientific and Technical Information of China (English)

    Xiang Mei Wu; Wei Ya Hu

    2012-01-01

    An efficient and simple protocol of copper-catalyzed C-S bond formation between aryl halides and inexpensive and commercially available aminothiourea is reported.A variety of symmetrical diaryl sulfides can be synthesized in good to excellent yields up to 94% with the advantage of avoiding foul-smelling thiols.

  16. Statistical modeling of copper losses in the silicate slag of the sulfide concentrate smelting process

    OpenAIRE

    2015-01-01

    This article presents the results of the statistical modeling of copper losses in the silicate slag of the sulfide concentrates smelting process. The aim of this study was to define the correlation dependence of the degree of copper losses in the silicate slag on the following parameters of technological processes: SiO2, FeO, Fe3O4, CaO and Al2O3 content in the slag and copper content in the matte. Multiple linear regression analysis (MLRA), artificial neural networks (ANNs) and adaptive netw...

  17. The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

    OpenAIRE

    2009-01-01

    This paper presents the results of multi-linear regression analysis (MLRA) of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3) and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974). This indicates that slag composition and content of copper in t...

  18. Copper zinc tin sulfide-based thin film solar cells

    CERN Document Server

    Ito, Kentaro

    2014-01-01

    Beginning with an overview and historical background of Copper Zinc Tin Sulphide (CZTS) technology, subsequent chapters cover properties of CZTS thin films, different preparation methods of CZTS thin films, a comparative study of CZTS and CIGS solar cell, computational approach, and future applications of CZTS thin film solar modules to both ground-mount and rooftop installation. The semiconducting compound (CZTS) is made up earth-abundant, low-cost and non-toxic elements, which make it an ideal candidate to replace Cu(In,Ga)Se2 (CIGS) and CdTe solar cells which face material scarcity and tox

  19. Statistical modeling of copper losses in the silicate slag of the sulfide concentrate smelting process

    Directory of Open Access Journals (Sweden)

    Savic Marija V.

    2015-09-01

    Full Text Available This article presents the results of the statistical modeling of copper losses in the silicate slag of the sulfide concentrates smelting process. The aim of this study was to define the correlation dependence of the degree of copper losses in the silicate slag on the following parameters of technological processes: SiO2, FeO, Fe3O4, CaO and Al2O3 content in the slag and copper content in the matte. Multiple linear regression analysis (MLRA, artificial neural networks (ANNs and adaptive network based fuzzy inference system (ANFIS were used as tools for mathematical analysis of the indicated problem. The best correlation coefficient (R2 = 0.719 of the final model was obtained using the ANFIS modeling approach.

  20. Fabrication of a Functionally Graded Copper-Zinc Sulfide Phosphor.

    Science.gov (United States)

    Park, Jehong; Park, Kwangwon; Kim, Jongsu; Jeong, Yongseok; Kawasaki, Akira; Kwon, Hansang

    2016-03-14

    Functionally graded materials (FGMs) are compositionally gradient materials. They can achieve the controlled distribution of the desired characteristics within the same bulk material. We describe a functionally graded (FG) metal-phosphor adapting the concept of the FGM; copper (Cu) is selected as a metal and Cu- and Cl-doped ZnS (ZnS:Cu,Cl) is selected as a phosphor and FG [Cu]-[ZnS:Cu,Cl] is fabricated by a very simple powder process. The FG [Cu]-[ZnS:Cu,Cl] reveals a dual-structured functional material composed of dense Cu and porous ZnS:Cu,Cl, which is completely combined through six graded mediating layers. The photoluminescence (PL) of FG [Cu]-[ZnS:Cu,Cl] is insensitive to temperature change. FG [Cu]-[ZnS:Cu,Cl] also exhibits diode characteristics and photo reactivity for 365 nm -UV light. Our FG metal-phosphor concept can pave the way to simplified manufacturing of low-cost and can be applied to various electronic devices.

  1. Microbial Ecology Assessment of Mixed Copper Oxide/Sulfide Dump Leach Operation

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, D F; Thompson, D N; Noah, K S

    1999-06-01

    Microbial consortia composed of complex mixtures of autotrophic and heterotrophic bacteria are responsible for the dissolution of metals from sulfide minerals. Thus, an efficient copper bioleaching operation depends on the microbial ecology of the system. A microbial ecology study of a mixed oxide/sulfide copper leaching operation was conducted using an "overlay" plating technique to differentiate and identify various bacterial consortium members of the genera Thiobacillus, Leptospirillum, Ferromicrobium, and Acidiphilium. Two temperatures (30C and 45C) were used to select for mesophilic and moderately thermophilic bacteria. Cell numbers varied from 0-106 cells/g dry ore, depending on the sample location and depth. After acid curing for oxide leaching, no viable bacteria were recovered, although inoculation of cells from raffinate re-established a microbial population after three months. Due to the low pH of the operation, very few non-iron-oxidizing acidophilic heterotrophs were recovered. Moderate thermophiles were isolated from the ore samples. Pregnant liquor solutions (PLS) and raffinate both contained a diversity of bacteria. In addition, an intermittently applied waste stream that contained high levels of arsenic and fluoride was tested for toxicity. Twenty vol% waste stream in PLS killed 100% of the cells in 48 hours, indicating substantial toxicity and/or growth inhibition. The data indicate that bacteria populations can recover after acid curing, and that application of the waste stream to the dump should be avoided. Monitoring the microbial ecology of the leaching operation provided significant information that improved copper recovery.

  2. Formation of Hydrogen Sulfide in Wine: Interactions between Copper and Sulfur Dioxide

    OpenAIRE

    Marlize Z. Bekker; Smith, Mark E.; Smith, Paul A.; Eric N. Wilkes

    2016-01-01

    The combined synergistic effects of copper (Cu2+) and sulfur dioxide (SO2) on the formation of hydrogen sulfide (H2S) in Verdelho and Shiraz wine samples post-bottling was studied over a 12-month period. The combined treatment of Cu2+ and SO2 significantly increased H2S formation in Verdelho wines samples that were not previously treated with either Cu2+ or SO2. The formation of H2S produced through Cu2+ mediated reactions was likely either: (a) directly through the interaction of SO2 with ei...

  3. Synthesis and Characterization of Bovine Serum Albumin-Conjugated Copper Sulfide Nanocomposites

    Directory of Open Access Journals (Sweden)

    Peng Huang

    2010-01-01

    Full Text Available A simple biomolecule-assisted solution route was developed to synthesize Bovine Serum Albumin-conjugated copper sulfide (CuS/BSA nanocomposites, directly using copper salts and thioacetamide (TAA as the starting materials with a zwitterionic surfactant Bovine Serum Albumin (BSA as foaming and stabilizing agent. The CuS/BSA nanocomposites have been characterized by UV, TEM, Zeta, DLS, XRD, and FTIR. The results indicate that the as-prepared CuS/BSA nanocomposites are approximate sphere with a size distribution from 10 to 35 nm in diameter and good dispersibility, depending highly on concentration of BSA concentration. These protein-assisted synthesized nanocomposites have a great potential application in biomedical engineering and microelectronics.

  4. Nontoxic and abundant copper zinc tin sulfide nanocrystals for potential high-temperature thermoelectric energy harvesting.

    Science.gov (United States)

    Yang, Haoran; Jauregui, Luis A; Zhang, Genqiang; Chen, Yong P; Wu, Yue

    2012-02-01

    Improving energy/fuel efficiency by converting waste heat into electricity using thermoelectric materials is of great interest due to its simplicity and reliability. However, many thermoelectric materials are composed of either toxic or scarce elements. Here, we report the experimental realization of using nontoxic and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS nanocrystals can be synthesized in large quantities from solution phase reaction and compressed into robust bulk pellets through spark plasma sintering and hot press while still maintaining nanoscale grain size inside. Electrical and thermal measurements have been performed from 300 to 700 K to understand the electron and phonon transports. Extra copper doping during the nanocrystal synthesis introduces a significant improvement in the performance.

  5. Bioflotation of sulfide minerals with Acidithiobacillus ferrooxidans in relation to copper activation and surface oxidation.

    Science.gov (United States)

    Pecina-Treviño, E T; Ramos-Escobedo, G T; Gallegos-Acevedo, P M; López-Saucedo, F J; Orrantia-Borunda, E

    2012-08-24

    Surface oxidation of sulfides and copper (Cu) activation are 2 of the main processes that determine the efficiency of flotation. The present study was developed with the intention to ascertain the role of the phenomena in the biomodification of sulfides by Acidithiobacillus ferrooxidans culture (cells and growth media) and their impact in bioflotation. Surface characteristics of chalcopyrite, sphalerite, and pyrrhotite, alone and in mixtures, after interaction with A. ferrooxidans were evaluated. Chalcopyrite floatability was increased substantially by biomodification, while bacteria depressed pyrrhotite floatability, favoring separation. The results showed that elemental sulfur concentration increased because of the oxidation generated by bacterial cells, the effect is intensified by the Fe(III) left in the culture and by galvanic contact. Acidithiobacillus ferrooxidans culture affects the Cu activation of sphalerite. The implications of elemental sulfur concentration and Cu activation of sphalerite are key factors that must be considered for the future development of sulfide bioflotation processes, since the depressive effect of cells could be counteracted by elemental sulfur generation.

  6. Synthesis, Deposition, and Microstructure Development of Thin Films Formed by Sulfidation and Selenization of Copper Zinc Tin Sulfide Nanocrystals

    Science.gov (United States)

    Chernomordik, Boris David

    Significant reduction in greenhouse gas emission and pollution associated with the global power demand can be accomplished by supplying tens-of-terawatts of power with solar cell technologies. No one solar cell material currently on the market is poised to meet this challenge due to issues such as manufacturing cost, material shortage, or material toxicity. For this reason, there is increasing interest in efficient light-absorbing materials that are comprised of abundant and non-toxic elements for thin film solar cell. Among these materials are copper zinc tin sulfide (Cu2ZnSnS4, or CZTS), copper zinc tin selenide (Cu2ZnSnSe4, or CZTSe), and copper zinc tin sulfoselenide alloys [Cu2ZnSn(SxSe1-x )4, or CZTSSe]. Laboratory power conversion efficiencies of CZTSSe-based solar cells have risen to almost 13% in less than three decades of research. Meeting the terawatt challenge will also require low cost fabrication. CZTSSe thin films from annealed colloidal nanocrystal coatings is an example of solution-based methods that can reduce manufacturing costs through advantages such as high throughput, high material utilization, and low capital expenses. The film microstructure and grain size affects the solar cell performance. To realize low cost commercial production and high efficiencies of CZTSSe-based solar cells, it is necessary to understand the fundamental factors that affect crystal growth and microstructure evolution during CZTSSe annealing. Cu2ZnSnS4 (CZTS) nanocrystals were synthesized via thermolysis of single-source cation and sulfur precursors copper, zinc and tin diethyldithiocarbamates. The average nanocrystal size could be tuned between 2 nm and 40 nm, by varying the synthesis temperature between 150 °C and 340 °C. The synthesis is rapid and is completed in less than 10 minutes. Characterization by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy confirm that the nanocrystals are nominally

  7. Hydrothermal processes in partially serpentinized peridotites from Costa Rica: evidence from native copper and complex sulfide assemblages

    Science.gov (United States)

    Schwarzenbach, Esther M.; Gazel, Esteban; Caddick, Mark J.

    2014-11-01

    Native metals and metal alloys are common in serpentinized ultramafic rocks, generally representing the redox and sulfur conditions during serpentinization. Variably serpentinized peridotites from the Santa Elena Ophiolite in Costa Rica contain an unusual assemblage of Cu-bearing sulfides and native copper. The opaque mineral assemblage consists of pentlandite, magnetite, awaruite, pyrrhotite, heazlewoodite, violarite, smythite and copper-bearing sulfides (Cu-pentlandite, sugakiite [Cu(Fe,Ni)8S8], samaniite [Cu2(Fe,Ni)7S8], chalcopyrite, chalcocite, bornite and cubanite), native copper and copper-iron-nickel alloys. Using detailed mineralogical examination, electron microprobe analyses, bulk rock major and trace element geochemistry, and thermodynamic calculations, we discuss two models to explain the formation of the Cu-bearing mineral assemblages: (1) they formed through desulfurization of primary sulfides due to highly reducing and sulfur-depleted conditions during serpentinization or (2) they formed through interaction with a Cu-bearing, higher temperature fluid (350-400 °C) postdating serpentinization, similar to processes in active high-temperature peridotite-hosted hydrothermal systems such as Rainbow and Logatchev. As mass balance calculations cannot entirely explain the extent of the native copper by desulfurization of primary sulfides, we propose that the native copper and Cu sulfides formed by local addition of a hydrothermal fluid that likely interacted with adjacent mafic sequences. We suggest that the peridotites today exposed on Santa Elena preserve the lower section of an ancient hydrothermal system, where conditions were highly reducing and water-rock ratios very low. Thus, the preserved mineral textures and assemblages give a unique insight into hydrothermal processes occurring at depth in peridotite-hosted hydrothermal systems.

  8. Microbial Ecology Assessment of Mixed Copper Oxide/Sulfide Dump Leach Operation

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, Debby Fox; Thompson, David Neal; Noah, Karl Scott

    1999-06-01

    Microbial consortia composed of complex mixtures of autotrophic and heterotrophic bacteria are responsible for the dissolution of metals from sulfide minerals. Thus, an efficient copper bioleaching operation depends on the microbial ecology of the system. A microbial ecology study of a mixed oxide/sulfide copper leaching operation was conducted using an "overlay" plating technique to differentiate and identify various bacterial consortium members of the genera Thiobacillus, “Leptospirillum”, “Ferromicrobium”, and Acidiphilium. Two temperatures (30°C and 45°C) were used to select for mesophilic and moderately thermophilic bacteria. Cell numbers varied from 0-106 cells/g dry ore, depending on the sample location and depth. After acid curing for oxide leaching, no viable bacteria were recovered, although inoculation of cells from raffinate re-established a microbial population after three months. Due to low the pH of the operation, very few non-iron-oxidizing acidophilic heterotrophs were recovered. Moderate thermophiles were isolated from the ore samples. Pregnant liquor solutions (PLS) and raffinate both contained a diversity of bacteria. In addition, an intermittently applied waste stream that contained high levels of arsenic and fluoride was tested for toxicity. Twenty vol% waste stream in PLS killed 100% of the cells in 48 hours, indicating substantial toxicity and/or growth inhibition. The data indicate that bacteria populations can recover after acid curing, and that application of the waste stream to the dump should be avoided. Monitoring the microbial ecology of the leaching operation provided significant information that improved copper recovery.

  9. Space Charge Behavior in Paper Insulation Induced by Copper Sulfide in High-Voltage Direct Current Power Transformers

    Directory of Open Access Journals (Sweden)

    Ruijin Liao

    2015-08-01

    Full Text Available The main insulation system in high-voltage direct current (HVDC transformer consists of oil-paper insulation. The formation of space charge in insulation paper is crucial for the dielectric strength. Unfortunately, space charge behavior changes because of the corrosive sulfur substance in oil. This paper presents the space charge behavior in insulation paper induced by copper sulfide generated by corrosive sulfur in insulation oil. Thermal aging tests of paper-wrapped copper strip called the pigtail model were conducted at 130 °C in laboratory. Scanning electron microscopy (SEM was used to observe the surface of copper and paper. Pulse electroacoustic (PEA and thermally stimulated current (TSC methods were used to obtain the space charge behavior in paper. Results showed that both maximum and total amount of space charge increased for the insulation paper contaminated by semi-conductor chemical substance copper sulfide. The space charge decay rate of contaminated paper was significantly enhanced after the polarization voltage was removed. The TSC results revealed that copper sulfide increased the trap density and lowered the shallow trap energy levels. These results contributed to charge transportation by de-trapping and trapping processes. This improved charge transportation could be the main reason for the decreased breakdown voltage of paper insulation material.

  10. Synthesis of copper and zinc sulfide nanocrystals via thermolysis of the polymetallic thiolate cage

    Directory of Open Access Journals (Sweden)

    Toshihiro Kuzuya, Yutaka Tai, Saeki Yamamuro and Kenji Sumiyama

    2005-01-01

    Full Text Available In this paper report on the synthesis of copper and zinc sulfide nanocrystals (NCs via the formation of polymetallic thiolate cages. Cu2S NCs derived from Cu–dodecanethiol complex formed well-defined spherers, which were sufficiently monodisperse (with a size distribution of ~10% standard deviation of approximately 4.7 nm diameter on average to generate ordered self-assemblies. An electron diffraction pattern and UV–vis spectrum of Cu2S NCs indicate that this process can provide pure β-chalcocite (Cu2S. Nearly monodisperse ZnS NCs with a size ranging from 3 to 7 nm were obtained by thermolysis of the S–Zn–dodecanethiol precursor. The electron diffraction pattern indicates that zinc sulfide NCs are either wurtzite or a mixture of wurtzite and zincblende. TEM observation and UV–vis spectra revealed that the growth rate of ZnS NCs depends strongly on the annealing temperature. UV–vis spectra of 3 nm ZnS NCs show sharp excitonic features and a large blue shift from the bulk material. The photoluminescence spectra exhibit a large red shift from the absorption band edges. These shifts could be attributed to recombination from the surface traps. The narrow size distribution of Cu2S and ZnS NCs led to the formation of ordered self-assemblies with various well-defined but nonclosed-packing.

  11. Synthesis of Copper-Antimony-Sulfide Nanocrystals for Solution-Processed Solar Cells.

    Science.gov (United States)

    Suehiro, Satoshi; Horita, Keisuke; Yuasa, Masayoshi; Tanaka, Tooru; Fujita, Katsuhiko; Ishiwata, Yoichi; Shimanoe, Kengo; Kida, Tetsuya

    2015-08-17

    The p-type nanocrystals (NCs) of copper-based chalcogenides, such as CuInSe2 and Cu2ZnSnS4, have attracted increasing attention in photovoltaic applications due to their potential to produce cheap solution-processed solar cells. Herein, we report the synthesis of copper-antimony-sulfide (CAS) NCs with different crystal phases including CuSbS2, Cu3SbS4, and Cu12Sb4S13. In addition, their morphology, crystal phase, and optical properties were characterized using transmission electron microscopy, X-ray diffractometry, UV-vis-near-IR spectroscopy, and photoemission yield spectroscopy. The morphology, crystal phase, and electronic structure were significantly dependent on the chemical composition in the CAS system. Devices were fabricated using particulate films consisting of CAS NCs prepared by spin coating without a high-temperature treatment. The CAS NC-based devices exhibited a diode-like current-voltage characteristic when coupled with an n-type CdS layer. In particular, the CuSbS2 NC devices exhibited photovoltaic responses under simulated sunlight, demonstrating its applicability for use in solution-processed solar cells.

  12. Synthesis, Optical and Structural Properties of Copper Sulfide Nanocrystals from Single Molecule Precursors

    Directory of Open Access Journals (Sweden)

    Peter A. Ajibade

    2017-02-01

    Full Text Available We report the synthesis and structural studies of copper sulfide nanocrystals from copper (II dithiocarbamate single molecule precursors. The precursors were thermolysed in hexadecylamine (HDA to prepare HDA-capped CuS nanocrystals. The optical properties of the nanocrystals studied using UV–visible and photoluminescence spectroscopy showed absorption band edges at 287 nm that are blue shifted, and the photoluminescence spectra show emission curves that are red-shifted with respect to the absorption band edges. These shifts are as a result of the small crystallite sizes of the nanoparticles leading to quantum size effects. The structural studies were carried out using powder X-ray diffraction (XRD, transmission electron microscopy (TEM, scanning electron microscopy (SEM, energy dispersive X-ray spectroscopy (EDS, and atomic force microscopy. The XRD patterns indicates that the CuS nanocrystals are in hexagonal covellite crystalline phases with estimated particles sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes, with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microspheres on the surfaces, and EDS spectra confirmed the presence of CuS nanoparticles.

  13. Manganese (II) Chelate Functionalized Copper Sulfide Nanoparticles for Efficient Magnetic Resonance/Photoacoustic Dual-Modal Imaging Guided Photothermal Therapy.

    Science.gov (United States)

    Liu, Renfa; Jing, Lijia; Peng, Dong; Li, Yong; Tian, Jie; Dai, Zhifei

    2015-01-01

    The integration of diagnostic and therapeutic functionalities into one nanoplatform shows great promise in cancer therapy. In this research, manganese (II) chelate functionalized copper sulfide nanoparticles were successfully prepared using a facile hydrothermal method. The obtained ultrasmall nanoparticles exhibit excellent photothermal effect and photoaoustic activity. Besides, the high loading content of Mn(II) chelates makes the nanoparticles attractive T1 contrast agent in magnetic resonance imaging (MRI). In vivo photoacoustic imaging (PAI) results showed that the nanoparticles could be efficiently accumulated in tumor site in 24 h after systematic administration, which was further validated by MRI tests. The subsequent photothermal therapy of cancer in vivo was achieved without inducing any observed side effects. Therefore, the copper sulfide nanoparticles functionalized with Mn(II) chelate hold great promise as a theranostic nanomedicine for MR/PA dual-modal imaging guided photothermal therapy of cancer.

  14. Formation of copper tin sulfide films by pulsed laser deposition at 248 and 355 nm

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Crovetto, Andrea; Canulescu, Stela;

    2016-01-01

    The influence of the laser wavelength on the deposition of copper tin sulfide (CTS) and SnS-rich CTS with a 248-nm KrF excimer laser (pulse length τ = 20 ns) and a 355-nm frequency-tripled Nd:YAG laser (τ = 6 ns) was investigated. A comparative study of the two UV wavelengths shows that the CTS...

  15. Formation of copper tin sulfide films by pulsed laser deposition at 248 and 355 nm

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Crovetto, Andrea; Canulescu, Stela

    2016-01-01

    The influence of the laser wavelength on the deposition of copper tin sulfide (CTS) and SnS-rich CTS with a 248-nm KrF excimer laser (pulse length τ = 20 ns) and a 355-nm frequency-tripled Nd:YAG laser (τ = 6 ns) was investigated. A comparative study of the two UV wavelengths shows that the CTS...

  16. Structural, chemical and optical properties of the polyethylene–copper sulfide composite thin films synthesized using polythionic acid as sulfur source

    Energy Technology Data Exchange (ETDEWEB)

    Ancutiene, Ingrida [Department of Physical and Inorganic Chemistry, Kaunas University of Technology, Radvilenu st. 19, LT-50254 Kaunas (Lithuania); Navea, Juan G. [Chemistry Department, Skidmore College, 815N. Broadway, Saratoga Springs, NY 12866 (United States); Baltrusaitis, Jonas, E-mail: job314@lehigh.edu [Department of Chemical and Biomolecular Engineering, Lehigh University, B336 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 (United States)

    2015-08-30

    Graphical abstract: Several crystalline copper sulfide phases (spionkopite, anilite, digenite, djurleite, chalcocite) were obtained in as synthesized samples (PE-Cu{sub x}S) and elucidated using XRD. Thickness of the films obtained ranged from several microns to ∼18 μm and depended on the Cu(II/I) exposure time. Bandgap of the materials obtained was measured and ranged from 1.88 to 1.17 eV. Importantly, heating samples, many copper sulfide crystalline phase containing films at 100 °C in inert atmosphere invariably resulted in a single copper sulfide, anilite (Cu{sub 1.75}S), phase. - Highlights: • We investigated deposition of a single phase copper sulfide on polyethylene. • A single sulfur precursor – H{sub 2}S{sub 33}O{sub 6} – was used. • Increasing exposure time to Cu(II/I) yielded Cu{sub x}S with higher x values. • Heating at 100 °C in N{sub 2} resulted in a single anilite (Cu{sub 1.75}S) phase. • Cu(I) and Cu(II) compounds were detected using XPS. - Abstract: Synthesis and properties of thin copper sulfide films deposited on polyethylene were explored for the development of low cost hybrid organic–inorganic photovoltaic materials. Polyethylene was used as a model organic host material for thin copper sulfide film formation. Adsorption–diffusion method was used which utilized consecutive exposure of polyethylene to polythionic acid followed by aqueous Cu(II/I) solution. Several crystalline copper sulfide phases were obtained in synthesized samples and elucidated using X-ray diffraction. Surface chemical composition determined using X-ray photoelectron spectroscopy showed the presence of copper sulfides in combination with copper hydroxide. Thickness of the composite material films ranged from several microns to ∼18 μm and depended on the Cu(II/I) exposure time. Bandgap of the materials obtained was measured and ranged from 1.88 to 1.17 eV. Importantly, heating these complex copper sulfide crystalline phase containing films at 100

  17. Auger electron spectroscopic study of mechanism of sulfide-accelerated corrosion of copper-nickel alloy in seawater

    Science.gov (United States)

    Schrader, Malcolm E.

    The mechanism of sulfide-induced accelerated corrosion of 90-10 copper-nickel(iron) alloy is investigated. Samples of the alloy are exposed to flowing (2.4 m/s) seawater, with and without 0 01 mg/l sulfide, for various periods of time. The resulting surfaces are examined by means of Auger electron spectroscopy coupled with inert-ion-homoardment. A detailed depth profile is thereby obtained of concentrations in the surface region of a total of nine elements. The results are consistent with the hypothesis that iron hydroxide segregates at the surface to form a protective gelatinous layer against the normal chloride-induced corrosion process. Trace sulfide interferes with formation of a good protective layer and leaves the iron hydroxide vulnerable to ultimate partial or complete debonding. When the alloy is first exposed to "pure" seawater for a prolonged period of time, however, subsequent exposure to sulfide is no longer deleterious. This is apparently due to a layer of copper-nickel salt that slowly forms over the iron hydroxide.

  18. Sulfidation treatment of molten incineration fly ashes with Na2S for zinc, lead and copper resource recovery.

    Science.gov (United States)

    Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

    2007-04-01

    The present study focuses on the conversion of heavy metals involved in molten incineration fly ashes to metal sulfides which could be thereafter separated by flotation. The sulfidation treatment was carried out for five molten incineration fly ashes (Fly ash-A to Fly ash-E) by contacting each fly ash with Na(2)S solution for a period of 10 min to 6h. The initial molar ratio of S(2-) to Me(2+) was adjusted to 1.20. The conversion of heavy metals to metal sulfides was evaluated by measuring the S(2-) residual concentrations using an ion selective electrode. The formation of metal sulfides was studied by XRD and SEM-EDS analyses. In the case of Fly ash-A to Fly ash-D, more than 79% of heavy metals of zinc, lead and copper was converted to metal sulfides within the contacting period of 0.5h owing to a fast conversion of metal chlorides to metal sulfides. By contrast, the conversion of about 35% was achieved for Fly ash-E within the same contacting period, which was attributed to a high content of metal oxides. Further, the S(2-) to Me(2+) molar ratio was reduced to 1.00 to minimize Na(2)S consumption and the conversions obtained within the contacting period of 0.5h varied from 76% for Fly ash-D to 91% for Fly ash-C. Finally, soluble salts such as NaCl and KCl were removed during the sulfidation treatment, which brought about a significant enrichment in metals content by a factor varying from 1.5 for Fly ash-D to 4.9 for Fly ash-A.

  19. Tunable White Fluorescent Copper Gallium Sulfide Quantum Dots Enabled by Mn Doping.

    Science.gov (United States)

    Jo, Dae-Yeon; Kim, Daekyoung; Kim, Jong-Hoon; Chae, Heeyeop; Seo, Hyo Jin; Do, Young Rag; Yang, Heesun

    2016-05-18

    Fluorescence of semiconductor quantum dots (QDs) can be tuned by engineering the band gap via size and composition control and further doping them with impurity ions. Targeting on highly bright white-emissive I-III-VI -type copper gallium sulfide (Cu-Ga-S, CGS) host QDs with the entire visible spectral coverage of blue to red, herein, Mn(2+) ion doping, through surface adsorption and lattice diffusion is fulfilled. Upon doping a distinct Mn emission from (4)T1-(6)A1 transition successfully appears in white photoluminescence (PL) of undoped CGS/ZnS core/shell QDs and with varying Mn concentration a systematic white spectral evolution of CGS:Mn/ZnS QDs is achievable with high PL quantum yield retained. The origins of white PL of CGS:Mn/ZnS QDs that is well decomposed into three emission bands are appropriately assigned. The resulting single-phased, doped QDs are then employed as near-UV-to-white down converters for the fabrication of white light-emitting diodes (LEDs). Electroluminescent properties of white QD-LEDs depending on Mn concentration of CGS:Mn/ZnS QDs and forward current are also discussed in detail.

  20. Synthesis, characterization, shape evolution, and optical properties of copper sulfide hexagonal bifrustum nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Jia Baorui; Qin Mingli, E-mail: qinml@mater.ustb.edu.cn [University of Science and Technology Beijing, School of Materials Science and Engineering (China); Jiang Xuezhi [North Heavy Industry Group, Special Steel Works (China); Zhang Zili; Zhang Lin; Liu Ye; Qu Xuanhui [University of Science and Technology Beijing, School of Materials Science and Engineering (China)

    2013-03-15

    The hexagonal bifrustum-shaped copper sulfide (CuS) nanocrystals were selectively and facilely synthesized by a hydrothermal method for the first time at 120 Degree-Sign C. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, ultraviolet-visible (UV-Vis) spectroscopy, and photoluminescence spectroscopy. The results showed that the CuS hexagonal bifrustum nanocrystal was bounded by two top hexagons with edge length of about 50-70 nm and twelve lateral trapezoids with a base of about 100 nm and that the length of each hexagonal bifrustum was about 250 nm. Tetradecylamine (TDA), as an effective capping agent, was found to be critical for this special shape. Using different amounts of TDA, two kinds of CuS hexagonal bifrustum nanocrystals were obtained: 'lender hexagonal bifrustum' and 'pancake hexagonal bifrustum.' Furthermore, we studied the formation mechanism of hexagonal bifrustum, which is related to the intrinsic crystalline structure of CuS and Ostwald ripening. And, the results revealed that the CuS nanocrystal evolved from hexagonal plate to hexagonal bifrustum and finally to hexagonal bipyramid as the heating time increased. The UV-Vis absorption spectrum showed that these CuS hexagonal bifrustum nanocrystals exhibited strong absorption in the near-infrared region and had a potential application for photothermal therapy and photocatalysis.

  1. Extracellular biosynthesis of copper sulfide nanoparticles by Shewanella oneidensis MR-1 as a photothermal agent.

    Science.gov (United States)

    Zhou, Nan-Qing; Tian, Li-Jiao; Wang, Yu-Cai; Li, Dao-Bo; Li, Pan-Pan; Zhang, Xing; Yu, Han-Qing

    2016-12-01

    Photothermal therapy (PTT) is a minimally invasive and effective cancer treatment method and has a great potential for innovating the conventional chemotherapy approaches. Copper sulfide (CuS) exhibits photostability, low cost, and high absorption in near infrared region, and is recognized as an ideal candidate for PTT. However, CuS, as a photothermal agent, is usually synthesized with traditional chemical approaches, which require high temperature, additional stabilization and hydrophilic modification. Herein, we report, for the first time, the preparation of CuS nanoparticles as a photothermal agent by a dissimilatory metal reducing bacterium Shewanella. oneidensis MR-1. The prepared nanoparticles are homogenously shaped, hydrophilic, small-sized (∼5nm) and highly stable. Furthermore, the biosynthesized CuS nanoparticles display a high photothermal conversion efficiency of 27.2% because of their strong absorption at 1100nm. The CuS nanoparticles could be effectively used as a PTT agent under the irradiation of 1064nm. This work provides a simple, eco-friendly and cost-effective approach for fabricating PTT agents. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Synthesis and biomedical applications of copper sulfide nanoparticles: from sensors to theranostics.

    Science.gov (United States)

    Goel, Shreya; Chen, Feng; Cai, Weibo

    2014-02-26

    Copper sulfide (CuS) nanoparticles have attracted increasing attention from biomedical researchers across the globe, because of their intriguing properties which have been mainly explored for energy- and catalysis-related applications to date. This focused review article aims to summarize the recent progress made in the synthesis and biomedical applications of various CuS nanoparticles. After a brief introduction to CuS nanoparticles in the first section, we will provide a concise outline of the various synthetic routes to obtain different morphologies of CuS nanoparticles, which can influence their properties and potential applications. CuS nanoparticles have found broad applications in vitro, especially in the detection of biomolecules, chemicals, and pathogens which will be illustrated in detail. The in vivo uses of CuS nanoparticles have also been investigated in preclinical studies, including molecular imaging with various techniques, cancer therapy based on the photothermal properties of CuS, as well as drug delivery and theranostic applications. Research on CuS nanoparticles will continue to thrive over the next decade, and tremendous opportunities lie ahead for potential biomedical/clinical applications of CuS nanoparticles. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Copper zinc tin sulfide layers prepared from solution processable metal dithiocarbamate precursors

    Energy Technology Data Exchange (ETDEWEB)

    Edler, Michael [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Rath, Thomas, E-mail: thomas.rath@tugraz.at [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Schenk, Alexander [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Fischereder, Achim [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz (Austria); Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Haas, Wernfried [Christian Doppler Laboratory for Nanocomposite Solar Cells, Graz University of Technology and NanoTecCenter Weiz, Forschungsgesellschaft mbH (Austria); Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Edler, Matthias [Chair of Chemistry of Polymeric Materials, University of Leoben, Otto Gloeckel-Strasse 2, 8700 Leoben (Austria); Chernev, Boril [Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Kunert, Birgit [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Hofer, Ferdinand [Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); and others

    2012-10-15

    In this contribution we present a solution based route toward copper zinc tin sulfide - CZTS - layers using metal dithiocarbamate precursors. We focus on the synthesis of the precursor materials as well as on the fabrication of thin CZTS layers at low temperatures of 350 Degree-Sign C and their characterization. Powder X-ray diffraction measurements show that a precursor solution containing an excess of the zinc precursor, compared to the Cu and Sn precursors, has to be used to obtain CZTS films without secondary phases. Thus, the prepared films are Zn-rich, which is beneficial for solar cell applications. Raman as well as X-ray photoelectron spectroscopy studies confirm the formation of CTZS. No clear evidence for free ZnS has been found. Electron microscopy shows agglomerates of 10 nm-sized crystallites forming spherical particles with a diameter between 50 nm and 400 nm. The prepared films possess high optical absorption (>1.10{sup 4} cm{sup -1}) and an optical band gap of approximately 1.6 eV. Highlights: Black-Right-Pointing-Pointer CZTS layers are prepared from metal dithiocarbamate precursor solu-tions. Black-Right-Pointing-Pointer No additional sulfur sources or capping agents are necessary. Black-Right-Pointing-Pointer Prepared CZTS layers are zinc rich. Black-Right-Pointing-Pointer CZTS layers show a high absorption coefficient and a band gap of 1.6 eV.

  4. Size Dependence of Doping by a Vacancy Formation Reaction in Copper Sulfide Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Elimelech, Orian [The Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904 Israel; Liu, Jing [Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook NY 11794 USA; Plonka, Anna M. [Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook NY 11794 USA; Frenkel, Anatoly I. [Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook NY 11794 USA; Banin, Uri [The Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904 Israel

    2017-07-19

    Doping of nanocrystals (NCs) is a key, yet underexplored, approach for tuning of the electronic properties of semiconductors. An important route for doping of NCs is by vacancy formation. The size and concentration dependence of doping was studied in copper(I) sulfide (Cu2S) NCs through a redox reaction with iodine molecules (I2), which formed vacancies accompanied by a localized surface plasmon response. X-ray spectroscopy and diffraction reveal transformation from Cu2S to Cu-depleted phases, along with CuI formation. Greater reaction efficiency was observed for larger NCs. This behavior is attributed to interplay of the vacancy formation energy, which decreases for smaller sized NCs, and the growth of CuI on the NC surface, which is favored on well-defined facets of larger NCs. This doping process allows tuning of the plasmonic properties of a semiconductor across a wide range of plasmonic frequencies by varying the size of NCs and the concentration of iodine. Controlled vacancy doping of NCs may be used to tune and tailor semiconductors for use in optoelectronic applications.

  5. Rapid preparation of polonium counting sources for alpha spectrometry using copper sulfide microprecipitation.

    Science.gov (United States)

    Guérin, Nicolas; Dai, Xiongxin

    2013-07-02

    Thin-layer polonium (Po) sources for alpha spectrometry counting can be rapidly prepared using copper sulfide (CuS) microprecipitation. Polonium was coprecipitated with CuS, filtered onto Eichrom Resolve filters, and counted. This simple procedure is faster, cheaper, and more convenient than traditional spontaneous plating on metallic discs, and similar yields were obtained (80-90%). The experimental conditions for the microprecipitation technique were optimized (0.05 mg of Cu(2+) in 10 mL of 1 M HCl); these compare advantageously with conventional preparation and purification procedures for polonium samples (0.1 to 1 M HCl). The results showed that the most likely potential radionuclide interferences (Ra, Th, U, Np, Pu, and Am) for long-lived polonium isotopes ((208)Po, (209)Po, (210)Po) are effectively removed during processing. The effects of several transition metals (Cu(2+), Ag(+), Fe(3+), Fe(2+), Pb(2+), and Ni(2+)) on the yield and the resolution of the alpha peaks obtained were also assessed. Little interference was found, demonstrating the versatility of the present microprecipitation technique for environmental and biological matrices. The procedure has been successfully applied to different amounts of (210)Po using (209)Po as a yield tracer.

  6. Hydrogen Sulfide Promotes Wheat Seed Germination and Alleviates Oxidative Damage against Copper Stress

    Institute of Scientific and Technical Information of China (English)

    Hua Zhang; Lan-Ying Hu; Kang-Di Hu; Yun-Dong He; Song-Hua Wang; Jian-Ping Luo

    2008-01-01

    With the enhancement of copper (Cu) stress, the germination percentage of wheat seeds decreased gradually. Pretreatment with sodium hydrosulfide (NaHS), hydrogen sulfide (H2S) donor alleviated the inhibitory effect of Cu stress in a dose-dependent manner; whereas little visible symptom was observed in germinating seeds and radicle tips cultured in NaHs solutions. It was verified that H2S or HS- rather than other sulfur-containing components derived from NaHs attribute to the potential role in promoting seed germination against Cu stress. Further studies showed that NaHS could promote amylase and esterase activities, reduce Cu-induced disturbance of plasma membrane integrity in the radicle tips, and sustain lower levels of malondialdehyde and H2O2 in germinating seeds. Furthermore, NaHs pretreatment increased activities of superoxide dismutase and catalase and decreased that of lipoxygenase, but showed no significant effect on ascorbate peroxidase. Alternatively, NaHs prevented uptake of Cu and promoted the accumulation of free amino acids in seeds exposed to Cu. In addition, a rapid accumulation of endogenous H2S in seeds was observed at the early stags of germination, and higher level of H2S in NaHS-pretreated seeds. These data indicated that H2S was involved in the mechanism of germinating seeds' responses to Cu stress.

  7. Chlorin e6 conjugated copper sulfide nanoparticles for photodynamic combined photothermal therapy.

    Science.gov (United States)

    Bharathiraja, Subramaniyan; Manivasagan, Panchanathan; Moorthy, Madhappan Santha; Bui, Nhat Quang; Lee, Kang Dae; Oh, Junghwan

    2017-09-01

    The photo-based therapeutic approaches have attracted tremendous attention in recent years especially in treatment and management of tumors. Photodynamic and photothermal are two major therapeutic modalities which are being applied in clinical therapy. The development of nanomaterials for photodynamic combined with photothermal therapy has gained significant attention for its treatment efficacy. In the present study, we designed chlorin e6 (Ce6) conjugated copper sulfide (CuS) nanoparticles (CuS-Ce6 NPs) through amine functionalization and the synthesized nanoparticles act as a dual-model agent for photodynamic therapy and photothermal therapy. CuS-Ce6 NPs showed enhanced photodynamic effect through generation of singlet oxygen upon 670nm laser illumination. The same nanoparticles exerted thermal response under an 808nm laser at 2W/cm(2). The fabricated nanoparticles did not show any cytotoxic effect toward breast cancer cells in the absence of light. In vitro cell viability assay showed a potent cytotoxicity in photothermal and photodynamic treatment. Rather than singular treatment, the photodynamic combined photothermal treatment showed an enhanced cytotoxic effect on treated cells. In addition, the CuS-Ce6 NPs exert a photoacoustic signal for non-invasive imaging of treated cells in tissue-mimicking phantom. In conclusion the CuS-Ce6 NPs act as multimodal agent for photo based imaging and therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A pyrazolyl-based thiolato single-source precursor for the selective synthesis of isotropic copper-deficient copper(I) sulfide nanocrystals: synthesis, optical and photocatalytic activity

    Science.gov (United States)

    Mondal, Gopinath; Santra, Ananyakumari; Bera, Pradip; Acharjya, Moumita; Jana, Sumanta; Chattopadhyay, Dipankar; Mondal, Anup; Seok, Sang Il; Bera, Pulakesh

    2016-10-01

    Hexagonal copper-deficient copper(I) sulfide (Cu2- x S, x = 0.03, 0.2) nanocrystals (NCs) are synthesized from a newly prepared single-source precursor (SP), [Cu(bdpa)2][CuCl2], where bdpa is benzyl 3,5-dimethyl-pyrazole-1-carbodithioate. The SP is crystallized with space group Pī and possesses a distorted tetrahedron structure with a CuN2S2 chromophore where the central copper is in +1 oxidation state. Distortion in copper(I) structure and the low decomposition temperature of SP make it favorable for the low-temperature solvent-assisted selective growth of high-copper content sulfides. The nucleation and growth of Cu2- x S ( x = 0.03, 0.2) are effectively controlled by the SP and the solvent in the solvothermal decomposition process. During decomposition, fragment benzyl thiol (PhCH2SH) from SP effectively passivates the nucleus leading to spherical nanocrystals. Further, solvent plays an important role in the selective thermochemical transformation of CuI-complex to Cu2- x S ( x = 0.03, 0.2) NCs. The chelating binders (solvent) like ethylene diamine (EN) and ethylene glycol (EG) prefer to form spherical Cu1.97S nanoparticles (djurleite), whereas nonchelating hydrazine hydrate (HH) shows the tendency to furnish hexagonal platelets of copper-deficient Cu1.8S. The optical band gap values (2.25-2.50 eV) show quantum confinement effect in the structure. The synthesized NCs display excellent catalytic activity ( 87 %) toward photodegradation of organic dyes like Congo Red (CR) and Methylene Blue (MB).

  9. Reaction Mechanisms of Metals with Hydrogen Sulfide and Thiols in Model Wine. Part 1: Copper-Catalyzed Oxidation.

    Science.gov (United States)

    Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

    2016-05-25

    Sulfidic off-odors as a result of hydrogen sulfide (H2S) and low-molecular-weight thiols are commonly encountered in wine production. These odors are usually removed by the process of Cu(II) fining, a process that remains poorly understood. The present study aims to elucidate the underlying mechanisms by which Cu(II) interacts with H2S and thiol compounds (RSH) under wine-like conditions. Copper complex formation was monitored along with H2S, thiol, oxygen, and acetaldehyde concentrations after the addition of Cu(II) (50 or 100 μM) to air-saturated model wine solutions containing H2S, cysteine, 6-sulfanylhexan-1-ol, or 3-sulfanylhexan-1-ol (300 μM each). The presence of H2S and thiols in excess to Cu(II) led to the rapid formation of ∼1.4:1 H2S/Cu and ∼2:1 thiol/Cu complexes, resulting in the oxidation of H2S and thiols and reduction of Cu(II) to Cu(I), which reacted with oxygen. H2S was observed to initially oxidize rather than form insoluble copper sulfide. The proposed reaction mechanisms provide insight into the extent to which H2S can be selectively removed in the presence of thiols in wine.

  10. Novel Microbial Assemblages Dominate Weathered Sulfide-Bearing Rock from Copper-Nickel Deposits in the Duluth Complex, Minnesota, USA.

    Science.gov (United States)

    Jones, Daniel S; Lapakko, Kim A; Wenz, Zachary J; Olson, Michael C; Roepke, Elizabeth W; Sadowsky, Michael J; Novak, Paige J; Bailey, Jake V

    2017-08-15

    The Duluth Complex in northeastern Minnesota hosts economically significant deposits of copper, nickel, and platinum group elements (PGEs). The primary sulfide mineralogy of these deposits includes the minerals pyrrhotite, chalcopyrite, pentlandite, and cubanite, and weathering experiments show that most sulfide-bearing rock from the Duluth Complex generates moderately acidic leachate (pH 4 to 6). Microorganisms are important catalysts for metal sulfide oxidation and could influence the quality of water from mines in the Duluth Complex. Nevertheless, compared with that of extremely acidic environments, much less is known about the microbial ecology of moderately acidic sulfide-bearing mine waste, and so existing information may have little relevance to those microorganisms catalyzing oxidation reactions in the Duluth Complex. Here, we characterized the microbial communities in decade-long weathering experiments (kinetic tests) conducted on crushed rock and tailings from the Duluth Complex. Analyses of 16S rRNA genes and transcripts showed that differences among microbial communities correspond to pH, rock type, and experimental treatment. Moreover, microbial communities from the weathered Duluth Complex rock were dominated by taxa that are not typically associated with acidic mine waste. The most abundant operational taxonomic units (OTUs) were from the genera Meiothermus and Sulfuriferula, as well as from diverse clades of uncultivated Chloroflexi, Acidobacteria, and Betaproteobacteria Specific taxa, including putative sulfur-oxidizing Sulfuriferula spp., appeared to be primarily associated with Duluth Complex rock, but not pyrite-bearing rocks subjected to the same experimental treatment. We discuss the implications of these results for the microbial ecology of moderately acidic mine waste with low sulfide content, as well as for kinetic testing of mine waste.IMPORTANCE Economic sulfide mineral deposits in the Duluth Complex may represent the largest undeveloped

  11. Cherts from the Yangla copper deposit, western Yunnan Province: geochemical characteristics and relationship with massive sulfide mineralization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Four layers of cherts were found for the first time in the Yanglacopper deposit, western Yunnan Province. The cherts possessed the following geochemical characteristics: ① Low TiO2 and Al2O3 contents, but high ore-forming element (e.g. Cu, Au, Ag) contents; ② low total REE contents and clear negative Eu anomalies when normalized to chondrite similar to the REE contents and distribution patterns of associated massive sulfide ores; ③ silicon isotopic compositions of cherts in the Yangla deposit being the same as cherts and geyserite of hot-water sedimentary origin; ④ lead and sulfur isotopic compositions of cherts in the Yangla deposit being similar to those of the massive sulfide ores in the Yangla deposit; ⑤ Rb-Sr isochron age of cherts from the Yangla deposit being identical with that of host strata. Hence, we conclude that the cherts in the Yangla deposit are of hot-water sedimentary origin, which have a close relationship with the massive sulfide ores. The discovery of hydrothermal cherts from the Yangla copper deposit provides further evidence for the hydrothermal exhalative origin of the massive sulfide deposits.

  12. Enhanced reactive adsorption of hydrogen sulfide on the composites of graphene/graphite oxide with copper (hydr)oxychlorides.

    Science.gov (United States)

    Mabayoje, Oluwaniyi; Seredych, Mykola; Bandosz, Teresa J

    2012-06-27

    Composites of copper (hydr)oxychlorides with graphite oxide or graphene were synthesized and used as adsorbents of hydrogen sulfide at dynamic conditions at ambient temperatures. The materials were extensively characterized before and after adsorption in order to link their performance to the surface features. X-ray diffraction, FTIR, thermal analysis, TEM, SEM/EDX, and adsorption of nitrogen were used. It was found that the composite with graphene has the most favorable surface features enhancing reactive adsorption of hydrogen sulfide. The presence of moisture in the H2S stream has a positive effect on the removal process owing to the dissociation process. H2S is retained on the surface via a direct replacement of OH groups and via acid-base reactions with the copper (hydr)oxide. Highly dispersed reduced copper species on the surface of the composite with graphene enhance activation of oxygen and cause formation of sulfites and sulfates. Higher conductivity of the graphene phase than that of graphite oxide helps in electron transfer in redox reactions.

  13. Formation of Hydrogen Sulfide in Wine: Interactions between Copper and Sulfur Dioxide

    Directory of Open Access Journals (Sweden)

    Marlize Z. Bekker

    2016-09-01

    Full Text Available The combined synergistic effects of copper (Cu2+ and sulfur dioxide (SO2 on the formation of hydrogen sulfide (H2S in Verdelho and Shiraz wine samples post-bottling was studied over a 12-month period. The combined treatment of Cu2+ and SO2 significantly increased H2S formation in Verdelho wines samples that were not previously treated with either Cu2+ or SO2. The formation of H2S produced through Cu2+ mediated reactions was likely either: (a directly through the interaction of SO2 with either Cu2+ or H2S; or (b indirectly through the interaction of SO2 with other wine matrix compounds. To gain better understanding of the mechanisms responsible for the significant increases in H2S concentration in the Verdelho samples, the interaction between Cu2+ and SO2 was studied in a model wine matrix with and without the presence of a representative thiol quenching compound (4-methylbenzoquinone, 4MBQ. In these model studies, the importance of naturally occurring wine compounds and wine additives, such as quinones, SO2, and metal ions, in modulating the formation of H2S post-bottling was demonstrated. When present in equimolar concentrations a 1:1 ratio of H2S- and SO2-catechol adducts were produced. At wine relevant concentrations, however, only SO2-adducts were produced, reinforcing that the competition reactions of sulfur nucleophiles, such as H2S and SO2, with wine matrix compounds play a critical role in modulating final H2S concentrations in wines.

  14. Formation of Hydrogen Sulfide in Wine: Interactions between Copper and Sulfur Dioxide.

    Science.gov (United States)

    Bekker, Marlize Z; Smith, Mark E; Smith, Paul A; Wilkes, Eric N

    2016-09-10

    The combined synergistic effects of copper (Cu(2+)) and sulfur dioxide (SO₂) on the formation of hydrogen sulfide (H₂S) in Verdelho and Shiraz wine samples post-bottling was studied over a 12-month period. The combined treatment of Cu(2+) and SO₂ significantly increased H₂S formation in Verdelho wines samples that were not previously treated with either Cu(2+) or SO₂. The formation of H₂S produced through Cu(2+) mediated reactions was likely either: (a) directly through the interaction of SO₂ with either Cu(2+) or H₂S; or (b) indirectly through the interaction of SO₂ with other wine matrix compounds. To gain better understanding of the mechanisms responsible for the significant increases in H₂S concentration in the Verdelho samples, the interaction between Cu(2+) and SO₂ was studied in a model wine matrix with and without the presence of a representative thiol quenching compound (4-methylbenzoquinone, 4MBQ). In these model studies, the importance of naturally occurring wine compounds and wine additives, such as quinones, SO₂, and metal ions, in modulating the formation of H₂S post-bottling was demonstrated. When present in equimolar concentrations a 1:1 ratio of H₂S- and SO₂-catechol adducts were produced. At wine relevant concentrations, however, only SO₂-adducts were produced, reinforcing that the competition reactions of sulfur nucleophiles, such as H₂S and SO₂, with wine matrix compounds play a critical role in modulating final H₂S concentrations in wines.

  15. Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

    Directory of Open Access Journals (Sweden)

    Priscilla Vasthi Quintana-Ramirez

    2014-09-01

    Full Text Available Copper sulfide is a promising p-type inorganic semiconductor for optoelectronic devices such as solar cells, due its small band gap energy and its electrical properties. In this work nanocrystalline copper sulfide (CuxS, with two stoichiometric ratios (x = 2, 1.8 was obtained by one-pot synthesis at 220, 230, 240 and 260 °C in an organic solvent and amorphous CuxS was obtained in aqueous solution. Nanoparticle-like nucleation centers are formed at lower temperatures (220 °C, mixtures of morphologies (nanorods, nanodisks and nanoprisms are seen at 230 and 240 °C, in which the nanodisks are predominant, while big hexagonal/prismatic crystals are obtained at 260 °C according to TEM results. A mixture of chalcocite and digenite phases was found at 230 and 240 °C, while a clear transition to a pure digenite phase was seen at 260 °C. The evolution of morphology and transition of phases is consistent to the electrical, optical, and morphological properties of the copper sulfide. In fact, digenite Cu1.8S is less resistive (346 Ω/sq and has a lower energy band gap (1.6 eV than chalcocite Cu2S (5.72 × 105 Ω/sq, 1.87 eV. Low resistivity was also obtained in CuxS synthesized in aqueous solution, despite its amorphous structure. All CuxS products could be promising for optoelectronic applications.

  16. Comprehensive Investigation of Silver Nanoparticle/Aluminum Electrodes for Copper Indium Sulfide/Polymer Hybrid Solar Cells

    DEFF Research Database (Denmark)

    Arar, Mario; Pein, Andreas; Haas, Wernfried

    2012-01-01

    Electrode materials are primarily chosen based on their work function to suit the energy levels of the absorber materials. In this paper, we focus on the modification of aluminum cathodes with a thin silver interlayer (2 nm) in copper indium sulfide/poly[(2,7-silafluorene)-alt-(4,7-di-2-thienyl-2...... nanoparticles in an aluminum oxide matrix between the absorber layer and the aluminum cathode. In combination with complementary optical investigations, the origin of the improvement is ascribed to a facilitated charge extraction....

  17. Intense pulsed light annealing of copper zinc tin sulfide nanocrystal coatings

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Bryce A.; Smeaton, Michelle A.; Holgate, Collin S.; Trejo, Nancy D.; Francis, Lorraine F., E-mail: francis@umn.edu; Aydil, Eray S., E-mail: aydil@umn.edu [Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Avenue SE, Minneapolis, Minnesota 55455 (United States)

    2016-09-15

    A promising method for forming the absorber layer in copper zinc tin sulfide [Cu{sub 2}ZnSnS{sub 4} (CZTS)] thin film solar cells is thermal annealing of coatings cast from dispersions of CZTS nanocrystals. Intense pulsed light (IPL) annealing utilizing xenon flash lamps is a potential high-throughput, low-cost, roll-to-roll manufacturing compatible alternative to thermal annealing in conventional furnaces. The authors studied the effects of flash energy density (3.9–11.6 J/cm{sup 2}) and number of flashes (1–400) during IPL annealing on the microstructure of CZTS nanocrystal coatings cast on molybdenum-coated soda lime glass substrates (Mo-coated SLG). The annealed coatings exhibited cracks with two distinct linear crack densities, 0.01 and 0.2 μm{sup −1}, depending on the flash intensity and total number of flashes. Low density cracking (0.01 μm{sup −1}, ∼1 crack per 100 μm) is caused by decomposition of CZTS at the Mo-coating interface. Vapor decomposition products at the interface cause blisters as they escape the coating. Residual decomposition products within the blisters were imaged using confocal Raman spectroscopy. In support of this hypothesis, replacing the Mo-coated SLG substrate with quartz eliminated blistering and low-density cracking. High density cracking is caused by rapid thermal expansion and contraction of the coating constricted on the substrate as it is heated and cooled during IPL annealing. Finite element modeling showed that CZTS coatings on low thermal diffusivity materials (i.e., SLG) underwent significant differential heating with respect to the substrate with rapid rises and falls of the coating temperature as the flash is turned on and off, possibly causing a build-up of tensile stress within the coating prompting cracking. Use of a high thermal diffusivity substrate, such as a molybdenum foil (Mo foil), reduces this differential heating and eliminates the high-density cracking. IPL annealing in presence of sulfur

  18. High-performance reagent modes for flotation recovery of platiniferous copper and nickel sulfides from hard-to-beneficiate ores

    Science.gov (United States)

    Matveeva, T. N.; Chanturiya, V. A.

    2017-07-01

    The paper presents the results of the recent research performed in IPKON Russian Academy of Sciences that deals with development and substantiation of new selective reagents for effective flotation recovery of non-ferrous and noble metals from refractory ores. The choice and development of new selective reagents PTTC, OPDTC, modified butylxanthate (BXm) and modified diethyl-dithiocarbamate (DEDTCm) to float platiniferous copper and nickel sulfide minerals from hard-to-beneficiate ores is substantiated. The mechanism of reagents adsorption and regulation of minerals floatability is discussed. The study of reagent modes indicates that by combining PTTC with the modified xanthate results in 6 - 7 % increase in the recovery of copper, nickel and PGM in the flotation of the low-sulfide platiniferous Cu-Ni ore from the Fedorovo-Panskoye deposit. The substitution of OPDTC for BX makes it possible to increase recovery of Pt by 13 %, Pd by 9 % and 2 - 4 times the noble metal content in the flotation concentrate.

  19. Weathering of sulfidic shale and copper mine waste: Secondary minerals and metal cycling in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA

    Science.gov (United States)

    Hammarstrom, J.M.; Seal, R.R.; Meier, A.L.; Jackson, J.C.

    2003-01-01

    Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts on aquatic ecosystems are aluminum, copper, zinc, and arsenic because these elements locally exceed toxicity guidelines for surface waters or for stream sediments. Acid-mine drainage has not developed in streams draining inactive copper mines. Acid-rock drainage and chemical weathering processes that accompany debris flows or human disturbances of sulfidic rocks are comparable to processes that develop acid-mine drainage elsewhere. Despite the high rainfall in the mountain range, sheltered areas and intermittent dry spells provide local venues for development of secondary weathering products that can impact aquatic ecosystems.

  20. The 982 Ma Re-Os age of copper-nickel sulfide ores in the Baotan area, Guangxi and its geological significance

    Institute of Scientific and Technical Information of China (English)

    毛景文; 杜安道

    2002-01-01

    Re-Os dating on copper-nickel sulfide ores from the Baotan area, Guangxi, yielded an ore-forming age of 982±21 Ma(2σ), which demonstrates that copper-nickel sulfide deposits and their related mafic-ultramafic rocks occurred in the same period of time with the ophiolites in northeastern Jiangxi. Both of them are the products of collision-convergence between the Cathaysian plate and Yangtze plate and the subsequent extensional environment. Calculation of the γOs of the 982 Ma copper-nickel sulfide ores and its correlation with Re/Os indicate that injection-type massive ores display lower γOs values(-15.6 to -8.2) and lower Re/Os ratios(0.32 to 0.43), while basal liquation-type ores have γOs= -27.9 to -7.3 and Re/Os=5.36 to 11.24. This suggests that these copper-nickel sulfide ores and their related mafic-ultramafic rocks were derived from a Re-depleted mantle source and that contamination with some crustal material occurred during their intrusion.

  1. Development and functioning of microorganisms in concentration cycles of sulfide copper-nickel and non-sulfide apatite-nepheline ores

    Directory of Open Access Journals (Sweden)

    Fokina N. V.

    2017-03-01

    Full Text Available The number and trophic diversity of bacteria in flotation samples of apatite-nepheline and sulfide copper-nickel ores at the concentration plants of JSC "Apatite" and Kola Mining and Metallurgical Company have been determined. The study of the size and diversity of the microbiota has been conducted by culture on selective nutrient media. The total number and biomass of bacteria have been considered by fluorescence microscopy using Cyclopore polycarbonate membrane filters. Bacteria have been identified by molecular genetic methods. The least amount of both saprotrophic and other trophic groups of bacteria has been observed in the samples of ore and recycled water as at the concentrating factory of Apatit JSC, and also at the plant "Pechenganikel". It has been found out that the bacteria contained in the ore and recycling water flowing from the tailings increased their number during the flotation process due to coming of the nutrients with the flotation reagents, aeration and increased temperature. Strains which occurrence is more than 60 % have been extracted from recycled water and basic flotation products and classified as Pseudomonas. Two strains with occurrence of more than 60 % have been discovered at Apatit JSC and classified as Stenotrophomonas and Acinetobacter. The number of fungi in the cycle of apatite-nepheline ore enrichment at the factories is very low (1 to 24 CFU / 1 ml or 1 g of ore. Fungi of the genus Penicillium have been dominated, fungi of the genera Acremonium, Aureobasidium, Alternaria, Chaetomium have also been detected. At the plant "Pechenganikel" species Aspergillus fumigatus, Penicillium aurantiogriseum and P. glabrum have been extracted. It has been shown that the bacteria deteriorate the apatite flotation as a result of their interaction with active centers of calcium-containing minerals and intensive flocculation decreasing the floatation selectivity. Also some trend of copper and nickel recovery change has been

  2. Highly sensitive photodetectors based on hybrid 2D-0D SnS{sub 2}-copper indium sulfide quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yun; Zhan, Xueying; Xu, Kai; Yin, Lei; Cheng, Zhongzhou; Jiang, Chao; Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn; He, Jun, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn [CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China)

    2016-01-04

    Both high speed and efficiency of photoelectric conversion are essential for photodetectors. As an emerging layered metal dichalcogenide (LMD), tin disulfide owns intrinsic faster photodetection ability than most other LMDs but poor light absorption and low photoelectric conversion efficiency. We develop an efficient method to enhance its performance by constructing a SnS{sub 2}-copper indium sulfide hybrid structure. As a result, the responsivity reaches 630 A/W, six times stronger than pristine SnS{sub 2} and much higher than most other LMDs photodetectors. Additionally, the photocurrents are enhanced by more than 1 order of magnitude. Our work may open up a pathway to improve the performance of photodetectors based on LMDs.

  3. Size Dependence of a Temperature-Induced Solid-Solid Phase Transition in Copper(I) Sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Rivest, Jessy B; Fong, Lam-Kiu; Jain, Prashant K; Toney, Michael F; Alivisatos, A Paul

    2011-07-24

    Determination of the phase diagrams for the nanocrystalline forms of materials is crucial for our understanding of nanostructures and the design of functional materials using nanoscale building blocks. The ability to study such transformations in nanomaterials with controlled shape offers further insight into transition mechanisms and the influence of particular facets. Here we present an investigation of the size-dependent, temperature-induced solid-solid phase transition in copper sulfide nanorods from low- to high-chalcocite. We find the transition temperature to be substantially reduced, with the high chalcocite phase appearing in the smallest nanocrystals at temperatures so low that they are typical of photovoltaic operation. Size dependence in phase trans- formations suggests the possibility of accessing morphologies that are not found in bulk solids at ambient conditions. These other- wise-inaccessible crystal phases could enable higher-performing materials in a range of applications, including sensing, switching, lighting, and photovoltaics.

  4. Copper sulfide nanoparticle-decorated graphene as a catalytic amplification platform for electrochemical detection of alkaline phosphatase activity.

    Science.gov (United States)

    Peng, Juan; Han, Xiao-Xia; Zhang, Qing-Chun; Yao, Hui-Qin; Gao, Zuo-Ning

    2015-06-01

    Copper sulfide nanoparticle-decorated graphene sheet (CuS/GR) was successfully synthesized and used as a signal amplification platform for electrochemical detection of alkaline phosphatase activity. First, CuS/GR was prepared through a microwave-assisted hydrothermal approach. The CuS/GR nanocomposites exhibited excellent electrocatalytic activity toward the oxidation of ALP hydrolyzed products such as 1-naphthol, which produced a current response. Thus, a catalytic amplification platform based on CuS/GR nanocomposite for electrochemical detection of ALP activity was designed using 1-naphthyl phosphate as a model substrate. The current response increased linearly with ALP concentration from 0.1 to 100 U L(-1) with a detection limit of 0.02 U L(-1). The assay was applied to estimate ALP activity in human serum samples with satisfactory results. This strategy may find widespread and promising applications in other sensing systems that involves ALP.

  5. Occurrence model for magmatic sulfide-rich nickel-copper-(platinum-group element) deposits related to mafic and ultramafic dike-sill complexes: Chapter I in Mineral deposit models for resource assessment

    Science.gov (United States)

    Schulz, Klaus J.; Woodruff, Laurel G.; Nicholson, Suzanne W.; Seal, Robert R., II; Piatak, Nadine M.; Chandler, Val W.; Mars, John L.

    2014-01-01

    Magmatic sulfide deposits containing nickel (Ni) and copper (Cu), with or without (±) platinum-group elements (PGE), account for approximately 60 percent of the world’s nickel production. Most of the remainder of the Ni production is derived from lateritic deposits, which form by weathering of ultramafic rocks in humid tropical conditions. Magmatic Ni-Cu±PGE sulfide deposits are spatially and genetically related to bodies of mafic and/or ultramafic rocks. The sulfide deposits form when the mantle-derived mafic and/or ultramafic magmas become sulfide-saturated and segregate immiscible sulfide liquid, commonly following interaction with continental crustal rocks.

  6. The Effect of Desulfovibrio sp. Biofilms on Corrosion Behavior of Copper in Sulfide-Containing Solutions

    Science.gov (United States)

    Güngör, Nihal Doğruöz; Çotuk, Ayşın; Dışpınar, Derya

    2015-03-01

    This study aims to detect the effect of Desulfovibrio sp. on copper in terms of biofilm formation and corrosion in 722 h. In that way, appropriate strategies to inhibit microbiological corrosion in copper systems with Desulfovibrio sp. can be evaluated. For this purpose, experiments were performed in 1 L glass model system containing 28 copper coupons and pure culture of the sulfate-reducing bacteria (SRB) strain Desulfovibrio sp. in Postgate's medium C. Also, a control system with copper coupons but without Desulfovibrio sp. containing sterile Postgate's medium was studied concurrently with the test system. The test coupons were collected from systems at certain time intervals, namely 24, 168, 360, and 720 h. The samples were then subjected to several characterization analyses such as measurement of Desulfovibrio sp. numbers, corrosion resistance, EPS extraction, carbohydrate analysis, SEM, and EDS. During the experiments, the maximum Desulfovibrio sp. count in biofilm samples was found at 360 h. Carbohydrate and copper concentrations in biofilm were increased over time. EDS analysis revealed Cu, S, C, O, and Cl peaks on the surface of the samples. For the control coupons, only Cu peaks were observed. The results obtained from this study showed that copper was corroded by Desulfovibrio sp. in the model system under laboratory conditions.

  7. Scanning electrochemical microscopy studies of micropatterned copper sulfide (CuxS) thin films fabricated by a wet chemistry method

    Science.gov (United States)

    Chen, Miao; Zhao, Jing; Zhao, Xiaocui

    2011-01-01

    Patterned copper sulfide (CuxS) microstructures on Si (1 1 1) wafers were successfully fabricated by a relatively simple solution growth method using copper sulfate, ethylenediaminetetraacetate and sodium thiosulfate aqueous solutions as precursors. The CuxS particles were selectively deposited on a patterned self-assembled monolayer of 3-aminopropyltriethoxysilane regions created by photolithography. To obtain high quality CuxS films, preparative conditions such as concentration, proportion, pH and temperature of the precursor solutions were optimized. Various techniques such as optical microscopy, atomic force microscopy (AFM), X-ray diffraction, optical absorption and scanning electrochemical microscopy (SECM) were employed to examine the topography and properties of the micro-patterned CuxS films. Optical microscopy and AFM results indicated that the CuxS micro-pattern possessed high selectivity and clear edge resolution. From combined X-ray diffraction analysis and optical band gap calculations we conclude that Cu9S5 (digenite) was the main phase within the resultant CuxS film. Both SECM image and cyclic voltammograms confirmed that the CuxS film had good electrical conductivity. Moreover, from SECM approach curve analysis, the apparent electron-transfer rate constant (k) in the micro-pattern of CuxS dominated surface was estimated as 0.04 cm/s. The SECM current map showed high edge acuity of the micro-patterned CuxS. PMID:21785491

  8. Scanning electrochemical microscopy studies of micropatterned copper sulfide (Cu(x)S) thin films fabricated by a wet chemistry method.

    Science.gov (United States)

    Chen, Miao; Zhao, Jing; Zhao, Xiaocui

    2011-05-30

    Patterned copper sulfide (Cu(x)S) microstructures on Si (1 1 1) wafers were successfully fabricated by a relatively simple solution growth method using copper sulfate, ethylenediaminetetraacetate and sodium thiosulfate aqueous solutions as precursors. The Cu(x)S particles were selectively deposited on a patterned self-assembled monolayer of 3-aminopropyltriethoxysilane regions created by photolithography. To obtain high quality Cu(x)S films, preparative conditions such as concentration, proportion, pH and temperature of the precursor solutions were optimized. Various techniques such as optical microscopy, atomic force microscopy (AFM), X-ray diffraction, optical absorption and scanning electrochemical microscopy (SECM) were employed to examine the topography and properties of the micro-patterned Cu(x)S films. Optical microscopy and AFM results indicated that the Cu(x)S micro-pattern possessed high selectivity and clear edge resolution. From combined X-ray diffraction analysis and optical band gap calculations we conclude that Cu(9)S(5) (digenite) was the main phase within the resultant Cu(x)S film. Both SECM image and cyclic voltammograms confirmed that the Cu(x)S film had good electrical conductivity. Moreover, from SECM approach curve analysis, the apparent electron-transfer rate constant (k) in the micro-pattern of Cu(x)S dominated surface was estimated as 0.04 cm/s. The SECM current map showed high edge acuity of the micro-patterned Cu(x)S.

  9. Copper sulfide nanoparticles with phospholipid-PEG coating for in vivo near-infrared photothermal cancer therapy.

    Science.gov (United States)

    Huang, Yizhuan; Lai, Yulian; Shi, Saige; Hao, Shufang; Wei, Jingping; Chen, Xiaolan

    2015-02-01

    In this work, small sizes of hydrophobic copper sulfide nanoparticles (CuS NPs, ∼3.8 nm in diameter) have been successfully prepared from the reaction of copper chloride with sodium diethyldithiocarbamate (SDEDTC) inside a heated oleylamine solution. These CuS NPs displayed strong absorption in the 700-1100 nm near-infrared (NIR) region. By coating CuS NPs with DSPE-PEG2000 on the surface, the as-synthesized CuS@DSPE-PEG NPs exhibited good water solubility, significant stability and biocompatibility, as well as excellent photothermal conversion effects upon exposure to an 808 nm laser. After intravenous administration to mice, the CuS@DSPE-PEG NPs were found to passively target to the tumor site, and tumor tissues could be ablated efficiency under laser irradiation. In addition, CuS@DSPE-PEG NPs do not show significant toxicity by histological and blood chemistry analysis, and can be effectively excreted via metabolism. Our results indicated that CuS@DSPE-PEG NPs can act as an ideal photothermal agent for cancer photothermal therapy.

  10. Synthesis And Characterization of Copper Zinc Tin Sulfide Nanoparticles And Thin Films

    Science.gov (United States)

    Khare, Ankur

    Copper zinc tin sulfide (Cu2ZnSnS4, or CZTS) is emerging as an alternative material to the present thin film solar cell technologies such as Cu(In,Ga)Se2 and CdTe. All the elements in CZTS are abundant, environmentally benign, and inexpensive. In addition, CZTS has a band gap of ˜1.5 eV, the ideal value for converting the maximum amount of energy from the solar spectrum into electricity. CZTS has a high absorption coefficient (>104 cm-1 in the visible region of the electromagnetic spectrum) and only a few micron thick layer of CZTS can absorb all the photons with energies above its band gap. CZT(S,Se) solar cells have already reached power conversion efficiencies >10%. One of the ways to improve upon the CZTS power conversion efficiency is by using CZTS quantum dots as the photoactive material, which can potentially achieve efficiencies greater than the present thin film technologies at a fraction of the cost. However, two requirements for quantum-dot solar cells have yet to be demonstrated. First, no report has shown quantum confinement in CZTS nanocrystals. Second, the syntheses to date have not provided a range of nanocrystal sizes, which is necessary not only for fundamental studies but also for multijunction photovoltaic architectures. We resolved these two issues by demonstrating a simple synthesis of CZTS, Cu2SnS3, and alloyed (Cu2SnS3) x(ZnS)y nanocrystals with diameters ranging from 2 to 7 nm from diethyldithiocarbamate complexes. As-synthesized nanocrystals were characterized using high resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and energy dispersive spectroscopy to confirm their phase purity. Nanocrystals of diameter less than 5 nm were found to exhibit a shift in their optical absorption spectra towards higher energy consistent with quantum confinement and previous theoretical predictions. Thin films from CZTS nanocrystals deposited on Mo-coated quartz substrates using drop casting were found to be continuous

  11. Bis[(diphenylphosphanylmethyldiphenylphosphane sulfide-κ2P,S]copper(I hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    Jing-Jing Zhang

    2012-06-01

    Full Text Available In the title compound, [Cu(C25H22P2S2]PF6, the CuI atom, lying on a twofold rotation axis, adopts a distorted tetrahedral geometry. The (diphenylphosphanylmethyldiphenylphosphane sulfide ligand coordinates to the CuI atom through one S and one P atom, forming a stable five-membered chelate ring. The P atom of the PF6− anion also lies on a twofold rotation axis.

  12. In situ solvothermal growth of metal-organic framework-5 supported on porous copper foam for noninvasive sampling of plant volatile sulfides.

    Science.gov (United States)

    Hu, Yuling; Lian, Haixian; Zhou, Langjun; Li, Gongke

    2015-01-06

    The present study reported on an in situ solvothermal growth method for immobilization of metal-organic framework MOF-5 on porous copper foam support for enrichment of plant volatile sulfides. The porous copper support impregnated with mother liquor of MOF-5 anchors the nucleation and growth of MOF crystallites at its surface, and its architecture of the three-dimensional channel enables accommodation of the MOF-5 crystallite seed. A continuous and well-intergrown MOF-5 layer, evidenced from scanning electron microscope imaging and X-ray diffraction, was successfully immobilized on the porous metal bar with good adhesion and high stability. Results show that the resultant MOF-5 coating was thermally stable up to 420 °C and robust enough for replicate extraction for at least 200 times. The MOF-5 bar was then applied to the headspace sorptive extraction of the volatile organic sulfur compounds in Chinese chive and garlic sprout in combination with thermal desorption-gas chromatography/mass spectrometry. It showed high extraction sensitivity and good selectivity to these plant volatile sulfides owing to the extraordinary porosity of the metal-organic framework as well as the interaction between the S-donor sites and the surface cations at the crystal edges. Several primary sulfur volatiles containing allyl methyl sulfide, dimethyl disulfide, diallyl sulfide, methyl allyl disulfide, and diallyl disulfide were quantified. Their limits of detection were found to be in the range of 0.2-1.7 μg/L. The organic sulfides were detected in the range of 6.0-23.8 μg/g with recoveries of 76.6-100.2% in Chinese chive and 11.4-54.6 μg/g with recoveries of 77.1-99.8% in garlic sprout. The results indicate the immobilization of MOF-5 on copper foam provides an efficient enrichment formats for noninvasive sampling of plant volatiles.

  13. Iron sulfide attenuates the methanogenic toxicity of elemental copper and zinc oxide nanoparticles and their soluble metal ion analogs.

    Science.gov (United States)

    Gonzalez-Estrella, Jorge; Gallagher, Sara; Sierra-Alvarez, Reyes; Field, Jim A

    2016-04-01

    Elemental copper (Cu(0)) and zinc oxide (ZnO) nanoparticle (NP) toxicity to methanogens has been attributed to the release of soluble metal ions. Iron sulfide (FeS) partially controls the soluble concentration of heavy metals and their toxicity in aquatic environments. Heavy metals displace the Fe from FeS forming poorly soluble metal sulfides in the FeS matrix. Therefore, FeS may be expected to attenuate the NP toxicity. This work assessed FeS as an attenuator of the methanogenic toxicity of Cu(0) and ZnO NPs and their soluble salt analogs. The toxicity attenuation capacity of fine (25-75μm) and coarse (500 to 1200μm) preparations of FeS (FeS-f and FeS-c respectively) was tested in the presence of highly inhibitory concentrations of CuCl2, ZnCl2 Cu(0) and ZnO NPs. FeS-f attenuated methanogenic toxicity better than FeS-c. The results revealed that 2.5× less FeS-f than FeS-c was required to recover the methanogenic activity to 50% (activity normalized to uninhibited controls). The results also indicated that a molar FeS-f/Cu(0) NP, FeS-f/ZnO NP, FeS-f/ZnCl2, and FeS-f/CuCl2 ratio of 2.14, 2.14, 4.28, and 8.56 respectively, was necessary to recover the methanogenic activity to >75%. Displacement experiments demonstrated that CuCl2 and ZnCl2 partially displaced Fe from FeS. As a whole, the results indicate that not all the sulfide in FeS was readily available to react with the soluble Cu and Zn ions which may explain the need for a large stoichiometric excess of FeS to highly attenuate Cu and Zn toxicity. Overall, this study provides evidence that FeS attenuates the toxicity caused by Cu(0) and ZnO NPs and their soluble ion analogs to methanogens.

  14. Copper tin sulfide (CTS) absorber thin films obtained by co-evaporation: Influence of the ratio Cu/Sn

    Energy Technology Data Exchange (ETDEWEB)

    Robles, V., E-mail: victor.robles@ciemat.es; Trigo, J.F.; Guillén, C.; Herrero, J.

    2015-09-05

    Highlights: • Copper tin sulfide (CTS) thin films were grown by co-evaporation at different Cu/Sn atomic ratios. • Smooth Cu{sub 2}SnS{sub 3} layers with large grains are obtained at Cu/Sn ⩾ 1.5 and T ⩾ 350 °C. • At 450 °C, the cubic Cu{sub 2}SnS{sub 3} phase changes to tetragonal phase. • Cu{sub 2}SnS{sub 3} presents suitable optical and electrical properties for use as photovoltaic absorbers. - Abstract: Copper tin sulfide thin films have been grown on soda-lime glass substrates from the elemental constituents by co-evaporation. The synthesis was performed at substrate temperatures of 350 °C and 450 °C and different Cu/Sn ratios, adjusting the deposition time in order to obtain thicknesses above 1000 nm. The evolution of the morphological, structural, chemical, optical and electrical properties has been analyzed as a function of the substrate temperature and the Cu/Sn ratio. For the samples with Cu/Sn ⩽ 1, Cu{sub 2}Sn{sub 3}S{sub 7} and Cu{sub 2}SnS{sub 3} have been observed by XRD. Increasing the Cu/Sn to 1.5, the Cu{sub 2}SnS{sub 3} phase was the majority, being the formation completed at Cu/Sn ratio around 2. The increment of the substrate temperature leads to a change of cubic structure to tetragonal of the Cu{sub 2}SnS{sub 3} phase. The chemical treatment with KCN was effective to eliminate CuS excess detected in the samples with Cu/Sn > 2.2. The samples with Cu{sub 2}SnS{sub 3} structure show a band gap energy increasing from 0.9 to 1.25 eV and an electrical resistivity decreasing from 7 ∗ 10{sup −2} Ω cm to 3 ∗ 10{sup −3} Ω cm when the Cu/Sn atomic ratio increases from 1.5 to 2.2.

  15. Sonochemical method for preparation of copper indium sulfide nanoparticles and their application for solar cell.

    Science.gov (United States)

    Amiri, Omid; Salavati-Niasari, Masoud; Sabet, Mohammad; Ghanbari, Davood

    2014-02-01

    In this paper, CuInS2 (CIS) nanoparticles were synthesized successfully via a new copper precursor [bis(acetylacetonato)copper(II)], [Cu(acac)2]; at room temperature by ultrasonic method. The effect of sulfur source, solvent, and reaction time was investigated on product morphology and particle size. A series of analyses was performed to characterize the CuInS2 microsphere including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. CuInS2 nanoparticles were prepared and coated on FTO. Later, the coated FTO was sintered so that a compact and dense CuInS2 film was produced and measured for photovoltaic characteristics such as Voc, Jsc and FF.

  16. A review of the fundamental studies of the copper activation mechanisms for selective flotation of the sulfide minerals, sphalerite and pyrite.

    Science.gov (United States)

    Chandra, A P; Gerson, A R

    2009-01-30

    A review of the considerable, but often contradictory, literature examining the specific surface reactions associated with copper adsorption onto the common metal sulfide minerals sphalerite, (Zn,Fe)S, and pyrite (FeS(2)), and the effect of the co-location of the two minerals is presented. Copper "activation", involving the surface adsorption of copper species from solution onto mineral surfaces to activate the surface for hydrophobic collector attachment, is an important step in the flotation and separation of minerals in an ore. Due to the complexity of metal sulfide mineral containing systems this activation process and the emergence of activation products on the mineral surfaces are not fully understood for most sulfide minerals even after decades of research. Factors such as copper concentration, activation time, pH, surface charge, extent of pre-oxidation, water and surface contaminants, pulp potential and galvanic interactions are important factors affecting copper activation of sphalerite and pyrite. A high pH, the correct reagent concentration and activation time and a short time delay between reagent additions is favourable for separation of sphalerite from pyrite. Sufficient oxidation potential is also needed (through O(2) conditioning) to maintain effective galvanic interactions between sphalerite and pyrite. This ensures pyrite is sufficiently depressed while sphalerite floats. Good water quality with low concentrations of contaminant ions, such as Pb(2+)and Fe(2+), is also needed to limit inadvertent activation and flotation of pyrite into zinc concentrates. Selectivity can further be increased and reagent use minimised by opting for inert grinding and by carefully choosing selective pyrite depressants such as sulfoxy or cyanide reagents. Studies that approximate plant conditions are essential for the development of better separation techniques and methodologies. Improved experimental approaches and surface sensitive techniques with high spatial

  17. Magmatic sulfide-rich nickel-copper deposits related to picrite and (or) tholeiitic basalt dike-sill complexes-A preliminary deposit model

    Science.gov (United States)

    Schulz, Klaus J.; Chandler, Val W.; Nicholson, Suzanne W.; Piatak, Nadine M.; Seal, Robert R., II; Woodruff, Laurel G.; Zientek, Michael L.

    2010-01-01

    Magmatic sulfide deposits containing nickel (Ni) and copper (Cu), with or without (?) platinum-group elements (PGEs), account for approximately 60 percent of the world's Ni production and are active exploration targets in the United States and elsewhere. On the basis of their principal metal production, magmatic sulfide deposits in mafic rocks can be divided into two major types: those that are sulfide-rich, typically with 10 to 90 percent sulfide minerals, and have economic value primarily because of their Ni and Cu contents; and those that are sulfide-poor, typically with 0.5 to 5 percent sulfide minerals, and are exploited principally for PGE. Because the purpose of this deposit model is to facilitate the assessment for undiscovered, potentially economic magmatic Ni-Cu?PGE sulfide deposits in the United States, it addresses only those deposits of economic significance that are likely to occur in the United States on the basis of known geology. Thus, this model focuses on deposits hosted by small- to medium-sized mafic and (or) ultramafic dikes and sills that are related to picrite and tholeiitic basalt magmatic systems generally emplaced in continental settings as a component of large igneous provinces (LIPs). World-class examples (those containing greater than 1 million tons Ni) of this deposit type include deposits at Noril'sk-Talnakh (Russia), Jinchuan (China), Pechenga (Russia), Voisey's Bay (Canada), and Kabanga (Tanzania). In the United States, this deposit type is represented by the Eagle deposit in northern Michigan, currently under development by Kennecott Minerals.

  18. Nanostructured Multilayer Composite Films of Manganese Dioxide/Nickel/Copper Sulfide Deposited on Polyethylene Terephthalate Supporting Substrate

    Directory of Open Access Journals (Sweden)

    Awangku Nabil Syafiq Bin Awangku Metosen

    2015-01-01

    Full Text Available Nanostructured multilayer manganese dioxide/nickel/copper sulfide (MnO2/Ni/CuS composite films were successfully deposited onto supporting polyethylene terephthalate (PET substrate through the sequential deposition of CuS, Ni, and MnO2 thin films by chemical bath deposition, electrodeposition, and horizontal submersion deposition techniques, respectively. Deposition of each thin-film layer was optimized by varying deposition parameters and conditions associated with specific deposition technique. Both CuS and Ni thin films were optimized for their electrical conductivity whereas MnO2 thin film was optimized for its microstructure and charge capacity. The electrochemical properties of nanostructured multilayer MnO2/Ni/CuS composite films were evaluated by cyclic voltammetry as electrode materials of an electrochemical capacitor prototype in a dual-planar device configuration. Cyclic voltammogram in mild Na2SO4 aqueous electrolyte exhibited a featureless and almost rectangular shape which was indicative of the ideal capacitive behavior and high cycling reversibility of the electrochemical capacitor prototype. Nanostructured multilayer MnO2/Ni/CuS composite films on supporting polyethylene terephthalate (PET substrate could potentially be utilized as electrode materials for the fabrication of high performance electrochemical capacitors.

  19. Size-tunable copper nanocluster aggregates and their application in hydrogen sulfide sensing on paper-based devices

    Science.gov (United States)

    Chen, Po-Cheng; Li, Yu-Chi; Ma, Jia-Yin; Huang, Jia-Yu; Chen, Chien-Fu; Chang, Huan-Tsung

    2016-01-01

    Polystyrene sulfonate (PSS), a strong polyelectrolyte, was used to prepare red photoluminescent PSS-penicillamine (PA) copper (Cu) nanoclusters (NC) aggregates, which displayed high selectivity and sensitivity to the detection of hydrogen sulfide (H2S). The size of the PSS-PA-Cu NC aggregates could be readily controlled from 5.5 μm to 173 nm using different concentrations of PSS, which enabled better dispersity and higher sensitivity towards H2S. PSS-PA-Cu NC aggregates provided rapid H2S detection by using the strong Cu-S interaction to quench NC photoluminescence as a sensing mechanism. As a result, a detection limit of 650 nM, which is lower than the maximum level permitted in drinking water by the World Health Organization, was achieved for the analysis of H2S in spring-water samples. Moreover, highly dispersed PSS-PA-Cu NC aggregates could be incorporated into a plate-format paper-based analytical device which enables ultra-low sample volumes (5 μL) and feature shorter analysis times (30 min) compared to conventional solution-based methods. The advantages of low reagent consumption, rapid result readout, limited equipment, and long-term storage make this platform sensitive and simple enough to use without specialized training in resource constrained settings. PMID:27113330

  20. Sonochemical synthesis of copper II sulfide nanoparticles and their use as radiolytic stabilizer in poly(methyl methacrylate) matrix

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Marilia Cordeiro C. de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S., E-mail: aquino@ufpe.b [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-07-01

    Copper (II) sulfide (CuS) was synthesized by sonochemical method. Cu S crystals with hexagonal structure exhibit irregular particles with an average size in the range of 250-900 nm. Commercial Poly(methyl methacrylate) (PMMA) containing CuS nanoparticles (PMMA/Cu) at concentrations of 0.15; 0.30; 0.45 and 0.60 wt% were investigated. The samples were irradiated with gamma radiation ({sup 60}Co) at room temperature and air atmosphere. The viscosity-average molar mass (Mv) was measured for PMMA systems without nanoparticles and with nanoparticles. Decrease in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of CuS nanoparticles at 0.3 wt% into PMMA matrix decreased the number of main chain scissions at dose of 25 kGy and was calculated a protection of 50% in PMMA matrix. CuS nanoparticles act as free radical scavenger into gamma-irradiated PMMA systems. Changes in the infrared spectra of PMMA systems indicate that polymer molecules interact with CuS nanoparticles. Improvement of mechanical properties was found for PMMA/Cu films. An increase of 38% of Young's modulus value and a decrease of 22% on the elongation at break value were recorded for PMMA/Cu films exposed to gamma irradiation. (author)

  1. Activatable Multifunctional Persistent Luminescence Nanoparticle/Copper Sulfide Nanoprobe for in Vivo Luminescence Imaging-Guided Photothermal Therapy.

    Science.gov (United States)

    Chen, Li-Jian; Sun, Shao-Kai; Wang, Yong; Yang, Cheng-Xiong; Wu, Shu-Qi; Yan, Xiu-Ping

    2016-12-07

    Multifunctional nanoprobes that provide diagnosis and treatment features have attracted great interest in precision medicine. Near-infrared (NIR) persistent luminescence nanoparticles (PLNPs) are optimal materials due to no in situ excitation needed, deep tissue penetration, and high signal-to-noise ratio, while activatable optical probes can further enhance signal-to-noise ratio for the signal turn-on nature. Here, we show the design of an activatable multifunctional PLNP/copper sulfide (CuS)-based nanoprobe for luminescence imaging-guided photothermal therapy in vivo. Matrix metalloproteinases (MMPs)-specific peptide substrate (H2N-GPLGVRGC-SH) was used to connect PLNP and CuS to build a MMP activatable system. The nanoprobe not only possesses ultralow-background for in vivo luminescence imaging due to the absence of autofluorescence and optical activatable nature but also offers effective photothermal therapy from CuS nanoparticles. Further bioconjugation of c(RGDyK) enables the nanoprobe for cancer-targeted luminescence imaging-guided photothermal therapy. The good biocompatibility and the multiple functions of highly sensitive tumor-targeting luminescence imaging and effective photothermal therapy make the nanoprobe promising for theranostic application.

  2. Effect of Copper Sulfide Nanoparticles on the Optical and Electrical Behavior of Poly(vinyl alcohol) Films

    Science.gov (United States)

    Abdullah, Omed Gh.; Saleem, Salwan A.

    2016-11-01

    Polymer nanocomposite films based on poly(vinyl alcohol) (PVA) containing copper sulfide nanoparticles (CuS) were prepared using in situ chemical reduction and casting techniques. The synthesized nanocomposites were analyzed using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope, and ultraviolet-visible spectroscopy. The XRD pattern reveals that the CuS nanoparticles incorporated in the PVA showed a crystalline nature. The observed FTIR band shifts indicate the intermolecular interaction between the CuS nanoparticles and the PVA matrix. The absorbance of nanocomposite samples increased with increasing CuS concentration. The optical band gap energy was estimated using Tauc's formula and it decreased with increasing dopant concentration. The conductivity and dielectric behavior of the samples were studied over the frequency range of 300 Hz to 1 MHz in the temperature range of 30-110°C. The ac conductivity was found to increase with the increase of dopant concentration as well as frequency. Moreover, the variation of frequency exponent ( s) indicated that the conduction mechanism was the correlated barrier hopping model. The experimental results reveal that the optical and electrical performance of PVA can be enhanced dramatically by the addition of a small amount of CuS nanoparticles. This improved properties of the PVA/CuS nanocomposite suggest uses in optoelectronic devices.

  3. Application of ultrasonic radiation for simultaneous removal of auramine O and safranine O by copper sulfide nanoparticles: Experimental design

    Science.gov (United States)

    Ghaedi, Mehrorang; Khodadoust, Saeid; Sadeghi, Hossein; Khodadoust, Mohammad Ali; Armand, Raham; Fatehi, Allahdad

    2015-02-01

    In this study, copper sulfide nanoparticles loaded on activated carbon (CuS-NP-AC) were synthesized by novel, low cost and green approach and characterized using SEM and XRD. The application of this material for the simulations removal of auramine O (AO) and safranine O (SO) from aqueous solutions was investigated. The dependency of removal percentages to variables such as pH, initial dyes concentration, adsorbent dosage, sonication time and sonication temperature were studied with response surface methodology (RSM) by considering the desirability function (DF). The quadratic model between the dependent and the independent variables was built. The proposed method showed good agreement between the experimental data and predictive value, and it has been successfully employed to removal of AO and SO in aqueous media. The studied adsorbent (0.06 g of CuS-NP-AC) was capable of high percentage removal (99.8% and 99.5%) of 18 mg mL-1 AO and SO in short time (7.0 min).

  4. Application of ultrasonic radiation for simultaneous removal of auramine O and safranine O by copper sulfide nanoparticles: experimental design.

    Science.gov (United States)

    Ghaedi, Mehrorang; Khodadoust, Saeid; Sadeghi, Hossein; Khodadoust, Mohammad Ali; Armand, Raham; Fatehi, Allahdad

    2015-02-05

    In this study, copper sulfide nanoparticles loaded on activated carbon (CuS-NP-AC) were synthesized by novel, low cost and green approach and characterized using SEM and XRD. The application of this material for the simulations removal of auramine O (AO) and safranine O (SO) from aqueous solutions was investigated. The dependency of removal percentages to variables such as pH, initial dyes concentration, adsorbent dosage, sonication time and sonication temperature were studied with response surface methodology (RSM) by considering the desirability function (DF). The quadratic model between the dependent and the independent variables was built. The proposed method showed good agreement between the experimental data and predictive value, and it has been successfully employed to removal of AO and SO in aqueous media. The studied adsorbent (0.06 g of CuS-NP-AC) was capable of high percentage removal (99.8% and 99.5%) of 18 mg mL(-1) AO and SO in short time (7.0 min). Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Facile fabrication of novel porous graphitic carbon nitride/copper sulfide nanocomposites with enhanced visible light driven photocatalytic performance.

    Science.gov (United States)

    Chen, Xi; Li, Huankun; Wu, Yuxin; Wu, Hanshuo; Wu, Laidi; Tan, Pengfei; Pan, Jun; Xiong, Xiang

    2016-08-15

    In this work, a novel organic-inorganic heterostructured photocatalyst: porous graphitic carbon nitride (g-C3N4) hybrid with copper sulfide (CuS) had been synthesized via a precipitation-deposition method at low temperature for the first time. UV-vis spectroscopy revealed the porous g-C3N4/CuS nanocomposites showed a strong and broad visible light absorption. Furthermore, the g-C3N4/CuS nanocomposites showed higher photocatalytic activity in the photodegradation of various organic dyes than that of pure g-C3N4 and CuS, and the selected sample of g-C3N4/CuS-2 exhibited the best photocatalytic activity under visible light. The good photocatalytic activity could be ascribed to the matching of the g-C3N4 and CuS band gap energies. Besides, photoluminescent spectra and photoelectrochemical measurements also proved that the CuS/g-C3N4 could greatly enhance the charge generation and suppress the charge recombination of photogenerated carriers. According to the experimental result, a possible photocatalytic mechanism has been proposed. Due to the high stability, the porous g-C3N4/CuS could be applied in the field of environmental remediation. Our work highlights that coupling semiconductors with well-matched band energies provides a facile way to improve the photocatalytic activity.

  6. Photocatalytic, optical and electrical properties of copper-doped zinc sulfide thin films

    Science.gov (United States)

    Mohamed, S. H.

    2010-01-01

    Thin films of ZnS : Cu nanoparticles were prepared by electron beam evaporation on glass substrates. The Cu content was varied from 0 to 9 at%. XRD examination of the as-prepared films revealed the presence of polycrystalline hexagonal ZnS with preferred orientation depending on the Cu content. As annealing was carried out, grain growth was observed and a new orthorhombic copper sulfate phase emerged. The photocatalytic behaviour of ZnS : Cu was mainly evaluated by measuring the decomposition of methylene blue. The photocatalytic activities were found to decrease with increasing Cu content as well as with increasing annealing temperature. The optical transmittance and reflectance measurements were performed using a spectrophotometer. The spectral transmittance was decreased and the band gap energy was shifted from 3.45 to 3.20 eV with increasing Cu content. The refractive index was determined from transmittance using the Swanepoel method. The refractive index was found to depend on Cu content as well as annealing temperature. A strong decrease in room temperature resistivity was obtained with increasing Cu content. The obtained results are interesting and may find applications in photodegradation of pollutants and future display devices.

  7. Corrosion of copper and authigenic sulfide mineral growth in hydrothermal bentonite experiments

    Science.gov (United States)

    Caporuscio, F. A.; Palaich, S. E. M.; Cheshire, M. C.; Jové Colón, C. F.

    2017-03-01

    The focus of this experimental work is to characterize interaction of bentonite with possible used-fuel waste container materials. Experiments were performed up to 300 °C at 150-160 bars for five to six weeks. Bentonite was saturated with a 1900 ppm K-Ca-Na-Cl-bearing water with Cu-foils. Copper rapidly degrades into chalcocite (CuS2) and minor covellite (CuS) in the presence of H2S. Chalcocite growth and corrosion pit depths were measured for four different experimental runs yielding corrosion rates between 8.8 and 116 μm/yr depending on duration of experiment, brine composition, and clay type (bentonite vs. Opalinus Clay). Results of this research show that although pit-corrosion is demonstrated on Cu substrates, experiments show that the reactions that ensue, and the formation of minerals that develop, are extraordinarily slow. This supports the use of Cu in nuclide-containment systems as a possible engineered barrier system material.

  8. Copper isotope fractionation during sulfide-magma differentiation in the Tulaergen magmatic Ni-Cu deposit, NW China

    Science.gov (United States)

    Zhao, Yun; Xue, Chunji; Liu, Sheng-Ao; Symons, David T. A.; Zhao, Xiaobo; Yang, Yongqiang; Ke, Junjun

    2017-08-01

    Although it has been recently demonstrated that Cu isotope fractionation during mantle melting and basaltic magma differentiation is limited, the behavior of Cu isotopes during magmatic differentiation involving significant sulfide segregation remains unclear. Magmatic Ni-Cu deposits, which formed via sulfide segregation from basaltic or picritic magmas, are appropriate targets to address this issue. Here we report Cu isotope data for sulfides (chalcopyrite) from the Tulaergen Ni-Cu sulfide deposit in Xinjiang, NW China. Sulfides, including sparsely disseminated (hosted by hornblende gabbro), moderately disseminated (hosted by hornblende olivine websterite), densely disseminated (hosted by hornblende lherzolite) and massive sulfides (sandwiched between country rocks and mafic-ultramafic rocks), were collected from adits at 1050 m, 1100 m and 1150 m levels. The sparsely and moderately disseminated sulfides on 1150 m and 1050 m levels have a restricted range of δ65Cu values from - 0.38‰ to 0.15‰, whereas disseminated and massive sulfides on 1100 m level have δ65Cu values ranging widely from - 1.98‰ to - 0.04‰ and from - 1.08‰ to - 0.52‰, respectively. The δ65Cu values of disseminated sulfides are negatively correlated with whole-rock S and Cu concentrations, and sulfides formed at later stages have heavier δ65Cu values. These observations suggest significant Cu isotope fractionation during sulfide-magma differentiation above 600 °C. During the formation of the Tulaergen magmatic Ni-Cu deposit, sulfide segregation and crystallization of olivine and pyroxene caused the increase of Fe3 + contents in the residual magmas, which would move the redox reaction Cu+ + Fe3 + = Fe2 + + Cu2 + toward larger amounts of Cu2 + in the melt. The presence of Cu2 + in melt allowed redox transformation to happen during sulfide segregation. The residual magmas are enriched in heavy Cu isotopes due to the removal of 65Cu-depleted sulfides, and sulfides formed at later

  9. Reaction Mechanisms of Metals with Hydrogen Sulfide and Thiols in Model Wine. Part 2: Iron- and Copper-Catalyzed Oxidation.

    Science.gov (United States)

    Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

    2016-05-25

    Sulfidic off-odors arising during wine production are frequently removed by Cu(II) fining. In part 1 of this study ( 10.1021/acs.jafc.6b00641 ), the reaction of H2S and thiols with Cu(II) was examined; however, the interaction of iron and copper is also known to play an important synergistic role in mediating non-enzymatic wine oxidation. The interaction of these two metals in the oxidation of H2S and thiols (cysteine, 3-sulfanylhexan-1-ol, and 6-sulfanylhexan-1-ol) was therefore examined under wine-like conditions. H2S and thiols (300 μM) were reacted with Fe(III) (100 or 200 μM) alone and in combination with Cu(II) (25 or 50 μM), and concentrations of H2S and thiols, oxygen, and acetaldehyde were monitored over time. H2S and thiols were shown to be slowly oxidized in the presence of Fe(III) alone and were not bound to Fe(III) under model wine conditions. However, Cu(II) added to model wine containing Fe(III) was quickly reduced by H2S and thiols to form Cu(I) complexes, which then rapidly reduced Fe(III) to Fe(II). Oxidation of Fe(II) in the presence of oxygen regenerated Fe(III) and completed the iron redox cycle. In addition, sulfur-derived oxidation products were observed, and the formation of organic polysulfanes was demonstrated.

  10. A Comparative Study of Hollow Copper Sulfide Nanoparticles and Hollow Gold Nanospheres on Degradability and Toxicity

    Science.gov (United States)

    Guo, Liangran; Panderi, Irene; Yan, Daisy D.; Szulak, Kevin; Li, Yajuan; Chen, Yi-Tzai; Ma, Hang; Niesen, Daniel B.; Seeram, Navindra; Ahmed, Aftab; Yan, Bingfang; Pantazatos, Dionysios; Lu, Wei

    2013-01-01

    Gold and copper nanoparticles have been widely investigated for photothermal therapy of cancer. However, degradability and toxicity of these nanoparticles remain concerns. Here, we compare hollow CuS nanoparticles (HCuSNPs) with hollow gold nanospheres (HAuNS) in similar particle sizes and morphology following intravenous administration to mice. The injected pegylated HCuSNPs (PEG-HCuSNPs) are eliminated through both hepatobiliary (67 percentage of injected dose, %ID) and renal (23 %ID) excretion within one month post injection. By contrast, 3.98 %ID of Au is excreted from liver and kidney within one month after i.v. injection of pegylated HAuNS (PEG-HAuNS). Comparatively, PEG-HAuNS are almost non-metabolizable, while PEG-HCuSNPs are considered biodegradable nanoparticles. PEG-HCuSNPs do not show significant toxicity by histological or blood chemistry analysis. Principal component analysis and 2-D peak distribution plots of data from matrix-assisted laser desorption ionization-time of flight imaging mass spectrometry (MALDI-TOF IMS) of liver tissues demonstrated a reversible change in the proteomic profile in mice receiving PEG-HCuSNPs. This is attributed to slow dissociation of Cu ion from CuS nanoparticles along with effective Cu elimination for maintaining homeostasis. Nonetheless, an irreversible change in the proteomic profile is observed in the liver from mice receiving PEG-HAuNS by analysis of MALDI-TOF IMS data, probably due to the non-metabolizability of Au. This finding correlates with the elevated serum lactate dehydrogenase at 3 months after PEG-HAuNS injection, indicating potential long-term toxicity. The comparative results between the two types of nanoparticles will advance the development of HCuSNPs as a new class of biodegradable inorganic nanomaterials for photothermal therapy. PMID:24053214

  11. Synthesis of ultrastable copper sulfide nanoclusters via trapping the reaction intermediate: potential anticancer and antibacterial applications.

    Science.gov (United States)

    Wang, Hong-Yin; Hua, Xian-Wu; Wu, Fu-Gen; Li, Bolin; Liu, Peidang; Gu, Ning; Wang, Zhifei; Chen, Zhan

    2015-04-01

    Copper-based nanomaterials have broad applications in electronics, catalysts, solar energy conversion, antibiotics, tissue imaging, and photothermal cancer therapy. However, it is challenging to prepare ultrasmall and ultrastable CuS nanoclusters (NCs) at room temperature. In this article, a simple method to synthesize water-soluble, monodispersed CuS NCs is reported based on the strategy of trapping the reaction intermediate using thiol-terminated, alkyl-containing short-chain poly(ethylene glycol)s (HS-(CH2)11-(OCH2CH2)6-OH, abbreviated as MUH). The MUH-coated CuS NCs have superior stability in solutions with varied pH values and are stable in pure water for at least 10 months. The as-prepared CuS NCs were highly toxic to A549 cancer cells at a concentration of higher than 100 μM (9.6 μg/mL), making them be potentially applicable as anticancer drugs via intravenous administration by liposomal encapsulation or by direct intratumoral injection. Besides, for the first time, CuS NCs were used for antibacterial application, and 800 μM (76.8 μg/mL) CuS NCs could completely kill the E. coli cells through damaging the cell walls. Moreover, the NCs synthesized here have strong near-infrared (NIR) absorption and can be used as a candidate reagent for photothermal therapy and photoacoustic imaging. The method of trapping the reaction intermediate for simple and controlled synthesis of nanoclusters is generally applicable and can be widely used to synthesize many metal-based (such as Pt, Pd, Au, and Ag) nanoclusters and nanocrystals.

  12. Metallurgical behavior of fine fractions of copper sulfide minerals in a combined process of modified flotation and agitated bio leaching; Respuesta metalurgica de fracciones finas de minerales sulfurados de cobre en un proceso combinado de flotacion modificada y biolixiviacion agitada

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, J. P.; Ipinza, J.; Collao, N.; Ahlborn, G.

    2007-07-01

    The metallurgical behaviour of fine fraction of copper sulfide minerals of Compania Minera Quebrada Blanca S. A. was studied by concentration through flotation in aqueous media modified by alcohol followed by bio leaching of the concentrates. By using a 1% v/v of methanol, the metallurgical recovery of copper reaches 88%, while the iron recovery was 43%, the weight recovery was 18%, which indicates a high selectivity. these concentrates were then bio leached with and without nutrient medium, reaching 80% of copper recovery after 10 and 17 days, respectively. then, it is possible to conclude that this concentration-bio leaching metallurgical process is a promising route for copper recovery from the fine fraction of sulfide minerals. (Author) 24 refs.

  13. Petrography, sulfide mineral chemistry, and sulfur isotope evidence for a hydrothermal imprint on Musina copper deposits, Limpopo Province, South Africa: Evidence for a breccia pipe origin?

    Science.gov (United States)

    Chaumba, Jeff B.; Mundalamo, Humbulani R.; Ogola, Jason S.; Cox, J. A.; Fleisher, C. J.

    2016-08-01

    The Musina copper deposits are located in the Central Zone of the Limpopo orogenic belt in Limpopo Province, South Africa. We carried out a petrographic, sulfide composition, and δ34S study on samples from Artonvilla and Campbell copper deposits and a country rock granitic gneiss to Artonvilla Mine to place some constrains on the origin of these deposits. The assemblages at both Artonvilla and Campbell Mines of brecciated quartz, potassium feldspar, muscovite, chlorite, calcite, and amphibole are consistent with sericitic alteration. Quartz, amphibole, feldspars, and micas often display angular textures which are consistent with breccias. Sulfur concentrations in pyrite from Artonvilla Mine plot in a narrow range, from 50.2 wt. % to 55.7 wt. %. With the exception of a positive correlation between Fe and Cu, no well defined correlations are shown by data from the Musina copper deposits. The occurrence of sulfides both as inclusions in, or as interstitial phases in silicates, suggests that hydrothermal alteration that affected these deposits most likely helped concentrate the mineralization at the Musina copper deposits. Sulfur concentrations in chalcopyrite samples investigated vary widely whereas the copper concentrations in chalcopyrite are not unusually higher compared to those from chalcopyrite from other tectonic settings, probably indicating that either the Cu in the Musina copper deposits occurs in native form, and/or that it is hosted by other phases. This observation lends support to the Cu having been concentrated during a later hydrothermal event. One sample from Artonvilla Mine (AtCal01) yielded pyrite δ34S values of 3.1and 3.6‰ and chalcopyrite from the same sample yielded a value of 3.9‰. A country rock granitic gneiss to Artonvilla Mine yielded a δ34Spyrite value of 8.2‰. For Campbell Mine samples, one quartz vein sample has a δ34Spyrite value of 0.5‰ whereas chalcopyrite samples drilled from different areas within the same sample yielded

  14. Changes in the composition of an acid mine drainage microbial community upon successive transfers in medium containing low-grade copper sulfide.

    Science.gov (United States)

    Liu, Yi; Yin, Huaqun; Liang, Yili; Shen, Li; Liu, Yao; Fu, Xian; Baba, Ngom; Zeng, Weimin; Qiu, Guanzhou; Liu, Xueduan

    2011-10-01

    A consortium of microorganisms from acid mine drainage samples was cultured in modified 9 K medium containing low-grade copper sulfide. The culture was maintained for sixty days and then transferred to fresh medium. This process was repeated three more times and a final consortium exhibiting a copper extraction rate of 89.3% was obtained. RFLP and microarrays analysis of 16S rRNA sequences retrieved from the consortia showed that Acidithiobacilluscaldus, Leptospirillumferriphilum, Sulfobacillus sp., Acidiphilium sp., and Sulfolobus spp. were represented in higher numbers in the consortia obtained in the copper-containing medium than in the original consortium. In contrast, a decrease in Acidithiobacillus ferrooxidans, Alicyclobacillus sp., Pseudomonas sp., and Sulfobacillus thermosulfidooxidans was observed. The abundance of genes related to sulfur metabolism from At. caldus and Sulfolobus spp., iron oxidation from Leptospirillum sp. and metal resistance from most of the detected microorganisms increased as the consortium was successively transferred into fresh medium. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. 赞比亚某铜钴硫化矿浮选工艺研究%A Flotation Process for a Copper-Cobalt Sulfide Ore from Zambia

    Institute of Scientific and Technical Information of China (English)

    朱景和; 陈新林; 马忠臣

    2014-01-01

    赞比亚某铜钴硫化矿含铜1.25%、钴0.088%。针对该矿石的工艺矿物学特征,进行了不同药剂种类及用量的条件试验,确定了铜钴混合浮选-铜钴分离的工艺流程。闭路试验获得了含铜31.52%、铜回收率为92.32%、含钴0.232%的铜精矿和含钴2.12%、钴回收率67.56%、含铜1.48%的钴精矿的较好指标。%A Copper-Cobalt sulfide ore in Zambia containing 1 .25% Cu , 0 .088% Co , based on the charac-teristic of process mineralogy of the ore , the reagent sieving and dosage tests were carried out , and finally the process combination flowsheet of Cu -Co bulk flotation , followed by Cu -Co separation flotation was determined . Good indexes were achieved by the closed -circuit test , and the concentrates of copper and co-balt was obtained , while copper concentrate containing 31 .52% Cu and 0 .232% Co with copper recovery of 92 .32% and cobalt concentrate containing 2 .12% Co and 1 .48% Cu with cobalt recovery of 67 .56% .

  16. Electrical and thermal transports of binary copper sulfides CuxS with x from 1.8 to 1.96

    Science.gov (United States)

    Qiu, Pengfei; Zhu, Yaqin; Qin, Yuting; Shi, Xun; Chen, Lidong

    2016-10-01

    In this study, a series of copper sulfides CuxS with x spanning from 1.8 to 1.96 was prepared and their crystal structures, elemental valence states, and thermoelectric properties were systematically studied. The valence state of Cu in CuxS is unchanged as the ratio of Cu/S varies, while the thermoelectric properties are very sensitive to the deficiency of Cu. In addition, the type of sulfur arrangement in the crystal structure also plays an important role on the electrical transports. Finally, the optimum Cu/S atomic ratios in the binary CuxS system were identified for high power factor and thermoelectric figure of merit.

  17. Removal of copper from ferrous scrap

    Science.gov (United States)

    Blander, Milton; Sinha, Shome N.

    1990-01-01

    A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

  18. The Effect of Ferrous Sulfate on Sulfide-Induced Corrosion of Copper-Base Condenser Alloys in Aerated Seawater.

    Science.gov (United States)

    1982-01-01

    of sulfide into an otherwise aerated seawater environment. Previous research by Effertz and Fichte 26 has identified many of the fundamentals involved...Sato, S., Reviews on Coatings and Corrosion, p. 139 (1973). 26. Effertz, P. H., and W. Fichte , VCB Kraftwenkstechnik, Vol. 57, No. 2 (Feb 1977). 27

  19. Copper(II)-Mediated Hydrogen Sulfide and Thiol Oxidation to Disulfides and Organic Polysulfanes and Their Reductive Cleavage in Wine: Mechanistic Elucidation and Potential Applications.

    Science.gov (United States)

    Kreitman, Gal Y; Danilewicz, John C; Jeffery, David W; Elias, Ryan J

    2017-03-29

    Fermentation-derived volatile sulfur compounds (VSCs) are undesirable in wine and are often remediated in a process known as copper fining. In the present study, the addition of Cu(II) to model and real wine systems containing hydrogen sulfide (H2S) and thiols provided evidence for the generation of disulfides (disulfanes) and organic polysulfanes. Cu(II) fining of a white wine spiked with glutathione, H2S, and methanethiol (MeSH) resulted in the generation of MeSH-glutathione disulfide and trisulfane. In the present study, the mechanisms underlying the interaction of H2S and thiols with Cu(II) is discussed, and a prospective diagnostic test for releasing volatile sulfur compounds from their nonvolatile forms in wine is investigated. This test utilized a combination of reducing agents, metal chelators, and low-oxygen conditions to promote the release of H2S and MeSH, at levels above their reported sensory thresholds, from red and white wines that were otherwise free of sulfidic off-odors at the time of addition.

  20. Sorption mechanisms of iodide ions on oxides and divided copper sulfides; environmental outlook; Mecanismes de sorption des ions iodure sur les oxydes et les sulfures de cuivre divises; perspectives environnementales

    Energy Technology Data Exchange (ETDEWEB)

    Lefevre, G

    1999-10-15

    The radioactive iodine released in environment is a great risk for health. Copper compounds have a sufficient affinity for tracking this element inside a solid phase. These researches are useful in 1)the obtention of a hatch material hindering the iodine 129, released by nuclear wastes, to reach the biosphere, 2)the development of decontamination processes, 3)the forecast of the becoming of iodine in the environment, and 4)the design of analyses methods based on a iodine preconcentration on a solid. Three copper systems have been used: Cu{sub 2}O, copper sulfides (Cu{sub 2}S, CuFeS{sub 2} and CuS) and the mixture metallic copper/copper(II)carbonate. CuI is formed on Cu{sub 2}O in acid solutions. The adsorption of iodines occur in basic solutions, by exchange with Cu{sub 2}O surface hydroxyls, which losses its fixation properties if a reduction potential transforms it into metallic copper. An electrochemical analysis method of the iodine by preconcentration on Cu{sub 2}O in acid solution has been developed; its detection limit is of 5.10{sup -7} M. The three sulfide used (Cu{sub 2}S, CuFeS{sub 2} and CuS) adsorb the iodides. The similarity of their reactivity is due to the presence of copper(I). The stability of Cu{sub 2}S and CuFeS{sub 2} could allow to these compounds to keep their efficiency to the reducing potentials of the underground medium. At last, when they are into contact with a metallic copper/azurite mixture, the iodides precipitate to the copper surface. This study is then a synthesis of the properties of the copper(I) systems towards iodides in high concentration ({>=}10{sup -4} M). (O.M.)

  1. Avaliação da influência de sulfetos solúveis na complexação do cobre em águas superficiais empregando métodos voltamétricos Influence of dissolved sulfides on copper complexation in surface waters using voltammetric methods

    Directory of Open Access Journals (Sweden)

    Elizabeth W. O. Scheffer

    2010-01-01

    Full Text Available In this work a sulfide quantification protocol using voltammetric methods was developed to evaluate the effect of dissolved sulfides on copper complexation. On the basis of pH, sulfide release from the dissociation of specific metal sulfide complexes can be electrochemically measured and then removed (as H2S by a N2 purge. Cathodic stripping square wave voltammetry (CSSWV was conducted to quantify Cu sulfides complexes which dissociate at pH < 5.0 during the process of acid titration.

  2. Facile room-temperature synthesis of carboxylated graphene oxide-copper sulfide nanocomposite with high photodegradation and disinfection activities under solar light irradiation

    Science.gov (United States)

    Yu, Shuyan; Liu, Jincheng; Zhu, Wenyu; Hu, Zhong-Ting; Lim, Teik-Thye; Yan, Xiaoli

    2015-11-01

    Carboxylic acid functionalized graphene oxide-copper (II) sulfide nanoparticle composite (GO-COOH-CuS) was prepared from carboxylated graphene oxide and copper precursor in dimethyl sulfoxide (DMSO) by a facile synthesis process at room temperature. The high-effective combination, the interaction between GO-COOH sheets and CuS nanoparticles, and the enhanced visible light absorption were confirmed by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra. The as-synthesized GO-COOH-CuS nanocomposite exhibited excellent photocatalytic degradation performance of phenol and rhodamine B, high antibacterial activity toward E. coli and B. subtilis, and good recovery and reusability. The influence of CuS content, the synergistic reaction between CuS and GO-COOH, and the charge-transfer mechanism were systematically investigated. The facile and low-energy synthesis process combined with the excellent degradation and antibacterial performance signify that the GO-COOH-CuS has a great potential for water treatment application.

  3. Sulfide oxidation and distribution of metals near abandoned copper mines in coastal environments, Prince William Sound, Alaska, USA

    Science.gov (United States)

    Koski, R.A.; Munk, L.; Foster, A.L.; Shanks, Wayne C.; Stillings, L.L.

    2008-01-01

    The oxidation of sulfide-rich rocks, mostly leftover debris from Cu mining in the early 20th century, is contributing to metal contamination of local coastal environments in Prince William Sound, Alaska. Analyses of sulfide, water, sediment, precipitate and biological samples from the Beatson, Ellamar, and Threeman mine sites show that acidic surface waters generated from sulfide weathering are pathways for redistribution of environmentally important elements into and beyond the intertidal zone at each site. Volcanogenic massive sulfide deposits composed of pyrrhotite and (or) pyrite + chalcopyrite + sphalerite with subordinate galena, arsenopyrite, and cobaltite represent potent sources of Cu, Zn, Pb, As, Co, Cd, and Hg. The resistance to oxidation among the major sulfides increases in the order pyrrhotite ??? sphalerite Hg (to 4100 ng/L) in the pore waters probably result from oxidation of sphalerite-rich rocks. The low-pH and high concentrations of dissolved Fe, Al, and SO4 are conducive to precipitation of interstitial jarosite in the intertidal gravels. Although pore waters from the intertidal zone at the Threeman mine site have circumneutral pH values, small amounts of dissolved Fe2+ in the pore waters are oxidized during mixing with seawater, resulting in precipitation of Fe-oxyhydroxide flocs along the beach-seawater interface. At the Beatson site, surface waters funneled through the underground mine workings and discharged across the waste dumps have near-neutral pH (6.7-7.3) and a relatively small base-metal load; however, these streams probably play a role in the physical transport of metalliferous particulates into intertidal and offshore areas during storm events. Somewhat more acidic fluids, to pH 5.3, occur in stagnant seeps and small streams emerging from the Beatson waste dumps. Amorphous Fe precipitates in stagnant waters at Beatson have high Cu (5.2 wt%) and Zn (2.3 wt%) concentrations that probably reflect adsorption onto the extremely high

  4. Temperature-dependent formation of metallic copper and metal sulfide nanoparticles during flooding of a contaminated soil

    Science.gov (United States)

    Hofacker, Anke F.; Voegelin, Andreas; Kaegi, Ralf; Weber, Frank-Andreas; Kretzschmar, Ruben

    2013-02-01

    Riparian floodplains in temperate regions are affected by pronounced seasonal variations in soil and water temperature. This affects the rates and interplay of microbial and abiotic geochemical processes that control the fate of metals in contaminated floodplain soils, including potential release into surface and groundwater during periodic flooding. Here, we investigated how temperature affects chalcophile trace metal contaminants (Cu, Cd, Pb) upon flooding of a riparian soil contaminated by past mining activities. In soil microcosms incubated at 23, 14, and 5 °C, the reductive dissolution of Mn(III,IV) and Fe(III) (oxyhydr)oxides and the release of dissolved Mn2+ and Fe2+ were significantly slower and less intense at the lower temperatures, which was reflected in a decrease of trace metal mobilization via the dissolution of metal oxide sorbents and cation competition for sorption sites. The onset of sulfate reduction was significantly delayed at lower temperatures and the apparent rate of sulfate reduction was decreased, especially at 5 °C. This resulted in elevated high dissolved Cu, Cd, and Pb concentrations over weeks of flooding at 5 °C, whereas colloidal metal sulfide formation dominated Cu, Cd, and Pb pore water dynamics at higher temperatures of 14 and 23 °C due to fast sulfate reduction. Cu K-edge X-ray absorption fine structure spectroscopy revealed metallic Cu(0) as the main colloidal Cu species prior to sulfate reduction at all three temperatures. Analytical electron microscopy showed that Cu(0) particles were associated with suspended bacteria, suggesting biomineralization of Cu(0). Upon onset of sulfate reduction, metallic Cu particles were transformed into CuxS with incorporation of smaller amounts of Cd and Pb. Concomitantly, freely dispersed mixed Cu-Cd-Pb sulfide nanoparticles precipitated in the pore water. Other metals with higher metal sulfide solubility products did not react with the limited amounts of biogenic sulfide. The median size

  5. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method

    Directory of Open Access Journals (Sweden)

    Jinzhan Su

    2016-06-01

    Full Text Available Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM, X-ray fluorescence-spectrometry (XRF, UV-Vis absorption spectra and X-ray diffraction (XRD to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na2S and Na2SO3 at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification.

  6. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method.

    Science.gov (United States)

    Su, Jinzhan; Zhang, Tao; Li, Yufeng; Chen, Yubin; Liu, Maochang

    2016-06-15

    Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS) photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM), X-ray fluorescence-spectrometry (XRF), UV-Vis absorption spectra and X-ray diffraction (XRD) to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na₂S and Na₂SO₃) at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification.

  7. 电沉积制备铜铟硫薄膜的研究%Preparation of Copper Indium Sulfide Film by Electro-Deposition Method

    Institute of Scientific and Technical Information of China (English)

    李丽波; 李琦; 王珩; 杨秀春; 田海燕; 谢菁琛; 王文涛

    2015-01-01

    Copper indium sulfide (CuinS2,CIS2) film was prepared by an electro-deposition method.Uv-vis spectrophotometer test result shows that the band gap of the electroplated CIS2 film is 1.5 eV.X-ray photoelectron spectroscopy (XPS) analysis reveals that the Cu,In and S signals corresponded to valence state (+1,+3 and-2) of three elements in CIS2 film,respectively.The photoelectrical properties of the CIS2 film were characterized by linear sweep voltammetry measurements under the dark and illumination.The I-V characteristic is linear under the dark and illumination,and the slope gap is 0.6× 10-3.We also simulated the band gap (1.5 eV) of the C[S2 film with chalcopyrite structure prepared by electroplating experiment using DMol3 and CASTEP modules,respectively.The molecular structure model of electroplated copper indium sulfide film has been established,and the X-ray diffraction simulative spectrum has been obtained by Materials Studio,which has good agreement with the experiment result.%采用电沉积的方法制备铜铟硫(CuInS2,CIS2)薄膜,紫外可见光谱仪测试结果表明电沉积制备的CIS2薄膜的禁带宽度为1.5 eV.X射线光电子能谱(XPS)分析表明,薄膜中的铜、铟、硫元素的价态分别为+1,+3和-2.采用线性伏安扫描测试了薄膜的光电性质,在黑暗和光照的条件下,I-V曲线斜率变化率为0.6×10-3.运用DMol3和CASTEP模块计算了电沉积制备的铜铟硫薄膜的禁带宽度,其数值为1.5 eV.通过Materials Studio建立了电沉积制备出的铜铟硫薄膜的结构和XRD模拟谱图,与实验结果一致.

  8. An efficient dual-loaded multifunctional nanocarrier for combined photothermal and photodynamic therapy based on copper sulfide and chlorin e6.

    Science.gov (United States)

    Tan, Xiaoxiao; Pang, Xiaojuan; Lei, Mingzhu; Ma, Man; Guo, Fang; Wang, Jinping; Yu, Meng; Tan, Fengping; Li, Nan

    2016-04-30

    The therapeutic effectiveness of photodynamic therapy (PDT) was hampered by the poor water solubility and instability in physiological conditions of the photosensitizers. Here, we designed folate conjugated thermosensitive liposomes (TSL) as the nanocarrier to improve the solubility, stability and biocompatibility of photosensitizer Chlorin e6 (Ce6). Based on the photothermal effect, we combined copper sulfide (CuS) as the photothermal agent to realize heat-triggered Ce6 release as well as synergistic effect of photothermal and photodynamic therapy. In vitro MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay showed that Ce6-CuS-TSL had low dark toxicity, while performed excellent phototoxicity under the combined 660 and 808 nm laser irradiation compared to any single laser irradiation alone. Moreover, in vivo combination therapy study revealed that Ce6-CuS-TSL inhibited tumor growth to a great extent without evident side effect under the laser irradiation. All detailed evidence demonstrated a considerable potential of Ce6-CuS-TSL for synergistic cancer treatment.

  9. An ultrasensitive electrochemiluminescence sensor based on reduced graphene oxide-copper sulfide composite coupled with capillary electrophoresis for determination of amlodipine besylate in mice plasma.

    Science.gov (United States)

    Wei, Yanfen; Wang, Hao; Sun, Shuangjiao; Tang, Lifu; Cao, Yupin; Deng, Biyang

    2016-12-15

    A new electrochemiluminescence (ECL) sensor based on reduced graphene oxide-copper sulfide (rGO-CuS) composite coupled with capillary electrophoresis (CE) was constructed for the ultrasensitive detection of amlodipine besylate (AML) for the first time. In this work, rGO-CuS composite was synthesized by one-pot hydrothermal method and used for electrode modification. The electrochemical and ECL behaviors of the sensor were investigated. More than 5-fold enhance in ECL intensity was observed after modified with rGO-CuS composite. The results can be ascribed to the presence of rGO-CuS composite on the electrode surface that facilitates the electron transfer rate between the electroactive center of Ru(bpy)3(2+) and the electrode. The ECL sensor was coupled with CE to improve the selectivity and the CE-ECL parameters that affect separation and detection were optimized. Under the optimum conditions, the linear ranges for AML was 0.008-5.0μg/mL with a detection limit of 2.8ng/mL (S/N=3). The method displayed the advantages of high sensitivity, good selectivity, wide linear range, low detection limit and fine reproducibility, and was used to analyze AML in mice plasma with a satisfactory result, which holds a great potential in the field of pharmaceutical analysis.

  10. One-step fabrication of copper sulfide nanoparticles decorated on graphene sheets as highly stable and efficient counter electrode for CdS-sensitized solar cells

    Science.gov (United States)

    Hessein, Amr; Wang, Feiju; Masai, Hirokazu; Matsuda, Kazunari; Abd El-Moneim, Ahmed

    2016-11-01

    Quantum-dot-sensitized solar cells (QDSSCs) are thin-film photovoltaics and highly promising as next-generation solar cells owing to their high theoretical efficiency, easy fabrication process, and low production cost. However, the practical photoconversion efficiencies (PCEs) of QDSSCs are still far below the theoretically estimated value owing to the lack of an applicable design of the materials and electrodes. In this work, we developed a highly stable and efficient counter electrode (CE) from copper sulfide nanocrystals and reduced graphene oxide (Cu x S@RGO) for QDSSC applications. The Cu x S@RGO electrocatalyst was successfully prepared by a facile one-pot hydrothermal method, then directly applied to a fluorine-doped tin oxide (FTO)-coated glass substrate by the simple drop-casting technique. Owing to the synergistic effect between Cu x S nanocrystals and conductive RGO sheets, the Cu x S@RGO CE showed high electrocatalytic activity for polysulfide electrolyte reduction. A CdS QDSSC based on the Cu x S@RGO CE yielded a high and reproducible PCE of 2.36%, exceeding those of 1.57 and 1.33% obtained with the commonly used Cu2S/brass and Pt CEs, respectively. Moreover, the QDSSC with the Cu x S@RGO CE showed excellent photostability in a light-soaking test without any obvious decay in the photocurrent, whereas the cell based on the Cu2S/brass CE was severely degraded.

  11. One-pot fabrication of FRET-based fluorescent probe for detecting copper ion and sulfide anion in 100% aqueous media

    Science.gov (United States)

    Lv, Kun; Chen, Jian; Wang, Hong; Zhang, Peisheng; Yu, Maolin; Long, Yunfei; Yi, Pinggui

    2017-04-01

    The design of effective tools for detecting copper ion (Cu2 +) and sulfide anion (S2 -) is of great importance due to the abnormal level of Cu2 + and S2 - has been associated with an increase in risk of many diseases. Herein, we report on the fabrication of fluorescence resonance energy transfer (FRET) based fluorescent probe PF (PEI-FITC) for detecting Cu2 + and S2 - in 100% aqueous media via a facile one-pot method by covalent linking fluorescein isothiocyanate (FITC) with branched-polyethylenimine (b-PEI). PF could selectively coordinate with Cu2 + among 10 metal ions to form PF-Cu2 + complex, resulting in fluorescence quenching through FRET mechanism. Furthermore, the in situ generated PF-Cu2 + complex can be used to selectively detect S2 - based on the displacement approach, resulting in an off-on type sensing. There is no obvious interference from other anions, such as Cl-, NO3-, ClO4-, SO42 -, HCO3-, CO32 -, Br-, HPO42 -, F- and S2O32 -. In addition, PF was successfully used to determine Cu2 + and S2 - in human serum and tap water samples. Therefore, the FRET-based probe PF may provide a new method for selective detection of multifarious analysts in biological and environmental applications, and even hold promise for application in more complicated systems.

  12. One-Pot Synthesis of Copper Sulfide Nanowires/Reduced Graphene Oxide Nanocomposites with Excellent Lithium-Storage Properties as Anode Materials for Lithium-Ion Batteries.

    Science.gov (United States)

    Feng, Caihong; Zhang, Le; Yang, Menghuan; Song, Xiangyun; Zhao, Hui; Jia, Zhe; Sun, Kening; Liu, Gao

    2015-07-29

    Copper sulfide nanowires/reduced graphene oxide (CuSNWs/rGO) nanocompsites are successfully synthesized via a facile one-pot and template-free solution method in a dimethyl sulfoxide (DMSO)-ethyl glycol (EG) mixed solvent. It is noteworthy that the precursor plays a crucial role in the formation of the nanocomposites structure. SEM, TEM, XRD, IR and Raman spectroscopy are used to investigate the morphological and structural evolution of CuSNWs/rGO nanocomposites. The as-fabricated CuSNWs/rGO nanocompsites show remarkably improved Li-storage performance, excellent cycling stability as well as high-rate capability compared with pristine CuS nanowires. It obtains a reversible capacity of 620 mAh g(-1) at 0.5C (1C = 560 mA g(-1)) after 100 cycles and 320 mAh g(-1) at a high current rate of 4C even after 430 cycles. The excellent lithium storage performance is ascribed to the synergistic effect between CuS nanowires and rGO nanosheets. The as-formed CuSNWs/rGO nanocomposites can effectively accommodate large volume changes, supply a 2D conducting network and trap the polysulfides generated during the conversion reaction of CuS.

  13. Development of high-efficiency solar cells on copper indium selenide single crystals (cadmium sulfide, zinc oxide)

    Energy Technology Data Exchange (ETDEWEB)

    Yip, Lap Sum

    1996-12-31

    Photovoltaic cells with a ZnO/CdS/CuInSe{sub 2} structure were fabricated on bulk CuInSe{sub 2} substrates. Conversion efficiencies of more than or near 10 per cent were obtained on cells with an active area and without the use of antireflection coating. Copper indium selenide single crystals can be used as absorbers in thin film solar cells. In this study, the single crystals were grown by a horizontal Bridgman method. An annealing of the CuInSe{sub 2} substrate before the CdS deposition was found to be essential in obtaining high photovoltaic performance.

  14. Fatores que governam a especiação do cobre em ambientes aquáticos urbanos: evidências da contribuição de sulfetos solúveis Factors governing copper speciation in urban freshwaters: evidences on the contribution of soluble sulfides

    Directory of Open Access Journals (Sweden)

    Elizabeth W. Scheffer

    2007-04-01

    Full Text Available Copper speciation and behavior in different rivers located in the city of Curitiba were evaluated in this work. Sampling locations were selected to cover different levels of urbanization regarding their anthropogenic occupation and land use. Results showed that in highly-developed areas, both organic matter and dissolved sulfides were able to control copper speciation. Dissolved sulfide species were the major complexing agent in areas where dissolved oxygen levels are low. Finally, it was demonstrated that in urban areas anthropogenic factors such as sewage inputs and occupation of the drainage basin are the key aspects controlling copper dynamics and speciation in river waters.

  15. Cherts from the Yangla copper deposit, western Yunnan Province: geochemical characteristics and relationship with massive sulfide mineralization

    Institute of Scientific and Technical Information of China (English)

    PAN; Jiayong; (

    2001-01-01

    [1]Wei Junqi, Zhan Mingguo, Lu Yuanfa et al., Geochemistry of granitoid from the Yangla ore district, Geology and Mineral Resources of South China (in Chinese), 1997 (4): 50.[2]He Longqing, Zhan Mingguo, Lu Yuanfa, Division of sequence stratigraphy and study on ore-bearing beds in the Yangla copper orefield, western Yunnan, Geology and Mineral Resources of South China (in Chinese), 1998 (3): 37.[3]Zhan Mingguo, Lu Yuanfa, Chen Shifang et al., Formation condition and type of the Yangla large scale copper deposit, Western Yunnan, Mineral Deposits (in Chinese), 1998, 17 (supplement): 183.[4]Lu Yuanfa, Chen Kaixu, Zhan Mingguo et al., Geochemical evidence of exhalative-sedimentary ore-bearing skarns in Yangla copper mineralization concentrated Area, Earth Science (in Chinese), 1999, 24(3): 298.[5]Yomamoto, K., Geochemical characteristics and depositional environments of cherts and associated rocks in the Franciscan and Shimanto terranes, Sedimentary Geology, 1987, 52: 65.[6]Zhou, Y. Z., Geochemical characteristics of siliceous rocks originated from a fossil hydrothermal system in the upper Devonian strata, Guangxi, southern China, Acta Sedimentologia, 1990, 8 (3): 75.[7]Zhou Yongzhang, Geology and Geochemistry of Hetai Gold Field, Southern China, Guangzhou: South China University of Technology Press, 1993, 53-107.[8]Bostroem, K., Harold, R., Oiva, J., Provenance and accumulation rates of opaline silica, Al, Fe, Tl, Mn, Cu, Ni and Co in Pacific pelagic sediment, Chem. Geol., 1973, 11: 123.[9]Herzig, P. M., Becker, K. P., Stoffers, P. et al., Hydrothermal silica chimney field in the Galapagos rift center at 81°W, Earth Pla. Sci. Lett., 1987, 52: 65.[10] Douthitt, C. B., The geochemistry of the stable isotopes of the silicon, Geochim. Cosmochim. Acta, 1982, 16: 129.[11] Ying Hanlong, Cai Xinping, Liu Bingguang, Geochemical features and formation of auriferous cherts in Mojiang Gold Mine, Yunnan, Geochemistry (in Chinese), 1999

  16. INVESTIGATION OF THIN FILM CADMIUM SULFIDE SOLAR CELLS.

    Science.gov (United States)

    SOLAR CELLS , *CADMIUM COMPOUNDS, FILMS, SULFIDES, VAPOR PLATING, VACUUM APPARATUS, SINGLE CRYSTALS, TITANIUM, COPPER COMPOUNDS, CHLORIDES, INDIUM, MOLYBDENUM, SILICON COMPOUNDS, MONOXIDES, SURFACE PROPERTIES, ENERGY CONVERSION.

  17. Comparative studies of spray pyrolysis deposited copper sulfide nanostructural thin films on glass and FTO coated glass

    Indian Academy of Sciences (India)

    Mehdi Adelifard; Hosein Eshghi; Mohamad Mehdi Bagheri Mohagheghi

    2012-10-01

    CuS thin films with different Cu to S molar ratios (0.33 and 0.43) have been deposited by spray pyrolysis method on glass and FTO coated glass substrates using an aqueous solution of copper (II) acetate and thiourea at a substrate temperature of 285°C. The structural, surface morphological, optical and electrical characterizations of the samples were carried out using XRD, FESEM, UV-Vis and PL spectrophotometer and four-probe apparatus, respectively. X-ray diffraction analysis showed that while the layer/glass sample has an individual CuS (covellite) crystalline phase, the layer/FTO sample includes two additional phases of Cu2S (chalcocite) and Cu1.8S (digenite) as well. Optical measurements showed that all these materials have a relatively high absorption coefficient (∼5 × 104–2.3 × 105 cm-1) in the visible region and direct bandgap of the layers was confirmed with the corresponding room temperature PL spectra. With the resistivity measurements at room and higher temperatures (up to 100°C) confirm that all samples are degenerate in nature with high electrical conductivities of ∼103 (.cm)-1.

  18. 铜离子对葡萄酒发酵中硫化氢产量的影响%Effects of Copper Ions on Hydrogen Sulfide Production in the Fermentation of Grape Wine

    Institute of Scientific and Technical Information of China (English)

    刘富兵; 殷向静; 何娟; 刘延琳

    2012-01-01

    The quantitative determination of the residual S2-concentration in grape wine and the amount of hydrogen sulfide produced in the fermentation process was carried out in the conditions of different copper ions concentration by use of methylene-blue colorimetric method with white rose from Jingyang Shanxi as raw materials.The results suggested that appropriate copper ions concentration(0~0.8 mg/L) in fermenting liquid could inhibit the production of hydrogen sulfide and the best effects could be achieved as the addition level of copper ions was 0.4 mg/L.%以陕西泾阳县的小白玫瑰为材料,根据亚甲基兰比色法,在不同铜离子浓度条件下定量测定发酵过程中产生的硫化氢气体量,以及酒中残留的S2-浓度。结果表明,发酵液中适当浓度的铜离子(0~0.8 mg/L)可以抑制发酵过程中硫化氢气体的生成,当添加0.4 mg/L铜离子浓度时,综合效果最佳。

  19. Replacement of hazardous chromium impregnating agent from silver/copper/chromium-impregnated active carbon using triethylenediamine to remove hydrogen sulfide, trichloromethane, ammonia, and sulfur dioxide.

    Science.gov (United States)

    Wu, Li-Chun; Chung, Ying-Chien

    2009-03-01

    Activated carbon (AC) is widely used as an effective adsorbent in many applications, including industrial-scale air purification systems and air filter systems in gas masks. In general, ACs without chemical impregnation are good adsorbents of organic vapors but poor adsorbents of low-molecular-weight or polar gases such as chlorine, sulfur dioxide (SO2), formaldehyde, and ammonia (NH3). Impregnated ACs modified with metallic impregnating agents (ASC-carbons; e.g., copper, chromium, and silver) enhance the adsorbing properties of the ACs for simultaneously removing specific poisonous gases, but disposal of the chromium metal salt used to impregnate the ACs has the potential to result in situations that are toxic to both humans and the environment, thereby necessitating the search for replaceable organic impregnating agents that represent a much lower risk. The aim of this study was to assess the gas removal efficiency of an AC in which the organic impregnating agent triethylenediamine (TEDA) largely replaced the metallic impregnating agent chromium. We assessed batch and continuous adsorption capacities in situ for removing simulated hydrogen sulfide (H2S), trichloromethane (CHCl3), NH3, and SO2 gases. Brunauer-Emmet-Teller measurements and scanning electron microscopy analyses identified the removal mechanism by which TEDA-impregnated AS-carbon (dechromium ASC-carbon) adsorbs gases and determined the removal capacity for H2S, CHCl3, NH3, and SO2 to be 311, 258, 272, and 223 mg/g-C, respectively. These results demonstrate that TEDA-impregnated AS-carbon is significantly more efficient than ASC-carbon in adsorbing these four gases. Organic TEDA-impregnating agents have also been proven to be a reliable and environmental friendly agent and therefore a safe replacement of the hazardous chromium found in conventional ASC-carbon used in removing toxic gases from the airstream.

  20. Simultaneous ultrasound-assisted ternary adsorption of dyes onto copper-doped zinc sulfide nanoparticles loaded on activated carbon: Optimization by response surface methodology

    Science.gov (United States)

    Asfaram, Arash; Ghaedi, Mehrorang; Hajati, Shaaker; Goudarzi, Alireza; Bazrafshan, Ali Akbar

    2015-06-01

    The simultaneous and competitive ultrasound-assisted removal of Auramine-O (AO), Erythrosine (Er) and Methylene Blue (MB) from aqueous solutions were rapidly performed onto copper-doped zinc sulfide nanoparticles loaded on activated carbon (ZnS:Cu-NP-AC). ZnS:Cu nanoparticles were studied by FESEM, XRD and TEM. First, the effect of pH was optimized in a one-at-a-time procedure. Then the dependency of dyes removal percentage in their ternary solution on the level and magnitude of variables such as sonication time, initial dyes concentrations and adsorbent dosage was fully investigated and optimized by central composite design (CCD) under response surface methodology (RSM) as well as by regarding desirability function (DF) as a good and general criterion. The good agreement found between experimental and predicted values supports and confirms the suitability of the present model to predict adsorption state. The applied ultrasound strongly enhanced mass transfer process and subsequently performance. Hence, a small amount of the adsorbent (0.04 g) was capable to remove high percentage of dyes, i.e. 100%, 99.6% and 100% for MB, AO and Er, respectively, in very short time (2.5 min). The experimental equilibrium data fitting to Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models showed that the Langmuir model applies well for the evaluation and description of the actual behavior of adsorption. The small amount of proposed adsorbent (0.015 g) was applicable for successful removal of dyes (RE > 99.0%) in short time (2.5 min) with high adsorption capacity in single component system (123.5 mg g-1 for MB, 123 mg g-1 for AO and 84.5 mg g-1 for Er). Kinetics evaluation of experiments at various time intervals reveals that adsorption processes can be well predicated and fitted by pseudo-second-order and Elovich models.

  1. Inhibiting Approaches of Magnesium Silicate Minerals in Copper-nickel Sulfide Ore Floatation%铜镍硫化矿浮选中镁质硅酸盐矿物的抑制途径

    Institute of Scientific and Technical Information of China (English)

    曹钊; 张亚辉; 孙传尧; 曹永丹

    2012-01-01

    分析了铜镍硫化矿中MgO脉石矿物的晶体结构、理化性质及其与可浮性的关系,总结了铜镍硫化矿浮选中含镁脉石矿物进入浮选精矿的可能途径及对策,着重介绍了含镁脉石矿物表面活化离子的作用及消除机理,最终得出采用高效金属离子络合剂对矿物表面进行清洗预处理,恢复矿物的原本浮游性,再用选择性抑制剂抑制含镁脉石矿物,将是处理含镁硅酸盐铜镍硫化矿物的有效途径的结论.%The relationship of crystal structure, physico-chemical properties and ftoatability of MgO-containing silicate gangue minerals in copper-nickel sulfide ores was analyzed, possible ways of magnesium silicate mixed into flotation concentrate in copper-nickel sulfids ores flotation and corresponding coun term easu res were summarized, the activating mechanism of metal ions on magnesium silicate and deactivating methods were emphatically researched. Finally an effective method was obtained. In this method, an efficient metal ions complexing agent is used to clean the surfaces of minerals, which will recover their original floatability. In the meantime, a selective depressant is applied to depress magnesium-containing gangue minerals. This may be the effective approach for depressing magnesium-containing silicate minerals in copper-nickel sulfide ore floatation.

  2. Non-toxic and environmentally friendly route for preparation of copper indium sulfide based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sankir, Nurdan Demirci, E-mail: nsankir@etu.edu.tr; Aydin, Erkan; Ugur, Esma; Sankir, Mehmet

    2015-08-15

    Highlights: • Substrate structure of spray pyrolyzed CuInS{sub 2}/In{sub 2}S{sub 3} heterojunction solar cells. • Low cost and environmentally friendly fabrication of CuInS{sub 2} based solar cells. • Low RF power deposition of TCO layer. • AZO–Ag–AZO sandwich structure. • Effect of the thickness of buffer layer on the photovoltaic performance. - Abstract: In this study, copper based thin film solar cells with substrate structure have been built via spray pyrolysis method. Toxic material usage was avoided during the material deposition and the post-treatment steps. Novel device configuration of Mo/CuInS{sub 2}/In{sub 2}S{sub 3}/ZnO/AZO–Ag–AZO was studied as a function of the In{sub 2}S{sub 3} buffer layer thickness. In order to utilize the zinc oxide (ZnO) and aluminum doped zinc oxide (AZO) transparent conductive layers, deposited by physical vapor deposition (PVD), on top of the spray pyrolyzed thin films, the RF power was lowered to 30 W. Although this minimized the unwanted penetration of the highly energetic particles, created during PVD process, sheet resistivity of the AZO films increased enormously. Hence very thin silver layer has been deposited between two AZO films. This resulted the decrease in the sheet resistivity more than 10{sup 6} times. Electrical measurements under illumination revealed that short circuit current density (J{sub sc}), open circuit voltage (V{sub oc}), fill factor (FF) and efficiency (η) of the Mo/CuInS{sub 2}/In{sub 2}S{sub 3}/ZnO/AZO–Ag–AZO type solar cells increased with increasing the thickness of the In{sub 2}S{sub 3} layer. The maximum J{sub sc} of 9.20 mA/cm{sup 2}, V{sub oc} of 0.43 V, FF of 0.44 have been observed for the 0.94 μm-thick In{sub 2}S{sub 3} layer. Extraordinarily thick buffer layer provided better diffusion barrier between the absorber and the TCO layers and also resulted better photosensitivity. These could be the key factors to produce substrate configuration of the spray pyrolyzed

  3. Nanostructured metal sulfides for energy storage.

    Science.gov (United States)

    Rui, Xianhong; Tan, Huiteng; Yan, Qingyu

    2014-09-07

    Advanced electrodes with a high energy density at high power are urgently needed for high-performance energy storage devices, including lithium-ion batteries (LIBs) and supercapacitors (SCs), to fulfil the requirements of future electrochemical power sources for applications such as in hybrid electric/plug-in-hybrid (HEV/PHEV) vehicles. Metal sulfides with unique physical and chemical properties, as well as high specific capacity/capacitance, which are typically multiple times higher than that of the carbon/graphite-based materials, are currently studied as promising electrode materials. However, the implementation of these sulfide electrodes in practical applications is hindered by their inferior rate performance and cycling stability. Nanostructures offering the advantages of high surface-to-volume ratios, favourable transport properties, and high freedom for the volume change upon ion insertion/extraction and other reactions, present an opportunity to build next-generation LIBs and SCs. Thus, the development of novel concepts in material research to achieve new nanostructures paves the way for improved electrochemical performance. Herein, we summarize recent advances in nanostructured metal sulfides, such as iron sulfides, copper sulfides, cobalt sulfides, nickel sulfides, manganese sulfides, molybdenum sulfides, tin sulfides, with zero-, one-, two-, and three-dimensional morphologies for LIB and SC applications. In addition, the recently emerged concept of incorporating conductive matrices, especially graphene, with metal sulfide nanomaterials will also be highlighted. Finally, some remarks are made on the challenges and perspectives for the future development of metal sulfide-based LIB and SC devices.

  4. 从铜铅混浮尾矿中回收锌的研究%Research on recovery zinc sulfide minerals from a tailing of copper-lead bulk flotation

    Institute of Scientific and Technical Information of China (English)

    王国生; 徐晓萍; 高玉德; 黄海威

    2014-01-01

    内蒙某复杂多金属硫化矿含铜、铅、锌、银等有价金属,铜铅混浮的尾矿仍含锌硫.针对铜铅混浮尾矿的矿石性质,采用“锌硫混浮-锌硫分离”的原则流程从铜铅混浮尾矿中回收锌.锌硫混浮时,用硫酸铜作锌矿物的活化剂,用丁黄药作捕收剂,其精选为空白精选;锌硫分离时,添加石灰和适量水玻璃抑制硫化铁矿和石英等硅酸盐脉石.在给矿锌品位为1.55%时,获得锌精矿品位46.30%、回收率90.92%的试验指标,硫得到综合回收.%A tailing was obtained from a Neimeng polymetallic sulfide ore ,which was composed of copper , lead ,zinc ,silver and other valuable metal by copper-lead bulk flotation .It remains to be valuable for the zinc and sulfur .According to the characteristics of tailing ,a process of zinc-sulfur bulk flotation and sepa-ration were used to recovery the zinc .In the zinc-sulfur bulk flotation ,copper sulfate was added as an acti-vator of zinc ,while the sodium butyl xanthate was utilized as a collector of sulfide ore and zinc ,and the lime and sodium silicate as the depressors of sulfide ore .When the feeding contained 1 .55% of zinc ,a Zn concentrate with grade 46 .30% and recovery rate 90 .92% was obtained ,in addition ,the sulfur was com-prehensively recovered as w ell .

  5. 内蒙古某氧硫混合铜矿选矿试验研究%Study on the Beneficiation of a Sulfide - oxidized Copper Ore in Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    贾凤梅; 王林祥; 任大鹏

    2012-01-01

    针对内蒙古氧硫混合铜矿高氧化率、高碱性脉石、高含泥量等特点,着重对控泥、强化活化、强化捕收以及浮选流程进行了系统的研究.在硫酸铵、硫化钠的联合作用下,在捕收剂强化捕收作用下,当磨矿细度-0.074 mm至85%时,采用一次粗选、三次扫选、两次精选、中矿顺序返回的闭路流程,取得了铜精矿品位20.65%、铜回收率85.49%的较好技术指标.%In light of the characteristics of a sulfide - oxidized copper ore in Inner Mongolia, such as high oxidation rate, high alkali gangue, and high content of slime, a systematic study was made for the ore on controlling mud, strengthening activation and collecting. Under the combined action of the ammonium sulfate, sodium sulfide and the action of strengthening collecting, when the percentage of the grinding particle less than 0.074 mm was over 85% , copper concentrate of Cu 20. 65% with a recovery of 85.49% was obtained through the closed circuit process of once roughing, three times scavenging, twain cleaning and middlings returned in order.

  6. 铜粉催化下由碘代芳烃和硫脲合成对称二芳基硫醚的新方法%Synthesis of diaryl sulfide with aryl iodides and thioureas catalyzed by copper powder

    Institute of Scientific and Technical Information of China (English)

    李晓东; 王克虎; 黄丹凤; 牛腾; 胡雨来

    2013-01-01

    The synthesis of diaryl sulfides with aryl iodides and thioureas catalyzed by copper powder in the presence of base and four symmetrical diaryl sulfides were explored. The effect of different base,solvent, temperature and time on the reaction was investigated. The optimum reaction conditions were as follows ;DMSO as solvent,molar ratio of potassium hydroxide to aryl iodides was 2- 1,molar ratio of copper powder to aryl iodides was 1: 10,reaction temperature 130 ℃,reaction time 36 h. This method is easily a-vailable starting material, cheap and stable catalyst, convenient operations, environmentally benign and high yields (85%).%在铜粉催化下,由碘代芳烃和硫脲在碱性条件下反应生成对称二芳基硫醚的新方法,有效合成了4种对称的二芳基硫醚.探索了单质铜粉催化下不同的碱、溶剂、反应温度、反应时间等对反应的影响,经探索得到最佳反应条件为:二甲亚砜作溶剂,氢氧化钾与碘苯的用量比为n(氢氧化钾)∶n(碘苯)=2∶1,铜粉用量与底物碘代芳香烃的摩尔比为n(铜)∶n(碘苯)=1∶10,温度为130 ℃,反应时间36 h.该方法具有原料易得,催化剂价廉稳定,反应操作简便,绿色环保,产率高(可达85%).

  7. 某低品位铜锌矿浮选分离试验研究%Flotation Experimental Study on a Copper-zinc Sulfide Ore

    Institute of Scientific and Technical Information of China (English)

    曹登国; 吴明海

    2014-01-01

    In view of the problem of low grade copper and zinc , the good floatability of zinc mineral and the difficult in separation of copper and zinc in tailings somewhere in Hunan , the test adopted the process of copper -zinc mixed flotation -flotation separation of copper -zinc mixed concen-trate.Copper-zinc flotation separation used lime , zinc sulfate and sodium sulfite as the inhibitors of zinc sulfur minerals , and diethyldithiocarbamate as the collector of copper mineral , which real-ized the effective separation of copper -zinc minerals , as well as the maximum utilization of re-sources .Through closed-circuit experiment the copper concentrate with the grade of 17 .94%and the recovery of 61 .47% and the zinc concentrate with the grade of 45 .43% and the recovery of 59 .73%were obtained respectively .This process provided the technical direction for the reasona -ble development of this type of copper -zinc ore, at the same time put forward the effective recover-y approach of low-grade copper zinc mine of the tailings .%针对湖南某地尾砂中铜、锌品位低,锌矿物可浮性好,铜锌分离难的问题,采用铜锌混合浮选、铜锌分离的工艺流程,以石灰、硫酸锌、亚硫酸钠为锌硫矿物的抑制剂,乙硫氮为铜矿物的捕收剂,实现了铜锌矿物的有效分离,以及资源的最大化利用,闭路试验获得了含 Cu 17.94%、回收率61.47%的铜精矿,含 Zn 45.43%、回收率59.73%的锌精矿,该工艺为合理开发此类铜锌矿提供了技术支持。

  8. Hydrothermal ore-forming processes in the light of studies in rock- buffered systems: I. Iron-copper-zinc-lead sulfide solubility relations

    Science.gov (United States)

    Hemley, J.J.; Cygan, G.L.; Fein, J.B.; Robinson, G.R.; d'Angelo, W. M.

    1992-01-01

    Experimental studies, using cold-seal and extraction vessel techniques, were conducted on Fe, Pb, Zn, and Cu sulfide solubilities in chloride soultions at temperatures from 300?? to 700??C and pressures from 0.5 to 2 kbars. The solutions were buffered in pH by quartz monzonite and the pure potassium feldspar-muscovite-quartz assemblage and in fS2-fO2 largely by the assemblage pyrite-pyrrhotite-magnetite. Solubilities increase with increasing temperature and total chloride, and decrease with increasing pressure. The effect of increasing chloride concentration on solubility reflects primarily a shift to lower pH via the silicate buffer reactions. Similarity in behaviour with respect to the temperature and pressure of Fe, Zn, and Pb sulfide solubilities points to similarity in chloride speciation, and the neutral species appear to be dominant in the high-temperature region. -from Authors

  9. Crystal structure of poly[(μ3-thio-cyanato-κ(3) N:S:S)(tri-methyl-phosphine sulfide-κS)copper(I)].

    Science.gov (United States)

    Corfield, Peter W R

    2014-11-01

    In the title compound, [Cu(NCS)(C3H9PS)] n , the thio-cyanate ions bind the Cu(I) atoms covalently, forming infinite -Cu-SCN-Cu- chains parallel to the a axis. Each Cu(I) atom is also coordinated to a tri-methyl-phosphine sulfide group via a Cu-S bond. Two crystallographically independent chains propagate in opposite directions, and are held together in a ribbon arrangement by long bonds between Cu(I) atoms in the first chain and thio-cyanate S atoms in the second, with Cu-S = 2.621 (1) Å. The geometry around the Cu(I) atoms in the first chain is distorted tetra-hedral, with angles involving the long Cu-S bond much less than ideal, and the S-Cu-N angle between the phosphine sulfide S atom and the thio-cyanate N atom opening out to 133.19 (9)°. Each Cu(I) atom in the second chain appears to be disordered between two positions 0.524 (4) Å apart, with occupancy factors of 0.647 (6) and 0.353 (6). The Cu(I) atom in the major site is in a distorted trigonal-planar configuration, with the S-Cu-N angle between the phosphine sulfide and the thio-cyanate N atom again opened out, to 137.01 (15)°. The Cu(I) atom in the minor site, however, forms in addition a long bond [Cu-S = 2.702 (5) Å] to the phosphine sulfide of the first chain, not the thio-cyanate S atom, to provide a further link between the chains.

  10. 多金属复杂硫化铜矿中有价金属的分离研究现状与进展%Valuable metals extraction from complex multi-metal copper sulfide ore

    Institute of Scientific and Technical Information of China (English)

    周娟; 廖亚龙; 李冰洁; 黄斐荣

    2015-01-01

    综述了复杂铜铅硫化矿中铜锌及铅等有价金属的分离回收技术。通过阐述最近的几种处理复杂硫化铜矿的方法,分析和比较了各处理方法的特点,展望了研究趋势。指出:氧化焙烧预处理-浸出法和硫酸化焙烧-水浸法尽管工艺流程短且简单,但焙烧过程产生的SO2气体对环境污染严重;硫化焙烧-酸浸法能有效降低SO2气体的排放量,但其焙烧条件苛刻,难以实现工业化;高价铁盐浸出法存在高价铁盐损耗大、再生难的问题;使用氯盐体系直接浸出时还存在Cl−对设备腐蚀严重等问题;而氧压浸出和微生物浸出虽然也存在一些不足,但在处理复杂硫化铜矿过程中无有害废气产生,环境友好并且硫以单质硫的形式回收,能有效解决硫酸储存难问题,相信其在今后处理复杂多金属硫化矿中具有广阔的发展前景。%The development of metal extraction from complex sulfide ore containing lead,copper and zinc is reviewed. Several processes for treating complex copper sulfide ore are introduced,and the characteristics of the methods are analyzed and compared. The trend of copper extraction from this kind of ore is also indicated. Although the methods of copper extraction by roasting pretreatment-leaching process,and sulfation roasting-leaching process are simple and straightforward,serious environmental pollution is caused by sulfur dioxide (SO2)emission in these processes. Emission of SO2 can be reduced in the sulfidation roasting-leaching process,but the conditions of the method are demanding and it is difficult to realize industrialization. The method of ferric salts leaching also has lots of problems,such as big loss of leaching agent and difficulty in regeneration of ferric saltsp. The corrosion originated from Cl− limits the application of leaching with ferric chloride. There are also some defects with pressurized oxygen leaching process and bioleaching

  11. Excellent photocatalytic hydrogen production over CdS nanorods via using noble metal-free copper molybdenum sulfide (Cu2MoS4) nanosheets as co-catalysts

    Science.gov (United States)

    Hong, Sangyeob; Kumar, D. Praveen; Reddy, D. Amaranatha; Choi, Jiha; Kim, Tae Kyu

    2017-02-01

    Charge carrier recombination and durability issues are major problems in photocatalytic hydrogen (H2) evolution processes. Thus, there is a very important necessitate to extend an efficient photocatalyst to control charge-carrier dynamics in the photocatalytic system. We have developed copper molybdenum sulfide (Cu2MoS4) nanosheets as co-catalysts with CdS nanorods for controlling charge carriers without recombination for use in photocatalytic H2 evolution under simulated solar light irradiation. Effective control and utilization of charge carriers are possible by loading Cu2MoS4 nanosheets onto the CdS nanorods. The loading compensates for the restrictions of CdS, and stimulated synergistic effects, such as efficient photoexcited charge separation, lead to an improvement in photostability because of the layered structure of the Cu2MoS4nanosheets. These layered Cu2MoS4 nanosheets have emerged as novel and active replacements for precious noble metal co-catalysts in photocatalytic H2 production by water splitting. We have obtained superior H2 production rates by using Cu2MoS4 loaded CdS nanorods. The physicochemical properties of the composites are analyzed by diverse characterization techniques.

  12. Changes induced by gamma radiation in nanocomposites based on copper II and antimony sulfides in commercial poly(methyl methacrylate) matrix; Alteracoes induzidas pela radiacao gama em nanocompositos a base dos sulfetos de cobre II e de antimonio na matriz de poli(metacrilato de metila) comercial

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, M.C.C. de; Garcia, O.P.; Aquino, K.A.S.; Araujo, E.S., E-mail: esa@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2010-07-01

    Poly (methyl methacrylate) (PMMA) is a polymer with wide application in the manufacture of medical devices that is exposed to gamma irradiation. Currently the use of composite materials has been disseminated and PMMA is an excellent polymer matrix to package various materials. This study aimed to analyze the changes induced by gamma irradiation (25 kGy) on the properties of PMMA nanocomposites with nanoparticles of copper II sulfide (250nm-900nm) and antimony sulfite (300-500 nm). The nanoparticles were added to the polymer in different concentrations and synthesized by ultrasonic irradiation from the corresponding chlorides with thioacetamide. Viscometric results showed a good radioprotective effect of nanoparticles of copper and antimony. It was found a good protection of nanoparticles on PMMA matrix in the concentration of 0.3% wt. The protections of 75% and 50% were calculated for nanoparticles of antimony and copper II, respectively. (author)

  13. Zeta Potential Study on the Bio-oxidation of Copper Sulfide Minerals%硫化铜矿细菌氧化的Zeta电位研究

    Institute of Scientific and Technical Information of China (English)

    傅开彬; 林海

    2012-01-01

    为了研究矿物与细菌相互作用后矿物的Zeta电位与细菌对矿物的氧化能力之间的关系,利用Zeta电位仪检测与细菌作用前后硫化矿的Zeta电位,根据Zeta电位和IEP(Iso Electric Point)的变化,判断细菌对硫化矿的氧化作用及其程度。结果表明,硫化铜矿与细菌作用后,矿物的Zeta电位降低,辉铜矿、斑铜矿和铜蓝的IEP向铜的氢氧化物方向移动,而黄铜矿向细菌的IEP方向靠近,分析原因主要是由于各矿物被细菌氧化的程度不同。对与细菌相互作用后的铜蓝进行XPS测试结果证实其表面被氧化。研究证实了细菌对硫化矿的直接氧化作用,同时也得出不同硫化铜的细菌氧化顺序:辉铜矿〉斑铜矿〉铜蓝〉黄铜矿。%The direct bacterial oxidation of sulphide minerals was evaluated by Zeta potential and the iso- electric point (IEP). The results show that copper sulphide minerals have been directly oxidized by the bacteria, after conditioning with Acidithiobacillus ferrooxidans, the Zeta potential of copper sulphide de- creased and became negative, the IEP of chalcoeite, bornite and covellite moved towards the IEP of cop- per hydroxide, however, the IEP of chalcopyrite was very close to that of bacteria. The XPS of covellite after conditioning with bacteria indicates the surface was oxidized. The results support the direct mecha- nism of sulphide minerals bio-oxidation from a new viewpoint. The following order for the bio-oxidation of these minerals is obtained ~ chalcocite 〉 bornite 〉 covellite 〉 chalcoovrite.

  14. [Serum cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE ) and cytochrome c oxidase (COX) in copper mine miners potentially expose d to hydrogen sulfide].

    Science.gov (United States)

    Skoczyńska, Anna; Gruszczyński, Leszek; Turczyn, Barbara; Ścieszka, Marek; Wojakowska, Anna; Pawłowski, Tomasz; Schmidt, Edward

    2015-01-01

    The aim of the study was to evaluate serum levels of the target enzyme for H2S toxicity--cytochrome c oxidase (COX) and enzymes involved in the synthesis of H2S--cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) in copper mine miners. The initial and basic study was conducted respectively in 237 and 88 miners, working in 2 mining shafts: I--no H2S emissions recorded in the last 10 years (study group A) and II--H2S emissions occurred (study group B). A medical examination was performed and 10 ml of blood was collected from miners immediately after exiting the mine. There were no clinical or biochemical changes typical for H2S toxicity. Sulfhemoglobine was undetectable and there were no changes in the red-ox system. However, in group B, regulatory changes were found; a tendency to higher concentration of CBS and CSE, a higher activity of angiotensin converting enzyme (ACE) compared to group A (pCBS and CSE activity. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  15. Temporal and spatial distribution of alteration, mineralization and fluid inclusions in the transitional high-sulfidation epithermal-porphyry copper system at Red Mountain, Arizona

    Science.gov (United States)

    Lecumberri-Sanchez, Pilar; Newton, M. Claiborne; Westman, Erik C.; Kamilli, Robert J.; Canby, Vertrees M.; Bodnar, Robert J.

    2013-01-01

    Red Mountain, Arizona, is a Laramide porphyry Cu system (PCD) that has experienced only a modest level of erosion compared to most other similar deposits in the southwestern United States. As a result, the upper portion of the magmatic–hydrothermal system, which represents the transition from shallower high-sulfidation epithermal mineralization to deeper porphyry Cu mineralization, is well preserved. Within the Red Mountain system, alteration, mineralization and fluid inclusion assemblages show a systematic distribution in both time and space. Early-potassic alteration (characterized by the minerals biotite and magnetite) is paragenetically earlier than late-potassic alteration (K-feldspar–anhydrite) and both are followed by later phyllic (sericite–pyrite) alteration. Advanced argillic alteration (pyrophyllite–alunite–other clay minerals) is thought to be coeval with or postdate phyllic alteration. Minerals characteristic of advanced argillic alteration are present in the near surface. Phyllic alteration extends to greater depths compared to advanced argillic alteration. Early-potassic and late-potassic alteration are only observed in the deepest part of the system. Considerable overlap of phyllic alteration with both early-potassic and late-potassic alteration zones is observed. The hypogene mineralization contains 0.4–1.2% Cu and is spatially and temporally related to the late-potassic alteration event. Molybdenum concentration is typically In the deepest part of the system, an early generation of low-to-moderate density and salinity liquid + vapor inclusions with opaque daughter minerals is followed in time by halite-bearing inclusions that also contain opaque daughter minerals indicating that an early intermediate-density magmatic fluid evolved to a high-density, high-salinity mineralizing fluid. The increase in density and salinity of fluids with time observed in the deeper parts of the system may be the result of immiscibility (“boiling”) of

  16. Trace element distribution, with a focus on gold, in copper-rich and zinc-rich sulfide chimneys from Brothers submarine volcano, Kermadec arc

    Science.gov (United States)

    Berkenbosch, H. A.; de Ronde, C. E.; McNeill, A.; Goemann, K.; Gemmell, J. B.

    2012-12-01

    Brothers volcano is a dacitic volcano located along the Kermadec arc, New Zealand, and hosts the NW Caldera hydrothermal vent field perched on part of the steep caldera walls. The field strikes for ~600 m between depths of 1550 and 1700 m and includes numerous, active, high-temperature (max 302°C) chimneys and even more dead, sulfide-rich spires. Chimney samples collected from Brothers show distinct mineralogical zonation reflecting gradients in oxidation state, temperature, and pH from the inner walls in contact with hydrothermal fluids through to the outer walls in contact with seawater. Minerals deposited from hotter fluids (e.g., chalcopyrite) are located in the interior of the chimneys and are surrounded by an external zone of minerals deposited by cooler fluids (e.g., sulfates, sphalerite). Four chimneys types are identified at Brothers volcano based on the relative proportions of chalcopyrite and sulfate layers, and the presence or absence of anhydrite. Two are Cu-rich, i.e., chalcopyrite-rich and chalcopyrite-bornite-rich chimneys, and two are Zn-rich, i.e., sphalerite-rich and sphalerite-chalcopyrite-rich. Barite and anhydrite are common to both Cu-rich chimney types whereas Zn-rich chimneys contain barite only. The main mineral phases in all the chimneys are anhydrite, barite, chalcopyrite, pyrite/marcasite, and sphalerite. Trace minerals include galena, covellite, tennantite, realgar, chalcocite, bornite, hematite, goethite, Pb-As sulfosalts, and Bi- or Au-tellurides. The vast majority of tellurides are vent site. These tellurides are the first gold-bearing phase to be identified in these chimneys, and the Bi-Au association suggests that gold-enrichment up to 91 ppm is due to scavenging by liquid bismuth. To better understand the mineral associations and zonation of these and other trace elements within the chimney walls, we have undertaken element mapping on the four different chimneys types with both X-Ray fluorescence microscopy using synchrotron

  17. Serum cystathionine β-synthase (CBS, cystathionine γ-lyase (CSE and cytochrome c oxidase (COX in copper mine miners potentially expose d to hydrogen sulfide

    Directory of Open Access Journals (Sweden)

    Anna Skoczyńska

    2015-08-01

    Full Text Available Background: The aim of the study was to evaluate serum levels of the target enzyme for H2S toxicity – cytochrome c oxidase (COX and enzymes involved in the synthesis of H2S – cystathionine β-synthase (CBS and cystathionine γ-lyase (CSE in copper mine miners. Material and Methods: The initial and basic study was conducted respectively in 237 and 88 miners, working in 2 mining shafts: I – no H2S emissions recorded in the last 10 years (study group A and II – H2S emissions occurred (study group B. A medical examination was performed and 10 ml of blood was collected from miners immediately after exiting the mine. Results: There were no clinical or biochemical changes typical for H2S toxicity. Sulfhemoglobine was undetectable and there were no changes in the red-ox system. However, in group B, regulatory changes were found; a tendency to higher concentration of CBS and CSE, a higher activity of angiotensin converting enzyme (ACE compared to group A (p < 0.05 and a linear relationship between ACE and CSE (r = 0.6927; p < 0.001. It has been shown that cigarette smoking decreases COX (p < 0.05, however, in miners working in shaft II, the decreased level of COX may result also from the presence of H2S in the gaseous emissions. Conclusions: COX concentration can be a sensitive indicator of exposure to H2S. The measurements of blood H2S concentrations carried out in workplaces should explain the cause of the changes observed in the COX, CBS and CSE activity. Med Pr 2015;66(4:539–548

  18. Studies on ternary and quaternary copper, lithium and silver sulfides with a diamond structure; Untersuchungen an ternaeren und quaternaeren Kupfer-, Lithium-, und Silbersulfiden mit Diamantstruktur

    Energy Technology Data Exchange (ETDEWEB)

    Greil, Sebastian

    2015-04-09

    Within this work new attempts have been done to prepare unknown compounds in the field of quaternary tetrahedral compounds. Therefore it was tried to synthesize compounds of the composition A{sup I}{sub 2}M{sup II}M{sup IV}S{sub 4} with A = Ag, Li, M{sup II} = Fe, Co, Mn, Hg, Cd, Zn, Pb, MIV = Si, Ge, Sn, which are not known in the literature so far. For these compositions the known copper compounds were used as a model. Using this route, the new compounds Ag{sub 2}MnSnS{sub 4}, Ag{sub 2}FeGeS{sub 4}, Li{sub 2}MnSnS{sub 4} and Li{sub 2}FeSnS{sub 4} were synthesized. All of the mentioned compounds except Ag{sub 2}FeGeS{sub 4}, that crystallizes tetragonal, crystallize in the wurtzite-type. The predicted anti-ferromagnetism for Ag{sub 2}MnSnS{sub 4} mentioned in the literature could not be confirmed. Furthermore it was attempted to synthesize new compounds containing titanium, zirconium and hafnium as tetravalent cation that resulted in the compound Cu{sub 2}ZrS{sub 3} which was not known in the literature before. Additionally, the compounds Cu{sub 10}Cd{sub 2}As{sub 4}S{sub 13} and Cu{sub 10}Mn{sub 2}As{sub 4}S{sub 13} were prepared, which could be derived from Cu{sub 12}As{sub 4}S{sub 13}.

  19. The Advances of Copper Sulfide Nanoparticles for Cancer Diagnosis and Therapy%硫化铜纳米粒子应用于肿瘤诊断和治疗的研究进展

    Institute of Scientific and Technical Information of China (English)

    张书海; 查正宝; 骆三

    2014-01-01

    癌症是当今威胁人类健康的主要疾病之一.近年来提出的近红外光介导的光热治疗,能够对肿瘤组织进行定点清除并且对正常组织具有较低的毒副作用,为肿瘤的治疗提供了新的方法.开发具有良好生物相容性的高效光热偶联剂是发展光热治疗的首要条件.随着纳米技术的飞速发展,一些金属纳米结构由于具有独特的光学特性作为光热偶联剂被广泛应用到肿瘤的光热治疗中.然而,成本高昂、制备过程繁琐以及光热稳定性较差等不足,限制了这些纳米材料的进一步应用.最新报道的新型光热偶联剂半导体硫化铜纳米粒子(copper sulfide nanoparticles,CuS NPs),由于其具有制备工艺简单、成本低廉、突出的光热稳定性和良好的生物相容性等优势,成为了当今纳米医学领域研究的热点.本文主要综述了CuS纳米粒子在肿瘤光热治疗和影像诊断方面的应用研究,并对CuS纳米粒子在生物医学领域应用中存在的问题和未来的研究方向进行了展望.

  20. Contrast of pyro-metallurgy and hydro-metallurgy processes of one high copper content refractory sulfide gold concentrate%某高铜难处理硫化金精矿火法冶炼与湿法冶炼工艺对比

    Institute of Scientific and Technical Information of China (English)

    樊蕾; 梁可; 张春生; 张之于; 张岚

    2016-01-01

    为获得某高铜难处理硫化金精矿的最佳处理方案,根据其金精矿性质,进行了火法冶炼与湿法冶炼工艺的对比分析. 其结果表明:对于该高铜硫化金精矿,火法冶炼工艺优于湿法冶炼工艺,其能更好地回收精矿中的 Cu、Au、Ag,实现了矿产资源的综合利用,也可获得较好的经济效益.%Pyro-metallurgy and hydro-metallurgy processes are compared according to the properties of gold con-centrates to obtain the optimal treatment plan of one high copper content refractory sulfide gold concentrate. The study finds that for the gold concentrates,pyro-metallurgy process is better than hydro-metallurgy. It can better recover Cu, Au and Ag from high copper content refractory sulfide gold concentrates fulfilling the purpose of comprehensive recov-ery and obtaining satisfactory economic profits.

  1. Volcanogenic massive sulfide occurrence model: Chapter C in Mineral deposit models for resource assessment

    Science.gov (United States)

    Shanks, W.C. Pat; Koski, Randolph A.; Mosier, Dan L.; Schulz, Klaus J.; Morgan, Lisa A.; Slack, John F.; Ridley, W. Ian; Dusel-Bacon, Cynthia; Seal, Robert R., II; Piatak, Nadine M.; Shanks, W.C. Pat; Thurston, Roland

    2012-01-01

    Volcanogenic massive sulfide deposits, also known as volcanic-hosted massive sulfide, volcanic-associated massive sulfide, or seafloor massive sulfide deposits, are important sources of copper, zinc, lead, gold, and silver (Cu, Zn, Pb, Au, and Ag). These deposits form at or near the seafloor where circulating hydrothermal fluids driven by magmatic heat are quenched through mixing with bottom waters or porewaters in near-seafloor lithologies. Massive sulfide lenses vary widely in shape and size and may be podlike or sheetlike. They are generally stratiform and may occur as multiple lenses.

  2. ANALYSIS OF EFFECTIVE APPROACHES FOR DEPRESSING MgO-CONTAINING GANGUE MINERALS IN COPPER-NICKEL SULFIDE ORE FLOATATION%铜镍硫化矿浮选过程中MgO脉石矿物的抑制途径探析

    Institute of Scientific and Technical Information of China (English)

    张亚辉; 孟凡东; 孙传尧

    2012-01-01

    Nickel ore resources in China are mostly low-grade copper-nickel sulfide ores with high percentage of MgO-containing silicate gangue minerals. Major copper-nickel mines in China, such as Jinchuan Group Ltd. , have been striving to lower the magnesium content of floatation concentrate. Although lots of researches have been done, the depressing of MgO-containing gangue minerals in copper-nickel sulfide ore floatation is not technically controllable. Related literatures on depressing of MgO-conVaining gangue minerals have been reviewed. It is suggested that highly effective composite depressant, that is, a completing agent - depressant combination, should be employed to depress MgO-containing silicate gangue minerals. A complexing agent is used to clean the surfaces of valuable minerals and gangue minerals, which will increase their floatability difference. In the meantime, a selective depressant is applied to depress MgO-containing gangue minerals. This will be the effective approach for depressing MgO-containing silicate minerals in copper-nickel sulfide ore floatation.%我国镍矿石资源主要为富含MgO硅酸盐脉石矿物的低品位铜镍硫化矿.长期以来,以金川公司为代表的主要铜镍矿山,一直将浮选精矿降镁作为选矿技术攻关的重点.尽管国内外研究人员开展了大量的研究工作,铜镍硫化矿浮选过程中MgO脉石矿物的抑制至今未能在技术上找到可控的解决方法.文章对MgO脉石矿物抑制研究的相关文献进行了综述分析,提出采用复合抑制剂,即络合剂-抑制剂组合,先对有用矿物和脉石矿物进行表面清洗以扩大其可浮性差异,再选择性抑制MgO脉石矿物,这将是铜镍硫化矿浮选过程中抑制MgO硅酸盐脉石矿物的有效途径.

  3. Artificial Corrosion of Cu-Alloys. A Contribution to Understanding Microbial and Nonmicrobial Sulfide Corrosion.

    Science.gov (United States)

    1992-01-01

    therefore, the dominant reduced sulfur species considered in this paper. Conditions of Mineral Formation Figures 14 and 15 show the stability fields...would have been reduced to < 2 ppm in the first week. Although such low sulfide levels are not conducive to Cu-S mineral formation , copper sulfide

  4. 常温下用直接沉淀法制备纳米硫化铜%Preparation of copper sulfide nanoparticles by direct precipitation method at normal temperature

    Institute of Scientific and Technical Information of China (English)

    王伟力; 王桂清

    2012-01-01

    在常温下以硫酸铜( CuSO4·5H 2O)为铜源,硫化钠(Na2S ·9H2O)为硫源,六偏磷酸钠(NaPO3)6为稳定剂,辛基酚聚氧乙烯醚(OP-10)为表面活性剂,采用沉淀法成功合成了硫化铜纳米晶体;利用X射线粉末衍射仪和高分辨透射电镜分析了产物的晶体结构和形貌,考察了反应体系的pH、温度、反应物浓度、稳定剂用量等对产物组成和结构的影响.此外,利用紫外-可见光谱仪、荧光光谱仪及傅立叶转换红外光谱仪分析了产物的光学性质.结果表明,产物为纯六方相的硫化铜;其颗粒呈不规则球型、椭球型、棒状,平均粒径约为37 nm.产物在200~230 nm波长范围内对紫外光有较强的吸收;用383 nm的光激发,分别在440 nm和486 nm出现两个荧光发射峰,与常规硫化铜相比发生明显的蓝移.此外,产物具有良好的红外光透过率;反应体系的pH对产物的带隙能E(g)和光致发光强度有明显的影响.%Copper sulfide (CuS) nanoparticles were prepared by direct precipitation method at 25 ℃ using CuSO4 as Cu-precursor, Na2S as S-source, sodium hexametaphosphate (NaPO3)6 as stabilizing agent, and polyoxyethylene octylphenol ether (OP-10) as surfactant. The crystalline structure and morphology of as-prepared product were analyzed by means of powder X-ray diffraction and high-resolution transmission electron microscopy, and the effects of pH and temperature of reaction system, reactant concentration, and dosage of stabilizer on the phase structure and morphology of the product were investigated. Moreover, the spectrometric properties of the product were evaluated using an ultraviolet-visible light spectrometer. It has been found that as-prepared CuS nanoparticles are of pure hexagonal phase, and they appear as irregularly-shaped spheres, elliptical spheres and bars with an average size of 37 nm. The optical properties of the product were detected with an ultraviolet-visible light absorption spectrometer

  5. Synthesis and photovoltaic application of coper (I) sulfide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue; Wadia, Cyrus; Ma, Wanli; Sadtler, Bryce; Alivisatos, A.Paul

    2008-06-24

    We present the rational synthesis of colloidal copper(I) sulfide nanocrystals and demonstrate their application as an active light absorbing component in combination with CdS nanorods to make a solution-processed solar cell with 1.6percent power conversion efficiency on both conventional glass substrates and flexible plastic substrates with stability over a 4 month testing period.

  6. Sulfide Mineralogy and Geochemistry

    Science.gov (United States)

    Dilles, John

    2007-02-01

    Reviews in Mineralogy and Geochemistry Series, Volume 61 David J. Vaughan, Editor Geochemical Society and Mineralogical Society of America; ISBN 0-939950-73-1 xiii + 714 pp.; 2006; $40. Sulfide minerals as a class represent important minor rock-forming minerals, but they are generally known as the chief sources of many economic metallic ores. In the past two decades, sulfide research has been extended to include important roles in environmental geology of sulfide weathering and resultant acid mine drainage, as well as in geomicrobiology in which bacteria make use of sulfides for metabolic energy sources. In the latter respect, sulfides played an important role in early evolution of life on Earth and in geochemical cycling of elements in the Earth's crust and hydrosphere.

  7. Platinum metals in magmatic sulfide ores

    Science.gov (United States)

    Naldrett, A.J.; Duke, J.M.

    1980-01-01

    Platinum-group elements (PGE) are mined predominantly from deposits that have formed by the segregation of molten iron-nickel-copper sulfides from silicate magmas. The absolute concentrations of PGE in sulfides from different deposits vary over a range of five orders of magnitude, whereas those of other chalcophile elements vary by factors of only 2 to 100. However, the relative proportions of the different PGE in a given deposit are systematically related to the nature of the parent magma. The absolute and relative concentrations of PGE in magmatic sulfides are explained in terms of the degree of partial melting of mantle peridotite required to produce the parent magma and the processes of batch equilibration and fractional segregation of sulfides. The Republic of South Africa and the U.S.S.R. together possess more than 97 percent of the world PGE reserves, but significant undeveloped resources occur in North America. The Stillwater complex in Montana is perhaps the most important example. Copyright ?? 1980 AAAS.

  8. Nanomaterials made of non-toxic metallic sulfides: A systematic review of their potential biomedical applications.

    Science.gov (United States)

    Argueta-Figueroa, Liliana; Martínez-Alvarez, O; Santos-Cruz, J; Garcia-Contreras, R; Acosta-Torres, L S; de la Fuente-Hernández, J; Arenas-Arrocena, M C

    2017-07-01

    Metallic sulfides involve the chemical bonding of one or more sulfur atoms to a metal. Metallic sulfides are cheap, abundant semiconductor materials that can be used for several applications. However, an important and emerging use for non-toxic metallic sulfides in biomedical applications has arisen quickly in the medical field. In this systematic review, the available data from electronic databases were collected according to PRISMA alignments for systematic reviews. This review shows that these metallic sulfides could be promising for biomedical uses and applications. This systematic review is focused primarily on the following compounds: silver sulfide, copper sulfide, and iron sulfide. The aim of this review was to provide a quick reference on synthesis methods, biocompatibility, recent advances and perspectives, with remarks on future improvements. The toxicity of metallic sulfides depends directly on the cytotoxicity of their interactions with cells and tissues. Metallic sulfides have potential biomedical applications due to their antibacterial properties, uses in imaging and diagnostics, therapies such as photothermal therapy and chemotherapy in tumors and cancer cells, drug delivery and the fabrication of biosensors for the sensitive and selective detection of moieties, among others. Although current evidence about metallic sulfide NPs is promising, there are still several issues to be addressed before these NPs can be used in biomedicine. The current review is a brief but significant guide to metallic sulfides and their potential uses in the biomedical field. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Determination of Ruthenium, Rhodium, Palladium, Iridium and Platinum in Copper-Nickel Sulfide Ores by Bismuth-Antimony Fire Assay%铋锑试金测定硫化铜镍矿中钌铑钯铱铂

    Institute of Scientific and Technical Information of China (English)

    李可及; 刘淑君; 邵坤

    2014-01-01

    建立了用于预富集硫化铜镍矿中钌铑钯铱铂5种铂族元素的铋锑试金方法。40.0 g 氧化铋、25.0 g硼酸、10.0 g 碳酸钠、1.00 g 淀粉与10.0 g 待测样品于120 mL 瓷皿中,充分混匀,850℃入炉,20 min 后升至1000℃,保留40 min,出炉后趁热倾倒熔渣,使铋试金于空气中自然冷却。设计两段灰吹流程,铋试金先在镁砂灰皿内灰吹,直至剩余直径约5 mm,而后直接转入盛有20 g 熔融锑粉的坩埚盖中继续灰吹,获得直径约1 mm 的试金合粒。所得合粒经微波消解,冷却后定容至10 mL。铂钯用 ICP-OES 分析;钌铑铱质量数选择99 Ru,103 Rh 和191 Ir,以115 In 和185 Re 为内标,应用 ICP-MS 分析。对标准物质 GBW07196平行测定12次,铂族元素相对标准偏差为7.0%~9.5%。在10 g 取样量条件下,方法对 Ru, Rh, Pd, Ir 和 Pt 的检出限分别为0.027,0.016,0.11,0.10和0.11 ng/ g。应用本方法处理标准物质 GBW07194,GBW07195和 GBW07196均获得了满意的结果。%A bismuth-antimony fire assay method for the preconcentration of ruthenium, rhodium, palladium, iridium and platinum in copper-nickel sulfide ores was developed. 40. 0 g bismuth trioxide, 25. 0 g boric acid, 10. 0 g sodium carbonate and 1. 00 g starch were mixed with 10. 0 g sample in a 120 mL porcelain bowl, which was put in a furnace at 850 ℃. After 20 min the temperature was raised to 1000 ℃ and held for another 40 min, and then the bowl was taken out, with the slag poured, which left the bismuth button to air cooling. A two-step cupellation procedure was developed. During the first step, the bismuth button was cupellated in a magnesia cupel until its diameter reached 5 mm or so, then it was transferred to a crucible cover containing 20 g melting antimony and kept cupellating, at last a bead with a diameter of 1 mm was obtained. The bead was microwave-digested, after cooling down to room temperature, the solvent of which was transferred to a volumetric flask and

  10. Direct Production of Copper

    Science.gov (United States)

    Victorovich, G. S.; Bell, M. C.; Diaz, C. M.; Bell, J. A. E.

    1987-09-01

    The use of commercially pure oxygen in flash smelting a typical chalcopyrite concentrate or a low grade comminuted matte directly to copper produces a large excess of heat. The heat balance is controlled by adjusting the calorific value of the solid feed. A portion of the sulfide material is roasted to produce a calcine which is blended with unroasted material, and the blend is then autogeneously smelted with oxygen and flux directly to copper. Either iron silicate or iron calcareous slags are produced, both being subject to a slag cleaning treatment. Practically all of the sulfur is contained in a continuous stream of SO2 gas, most of which is strong enough for liquefaction. A particularly attractive feature of these technologies is that no radically new metallurgical equipment needs to be developed. The oxygen smelting can be carried out not only in the Inco type flash furnace but in other suitable smelters such as cyclone furnaces. Another major advantage stems from abolishion of the ever-troublesome converter aisle, which is replaced with continuous roasting of a fraction of the copper sulfide feed.

  11. Soft chemical control of the crystal and magnetic structure of a layered mixed valent manganite oxide sulfide

    Directory of Open Access Journals (Sweden)

    Jack N. Blandy

    2015-04-01

    Full Text Available Oxidative deintercalation of copper ions from the sulfide layers of the layered mixed-valent manganite oxide sulfide Sr2MnO2Cu1.5S2 results in control of the copper-vacancy modulated superstructure and the ordered arrangement of magnetic moments carried by the manganese ions. This soft chemistry enables control of the structures and properties of these complex materials which complement mixed-valent perovskite and perovskite-related transition metal oxides.

  12. Energy and materials flows in the copper industry

    Energy Technology Data Exchange (ETDEWEB)

    Gaines, L.L.

    1980-12-01

    The copper industry comprises both the primary copper industry, which produces 99.9%-pure copper from copper ore, and the secondary copper industry, which salvages and recycles copper-containing scrap metal to extract pure copper or copper alloys. The United States uses about 2 million tons of copper annually, 60% of it for electrical applications. Demand is expected to increase less than 4% annually for the next 20 years. The primary copper industry is concentrated in the Southwest; Arizona produced 66% of the 1979 total ore output. Primary production uses about 170 x 10/sup 12/ Btu total energy annually (about 100 x 10/sup 6/ Btu/ton pure copper produced from ore). Mining and milling use about 60% of the total consumption, because low-grade ore (0.6% copper) is now being mined. Most copper is extracted by smelting sulfide ores, with concomitant production of sulfur dioxide. Clean air regulations will require smelters to reduce sulfur emissions, necessitating smelting process modifications that could also save 20 x 10/sup 12/ Btu (10 x 10/sup 6/ Btu/ton of copper) in smelting energy. Energy use in secondary copper production averages 20 x 10/sup 6/ Btu/ton of copper. If all copper products were recycled, instead of the 30% now salvaged, the energy conservation potential would be about one-half the total energy consumption of the primary copper industry.

  13. Energy and materials flows in the copper industry

    Energy Technology Data Exchange (ETDEWEB)

    Gaines, L.L.

    1980-12-01

    The copper industry comprises both the primary copper industry, which produces 99.9%-pure copper from copper ore, and the secondary copper industry, which salvages and recycles copper-containing scrap metal to extract pure copper or copper alloys. The United States uses about 2 million tons of copper annually, 60% of it for electrical applications. Demand is expected to increase less than 4% annually for the next 20 years. The primary copper industry is concentrated in the Southwest; Arizona produced 66% of the 1979 total ore output. Primary production uses about 170 x 10/sup 12/ Btu total energy annually (about 100 x 10/sup 6/ Btu/ton pure copper produced from ore). Mining and milling use about 60% of the total consumption, because low-grade ore (0.6% copper) is now being mined. Most copper is extracted by smelting sulfide ores, with concomitant production of sulfur dioxide. Clean air regulations will require smelters to reduce sulfur emissions, necessitating smelting process modifications that could also save 20 x 10/sup 12/ Btu (10 x 10/sup 6/ Btu/ton of copper) in smelting energy. Energy use in secondary copper production averages 20 x 10/sup 6/ Btu/ton of copper. If all copper products were recycled, instead of the 30% now salvaged, the energy conservation potential would be about one-half the total energy consumption of the primary copper industry.

  14. Reducing the Content of Fluorine and Magnesium in a Copper Sulfide Concentrate in Anhui Province Using the Inhibitor DG11%用抑制剂DG11降低安徽某硫化铜精矿氟镁含量

    Institute of Scientific and Technical Information of China (English)

    李汉文; 王晨亮; 胡真; 李沛伦

    2016-01-01

    安徽某硫化铜矿选矿厂铜精矿铜品位为18.20%,F、MgO含量分别为0.25%和9.26%,不仅铜品位偏低,且F、MgO含量不满足冶炼厂对铜精矿F含量小于0.1%、MgO含量小于5%的要求。研究查明,含F、MgO易泥化、易浮滑石、蛇纹石和绿泥石等以微细粒大量混杂进入铜精矿是造成现场铜精矿F、MgO含量超标的主要原因。以广东省资源综合利用研究所研发的DG11为含氟镁脉石矿物的抑制剂,采用1粗1精1扫、中矿顺序返回浮选流程处理现场铜精矿,最终获得了铜品位为25.11%、铜回收率为97.45%,F和MgO含量分别为0.082%和2.02%的铜精矿,既显著提高了精矿铜品位,又大幅度降低了精矿氟、镁含量,达到冶炼厂对铜精矿F和MgO含量的要求。%The copper concentrate products of a sulfide copper ore dressing plant in Anhui province containing 18.20%Cu,0.25% F,9.26% MgO.Not only the copper grade is low,but also the content of fluorine and magnesium exceeds the standard of the smelting plant requires (content of F<0.1%,content of MgO<5%).Studies have shown that easy mudding and easy floating talc,serpentine and chlorite exist in the form of fine particles,these minerals containing F,MgO and in large mixed into the copper concentrate,which is the main cause of fluoride,magnesium content in on-site copper concentrate ex-ceeds the standard.Using DG1 1 developed by Guangdong Institute of Resources Comprehensive Utilization as inhibitor of the gangue minerals which contain fluorine and magnesium.Through the process of one roughing-one cleaning-one scavenging,and middling returning in proper order into the flow,the results show that the copper concentrate have 25.1 1%grade and 97.45%recovery rate,including 0.082% F,2.02%MgO.It not only improves the grade of copper concentrate,but also greatly reduces the content of fluorine and magnesium in the concentrate,and reached the requirements of copper smelting

  15. Interstellar hydrogen sulfide.

    Science.gov (United States)

    Thaddeus, P.; Kutner, M. L.; Penzias, A. A.; Wilson, R. W.; Jefferts, K. B.

    1972-01-01

    Hydrogen sulfide has been detected in seven Galactic sources by observation of a single line corresponding to the rotational transition from the 1(sub 10) to the 1(sub 01) levels at 168.7 GHz. The observations show that hydrogen sulfide is only a moderately common interstellar molecule comparable in abundance to H2CO and CS, but somewhat less abundant than HCN and much less abundant than CO.

  16. Mineral formation on metallic copper in a `future repository site environment`

    Energy Technology Data Exchange (ETDEWEB)

    Amcoff, Oe.; Holenyi, K.

    1996-04-01

    Since reducing conditions are expected much effort has been concentrated on Cu-sulfides and CuFe-sulfides. However, oxidizing conditions are also discussed. A list of copper minerals are included. It is concluded that mineral formation and mineral transitions on the copper canister surface will be governed by kinetics and metastabilities rather than by stability relations. The sulfides formed are less likely to form a passivating layer, and the rate of sulfide growth will probably be governed by the rate of transport of reacting species to the canister surface. A series of tests are recommended, in an environment resembling the initial repository site conditions. 82 refs, 8 figs.

  17. Sulfide oxidation in a biofilter

    DEFF Research Database (Denmark)

    Pedersen, Claus Lunde; Dezhao, Liu; Hansen, Michael Jørgen;

    Observed hydrogen sulfide uptake rates in a biofilter treating waste air from a pig farm were too high to be explained within conventional limits of sulfide solubility, diffusion in a biofilm and bacterial metabolism. Clone libraries of 16S and 18S rRNA genes from the biofilter found no sulfide o...... higher hydrogen sulfide uptake followed by oxidation catalyzed by iron-containing enzymes such as cytochrome c oxidase in a process uncoupled from energy conservation....

  18. Sulfide oxidation in a biofilter

    DEFF Research Database (Denmark)

    Pedersen, Claus Lunde; Liu, Dezhao; Hansen, Michael Jørgen;

    2012-01-01

    Observed hydrogen sulfide uptake rates in a biofilter treating waste air from a pig farm were too high to be explained within conventional limits of sulfide solubility, diffusion in a biofilm and bacterial metabolism. Clone libraries of 16S and 18S rRNA genes from the biofilter found no sulfide o...... higher hydrogen sulfide uptake followed by oxidation catalyzed by iron-containing enzymes such as cytochrome c oxidase in a process uncoupled from energy conservation....

  19. Enhanced sulfidation xanthate flotation of malachite using ammonium ions as activator.

    Science.gov (United States)

    Wu, Dandan; Ma, Wenhui; Mao, Yingbo; Deng, Jiushuai; Wen, Shuming

    2017-05-18

    In this study, ammonium ion was used to enhance the sulfidation flotation of malachite. The effect of ammonium ion on the sulfidation flotation of malachite was investigated using microflotation test, inductively coupled plasma (ICP) analysis, zeta potential measurements, and scanning electron microscope analysis (SEM). The results of microflotation test show that the addition of sodium sulfide and ammonium sulfate resulted in better sulfidation than the addition of sodium sulfide alone. The results of ICP analysis indicate that the dissolution of enhanced sulfurized malachite surface is significantly decreased. Zeta potential measurements indicate that a smaller isoelectric point value and a large number of copper-sulfide films formed on the malachite surface by enhancing sulfidation resulted in a large amount of sodium butyl xanthate absorbed onto the enhanced sulfurized malachite surface. EDS semi-quantitative analysis and XPS analysis show that malachite was easily sulfurized by sodium sulfide with ammonium ion. These results show that the addition of ammonium ion plays a significant role in the sulfidation of malachite and results in improved flotation performance.

  20. 刚果(金)某硫化铜钴精矿沸腾焙烧试验研究%Experimental Study on Fluidized Bed Roasting of Copper-cobalt Sulfide Concentrate from Congo DRC

    Institute of Scientific and Technical Information of China (English)

    李鑫; 周韫; 王含渊

    2015-01-01

    针对刚果(金)某铜钴矿选矿所得硫化铜钴精矿进行了沸腾焙烧试验研究。研究表明,在焙烧温度620℃、空气线速度0�43 m/s、风矿比3.33 m3/kg的条件下,硫化铜钴精矿焙烧效果较好。焙砂和焙烧烟尘酸浸试验结果进一步验证了最佳焙烧条件,焙砂铜、钴、铁浸出率分别为96.43%,87.06%和10.89%,焙烧烟尘铜、钴、铁浸出率分别为96.32%,84.02%和17.12%。试验研究结果为该类型铜钴矿选冶联合工艺选择及后期工业化应用提供了实验数据与技术支持。%An experimental study was carried out on the fluidized bed roasting of copper⁃cobalt sulfide concentrate obtained after processing of copper⁃cobalt ores from Congo DRC. It is suggested that a better effect be obtained for the roasting of copper⁃cobalt concentrate at a temperature of 620℃, with linear velocity of air at 0.43 m/s, air/ore ratio of 3.33 m3/kg. The further acid leaching test of calcine and roasting dust testified the optimum roasting condition. The leaching rates of Cu, Co, Fe reached 96. 43%, 87. 06%, 10. 89%, respectively, from the calcine, and 96. 32%, 84�02%, 17.12%, respectively, from the roasting dust. The experiment result can provide some sort of experimental reference and technical support for the selection of a combined process of concentrating and metallurgy, as well as the following industrialization of fluidized bed roasting technique for such copper⁃cobalt sulfide concentrate in future.

  1. Copper hypersensitivity.

    Science.gov (United States)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-10-01

    The world production of copper is steadily increasing. Although humans are widely exposed to copper-containing items on the skin and mucosa, allergic reactions to copper are only infrequently reported. To review the chemistry, biology and accessible data to clarify the implications of copper hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common. As a metal, it possesses many of the same qualities as nickel, which is a known strong sensitizer. Cumulative data on subjects with presumed related symptoms and/or suspected exposure showed that a weighted average of 3.8% had a positive patch test reaction to copper. We conclude that copper is a very weak sensitizer as compared with other metal compounds. However, in a few and selected cases, copper can result in clinically relevant allergic reactions.

  2. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part I. the absorption of hydrogen sulfide in metal sulfate solutions

    NARCIS (Netherlands)

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    The desulfurization of gas streams using aqueous iron(II)sulfate (Fe(II)SO4), zinc sulfate (ZnSO4) and copper sulfate (CuSO4) solutions as washing liquor is studied theoretically and experimentally. The desulfurization is accomplished by a precipitation reaction that occurs when sulfide ions and met

  3. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part I. the absorption of hydrogen sulfide in metal sulfate solutions

    NARCIS (Netherlands)

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    The desulfurization of gas streams using aqueous iron(II)sulfate (Fe(II)SO4), zinc sulfate (ZnSO4) and copper sulfate (CuSO4) solutions as washing liquor is studied theoretically and experimentally. The desulfurization is accomplished by a precipitation reaction that occurs when sulfide ions and

  4. Copper transport.

    Science.gov (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  5. Alloyed copper chalcogenide nanoplatelets via partial cation exchange reactions.

    Science.gov (United States)

    Lesnyak, Vladimir; George, Chandramohan; Genovese, Alessandro; Prato, Mirko; Casu, Alberto; Ayyappan, S; Scarpellini, Alice; Manna, Liberato

    2014-08-26

    We report the synthesis of alloyed quaternary and quinary nanocrystals based on copper chalcogenides, namely, copper zinc selenide-sulfide (CZSeS), copper tin selenide-sulfide (CTSeS), and copper zinc tin selenide-sulfide (CZTSeS) nanoplatelets (NPLs) (∼20 nm wide) with tunable chemical composition. Our synthesis scheme consisted of two facile steps: i.e., the preparation of copper selenide-sulfide (Cu2-xSeyS1-y) platelet shaped nanocrystals via the colloidal route, followed by an in situ cation exchange reaction. During the latter step, the cation exchange proceeded through a partial replacement of copper ions by zinc or/and tin cations, yielding homogeneously alloyed nanocrystals with platelet shape. Overall, the chemical composition of the alloyed nanocrystals can easily be controlled by the amount of precursors that contain cations of interest (e.g., Zn, Sn) to be incorporated/alloyed. We have also optimized the reaction conditions that allow a complete preservation of the size, morphology, and crystal structure as that of the starting Cu2-xSeyS1-y NPLs. The alloyed NPLs were characterized by optical spectroscopy (UV-vis-NIR) and cyclic voltammetry (CV), which demonstrated tunability of their light absorption characteristics as well as their electrochemical band gaps.

  6. Copper hypersensitivity

    DEFF Research Database (Denmark)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-01-01

    hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  7. Sulfide detoxification in plant mitochondria.

    Science.gov (United States)

    Birke, Hannah; Hildebrandt, Tatjana M; Wirtz, Markus; Hell, Rüdiger

    2015-01-01

    In contrast to animals, which release the signal molecule sulfide in small amounts from cysteine and its derivates, phototrophic eukaryotes generate sulfide as an essential intermediate of the sulfur assimilation pathway. Additionally, iron-sulfur cluster turnover and cyanide detoxification might contribute to the release of sulfide in mitochondria. However, sulfide is a potent inhibitor of cytochrome c oxidase in mitochondria. Thus, efficient sulfide detoxification mechanisms are required in mitochondria to ensure adequate energy production and consequently survival of the plant cell. Two enzymes have been recently described to catalyze sulfide detoxification in mitochondria of Arabidopsis thaliana, O-acetylserine(thiol)lyase C (OAS-TL C), and the sulfur dioxygenase (SDO) ethylmalonic encephalopathy protein 1 (ETHE1). Biochemical characterization of sulfide producing and consuming enzymes in mitochondria of plants is fundamental to understand the regulatory network that enables mitochondrial sulfide homeostasis under nonstressed and stressed conditions. In this chapter, we provide established protocols to determine the activity of the sulfide releasing enzyme β-cyanoalanine synthase as well as sulfide-consuming enzymes OAS-TL and SDO. Additionally, we describe a reliable and efficient method to purify OAS-TL proteins from plant material.

  8. Influence of copper minerals on cyanide leaching of gold

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The paper thermodynamically examined the behavior of various copper minerals in cyanide solu-tions and investigated the influence of copper minerals on cyanide leaching of gold. In elucidating the influence of copper minerals on cyanide leaching of gold, copper minerals were classified into two types according to their solubility in cyanide solutions by proposing two concepts, cyaniding easily soluble copper (ECu) and cyaniding insoluble copper. The former involves copper occurrence in metal, oxides and secondary sulfides, and the latter refers mainly to primary sulfides. Experimental results show that not all the total copper in an ore affected cyanide leaching of gold, while cyaniding easily soluble copper turns out to be the decisive factor that interferes with gold cyanidation by causing decrease in gold cyanidation recovery and increase in cyanide consumption. When cyaniding easily soluble copper content (wE(Cu)) lies in the range of 0-0.25%, it linearly affects gold cyanidation recovery (R) as well as cyanide consumption (mc). The regression equations have been worked out to be R(%)=94.177 5-142.735 7 wE(Cu) with a correlation coefficient of -0.902 and mc=5.590 7+33.572 9 wE(Cu) with a correlation coefficient of 0.945, respectively.

  9. Comprehensive Recovery of Copper,Gold and Sulfide from Copper-Gold Concentrates Using Wet Method with Ultra-fine Grinding Technology%超细磨技术在铜金精矿湿法综合回收铜金硫中的应用研究

    Institute of Scientific and Technical Information of China (English)

    张文波; 董常平; 陈庆根; 李晓伟

    2013-01-01

    对于某矿山浮选产出的铜金精矿,由于铜的影响及黄铜矿和黄铁矿等物质对金的包裹作用的影响,直接氰化浸出的金、铜回收率均很低,虽然采用火法工艺处理该类精矿可较好地解决金、铜回收率低的问题,但是存在环境污染等问题。重点对铜金精矿超细磨-热压浸出-萃取-电积提取铜、浸出渣硫代硫酸钠法提取金和煤油溶解回收单质硫的综合回收工艺进行了研究,结果表明应用该综合回收工艺之后,铜、金和单质硫的回收率分别达到95%、98%和99%,具有有价金属综合回收率高且对环境污染小的优点。%As the impact of the copper and the chalcopyrite and pyrite inclusions of gold,the copper-gold concentrate which is the output of a mining flotation was cyanided directly,and the recoveries of gold and copper were very low.Although the problem can be solved by using pyrometallurgical processes dealing with the concentrates,but that cause environmental pollution and other issues.The copper-gold concentrate comprehensive recovery process was studied,which extracting copper from copper-gold concentrate using the process of ultra-fine grinding-hot leaching-extraction-electrowinning,extracting gold from leach residue using sodium thiosulfate method,recovering elemental sulfur using kerosene dissolved.The process has a lot of advantages,such as high recovery of valuable metals and environment friendly.The recovery rate of copper,gold and sulfur are up to 95%, 98%and 99%respectively.

  10. The susceptibility of 90Cu-10Ni alloy to stress corrosion cracking in seawater polluted by sulfide ions

    Science.gov (United States)

    Domiaty, A. El; Alhajji, J. N.

    1997-08-01

    Electrochemical polarization measurements and slow strain rate tests (SSRT) of a 90Cu-10Ni alloy in highly sulfide polluted seawater were conducted to investigate stress-corrosion cracking (SCC) behavior. The severity of the SCC depends on the sulfide concentration in the seawater. The severity increases as the concentration increases. Because the major time in SCC is spent in the initiation process of the propagating crack, the fracture toughness has only a minor effect in the component life failed by SCC. The SCC behavior of CDA706 is strictly linked to sulfide concentration in the range of 100 to 1000 ppm. The general corrosion of Cu-Ni alloys in low (100 ppm) sulfide polluted seawater increases due to the selective copper dissolution. Cyclic polarization measurements confirmed that the corrosion rate decreases slightly as the sulfide concentration increases. Pitting tendency was high in the low concentration range of sulfide and low in the high concentration range. The presence of stresses in SCC removes the protective layer as it increases during testing of the specimen or during the actual service of a component. The authors propose that film rupture occurred, and two proposed SCC mechanisms were operational, namely sulfide stress cracking associated with the anodic dissolution in the low sulfide concentration range and hydrogen embrittlement, which was dominant in the high sulfide concentration range. It was found that a synergism exists between sulfide and stress that enhances the effect of the latter.

  11. Sulfide oxidation in a biofilter

    DEFF Research Database (Denmark)

    Pedersen, Claus Lunde; Liu, Dezhao; Hansen, Michael Jørgen

    2012-01-01

    oxidizing bacteria but several fungal families including Trichocomaceae. A positive correlation was found between the presence of mold and sulfide uptake. However there have been no reports on fungi metabolizing hydrogen sulfide. We hypothesize that the mold increases the air exposed surface, enabling...... higher hydrogen sulfide uptake followed by oxidation catalyzed by iron-containing enzymes such as cytochrome c oxidase in a process uncoupled from energy conservation....

  12. Influences of Corrosive Sulfur on Copper Wires and Oil-Paper Insulation in Transformers

    Directory of Open Access Journals (Sweden)

    Jian Li

    2011-10-01

    Full Text Available Oil-impregnated paper is widely used in power transmission equipment as a reliable insulation. However, copper sulphide deposition on oil-paper insulation can lead to insulation failures in power transformers. This paper presents the influences of copper sulfur corrosion and copper sulphide deposition on copper wires and oil-paper insulation in power transformers. Thermal aging tests of paper-wrapped copper wires and bare copper wires in insulating oil were carried out at 130 °C and 150 °C in laboratory. The corrosive characteristics of paper-wrapped copper wires and bare copper wires were analyzed. Dielectric properties of insulation paper and insulating oil were also analyzed at different stages of the thermal aging tests using a broadband dielectric spectrometer. Experiments and analysis results show that copper sulfide deposition on surfaces of copper wires and insulation paper changes the surface structures of copper wires and insulation paper. Copper sulfur corrosion changes the dielectric properties of oil-paper insulation, and the copper sulfide deposition greatly reduces the electrical breakdown strength of oil-paper insulation. Metal passivator is capable of preventing copper wires from sulfur corrosion. The experimental results are helpful for investigations for fault diagnosis of internal insulation in power transformers.

  13. Characterization and recovery of copper values from discarded slag.

    Science.gov (United States)

    Das, Bisweswar; Mishra, Barada Kanta; Angadi, Shivakumar; Pradhan, Siddharth Kumar; Prakash, Sandur; Mohanty, Jayakrushna

    2010-06-01

    In any copper smelter large quantities of copper slag are discarded as waste material causing space and environmental problems. This discarded slag contains important amounts of metallic values such as copper and iron. The recovery of copper values from an Indian smelter slag that contains 1.53% Cu, 39.8% Fe and 34.65% SiO(2) was the focus of the present study. A complete investigation of the different phases present in the slag has been carried out by means of optical microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It is observed that iron and silica are mostly associated with the fayalite phase whereas copper is present in both oxide and sulfide phases. These oxide and sulfide phases of copper are mostly present within the slag phase and to some extent the slag is also embedded inside the oxide and sulfide phases. The recovery of copper values from the discarded slag has been explored by applying a flotation technique using conventional sodium isopropyl xanthate (SIX) as the collector. The effects of flotation parameters such as pH and collector concentration are investigated. Under optimum flotation conditions, it is possible to achieve 21% Cu with more than 80% recovery.

  14. 铜富氧底吹熔池熔炼过程机理及多相界面行为%Mechanism and multiphase interface behavior of copper sulfide concentrate smelting in oxygen-enriched bottom blowing furnace

    Institute of Scientific and Technical Information of China (English)

    郭学益; 王亲猛; 廖立乐; 田庆华; 张永柱

    2014-01-01

    通过深入分析铜富氧底吹熔池熔炼过程,结合铜冶金过程相关理论,构建了底吹熔炼体系机理模型。该模型在反应区沿纵向分为7个功能层,分别为烟气层、矿料分解过渡层、渣层、造渣过渡层、造锍过渡层、弱氧化层和强氧化层;炉内沿横向分为反应区、分离过渡区和液相澄清区3个功能区;各层/区分别承担不同的功能,构成一个有机整体,在熔体流场作用下,体系中多相多组元如CuFeS2、FeS2、Cu2S、FeS、2FeO·SiO2、Cu2O、FeO、Fe3O4、SO2、H2O、N2、S2等因物化性质差异,通过层/区间的界面进行快速传质行为;底吹熔炼体系处于动态的非稳态相平衡状态,氧势-硫势在炉内纵向及横向方向上均有梯度变化,通过合理控制不同层/区的氧势-硫势大小,可强化反应过程,进一步提升底吹炉熔炼能力。%Mechanism model of copper oxygen-enriched bottom blowing smelting (BBS) is constructed by analyzing smelting process deeply, combined with related theories of copper metallurgical process. Model ’s cross section includes seven functional layers, i.e. gas layer, mineral decomposition transition layer, slag layer, slag formation transition layer, matte formation transition layer, weak oxide layer and strong oxide layer. Longitudinal section is divided into three functional regions, including reaction region, separation transition region and liquid phase clarification region. The layers or regions play different roles and constitute an organic unit. Ploycomponent, such as CuFeS2,FeS2,Cu2S,FeS,2FeO·SiO2,Cu2O,FeO,Fe3O4,SO2,H2O,N2 and S2, transfers quickly through the interface between different layers and regions, with the effect of character differentiation and fluid flow. BBS is at the state of dynamic non-steady multiphase equilibrium, and the value of oxygen and sulfur potential changes gradually in longitudinal and cross direction, and the capacity of BBS can be

  15. Interfacial tension studies between Fe-Cu-Ni sulfide and halo-norilsk basalt slag system

    Institute of Scientific and Technical Information of China (English)

    SU Shangguo; Jim Mungall; WANG Jian; GENG Ke

    2005-01-01

    The interfacial tension of the matte/halo-Norilsk basalt slag systems of FeS-Cu2S-Ni3S2 and FeO-FeS were investigated using the sessile drop technique. The results indicate that interfacial tension decreases with increasing copper and nickel contents in the matte of FeS-Cu2S-Ni3S2 system while it increases with increasing oxygen content in the matte of FeO-FeS system. It is inferred from these results that two conditions are critical for the formation of giant Cu-Ni sulfide deposits. One is that mafic-ultramafic parent magma of sulfide deposits should be rich in copper and nickel where due to the low interfacial tension, it is difficult to form sulfide droplet in the early stage of magma evolution. In other words, sulfide liquid conglomeration occurs more difficultly. The other condition is that the magma emplacement should be shallow; and a lot of faults occur in the magma emplacement field. Since oxygen content is high in the environment, interfacial tension is high, which helps sulfide liquid conglomeration and consequently Cu-Ni sulfide deposits form.

  16. Development of novel copper-based sorbents for hot-gas cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.

    1991-01-01

    The objective of this investigation is to evaluate several novel copper-based binary oxides for their suitability as regenerable sorbents for hot gas cleanup application in the temperature range of 650{degree} to 850{degree}C (1200{degree}--1550{degree}F). To achieve this objective, several novel copper-based binary oxide sorbents will be prepared. Experimental tests will be conducted at ambient pressure to determine the stability, sulfidation capacity, regenerability, and sulfidation kinetics of the novel sorbents. Tests will also be conducted at high pressure for the determination of the sulfidation reactivity, regenerability, and durability of the sorbents. The attrition characteristics of the sorbents will also be determined.

  17. The effect of primary copper slag cooling rate on the copper valorization in the flotation process

    Directory of Open Access Journals (Sweden)

    Aleksandar Mihajlović

    2015-06-01

    Full Text Available Technological procedure of slow cooling slag from primary copper production is applied in the purpose of copper recovery in the level of 98.5% to blister. This technological procedure is divided into two phases, first slow cooling of slag on the air for 24 hours, and then accelerated cooling with water for 48 hours. Within the research following methods were used: calculation of nonstationary slag cooling, verification of the calculation using computer simulation of slag cooling in the software package COMSOL Multiphysics and experimental verification of simulation results. After testing of the experimentally gained samples of slowly cooled slag it was found that this technological procedure gives the best results in promoting growth or coagulation of dispersed particles of copper sulfide and copper in the slag, thereby increasing the utilization of the flotation process with a decrease of copper losses through very fine particles.

  18. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  19. Influence of flotation cell volume and solids mass on kinetics of sulfide ore flotation

    OpenAIRE

    Plawski Michal; Bakalarz Alicja

    2016-01-01

    The paper presents studies on the influence of flotation cell capacity and mass of solids in the suspension on the flotation kinetics of sulfide copper ore. A sample of copper ore that was collected from the Polkowice Mine of KGHM Polska Miedz S.A. in Poland was used in the experiments. It was determined that neither the volume of flotation cell nor the mass of solids had influence on the type of kinetics equation of flotation. Copper-bearing minerals floated according to the second-order equ...

  20. Copper metallurgy at the crossroads

    Directory of Open Access Journals (Sweden)

    Habashi F.

    2007-01-01

    Full Text Available Copper technology changed from the vertical to the horizontal furnace and from the roast reaction to converting towards the end of the last century. However, the horizontal furnace proved to be an inefficient and polluting reactor. As a result many attempts were made to replace it. In the past 50 years new successful melting processes were introduced on an industrial scale that were more energy efficient and less polluting. In addition, smelting and converting were conducted in a single reactor in which the concentrate was fed and the raw copper was produced. The standing problem in many countries, however, is marketing 3 tonnes of sulfuric acid per tonne of copper produced as well as emitting large amounts of excess SO2 in the atmosphere. Pressure hydrometallurgy offers the possibility of liberating the copper industry from SO2 problem. Heap leaching technology has become a gigantic operation. Combined with solvent extraction and electrowinning it contributes today to about 20% of copper production and is expected to grow. Pressure leaching offers the possibility of liberating the copper industry from SO2 problem. The technology is over hundred years old. It is applied for leaching a variety of ores and concentrates. Hydrothermal oxidation of sulfide concentrates has the enormous advantage of producing elemental sulfur, hence solving the SO2 and sulfuric acid problems found in smelters. Precipitation of metals such as nickel and cobalt under hydrothermal conditions has been used for over 50 years. It has the advantage of a compact plant but the disadvantage of producing ammonium sulfate as a co-product. In case of copper, however, precipitation takes place without the need of neutralizing the acid, which is a great advantage and could be an excellent substitute for electrowinning which is energy intensive and occupies extensive space. Recent advances in the engineering aspects of pressure equipment design open the door widely for increased

  1. On the existence of free and metal complexed sulfide in the Arabian Sea and its oxygen minimum zone

    Science.gov (United States)

    Theberge, Stephen M.; Luther, George W.; Farrenkopf, Anna M.

    Free hydrogen sulfide was not detected in the oxygen minimum zone (OMZ) of the Arabian Sea during legs D1 (September 1992) and D3 (October-November 1992) of the Netherlands Indian Ocean Programme (NIOP). However, sulfide complexed to metals was detected by cathodic stripping square wave voltammetry at 2 nM or less throughout the water column. A slight increase in sulfide was measured in the OMZ relative to the surface waters and may be related to sulfur release from organic matter during decomposition. Sulfide complexes are of two general types at low concentrations of metal and sulfide. First, metals such as Mn, Fe, Co and Ni form complexes with bisulfide ion (HS -) that are kinetically labile to dissociation and are reactive. Second, metals such as Cu and Zn form multinuclear complexes with sulfide (S 2-) that are kinetically inert to dissociation; thus, they are less reactive than free (bi)sulfide and the labile metal bisulfide complexes. Zinc and copper sulfide complexes are important in allowing hydrogen sulfide to persist in seawater which contains measurable oxygen.

  2. Fuel gas desulfurization at elevated temperatures with copper-based sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Hill, A.H.; Lau, F.S. [Inst. of Gas Technology, Des Plaines, IL (United States); Flytzani-Stephanopoulos, M. [Tufts Univ., Medford, MA (United States); Honea, F.I. [Illinois Clean Coal Inst., Carbondale, IL (United States)

    1995-12-31

    Zinc-based sorbents, the leading candidates for hot gas cleanup, have been shown to suffer from zinc volatilization at elevated temperatures, leading to sorbent deterioration, increasing sorbent replacement costs. Copper-based sorbents, because of the high melting point of the metal, do not suffer from this problem. However, bulk copper oxide is generally reduced to metallic copper in reducing fuel gas environments leading to thermodynamic limitations, resulting in insufficient level of desulfurization. The reduction stability and therefore the desulfurization performance of copper oxide sorbents can be significantly improved by combining copper oxide with other oxides in a supported form or as bulk mixed metal oxides. This paper addresses the results of a systematic study of several novel copper-based sorbents for hot gas cleanup application. The evaluation criteria included reduction stability, sulfidation reactivity and regenerability at elevated temperatures. The performance of the most promising sorbent in long duration cycle sulfidation-regeneration tests is also presented.

  3. Sulfide intrusion and detoxification in Zostera marina

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    2014-01-01

    nutrition in general. By a global review of sulfide intrusion, coupled with a series of field studies and in situ experiments we elucidate sulfide intrusion and different strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis...... indicating a possible role of sulfide in the sulfur nutrition beside the detoxification function. Our results suggest different adaptations of Z. marina to reduced sediments and sulfide intrusion ranging from bacterial and chemical reoxidation of sulfide to sulfate to incorporation of sulfide into organic...

  4. A novel method for improving cerussite sulfidization

    Institute of Scientific and Technical Information of China (English)

    Qi-cheng Feng; Shu-ming Wen; Wen-juan Zhao; Qin-bo Cao; Chao L

    2016-01-01

    Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sul-fide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.

  5. Prevention of sulfide oxidation in sulfide-rich waste rock

    Science.gov (United States)

    Nyström, Elsa; Alakangas, Lena

    2015-04-01

    The ability to reduce sulfide oxidation in waste rock after mine closure is a widely researched area, but to reduce and/or inhibit the oxidation during operation is less common. Sulfide-rich (ca 30 % sulfur) waste rock, partially oxidized, was leached during unsaturated laboratory condition. Trace elements such as As and Sb were relatively high in the waste rock while other sulfide-associated elements such as Cu, Pb and Zn were low compared to common sulfide-rich waste rock. Leaching of unsaturated waste rock lowered the pH, from around six down to two, resulting in continuously increasing element concentrations during the leaching period of 272 days. The concentrations of As (65 mg/L), Cu (6.9 mg/L), Sb (1.2 mg/L), Zn (149 mg/L) and S (43 g/L) were strongly elevated at the end of the leaching period. Different alkaline industrial residues such as slag, lime kiln dust and cement kiln dust were added as solid or as liquid to the waste rock in an attempt to inhibit sulfide oxidation through neo-formed phases on sulfide surfaces in order to decrease the mobility of metals and metalloids over longer time scale. This will result in a lower cost and efforts of measures after mine closure. Results from the experiments will be presented.

  6. New influence factor inducing difficulty in selective flotation separation of Cu-Zn mixed sulfide minerals

    Science.gov (United States)

    Deng, Jiu-shuai; Mao, Ying-bo; Wen, Shu-ming; Liu, Jian; Xian, Yong-jun; Feng, Qi-cheng

    2015-02-01

    Selective flotation separation of Cu-Zn mixed sulfides has been proven to be difficult. Thus far, researchers have found no satisfactory way to separate Cu-Zn mixed sulfides by selective flotation, mainly because of the complex surface and interface interaction mechanisms in the flotation solution. Undesired activation occurs between copper ions and the sphalerite surfaces. In addition to recycled water and mineral dissolution, ancient fluids in the minerals are observed to be a new source of metal ions. In this study, significant amounts of ancient fluids were found to exist in Cu-Zn sulfide and gangue minerals, mostly as gas-liquid fluid inclusions. The concentration of copper ions released from the ancient fluids reached 1.02 × 10-6 mol/L, whereas, in the cases of sphalerite and quartz, this concentration was 0.62 × 10-6 mol/L and 0.44 × 10-6 mol/L, respectively. As a result, the ancient fluid is a significant source of copper ions compared to mineral dissolution under the same experimental conditions, which promotes the unwanted activation of sphalerite. Therefore, the ancient fluid is considered to be a new factor that affects the selective flotation separation of Cu-Zn mixed sulfide ores.

  7. Hydrogen sulfide adsorption on MOFs and MOF/graphite oxide composites.

    Science.gov (United States)

    Petit, Camille; Mendoza, Barbara; Bandosz, Teresa J

    2010-12-03

    Composites of a copper-based metal-organic framework (MOF) and graphite oxide (GO) were tested for hydrogen sulfide removal at ambient conditions. In order to understand the mechanisms of adsorption, the initial and exhausted samples were analyzed by various techniques including X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analyses, and sorption of nitrogen. Compared to the parent materials, an enhancement in hydrogen sulfide adsorption was found. It was the result of physical adsorption of water and H(2)S in the pore space formed at the interface between the MOF units and the graphene layers where the dispersive forces are the strongest. Besides physisorption, reactive adsorption was found as the main mechanism of retention. H(2)S molecules bind to the copper centers of the MOF. They progressively react with the MOF units resulting in the formation of copper sulfide. This leads to the collapse of the MOF structure. Water enhances adsorption in the composites as it allows the dissolution of hydrogen sulfide.

  8. Partition coefficients for Ni, Cu, Pd, Pt, Rh, and Ir between monosulfide solid solution and sulfide liquid and the formation of compositionally zoned Ni-Cu sulfide bodies by fractional crystallization of sulfide liquid

    DEFF Research Database (Denmark)

    Barnes, S.J.; Makovicky, E.; Makovicky, M.

    1996-01-01

    Many nickel–copper sulfide orebodies contain Cu- and Fe-rich portions. The Fe-rich ore is generally richer in Os, Ir, Ru, and Rh and poorer in Pt, Pd, and Au than the Cu-rich ore. In komatiite-hosted ores Ni tends to be concentrated in the Cu-rich ore, whereas in tholeiitic ores it tends to be co...

  9. Hydrogen sulfide in signaling pathways.

    Science.gov (United States)

    Olas, Beata

    2015-01-15

    For a long time hydrogen sulfide (H₂S) was considered a toxic compound, but recently H₂S (at low concentrations) has been found to play an important function in physiological processes. Hydrogen sulfide, like other well-known compounds - nitric oxide (NO) and carbon monoxide (CO) is a gaseous intracellular signal transducer. It regulates the cell cycle, apoptosis and the oxidative stress. Moreover, its functions include neuromodulation, regulation of cardiovascular system and inflammation. In this review, I focus on the metabolism of hydrogen sulfide (including enzymatic pathways of H₂S synthesis from l- and d-cysteine) and its signaling pathways in the cardiovascular system and the nervous system. I also describe how hydrogen sulfide may be used as therapeutic agent, i.e. in the cardiovascular diseases.

  10. Assaying the catalytic potential of transition metal sulfides for abiotic carbon fixation

    Science.gov (United States)

    Cody, G. D.; Boctor, N. Z.; Brandes, J. A.; Filley, T. R.; Hazen, R. M.; Yoder, H. S.

    2004-05-01

    A suite of nickel, cobalt, iron, copper, and zinc containing sulfides are assayed for the promotion of a model carbon fixation reaction with relevance to local reducing environments of the early Earth. The assay tests the promotion of hydrocarboxylation (the Koch reaction) wherein a carboxylic acid is synthesized via carbonyl insertion at a metal-sulfide-bound alkyl group. The experimental conditions are chosen for optimal assay, i.e., high reactant concentrations and pressures (200 MPa) to enhance chemisorption, and high temperature (250°C) to enhance reaction kinetics. All of the metal sulfides studied, with the exception CuS, promote hydrocarboxylation. Two other significant reactions involve the catalytic reduction of CO to form a surface-bound methyl group, detected after nucleophilic attack by nonane thiol to form methyl nonyl sulfide, and the formation of dinonyl sulfide via a similar reaction. Estimation of the catalytic turnover frequencies for each of the metal sulfides with respect to each of the primary reactions reveals that NiS, Ni 3S 2, and CoS perform comparably to commonly employed industrial catalysts. A positive correlation between the yield of primary product to NiS and Ni 3S 2 surface areas provides strong evidence that the reactions are surface catalytic in these cases. The sulfides FeS and Fe (1-x)S are unique in that they exhibit evidence of extensive dissolution, thus, complicating interpretation regarding heterogeneous vs. homogeneous catalysis. With the exception of CuS, each of the metal sulfides promotes reactions that mimic key intermediate steps manifest in the mechanistic details of an important autotrophic enzyme, acetyl-CoA synthase. The relatively high temperatures chosen for assaying purposes, however, are incompatible with the accumulation of thioesters. The results of this study support the hypothesis that transition metal sulfides may have provided useful catalytic functionality for geochemical carbon fixation in a prebiotic

  11. New data on the Hyrkkoelae U-Cu mineralization: the behaviour of native copper in a natural environment

    Energy Technology Data Exchange (ETDEWEB)

    Marcos, N. [Helsinki Univ. of Technology, Espoo (Finland); Ahonen, L. [Geological Survey of Finland, Helsinki (Finland)

    1999-05-01

    The Hyrkkoelae Cu-U mineralisation (SW Finland) is studied as an analogue to the behaviour of copper canister in crystalline bedrock. Uranium-native copper and uranium-copper corrosion products interactions are also addressed in this study. The integration of uranium series disequilibrium (USD) studies gives an estimate of the time-scales of the corrosion processes. The mineral assemblages native copper-copper sulfide, copper sulfides - copper iron sulfides, and native copper-copper oxide (cuprite) occur in open fractures at several depth intervals within granite pegmatites (GP). The surfaces of these open fractures have accumulations of uranophane crystals and other unidentified uranyl compounds. The secondary uranium minerals are mainly distributed around copper sulfide grains. Microscopic intergrowths of copper sulfides and uranyl compounds also have been observed. The surface of the fracture where native copper and cuprite occur is covered with uranium-rich smectite. The very low {sup 234}U/{sup 238}U activity ratio (0.29 - 0.39) in the main uranium fraction in smectite indicates chemical stable conditions (e.g., oxidising) during at least a time period comparable to the half-life of the {sup 234}U isotope (T{sub 1/2} = 2.44 x 10{sup 5} a). Groundwater samples were collected from intervals where copper minerals occur within open fractures. The Eh and pH conditions were measured during long-term pumping (2-4 weeks per sample). Eh was measured both in situ and an the surface using three electrodes (Pt, Au, C). The actual groundwater conditions are oxidising and would not allow the sulfidization of native copper. Sulfidization may be considered as on old phenomenon, older than the precipitation of uranyl phases in the samples. The end of sulfidization may be earlier than the precipitation and/or remobilisation of U(VI) phases in a time span from about 2 x 10{sup 5} years (precipitation of uranophane) to 2.44 x 10{sup 5} (remobilisation of U from smectite). (orig.)

  12. Oxidation Potentials in Matte Smelting of Copper and Nickel

    Science.gov (United States)

    Matousek, Jan W.

    2014-09-01

    The oxidation potential, given as the base-ten logarithm of the oxygen partial pressure in bars and the temperature [log pO2/ T, °C], defines the state of oxidation of pyrometallurgical extraction and refining processes. This property varies from copper making, [-6/1150]; to lead/zinc smelting, [-10/1200]; to iron smelting, [-13/1600]. The current article extends the analysis to the smelting of copper and nickel/copper sulfide concentrates to produce mattes of the type Cu(Ni)FeS(O) and iron silicate slags, FeOxSiO2—with oxidation potentials of [-7.5/1250].

  13. Development of novel copper-based sorbents for hot-gas cleanup. Technical report, September 1--November 30, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.

    1991-12-31

    The objective of this investigation is to evaluate several novel copper-based binary oxides for their suitability as regenerable sorbents for hot gas cleanup application in the temperature range of 650{degree} to 850{degree}C (1200{degree}--1550{degree}F). To achieve this objective, several novel copper-based binary oxide sorbents will be prepared. Experimental tests will be conducted at ambient pressure to determine the stability, sulfidation capacity, regenerability, and sulfidation kinetics of the novel sorbents. Tests will also be conducted at high pressure for the determination of the sulfidation reactivity, regenerability, and durability of the sorbents. The attrition characteristics of the sorbents will also be determined.

  14. Sulfidation as a natural antidote to metallic nanoparticles is overestimated: CuO sulfidation yields CuS nanoparticles with increased toxicity in medaka (Oryzias latipes) embryos.

    Science.gov (United States)

    Li, Lingxiangyu; Hu, Ligang; Zhou, Qunfang; Huang, Chunhua; Wang, Yawei; Sun, Cheng; Jiang, Guibin

    2015-02-17

    Sulfidation is considered as a natural antidote to toxicity of metallic nanoparticles (NPs). The detoxification contribution from sulfidation, however, may vary depending on sulfidation mechanisms. Here we present the dissolution-precipitation instead of direct solid-state-shell mechanism to illustrate the process of CuO-NPs conversion to CuS-NPs in aqueous solutions. Accordingly, the CuS-NPs at environmentally relevant concentrations showed much stronger interference on Japanese medaka (Oryzias latipes) embryo hatching than CuO-NPs, which was probably due to elevated free copper ions released from CuS-NPs, leading to significant increase in oxidative stress and causing toxicity in embryos. The larval length was significantly reduced by CuS-NPs, however, no other obviously abnormal morphological features were identified in the hatched larvae. Co-introduction of a metal ion chelator [ethylene diamine tetraacetic acid (EDTA)] could abolish the hatching inhibition induced by CuS-NPs, indicating free copper ions released from CuS-NPs play an important role in hatching interference. This work documents for the first time that sulfidation as a natural antidote to metallic NPs is being overestimated, which has far reaching implications for risk assessment of metallic NPs in aquatic environment.

  15. Determining Prehistoric Mining Practices in Southeastern Europe Using Copper Isotopes

    Science.gov (United States)

    Powell, Wayne; Mathur, Ryan; Bankoff, H. Arthur; Bulatović, Aleksandar; Filipović, Vojislav

    2017-04-01

    Copper was first smelted from malachite at 5000 BCE in Serbia. There the Eneolithic (Copper Age) began with the production of small jewelry pieces and progressed to the casting of massive copper tools near its end, approximately 2000 years later. However, copper metallurgy in southeastern Europe ceased or significantly decreased in the later third millennium, several centuries before the Bronze Age began. Whether this metallurgical hiatus was the result a cultural shift or depletion of natural resources remains an ongoing subject of debate. It has been speculated that the marked reduction in metal production at the Eneolithic-Bronze Age transition was due to the exhaustion of surficial weathered oxide ores and the technical inability to smelt the underlying sulfide minerals. The behavior of copper isotopes in near-surface environments allows us to differentiate highly weathered oxide ores that occur at Earth's surface from non-weathered sulfide ores that occur at greater depth. The oxidation of copper generates fluids and associated minerals that are enriched in the 65Cu isotope. Thus, oxidative weathering of sulfide ores leads to the development of three stratified isotopic reservoirs for copper: 1) oxides above the water table that are enriched in 65Cu; 2) residual weathered sulfides minerals at the water table that are depleted in 65Cu; and 3) non-fractionated, non-weathered sulfide ore below the water table. And so, the transformative shift to sulfide-based metallurgy will be delineated by a significant decrease in δ65Cu in copper artifacts corresponding to the first use of 65Cu-depleted residual ore. The degree of variability of primary ore composition from numerable ore deposits would likely result in the overlap of copper isotope composition between populations of artifacts. Therefore, shifts in the mean copper isotope values and associated standard deviations would best reflect changes in ores use. A baseline value of -0.2‰ ±0.5 (1) was determined

  16. A heterostructure composed of conjugated polymer and copper sulfide nanoparticles.

    Science.gov (United States)

    Narizzano, Riccardo; Erokhin, Victor; Nicolini, Claudio

    2005-08-25

    A heterostructure formed by a conjugated polymer and semiconducting nanoparticles was produced. The conjugated polymer was synthesized by oxidative copolymerization of 3-thiopheneacetic acid and 3-hexylthiophene, thus obtaining an amphiphilic polythiophene that allows the formation of a stable polymer layer at the air-water interface. Different numbers of monolayers were deposited on solid substrates. CuS nanoparticles were grown directly in the polymeric matrix using the carboxylic groups as nucleation centers. The reactions were monitored by quartz crystal microbalance, Brewster angle, and fluorescence microscopy. The heterostructure showed increased conductivity as compared to the pristine polymer.

  17. The Sedimentation—reworking Genesis of Dongchuan—type Stratiform Copper Deposits

    Institute of Scientific and Technical Information of China (English)

    华仁民

    1990-01-01

    The Dongchuan-type copper deposits have long been studied and well reported because of their great economic significance.The present paper proposes a "sedimentation-reworking" origin for this type of deposits to challenge the current "sedimentation-metamorphism" model which has been widely asscpted since 1970s.According to the new idea,orebodies were not directly deposited in the Luoxue dolomite where they are hosted.Instead,copper was preliminarily concentrated in the Yinmin Formation.During or after diagenesis,copper in the Yinmin Formation was mobilized and leached by hydrothermal solutions derived from the interstitial water of sediments under the high geothermal gradient of rift environment,Thus,copper was transported from the source bed(the Yinmin Formation)upward to the Luoxue algal dolomite where sulfur was produced by the reduction of sulfates.The copper sulfides were formed through replacement of initial sulfides by Cu-bearing solutions.

  18. Sulfide Capacity in Ladle Slag at Steelmaking Temperatures

    Science.gov (United States)

    Allertz, Carl; Sichen, Du

    2015-12-01

    Sulfide capacity measurements were conducted at 1823 K and 1873 K (1550 °C and 1600 °C) for the quaternary Al2O3-CaO-MgO-SiO2 system, for typical compositions used in the ladle in steelmaking. A copper-slag equilibrium was used under controlled oxygen and sulfur potentials. The sulfide capacity is strongly dependent on the composition and it was found to increase with the basic oxides, while it decreases with increase of the acidic components. It was found that CaO is more effective in holding sulfur in the slag compared to MgO when replacing SiO2. For the present slag compositions, Al2O3 and SiO2 behaved similar with respect to sulfur, and no considerable effect could be recorded when replacing one for the other. The sulfide capacity was also found to be strongly dependent on the temperature, increasing with temperature. The present results were compared with industrial data from the ladle, after vacuum treatment, and they were in good agreement.

  19. Material characterization of ancient Indian copper

    Indian Academy of Sciences (India)

    A Srivastava; R Balasubramaniam

    2003-10-01

    A chalcolithic (2350–1800 BC) copper chisel from Balathal has been characterized by X-ray diffraction, microstructural and electrochemical methods. The surface patina was composed of sulfates and oxysulfates in the outer layers while the inner layers were rich in copper oxides. The chisel exhibited smaller grain sizes near two of the surfaces while the structure in the interior was equiaxed. The deformed grains and inclusions near the surfaces and variation in the microhardness of the sample from different faces proved that the copper chisel was processed by cold deformation after initial casting of the square cross-section chisel. The electrochemical behaviour of chalcolithic Cu has been compared with that of a modern Cu sample by potentiodynamic polarization studies. The corrosion rate of chalcolithic Cu in aerated 3.5% NaCl solution was only marginally higher than that of modern Cu. The higher rate of corrosion has been attributed to the presence of second phase sulfide inclusions. The excellent condition of preservation of the 3800-year-old copper object, with no indications of stress corrosion cracking, suggests that pure copper or copper-based materials can be seriously considered as candidate canister materials for long-term underground storage of nuclear wastes in underground repositories.

  20. Synthesis and shape-tailoring of copper sulfide/indium sulfide-based nanocrystals.

    Science.gov (United States)

    Han, Wei; Yi, Luoxin; Zhao, Nan; Tang, Aiwei; Gao, Mingyuan; Tang, Zhiyong

    2008-10-01

    Heterostructured Cu2S-In2S3 nanocrystals with various shapes and compositions were synthesized by a high-temperature precursor-injection method using the semiconductor nanocrystal Cu1.94S as a catalyst. The intrinsic cationic deficiencies formed at high temperature by Cu ions made the Cu1.94S nanocrystal a good candidate for catalyzing the nucleation and subsequent growth of In 2S3 nanocrystals, eventually leading to the formation of heterostructured Cu2S-In2S3 nanocrystals. Gelification of the reaction systems, which were composed of different types of nanocrystal precursors and solvent, was found to be a very effective measure for controlling the growth kinetics of the heterostructured particles. Consequently, matchsticklike Cu2S3-In2S3 heterostructured nanorods, teardroplike quasi-core/shell Cu2S@In2S3 nanocrystals, and pencil-like In2S3 nanorods were successfully obtained by manipulating the gelification of the reaction system; this formed a solid experimental basis for further discussion of the growth mechanisms for differently shaped and structured nanocrystals. By reaction with 1,10-phenanthroline, a reagent that strongly and selectively binds to Cu(+), a compositional transformation from binary matchsticklike Cu2S-In2S3 nanorods to pure In2S3 nanorods was successfully achieved.

  1. Photoactive nanocrystals by low-temperature welding of copper sulfide nanoparticles and indium sulfide nanosheets.

    Science.gov (United States)

    Lim, Hui Min; Tan, Jia Yi; Batabyal, Sudip K; Magdassi, Shlomo; Mhaisalkar, Subodh G; Wong, Lydia H

    2014-12-01

    We successfully utilize the concept of coalescence and room-temperature sintering to prepare morphologically different nanoparticles. n-Type chalcogenide (CuIn5 S8 ) nanocrystals are synthesized at room temperature by simple mixing of oppositely charged precursor nanoparticles. The coalescence of polycation-coated CuS nanoparticles and negatively charged In2 S3 nanoplates is driven by close contact of the particles due to electrostatic interactions. Analysis by X-ray diffraction, transmission electron microscopy (TEM) imaging, and Raman spectroscopy confirms the formation of single-phase CuIn5 S8 without traceable secondary phase. In a photovoltaic device, the use of the coalesced particles yields a power conversion efficiency of 1.8%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Mechanism of Mineral Phase Reconstruction for Improving the Beneficiation of Copper and Iron from Copper Slag

    Science.gov (United States)

    Guo, Zhengqi; Zhu, Deqing; Pan, Jan; Zhang, Feng

    2016-09-01

    To maximize the recovery of iron and copper from copper slag, the modification process by adding a compound additive (a mixture of hematite, pyrite and manganous oxide) and optimizing the cooling of the slag was studied. The phase reconstruction mechanism of the slag modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that the synergy between the burnt lime and the compound additive promotes the generation of target minerals, such as magnetite and copper matte. In addition, the multifunctional compound additive is able to improve the fluidity of the molten slag, which facilitates the coalescence and growth of fine particles of the target minerals. As a result, the percentage of iron distributed in the form of magnetite increased from 32.9% to 65.1%, and that of the copper exiting in the form of metallic copper and copper sulfide simultaneously increased from 80.0% to 90.3%. Meanwhile, the grains of the target minerals in the modified slag grew markedly to a mean size of over 50 μm after slow cooling. Ultimately, the beneficiation efficiency of copper and iron was improved because of the ease with which the target minerals could be liberated.

  3. The Effect of Oxygen Potential on the Sulfide Capacity for Slags Containing Multivalent Species

    Science.gov (United States)

    Allertz, Carl; Selleby, Malin; Sichen, Du

    2016-10-01

    The dependence of sulfide capacity on the oxygen partial pressure for slags containing multivalent species was investigated experimentally using a slag containing vanadium oxide. Copper-slag equilibration experiments were carried out at 1873 K (1600 °C) in the approximate oxygen partial pressure range 10-15.4 to 10-9 atm. The sulfide capacity was found to be strongly dependent on the oxygen potential in this slag system, increasing with the oxygen partial pressure. The sulfide capacity changed by more than two orders of magnitude over the oxygen partial pressure range. The effect of changing oxygen partial pressure was found to be much greater than the effect of changing slag composition at a fixed oxygen partial pressure.

  4. Synthesis of furan from allenic sulfide derivatives

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, we report the synthesis of furan derivatives from allenic sulfides. By the reaction with NaH, β-Hydroxyl allenic sulfides were found to generate furan products in excellent yields with the removal of phenylthio group. β-Aldehyde allenic sulfides were found to give similar furan products with one more substituent when treated with additional nucleophilic reagents. β-ketone allenic sulfides can also cyclize to give furan derivatives with the promotion of P2O5.

  5. Synthesis of furan from allenic sulfide derivatives

    Institute of Scientific and Technical Information of China (English)

    PENG LingLing; ZHANG Xiu; MA Jie; ZHONG ZhenZhen; ZHANG Zhe; ZHANG Yan; WANG JianBo

    2009-01-01

    In this paper, we report the synthesis of furan derivatives from allenic sulfides. By the reaction with NaH.,β-Hydroxyl allenic sulfides were found to generate furan products in excellent yields with the removal of phenylthio group.β-Aldehyde allenic sulfides were found to give similar furan products with one more substituent when treated with additional nucleophilic reagents. β-ketone allenic sulfides can also cyclize to give furan derivatives with the promotion of P2O5.

  6. Determining the Optimum Cut-Off Grades in Sulfide Copper Deposits / Określanie Optymalnej Wartości Odcięcia Zawartości Procentowej Pierwiastka Użytecznego W Złożach Siarczku Miedzi

    Science.gov (United States)

    Rahimi, Esmaeil; Oraee, Kazem; Shafahi, Zia Aldin; Ghasemzadeh, Hasan

    2015-03-01

    Optimum cut-off grades determination in mining life affects production planning and ultimate pit limit and it is also important from social, economical and environmental aspects. Calculation of optimum cut-off grades has been less considered for mines containing various mineral processing methods. In this paper, an optimization technique is applied to obtain optimum cut-off grades for both concentration and heap leaching processes. In this technique, production costs and different recoveries of heap leaching method directed into modeling different annual cash flows in copper mines. Considering the governing constraints, the Lagrange multiplier method is practiced to optimize the cut-off grades in which the objective function is supposed to maximize Net Present Value. The results indicate the effect of heap leaching process on the optimum cut-off grades of primary and secondary sulfide deposits. Określanie optymalnego poziomu odcięcia dla zawartości procentowej pierwiastka użytecznego ma poważny wpływ na planowanie produkcji, określanie ostatecznych limitów zasobów złoża; jest to także ważna kwestia z punktu widzenia kwestii społecznych, ekonomicznych i środowiskowych. Obliczanie optymalnego poziomu odcięcia dla zawartości procentowej pierwiastka użytecznego nie było zwykle szeroko rozważane w przypadku kopalni prowadzących ciągły system przeróbki. W pracy tej przedstawiono technikę optymalizacji określania poziomu zawartości procentowej pierwiastka użytecznego z uwzględnieniem zarówno procesów koncentracji jak i ługowania. W metodzie uwzględniono koszty produkcji i różne wskaźniki odzysku rudy, wielkości te wykorzystane zostały do modelowania rocznych przepływów gotówki w kopalniach miedzi. Uwzględniając narzucone ograniczenia, zastosowano metodę mnożników Lagrange'a w celu optymalizacji określania poziomu zawartości procentowej pierwiastka użytecznego, gdzie przyjętą funkcją celu jest maksymalizacja wartości bie

  7. Sulfide anion interaction with Cu(100) and Cu modified Au(100): An electrochemical STM study

    Energy Technology Data Exchange (ETDEWEB)

    Schlaup, Christian; Spaenig, Alexander; Wandelt, Klaus [Institute of Physical and Theoretical Chemistry, University of Bonn (Germany); Broekmann, Peter [Department of Chemistry and Biochemistry, University of Berne Berne (Switzerland)

    2010-02-15

    We describe the formation of thin copper sulfide semiconductor films under electrochemical conditions. In a first step we investigated the fundamental interaction of the Cu(100) surface with a sulfide anions containing electrolyte. Beside the classical p(2 x 2)-S and c(2 x 6)-S adlayer phases we found the formation of a closer packed ''pseudo-c(2 x 2)''-S phase accompanied by an expansion of the topmost copper layer. For a further investigation of this ''pseudo-c(2 x 2)''-S phase, we switched from the bulk Cu(100) electrode to a copper monolayer on a Au(100) electrode, which can be easily prepared using copper underpotential deposition. Since such a copper monolayer is pseudomorphic to the Au(100) surface and therefore expanded by 12.5% with respect to the bulk Cu(100)-plane, exclusively a commensurate c(2 x 2)-S structure is instantaneously formed and remains stable over a wide potential range. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  8. 30 CFR 250.604 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250.604... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  9. 30 CFR 250.504 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250.504... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  10. 30 CFR 250.808 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250.808... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of...

  11. Influence of arsenic on iron sulfide transformations

    NARCIS (Netherlands)

    Wolthers, M.; Butler, I.B.; Rickard, D.

    2007-01-01

    The association of arsenate, As(V), and arsenite, As(III), with disordered mackinawite, FeS, was studied in sulfide-limited (Fe:S = 1:1) and excess-sulfide (Fe:S = 1:2) batch experiments. In the absence of arsenic, the sulfide-limited experiments produce disordered mackinawite while the

  12. Carbon-dot-based fluorescent turn-on sensor for selectively detecting sulfide anions in totally aqueous media and imaging inside live cells

    Science.gov (United States)

    Hou, Xianfeng; Zeng, Fang; Du, Fangkai; Wu, Shuizhu

    2013-08-01

    Sulfide anions are generated not only as a byproduct from industrial processes but also in biosystems. Hence, robust fluorescent sensors for detecting sulfide anions which are fast-responding, water soluble and biocompatible are highly desirable. Herein, we report a carbon-dot-based fluorescent sensor, which features excellent water solubility, low cytotoxicity and a short response time. This sensor is based on the ligand/Cu(II) approach so as to achieve fast sensing of sulfide anions. The carbon dot (CD) serves as the fluorophore as well as the anchoring site for the ligands which bind with copper ions. For this CD-based system, as copper ions bind with the ligands which reside on the surface of the CD, the paramagnetic copper ions efficiently quench the fluorescence of the CD, affording the system a turn-off sensor for copper ions. More importantly, the subsequently added sulfide anions can extract Cu2+ from the system and form very stable CuS with Cu2+, resulting in fluorescence enhancement and affording the system a turn-on sensor for sulfide anions. This fast-responding and selective sensor can operate in totally aqueous solution or in physiological milieu with a low detection limit of 0.78 μM. It displays good biocompatibility, and excellent cell membrane permeability, and can be used to monitor S2- levels in running water and living cells.

  13. Production of sulfur gases and carbon dioxide by synthetic weathering of crushed drill cores from the Santa Cruz porphyry copper deposit near Casa Grande, Pinal County, Arizona

    Science.gov (United States)

    Hinkle, M.E.; Ryder, J.L.; Sutley, S.J.; Botinelly, T.

    1990-01-01

    Samples of ground drill cores from the southern part of the Santa Cruz porphyry copper deposit, Casa Grande, Arizona, were oxidized in simulated weathering experiments. The samples were also separated into various mineral fractions and analyzed for contents of metals and sulfide minerals. The principal sulfide mineral present was pyrite. Gases produced in the weathering experiments were measured by gas chromatography. Carbon dioxide, oxygen, carbonyl sulfide, sulfur dioxide and carbon disulfide were found in the gases; no hydrogen sulfide, organic sulfides, or mercaptans were detected. Oxygen concentration was very important for production of the volatiles measured; in general, oxygen concentration was more important to gas production than were metallic element content, sulfide mineral content, or mineral fraction (oxide or sulfide) of the sample. The various volatile species also appeared to be interactive; some of the volatiles measured may have been formed through gas reactions. ?? 1990.

  14. STUDY OF HYDROGEN SULFIDE REMOVAL FROM GROUNDWATER

    Directory of Open Access Journals (Sweden)

    T. Lupascu

    2013-06-01

    Full Text Available The process of the hydrogen sulfide removal from the underground water of the Hancesti town has been investigated. By oxygen bubbling through the water containing hydrogen sulfide, from the Hancesti well tube, sulfur is deposited in the porous structure of studied catalysts, which decreases their catalytic activity. Concomitantly, the process of adsorption / oxidation of hydrogen sulfide to sulfate take place. The kinetic research of the hydrogen sulfide removal from the Hancesti underground water, after its treatment by hydrogen peroxide, proves greater efficiency than in the case of modified carbonic adsorbents. As a result of used treatment, hydrogen sulfide is completely oxidized to sulfates

  15. Effect of Na2CO3 Addition on Carbothermic Reduction of Copper Smelting Slag to Prepare Crude Fe-Cu Alloy

    Science.gov (United States)

    Guo, Zhengqi; Zhu, Deqing; Pan, Jian; Yao, Weijie; Xu, Wuqi; Chen, Jinan

    2017-09-01

    Copper smelting slag is a useful secondary resource containing high iron and copper, which can be utilized to prepare crude Fe-Cu alloy by a direct reduction-magnetic separation process for making weathering-resistant steel. However, it is difficult to recover iron and copper from the slag by direct reduction since the iron mainly occurs in fayalite and the copper is held in copper sulfide. Therefore, enhancement reduction of copper slag is conducted to improve the recovery of copper and iron. Additives such as Na2CO3 has been proven to be capable of reinforcing the reduction of refractory iron ore. In this research, the effect of Na2CO3 on the carbothermic reduction of copper slag was investigated, and phase transformations during reduction and the distributing characteristics of iron and copper in the alloy and non-metallic phases of the reduced pellets were also studied. The results show that the metallization rate of iron and copper was increased with the addition of Na2CO3, leading to higher iron and copper recovery in Fe-Cu alloy powder. X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) results confirm that Na2CO3 is capable of enhancing the reduction of fayaltie, copper silicate and copper sulfide, which agrees well with thermodynamic analysis. Furthermore, the reduction mechanism of copper slag was demonstrated based on systematic experimental observations.

  16. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, September 1--November 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Hill, A.H. [Institute of Gas Technology, Chicago, IL (United States); Flytzani-Stephanopoulos, M.; Li Li [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1994-03-01

    The objective of this investigation is to evaluate two novel copper-based sorbents, namely copper-chromium and copper-cerium, for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650{degree} to 850{degree}C. Such high temperatures will be required for the new generation of gas turbines (inlet >750{degree}C) in Integrated Gasification Combined Cycle (IGCC) systems. The effect of pre-reduction on the performance of the sorbents as well as the rate of different reactions occurring in cyclic sulfidation/regeneration, were studied in a thermogravimetric analyzer (TGA). Sulfidation was conducted with and without H{sub 2} and H{sub 2}O, and with and without pre-reduction in H{sub 2} or H{sub 2}/H{sub 2}O. The results of these tests indicate that reduction and regeneration of both sorbents occurs rapidly. Sulfidation of CuCr{sub 2}O{sub 4}, in H{sub 2}O-free and H{sub 2}-/H{sub 2}O-free gas indicates the possible sulfidation of both copper and chromium. Small quantities of SO{sub 2}, were released during sulfidation suggesting the possible oxidation of H{sub 2}S by the sorbent. Regeneration of the CuCr{sub 2}O{sub 4} was complete while regeneration of the CuO-CeO{sub 2} indicated possible limited sulfate formation.

  17. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, December 1, 1991--February 29, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Hill, A.H.; Wangerow, J.R. [Institute of Gas Technology, Chicago, IL (United States); Flytzani-Stephanopoulos, M.; Bo, L.; Patel, C. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1992-08-01

    The objective of this investigation is to evaluate several novel copper-based binary oxides for their suitability as regenerable sorbents for hot gas cleanup application in the temperature range of 650{degrees} to 850{degrees}C. To achieve this objective, several novel copper-based binary oxide sorbents will be prepared. Experimental tests will be conducted at ambient pressure to determine the stability, sulfidation capacity, regenerability, and sulfidation kinetics of the novel sorbents. Tests will also be conducted at high pressure for the determination of the sulfidation reactivity, regenerability, and durability of the sorbents. The attrition characteristics of the sorbents will also be determined.

  18. Multistage Carbonatization and Mineral Geochemistry of a Skarn—type Copper Deposit at Tongshan ,Guichi

    Institute of Scientific and Technical Information of China (English)

    邱瑞龙

    1991-01-01

    The Tongshan copper deposit at Guichi can be considered as a skarn-type copper deposit.Mul-ti-stage carbonatization was well developed in the skarn zone and copper-bearing orebodies,Mineralogy,mineral chemistry and stable isotope data allow it to be divided into five stages:(1)carbonatization of single calcite crystals in the skarn stage;(2)calcite carbonatization in the oxide stage;(3)carbonatization in the early sulfide stage;(4)carbonatization in the late sulfide stage;and (5)carbonatization in the post-sulfide stage.Carbonatization in the early sulide stage is ,among other things,closely related to copper mineralization and is one of the alteration indicators of copper mineralization of this type.C.O,Rb and Sr isotopic studies indicate that the cakites of skarn and oxide stages were formed from hydrothermal solutions predominated by magmatic water,and those of sulfide stage were formed from hydrothermal solutions mainly involving heated meteoric warer.The former was formed in the environment where ?o2(?o2>10-33and 10-33>?o2>10-36)(pH=7-8)is high as compared with the latter(10-35>?o2>10-38;pH=5.7).

  19. Coper Isotope Fractionation in Porphyry Copper Deposits: A Controlled Experiment

    Science.gov (United States)

    Ruiz, J.; Mathur, R.; Uhrie, J. L.; Hiskey, B.

    2001-12-01

    Previous studies have shown that copper is fractionated in the environment. However, the mechanisms for isotope fractionation and the role of organic and inorganic processes in the fractionation are not well understood. Here we used the well controlled experiments used by Phelps Dodge Corporation aimed at leaching copper from their ore deposits to constrain the mechanism of copper isotope fractionation in natural systems. The isotope data were collected on a Micromass Isoprobe. High temperature copper sulfides from ore deposits in Chile and Arizona yield delta 65Cu near 0 permil. The reproducibility of the data is better that 0.1 permil. Controlled experiments consisting of large columns of rocks were fed solutions containing bacteria such as Thiobacillus ferroxidans and Leptospirrilium ferroxidan. Solutions fom the columns were sampled for sixty days and analyzed for copper concentrations, oxidation potential, ferrous/ferric ratios and pH. The results indicate that the bacterially aided dissolution of copper fractionated copper. Preliminary experiments of copper dissolution not using bacteria show no isotope fractionation The original rock in the experiment has a delta 65Cu of -2.1. The first solutions that were collected from the columns had a delta 65Cu of -5.0 per mil. The liquid changed its isotopic composition from -50 to -10 during the sixty days of sampling. The greatest shift in the isotope ratios occurred the first 30 days when the copper recovered was less than 40% and the ferrous/ferric ratios were somewhat constant. At approximately 35 days after the start of the experiments, the copper recovery increases the ferrousferric ratio decreased and the copper isotope ratio of the fluids remained fairly constant. The data suggest that the bacteria are required to effectively fractionate copper isotopes in natural systems and that the mechanisms of bacterial aided copper dissolution may include a direct dissolution of the sulfides by the bacteria. Experiments

  20. Copper Recovery from Yulong Complex Copper Oxide Ore by Flotation and Magnetic Separation

    Science.gov (United States)

    Han, Junwei; Xiao, Jun; Qin, Wenqing; Chen, Daixiong; Liu, Wei

    2017-09-01

    A combined process of flotation and high-gradient magnetic separation was proposed to utilize Yulong complex copper oxide ore. The effects of particle size, activators, Na2S dosage, LA (a mixture of ammonium sulfate and ethylenediamine) dosage, activating time, collectors, COC (a combination collector of modified hydroxyl oxime acid and xanthate) dosage, and magnetic intensity on the copper recovery were investigated. The results showed that 74.08% Cu was recovered by flotation, while the average grade of the copper concentrates was 21.68%. Another 17.34% Cu was further recovered from the flotation tailing by magnetic separation at 0.8 T. The cumulative recovery of copper reached 91.42%. The modifier LA played a positive role in facilitating the sulfidation of copper oxide with Na2S, and the combined collector COC was better than other collectors for the copper flotation. This technology has been successfully applied to industrial production, and the results are consistent with the laboratory data.

  1. Improvement of copper-molybdenum ore beneficiation using a combined flotation and biohydrometallurgy method

    Institute of Scientific and Technical Information of China (English)

    Irina Pestryak; Valery Morozov; Jamsranjav Baatarhuu

    2013-01-01

    The authors present the results of analysis of material composition and experimental investigations of acid and biohydrometallurgical leaching of middlings on grain size,pH level,leaching process duration,temperature and slurry density.The rational parameters of flotation and acid-bacterial leaching of middlings providing an efficient release of valuable components from mineral complexes and recovery to flotation concentrate and leaching solution have been determined.A combined flowsheet and a beneficiation process for bulk flotation middlings of copper-molybdenum ore have been suggested,which include middlings grinding,sulfide minerals flotation,bacterial leaching of sulfide flotation tailings,liquid-phase extraction of dissolved copper and electrolysis of re-extraction eluates.The suggested combined method of cleaning of middlings of copper-molybdenum ores beneficiation provides the total copper recovery increase by 0.8% with a reduction of the cost price of saleable material by 0.5%.

  2. Influence of flotation cell volume and solids mass on kinetics of sulfide ore flotation

    Directory of Open Access Journals (Sweden)

    Plawski Michal

    2016-01-01

    Full Text Available The paper presents studies on the influence of flotation cell capacity and mass of solids in the suspension on the flotation kinetics of sulfide copper ore. A sample of copper ore that was collected from the Polkowice Mine of KGHM Polska Miedz S.A. in Poland was used in the experiments. It was determined that neither the volume of flotation cell nor the mass of solids had influence on the type of kinetics equation of flotation. Copper-bearing minerals floated according to the second-order equation, while the remaining components according to the first-order equation. The kinetic rate constants and maximum recovery of the studied components decreased with increasing solids mass in the flotation cell, regardless of the capacity of the cell. The best results were obtained for tests using a 1.0 dm3 cell, while the less favorable kinetics results were observed in the test with the smallest cell of 0.75 dm3 volume. The obtained results can be helpful in choosing the most appropriate methodology of upgrading the sulfide copper ore from Poland in order to obtain the best kinetics results.

  3. Synthesis, characterization, and reactivity of sulfided hexanuclear molybdenum cluster compounds

    Energy Technology Data Exchange (ETDEWEB)

    Spink, D.

    1990-09-21

    Hexanuclear molybdenum clusters with mixed chloride and sulfide bridging ligands were prepared by reacting {alpha}-MoCl{sub 2} with sodium hydrosulfide in the presence of sodium butoxide. The resulting species, Mo{sub 6}Cl{sub (8-x)}S{sub x}{center dot}npy(x {congruent} 3.6, n {congruent} 4, py = pyridine), was pyrophoric and insoluble. The mixed sulfide chloride cluster species Mo{sub 6}S{sub 4}Cl{sub 4}{center dot}6OPEt{sub 3} and Mo{sub 6}S{sub {approximately}5}Cl{sub {approximately}3}{center dot}6PEt{sub 3} and Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} were isolated and characterized. Phosphorus-31 nuclear magnetic resonance, electron paramagnetic resonance, and UV/visible spectra were obtained for each fraction. The completely sulfided cluster, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3}, was prepared similarly and used in various experiments as a possible precursor to Chevrel phase materials of the type Mo{sub 6}S{sub 8}or M{sub n}Mo{sub 6}S{sub 8}. With the goal of removing all of the triethylphosphine ligands, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} was reacted with the transition metal carbonyls molybdenum hexacarbonyl and dicobalt octacarbonyl. Reaction on the molecular sulfide cluster with copper(I) chloride in toluene gave a completely insoluble product. The reaction of Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} with propylene sulfide gave a product whose infrared spectra showed only very weak peaks associated with coordinated triethylphosphine. The elemental analysis of this product fit the formula Mo{sub 6}S{sub 8}{center dot}5SPEt{sub 3}. Reactivity of the outer ligands of the Mo{sub 6}S{sub 8}{center dot}npy and Mo{sub 6}S{sub 8}{center dot}(6{minus}x)PrNH{sub x} clusters were investigated. Crystalline Mo{sub 6}S{sub 8}{center dot}6THT was recovered from the reaction of the n-propylamine derivative with THT. A crystal structure determination was done. 87 refs., 12 fig., 15 tabs.

  4. Redox Biochemistry of Hydrogen Sulfide*

    OpenAIRE

    Kabil, Omer; Banerjee, Ruma

    2010-01-01

    H2S, the most recently discovered gasotransmitter, might in fact be the evolutionary matriarch of this family, being both ancient and highly reduced. Disruption of γ-cystathionase in mice leads to cardiovascular dysfunction and marked hypertension, suggesting a key role for this enzyme in H2S production in the vasculature. However, patients with inherited deficiency in γ-cystathionase apparently do not present vascular pathology. A mitochondrial pathway disposes sulfide and couples it to oxid...

  5. Hydrogen sulfide and translational medicine

    OpenAIRE

    Guo, Wei; Cheng, Ze-yu; Zhu, Yi-Zhun

    2013-01-01

    Hydrogen sulfide (H2S) along with carbon monoxide and nitric oxide is an important signaling molecule that has undergone large numbers of fundamental investigations. H2S is involved in various physiological activities associated with the regulation of homeostasis, vascular contractility, pro- and anti-inflammatory activities, as well as pro- and anti-apoptotic activities etc. However, the actions of H2S are influenced by its concentration, reaction time, and cell/disease types. Therefore, H2S...

  6. Elevated corrosion rates and hydrogen sulfide in homes with 'Chinese Drywall'

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Joseph G.; MacIntosh, David L. [Environmental Health and Engineering, Inc., 117 Fourth Avenue, Needham, MA (United States); Harvard School of Public Health, 677 Huntington Avenue, Boston, MA (United States); Saltzman, Lori E. [U.S. Consumer Product Safety Commission, Bethesda, MD (United States); Baker, Brian J. [Environmental Health and Engineering, Inc., 117 Fourth Avenue, Needham, MA (United States); Matheson, Joanna M.; Recht, Joel R. [U.S. Consumer Product Safety Commission, Bethesda, MD (United States); Minegishi, Taeko; Fragala, Matt A.; Myatt, Theodore A. [Environmental Health and Engineering, Inc., 117 Fourth Avenue, Needham, MA (United States); Spengler, John D.; Stewart, James H. [Environmental Health and Engineering, Inc., 117 Fourth Avenue, Needham, MA (United States); Harvard School of Public Health, 677 Huntington Avenue, Boston, MA (United States); McCarthy, John F., E-mail: jmcccarthy@eheinc.com [Environmental Health and Engineering, Inc., 117 Fourth Avenue, Needham, MA (United States)

    2012-06-01

    In December 2008, the U.S. Consumer Product Safety Commission (CPSC) began receiving reports about odors, corrosion, and health concerns related to drywall originating from China. In response, a detailed environmental health and engineering evaluation was conducted of 41 complaint and 10 non-complaint homes in the Southeast U.S. Each home investigation included characterization of: 1) drywall composition; 2) indoor and outdoor air quality; 3) temperature, moisture, and building ventilation; and 4) copper and silver corrosion rates. Complaint homes had significantly higher hydrogen sulfide concentrations (mean 0.82 vs. < LOD {mu}g/m{sup 3}, p < 0.05), and significantly greater rates of copper sulfide and silver sulfide corrosion compared to non-complaint homes (Cu{sub 2}S: 476 vs. < 32 A/30 d, p < 0.01; Ag{sub 2}S: 1472 vs. 389 A/30 d, p < 0.01). The abundance of carbonate and strontium in drywall was also elevated in complaint homes, and appears to be useful objective marker of problematic drywall in homes that meet other screening criteria (e.g., constructed or renovated in 2006-2007, reports of malodor and accelerated corrosion). This research provides empirical evidence of the direct association between homes constructed with 'Chinese Drywall' in 2006-2007 and elevated corrosion rates and hydrogen sulfide concentrations in indoor air. - Highlights: Black-Right-Pointing-Pointer Environmental measurements in homes with and without 'Chinese Drywall' Black-Right-Pointing-Pointer Homes with 'Chinese Drywall' had higher hydrogen sulfide concentrations Black-Right-Pointing-Pointer Homes with 'Chinese Drywall' had elevated corrosion rates Black-Right-Pointing-Pointer Study provides empirical evidence of reported associations.

  7. Formation and phase separation during the smelting of sulfide raw materials

    Science.gov (United States)

    Tarasov, A. V.; Paretsky, V. M.

    2009-10-01

    This paper discusses the most recent developments made at the Gintsvetmet Institute in technologies and equipment for single-stage autogenous smelting of copper sulfide raw materials to produce white metal and blister copper. In particular, the oxygen-flame smelting process and separation of highly basic calcium-containing slags are considered. This technology includes the oxygen-flame smelting process (KFP Process) to produce highly basic self-disintegrating ferrite-calcium slags with their subsequent flotation to recover copper. Also included is a sparging smelting process (FBP Process) to produce combined slags subjected to decopperizing inside the same furnace. Results of special investigations of the slag structure obtained in the KFP and FBP processes and substantiating selection of their chemical and phase composition are presented. These processes meet stringent requirements for advanced technologies with respect to energy conservation and environmental safety with different scales of production and within a wide range of specific conditions of particular operations.

  8. Settling of copper drops in molten slags

    Science.gov (United States)

    Warczok, A.; Utigard, T. A.

    1995-02-01

    The settling of suspended metal and sulfide droplets in liquid metallurgical, slags can be affected by electric fields. The migration of droplets due to electrocapillary motion phenomena may be used to enhance the recovery of suspended matte/metal droplets and thereby to increase the recovery of pay metals. An experimental technique was developed for the purpose of measuring the effect of electric fields on the settling rate of metallic drops in liquid slags. Copper drops suspended in CaO-SiO2-Al2O3-Cu2O slags were found to migrate toward the cathode. Electric fields can increase the settling rate of 5-mm-diameter copper drops 3 times or decrease the settling until levitation by reversal of the electric field. The enhanced settling due to electric fields decreases with increasing Cu2O contents in the slag.

  9. Sulfide intrusion and detoxification in seagrasses ecosystems

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis, tracing sulfur compounds combined with ecosystem parameters we found different spatial, intraspecific and interspecific strategies to cope with sulfidic sediments. 1......) Tolerance, by elimination (eg. Zostera marina); where we found precipitation of sulfide as non-toxic elemental sulfur on the inner wall of the root lacunae. 2) Utilization (eg. Z. marina), where seagrasses detoxify and incorporate sulfides by active uptake and metabolize to sulfate, representing a non...

  10. Cross-Comparison of Leaching Strains Isolated from Two Different Regions: Chambishi and Dexing Copper Mines

    Directory of Open Access Journals (Sweden)

    Baba Ngom

    2014-01-01

    Full Text Available A cross-comparison of six strains isolated from two different regions, Chambishi copper mine (Zambia, Africa and Dexing copper mine (China, Asia, was conducted to study the leaching efficiency of low grade copper ores. The strains belong to the three major species often encountered in bioleaching of copper sulfide ores under mesophilic conditions: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum. Prior to their study in bioleaching, the different strains were characterized and compared at physiological level. The results revealed that, except for copper tolerance, strains within species presented almost similar physiological traits with slight advantages of Chambishi strains. However, in terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the foreign microorganisms. In addition, microbial community analysis revealed that the different mixed cultures shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains.

  11. Cross-comparison of leaching strains isolated from two different regions: Chambishi and Dexing copper mines.

    Science.gov (United States)

    Ngom, Baba; Liang, Yili; Liu, Xueduan

    2014-01-01

    A cross-comparison of six strains isolated from two different regions, Chambishi copper mine (Zambia, Africa) and Dexing copper mine (China, Asia), was conducted to study the leaching efficiency of low grade copper ores. The strains belong to the three major species often encountered in bioleaching of copper sulfide ores under mesophilic conditions: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum. Prior to their study in bioleaching, the different strains were characterized and compared at physiological level. The results revealed that, except for copper tolerance, strains within species presented almost similar physiological traits with slight advantages of Chambishi strains. However, in terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the foreign microorganisms. In addition, microbial community analysis revealed that the different mixed cultures shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains.

  12. Copper allergy from dental copper amalgam?

    Science.gov (United States)

    Gerhardsson, Lars; Björkner, Bert; Karlsteen, Magnus; Schütz, Andrejs

    2002-05-06

    A 65-year-old female was investigated due to a gradually increasing greenish colour change of her plastic dental splint, which she used to prevent teeth grinding when sleeping. Furthermore, she had noted a greenish/bluish colour change on the back of her black gloves, which she used to wipe her tears away while walking outdoors. The investigation revealed that the patient had a contact allergy to copper, which is very rare. She had, however, had no occupational exposure to copper. The contact allergy may be caused by long-term exposure of the oral mucosa to copper from copper-rich amalgam fillings, which were frequently used in childhood dentistry up to the 1960s in Sweden. The deposition of a copper-containing coating on the dental splint may be caused by a raised copper intake from drinking water, increasing the copper excretion in saliva, in combination with release of copper due to electrochemical corrosion of dental amalgam. The greenish colour change of the surface of the splint is probably caused by deposition of a mixture of copper compounds, e.g. copper carbonates. Analysis by the X-ray diffraction technique indicates that the dominant component is copper oxide (Cu2O and CuO). The corresponding greenish/bluish discoloration observed on the back of the patient's gloves may be caused by increased copper excretion in tears.

  13. Measurement of labile copper in wine by medium exchange stripping potentiometry utilising screen printed carbon electrodes.

    Science.gov (United States)

    Clark, Andrew C; Kontoudakis, Nikolaos; Barril, Celia; Schmidtke, Leigh M; Scollary, Geoffrey R

    2016-07-01

    The presence of copper in wine is known to impact the reductive, oxidative and colloidal stability of wine, and techniques enabling measurement of different forms of copper in wine are of particular interest in understanding these spoilage processes. Electrochemical stripping techniques developed to date require significant pretreatment of wine, potentially disturbing the copper binding equilibria. A thin mercury film on a screen printed carbon electrode was utilised in a flow system for the direct analysis of labile copper in red and white wine by constant current stripping potentiometry with medium exchange. Under the optimised conditions, including an enrichment time of 500s and constant current of 1.0μA, the response range was linear from 0.015 to 0.200mg/L. The analysis of 52 red and white wines showed that this technique generally provided lower labile copper concentrations than reported for batch measurement by related techniques. Studies in a model system and in finished wines showed that the copper sulfide was not measured as labile copper, and that loss of hydrogen sulfide via volatilisation induced an increase in labile copper within the model wine system.

  14. Copper Products Capacity Expansion Stimulate the Copper Consumption

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>The dramatic growth of copper consumption in China can directly be seen from the expansion of copper products capacity.According to sta- tistics,in the past 4 years,the improvement on the balance of trade on copper bar,copper,and copper alloy and copper wire & cable has driven the growth of copper consumption a lot.

  15. Copper speciation in variably toxic sediments at the Ely Copper Mine, Vermont, United States

    Science.gov (United States)

    Kimball, Bryn E.; Foster, Andrea L.; Seal, Robert; Piatak, Nadine; Webb, Samuel M.; Hammarstrom, Jane M.

    2016-01-01

    At the Ely Copper Mine Superfund site, Cu concentrations exceed background values in both streamwater (160–1200 times) and sediments (15–79 times). Previously, these sediment samples were incubated with laboratory test organisms, and they exhibited variable toxicity for different stream sites. In this study we combined bulk- and microscale techniques to determine Cu speciation and distribution in these contaminated sediments on the basis of evidence from previous work that Cu was the most important stressor in this environment and that variable observed toxicity could have resulted from differences in Cu speciation. Copper speciation results were similar at microscopic and bulk scales. The major Cu species in the more toxic samples were sorbed or coprecipitated with secondary Mn (birnessite) and Fe minerals (jarosite and goethite), which together accounted for nearly 80% of the total Cu. The major Cu species in the less toxic samples were Cu sulfides (chalcopyrite and a covellite-like phase), making up about 80–95% of the total Cu, with minor amounts of Cu associated with jarosite or goethite. These Cu speciation results are consistent with the toxicity results, considering that Cu sorbed or coprecipitated with secondary phases at near-neutral pH is relatively less stable than Cu bound to sulfide at lower pH. The more toxic stream sediment sites were those that contained fewer detrital sulfides and were upstream of the major mine waste pile, suggesting that removal and consolidation of sulfide-bearing waste piles on site may not eliminate all sources of bioaccessible Cu.

  16. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    1999-01-01

    In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

  17. Alternative Anode Reaction for Copper Electrowinning

    Energy Technology Data Exchange (ETDEWEB)

    2005-07-01

    This report describes a project funded by the Department of Energy, with additional funding from Bechtel National, to develop a copper electrowinning process with lower costs and lower emissions than the current process. This new process also includes more energy efficient production by using catalytic-surfaced anodes and a different electrochemical couple in the electrolyte, providing an alternative oxidation reaction that requires up to 50% less energy than is currently required to electrowin the same quantity of copper. This alternative anode reaction, which oxidizes ferric ions to ferrous, with subsequent reduction back to ferric using sulfur dioxide, was demonstrated to be technically and operationally feasible. However, pure sulfur dioxide was determined to be prohibitively expensive and use of a sulfur burner, producing 12% SO{sub 2}, was deemed a viable alternative. This alternate, sulfur-burning process requires a sulfur burner, waste heat boiler, quench tower, and reaction towers. The electrolyte containing absorbed SO{sub 2} passes through activated carbon to regenerate the ferrous ion. Because this reaction produces sulfuric acid, excess acid removal by ion exchange is necessary and produces a low concentration acid suitable for leaching oxide copper minerals. If sulfide minerals are to be leached or the acid unneeded on site, hydrogen was demonstrated to be a potential reductant. Preliminary economics indicate that the process would only be viable if significant credits could be realized for electrical power produced by the sulfur burner and for acid if used for leaching of oxidized copper minerals on site.

  18. Phase analytical studies of industrial copper smelting slags. Part I: Silicate slags

    Science.gov (United States)

    Rüffler, R.; Dávalos, J.

    1998-12-01

    The pyrometallurgical extraction of copper from sulfide ore concentrates is determined by the behaviour of the associated iron during smelting. Hence, 57Fe Mössbauer spectroscopy is an attractive tool for studying the phases in silicate slags from German and Chilean smelting plants. Other methods used were ore microscopy, electron microprobe analysis, and X-ray powder diffraction.

  19. Copper(II) mediated facile and ultra fast peptide synthesis in methanol.

    Science.gov (United States)

    Mali, Sachitanand M; Jadhav, Sandip V; Gopi, Hosahudya N

    2012-07-18

    A novel, ultrafast, mild and scalable amide bond formation strategy in methanol using simple thioacids and amines is described. The mechanism suggests that the coupling reactions are initially mediated by CuSO(4)·5H(2)O and subsequently catalyzed by in situ generated copper sulfide. The pure peptides were isolated in satisfactory yields in less than 5 minutes.

  20. Hydrogen sulfide and vascular relaxation

    Institute of Scientific and Technical Information of China (English)

    SUN Yan; TANG Chao-shu; DU Jun-bao; JIN Hong-fang

    2011-01-01

    Objective To review the vasorelaxant effects of hydrogen sulfide (H2S) in arterial rings in the cardiovascular system under both physiological and pathophysiological conditions and the possible mechanisms involved.Data sources The data in this review were obtained from Medline and Pubmed sources from 1997 to 2011 using the search terms "hydrogen sulfide" and ""vascular relaxation".Study selection Articles describing the role of hydrogen sulfide in the regulation of vascular activity and its vasorelaxant effects were selected.Results H2S plays an important role in the regulation of cardiovascular tone.The vasomodulatory effects of H2S depend on factors including concentration,species and tissue type.The H2S donor,sodium hydrosulfide (NarS),causes vasorelaxation of rat isolated aortic rings in a dose-dependent manner.This effect was more pronounced than that observed in pulmonary arterial rings.The expression of KATP channel proteins and mRNA in the aortic rings was increased compared with pulmonary artery rings.H2S is involved in the pathogenesis of a variety of cardiovascular diseases.Downregulation of the endogenous H2S pathway is an important factor in the pathogenesis of cardiovascular diseases.The vasorelaxant effects of H2S have been shown to be mediated by activation of KATP channels in vascular smooth muscle cells and via the induction of acidification due to activation of the CI/HCO3 exchanger.It is speculated that the mechanisms underlying the vasoconstrictive function of H2S in the aortic rings involves decreased NO production and inhibition of cAMP accumulation.Conclusion H2S is an important endogenous gasotransmitter in the cardiovascular system and acts as a modulator of vascular tone in the homeostatic regulation of blood pressure.

  1. Copper and copper proteins in Parkinson's disease.

    Science.gov (United States)

    Montes, Sergio; Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

  2. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-10-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  3. Molybdenum sulfide/carbide catalysts

    Science.gov (United States)

    Alonso, Gabriel; Chianelli, Russell R.; Fuentes, Sergio; Torres, Brenda

    2007-05-29

    The present invention provides methods of synthesizing molybdenum disulfide (MoS.sub.2) and carbon-containing molybdenum disulfide (MoS.sub.2-xC.sub.x) catalysts that exhibit improved catalytic activity for hydrotreating reactions involving hydrodesulfurization, hydrodenitrogenation, and hydrogenation. The present invention also concerns the resulting catalysts. Furthermore, the invention concerns the promotion of these catalysts with Co, Ni, Fe, and/or Ru sulfides to create catalysts with greater activity, for hydrotreating reactions, than conventional catalysts such as cobalt molybdate on alumina support.

  4. Medical Functions of Hydrogen Sulfide.

    Science.gov (United States)

    Olas, Beata

    2016-01-01

    Hydrogen sulfide (H(2)S) is a gasomediator synthesized from L- and D-cysteine in various tissues. It is involved in a number of physiological and pathological processes. H(2)S exhibits antiatherosclerotic, vasodilator, and proangiogenic properties, and protects the kidney and heart from damage following ischemia/reperfusion injury. H(2)S donors may be natural or synthetic, and may be used for the safe treatment of a wide range of diseases. This review article summarizes the current state of knowledge of the therapeutic function of H(2)S.

  5. Ammonia and hydrogen sulfide removal using biochar

    Science.gov (United States)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  6. Micro and nano sulfide solid lubrication

    CERN Document Server

    Wang, Haidou; Liu, Jiajun

    2014-01-01

    Sulfide solid lubrication is a vital field of tribology with the potential to save both energy and materials. This book examines the low-temperature sulfuration technology developed in China, as well as two-step methods for preparing sulfide lubrication films.

  7. Hassle free synthesis of nanodimensional Ni, Cu and Zn sulfides for spectral sensing of Hg, Cd and Pb: A comparative study

    Science.gov (United States)

    Ansari, Zarina; Singha, Shib Shankar; Saha, Abhijit; Sen, Kamalika

    2017-04-01

    A simple room temperature synthesis method of Ni, Cu and Zn sulfide nanoparticles (NPs) in aqueous medium is reported here. The NPs stabilized in aqueous medium by the citrate ions were characterized by UV-vis, ζ potentials, TEM and Raman spectroscopic techniques. The solid NPs could be isolated from the aqueous medium when allowed to stand for a prolonged time ( 20 h). The solids were also characterized by IR and powder X-ray analysis. The nanoparticles were further used for the development of facile optical sensing and detection of heavy metal ions at trace scale. Alterations in the absorption spectra of the generated NPs were indicative of their interactions with heavy metal ions. Raman spectral measurements further validate the detection technique. It is found that out of the three synthesized nanoparticles, nickel sulfide NP is a specific sensor for mercury ions whereas zinc sulfide and copper sulfide NPs act as sensors for Hg2 +, Cd2 + and Pb2 +.

  8. Sulfide toxicity kinetics of a uasb reactor

    Directory of Open Access Journals (Sweden)

    D. R. Paula Jr.

    2009-12-01

    Full Text Available The effect of sulfide toxicity on kinetic parameters of anaerobic organic matter removal in a UASB (up-flow anaerobic sludge blanket reactor is presented. Two lab-scale UASB reactors (10.5 L were operated continuously during 12 months. The reactors were fed with synthetic wastes prepared daily using glucose, ammonium acetate, methanol and nutrient solution. One of the reactors also received increasing concentrations of sodium sulfide. For both reactors, the flow rate of 16 L.d-1 was held constant throughout the experiment, corresponding to a hydraulic retention time of 15.6 hours. The classic model for non-competitive sulfide inhibition was applied to the experimental data for determining the overall kinetic parameter of specific substrate utilization (q and the sulfide inhibition coefficient (Ki. The application of the kinetic parameters determined allows prediction of methanogenesis inhibition and thus the adoption of operating parameters to minimize sulfide toxicity in UASB reactors.

  9. Using XAS and SXRF to Study Copper in Wilson Disease at the Molecular and Tissue Level

    Science.gov (United States)

    Ralle, Martina; Blackburn, Ninian J.; Lutsenko, Svetlana

    2007-02-01

    Wilson disease (WD) is a genetic disorder of copper metabolism associated with severe hepatic, neurological, and psychiatric abnormalities. In WD, the billiary copper excretion is impaired and copper accumulates in tissues, particularly in the liver and the brain. The affected gene, ATP7B, encodes the copper transporting ATPase, Wilson disease protein (WNDP). WNDP has six copper binding sites in the N-terminal portion of the molecule. Each site includes the conserved amino acid sequence MXCXXC, and binds 1 Cu(I) through its 2 cysteine residues. We performed X-ray absorption studies at the Cu Kα-edge on the recombinant N-terminal domain of WNDP (N-WNDP). Copper was bound to N-WNDP either in vivo or in vitro in the presence of different reducing agents. We found that in N-WNDP copper is predominantly coordinated in a linear fashion by two cysteines, with the appearance of a Cu-Cu interaction when all metal binding sites are filled. Increasing amounts of reducing agents containing sulfide or phosphine groups led to binding of the exogenous ligands to copper thereby increasing the coordination number of copper from two to three. To better understand the role of copper in WD, we utilized livers of the 6-weeks-old Atp7b-/- mice (an animal model for WD) in which the copper concentration was 10-20-fold higher compared to that of the control mice. The distribution of copper in hepatocytes was evaluated by synchrotron based X-ray fluorescence microprobe (SXRF). We demonstrate that we can prepare liver slices that retain copper and can detect copper with subcellular resolution. On the same sections μ-XANES (spot size: 5 micron) was used to determine the oxidation state of copper.

  10. Integration of Semiconducting Sulfides for Full-Spectrum Solar Energy Absorption and Efficient Charge Separation.

    Science.gov (United States)

    Zhuang, Tao-Tao; Liu, Yan; Li, Yi; Zhao, Yuan; Wu, Liang; Jiang, Jun; Yu, Shu-Hong

    2016-05-23

    The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2-x S, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS-CdS-Cu2-x S heteronanorod for full-spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2-x S and CdS leads to staggered gaps, as confirmed by first-principles simulations. This band alignment causes effective electron-hole separation in the ternary system and hence enables efficient solar energy conversion.

  11. A computational study of adhesion between rubber and metal sulfides at rubber–brass interface

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Chian Ye; Hirvi, Janne T.; Suvanto, Mika; Bazhenov, Andrey S. [Department of Chemistry, University of Eastern Finland, P.O. Box 111, FI80101 Joensuu (Finland); Ajoviita, Tommi; Markkula, Katriina [R & D, Car Tyres, Nokian Tyres plc., P.O. Box 20, FI37101 Nokia (Finland); Pakkanen, Tapani A., E-mail: tapani.pakkanen@uef.fi [Department of Chemistry, University of Eastern Finland, P.O. Box 111, FI80101 Joensuu (Finland)

    2015-05-12

    Highlights: • An atomic level model for brass–rubber interactions has been presented. • The main adhesion force has been tracked to the rubber sulfur–brass zinc or brass copper interaction. • The model gives new understanding of the adhesion and can be used for further developments of the system. - Abstract: Computational study at level of density functional theory has been carried out in order to investigate the adhesion between rubber and brass plated steel cord, which has high importance in tire manufacturing. Adsorption of natural rubber based adsorbate models has been studied on zinc sulfide, ZnS(1 1 0), and copper sulfide, Cu{sub 2}S(1 1 1) and CuS(0 0 1), surfaces as the corresponding phases are formed in adhesive interlayer during rubber vulcanization. Saturated hydrocarbons exhibited weak interactions, whereas unsaturated hydrocarbons and sulfur-containing adsorbates interacted with the metal atoms of sulfide surfaces more strongly. Sulfur-containing adsorbates interacted with ZnS(1 1 0) surface stronger than unsaturated hydrocarbons, whereras both Cu{sub 2}S(1 1 1) and CuS(0 0 1) surfaces showed opposite adsorption preference as unsaturated hydrocarbons adsorbed stronger than sulfur-containing adsorbates. The different interaction strength order can play role in rubber–brass adhesion with different relative sulfide concentrations. Moreover, Cu{sub 2}S(1 1 1) surface exhibits higher adsorption energies than CuS(0 0 1) surface, possibly indicating dominant role of Cu{sub 2}S in the adhesion between rubber and brass.

  12. 21 CFR 177.2490 - Polyphenylene sulfide resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfide resins. 177.2490 Section 177... Components of Articles Intended for Repeated Use § 177.2490 Polyphenylene sulfide resins. Polyphenylene sulfide resins (poly(1,4-phenylene sulfide) resins) may be safely used as coatings or components...

  13. Analysis of copper losses throughout weak acid effluent flows generated during off-gas treatment in the New Copper Smelter RTB Bor

    Directory of Open Access Journals (Sweden)

    Dragana Ivšić-Bajčeta

    2013-09-01

    Full Text Available The previous inadequate treatment of off-gas in RTB Bor in Serbia has resulted in serious pollution of the environment and the possibly high losses of copper through the effluent flows. The project of New Copper Smelter RTB Bor, besides the new flash smelting furnace (FSF and the reconstruction of Pierce-Smith converter (PSC, includes more effective effluent treatment. Paper presents an analysis of the new FSF and PSC off-gas treatment, determination of copper losses throughout generated wastewaters and discussion of its possible valorization. Assumptions about the solubility of metals phases present in the FSF and PSC off-gas, obtained by the treatment process simulation, were compared with the leaching results of flue dusts. Determined wastewaters characteristics indicate that the PSC flow is significantly richer in copper, mostly present in insoluble metallic/sulfide form, while the FSF flow has low concentration of copper in the form of completely soluble oxide/sulfate. The possible scenario for the copper valorization, considering arsenic and lead as limiting factors, is the separation of the FSF and PSC flows, return of the metallic/sulfide solid phase to the smelting process and recovery from the sulfate/oxide liquid phase.

  14. Adequate hydrogen sulfide, healthy circulation

    Institute of Scientific and Technical Information of China (English)

    DU Jun-bao; CHEN Stella; JIN Hong-fang; TANG Chao-shu

    2011-01-01

    Previously,hydrogen sulfide (H2S) was considered to be a toxic gas.However,recently it was discovered that it could be produced in mammals and even in plants,throughtheproductionandmetabolismof sulfur-containing amino acids.In mammals,H2S is mainly catalyzed by cystathionine-γ-lyase (CSE),cystathionin-β-lyase (CBS) and 3-mercaptopyruvate sulfurtransferase (MPST) with the substrate of L-cysteine.Endogenous H2S exerts many important physiological and pathophysiological functions,including hypotensive action,vasorelaxation,myocardial dilation,inhibition of smooth muscle cell proliferation,and antioxidatve actions.Importantly,it plays a very important role in the pathogenesis of systemic hypertension,pulmonary hypertension,atherosclerosis,myocardialinjury,angiogenesis,hyperhomocysteinemi aandshock.Therefore,H2S is now being considered to be a novel gasotransmitter after nitric oxide and carbon monoxide in the regulation of circulatory system.

  15. Redox biochemistry of hydrogen sulfide.

    Science.gov (United States)

    Kabil, Omer; Banerjee, Ruma

    2010-07-16

    H(2)S, the most recently discovered gasotransmitter, might in fact be the evolutionary matriarch of this family, being both ancient and highly reduced. Disruption of gamma-cystathionase in mice leads to cardiovascular dysfunction and marked hypertension, suggesting a key role for this enzyme in H(2)S production in the vasculature. However, patients with inherited deficiency in gamma-cystathionase apparently do not present vascular pathology. A mitochondrial pathway disposes sulfide and couples it to oxidative phosphorylation while also exposing cytochrome c oxidase to this metabolic poison. This report focuses on the biochemistry of H(2)S biogenesis and clearance, on the molecular mechanisms of its action, and on its varied biological effects.

  16. Microbial control of hydrogen sulfide production

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J. [Univ. of Oklahoma, Tulsa, OK (United States)] [and others

    1995-12-31

    A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

  17. Structural studies in limestone sulfidation

    Energy Technology Data Exchange (ETDEWEB)

    Fenouil, Laurent A. [Univ. of California, Berkeley, CA (United States)

    1993-05-01

    This study investigates the sulfidation of limestone at high temperatures (700--900°C) as the first step in the design of a High-Temperature Coal-Gas Clean-Up system using millimeter-size limestone particles. Several workers have found that the rate of this reaction significantly decreases after an initial 10 to 15% conversion of CaCO3 to CaS. The present work attempts to explain this feature. It is first established that millimeter-size limestone particles do not sinter at temperatures up to the CaCO3 calcination point (899°C at 1.03 bar CO2} partial pressure). It is then shown that CaS sinters rapidly at 750 to 900°C if CO2 is present in the gas phase. Scanning Electron Microscope (SEM) photographs and Electron Dispersive Spectroscopy (EDS) data reveal that the CaS product layer sinters and forms a quasi-impermeable coating around the CaCO3 grains that greatly hinders more H2S from reaching the still unreacted parts of the stone. Moreover, most of the pores initially present within the limestone structure begin to disappear or, at least, are significantly reduced in size. From then on, subsequent conversion is limited by diffusion of H2S through the CaS layer, possibly by S2- ionic diffusion. The kinetics is then adequately described by a shrinking-core model, in which a sharp front of completely converted limestone is assumed to progress toward the center of the pellet. Finally, experimental evidence and computer simulations using simple sintering models suggest that the CaS sintering, responsible for the sharp decrease in the sulfidation rate, is surface-diffusion controlled.

  18. Cyanide and Copper Recovery from Barren Solution of the Merrill Crowe Process

    Science.gov (United States)

    Parga, José R.; Valenzuela, Jesús L.; Díaz, J. A.

    This paper is a brief overview of the role of inducing the nucleated precipitation of copper and cyanide in a flashtube serpentine reactor, using sodium sulfide as the precipitate and sulfuric acid as pH control. The results showed that pH had a great effect on copper cyanide removal efficiency and the optimum pH was about 3 to 3.5. At this pH value copper cyanide removal efficiency could be achieved above 97 and 99 %, when influent copper concentration ions were 650 and 900 ppm respectively. In this process the cyanide associated with the copper, zinc, iron cyanide complexes are released as HCN gas under strong acidic conditions, allowing it to be recycled back to the cyanidation process as free cyanide.

  19. Removal of methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide from contaminated air by Thiobacillus thioparus TK-m.

    OpenAIRE

    Kanagawa, T; Mikami, E.

    1989-01-01

    Methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide were efficiently removed from contaminated air by Thiobacillus thioparus TK-m and oxidized to sulfate stoichiometrically. More than 99.99% of dimethyl sulfide was removed when the load was less than 4.0 g of dimethyl sulfide per g (dry cell weight) per day.

  20. Hydrogen Sulfide Induces Oxidative Damage to RNA and DNA in a Sulfide-Tolerant Marine Invertebrate

    OpenAIRE

    Joyner-Matos, Joanna; Predmore, Benjamin L.; Stein, Jenny R.; Leeuwenburgh, Christiaan; Julian, David

    2010-01-01

    Hydrogen sulfide acts as an environmental toxin across a range of concentrations and as a cellular signaling molecule at very low concentrations. Despite its toxicity, many animals, including the mudflat polychaete Glycera dibranchiata, are periodically or continuously exposed to sulfide in their environment. We tested the hypothesis that a broad range of ecologically relevant sulfide concentrations induces oxidative stress and oxidative damage to RNA and DNA in G. dibranchiata. Coelomocytes ...

  1. Bioleaching of copper from old flotation tailings samples (Copper Mine Bor, Serbia

    Directory of Open Access Journals (Sweden)

    Stanković Srđan

    2015-01-01

    Full Text Available Bioleaching of samples taken from depths of 10, 15, and 20 meters from old flotation tailings of the Copper Mine Bor was conducted in shaken flasks using extremely acidic water of Lake Robuleas lixiviant. Yield of copper after five weeks of the bioleaching experiment was 68.34±1.21% for 15 m sample, 72.57±0.57% for 20 m sample and 97.78±5.50% for 10 m sample. The obtained results were compared to the results of acid leaching of the same samples and it was concluded that bioleaching was generally more efficient for the treatment of samples taken from depths of 10 m and 20 m. The content of pyrite in the 20 m sample, which contained the highest amount of this mineral, was reduced after bioleaching. Benefits of this approach are: recovery of substantial amounts of copper, reducing the environmental impact of flotation tailings and the application of abundant and free water from the Robule acidic lake as lixiviant. Results of the experiment showed that bioleaching can be more efficient than acid leaching for copper extraction from flotation tailings with higher sulfide contents. [Projekat Ministarstva nauke Republike Srbije, br. 176016 i br. 173048

  2. Nitrate-reducing, sulfide-oxidizing bacteria as microbial oxidants for rapid biological sulfide removal.

    Science.gov (United States)

    De Gusseme, Bart; De Schryver, Peter; De Cooman, Michaël; Verbeken, Kim; Boeckx, Pascal; Verstraete, Willy; Boon, Nico

    2009-01-01

    The emission of hydrogen sulfide into the atmosphere of sewer systems induces the biological production of sulfuric acid, causing severe concrete corrosion. As a possible preventive solution, a microbial consortium of nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) was enriched in a continuously stirred tank reactor in order to develop a biological technique for the removal of dissolved sulfide. The consortium, dominated by Arcobacter sp., was capable of removing 99% of sulfide. Stable isotope fractioning of the sulfide indicated that the oxidation was a biological process. The capacity of the NR-SOB consortium for rapid removal of sulfide was demonstrated by using it as an inoculum in synthetic and real sewage. Removal rates up to 52 mg sulfide-S g VSS(-1) h(-1) were achieved, to our knowledge the highest removal rate reported so far for freshwater species in the absence of molecular oxygen. Further long-term incubation experiments revealed the capacity of the bacteria to oxidize sulfide without the presence of nitrate, suggesting that an oxidized redox reserve is present in the culture.

  3. [Fatal outcome of an hydrogen sulfide poisoning].

    Science.gov (United States)

    Querellou, E; Jaffrelot, M; Savary, D; Savry, C; Perfus, J-P

    2005-10-01

    We report a case of fatal outcome poisoning by massive exposure to hydrogen sulfide of a sewer worker. This rare event was associated with a moderate intoxication of two members of the rescue team. The death was due to asystole and massive lung oedema. Autopsy analysis showed diffuse necrotic lesions in lungs. Hydrogen sulfide is a direct and systemic poison, produced by organic matter decomposition. The direct toxicity mechanism is still unclear. The systemic toxicity is due to an acute toxicity by oxygen depletion at cellular level. It is highly diffusable and potentially very dangerous. At low concentration, rotten egg smell must trigger hydrogen sulfide suspicion since at higher concentration it is undetectable, making intoxication possible. In case of acute intoxication, there is an almost instantaneous cardiovascular failure and a rapid death. Hydrogen sulfide exposure requires prevention measures and more specifically the use of respiratory equipment for members of the rescue team.

  4. Hydrogen sulfide in hemostasis: friend or foe?

    Science.gov (United States)

    Olas, Beata

    2014-06-25

    Hydrogen sulfide (H2S) is a well known toxic gas that is synthesized from the amino acids: cysteine (Cys) and homocysteine (Hcy) by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and mercaptopyruvate sulfurtransferase (3-MST). Hydrogen sulfide, like carbon monoxide (CO) or nitric oxide (NO) is a signaling molecule in different biological systems, including the cardiovascular system. Moreover, hydrogen sulfide plays a role in the pathogenesis of various cardiovascular diseases. It modulates different elements of hemostasis (activation of blood platelet, and coagulation process) as well as proliferation and apoptosis of vascular smooth muscle cells. However, the biological role and the therapeutic potential of H2S is not clear. This review summarizes the different functions of hydrogen sulfide in hemostasis.

  5. [Copper pathology (author's transl)].

    Science.gov (United States)

    Mallet, B; Romette, J; Di Costanzo, J D

    1982-01-30

    Copper is an essential dietary component, being the coenzyme of many enzymes with oxidase activity, e.g. ceruloplasmin, superoxide dismutase, monoamine oxidase, etc. The metabolism of copper is complex and imperfectly known. Active transport of copper through the intestinal epithelial cells involves metallothionein, a protein rich in sulfhydryl groups which also binds the copper in excess and probably prevents absorption in toxic amounts. In hepatocytes a metallothionein facilitates absorption by a similar mechanism and regulates copper distribution in the liver: incorporation in an apoceruloplasmin, storage and synthesis of copper-dependent enzymes. Metallothioneins and ceruloplasmin are essential to adequate copper homeostasis. Apart from genetic disorders, diseases involving copper usually result from hypercupraemia of varied origin. Wilson's disease and Menkes' disease, although clinically and pathogenetically different, are both marked by low ceruloplasmin and copper serum levels. The excessive liver retention of copper in Wilson's disease might be due to increased avidity of hepatic metallothioneins for copper and decreased biliary excretion through lysosomal dysfunction. Menkes' disease might be due to low avidity of intestinal and hepatic metallothioneins for copper. The basic biochemical defect responsible for these two hereditary conditions has not yet been fully elucidated.

  6. [Copper IUDs (author's transl)].

    Science.gov (United States)

    Thiery, M

    1983-10-01

    Following initial development of the Grafenberg ring in the 1920's, IUDs fell into disuse until the late 1950s, when plastic devices inserted using new technology began to gain worldwide acceptance. Further research indicated that copper had a significant antifertility effect which increased with increasing surface area, and several copper IUDs were developed and adapted, including the Copper T 200, the Copper T 220C, and the Copper T 380 A, probably the most effective yet. The Gravigard and Multiload are 2 other copper devices developed according to somewhat different principles. Copper devices are widely used not so much because of their great effectiveness as because of their suitability for nulliparous patients and their ease of insertion, which minimizes risk of uterine perforation. Records of 2584 women using Copper IUDs for 7190 women-years and 956 women using devices without copper for 6059 women-years suggest that the copper devices were associated with greater effectiveness and fewer removals for complications. Research suggests that the advantages of copper IUDs become more significant with increased duration of use. Contraindications to copper devices include allergy to copper and hepatolenticular degeneration. No carcinogenic or teratogenic effect of copper devices has been found, but further studies are needed to rule out other undesirable effects. Significant modifications of copper devices in recent years have been developed to increase their effectiveness, prolong their duration of usefulness, facilitate insertion and permit insertion during abortion or delivery. The upper limit of the surface area of copper associated with increased effectiveness appears to be between 200-300 sq mm, and at some point increases in copper exposure may provoke expulsion of the IUD. The duration of fertility inhibition of copper IUDs is usually estimated at 2-3 years, but recent research indicates that it may be 6-8 years, and some devices may retain copper surface

  7. Influences of silver sulfide on the bioleaching of chalcopyrite, pyrite and chalcopyrite-containing ore

    Institute of Scientific and Technical Information of China (English)

    胡岳华; 王军; 邱冠周; 王淀佐

    2002-01-01

    The effects of silver sulfide (Ag2S) on the bioleaching of chalcopyrite and pyrite were investigated in this paper. It has been shown that Ag2S enhanced the yields of bioleaching of chalcopyrite but inhibited the bio-oxidation of pyrite. The addition of Ag2S selectively increased the copper dissolution from the chalcopyrite-containing ores in shake flasks with a recovery of 85.3% compared with 24.3% without Ag2S, while slightly decreased the iron yields from 51% to 41.8%. The copper extraction of the chalcoopyrite-containing waste rock in column leaching charged with 18 kg mass increased up to 21.7% in the presence of Ag2S, while only 3.4% in the absence of the catalyst. The mechanism of Ag2S catalysis could be explained well by the "Mixed potential model".

  8. Air-water transfer of hydrogen sulfide

    DEFF Research Database (Denmark)

    Yongsiri, C.; Vollertsen, J.; Rasmussen, M. R.

    2004-01-01

    The emissions process of hydrogen sulfide was studied to quantify air–water transfer of hydrogen sulfide in sewer networks. Hydrogen sulfide transfer across the air–water interface was investigated at different turbulence levels (expressed in terms of the Froude number) and pH using batch...... experiments. By means of the overall mass–transfer coefficient (KLa), the transfer coefficient of hydrogen sulfide (KLaH2S), referring to total sulfide, was correlated to that of oxygen (KLaO2) (i.e., the reaeration coefficient). Results demonstrate that both turbulence and pH in the water phase play...... a significant role for KLaH2S. An exponential expression is a suitable representation for the relationship between KLaH2S and the Froude number at all pH values studied (4.5 to 8.0). Because of the dissociation of hydrogen sulfide, KLaH2S increased with decreasing pH at a constant turbulence level. Relative...

  9. Mechanism of mechanical activation for sulfide ores

    Institute of Scientific and Technical Information of China (English)

    HU Hui-ping; CHEN Qi-yuan; YIN Zhou-lan; HE Yue-hui; HUANG Bai-yun

    2007-01-01

    Structural changes for mechanically activated pyrite, sphalerite, galena and molybdenite with or without the exposure to ambient air, were systematically investigated using X-ray diffraction analysis(XRD), particle size analysis, gravimetrical method, X-ray photo-electron spectroscopy(XPS) and scanning electron microscopy(SEM), respectively. Based on the above structural changes for mechanically activated sulfide ores and related reports by other researchers, several qualitative rules of the mechanisms and the effects of mechanical activation for sulfide ores are obtained. For brittle sulfide ores with thermal instability, and incomplete cleavage plane or extremely incomplete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with thermal instability, and complete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed, and lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with excellent thermal stability, and complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For sulfide ores with high toughness, good thermal stability and very excellent complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation, but the lattice deformation ratio is very small. The effects of mechanical activation are worst.

  10. Sulfide as a soil phytotoxin - A review

    Directory of Open Access Journals (Sweden)

    Leon P M Lamers

    2013-07-01

    Full Text Available In wetland soils and underwater sediments of marine, brackish and freshwater systems, the strong phytotoxin sulfide may accumulate as a result of microbial reduction of sulfate during anaerobiosis, its level depending on prevailing edaphic conditions. In this review, we compare an extensive body of literature on phytotoxic effects of this reduced sulfur compound in different ecosystem types, and review the effects of sulfide at multiple ecosystem levels: the ecophysiological functioning of individual plants, plant-microbe associations, and community effects including competition and facilitation interactions. Recent publications on multi-species interactions in the rhizosphere show even more complex mechanisms explaining sulfide resistance. It is concluded that sulfide is a potent phytotoxin, profoundly affecting plant fitness and ecosystem functioning in the full range of wetland types including coastal systems, and at several levels. Traditional toxicity testing including hydroponic approaches generally neglect rhizospheric effects, which makes it difficult to extrapolate results to real ecosystem processes. To explain the differential effects of sulfide at the different organizational levels, profound knowledge about the biogeochemical, plant physiological and ecological rhizosphere processes is vital. This information is even more important, as anthropogenic inputs of sulfur into freshwater ecosystems and organic loads into freshwater and marine systems are still much higher than natural levels, and are steeply increasing in Asia. In addition, higher temperatures as a result of global climate change may lead to higher sulfide production rates in shallow waters.

  11. Mineralogy of Copper-Gold Deposit, Masjid Daghi Area, Jolfa, IRAN

    Science.gov (United States)

    Zenoozi, Roya

    2010-05-01

    The Copper-Gold deposit of Masjid Daghi area is located in the Jolfa quadrangle (scale 1:100,000), East Azerbaijan Province, north-west Iran. The deposit, hosting by sub-volcanic bodies comprise of quartz monzonite composition whose intruded the Tertiary volcanic and volcanic-sedimentary rocks and turbidities. The Tertiary volcanic rocks consist of andesite, trachy andesite and quartz andesite. These mineral-bearing bodies related to Late Eocene sub-volcanic activities which intrudded the Eocene volcanic rocks. Mineralography, XRD and SEM studies showed that the variations in mineralization of the area. The main agent of mineralization is the intrusion of Late Eocene sub volcanic bodies inside the Tertiary volcanic units. The mineralography studies revealed two main groups of mineralization as oxides and sulfides. The sulfide minerals formed as veins, vein lets and stock work.The economic minerals comprise of native gold, copper sulfides. The native gold occurring in siliceous veins and almost as inclusions inside the sulfides minerals such as chalcopyrite. The copper sulfides, contain pyrite, chalcopyrite and chalco-pyrrhoyite. Pyrite is main sulfide in the area and formed as disseminations, cavity filling and colloform. The amount of pyrite, chalcopyrite and chalco-pyrrhoyite increases with depth. Supergene alteration produced digenite, covellite, bornite, and malachite. The alteration occurred as potassic, phyllic, argillic and propylitic minerals. Furthermore, selective sercitic, sericitic-chloritic and alunitic alterations are seen around the mineralized veins. The mineralography studies indicate that pyrite is main mineral phase and native gold occurred in silicious vein almost as inclusions inside the sulfide mineral. Most of economic mineral formed as veins, vein lets, disseminated, cavity filling and colloform which related to intrusions of Late Eocene quartz monzonite bodies into the Eocene volcanic rocks and turbiditse. Some types of alterations such as

  12. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors.

    Science.gov (United States)

    Villa-Gomez, D K; Cassidy, J; Keesman, K J; Sampaio, R; Lens, P N L

    2014-03-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4(2-) ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing bioreactors. The sulfide was measured using a sulfide ion selective electrode (pS) and the values obtained were used to calculate proportional-integral-derivative (PID) controller parameters. The experiments were performed in an inverse fluidized bed bioreactor with automated operation using the LabVIEW software version 2009(®). A rapid response and high sulfide increment was obtained through a stepwise increase in the CODin concentration, while a stepwise decrease to the HRT exhibited a slower response with smaller sulfide increment. Irrespective of the way the OLR was decreased, the pS response showed a time-varying behavior due to sulfide accumulation (HRT change) or utilization of substrate sources that were not accounted for (CODin change). The pS electrode response, however, showed to be informative for applications in sulfate reducing bioreactors. Nevertheless, the recorded pS values need to be corrected for pH variations and high sulfide concentrations (>200 mg/L). Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors

    NARCIS (Netherlands)

    Villa Gomez, D.K.; Cassidy, J.; Keesman, K.J.; Sampaio, R.M.; Lens, P.N.L.

    2014-01-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4 2- ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing

  14. NEAR-CONTINUOUS MEASUREMENT OF HYDROGEN SULFIDE AND CARBONYL SULFIDE BY AN AUTOMATIC GAS CHROMATOGRAPH

    Science.gov (United States)

    An automatic gas chromatograph with a flame photometric detector that samples and analyzes hydrogen sulfide and carbonyl sulfide at 30-s intervals is described. Temperature programming was used to elute trace amounts of carbon disulfide present in each injection from a Supelpak-S...

  15. Hydrogen sulfide induces oxidative damage to RNA and DNA in a sulfide-tolerant marine invertebrate.

    Science.gov (United States)

    Joyner-Matos, Joanna; Predmore, Benjamin L; Stein, Jenny R; Leeuwenburgh, Christiaan; Julian, David

    2010-01-01

    Hydrogen sulfide acts as an environmental toxin across a range of concentrations and as a cellular signaling molecule at very low concentrations. Despite its toxicity, many animals, including the mudflat polychaete Glycera dibranchiata, are periodically or continuously exposed to sulfide in their environment. We tested the hypothesis that a broad range of ecologically relevant sulfide concentrations induces oxidative stress and oxidative damage to RNA and DNA in G. dibranchiata. Coelomocytes exposed in vitro to sulfide (0-3 mmol L(-1) for 1 h) showed dose-dependent increases in oxidative stress (as 2',7'-dichlorofluorescein fluorescence) and superoxide production (as dihydroethidine fluorescence). Coelomocytes exposed in vitro to sulfide (up to 0.73 mmol L(-1) for 2 h) also acquired increased oxidative damage to RNA (detected as 8-oxo-7,8-dihydroguanosine) and DNA (detected as 8-oxo-7,8-dihydro-2'-deoxyguanosine). Worms exposed in vivo to sulfide (0-10 mmol L(-1) for 24 h) acquired elevated oxidative damage to RNA and DNA in both coelomocytes and body wall tissue. While the consequences of RNA and DNA oxidative damage are poorly understood, oxidatively damaged deoxyguanosine bases preferentially bind thymine, causing G-T transversions and potentially causing heritable point mutations. This suggests that sulfide can be an environmental mutagen in sulfide-tolerant invertebrates.

  16. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors

    NARCIS (Netherlands)

    Villa Gomez, D.K.; Cassidy, J.; Keesman, K.J.; Sampaio, R.M.; Lens, P.N.L.

    2014-01-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4 2- ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing

  17. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs

    NARCIS (Netherlands)

    Klatt, Judith M.; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    2015-01-01

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2S: (i) H2S accelerated the recovery of

  18. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs

    NARCIS (Netherlands)

    Klatt, Judith M.; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2S: (i) H2S accelerated the recovery of

  19. sulfide – reality or fantasy?

    Directory of Open Access Journals (Sweden)

    Paulina Brodek

    2016-08-01

    Full Text Available Hydrogen sulfide (H2S is a signaling gasotransmitter, involved in different physiological and pathological processes. H2S regulates apoptosis, the cell cycle and oxidative stress. H2S exerts powerful effects on smooth muscle cells, endothelial cells, inflammatory cells, endoplasmic reticulum, mitochondria and nuclear transcription factors. H2S is known to be produced from L-cysteine, D-cysteine and L-homocysteine in the body. Four enzymes – cystathionine-b synthase (CBS, mercaptopyruvate sulfurtransferase (3-MST, cystathionine-γ lyase (CSE and cysteine aminotransferase (CAT – are involved in H2S synthesis. The biosynthetic pathway for the production of H2S from D-cysteine involves 3-MST and D-amino acid oxidase (DAO. The therapeutic potential of H2S is not clear. However, recently results have demonstrated that H2S has protective action for ischemic heart disease or hypertension, and protects against ischemia of the brain. This review summarizes the negative and the positive roles of H2S in various biological systems, for example the cardiovascular system and nervous system. We also discuss the function of classical, therapeutic and natural (for example garlic donors of H2S in pre-clinical and clinical studies.

  20. Thermal decomposition of mercuric sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Leckey, J.H.; Nulf, L.E.

    1994-10-28

    The rate of thermal decomposition of mercuric sulfide (HgS) has been measured at temperatures from 265 to 345 C. These data have been analyzed using a first-order chemical reaction model for the time dependence of the reaction and the Arrhenius equation for the temperature dependence of the rate constant. Using this information, the activation energy for the reaction was found to be 55 kcal/mol. Significant reaction vessel surface effects obscured the functional form of the time dependence of the initial portion of the reaction. The data and the resulting time-temperature reaction-rate model were used to predict the decomposition rate of HgS as a function of time and temperature in thermal treatment systems. Data from large-scale thermal treatment studies already completed were interpreted in terms of the results of this study. While the data from the large-scale thermal treatment studies were consistent with the data from this report, mass transport effects may have contributed to the residual amount of mercury which remained in the soil after most of the large-scale runs.

  1. Indium sulfide buffer/CIGSSe interface engineering: Improved cell performance by the addition of zinc sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Allsop, N.A. [Hahn-Meitner-Institut Berlin, Department SE2, Glienicker Str. 100, D-14109 Berlin (Germany)]. E-mail: allsop@hmi.de; Camus, C. [Hahn-Meitner-Institut Berlin, Department SE2, Glienicker Str. 100, D-14109 Berlin (Germany); Haensel, A. [Hahn-Meitner-Institut Berlin, Department SE2, Glienicker Str. 100, D-14109 Berlin (Germany); Gledhill, S.E. [Hahn-Meitner-Institut Berlin, Department SE2, Glienicker Str. 100, D-14109 Berlin (Germany); Lauermann, I. [Hahn-Meitner-Institut Berlin, Department SE2, Glienicker Str. 100, D-14109 Berlin (Germany); Lux-Steiner, M.C. [Hahn-Meitner-Institut Berlin, Department SE2, Glienicker Str. 100, D-14109 Berlin (Germany); Fischer, Ch.-H. [Hahn-Meitner-Institut Berlin, Department SE2, Glienicker Str. 100, D-14109 Berlin (Germany)

    2007-05-31

    Indium sulfide buffer layers deposited by the spray-ion layer gas reaction (Spray-ILGAR) technique are a viable alternative to the traditional cadmium sulfide buffer layer in thin film solar cells. In the present work we report on the results of manipulating the absorber/buffer interface between the chalcopyrite Cu(In,Ga)(S,Se){sub 2} absorber (CIGSSe) and the indium sulfide buffer. It is shown that the deposition of a small amount of zinc sulfide at the absorber/buffer interface can be used to increase the open circuit voltage. A small but significant increase of 20 mV (up to 580 mV), as compared to the pure indium sulfide buffered cells is possible leading to an increase in the overall efficiency.

  2. What processes at mid-ocean ridges tell us about volcanogenic massive sulfide deposits

    Science.gov (United States)

    Cathles, Lawrence M.

    2011-07-01

    Episodic seafloor spreading, ridge topography, and fault movement at ridges find (more extreme) analogs in the arc and back-arc setting where the volcanogenic massive sulfide (VMS) deposits that we mine today were formed. The factors affecting sulfide accumulation efficiency and the extent to which sulfides are concentrated spatially are the same in both settings, however. The processes occurring at mid-ocean ridges therefore provide a useful insight into those producing VMS deposits in arcs and back-arcs. The critical observation investigated here is that all the heat introduced by seafloor spreading at mid-ocean ridges is carried out of the crust within a few hundred meters of the ridge axis by ˜350°C hydrothermal fluids. The high-temperature ridge hydrothermal systems are tied to the presence of magma at the ridge axis and greatly reduce the size and control the shape of axial magma intrusions. The amount of heat introduced to each square kilometer of ocean crust during its formation can be calculated, and its removal by high-temperature convection allows calculation of the total base metal endowment of the ocean basins. Using reasonable metal deposition efficiencies, we conclude that the ocean floor is a giant VMS district with metal resources >600 times the total known VMS reserves on land and a copper resource which would last >6,000 years at current production rates.

  3. Reduction of acid rock drainage using steel slag in cover systems over sulfide rock waste piles.

    Science.gov (United States)

    de Almeida, Rodrigo Pereira; Leite, Adilson do Lago; Borghetti Soares, Anderson

    2015-04-01

    The extraction of gold, coal, nickel, uranium, copper and other earth-moving activities almost always leads to environmental damage. In metal and coal extraction, exposure of sulfide minerals to the atmosphere leads to generation of acid rock drainage (ARD) and in underground mining to acid mine drainage (AMD) due to contamination of infiltrating groundwater. This study proposes to develop a reactive cover system that inhibits infiltration of oxygen and also releases alkalinity to increase the pH of generated ARD and attenuate metal contaminants at the same time. The reactive cover system is constructed using steel slag, a waste product generated from steel industries. This study shows that this type of cover system has the potential to reduce some of the adverse effects of sulfide mine waste disposal on land. Geochemical and geotechnical characterization tests were carried out. Different proportions of sulfide mine waste and steel slag were studied in leachate extraction tests. The best proportion was 33% of steel slag in dry weight. Other tests were conducted as follows: soil consolidation, saturated permeability and soil water characteristic curve. The cover system was numerically modeled through unsaturated flux analysis using Vadose/w. The solution proposed is an oxygen transport barrier that allows rain water percolation to treat the ARD in the waste rock pile. The results showed that the waste pile slope is an important factor and the cover system must have 5 m thickness to achieve an acceptable effectiveness.

  4. State-of-the-art hydrogen sulfide control for geothermal energy systems: 1979

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, F.B.; Hill, J.H.; Phelps, P.L. Jr.

    1980-03-01

    Existing state-of-the-art technologies for removal of hydrogen sulfide are discussed along with a comparative assessment of their efficiencies, reliabilities and costs. Other related topics include the characteristics of vapor-dominated and liquid-dominated resources, energy conversion systems, and the sources of hydrogen sulfide emissions. It is indicated that upstream control technologies are preferred over downsteam technologies primarily because upstream removal of hydrogen sulfide inherently controls all downstream emissions including steam-stacking. Two upstream processes for vapor-dominated resources appear promising; the copper sulfate (EIC) process, and the steam converter (Coury) process combined with an off-gas abatement system such as a Stretford unit. For liquid-dominated systems that produce steam, the process where the non-condensible gases are scrubbed with spent geothermal fluid appears to be promising. An efficient downstream technology is the Stretford process for non-condensible gas removal. In this case, partitioning in the surface condenser will determine the overall abatement efficiency. Recommendations for future environmental control technology programs are included.

  5. Removal Of Volatile Impurities From Copper Concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, L.; Schuler, A.; Frei, A.; Sturzenegger, M.

    2005-03-01

    To study the removal of volatile impurities from two different copper concentrates they have been heated on a thermo balance to temperatures between 900 and 1500 C. This sample treatment revealed that both concentrates undergo strong weight losses at 500 and 700 C. They were attributed to the removal of sulfur. Elemental analyses of the residues by ICP spectrometry have shown that the thermal treatment efficiently removes the volatile impurities. Already below 900 C most of the arsenic is removed by evaporation, the largest fraction of lead and zinc is removed in the temperature interval of 1300-1500 C. It was observed that quartz in the concentrate leads to the formation of a silicon-enriched phase besides a metal rich sulfide phase. The former is interpreted as an early stage of a silicate slag. Elemental analysis showed that the formation of this distinct slag phase does not hinder the efficient removal of volatile impurities. (author)

  6. Sulfide capacities of fayalite-base slags

    Science.gov (United States)

    Simeonov, S. R.; Sridhar, R.; Toguri, J. M.

    1995-04-01

    The sulfide capacities of fayalite-base slags were measured by a gas-slag equilibration technique under controlled oxygen and sulfur potentials similar to those encountered in the pyrometallurgical processing of nonferrous metals. The oxygen pressure range was from 10-9.5 to 10-11 MPa and the sulfur pressure range from 10-3 to 10-4.5 MPa, over a temperature range of 1473 to 1623 K. The slags studied were FeO-SiO2 at silica saturation and those with addition of CaO, MgO, and Al2O3 to determine their effect on sulfide capacities. For these slags, the sulfide capacities were found to vary from 10-3.3 to 10-5. The sulfide capacities increased with increasing temperature from 1473 to 1623 K. A comparison of the reported plant data on sulfur content of industrial slags shows good agreement with the present experimental results. The present data will be useful in estimating metal losses in slag due to metal sulfide entrainment in nonferrous smelters.

  7. Hydrogen sulfide: neurochemistry and neurobiology.

    Science.gov (United States)

    Qu, K; Lee, S W; Bian, J S; Low, C-M; Wong, P T-H

    2008-01-01

    Current evidence suggests that hydrogen sulfide (H2S) plays an important role in brain functions, probably acting as a neuromodulator as well as an intracellular messenger. In the mammalian CNS, H2S is formed from the amino acid cysteine by the action of cystathionine beta-synthase (CBS) with serine (Ser) as the by-product. As CBS is a calcium and calmodulin dependent enzyme, the biosynthesis of H2S should be acutely controlled by the intracellular concentration of calcium. In addition, it is also regulated by S-adenosylmethionine which acts as an allosteric activator of CBS. H2S, as a sulfhydryl compound, has similar reducing properties as glutathione. In neurons, H2S stimulates the production of cAMP probably by direct activation of adenylyl cyclase and thus activate cAMP-dependent processes. In astrocytes, H2S increases intracellular calcium to an extent capable of inducing and propagating a "calcium wave", which is a form of calcium signaling among these cells. Possible physiological functions of H2S include potentiating long-term potentials through activation of the NMDA receptors, regulating the redox status, maintaining the excitatory/inhibitory balance in neurotransmission, and inhibiting oxidative damage through scavenging free radicals and reactive species. H2S is also involved in CNS pathologies such as stroke and Alzheimer's disease. In stroke, H2S appears to act as a mediator of ischemic injuries and thus inhibition of its production has been suggested to be a potential treatment approach in stroke therapy.

  8. Handling of Copper and Copper Oxide Nanoparticles by Astrocytes.

    Science.gov (United States)

    Bulcke, Felix; Dringen, Ralf

    2016-02-01

    Copper is an essential trace element for many important cellular functions. However, excess of copper can impair cellular functions by copper-induced oxidative stress. In brain, astrocytes are considered to play a prominent role in the copper homeostasis. In this short review we summarise the current knowledge on the molecular mechanisms which are involved in the handling of copper by astrocytes. Cultured astrocytes efficiently take up copper ions predominantly by the copper transporter Ctr1 and the divalent metal transporter DMT1. In addition, copper oxide nanoparticles are rapidly accumulated by astrocytes via endocytosis. Cultured astrocytes tolerate moderate increases in intracellular copper contents very well. However, if a given threshold of cellular copper content is exceeded after exposure to copper, accelerated production of reactive oxygen species and compromised cell viability are observed. Upon exposure to sub-toxic concentrations of copper ions or copper oxide nanoparticles, astrocytes increase their copper storage capacity by upregulating the cellular contents of glutathione and metallothioneins. In addition, cultured astrocytes have the capacity to export copper ions which is likely to involve the copper ATPase 7A. The ability of astrocytes to efficiently accumulate, store and export copper ions suggests that astrocytes have a key role in the distribution of copper in brain. Impairment of this astrocytic function may be involved in diseases which are connected with disturbances in brain copper metabolism.

  9. The copper-nickel concentration log: A tool for stratigraphic interpretation within the ultramafic and basal zones of the stillwater complex, Montana

    Science.gov (United States)

    Drew, L.J.; Bawiec, W.J.; Page, N.J.; Schuenemeyer, J.H.

    1985-01-01

    An analogue to the electric well log was devised for copper-nickel concentration drill-hole data from the Basal and lower part of the Ultramafic zones of the Stillwater Complex using automated data processing. The copper-nickel concentration logs graphically represent intensity (concentration) values that reflect the distribution of the elements in sulfide and silicate minerals. Four major patterns are recognized by their characteristic variations in copper and nickel intensity: (1) relatively flat, low-level copper-intensity signatures associated with arcuate nickel-intensity patterns that correlate with rocks in the Peridotite member of the Ultramafic zone; (2) arcuate or bulb-like patterns of copper and nickel intensity that correlate closely with the Basal bronzite cumulate member of the Basal zone; (3) complex patterns consisting of intervals of low-intensity copper and moderate-intensity nickel, spikes of high nickel and copper intensity, and high copper intensity associated with low nickel intensity that correlate respectively with cordierite-pyroxene hornfels, massive sulfide, norites and mineralized diabase dikes in the Basal norite member; and (4) large intervals of extremely low copper and nickel intensity that correlate with quartz-orthopyroxene hornfels. The recognition and interpretation of these patterns allow two- and three-dimensional stratigraphic and lithologic reconstructions to be done by means of concentration-log correlations instead of variable quality lithologic logging. ?? 1985.

  10. Canine models of copper toxicosis for understanding mammalian copper metabolism

    OpenAIRE

    Fieten, Hille; Leegwater, Peter A. J.; Watson, Adrian L.; Rothuizen, Jan

    2011-01-01

    Hereditary forms of copper toxicosis exist in man and dogs. In man, Wilson’s disease is the best studied disorder of copper overload, resulting from mutations in the gene coding for the copper transporter ATP7B. Forms of copper toxicosis for which no causal gene is known yet are recognized as well, often in young children. Although advances have been made in unraveling the genetic background of disorders of copper metabolism in man, many questions regarding disease mechanisms and copper homeo...

  11. Hair copper in intrauterine copper device users.

    Science.gov (United States)

    Thiery, M; Heyndrickx, A; Uyttersprot, C

    1984-03-01

    The antifertility effect of copper-bearing IUDs is based on continuous release of copper, which is a result of the reaction between the metal and the uterine secretions. Released cupric ions collect in the endometrium and in the uterine fluid but significant accumulation has not been found in the bloodstream or elsewhere. Following Laker's suggestion that hair be used for monitoring essential trace elements, e.g., copper, we checked the copper content of the hair of women wearing copper-bearing IUDs. Samples of untreated pubic hair removed by clipping before diagnostic curettage were obtained from 10 young (24-34 years old), white caucasian females who until then had been wearing an MLCu250 IUD for more than 1 year. Pubes from 10 comparable (sex, age, race) subjects who had never used a Cu-containing device served as controls. The unwashed material was submitted to the toxicology laboratory, where the copper content was assessed by flameless atomic absorption, a technique whose lower limit of measurement lies at a concentration of 0.05 mcg Cu/ml fluid (50 ppb). Hair samples were washed to remove extraneous traces of metal according to the prescriptions of the International Atomic Energy Agency, weighed, and mineralized, after which a small volume (10 mcl) of the diluted fluid was fed into the graphite furnace. Each sample (75-150 mg) was analyzed 4 times, both before and after washing. Since the cleaning procedure reduces the weight of the sample (mainly by the removal of fat, dust, etc.) this explains why the percentage copper content of washed hair is higher than that of unwashed hair belonging to the same subject. The results indicate that there was no significant difference (Mann-Whitney U test) between the mean copper levels of both unwashed and washed pubes from women who were using or had never used an MLCu250 IUD. We therefore conclude that the use of this copper-containing device is not associated with significant accumulation of copper in (pubic) hair.

  12. Sulfide and methane production in sewer sediments.

    Science.gov (United States)

    Liu, Yiwen; Ni, Bing-Jie; Ganigué, Ramon; Werner, Ursula; Sharma, Keshab R; Yuan, Zhiguo

    2015-03-01

    Recent studies have demonstrated significant sulfide and methane production by sewer biofilms, particularly in rising mains. Sewer sediments in gravity sewers are also biologically active; however, their contribution to biological transformations in sewers is poorly understood at present. In this study, sediments collected from a gravity sewer were cultivated in a laboratory reactor fed with real wastewater for more than one year to obtain intact sediments. Batch test results show significant sulfide production with an average rate of 9.20 ± 0.39 g S/m(2)·d from the sediments, which is significantly higher than the areal rate of sewer biofilms. In contrast, the average methane production rate is 1.56 ± 0.14 g CH4/m(2)·d at 20 °C, which is comparable to the areal rate of sewer biofilms. These results clearly show that the contributions of sewer sediments to sulfide and methane production cannot be ignored when evaluating sewer emissions. Microsensor and pore water measurements of sulfide, sulfate and methane in the sediments, microbial profiling along the depth of the sediments and mathematical modelling reveal that sulfide production takes place near the sediment surface due to the limited penetration of sulfate. In comparison, methane production occurs in a much deeper zone below the surface likely due to the better penetration of soluble organic carbon. Modelling results illustrate the dependency of sulfide and methane productions on the bulk sulfate and soluble organic carbon concentrations can be well described with half-order kinetics.

  13. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    Science.gov (United States)

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  14. China Copper Processing Industry Focus

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>1. Market Consumption The ’China Factor’ and Copper Price Fluctuation We all know China is an enormous consumer of copper,but the exact levels of consumption and where the copper has gone remains a mystery.

  15. Biogenic nanoparticles: copper, copper oxides, copper sulphides, complex copper nanostructures and their applications.

    Science.gov (United States)

    Rubilar, Olga; Rai, Mahendra; Tortella, Gonzalo; Diez, Maria Cristina; Seabra, Amedea B; Durán, Nelson

    2013-09-01

    Copper nanoparticles have been the focus of intensive study due to their potential applications in diverse fields including biomedicine, electronics, and optics. Copper-based nanostructured materials have been used in conductive films, lubrification, nanofluids, catalysis, and also as potent antimicrobial agent. The biogenic synthesis of metallic nanostructured nanoparticles is considered to be a green and eco-friendly technology since neither harmful chemicals nor high temperatures are involved in the process. The present review discusses the synthesis of copper nanostructured nanoparticles by bacteria, fungi, and plant extracts, showing that biogenic synthesis is an economically feasible, simple and non-polluting process. Applications for biogenic copper nanoparticles are also discussed.

  16. Corrosion of copper base alloys in a geothermal brine. SPE Paper No. 7881

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.L.

    1979-01-01

    The geothermal environment and the experimental procedures and schedules for corrosion tests of copper-base alloys are described. Corrosive attack on these materials was mostly uniform. Some selective leaching of alloying elements was observed, as was crevice corrosion, but the extent of these forms of corrosion was minor. The results of these tests show a trend toward higher corrosion rates with increasing copper content, for the brass alloys. Commercially pure copper, however, showed corrosion rates 20 to 30% of that suggested by the trend in the data. One copper--nickel alloy was tested to verify earlier test data; this alloy showed a corrosion rate about six times that of a brass of similar copper content. The primary agent of the corrosive attack was hydrogen sulfide, present in the water in trace amounts. The primary conclusion from these tests is that copper--zinc alloys are the most economical materials for boiler and preheater construction. The recommendation is made that materials be selected from these brasses: naval brass, yellow brass, admiralty brass, and copper, in this order of decreasing desirability. Aluminum brass and red brass are marginally acceptable. Copper--nickel alloys are unacceptable for boiler and preheater heat exchangers.

  17. Development of regenerable copper-based sorbents for hot gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B.; Hill, A.H. [Inst. of Gas Technology, Des Plaines, IL (United States); Honea, F.I. [Illinois Clean Coal Inst., Carbondale, IL (United States)

    1996-12-31

    The implementation of hot gas cleanup systems heavily depends on the development of regenerable sorbents for removal of sulfur-containing species (mainly H{sub 2}S) from the fuel gas stream at elevated temperatures (i.e., >350 C) from levels of several thousand ppm down to a few ppm, over many sulfidation/regeneration cycles. In addition, these sorbents must have high sulfur capacity, good sulfidation kinetics, good mechanical strength, and good chemical and structural stability over multicycle testing. Zinc-based sorbents, such as zinc titanates, are the leading contenders for hot gas desulfurization. However, these sorbents have been shown to suffer from zinc volatilization at elevated temperatures, resulting in sorbent deterioration and losses through attrition, loss of reactivity, leading to increasing sorbent replacement costs and overall cost of electricity. Copper-based sorbents do not suffer from volatilization problems due to the high melting point of the metal. However, bulk copper oxide is easily reduced to elemental copper in a reducing fuel gas environment, which in turn results in insufficient level of desulfurization. Fortunately, the sorbent desulfurization performance can be greatly enhanced by combining copper oxide with other oxides to minimize or prevent sorbent reduction during the sulfidation stage. This paper reports on research conducted to-date on the development of copper-based sorbents for hot coal gas desulfurization. The results of packed-bed experiments carried out for the determination of optimum operating conditions and for the evaluation of the long-term durability and regenerability of selected copper chromite sorbents are presented and discussed.

  18. Development of novel copper-based sorbents for hot-gas cleanup. Technical report, 1 March--31 May 1994

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Hill, A.H. [Inst. of Gas Technology, Chicago, IL (United States); Flytzani-Stephanopoulos, M.; Li, Z. [Tufts Univ., Medford, MA (United States)

    1994-09-01

    The objective of this investigation is to evaluate two novel copper-based sorbents, namely copper-chromium and copper-cerium, for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650 to 850 C. Such high temperatures will be required for the new generation of gas turbines (inlet > 750 C) in Integrated Gasification Combined Cycle (IGCC) systems. Results of fixed-bed reactor tests conducted in this quarter, indicate that, at 750 C, pre-reduction with H{sub 2} in the presence of H{sub 2}O does not effect the performance of either sorbent for H{sub 2}S removal. For the pre-reduced CuCr{sub 2}O{sub 4} sorbent, copper utilization before the first H{sub 2}S breakthrough is substantially higher in synthesis feed gas mixture than in feed gas containing 30 Vol% H{sub 2}, and slightly lower than in 10 vol% H{sub 2}. In sulfidation-regeneration testing of copper- and additive-rich sorbents, chromium-rich CuO-3Cr{sub 2}O{sub 4} sorbent demonstrated very high H{sub 2}S removal efficiency and high copper conversion levels (comparable to that of the 1:1 molar composition sorbent). Similar results were obtained with the cerium-rich CuO-3CeO{sub 2} sorbent, but only for the first cycle. The H{sub 2}S removal performance of both copper-rich sorbents was inferior to that of the respective 1:1 molar compositions. CuO-CeO{sub 2} sorbent testing in a TGA indicates no appreciable decrease in the sulfidation rate over 5 1/2 cycles. However, weight changes during regeneration of the CuO-CeO{sub 2} suggest that some copper or cerium sulfates formed.

  19. Acute inhalation toxicity of carbonyl sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.; Hahn, F.F.; Barr, E.B. [and others

    1995-12-01

    Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

  20. Modeling of Sulfide Microenvironments on Mars

    Science.gov (United States)

    Schwenzer, S. P.; Bridges, J. C.; McAdam, A.; Steer, E. D.; Conrad, P. G.; Kelley, S. P.; Wiens, R. C.; Mangold, N.; Grotzinger, J.; Eigenbrode, J. L.; Franz, H. B.; Sutter, B.

    2016-01-01

    Yellowknife Bay (YKB; sol 124-198) is the second site that the Mars Science Laboratory Rover Curiosity investigated in detail on its mission in Gale Crater. YKB represents lake bed sediments from an overall neutral pH, low salinity environment, with a mineralogical composition which includes Ca-sulfates, Fe oxide/hydroxides, Fe-sulfides, amorphous material, and trioctahedral phyllosilicates. We investigate whether sulfide alteration could be associated with ancient habitable microenvironments in the Gale mudstones. Some textural evidence for such alteration may be pre-sent in the nodules present in the mudstone.

  1. Iron-sulfide crystals in probe deposits

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming

    1998-01-01

    Iron-sulfides were observed in deposits collected on a probe inserted at the top of the furnace of a coal-fired power station in Denmark. The chemical composition of the iron-sulfides is equivalent to pyrrhotite (FeS). The pyrrhotites are present as crystals and, based on the shape of the crystals......, it was deduced that they were not deposited but instead grew within the deposit. The presence of unburned char particles within the deposits supports the concept that a reducing environment existed in the deposits. Two processes are proposed for explaining the existence of pyrrhotite crystals within a deposit...

  2. Use of biogenic sulfide for ZnS precipitation

    NARCIS (Netherlands)

    Esposito, G.; Veeken, A.; Weijma, J.; Lens, P.N.L.

    2006-01-01

    A 600 ml continuously stirred tank reactor was used to assess the performance of a zinc sulfide precipitation process using a biogenic sulfide solution (the effluent of a sulfate-reducing bioreactor) as sulfide source. In all experiments, a proportional-integral (PI) control algorithm was used to co

  3. A physiologically based kinetic model for bacterial sulfide oxidation

    NARCIS (Netherlands)

    Klok, J.B.; Graaff, M. de; Bosch, P.L. van den; Boelee, N.C.; Keesman, K.J.; Janssen, A.J.W.M.

    2013-01-01

    In the biotechnological process for hydrogen sulfide removal from gas streams, a variety of oxidation products can be formed. Under natron-alkaline conditions, sulfide is oxidized by haloalkaliphilic sulfide oxidizing bacteria via flavocytochrome c oxidoreductase. From previous studies, it was concl

  4. A study of the trace sulfide mineral assemblages in the Stillwater Complex, Montana, USA

    Science.gov (United States)

    Aird, Hannah M.; Ferguson, Katherine M.; Lehrer, Malia L.; Boudreau, Alan E.

    2017-03-01

    The sulfide assemblages of the Stillwater Complex away from the well-studied ore zones are composed mainly of variable proportions of pyrrhotite, chalcopyrite, pentlandite, and ±pyrite. Excluding vein assemblages and those affected by greenschist and lower temperature alteration, the majority can be classified into two broad assemblages, defined here as pristine (multiphase, often globular in shape) or volatile-bearing (multiphase, high-temperature, volatile-rich minerals such as biotite, hornblende, or an unmixed calcite-dolomite assemblage). The volatile-bearing assemblages are mainly found within and below the J-M reef, where native copper and sphalerite are also locally present. Pristine sulfides are found throughout the stratigraphy. Both groups can be affected by apparent S loss in the form of pyrite being converted to magnetite and chalcopyrite to a Cu-Fe-oxide (delafossite), with little to no silicate alteration. An upward trend from pentlandite-rich to pyrrhotite-rich to pyrite-rich assemblages is observed in the footwall rocks in upper GN-I, and the same trend repeats from just below the reef and continues into the overlying N-II and GN-II. Modeling suggests that the sulfide Ni in the Peridotite Zone is largely controlled by silicate Ni. When taken together, observations are most readily explained by the remobilization of selected elements by a high-temperature fluid with the apparent loss of S > Cu > Ni. This could concentrate ore metals by vapor refining, eventually producing a platinum group element-enriched sulfide ore zone, such as the J-M reef.

  5. A study of the trace sulfide mineral assemblages in the Stillwater Complex, Montana, USA

    Science.gov (United States)

    Aird, Hannah M.; Ferguson, Katherine M.; Lehrer, Malia L.; Boudreau, Alan E.

    2016-07-01

    The sulfide assemblages of the Stillwater Complex away from the well-studied ore zones are composed mainly of variable proportions of pyrrhotite, chalcopyrite, pentlandite, and ±pyrite. Excluding vein assemblages and those affected by greenschist and lower temperature alteration, the majority can be classified into two broad assemblages, defined here as pristine (multiphase, often globular in shape) or volatile-bearing (multiphase, high-temperature, volatile-rich minerals such as biotite, hornblende, or an unmixed calcite-dolomite assemblage). The volatile-bearing assemblages are mainly found within and below the J-M reef, where native copper and sphalerite are also locally present. Pristine sulfides are found throughout the stratigraphy. Both groups can be affected by apparent S loss in the form of pyrite being converted to magnetite and chalcopyrite to a Cu-Fe-oxide (delafossite), with little to no silicate alteration. An upward trend from pentlandite-rich to pyrrhotite-rich to pyrite-rich assemblages is observed in the footwall rocks in upper GN-I, and the same trend repeats from just below the reef and continues into the overlying N-II and GN-II. Modeling suggests that the sulfide Ni in the Peridotite Zone is largely controlled by silicate Ni. When taken together, observations are most readily explained by the remobilization of selected elements by a high-temperature fluid with the apparent loss of S > Cu > Ni. This could concentrate ore metals by vapor refining, eventually producing a platinum group element-enriched sulfide ore zone, such as the J-M reef.

  6. Analysis of copper corrosion in compacted bentonite clay as a function of clay density and growth conditions for sulfate-reducing bacteria.

    Science.gov (United States)

    Pedersen, K

    2010-03-01

    To investigate the relationships between sulfate-reducing bacteria (SRB), growth conditions, bentonite densities and copper sulfide generation under circumstances relevant to underground, high-level radioactive waste repositories. Experiments took place 450 m underground, connected under in situ pressure to groundwater containing SRB. The microbial reduction of sulfate to sulfide and subsequent corrosion of copper test plates buried in compacted bentonite were analysed using radioactive sulfur (35SO4(2-)) as tracer. Mass distribution of copper sulfide on the plates indicated a diffusive process. The relationship between average diffusion coefficients (Ds) and tested density (rho) was linear. Ds (m2 s(-1))=-0.004xrho (kg m(-3))+8.2, decreasing by 0.2 Ds units per 50 kg m(-3) increase in density, from 1.2x10(-11) m2 s(-1) at 1750 kg m(-3) to 0.2x10(-11) m2 s(-1) at 2000 kg m(-3). It is possible that sulfide corrosion of waste canisters in future radioactive waste repositories depends mainly on sulfide concentration at the boundary between groundwater and the buffer, which in turn depends on SRB growth conditions (e.g., sulfate accessibility, carbon availability and electron donors) and geochemical parameters (e.g., presence of ferrous iron, which immobilizes sulfide). Maintaining high bentonite density is also important in mitigating canister corrosion. The sulfide diffusion coefficients can be used in safety calculations regarding waste canister corrosion. The work supports findings that microbial activity in compacted bentonite will be restricted. The study emphasizes the importance of growth conditions for sulfate reduction at the groundwater boundary of the bentonite buffer and linked sulfide production.

  7. Influence of hydrogen sulfide annealing on copper-zinc-tin-sulfide solar cells sputtered from a quaternary compound target

    Energy Technology Data Exchange (ETDEWEB)

    Bras, Patrice, E-mail: patrice.bras@angstrom.uu.se [Midsummer AB, Elektronikhöjden 6, SE-17543 Järfälla (Sweden); Solid State Electronics, Uppsala University, Box 534, 75121 Uppsala (Sweden); Sterner, Jan, E-mail: jan.sterner@midsummer.se [Midsummer AB, Elektronikhöjden 6, SE-17543 Järfälla (Sweden); Platzer-Björkman, Charlotte, E-mail: charlotte.platzer@angstrom.uu.se [Solid State Electronics, Uppsala University, Box 534, 75121 Uppsala (Sweden)

    2015-05-01

    With a theoretical efficiency around 30% and an optimized band gap for sunlight absorption, Cu{sub 2}ZnSnS{sub 4} (CZTS) is a promising, earth-abundant, material for thin film solar cells. Sputtering CZTS from a quaternary compound target is a quick and potentially industrial-scaled process that has not been investigated deeply yet. Our approach is based on an in-line vacuum system for the complete device. CZTS is sputtered from a compound target on a sodium molybdate (MoNa) pre-sputtered stainless steel substrate, and then annealed in high-pressure H{sub 2}S atmosphere. A 1 μm thick absorber is obtained within 7 minute sputtering. Top layers are then deposited, without vacuum breaking. The effects of different annealing temperatures on the absorber morphology and composition are investigated. It is observed that recrystallization already occurs at 420 °C and that crystallinity improves with increasing temperature up to 550 °C. However, micro-sphere formation underneath the film degrades the corresponding solar cell performance dramatically above 510 °C. It is shown that sodium is needed in order to enhance recrystallization of CZTS but the MoNa layer thickness seems not to be a critical parameter. Scanning electron microscopy, X-ray diffraction, X-ray fluorescence and current-voltage measurement were used to characterize the samples. - Highlights: • CZTS sputtered from a quaternary compound target for solar cell fabrication • In-line vacuum tool for the complete device • Increasing crystallinity with sodium incorporation and annealing temperature up to 550 °C • Best device exhibits 4.2% efficiency.

  8. Effect of the cooling rate on the phase composition and structure of copper matte converting slags

    Science.gov (United States)

    Selivanov, E. N.; Gulyaeva, R. I.; Udoeva, L. Yu.; Belyaev, V. V.; Pankratov, A. A.

    2009-08-01

    The effect of the cooling rate on the phase composition and microstructure of copper matte converting slags is studied by X-ray diffraction, combined thermogravimetry and calorimetry, mineragraphy, and electron-probe microanalysis. The compositions of oxide and sulfide phases are determined, and the forms of nonferrous metals in slags cooled at a rate of 0.3 and 900°C/s are revealed. At high cooling rates of the slags, iron silicate glass is shown to form apart from sulfide phases. Repeated heating of the slags leads to the development of devitrification, “cold” crystallization, and melting. A decrease in the cooling rate favors an increase in the grain sizes in oxides (magnetite, iron silicates) and sulfides (bornite-, sphalerite, and galena-based solid solutions).

  9. Digenite Nanosheets Synthesized by Thermolysis of Layered Copper-Alkanethiolate Frameworks.

    Science.gov (United States)

    Bryks, Whitney; Lupi, Eduardo; Ngo, Charles; Tao, Andrea R

    2016-10-06

    Copper sulfide nanocrystals support localized surface plasmon resonances in the near-infrared wavelengths and have significant potential as active plasmonic nanomaterials due to the tunability of this optical response. While numerous strategies exist for synthesizing copper sulfide nanocrystals, few methods result in nanocrystals with both controlled morphological shapes and crystallinity. Here, we synthesize and characterize ultrathin (thermolysis, utilizing Cu alkanethiolates as single-source precursors. Layered Cu alkanethiolate precursors adopt a highly ordered structure which can be further stabilized in the presence of Cl(-) and also serve to template the formation of nanosheets. We show that, in the absence of Cl(-), only isotropic and disk-like Cu2-xS nanocrystals form. These findings offer further insight into the use of layered metal-organic single-source precursors as templates for anisotropic nanocrystal growth.

  10. Using surface plasmon resonances to test the durability of silver copper films

    Science.gov (United States)

    Bussjager, Rebecca J.; MacLeod, H. Angus

    1996-09-01

    Silver has high reflectivity in the visible and infrared but cannot be used fully because of its distressing lack of durability. A technique that uses the surface plasmon resonance phenomenon offers a sensitive method for studying the corrosion of silver and assessing improvements. It has been used in the investigation of the effects of flashing a thin layer, approximately 1 nm thick, of copper over silver in an attempt at cathodic protection. Tests include exposing silver and silver-copper films to air, 94% relative humidity, water, and hydrogen sulfide.

  11. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices.

    NARCIS (Netherlands)

    Tangerman, A.

    2009-01-01

    This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (-SH

  12. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices

    NARCIS (Netherlands)

    Tangerman, Albert

    2009-01-01

    This review deals with the measurement of the volatile Sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (-SH

  13. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices

    NARCIS (Netherlands)

    Tangerman, Albert

    2009-01-01

    This review deals with the measurement of the volatile Sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol

  14. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices.

    NARCIS (Netherlands)

    Tangerman, A.

    2009-01-01

    This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol

  15. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco

    DEFF Research Database (Denmark)

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild

    2015-01-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree...... such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers...... (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit...

  16. Copper and silver halates

    CERN Document Server

    Woolley, EM; Salomon, M

    2013-01-01

    Copper and Silver Halates is the third in a series of four volumes on inorganic metal halates. This volume presents critical evaluations and compilations for halate solubilities of the Group II metals. The solubility data included in this volume are those for the five compounds, copper chlorate and iodate, and silver chlorate, bromate and iodate.

  17. Coping with copper

    DEFF Research Database (Denmark)

    Nunes, Ines; Jacquiod, Samuel; Brejnrod, Asker

    2016-01-01

    Copper has been intensively used in industry and agriculture since mid-18(th) century and is currently accumulating in soils. We investigated the diversity of potential active bacteria by 16S rRNA gene transcript amplicon sequencing in a temperate grassland soil subjected to century-long exposure......, suggesting a potential promising role as bioindicators of copper contamination in soils....

  18. Monitoring sulfide and sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, R.S.

    1995-12-31

    Simple yet precise and accurate methods for monitoring sulfate-reducing bacteria (SRB) and sulfide remain useful for the study of bacterial souring and corrosion. Test kits are available to measure sulfide in field samples. A more precise methylene blue sulfide assay for both field and laboratory studies is described here. Improved media, compared to that in API RP-38, for enumeration of SRB have been formulated. One of these, API-RST, contained cysteine (1.1 mM) as a reducing agent, which may be a confounding source of sulfide. While cysteine was required for rapid enumeration of SRB from environmental samples, the concentration of cysteine in medium could be reduced to 0.4 mM. It was also determined that elevated levels of yeast extract (>1 g/liter) could interfere with enumeration of SRB from environmental samples. The API-RST medium was modified to a RST-11 medium. Other changes in medium composition, in addition to reduction of cysteine, included reduction of the concentration of phosphate from 3.4 mM to 2.2 mM, reduction of the concentration of ferrous iron from 0.8 mM to 0.5 mM and preparation of a stock mineral solution to ease medium preparation. SRB from environmental samples could be enumerated in a week in this medium.

  19. Hydrogen Sulfide in Preeclampsia : Potential Therapeutic Implications

    NARCIS (Netherlands)

    Holwerda, Kim

    2015-01-01

    The thesis provide insights into the production and possible therapeutic effect of the gaseous molecule hydrogen sulfide (H2S) in preeclampsia (PE). H2S is an important molecule in the (human) body. It is among others involved in blood pressure regulation, stimulation of vascular growth and

  20. Nucleation of mercury sulfide by dealkylation

    Science.gov (United States)

    Enescu, Mironel; Nagy, Kathryn L.; Manceau, Alain

    2016-12-01

    Metal sulfide minerals are assumed to form naturally at ambient conditions via reaction of a metallic element with (poly)sulfide ions, usually produced by microbes in oxygen-depleted environments. Recently, the formation of mercury sulfide (β-HgS) directly from linear Hg(II)-thiolate complexes (Hg(SR)2) in natural organic matter and in cysteine solutions was demonstrated under aerated conditions. Here, a detailed description of this non-sulfidic reaction is provided by computations at a high level of molecular-orbital theory. The HgS stoichiometry is obtained through the cleavage of the S-C bond in one thiolate, transfer of the resulting alkyl group (R’) to another thiolate, and subsequent elimination of a sulfur atom from the second thiolate as a thioether (RSR’). Repetition of this mechanism leads to the formation of RS-(HgS)n-R chains which may self-assemble in parallel arrays to form cinnabar (α-HgS), or more commonly, quickly condense to four-coordinate metacinnabar (β-HgS). The mechanistic pathway is thermodynamically favorable and its predicted kinetics agrees with experiment. The results provide robust theoretical support for the abiotic natural formation of nanoparticulate HgS under oxic conditions and in the absence of a catalyst, and suggest a new route for the (bio)synthesis of HgS nanoparticles with improved technological properties.

  1. 30 CFR 250.490 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... been confirmed. Well-control fluid means drilling mud and completion or workover fluid as appropriate... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Hydrogen Sulfide § 250.490 Hydrogen... section when conducting drilling, well-completion/well-workover, and production operations in zones...

  2. Microaeration reduces hydrogen sulfide in biogas

    Science.gov (United States)

    Although there are a variety of biological and chemical treatments for removal of hydrogen sulfide (H2S) from biogas, all require some level of chemical or water inputs and maintenance. In practice, managing biogas H2S remains a significant challenge for agricultural digesters where labor and opera...

  3. Microbial Fuel Cells for Sulfide Removal

    NARCIS (Netherlands)

    Rabaey, K.; Sompel, van de S.; Maignien, L.; Boon, N.; Aelterman, P.; Clauwaert, P.; Schamphelaire, de L.; The Pham, H.; Vermeulen, J.; Verhaege, M.; Lens, P.N.L.; Verstraete, W.

    2006-01-01

    Thus far, microbial fuel cells (MFCs) have been used to convert carbon-based substrates to electricity. However, sulfur compounds are ubiquitously present in organic waste and wastewater. In this study, a MFC with a hexacyanoferrate cathodic electrolyte was used to convert dissolved sulfide to eleme

  4. Acid volatile sulfide (AVS)- a comment

    NARCIS (Netherlands)

    Meysman, F.J.R.; Middelburg, J.J.

    2005-01-01

    The review by Rickard and Morse (this volume) adequately summarizes our current understanding with respect to acid-volatile sulfides (AVS). At the same time, this review addresses some of the misunderstandings with regard to measurements and dynamics of this important sedimentary sulfur pool. In

  5. Comparison of Hydrogen Sulfide Analysis Techniques

    Science.gov (United States)

    Bethea, Robert M.

    1973-01-01

    A summary and critique of common methods of hydrogen sulfide analysis is presented. Procedures described are: reflectance from silver plates and lead acetate-coated tiles, lead acetate and mercuric chloride paper tapes, sodium nitroprusside and methylene blue wet chemical methods, infrared spectrophotometry, and gas chromatography. (BL)

  6. Hydrogen Sulfide in Preeclampsia : Potential Therapeutic Implications

    NARCIS (Netherlands)

    Holwerda, Kim

    2015-01-01

    The thesis provide insights into the production and possible therapeutic effect of the gaseous molecule hydrogen sulfide (H2S) in preeclampsia (PE). H2S is an important molecule in the (human) body. It is among others involved in blood pressure regulation, stimulation of vascular growth and modulati

  7. Sulfide Precipitation in Wastewater at Short Timescales

    DEFF Research Database (Denmark)

    Kiilerich, Bruno; van de Ven, Wilbert; Nielsen, Asbjørn Haaning

    2017-01-01

    that this is not the case for sulfide precipitation by ferric iron. Instead, the reaction time was found to be on a timescale where it must be considered when performing end-of-pipe treatment. For real wastewaters at pH 7, a stoichiometric ratio around 14 mol Fe(II) (mol S(−II))−1 was obtained after 1.5 s, while the ratio......Abatement of sulfides in sewer systems using iron salts is a widely used strategy. When dosing at the end of a pumping main, the reaction kinetics of sulfide precipitation becomes important. Traditionally the reaction has been assumed to be rapid or even instantaneous. This work shows...... dropped to about 5 mol Fe(II) (mol S(−II))−1 after 30 s. Equilibrium calculations yielded a theoretic ratio of 2 mol Fe(II) (mol S(−II))−1, indicating that the process had not equilibrated within the span of the experiment. Correspondingly, the highest sulfide conversion only reached 60%. These findings...

  8. Oxidation and Precipitation of Sulfide in Sewer Networks

    DEFF Research Database (Denmark)

    Nielsen, A. H.

    were studied in both wastewater and biofilms. Particular emphasis was on the importance of iron in the sulfur cycle. Iron is typically among the dominant metals in wastewater. The experiments showed that, ferric iron (Fe(III)) that was added to anaerobic wastewater was rapidly reduced to ferrous iron...... (Fe(II)) and precipitated subsequently with dissolved sulfide as ferrous sulfide (FeS). The ferrous sulfide precipitation was relatively fast, but not immediate. Despite the very low solubility of ferrous sulfide, initially present iron did not react completely with sulfide. This observation...

  9. Investigation of Copper Ammonia Leaching from Smelter Slags: Characterization, Leaching and Kinetics

    Science.gov (United States)

    Bidari, Ehsan; Aghazadeh, Valeh

    2015-10-01

    Although ammonia leaching of copper from slags has been reported generally as a part of copper slag utilization methods, but no detailed studies have been reported in the literature. In this research, we tried to investigate the effect of different parameters on ammonia leaching of copper from copper smelting slag by identifying different copper-bearing phases and following them during leaching time. Mineralogical characterization of the smelting slag (1.7 pct Cu) was done using X-ray fluorescence, X-ray diffraction, optical microscopy, diagnostic leaching tests, and scanning electron microscopy. The characterization studies indicated that main copper-bearing species are soluble copper oxides and chalcocite along with minor amount of covellite, bornite, blister copper particles, and chalcopyrite. It was also found that only approximately 0.2 pct Cu was present in the insoluble bulk silicate phases. These results suggest that approximately 88 pct of the total copper of slag could be extracted by ammonia sulfide leaching. Leaching tests were carried out and the effects of various parameters, namely pH, ammonia concentration, temperature, presence of oxygen, stirring speed, and pulp density were examined on copper leaching. The temperature and stirring speed had the most pronounced effect on the copper leaching, whereas ammonia affected the leaching yield at low concentrations of ammonia. It was found that 78 pct of Cu could be extracted within 4 hours and under optimum conditions: T = 343 K (70 °C), 2M ammonia, pH 10.5, stirring speed = 900 rpm, pulp density = 10 pct ( w s/ v). The kinetic data were analyzed with the shrinking core models, and it was found that the leaching process is controlled by both the interfacial transfer and diffusion across the product layer and the activation energy is calculated to be 49.4 kJ mol-1.

  10. Kunpeng Copper:The largest Copper Smelting Company of Sichuan

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>On September 9,Liangshan Mining Company’s 100,000 tons/year cathode copper project kicked off.It is another key project of the company following the successful launch of the 100,000 tons/year anode copper project.Based on ISA copper smelting technology of the largest open-cast copper mine in southwest China,

  11. Sulfide removal by moderate oxygenation of anaerobic sludge environments

    Energy Technology Data Exchange (ETDEWEB)

    Van der Zee, F.P.; Villaverde, S.; Polanco, F. [Valladolid Univ., Valladolid (Spain). Dept. of Chemical Engineering; Garcia, P.A.

    2004-07-01

    Treating wastewater through anaerobic bioreactors results in the formation of hydrogen sulfide. The sulfide can be removed from the biogas by introducing air directly into the anaerobic bioreactor system. This study presents the results of batch experiments that provided a better insight into the fate of sulfur compounds and oxygen during microaerobic sulfide oxidation in granular sludge. It was shown that sulfide could be removed rapidly upon introduction of low amounts of oxygen to the sulfide-amended batch vials with granular sludge treating vinasse. Initially, the sulfide was oxidized to elemental sulfur, thiosulfate and polysulfide. Significant production of sulfate did not occur. The introduction of oxygen, however, could result in the growth of aerobic organic-chemical oxygen demand-oxidizing bacteria that compete with sulfide oxidation for oxygen. 6 refs., 1 tab., 1 fig.

  12. Occurrence and speciation of copper in slags obtained during the pyrometallurgical processing of chalcopyrite concentrates at the Huelva smelter (Spain

    Directory of Open Access Journals (Sweden)

    Fernández-Caliani J.C.

    2012-01-01

    Full Text Available Slags involved in smelting-converting-refining operations to produce blister copper at the Atlantic Copper smelter, in Huelva (Spain, have been investigated by quantitative electron microprobe analysis, X-ray diffraction and digital imaging techniques. The results showed that mechanically entrapped matte particles are the dominant copper losses in the slags. The largest proportion of Cubearing particles (2.0-3.5 vol % is present in the magnetite-rich converter slags, due to the negative effect of viscosity on coalescence and precipitation of copper matte during conversion. They consist of high-grade matte particles with a core of copper metal rimmed by a copper sulfide phase (Cu2S. The mechanical entrainment of copper matte by slags from both the flash and electric furnaces resulted in copper losses accounting for less than 1.5 vol %, mostly occurring as tiny particles with a stoichiometric composition close to that of bornite (Cu5FeS4. Copper was not found to be enriched in fayalite and magnetite as solid solution.

  13. A statistical approach to the experimental design of the sulfuric acid leaching of gold-copper ore

    Directory of Open Access Journals (Sweden)

    Mendes F.D.

    2003-01-01

    Full Text Available The high grade of copper in the Igarapé Bahia (Brazil gold-copper ore prevents the direct application of the classic cyanidation process. Copper oxides and sulfides react with cyanides in solution, causing a high consumption of leach reagent and thereby raising processing costs and decreasing recovery of gold. Studies have showm that a feasible route for this ore would be a pretreatment for copper minerals removal prior to the cyanidation stage. The goal of this experimental work was to study the experimental conditions required for copper removal from Igarapé Bahia gold-copper ore by sulfuric acid leaching by applying a statistical approach to the experimental design. By using the Plackett Burman method, it was possible to select the variables that had the largest influence on the percentage of copper extracted at the sulfuric acid leaching stage. These were temperature of leach solution, stirring speed, concentration of sulfuric acid in the leach solution and particle size of the ore. The influence of the individual effects of these variables and their interactions on the experimental response were analyzed by applying the replicated full factorial design method. Finally, the selected variables were optimized by the ascending path statistical method, which determined the best experimental conditions for leaching to achieve the highest percentage of copper extracted. Using the optimized conditions, the best leaching results showed a copper extraction of 75.5%.

  14. Posttranslational regulation of copper transporters

    NARCIS (Netherlands)

    van den Berghe, P.V.E.

    2009-01-01

    The transition metal copper is an essential cofactor for many redox-active enzymes, but excessive copper can generate toxic reactive oxygen species. Copper homeostasis is maintained by highly conserved proteins, to balance copper uptake, distribution and export on the systemic and cellular level. Th

  15. Report on exploration of the Wadi Yiba copper prospect, Tihamat Ash Sham quadrangle, Kingdom of Saudi Arabia

    Science.gov (United States)

    Earhart, Robert L.

    1969-01-01

    The first phase of an exploration program at The Wadi Yiba copper prospect consisted of geologic mapping, prospecting, sampling, geophysical surveys, and diamond drilling. Copper mineralization is in a sedimentary rock sequence comprised mostly of siliceous, calcareous, and dolomitic rocks metamorphosed to the greenschist facies. The metasedimentary rocks are overlain and underlain by metavolcanic rocks. They are folded into a tight north-plunging syncline transected by two fault systems. Results from the exploration program indicate that a fault zone which sub-parallels the synclinal axis and cuts siliceous dolomite contains copper mineralization and small amounts of gold and silver. Copper and silver beaming pyroclastic rocks were found in the upper part of the metasedimentary rock sequence. Concentrations of copper mineralization seem to be restricted to particular rock units in the metasedimentary rock sequence. Primary sulfides have not been encountered in the drill holes to date and the results from one drill hole indicate secondary copper sulfide minerals to a vertical depth of 60 meters. Further exploration seems to be warranted and a program is proposed which includes the investigation of other mineral occurrences and geophysical anomalies in the region.

  16. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  17. [Copper and the human body].

    Science.gov (United States)

    Krízek, M; Senft, V; Motán, J

    1997-11-19

    Copper is one of the essential trace elements. It is part of a number of enzymes. Deficiency of the element is manifested by impaired haematopoesis, bone metabolism, disorders of the digestive, cardiovascular and nervous system. Deficiency occurs in particular in patients suffering from malnutrition, malabsorption, great copper losses during administration of penicillamine. Sporadically copper intoxications are described (suicidal intentions or accidental ingestion of beverages with a high copper content). Acute exposure to copper containing dust is manifested by metal fume fever. Copper salts can produce local inflammations. Wilson's disease is associated with inborn impaired copper metabolism. In dialyzed patients possible contaminations of the dialyzate with copper must be foreseen as well as the possible release of copper from some dialyzation membranes. With the increasing amount of copper in the environment it is essential to monitor the contamination of the environment.

  18. 铜萃余液综合回收铜、锌试验研究%Experimental study on comprehensive recovery of copper and zinc from copper extraction raffinate

    Institute of Scientific and Technical Information of China (English)

    俎小凤; 王夏

    2013-01-01

    采用硫化沉淀工艺对铜萃余液中的铜、锌等有价金属进行了回收试验研究,考察了硫化沉淀pH值、硫化钠加入量和硫化反应时间等因素以及铜、锌共沉淀和分步沉淀对铜、锌回收率和精矿品位的影响.试验结果表明,铜、锌分步沉淀时,萃余液pH =2.5,加入1.2倍硫化钠用量,反应20 min,沉铜效果最好,铜回收率98.33%,精矿铜品位38.88%;pH =3.5,加入1.4倍硫化钠用量,反应20 min,沉锌效果最好,锌回收率为98.36%,精矿锌品位33.17%.该工艺可有效回收萃余液中的铜、锌等有价金属.%The experimental study on using sulfide precipitation process to recover copper, zinc and other valuable metals from copper extraction raffinate was carried out.The study investigated the influence on copper and zinc recovery rate and concentrate grade played by pH of sulfide precipitation,sodium sulfide dosage and curing reaction time,as well as one step precipitation and multiple-step precipitation.The results show that it achieves the best results that the copper recovery rate is 98.33 % and the concentrate grade is 38.88 % on the condition of multiple sulfide precipitation ,and that the raffinate pH is 2.5 ,1.2 times amount of sodium sulfide is added and the reaction time is 20 minutes.The best effect for zinc immersion is achieved on the condition that PH is 3.5,1.4 times amount of sodium sulfide is added and the reaction time is 20 minutes.With that, zinc recovery rate is 98.36 % and concentrate grade is 33.17 %.The process can effectively recover copper,zinc and other valuable metals from copper raffinate.

  19. Targeting copper in cancer therapy: 'Copper That Cancer'.

    Science.gov (United States)

    Denoyer, Delphine; Masaldan, Shashank; La Fontaine, Sharon; Cater, Michael A

    2015-11-01

    Copper is an essential micronutrient involved in fundamental life processes that are conserved throughout all forms of life. The ability of copper to catalyze oxidation-reduction (redox) reactions, which can inadvertently lead to the production of reactive oxygen species (ROS), necessitates the tight homeostatic regulation of copper within the body. Many cancer types exhibit increased intratumoral copper and/or altered systemic copper distribution. The realization that copper serves as a limiting factor for multiple aspects of tumor progression, including growth, angiogenesis and metastasis, has prompted the development of copper-specific chelators as therapies to inhibit these processes. Another therapeutic approach utilizes specific ionophores that deliver copper to cells to increase intracellular copper levels. The therapeutic window between normal and cancerous cells when intracellular copper is forcibly increased, is the premise for the development of copper-ionophores endowed with anticancer properties. Also under investigation is the use of copper to replace platinum in coordination complexes currently used as mainstream chemotherapies. In comparison to platinum-based drugs, these promising copper coordination complexes may be more potent anticancer agents, with reduced toxicity toward normal cells and they may potentially circumvent the chemoresistance associated with recurrent platinum treatment. In addition, cancerous cells can adapt their copper homeostatic mechanisms to acquire resistance to conventional platinum-based drugs and certain copper coordination complexes can re-sensitize cancer cells to these drugs. This review will outline the biological importance of copper and copper homeostasis in mammalian cells, followed by a discussion of our current understanding of copper dysregulation in cancer, and the recent therapeutic advances using copper coordination complexes as anticancer agents.

  20. Sulfide, the first inorganic substrate for human cells.

    Science.gov (United States)

    Goubern, Marc; Andriamihaja, Mireille; Nübel, Tobias; Blachier, François; Bouillaud, Frédéric

    2007-06-01

    Hydrogen sulfide (H2S) is produced inside the intestine and is known as a poison that inhibits cellular respiration at the level of cytochrome oxidase. However, sulfide is used as an energetic substrate by many photo- and chemoautotrophic bacteria and by animals such as the lugworm Arenicola marina. The concentrations of sulfide present in their habitats are comparable with those present in the human colon. Using permeabilized colonic cells to which sulfide was added by an infusion pump we show that the maximal respiratory rate of colonocyte mitochondria in presence of sulfide compares with that obtained with succinate or L-alpha-glycerophosphate. This oxidation is accompanied by mitochondrial energization. In contrast, other cell types not naturally exposed to high concentration of sulfide showed much lower oxidation rates. Mitochondria showed a very high affinity for sulfide that permits its use as an energetic substrate at low micromolar concentrations, hence, below the toxic level. However, if the supply of sulfide exceeds the oxidation rate, poisoning renders mitochondria inefficient and our data suggest that an anaerobic mechanism involving partial reversion of Krebs cycle already known in invertebrates takes place. In conclusion, this work provides additional and compelling evidence that sulfide is not only a toxic compound. According to our study, sulfide appears to be the first inorganic substrate for mammalian cells characterized thus far.

  1. The Evolution of Sulfide Tolerance in the Cyanobacteria

    Science.gov (United States)

    Miller, Scott R.; Bebout, Brad M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Understanding how the function of extant microorganisms has recorded both their evolutionary histories and their past interactions with the environment is a stated goal of astrobiology. We are taking a multidisciplinary approach to investigate the diversification of sulfide tolerance mechanisms in the cyanobacteria, which vary both in their degree of exposure to sulfide and in their capacity to tolerate this inhibitor of photosynthetic electron transport. Since conditions were very reducing during the first part of Earth's history and detrital sulfides have been found in Archean sediments, mechanisms conferring sulfide tolerance may have been important for the evolutionary success of the ancestors of extant cyanobacteria. Two tolerance mechanisms have been identified in this group: (1) resistance of photosystem II, the principal target of sulfide toxicity; and (2) maintenance of the ability to fix carbon despite photosystem II inhibition by utilizing sulfide as an electron donor in photosystem I - dependent, anoxygenic photosynthesis. We are presently collecting comparative data on aspects of sulfide physiology for laboratory clones isolated from a variety of habitats. These data will be analyzed within a phylogenetic framework inferred from molecular sequence data collected for these clones to test how frequently different mechanisms of tolerance have evolved and which tolerance mechanism evolved first. In addition, by analyzing these physiological data together with environmental sulfide data collected from our research sites using microelectrodes, we can also test whether the breadth of an organism's sulfide tolerance can be predicted from the magnitude of variation in environmental sulfide concentration it has experienced in its recent evolutionary past and whether greater average sulfide concentration and/or temporal variability in sulfide favors the evolution of a particular mechanism of sulfide tolerance.

  2. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, December 1, 1993--February 28, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Hill, A.H. [Institute of Gas Technology, Chicago, IL (United States); Flytzani-Stephanopoulos, M.; Li, Zhijiang [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1994-06-01

    The objective of this investigation is to evaluate two novel copper-based sorbents, namely copper-chromium and copper-cerium, for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650{degree} to 850{degree}. Such high temperatures will be required for the new generation of gas turbines (inlet >750{degree}C) in Integrated Gasification Combined Cycle (IGCC) systems. The effect of pre-reduction with H{sub 2}, in the presence of H{sub 2}O on the performance of the sorbents in cyclic sulfidation/regeneration, was studied in a thermogravimetric analyzer (TGA) and in a fixed-bed reactor at 750{degree}C. The results of the TGA tests indicate that pre-reduction of the sorbents is very fast in either 10% or 30% H{sub 2}. Without sorbent pre-reduction, sulfidation consists of two-stages, a reduction-dominating and a sulfidation-dominating stage. Sulfidation apparently takes place before reduction is complete. During regeneration some copper/cerium sulfates may have formed and Cu{sub 2}O may have formed in addition to CuO. The fixed-bed reactor tests show that at 750{degree}C: (1) prereducing the CuO-Cr{sub 2}O{sub 3} with H{sub 2} does not effect the reactivity of the sorbent towards H{sub 2}S at either the high or low H{sub 2} feed gas concentrations and (2) when 30% H{sub 2} was used during sulfidation of either sorbent, the first H{sub 2}S breakthrough occurs earlier than when 10% H{sub 2} was used.

  3. Mineralogy and Geochemical Processes of Carbonate Mineral-rich Sulfide Mine Tailings, Zimapan, Mexico

    Science.gov (United States)

    McClure, R. J.; Deng, Y.; Loeppert, R.; Herbert, B. E.; Carrillo, R.; Gonzalez, C.

    2009-12-01

    Mining for silver, lead, zinc, and copper in Zimapan, Hidalgo State, Mexico has been ongoing since 1576. High concentrations of heavy metals have been found in several mine tailing heaps in the Zimapan area, with concentrations of arsenic observed as high as 28,690 mg/kg and levels of Pb as high as 2772 mg/kg. Unsecured tailings heaps and associated acid mine drainage has presented tremendous problems to revegetation, water quality, and dust emission control in the Zimapan area. Although acid mine drainage problems related to weathering of sulfide minerals have been extensively studied and are well known, the weathering products of sulfides in areas with a significant presence of carbonate minerals and their effect on the mobility of heavy metals warrant further study. Carbonate minerals are expected to neutralize sulfuric acid produced from weathering of sulfide minerals, however, in the Zimapan area localized areas of pH as low as 1.8 were observed within carbonate mineral-rich tailing heaps. The objectives of this study are to characterize (1) the heavy metal-containing sulfide minerals in the initial tailing materials, (2) the intermediate oxidation products of sulfide minerals within the carbonate-rich tailings, (3) chemical species of heavy metals within pH gradients between 1.8 and 8.2, the approximate natural pH of limestone, and (4) the mobility of soluble and colloidal heavy metals and arsenic within the carbonate-rich tailings. Representative mine tailings and their intermediate oxidation products have been sampled from the Zimapan area. Mineralogical characterization will be conducted with X-ray diffraction, infrared spectroscopy, electron microscopes and microprobes, and chemical methods. Chemical species will be extracted by selective dissolution methods. Preliminary results have identified calcite as the dominant mineral in the tailing heaps with a pH of 7, suggesting non-equilibrium with the acidic weathering products. Other minerals identified in

  4. Iron-sulfide redox flow batteries

    Science.gov (United States)

    Xia, Guan-Guang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2013-12-17

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  5. Oxidation of Reduced Sulfur Species: Carbonyl Sulfide

    DEFF Research Database (Denmark)

    Glarborg, Peter; Marshall, Paul

    2013-01-01

    A detailed chemical kinetic model for oxidation of carbonyl sulfide (OCS) has been developed, based on a critical evaluation of data from the literature. The mechanism has been validated against experimental results from batch reactors, flow reactors, and shock tubes. The model predicts satisfact......A detailed chemical kinetic model for oxidation of carbonyl sulfide (OCS) has been developed, based on a critical evaluation of data from the literature. The mechanism has been validated against experimental results from batch reactors, flow reactors, and shock tubes. The model predicts...... by the competition between chain‐branching and ‐propagating steps; modeling predictions are particularly sensitive to the branching fraction for the OCS + O reaction to form CO + SO or CO2 + S....

  6. Speciation of arsenic in sulfidic waters

    Directory of Open Access Journals (Sweden)

    Ford Robert G

    2003-03-01

    Full Text Available Formation constants for thioarsenite species have been determined in dilute solutions at 25°C, ΣH2S from 10-7.5 to 10-3.0 M, ΣAs from 10-5.6 to 10-4.8 M, and pH 7 and 10. The principal inorganic arsenic species in anoxic aquatic systems are arsenite, As(OH30, and a mononuclear thioarsenite with an S/As ratio of 3:1. Thioarsenic species with S/As ratios of 1 : 1,2 : 1, and 4 : 1 are lesser components in sulfidic solutions that might be encountered in natural aquatic environments. Thioarsenites dominate arsenic speciation at sulfide concentrations > 10-4.3 M at neutral pH. Conversion from neutral As(OH30 to anionic thioarsenite species may regulate the transport and fate of arsenic in sulfate-reducing environments by governing sorption and mineral precipitation reactions.

  7. Iron-sulfide redox flow batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Guanguang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2016-06-14

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  8. Subsurface heaters with low sulfidation rates

    Energy Technology Data Exchange (ETDEWEB)

    John, Randy Carl; Vinegar, Harold J

    2013-12-10

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  9. Hydrogen sulfide prodrugs—a review

    Directory of Open Access Journals (Sweden)

    Yueqin Zheng

    2015-09-01

    Full Text Available Hydrogen sulfide (H2S is recognized as one of three gasotransmitters together with nitric oxide (NO and carbon monoxide (CO. As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications.

  10. Hydrogen sulfide prodrugs—a review

    Science.gov (United States)

    Zheng, Yueqin; Ji, Xingyue; Ji, Kaili; Wang, Binghe

    2015-01-01

    Hydrogen sulfide (H2S) is recognized as one of three gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications. PMID:26579468

  11. LEP copper accelerating cavities

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    These copper cavities were used to generate the radio frequency electric field that was used to accelerate electrons and positrons around the 27-km Large Electron-Positron (LEP) collider at CERN, which ran from 1989 to 2000. The copper cavities were gradually replaced from 1996 with new superconducting cavities allowing the collision energy to rise from 90 GeV to 200 GeV by mid-1999.

  12. Redetermination of piperidinium hydrogen sulfide structure

    Science.gov (United States)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    The presence of adventitious water in a reaction between dicyclopentamethylene thiuram-disulfide (C5H10NCS2)(sub 2) and a picoline solution of tricyclopentadienyl indium(III) (C5H5)(sub 3). It resulted in the formation of piperidinium hydrogen sulfide (C5H13NS). The piperidinium hydrogen sulfide produced in this way was unambiguously characterized by X-ray crystallography. The structure determination showed that the piperidinium hydrogen sulfide crystal (MW = 119.23 g/mol) has an orthorhombic (Pbcm) unit cell whose parameters are: a = 9.818(2), b = 7.3720(1), c = 9.754(1) A, V = 706.0(3) A(exp 3), Z=4. D(sub chi) = 1.122 g cm(exp -3), Mo K(alpha) (lamda = 0.71073), mu= 3.36 cm(exp -1), F(000) = 264.0, T =293 K, R = 0.036 for 343 reflections with F(sub O)(sup 2) greater than 3 sigma (F(sub O)(sup 2)) and 65 variables. The compound consists of (C5H10NH2)(+) cations and (SH)(-) anions with both species residing on crystallographic mirror planes. N-H -- S hydrogen bonding contributes to the interconnection of neighboring piperidinium components of the compound.

  13. Air-water transfer of hydrogen sulfide

    DEFF Research Database (Denmark)

    Yongsiri, C.; Vollertsen, J.; Rasmussen, M. R.

    2004-01-01

    experiments. By means of the overall mass–transfer coefficient (KLa), the transfer coefficient of hydrogen sulfide (KLaH2S), referring to total sulfide, was correlated to that of oxygen (KLaO2) (i.e., the reaeration coefficient). Results demonstrate that both turbulence and pH in the water phase play...... a significant role for KLaH2S. An exponential expression is a suitable representation for the relationship between KLaH2S and the Froude number at all pH values studied (4.5 to 8.0). Because of the dissociation of hydrogen sulfide, KLaH2S increased with decreasing pH at a constant turbulence level. Relative...... differences in KLaH2S at pH values between 4.5 and 8.0 became larger as the turbulence level increased, whereas those at pH between 4.5 and 7.0 did not statistically show any change. At constant pH, KLaH2S/KLaO2 was observed not to be dependent on the turbulence range studied. KLaH2S/KLaO2 ratio was 0...

  14. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  15. Magmatic Sulfide Ni-Cu Deposits in China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Deep-seated magmatic liquation-injection deposits form a major type of magmatic sulfide deposit in China. The reserves of nickel and copper in this type of deposit may attain several hundred thousand tons (e.g.Hongqi 7 and Karatunggu) to nearly ten million tons (e.g.Jinchuan). Those deposits can be classified as large or superlarge deposits. The ore grade is relatively high, commonly with w(Ni)>1 %.The mineralized intrusions are small in size, generally only 0.0n km2 to 0.n km2, with the largest one not exceeding a few km2. Before intruding, the primary magmas have undergone liquation and partial crystallization at depth; as a result, the magmas have partitioned into barren magma, ore-bearing magma, ore-rich magma and ore magma, which then ascended and injected into the present locations once or multiple times, to form ore deposits. The above-mentioned mineralizing process is known as deep-seated magmatic liquation-injection mineralization. The volume of the barren magma is generally much larger than those of the ore-bearing magma, ore-rich magma and ore magma. In the ascending process, most of the barren magma intruded into different locations or outpoured onto the ground surface, forming intrusions or lava flows. The rest barren magma, ore-bearing magma, ore-rich magmaand ore magma may either multiple times inject into the same place in which rocks and ores are formed or separately inject into different spaces to form rocks and ores. Such deep-seated magmatic liquation-injection deposits have a much smaller volume, greater ore potential and higher ore grade than those of in-situ magmatic liquation deposits. Consequently, this mineralizing process leads to the formation of large deposits in small intrusions.

  16. Copper Recovery from Yimen Copper Smelting Slag%易门铜冶炼渣选铜试验

    Institute of Scientific and Technical Information of China (English)

    谢贤; 杨子轩; 童雄; 侯凯; 黎继永

    2015-01-01

    The composition of Yimen copper smelting slag was complex,with Cu grade of 1. 83%. Main copper minerals are copper sulfide,accounting for 94. 54% of total copper. In order to high efficiently recover copper,mineral processing tests were carried out. The results showed that,at the grinding fineness of the-0. 045 mm accounted for 90%,through the process of one roughing-three cleaning-two scavenging,copper concentrate with copper grade of 18. 27% and recovery of 84. 86%,and silver grade of 76. 20 g/t and recovery of 44. 06% was obtained separately. The beneficiation process selected is simple,which can better recover the copper,and comprehensively recover the silver. It is the ideal process for copper recovery from the sam-ple.%易门铜冶炼渣成分复杂,铜品位为1.83%,主要铜矿物为硫化铜,占总铜的94.54%。为高效回收其中的铜,进行了选矿试验研究。结果表明,在磨矿细度为-0.045 mm占90%的情况下,采用1粗3精2扫、中矿顺序返回浮选流程处理该试样,可获得铜品位为18.27%、含银76.20g/t、铜回收率为84.86%、银回收率为44.06%的铜精矿。试验确定的选矿工艺流程较简单,不仅对铜有较好的回收效果,而且综合回收了其中的银,是该试样中铜的理想回收工艺。

  17. The effect of iron and copper impurities on the wettability of sphalerite (110) surface.

    Science.gov (United States)

    Simpson, Darren J; Bredow, Thomas; Chandra, Anand P; Cavallaro, Giuseppe P; Gerson, Andrea R

    2011-07-15

    The effect of impurities in the zinc sulfide mineral sphalerite on surface wettability has been investigated theoretically to shed light on previously reported conflicting results on sphalerite flotation. The effect of iron and copper impurities on the sphalerite (110) surface energy and on the water adsorption energy was calculated with the semi-empirical method modified symmetrically orthogonalized intermediate neglect of differential overlap (MSINDO) using the cyclic cluster model. The effect of impurities or dopants on surface energies is small but significant. The surface energy increases with increasing surface iron concentration while the opposite effect is reported for increasing copper concentration. The effect on adsorption energies is much more pronounced with water clearly preferring to adsorb on an iron site followed by a zinc site, and copper site least favorable. The theoretical results indicate that a sphalerite (110) surface containing iron is more hydrophilic than the undoped zinc sulfide surface. In agreement with the literature, the surface containing copper (either naturally or by activation) is more hydrophobic than the undoped surface. Copyright © 2011 Wiley Periodicals, Inc.

  18. Fundamental aspects of stress corrosion cracking of copper relevant to the Swedish deep geologic repository concept

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskaran, Ganesh; Carcea, Anatolie; Ulaganathan, Jagan; Wang, Shengchun; Huang, Yin; Newman, Roger C. [Dept. of Chemical Engineering and Applied Chemistry, Univ. of Toronto, Toronto (Canada)

    2013-03-15

    Phosphorus-doped oxygen-free copper will be used as the outer barrier in canisters that will contain spent nuclear fuel in the proposed Swedish underground repository. The possibility of stress corrosion cracking (SCC) is a concern, in view of isolated reports of cracking or intergranular corrosion of pure copper in sulfide solutions. This concern was addressed in the present work using copper tensile specimens provided by SKB. Methods included slow strain rate testing, constant strain tensile testing, electrochemical and surface analytical studies of corrosion products, and electron backscatter diffraction analysis of grain orientation effects on corrosion. The base solutions were prepared from NaCl or synthetic sea water with addition of varying amounts of sodium sulfide at room temperature and 80 degree Celsius. No SCC was found in any of the testing, for a range of sulfide concentrations from 5-50 mM at room temperature or 8 C, including tests where small anodic or cathodic potential displacements were applied from the open-circuit (corrosion) potential. Neither was SCC found in constant-strain immersion testing with very large strain. The Cu2S corrosion product is generally very coarse, fragile, and easily spalled off in severe corrosion environments, i.e. high sulfide concentration, high temperature, less perfect de aeration, etc. But it could also consist of very fine grains, relatively compact and adherent, on particular grain orientations when it was formed on an electro polished surface in a very well-deaerated solution. These orientations have not yet been identified statistically, although some preference for thin, adherent films was noted on orientations close to (100). The notion that the corrosion reaction is always controlled by inward aqueous-phase diffusion of sulfide may thus not be unconditionally correct for this range of sulfide concentrations; however it is hard to distinguish the role of diffusion within pores in the film. In the actual

  19. Organization of the human mitochondrial hydrogen sulfide oxidation pathway.

    Science.gov (United States)

    Libiad, Marouane; Yadav, Pramod Kumar; Vitvitsky, Victor; Martinov, Michael; Banerjee, Ruma

    2014-11-07

    Sulfide oxidation is expected to play an important role in cellular switching between low steady-state intracellular hydrogen sulfide levels and the higher concentrations where the physiological effects are elicited. Yet despite its significance, fundamental questions regarding how the sulfide oxidation pathway is wired remain unanswered, and competing proposals exist that diverge at the very first step catalyzed by sulfide quinone oxidoreductase (SQR). We demonstrate that, in addition to sulfite, glutathione functions as a persulfide acceptor for human SQR and that rhodanese preferentially synthesizes rather than utilizes thiosulfate. The kinetic behavior of these enzymes provides compelling evidence for the flow of sulfide via SQR to glutathione persulfide, which is then partitioned to thiosulfate or sulfite. Kinetic simulations at physiologically relevant metabolite concentrations provide additional support for the organizational logic of the sulfide oxidation pathway in which glutathione persulfide is the first intermediate formed.

  20. Sulfide scaling in low enthalpy geothermal environments; A survey

    Energy Technology Data Exchange (ETDEWEB)

    Criaud, A.; Fouillac, C. (Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France))

    1989-01-01

    A review of the sulfide scaling phenomena in low-temperature environments is presented. While high-temperature fluids tend to deposit metal sulfides because of their high concentrations of dissolved metals and variations of temperature, pressure and fluid chemistry, low temperature media are characterized by very low metal content but much higher dissolved sulfide. In the case of the goethermal wells of the Paris Basin, detailed studies demonstrate that the relatively large concentrations of chloride and dissolved sulfide are responsible for corrosion and consequent formation of iron sulfide scale composed of mackinawite, pyrite and pyrrhotite. The effects of the exploitation schemes are far less important than the corrosion of the casings. The low-enthalpy fluids that do not originate from sedimentary aquifers (such as in Iceland and Bulgaria), have a limited corrosion potential, and the thin sulfide film that appears may prevent the progress of corrosion.

  1. Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

  2. Measurement of plasma hydrogen sulfide in vivo and in vitro

    OpenAIRE

    Shen, Xinggui; Pattillo, Christopher B.; Pardue, Sibile; Bir, Shyamal C.; Wang, Rui; Kevil, Christopher G.

    2011-01-01

    The gasotransmitter hydrogen sulfide is known to regulate multiple cellular functions during normal and pathophysiological states. However, a paucity of concise information exists regarding quantitative amounts of hydrogen sulfide involved in physiological and pathological responses. This is primarily due to disagreement among various methods employed to measure free hydrogen sulfide. In this article, we describe a very sensitive method of measuring the presence of H2S in plasma down to nanom...

  3. Surface and capillary forces encountered by zinc sulfide microspheres in aqueous electrolyte.

    Science.gov (United States)

    Gillies, Graeme; Kappl, Michael; Butt, Hans-Jürgen

    2005-06-21

    The colloid probe technique was used to investigate the interactions between individual zinc sulfide (ZnS) microspheres and an air bubble in electrolyte solution. Incorporation of zinc ions into the electrolyte solution overcomes the disproportionate zinc ion dissolution and mimics high-volume-fraction conditions common in flotation. Determined interaction forces revealed a distinct lack of long-ranged hydrophobic forces, indicated by the presence of a DLVO repulsion prior to particle engulfment. Single microsphere contact angles were determined from particle-bubble interactions. Contact angles increased with decreasing radii and with surface oxidation. Surface modification by the absorption of copper and subsequently potassium O-ethyldithiocarbonate (KED) reduced repulsive forces and strongly increased contact angles.

  4. 铜尾矿中铜矿物综合回收影响因素分析%Influence factors analysis of separation recycling of copper minerals in copper tailings

    Institute of Scientific and Technical Information of China (English)

    宋磊; 周少珍

    2014-01-01

    铜尾矿是较为典型的有色金属尾矿,影响铜尾矿中铜矿物综合回收的主要因素有:、铜赋存状态复杂、铜嵌布粒度细、铜解理度低、含泥量大。针对铜尾矿的特点,采用预先分级处理、铜矿物表面处理、先硫后氧不脱泥分步硫化浮选等针对性工艺措施,可以有效回收铜尾矿中铜矿物。%Copper tailings is a typical nonferrous metal tailings ,the main influence factors of comprehensive recovery of copper in copper tailings are :complex copperoccurrence states ,fineparticlesizeof copper ,low liberation degree of copper ,high mud content in the tailings .According to the characteristics of the copper tailings ,take targeted measures ,such as ,preliminary classification processing ,surface treatment , sulphidecopper mineral before oxide mineralsand non-desliming sulfide flotation technology ,can effectively recover copper minerals in copper tailings .

  5. Re-Os Dating of the Pulang Porphyry Copper Deposit in Zhongdian, NW Yunnan, and Its Geological Significance

    Institute of Scientific and Technical Information of China (English)

    ZENG Pusheng; HOU Zengqian; WANG Haiping; QU Wenjun; MENG Yifeng; YANG Zhusen; LI Wenchang

    2004-01-01

    The Pulang porphyry copper deposit is located in the Zhongdian island arc belt, NW Yunnan, in the central part of the Sanjiang area, SW China, belonging to the southern segment of the Yidun island arc belt on the western margin of the Yangtze Platform. In the Yidun island arc, there occur well-known "Gacun-style" massive sulfide deposits in the northern segment and plenty of porphyry copper deposits in the southern segment, of which the Pulang porphyry copper deposit is one of the representatives. Like the Yulong porphyry copper deposit, this porphyry copper deposit is also one of the most important porphyry copper deposits in the eastern Qinghai-Tibet Plateau. But it is different from other porphyry copper deposits in the eastern Qinghai-Tibet Plateau (e.g. those in the Gangdise porphyry copper belt and Yulong porphyry copper belt) in that it formed in the Indosinian period, while others in the Himalayan period. Because of its particularity among the porphyry copper deposits of China, this porphyry copper deposit is of great significance for the study of the basic geology and the evaluation and prediction of mineral resources in the Zhongdian island arc belt.However, no accurate chronological data are available for determining the timing of mineralization of the porphyry copper deposit. By field observation in the study area and Re-Os dating of molybdenite and K-Ar dating of hydrothermal minerals and whole rock from the typical geological bodies, the timing of mineralization of the porphyry copper deposit has systematically been determined for the first time. The K-Ar age for the hydrothermal mineralization of biotite-quartz monzonitic porphyry that has undergone patassic silicate (biotite and K-feldspar) alteration ranges from 235.4±2.4 to 221.5±2.0 Ma and the Re-Os age for molybdenite in the quartz-molybdenite stage is ~213±3.8 Ma. These data are very close to each other, suggesting that the ore-forming processes of the Pulang porphyry copper deposit was

  6. Limitation of Sulfide Capacity Concept for Molten Slags

    Science.gov (United States)

    Jung, In-Ho; Moosavi-Khoonsari, Elmira

    2016-04-01

    The sulfide capacity concept has been widely used in pyrometallurgy to define sulfur removal capacities of slags. Typically, the sulfide capacity is considered to be a unique slag property depending only on temperature regardless of partial pressures of oxygen and sulfur. In the present study, it is demonstrated that sulfide capacities of slags in particular those of Na2O-containing slags can vary with partial pressures of oxygen and sulfur due to large solubility of sulfide in Na2O-containing slag systems.

  7. Hydrogen sulfide inhibits the renal fibrosis of obstructive nephropathy.

    Science.gov (United States)

    Song, Kai; Wang, Fen; Li, Qian; Shi, Yong-Bing; Zheng, Hui-Fen; Peng, Hanjing; Shen, Hua-Ying; Liu, Chun-Feng; Hu, Li-Fang

    2014-06-01

    Hydrogen sulfide has recently been found decreased in chronic kidney disease. Here we determined the effect and underlying mechanisms of hydrogen sulfide on a rat model of unilateral ureteral obstruction. Compared with normal rats, obstructive injury decreased the plasma hydrogen sulfide level. Cystathionine-β-synthase, a hydrogen sulfide-producing enzyme, was dramatically reduced in the ureteral obstructed kidney, but another enzyme cystathionine-γ-lyase was increased. A hydrogen sulfide donor (sodium hydrogen sulfide) inhibited renal fibrosis by attenuating the production of collagen, extracellular matrix, and the expression of α-smooth muscle actin. Meanwhile, the infiltration of macrophages and the expression of inflammatory cytokines including interleukin-1β, tumor necrosis factor-α, and monocyte chemoattractant protein-1 in the kidney were also decreased. In cultured kidney fibroblasts, a hydrogen sulfide donor inhibited the cell proliferation by reducing DNA synthesis and downregulating the expressions of proliferation-related proteins including proliferating cell nuclear antigen and c-Myc. Further, the hydrogen sulfide donor blocked the differentiation of quiescent renal fibroblasts to myofibroblasts by inhibiting the transforming growth factor-β1-Smad and mitogen-activated protein kinase signaling pathways. Thus, low doses of hydrogen sulfide or its releasing compounds may have therapeutic potentials in treating chronic kidney disease.

  8. Influence of iron on sulfide inhibition in dark biohydrogen fermentation.

    Science.gov (United States)

    Dhar, Bipro Ranjan; Elbeshbishy, Elsayed; Nakhla, George

    2012-12-01

    Sulfide impact on biohydrogen production using dark fermentation of glucose at 37 °C was investigated. Dissolved sulfide (S(2-)) at a low concentration (25mg/L) increased biohydrogen production by 54% relative to the control (without iron addition). Whereas on initial dissolved S(2-) concentration of 500 mg/L significantly inhibited the biohydrogen production with total cumulative biohydrogen decreasing by 90% compared to the control (without iron addition). At sulfide concentrations of 500 mg S(2-)/L, addition of Fe(2+) at 3-4 times the theoretical requirement to precipitate 100% of the dissolved S(2-) entirely eliminated the inhibitory effect of sulfide.

  9. Discovery and Characterization of Iron Sulfide and Polyphosphate Bodies Coexisting in Archaeoglobus fulgidus Cells

    Directory of Open Access Journals (Sweden)

    Daniel B. Toso

    2016-01-01

    Full Text Available Inorganic storage granules have long been recognized in bacterial and eukaryotic cells but were only recently identified in archaeal cells. Here, we report the cellular organization and chemical compositions of storage granules in the Euryarchaeon, Archaeoglobus fulgidus strain VC16, a hyperthermophilic, anaerobic, and sulfate-reducing microorganism. Dense granules were apparent in A. fulgidus cells imaged by cryo electron microscopy (cryoEM but not so by negative stain electron microscopy. Cryo electron tomography (cryoET revealed that each cell contains one to several dense granules located near the cell membrane. Energy dispersive X-ray (EDX spectroscopy and scanning transmission electron microscopy (STEM show that, surprisingly, each cell contains not just one but often two types of granules with different elemental compositions. One type, named iron sulfide body (ISB, is composed mainly of the elements iron and sulfur plus copper; and the other one, called polyphosphate body (PPB, is composed of phosphorus and oxygen plus magnesium, calcium, and aluminum. PPBs are likely used for energy storage and/or metal sequestration/detoxification. ISBs could result from the reduction of sulfate to sulfide via anaerobic energy harvesting pathways and may be associated with energy and/or metal storage or detoxification. The exceptional ability of these archaeal cells to sequester different elements may have novel bioengineering applications.

  10. Discovery and Characterization of Iron Sulfide and Polyphosphate Bodies Coexisting in Archaeoglobus fulgidus Cells.

    Science.gov (United States)

    Toso, Daniel B; Javed, Muhammad Mohsin; Czornyj, Elizabeth; Gunsalus, Robert P; Zhou, Z Hong

    2016-01-01

    Inorganic storage granules have long been recognized in bacterial and eukaryotic cells but were only recently identified in archaeal cells. Here, we report the cellular organization and chemical compositions of storage granules in the Euryarchaeon, Archaeoglobus fulgidus strain VC16, a hyperthermophilic, anaerobic, and sulfate-reducing microorganism. Dense granules were apparent in A. fulgidus cells imaged by cryo electron microscopy (cryoEM) but not so by negative stain electron microscopy. Cryo electron tomography (cryoET) revealed that each cell contains one to several dense granules located near the cell membrane. Energy dispersive X-ray (EDX) spectroscopy and scanning transmission electron microscopy (STEM) show that, surprisingly, each cell contains not just one but often two types of granules with different elemental compositions. One type, named iron sulfide body (ISB), is composed mainly of the elements iron and sulfur plus copper; and the other one, called polyphosphate body (PPB), is composed of phosphorus and oxygen plus magnesium, calcium, and aluminum. PPBs are likely used for energy storage and/or metal sequestration/detoxification. ISBs could result from the reduction of sulfate to sulfide via anaerobic energy harvesting pathways and may be associated with energy and/or metal storage or detoxification. The exceptional ability of these archaeal cells to sequester different elements may have novel bioengineering applications.

  11. MEASURING METAL SULFIDE COMPLEXES IN OXIC RIVER WATERS WITH SQUARE WAVE VOLTAMMETRY. (R825395)

    Science.gov (United States)

    A sulfide identification protocol was developed to quantify specific metal sulfides that could exist in river water. Using a series of acid additions, nitrogen purges, and voltammetric analyses, metal sulfides were identified and semiquantified in three specific gr...

  12. Copper and Copper Proteins in Parkinson’s Disease

    OpenAIRE

    Sergio Montes; Susana Rivera-Mancia; Araceli Diaz-Ruiz; Luis Tristan-Lopez; Camilo Rios

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased pr...

  13. The use of ERTS-1 images in the search for large sulfide deposits in the Chagai District, Pakistan

    Science.gov (United States)

    Schmidt, R. G. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Visual examination of color composites was tested under relatively ideal conditions for direct detection of large hydrothermal sulfide deposits at the low-grade porphyry copper deposit at Saindak, western Chagai District, Pakistan. The Saindak deposit is characterized by an elongate zone of easily eroded sulfide-rich rock surrounded by a resistant rim of hornfels and propylitically altered rock. The geomorphic features related to the Saindak deposit are easily distinguished on ERTS-1 images. Attempts to detect a color anomaly using false-color composites were not successful. About 36,000 square km of the western Chagai District were examined on false-color composites for direct evidence of large sulfide deposits. New geologic information acquired from the images was used in conjunction with the known geology to evaluate two previously known proposed areas and to suggest seven additional targets for field checking, one of which is proposed on the basis of tonal anomaly alone. The study also showed that Saindak-type deposits are not likely to be present in some extensive areas of the Chagai District; and also that a rim like that at Saindak does not form if regional metamorphism has increased the resistance of the country rock to erosion.

  14. Toxicological analysis of 17 autopsy cases of hydrogen sulfide poisoning resulting from the inhalation of intentionally generated hydrogen sulfide gas.

    Science.gov (United States)

    Maebashi, Kyoko; Iwadate, Kimiharu; Sakai, Kentaro; Takatsu, Akihiro; Fukui, Kenji; Aoyagi, Miwako; Ochiai, Eriko; Nagai, Tomonori

    2011-04-15

    Although many cases of fatal hydrogen sulfide poisoning have been reported, in most of these cases, it resulted from the accidental inhalation of hydrogen sulfide gas. In recent years, we experienced 17 autopsy cases of fatal hydrogen sulfide poisoning due to the inhalation of intentionally generated hydrogen sulfide gas. In this study, the concentrations of sulfide and thiosulfate in blood, urine, cerebrospinal fluid and pleural effusion were examined using GC/MS. The sulfide concentrations were blood: 0.11-31.84, urine: 0.01-1.28, cerebrospinal fluid: 0.02-1.59 and pleural effusion: 2.00-8.59 (μg/ml), while the thiosulfate concentrations were blood: 0-0.648, urine: 0-2.669, cerebrospinal fluid: 0.004-0.314 and pleural effusion: 0.019-0.140 (μmol/ml). In previous reports, the blood concentration of thiosulfate was said to be higher than that of sulfide in hydrogen sulfide poisoning cases, although the latter was higher than the former in 8 of the 14 cases examined in this study. These results are believed to be strongly influenced by the atmospheric concentration of hydrogen sulfide the victims were exposed to and the time interval between exposure and death.

  15. Cupriavidus necator H16 uses flavocytochrome c-sulfide dehydrogenase to oxidize self-produced and spiked sulfide.

    Science.gov (United States)

    Lü, Chuanjuan; Xia, Yongzhen; Liu, Daixi; Zhao, Rui; Gao, Rui; Liu, Honglei; Xun, Luying

    2017-09-01

    Heterotrophic bacteria producing sulfide (H2S, HS(-), and S(2-)) during aerobic growth is a common phenomenon. Some with sulfide:quinone oxidoreductase (SQR) and persulfide dioxygenase (PDO) can oxidize self-produced sulfide to sulfite and thiosulfate, but others without these enzymes will release sulfide into the medium, from which H2S can volatilize into the gas phase. Here, we report Cupriavidus necator H16 with the fccAB genes, encoding flavocytochrome c-sulfide dehydrogenases (FCSDs), also oxidized self-produced H2S. The mutant with fccAB being deleted accumulated and released H2S. When fccAB were expressed in a 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 GSH to produce 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 taxonomic levels. 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

  16. Evidence supporting biologically mediated sulfide oxidation in hot spring ecosystems

    Science.gov (United States)

    Cox, A. D.; Shock, E.

    2011-12-01

    The sulfide concentration of fluids in hydrothermal ecosystems is one of several factors determining the transition to microbial photosynthesis (Cox et al., 2011, Chem. Geol. 280, 344-351). To investigate the loss of sulfide in Yellowstone hot spring systems, measurements of total dissolved sulfide with respect to time were made in incubation experiments conducted on 0.2-micron filtered (killed controls) vs. unfiltered hot spring water at locations with three different pH:sulfide combinations (pH 2.5 with 50 μM sulfide, 5.2 with 5.6 μM sulfide, and 8.3 with 86 μM sulfide). At the higher pH values, the experiments yielded similar rates of sulfide loss in filtered and unfiltered water of approximately 0.8 (pH 5.2) and 7.6 nmol sulfide L-1s-1 (pH 8.3). At the acidic spring, the unfiltered water lost sulfide at a rate 1.6 times that of the filtered water (8.2 vs. 5 nmol sulfide L-1s-1). These results suggest that the pelagic biomass at the pH 5.2 and 8.3 springs may not affect sulfide loss, whereas in the pH 2.5 spring there appears to be an effect. In addition, the incubation of filamentous biomass with unfiltered water increased the rate of sulfide loss by approximately two-fold at a pH of 2.5 (59 vs. 31 nmol L-1s-1; Cox et al., 2011), five-fold at a pH of 5.2 (3.9 vs. 0.8 nmol sulfide L-1s-1), and barely increased the rate of sulfide loss at a pH of 8.3 (9.1 vs. 8.4 nmol sulfide L-1s-1). Sulfide is predominately present as HS- at a pH of 8.3, which may not be taken up as easily by microorganisms as the H2S (aq) that dominates sulfide speciation at pH 2.5 and 5.2. That the loss of sulfide at acidic pH is due to biotic rather than abiotic factors is further supported by studies with whole mat samples that show greater sulfide consumption than killed controls (D'Imperio et al., 2008, AEM 74, 5802-5808). Taken together, the results of these experiments suggest that the majority of sulfide oxidation occurs in the filamentous biomass of hot spring ecosystems, although

  17. The development of 6.7% efficient copper zinc indium selenide devices from copper zinc indium sulfide nanocrystal inks

    Science.gov (United States)

    Graeser, Brian K.

    As solar cell absorber materials, alloys of CuIn(S,Se)2 and Zn(S,Se) provide an opportunity to reduce the usage of indium along with the ability to tune the band gap. Here we report successful synthesis of alloyed (CuInS2)0.5(ZnS)0.5 nanocrystals by a method that solely uses oleylamine as the liquid medium for synthesis. The reactive sintering of a thin film of these nanocrystals via selenization at 500 °C results in a uniform composition alloy (CuIn(S,Se)2)0.5(Zn(S,Se)) 0.5 layer with micron size grains. Due to the large amount of zinc in the film, the sintered grains exhibit the zinc blende structure instead of the usual chalcopyrite structure of CuIn(S,Se)2 films. The use of the selenide films as a p-type absorber layer has yielded solar cells with total area power conversion efficiencies as high as 6.7% (7.4% based on active area). These preliminary results are encouraging and indicate that with further optimization this class of materials has promise as the absorber layer in solar cells.

  18. THE DEVELOPMENT OF 6.7% EFFICIENT COPPER ZINC INDIUM SELENIDE DEVICES FROM COPPER ZINC INDIUM SULFIDE NANOCRYSTAL INKS

    OpenAIRE

    Graeser, Brian Kemp

    2014-01-01

    As solar cell absorber materials, alloys of CuIn(S,Se)2 and Zn(S,Se) provide an opportunity to reduce the usage of indium along with the ability to tune the band gap. Here we report successful synthesis of alloyed (CuInS2 )0.5(ZnS)0.5 nanocrystals by a method that solely uses oleylamine as the liquid medium for synthesis. The reactive sintering of a thin film of these nanocrystals via selenization at 500 °C results in a uniform composition alloy (CuIn(S,Se)2 )0.5 (Zn(S,Se)) 0.5 layer with mic...

  19. Influence of various surface pretreatments on adherence of sputtered molybdenum disulfide to silver, gold, copper, and bronze

    Science.gov (United States)

    Spalvins, T.

    1973-01-01

    Solid film lubricants of radio frequency sputtered molybdenum disulfide (MoS2) were applied to silver, gold, copper, and bronze surfaces that had various pretreatments (mechanical polishing, sputter etching, oxidation, and sulfurization). Optical and electron transmission micrographs and electron diffraction patterns were used to interpret the film formation characteristics and to evaluate the sputtering conditions in regard to the film and substrate compatibility. Sputtered MoS2 films flaked and peeled on silver, copper, and bronze surfaces except when the surfaces had been specially oxidized. The flaking and peeling was a result of sulfide compound formation and the corresponding grain growth of the sulfide film. Sputtered MoS2 films showed no peeling and flaking on gold surfaces regardless of surface pretreatment.

  20. A regenerable copper-based sorbent for H{sub 2}S removal from coal gases

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B. [Institute of Gas Technology, Des Plaines, IL (United States)

    1998-07-01

    This paper reports on research conducted for the development of copper-based sorbents for hot coal gas desulfurization applications in the temperature range of 550-650{degree}C. A thermodynamic analysis is given to rationalize the selection of chromia (Cr{sub 2}O{sub 3}), and its potential superiority to alumina (Al{sub 2}O{sub 3}), for the stabilization of copper oxide (Cu{sub 2}O) against complete reduction to elemental copper (Cu) upon exposure to a fuel gas in the indicated temperature range. The results of packed-bed experiments carried out for the determination of optimum operating conditions as well as the evaluation of the long-term durability and regenerability of a selected copper chromite sorbent was presented and discussed. The regenerable copper chromite sorbent developed, designated as CuCr-29, is capable of achieving less than 5 ppmv H{sub 2}S concentration in the cleaned fuel gas. The optimum desulfurization temperature in terms of sorbent efficiency (terminal H{sub 2}S levels in the cleaned fuel gas) and utilization (sulfur capacity at breakthrough or effective capacity) for this sorbent is determined to be about 600{degree}C. Sorbent regeneration with a dilute O{sub 2}-N{sub 2} gas mixture at 750{degree}C ensured complete conversion of the copper sulfide to oxide without sulfate formation or reactivity deterioration in subsequent cycles.

  1. Jiangxi Copper Plans to Increase its Refined Copper Output

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>According to news published on March 30th, China’s largest copper producer--Jiangxi Copper alleged in its 2010 Financial Report Statement that it plans to improve its output of refined copper by 4.4% in 2011, to increase from 900,000 tonnes last year to 940,000 tons.

  2. [Copper metabolism and genetic disorders].

    Science.gov (United States)

    Shimizu, Norikazu

    2016-07-01

    Copper is one of essential trace elements. Copper deficiency lead to growth and developmental failure and/or neurological dysfunction. However, excess copper is also problems for human life. There are two disorders of inborn error of copper metabolism, Menkes disease and Wilson disease. Menkes disease is an X linked recessive disorder with copper deficiency and Wilson disease is an autosomal recessive disorder with copper accumulation. These both disorders result from the defective functioning of copper transport P-type ATPase, ATP7A of Menkes disease and ATP7B of Wilson disease. In this paper, the author describes about copper metabolism of human, and clinical feature, diagnosis and treatment of Menkes disease and Wilson disease.

  3. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco.

    Science.gov (United States)

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild; Nielsen, Asbjørn Haaning

    2015-11-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit with some uncertainty. It was concluded that the model could be applied for the purpose in mind.

  4. High-quality draft genome sequence of Kocuria marina SO9-6, an actinobacterium isolated from a copper mine

    Science.gov (United States)

    Castro, Daniel B.A.; Pereira, Letícia Bianca; Silva, Marcus Vinícius M. e; Silva, Bárbara P. da; Palermo, Bruna Rafaella Z.; Carlos, Camila; Belgini, Daiane R.B.; Limache, Elmer Erasmo G.; Lacerda, Gileno V. Jr; Nery, Mariana B.P.; Gomes, Milene B.; Souza, Salatiel S. de; Silva, Thiago M. da; Rodrigues, Viviane D.; Paulino, Luciana C.; Vicentini, Renato; Ferraz, Lúcio F.C.; Ottoboni, Laura M.M.

    2015-01-01

    An actinobacterial strain, designated SO9-6, was isolated from a copper iron sulfide mineral. The organism is Gram-positive, facultatively anaerobic, and coccoid. Chemotaxonomic and phylogenetic properties were consistent with its classification in the genus Kocuria. Here, we report the first draft genome sequence of Kocuria marina SO9-6 under accession JROM00000000 (http://www.ncbi.nlm.nih.gov/nuccore/725823918), which provides insights for heavy metal bioremediation and production of compounds of biotechnological interest. PMID:26484219

  5. Transparent zinc sulfide processed from nanocrystalline powders

    Science.gov (United States)

    Gao, De; Stefanik, Todd S.

    2013-06-01

    Nanocerox produces oxide nanopowders via flame spray pyrolysis that have proven effective in the processing of a host of high quality optical ceramic materials. In order to produce LWIR windows to compete with ZnS, however, oxide materials are not suitable. Nanocerox has therefore developed aqueous synthesis techniques for the production of zinc sulfide nanopowders. The proprietary processing technique allows control of primary particle size, high purity, low levels of agglomeration, and cost effective synthesis. Crystallinity, particle size, and purity of the powders will be presented. Characterization of parts fabricated from these powders via sinter/HIP processing will also be discussed, including optical performance and microstructural characterization.

  6. Iron Sulfide Minerals in Black Sea Sediments

    Science.gov (United States)

    Franke, Christine; Robin, Eric; Henkel, Susann; Courtin-Nomade, Alexandra; Bleil, Ulrich

    2010-05-01

    This study presents a mutidisciplinary geochemical and environmental magnetic approach, integrating advanced mineralogical techniques to better understand the physicochemical syn-sedimentary and post-depositional processes in the anoxic sediments from the northwestern Black Sea. The investigated gravity core GC 214 was retrieved in 2007 during RV METEOR cruise M72/1 west of the Crimean Peninsula in a water depth of 1686 mbsf. Geochemical analyses of the pore water and solid phase indicate non-steady state sedimentation. The oxygen-depleted water column conditions, anaerobic oxidation of methane (AOM), and related microbial-driven sulfate reduction favor a highly complex iron sulfide mineral assemblage in the sediment column. The detailed magnetic susceptibility and remanence measurements indicate an irregularly stratified depth profile showing intervals of particularly high values. Further environmental magnetic analyses of hysteresis loops depict strongly elevated coercivity values for those depth horizons, suggesting metastable ferrimagnetic greigite (Fe3S4) as the main magnetic carrier phase. Automated chemical classification (ACC), using electron dispersive spectrometer (EDS) attached to a JEOL 840 scanning electron microscope (SEM) on dispersed particle samples permitted the absolutequantification of the various present iron mineral phases with depth, identified as greigite (Fe3S4), pyrrhotite (Fe7S8), pyrite (FeS2), and monosulfides (FeS), such as troilite or markasite. The statistically stable ACC analyses were carried out on magnetic extracts and density separates to be able to calculate budgets between the different present iron sulfides. We also obtained excellent correlations between the different iron sulfide concentrations and the magnetic signal, which open the possibility to link the absolute particle concentrations to the magnetic signal. Additional synchrotron based micro-XRD analyses on polished sections yield inside into the details of the

  7. Mercury Sulfide Dimorphism in Thioarsenate Glasses

    OpenAIRE

    KASSEM, Mohammad; Sokolov, Anton; Cuisset, Arnaud,; Usuki, Takeshi; Khaoulani, Sohayb; Masselin, Pascal; Le Coq, David,; Feygenson, M.; Benmore, C. J.; Hannon, Alex,; Neuefeind, J. C.; Bychkov, Eugene

    2016-01-01

    International audience; Crystalline mercury sulfide exists in two drastically different polymorphic forms in different domains of the P,T-diagram: red chain-like insulator α-HgS, stable below 344 °C, and black tetrahedral narrow-band semiconductor β-HgS, stable at higher temperatures. Using pulsed neutron and high-energy X-ray diffraction, we show that these two mercury bonding pattern are present simultaneously in mercury thioarsenate glasses HgS-As2S3. The population and interconnectivity o...

  8. Chinese Copper Manufacturers Expand Overseas

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>In 2012,China’s apparent copper consumption reached 8.84 million tons,accounting for 43%of the global total demand.Spurred by strong demand,China’s copper smelting capacity roars with annual average growth in domestic copper smelting capacity reaching approx-

  9. Understanding Cu release into environment from Kure massive sulfide ore deposits, Kastamonu, NW Turkey

    Science.gov (United States)

    Demirel, Cansu; Sonmez, Seref; Balci, Nurgul

    2014-05-01

    Covering a wide range on the earth's crust, oxidation of metal sulfide minerals have vital environmental impacts on the aquatic environment, causing one of the major environmental problems known as acid mine drainage (AMD). Located in the Kastamonu province of the Western Black Sea region, Kure district is one of the major copper mining sites in Turkey. Mining activities in the area heads back to ancient times, such that operation is thought to be started with the Roman Empire. Currently, only the underground mining tunnels of Bakibaba and Asikoy are being operated. Thus, mining heaps and ores of those pyritic deposits have been exposed to the oxidative conditions for so long. As a result of weathering processes of past and recent heaps of the Kure volcanic massive sulfide deposits in addition to the main ore mineral (chalcopyrite), significant amount of metals, especially Cu, are being released into the environment creating undesirable environmental conditions. In order to elucidate Cu release mechanisms from Kure pyritic ore deposits and mining wastes, field and laboratory approaches were used. Surface water and sediment samples from the streams around the mining and waste sites were collected. Groundwater samples from the active underground mining site were also collected. Physical parameters (pH, Eh, T°C, and EC) of water samples were determined in situ and in the laboratory using probes (WTW pH 3110, WTW Multi 9310 and CRISON CM 35). Metal and ion concentrations of the water samples were analysed using ICP-MS and DR 2800 spectrophotometer, respectively. High Cu, Co, Zn and Fe concentrations were determined in the water samples with pH values ranging from 2.9- 4. Cu concentrions ranges from 345 ppm to 36 ppm in the water samples. Consistent with the water samples, high Cu, Fe, Zn and Co were also determined in the sediment samples. Laboratory chalcopyrite oxidation experiments under the conditions representing the field site were set up as biological and

  10. Diurnal changes in pore water sulfide concentrations in the seagrass Thalassia testudinum beds: the effects of seagrasses on sulfide dynamics.

    Science.gov (United States)

    Lee; Dunton

    2000-12-20

    The dynamics of the seagrass-sulfide interaction were examined in relation to diel changes in sediment pore water sulfide concentrations in Thalassia testudinum beds and adjacent bare areas in Corpus Christi Bay and lower Laguna Madre, Texas, USA, during July 1996. Pore water sulfide concentrations in seagrass beds were significantly higher than in adjacent bare areas and showed strong diurnal variations; levels significantly decreased during mid-day at shallow sediment depths (0-10 cm) containing high below-ground tissue biomass and surface area. In contrast, diurnal variations in sediment sulfide concentrations were absent in adjacent bare patches, and at deeper (>10 cm) sediment depths characterized by low below-ground plant biomass or when the grasses were experimentally shaded. These observations suggest that the mid-day depressions in sulfide levels are linked to the transport of photosynthetically produced oxygen to seagrass below-ground tissues that fuels sediment sulfide oxidation. Lower sulfide concentrations in bare areas are likely a result of low sulfate reduction rates due to low organic matter available for remineralization. Further, high reoxidation rates due to rapid exchange between anoxic pore water and oxic overlying water are probably stimulated in bare areas by higher current velocity on the sediment surface than in seagrass beds. The dynamics of pore water sulfides in seagrass beds suggest no toxic sulfide intrusion into below-ground tissues during photosynthetic periods and demonstrate that the sediment chemical environment is considerably modified by seagrasses. The reduced sediment sulfide levels in seagrass beds during photosynthetic periods will enhance seagrass production through reduced sulfide toxicity to seagrasses and sediment microorganisms related to the nutrient cycling.

  11. Fabrication and Characterization of Metallic Copper and Copper Oxide Nanoflowers

    Directory of Open Access Journals (Sweden)

    *H. S. Virk

    2011-12-01

    Full Text Available Copper nanoflowers have been fabricated using two different techniques; electro-deposition of copper in polymer and anodic alumina templates, and cytyltrimethal ammonium bromide (CTAB-assisted hydrothermal method. Scanning Electron Microscope (SEM images record some interesting morphologies of metallic copper nanoflowers. Field Emission Scanning Electron Microscope (FESEM has been used to determine morphology and composition of copper oxide nanoflowers. X-ray diffraction (XRD pattern reveals the monoclinic phase of CuO in the crystallographic structure of copper oxide nanoflowers. There is an element of random artistic design of nature, rather than science, in exotic patterns of nanoflowers fabricated in our laboratory.

  12. Recent findings on sinks for sulfide in gravity sewer networks

    DEFF Research Database (Denmark)

    Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2006-01-01

    summarizes this newly obtained knowledge and emphasizes important implications of the findings. Model simulations of the in-sewer processes important for the sulfur cycle showed that sulfide oxidation in the wetted biofilm is typically the most important sink for dissolved sulfide in gravity sewers. However...

  13. Hydrogen sulfide: physiological properties and therapeutic potential in ischaemia.

    Science.gov (United States)

    Bos, Eelke M; van Goor, Harry; Joles, Jaap A; Whiteman, Matthew; Leuvenink, Henri G D

    2015-03-01

    Hydrogen sulfide (H2 S) has become a molecule of high interest in recent years, and it is now recognized as the third gasotransmitter in addition to nitric oxide and carbon monoxide. In this review, we discuss the recent literature on the physiology of endogenous and exogenous H2 S, focusing upon the protective effects of hydrogen sulfide in models of hypoxia and ischaemia.

  14. Separation of copper flotation concentrates into density fractions by means of polytungstate aqueous solution

    Directory of Open Access Journals (Sweden)

    Luszczkiewicz Andrzej

    2016-01-01

    Full Text Available Industrial and laboratory flotation copper concentrates were subjected to separation into density fractions by means of heavy liquids in the form of sodium polytungstate aqueous solutions. For two samples, three densities factions were created, however in different density ranges. The density fractions were analyzed to establish the content of copper, lead, silver and organic carbon. The size of particles in both samples was similar (90-95% −0.071 mm. It was found that the lightest density fractions −2.45 and −2.0 g/cm3 still contained sulfide minerals scattered in the organic carbon bearing particles. Removal of the lightest density fraction (−2.0 g/cm3 from the industrial concentrate samples led to considerable reduction of organic carbon (92% and increasing its quality from 13 to 28% Cu. The mineralogical analysis of the heavy liquid separation products showed that most sulfide minerals were evenly dissemination in the heaviest density fractions with the recovery of 95-98%. The lightest density fraction of −2.0 g/cm3, being the richest in organic carbon, contained approximately 3% of unliberated sulfide minerals.

  15. Copper and Copper Proteins in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Sergio Montes

    2014-01-01

    Full Text Available Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson’s disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson’s disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson’s disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson’s disease and that a mutation in ATP7B could be associated with Parkinson’s disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

  16. Industrial experiment of copper electrolyte purification by copper arsenite

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ya-jie; XIAO Fa-xin; WANG Yong; LI Chun-hua; XU Wei; JIAN Hong-sheng; MA Yut-ian

    2008-01-01

    Copper electrolyte was purified by copper arsenite that was prepared with As2O3. And electrolysis experiments of purified electrolyte were carried out at 235 and 305 A/m2, respectively. The results show that the yield of copper arsenite is up to 98.64% when the molar ratio of Cu to As is 1.5 in the preparation of copper arsenite. The removal rates of Sb and Bi reach 74.11% and 65.60% respectively after copper arsenite is added in electrolyte. The concentrations of As, Sb and Bi in electrolyte nearly remain constant during electrolysis of 13 d. The appearances of cathode copper obtained at 235 and 305 A/m2 are slippery and even, and the qualification rate is 100% according to the Chinese standard of high-pure cathode copper(GB/T467-97).

  17. Effect of palladium on sulfide tarnishing of noble metal alloys.

    Science.gov (United States)

    Suoninen, E; Herø, H; Minni, E

    1985-10-01

    Electron spectroscopic studies of Au-Ag-Cu alloys of the type used for dental castings show that small additions (less than or equal to 3 wt%) of palladium reduce essentially the thickness of the sulfide layer formed on surfaces of samples treated in aqueous Na2S solutions. Relative to silver, palladium does not enrich in the sulfide, but statistically significant enrichment is found immediately below the sulfide layer. This enrichment probably takes place during the exposure of the substrate surface to atmosphere before the sulfiding treatment. The mechanism of the impeding effect of palladium on sulfiding is assumed to be a decrease in diffusion from the bulk alloy to the surface due to the enriched layer. The effect cannot be explained by changes in the electronic structure of the alloy due to palladium alloying.

  18. Sulindac Sulfide, but Not Sulindac Sulfone, Inhibits Colorectal Cancer Growth

    Directory of Open Access Journals (Sweden)

    Christopher S. Williams

    1999-06-01

    Full Text Available Sulindac sulfide, a metabolite of the nonsteroidal antiinflammatory drug (NSAID sulindac sulfoxide, is effective at reducing tumor burden in both familial adenomatous polyposis patients and in animals with colorectal cancer. Another sulindac sulfoxide metabolite, sulindac sulfone, has been reported to have antitumor properties without inhibiting cyclooxygenase activity. Here we report the effect of sulindac sulfone treatment on the growth of colorectal carcinoma cells. We observed that sulindac sulfide or sulfone treatment of HCA-7 cells led to inhibition of prostaglandin E2 production. Both sulindac sulfide and sulfone inhibited HCA-7 and HCT-116 cell growth in vitro. Sulindac sulfone had no effect on the growth of either HCA-7 or HCT-116 xenografts, whereas the sulfide derivative inhibited HCA-7 growth in vivo. Both sulindac sulfide and sulfone inhibited colon carcinoma cell growth and prostaglandin production in vitro, but sulindac sulfone had no effect on the growth of colon cancer cell xenografts in nude mice.

  19. Influence of Water Salinity on Air Purification from Hydrogen Sulfide

    Directory of Open Access Journals (Sweden)

    Leybovych L.I.

    2015-12-01

    Full Text Available Mathematical modeling of «sliding» water drop motion in the air flow was performed in software package FlowVision. The result of mathematical modeling of water motion in a droplet with diameter 100 microns at the «sliding» velocity of 15 m/s is shown. It is established that hydrogen sulfide oxidation occurs at the surface of phases contact. The schematic diagram of the experimental setup for studying air purification from hydrogen sulfide is shown. The results of the experimental research of hydrogen sulfide oxidation by tap and distilled water are presented. The dependence determining the share of hydrogen sulfide oxidized at the surface of phases contact from the dimensionless initial concentration of hydrogen sulfide in the air has been obtained.

  20. Hierarchical Architecturing for Layered Thermoelectric Sulfides and Chalcogenides

    Directory of Open Access Journals (Sweden)

    Priyanka Jood

    2015-03-01

    Full Text Available Sulfides are promising candidates for environment-friendly and cost-effective thermoelectric materials. In this article, we review the recent progress in all-length-scale hierarchical architecturing for sulfides and chalcogenides, highlighting the key strategies used to enhance their thermoelectric performance. We primarily focus on TiS2-based layered sulfides, misfit layered sulfides, homologous chalcogenides, accordion-like layered Sn chalcogenides, and thermoelectric minerals. CS2 sulfurization is an appropriate method for preparing sulfide thermoelectric materials. At the atomic scale, the intercalation of guest atoms/layers into host crystal layers, crystal-structural evolution enabled by the homologous series, and low-energy atomic vibration effectively scatter phonons, resulting in a reduced lattice thermal conductivity. At the nanoscale, stacking faults further reduce the lattice thermal conductivity. At the microscale, the highly oriented microtexture allows high carrier mobility in the in-plane direction, leading to a high thermoelectric power factor.

  1. Mechanical properties of gutta-percha sulfide modified asphalt

    Science.gov (United States)

    Zou, X. Y.; Gu, X. Y.; Wang, X. W.

    2017-01-01

    Gutta-percha is the isomer of caoutchouc and can be used to enhance the performance of asphalt. In this paper, the produce proceedings of gutta-percha sulfide and gutta-percha sulfide modified asphalt are introduced. The performance indices of gutta-percha sulfide modified asphalt samples with different proportions are examined based on laboratory tests and the optimum ratio of gutta-percha and sulfur is decided.The micromechanism, temperature sensitivity, high and low temperature properties and viscoelasticity of the polymer modified asphalt are analyzed to discuss the modified mechanism and to decide the optimal polymer content. Low temperature bending tests are carried out to verify the low temperature performance of gutta-percha sulfide modified asphalt mixture. Research results showed that gutta-percha sulfide modified asphalt has good low temperature performance and a promising application prospect in the cold regions.

  2. Regulation of bacterial sulfate reduction and hydrogen sulfide fluxes in the central Namibian coastal upwelling zone

    DEFF Research Database (Denmark)

    Bruchert, V.; Jørgensen, BB; Neumann, K.;

    2003-01-01

    and the low capacity to oxidize and trap sulfide. The inner shelf break marks the seaward border of sulfidic bottom waters, and separates two different regimes of bacterial sulfate reduction. In the sulfidic bottom waters on the shelf, up to 55% of sulfide oxidation is mediated by the large nitrate...... to the sediment-water interface and reduce the hydrogen sulfide flux to the water column. Modeling of pore water sulfide concentration profiles indicates that sulfide produced by bacterial sulfate reduction in the uppermost 16 cm of sediment is sufficient to account for the total flux of hydrogen sulfide...... to the water column. However, the total pool of hydrogen sulfide in the water column is too large to be explained by steady state diffusion across the sediment-water interface. Episodic advection of hydrogen sulfide, possibly triggered by methane eruptions, may contribute to hydrogen sulfide in the water...

  3. Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

    2014-11-04

    Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

  4. Condition Monitoring of Corrosive Sulfur Reaction in Transformer by Copper Ion Analysis%利用铜离子质量分数监测变压器中硫腐蚀状态的研究

    Institute of Scientific and Technical Information of China (English)

    万涛; 钱晖; 冯兵; 周舟; 龚尚昆

    2013-01-01

    In order to investigate monitoring methods of sulfur corrosion in transformer,the copper content in oil and the sulfur-corrosion test results of 40 operating transformers were compared.Moreover,dynamic copper strip corrosion was tested by simulation in transformer oil samples filled with nitrogen,air and oxygen,respectively,and the change of copper content in oil and copper sulfide on copper strip and the influence of oxygen in the corrosion process were determined.The results showed that the consistency between the copper content tests and the corrosive sulfur tests exceeded 70%.The amounts of copper ion in oil and cuprous sulfide on copper strip both increased while the corrosion developed,indicating that copper corrosion of a transformer could be effectively monitored through copper content analysis.Meanwhile,corrosive sulfur tests could accurately reflect the accumulation of cuprous sulfide on copper strip from the color of copper strip.In the absence of oxygen,the main copper corrosion process should be copper→copper complex ion→cuprous sulfide,and the oxygen-contained copper corrosion process includes both copper→ copper oxide→copper complex ion→cuprous sulfide and copper→copper complex ion→cuprous sulfide.%为了研究变压器中硫腐蚀作用的监测方法,考察了40台运行变压器油中铜离子质量分数与腐蚀性硫测试结果的关系.将变压器油样品充入氮气、空气和氧气条件下进行了腐蚀过程动态模拟试验,确定了铜腐蚀过程中油中铜离子和铜片表面元素含量变化的规律和氧气含量的影响.结果表明,铜离子质量分数检测与腐蚀性硫试验一致性>70%,油中铜离子和铜片表面硫化亚铜离子质量分数随腐蚀过程不断增加,通过铜离子质量分数检测能够有效监测变压器铜腐蚀状态;腐蚀性硫试验中铜片颜色能够准确反映硫化亚铜离子质量分数变化.不含氧气时,铜的腐蚀过程主

  5. Calculation of sulfide capacities of multicomponent slags

    Science.gov (United States)

    Pelton, Arthur D.; Eriksson, Gunnar; Romero-Serrano, Antonio

    1993-10-01

    The Reddy-Blander model for the sulfide capacities of slags has been modified for the case of acid slags and to include A12O3 and TiO2 as components. The model has been extended to calculate a priori sulfide capacities of multicomponent slags, from a knowledge of the thermodynamic activities of the component oxides, with no adjustable parameters. Agreement with measurements is obtained within experimental uncertainty for binary, ternary, and quinary slags involving the components SiO2-Al2O3-TiO2-CaO-MgO-FeO-MnO over wide ranges of composition. The oxide activities used in the computations are calculated from a database of model parameters obtained by optimizing thermodynamic and phase equilibrium data for oxide systems. Sulfur has now been included in this database. A computing system with automatic access to this and other databases has been developed to permit the calculation of the sulfur content of slags in multicomponent slag/metal/gas/solid equilibria.

  6. Hydrogen sulfide and polysulfides as biological mediators.

    Science.gov (United States)

    Kimura, Hideo

    2014-10-09

    Hydrogen sulfide (H2S) is recognized as a biological mediator with various roles such as neuromodulation, regulation of the vascular tone, cytoprotection, anti-inflammation, oxygen sensing, angiogenesis, and generation of mitochondrial energy. It is produced by cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST). The activity of CBS is enhanced by S-adenosyl methionine (SAM) and glutathionylation, while it is inhibited by nitric oxide (NO) and carbon monoxide (CO). The activity of CSE and cysteine aminotransferase (CAT), which produces the 3MST substrate 3-mercaptopyruvate (3MP), is regulated by Ca2+. H2S is oxidized to thiosulfate in mitochondria through the sequential action of sulfide quinone oxidoreductase (SQR), sulfur dioxygenase, and rhodanese. The rates of the production and clearance of H2S determine its cellular concentration. Polysulfides (H2Sn) have been found to occur in the brain and activate transient receptor potential ankyrin 1 (TRPA1) channels, facilitate the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus, and suppress the activity of phosphatase and tensin homolog (PTEN) by sulfurating (sulfhydrating) the target cysteine residues. A cross talk between H2S and NO also plays an important role in cardioprotection as well as regulation of the vascular tone. H2S, polysulfides, and their cross talk with NO may mediate various physiological and pathophysiological responses.

  7. First detection of doubly deuterated hydrogen sulfide

    CERN Document Server

    Vastel, C; Ceccarelli, C; Pearson, J

    2003-01-01

    This work was carried out with using the Caltech Submillimeter Observatory and presents the observational study of HDS and D2S towards a sample of Class 0 sources, and dense cores. We report the first detection of doubly deuterated hydrogen sulfide (D2S) in two dense cores and analyze the chemistry of these molecules aiming to help understand the deuteration processes in the interstellar medium. The observed values of the D2S/HDS ratio, and upper limits, require an atomic D/H ratio in the accreting gas of 0.1-1. The study presented in this Letter supports the hypothesis that formaldehyde, methanol and hydrogen sulfide are formed on the grain surfaces, during the cold pre-stellar core phase, where the CO depleted gas has large atomic D/H ratios. The high values for the D/H ratios are consistent with the predictions of a recent gas-phase chemical model that includes H3+ and its deuterated isotopomers, H2D+, D2H+ and D3+ (Roberts et al. 2003).

  8. Hydrogen Sulfide and Polysulfides as Biological Mediators

    Directory of Open Access Journals (Sweden)

    Hideo Kimura

    2014-10-01

    Full Text Available Hydrogen sulfide (H2S is recognized as a biological mediator with various roles such as neuromodulation, regulation of the vascular tone, cytoprotection, anti-inflammation, oxygen sensing, angiogenesis, and generation of mitochondrial energy. It is produced by cystathionine β-synthase (CBS, cystathionine γ-lyase (CSE, and 3-mercaptopyruvate sulfurtransferase (3MST. The activity of CBS is enhanced by S-adenosyl methionine (SAM and glutathionylation, while it is inhibited by nitric oxide (NO and carbon monoxide (CO. The activity of CSE and cysteine aminotransferase (CAT, which produces the 3MST substrate 3-mercaptopyruvate (3MP, is regulated by Ca2+. H2S is oxidized to thiosulfate in mitochondria through the sequential action of sulfide quinone oxidoreductase (SQR, sulfur dioxygenase, and rhodanese. The rates of the production and clearance of H2S determine its cellular concentration. Polysulfides (H2Sn have been found to occur in the brain and activate transient receptor potential ankyrin 1 (TRPA1 channels, facilitate the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2 to the nucleus, and suppress the activity of phosphatase and tensin homolog (PTEN by sulfurating (sulfhydrating the target cysteine residues. A cross talk between H2S and NO also plays an important role in cardioprotection as well as regulation of the vascular tone. H2S, polysulfides, and their cross talk with NO may mediate various physiological and pathophysiological responses.

  9. Carbonyl sulfide: No remedy for global warming

    Science.gov (United States)

    Taubman, Steven J.; Kasting, James F.

    1995-04-01

    The enhancement of the stratospheric aerosol layer caused by the eruption of Mt. Pinatubo (June 15, 1991), and the subsequent cooling of the earth's lower atmosphere [Dutton and Christy, 1992; Minnis et al., 1993] shows that stratospheric aerosols can have a strong effect on the earth's climate. This supports the notion that the intentional enhancement of the stratospheric aerosol layer through increased carbonyl sulfide (OCS) emissions might be an effective means for counteracting global warming. Through the use of a one-dimensional photochemical model, we investigate what effect such a program might have on global average stratospheric ozone. In addition, we consider the impact of enhanced OCS emissions on rainwater acidity and on the overall health of both plants and animals. We find that while the warming produced by a single CO2 doubling (1 to 4°C) might be offset with ozone losses of less than 5%, any attempt to use carbonyl sulfide as a permanent solution to global warming could result in depletion of global average ozone by 30% or more. We estimate that in order to achieve cooling of 4°C rainwater pH would fall to between 3.5 and 3.8. Finally, a 4°C cooling at the surface will require that ambient near ground OCS levels rise to above 10 ppmv which is probably greater than the safe exposure limit for humans. Thus, enhanced OCS emissions do not provide an environmentally acceptable solution to the problem of global warming.

  10. Normal state of metallic hydrogen sulfide

    Science.gov (United States)

    Kudryashov, N. A.; Kutukov, A. A.; Mazur, E. A.

    2017-02-01

    A generalized theory of the normal properties of metals in the case of electron-phonon (EP) systems with a nonconstant density of electron states has been used to study the normal state of the SH3 and SH2 phases of hydrogen sulfide at different pressures. The frequency dependence of the real Re Σ (ω) and imaginary ImΣ (ω) parts of the self-energy Σ (ω) part (SEP) of the Green's function of the electron Σ (ω), real part Re Z (ω), and imaginary part Im Z (ω) of the complex renormalization of the mass of the electron; the real part Re χ (ω) and the imaginary part Imχ (ω) of the complex renormalization of the chemical potential; and the density of electron states N (ɛ) renormalized by strong electron-phonon interaction have been calculated. Calculations have been carried out for the stable orthorhombic structure (space group Im3¯ m) of the hydrogen sulfide SH3 for three values of the pressure P = 170, 180, and 225 GPa; and for an SH2 structure with a symmetry of I4/ mmm ( D4 h1¯7) for three values of pressure P = 150, 180, and 225 GP at temperature T = 200 K.

  11. CALCULATION OF CONDITIONAL EQUILIBRIUM IN SERIAL MULTIPLE PRECIPITATION OF METAL SULFIDES WITH HYDROGEN SULFIDE STREAM GENERATED FROM SODIUM SULFIDE: A DIDACTIC TOOL FOR CHEMISTRY TEACHING

    Directory of Open Access Journals (Sweden)

    Renata Bellová

    2016-07-01

    Full Text Available Hydrogen sulfide is presented in textbooks as toxic, environmentally unacceptable species, however some positive effects in human metabolism were discovered in the last decades. It is important to offer students also some new information about this compound. As didactic tool in this case may serve serial precipitation of Cd2+, Cu2+, Zn2+, Mn2+ and Pb2+ ions forming various colored sulfides in bubblers with chemically generated hydrogen sulfide stream. This experiment has strong and diverse color effect for enhancing the visual perception to motivate students to understand more abstract and complex information about hydrogen sulfide. It also may be helpful in analytical chemistry courses for conditional precipitation equilibrium teaching and calculations.

  12. The Effect of Copper

    African Journals Online (AJOL)

    higher (p<0.05) in the broodfish fed CSD0 and CSD1 diets than the other diets. Exposure of Clarias gariepinus fish to copper in water, at concentrations above 1.0mg CuSO4/g elicits adverse ... introduction of a toxicant to an aquatic system ..... Toxicity of four commonly used agrochemicals on. Oreochromis niloticus (L) fry.

  13. Presenilin promotes dietary copper uptake.

    Directory of Open Access Journals (Sweden)

    Adam Southon

    Full Text Available Dietary copper is essential for multicellular organisms. Copper is redox active and required as a cofactor for enzymes such as the antioxidant Superoxide Dismutase 1 (SOD1. Copper dyshomeostasis has been implicated in Alzheimer's disease. Mutations in the presenilin genes encoding PS1 and PS2 are major causes of early-onset familial Alzheimer's disease. PS1 and PS2 are required for efficient copper uptake in mammalian systems. Here we demonstrate a conserved role for presenilin in dietary copper uptake in the fly Drosophila melanogaster. Ubiquitous RNA interference-mediated knockdown of the single Drosophila presenilin (PSN gene is lethal. However, PSN knockdown in the midgut produces viable flies. These flies have reduced copper levels and are more tolerant to excess dietary copper. Expression of a copper-responsive EYFP construct was also lower in the midgut of these larvae, indicative of reduced dietary copper uptake. SOD activity was reduced by midgut PSN knockdown, and these flies were sensitive to the superoxide-inducing chemical paraquat. These data support presenilin being needed for dietary copper uptake in the gut and so impacting on SOD activity and tolerance to oxidative stress. These results are consistent with previous studies of mammalian presenilins, supporting a conserved role for these proteins in mediating copper uptake.

  14. Effect of sulfide pollution on the stability of Cu–Al–5Ni alloy in 3.5% NaCl solution

    Directory of Open Access Journals (Sweden)

    Nady H. El-Sayed

    2014-06-01

    Full Text Available The stability of Cu–Al–5Ni ternary alloy used in the manufacture of NaCl and Na2SO4 from the Lake Qaroun in Egypt was investigated in 3.5% NaCl in the presence of sulfide ions. The electrochemical reactions of Cu–Al–5Ni electrode in the test solutions were studied using electrochemical impedance spectroscopy measurements. In addition surface examination and morphological studies were applied using scanning electron microscopy (SEM and energy dispersive analysis of X-rays (EDAX. The results of impedance measurements at open circuit potential have shown that the overall impedance of the system decreases with the increase in sulfide ion concentration and increases with immersion time due to continuous growth of the passive film on the alloy surface. The EDAX analysis showed the presence of copper, aluminum and nickel compounds, Cu-oxides, Cu-chlorides and Cu2S on the alloy surface.

  15. Comparative characteristics of copper, copper chloride, and copper bromide vapor lasers

    Energy Technology Data Exchange (ETDEWEB)

    Kazarian, M.A.; Petrash, G.G.; Trofimov, A.N.

    1980-03-01

    The paper reports the results of a comparative study of copper and copper halide vapor lasers emitting in a repetitively-pulsed regime. Copper chloride and copper bromide vapor lasers are found to have identical lasing characteristics under any excitation conditions. These characteristics are different from those of a copper vapor laser. An average lasing power of 13 W has been obtained for all lasers studied for an efficiency of 1%. It is shown that the choice of a laser will largely depend on the laser design suitability for a specific application.

  16. Association of pyrobitumen with copper mineralization from the Uchumi and Talcuna districts, central Chile

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Nicholas S.F.; Zentilli, Marcos [Geological Survey of Canada Calgary, 3303-33rd St. N.W., Calgary (AB Canada T2L 2A7)

    2006-01-03

    Pyrobitumen has been shown to be an essential component in formation of some Chilean manto-type (strata-bound) copper deposits and its presence has been observed in a number of other deposits but has received limited investigation. In this paper we present paragenetic and geochemical data from two central Chilean manto-type deposits from the Uchumi and Talcuna districts where solid pyrobitumen (residual petroleum) is intimately associated with copper sulfides. Pyrobitumen in the Uchumi deposit occurs in pore space within the host conglomerates and is adjacent to a granitoid stock; pyrobitumen predates bornite-chalcocite mineralization and may have reduced subsequent mineralizing fluids. Pyrobitumen from the Manto Delirio deposit, Talcuna District, fills the cores of early sphalerite veins and was partially replaced by later Cu-As mineralization; pyrobitumen is petrographically intergrown with Cu-Fe sulfides and light {delta}{sup 13}C values of gangue calcite indicates the interaction of pyrobitumen with the mineralizing fluid. The presence of pyrobitumen within the ores of other manto-type copper deposits in the Lower Cretaceous basin of Chile suggests that degraded petroleum reservoirs, in particular if biodegradation generated authigenic pyrite, can be important controls for metallic mineralization derived from hydrothermal solutions of different sources. (author)

  17. Development of novel copper-based sorbents for hot gas cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Hill, A.H.; Abbasian, J. (Institute of Gas Technology, Chicago, IL (United States)); Flytzani-Stephanopoulos, M.; Bo, L.; Li, Li. (Massachusetts Inst. of Tech., Cambridge, MA (United States)); Honea, F.I. (Illinois Clean Coal Inst., Carterville, IL (United States))

    1993-01-01

    The objective of this investigation is to evaluate two novel copper-based sorbents (i.e. copper-chromium and copper-cerium) for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650[degree] to 850[degree]C. New sorbent compositions from the selected Cu-Cr-O and Cu-Ce-O binary oxides were prepared and characterized by BET N[sub 2]-desorption surface area measurement following various calcination/time-temperature exposures. The general trends reported last quarter (on 11 different compositions) were validated this quarter in that both binary oxides lose surface area as the amount of CuO is increased. Time-resolved sulfidation tests were conducted at 850[degree]C using the equimolar CuO.Cr[sub 2]O[sub 3] composition. The two selected binary oxides prepared in larger qauntities (for testing in a two-inch reactor) have physical properties typical of the sorbents prepared in past programs. Two multicycle desulfurization tests, conducted this quarter on the Cu-Ce-O sorbent at 850[degree]C, using a feed gas containing 5000 ppm H[sub 2]S, 10 vol % H[sub 2] and 10 vol % H[sub 2]O at a space velocity (STP) of 2000 h[sup [minus]1], demonstrated high sulfur removal efficiency for the first one or two cycles, and a significant reduction in efficiency in the following cycles.

  18. Synthesis of Diaryl Ethers, Diaryl Sulfides, Heteroaryl Ethers and Heteroaryl Sulfides under Microwave Heating

    Institute of Scientific and Technical Information of China (English)

    LI,Feng; ZOU,Jiong; WANG,Quan-Rui; TAO,Feng-Gang

    2004-01-01

    @@ Diaryl ether moiety is found in a pool of naturally occurring and medicinally important compounds.[1] As a consequent, considerable efforts have been devoted to the assembly of this framework.[2] Recently, we have developed a microwave heating version of the synthesis of diaryl ethers as well as aryl sulfides. Under our conditions, even the extremely electron-poor 4-nitrophenol works well and its reaction with 1-halo-4-nitrobenzenes produces 4-(nitrophenoxy)-benzonitriles in satisfactory yield. The scope of the present protocol has been expanded to hydroxylated six-membered heterocycles as well as 2-pyrimidinethiol with mildly activated aryl halides, affording heteroaryl ethers and respectively sulfides. The advantages of the present method include the wide substrate scope, no use of any metal catalysts, the ease of product isolation and high yields.

  19. Structural, optical, photoluminescence and antibacterial properties of copper-doped silver sulfide nanoparticles.

    Science.gov (United States)

    Fakhri, Ali; Pourmand, Melika; Khakpour, Reza; Behrouz, Sajjad

    2015-08-01

    The Ag2S and Cu doped Ag2S nanoparticles were prepared by simple chemical co-precipitation method and characterized by XRD, SEM, EDX, TEM, PL and UV-vis spectra. The photocatalytic activity of Ag2S and Cu doped Ag2S nanoparticles were investigated with Ofloxacin antibiotic, which is part of the fluoroquinolone family. The morphological study indicated that the products were spherical shape in with diameter size of 30nm. The photocatalytic results demonstrated that the Cu doping increased the photocatalytic efficiency of Ag2S nanoparticles. The outcome of antibacterial experiment under visible light irradiation indicate that the Cu doped Ag2S nanoparticles represent increased antibacterial performance compared with un-doped Ag2S nanoparticles. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Acetylene black incorporated layered copper sulfide nanosheets for high-performance supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ke-Jing, E-mail: kejinghuang11@163.com; Zhang, Ji-Zong; Jia, Yu-Ling; Xing, Ke; Liu, Yan-Ming

    2015-08-25

    Highlights: • CuS/AB composites were synthesized by a simple solvothermal route. • Supercapacitor electrode based on CuS/AB was fabricated. • Microstructures and electrochemical properties of the electrodes were evaluated. • CuS/AB electrode exhibited ultrahigh specific capacitance and good cycling stability. - Abstract: Two-dimensional transition metal chalcogenides are attracting increasing attention in energy storage due to their unique structures and electronic properties. CuS has been demonstrated with a metal-like electronic conductivity and a high theoretical capacity. In this work, a facile strategy was reported for one-step synthesis of acetylene black (AB) incorporated layered CuS nanosheet via a simple solvothermal route. X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy were used to investigate the morphologies and microstructures of the as-prepared materials. Electrochemical data showed that the CuS/AB composites displayed a high specific capacitance of 2981 F/g at 1.0 A/g and retained 64.6% (1924.5 F/g) at a high current density of 20 A/g, indicative of good rate capability. Furthermore, the composites retained approximately 92% of the initial specific capacitance after 600 cycles at a current density of 1.0 A/g, demonstrating good cycling stability. The outstanding electrochemical properties of the CuS/AB composite suggested that it had great potential for practical applications in high-performance supercapacitors and the present synthesis strategy maybe readily extended to the preparation of other composites based on CuS for potential applications in energy storage and conversion devices.

  1. Combinatorial photothermal and immuno cancer therapy using chitosan-coated hollow copper sulfide nanoparticles.

    Science.gov (United States)

    Guo, Liangran; Yan, Daisy D; Yang, Dongfang; Li, Yajuan; Wang, Xiaodong; Zalewski, Olivia; Yan, Bingfang; Lu, Wei

    2014-06-24

    Near-infrared light-responsive inorganic nanoparticles have been shown to enhance the efficacy of cancer photothermal ablation therapy. However, current nanoparticle-mediated photothermal ablation is more effective in treating local cancer at the primary site than metastatic cancer. Here, we report the design of a near-infrared light-induced transformative nanoparticle platform that combines photothermal ablation with immunotherapy. The design is based on chitosan-coated hollow CuS nanoparticles that assemble the immunoadjuvants oligodeoxynucleotides containing the cytosine-guanine (CpG) motifs. Interestingly, these structures break down after laser excitation, reassemble, and transform into polymer complexes that improve tumor retention of the immunotherapy. In this "photothermal immunotherapy" approach, photothermal ablation-induced tumor cell death reduces tumor growth and releases tumor antigens into the surrounding milieu, while the immunoadjuvants potentiate host antitumor immunity. Our results indicated that combined photothermal immunotherapy is more effective than either immunotherapy or photothermal therapy alone against primary treated and distant untreated tumors in a mouse breast cancer model. These hollow CuS nanoparticles are biodegradable and can be eliminated from the body after laser excitation.

  2. Morphology of Copper Tin Sulfide Films Grown by Pulsed Laser Deposition at 248 and 355 nm

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Cazzaniga, Andrea Carlo; Crovetto, Andrea;

    Thin films solar cells based on Cu2ZnSnS4 (CZTS) as absorber layer have seen a rapid development leading to a world record of 8.8% [1]. However, other p-type semiconductors with fewer elements and reduced complexity compared to CZTS are also available, such as ternary Cu–Sn–S systems, i.e. Cu2SnS3...

  3. Chemical spray pyrolysis of copper indium diselenide/cadmium sulfide solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Brown, B.J.

    1989-01-01

    This dissertation concentrates on Chemical Spray Pyrolysis (CSP) of CuInSe{sub 2} and CdS thin films and solar cells. The primary goal is to gain an understanding of the chemistry and physics of CSP, and apply this knowledge to the fabrication of CuInSe{sub 2}/CdS solar cells. It provide an extensive review of the literature on the properties of CuInSe{sub 2} an CdS produced by CSP and other techniques. The films are characterized by x-ray diffractometry, scanning electron microscopy, electron microprobe, van der Pauw-Hall measurements, and optical absorption spectroscopy, and the devices are characterized electrically in the dark and under illumination. A model for the chemical mechanisms involved in CSP of CdS an CuInSe{sub 2} thin films is developed which is used to point out similarities between the two systems and explain the correlation between spray solution pH and second phases in CuInSe{sub 2} thin films. Structural investigations show that the CuInSe{sub 2} films can be produced in either the ordered or disordered crystal structure, while different substrates radically change the morphology of the films. By taking into account the effect of second phases, the electrical and optical properties of the sprayed films agree with published results for CuInSe{sub 2} produced by other techniques. The properties of the sprayed CdS films in this work are shown to agree with those sprayed by others. The device properties of cells fabricated in both the backwall and reverse backwall configuration are compared with each other and related to the materials properties of the semiconductor layers. The highest efficiency cell employing sprayed CuInSe{sub 2} is reported; however, the efficiency of the cells still need improvement before becoming practical. The dissertation concludes with recommendations for increasing the efficiency of completely sprayed CuInSe{sub 2}/CdS solar cells.

  4. Preparation and characterization of nanocomposite between poly(aniline-co-m-chloroaniline)-copper sulfide nanoparticles

    Science.gov (United States)

    Abbas, Saeed J.; Rani, Mamta; Tripathi, S. K.

    2014-06-01

    One dimensional nanostructures of poly(aniline-co-m-chloroaniline) nanocomposite (NC) with CuS nanoparticles (NPs) are prepared by template free method. CuS NPs are prepared by chemical method by using trisodium nitilotriacetate acid as a complexing agent. The materials are characterized by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Ultraviolet spectroscopy (UV-Vis), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TGA). The hexagonal structure of CuS NPs is confirmed from XRD results with lattice parameters, a=3.78 Å and c=16.288 Å. The diameter of CuS NPs is found to be 16 nm from TEM measurements. Different shapes such as NPs, nanorods and nanotubes structures are observed for poly(aniline-co-m-chloroaniline) whereas its NC with CuS NPs have nanorod and nanotube shapes. Significant shift in the absorption edge of CuS NC is observed in comparison with copolymer and CuS NPs. Also the thermal stability of CuS NC is improved as compared with a copolymer and CuS NPs.

  5. Preparation and characterization of nanocomposite between poly(aniline-co-m-chloroaniline)–copper sulfide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, Saeed J.; Rani, Mamta; Tripathi, S.K., E-mail: surya@pu.ac.in

    2014-06-15

    One dimensional nanostructures of poly(aniline-co-m-chloroaniline) nanocomposite (NC) with CuS nanoparticles (NPs) are prepared by template free method. CuS NPs are prepared by chemical method by using trisodium nitilotriacetate acid as a complexing agent. The materials are characterized by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Ultraviolet spectroscopy (UV-Vis), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TGA). The hexagonal structure of CuS NPs is confirmed from XRD results with lattice parameters, a=3.78 Å and c=16.288 Å. The diameter of CuS NPs is found to be 16 nm from TEM measurements. Different shapes such as NPs, nanorods and nanotubes structures are observed for poly(aniline-co-m-chloroaniline) whereas its NC with CuS NPs have nanorod and nanotube shapes. Significant shift in the absorption edge of CuS NC is observed in comparison with copolymer and CuS NPs. Also the thermal stability of CuS NC is improved as compared with a copolymer and CuS NPs.

  6. Azo dye decolorization assisted by chemical and biogenic sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

    2013-04-15

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

  7. Measurement of plasma hydrogen sulfide in vivo and in vitro.

    Science.gov (United States)

    Shen, Xinggui; Pattillo, Christopher B; Pardue, Sibile; Bir, Shyamal C; Wang, Rui; Kevil, Christopher G

    2011-05-01

    The gasotransmitter hydrogen sulfide is known to regulate multiple cellular functions during normal and pathophysiological states. However, a paucity of concise information exists regarding quantitative amounts of hydrogen sulfide involved in physiological and pathological responses. This is primarily due to disagreement among various methods employed to measure free hydrogen sulfide. In this article, we describe a very sensitive method of measuring the presence of H₂S in plasma down to nanomolar levels, using monobromobimane (MBB). The current standard assay using methylene blue provides erroneous results that do not actually measure H₂S. The method presented herein involves derivatization of sulfide with excess MBB in 100 mM Tris-HCl buffer (pH 9.5, 0.1 mM DTPA) for 30 min in 1% oxygen at room temperature. The fluorescent product sulfide-dibimane (SDB) is analyzed by RP-HPLC using an eclipse XDB-C18 (4.6 × 250 mm) column with gradient elution by 0.1% (v/v) trifluoroacetic acid in acetonitrile. The limit of detection for sulfide-dibimane is 2 nM and the SDB product is very stable over time, allowing batch storage and analysis. In summary, our MBB method is suitable for sensitive quantitative measurement of free hydrogen sulfide in multiple biological samples such as plasma, tissue and cell culture lysates, or media.

  8. Sulfide elimination by intermittent nitrate dosing in sewer sediments

    Institute of Scientific and Technical Information of China (English)

    Yanchen Liu; Chen Wu; Xiaohong Zhou; David Z.Zhu; Hanchang Shi

    2015-01-01

    The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards,and requires expensive programs for its prevention.The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments.The study was carried out based on lab-scale experiments and batch tests using real sewer sediments.The intermittent nitrate dosing mode and the optimal control condition were investigated.The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment.The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide)ratio with slight excess nitrate is necessary for optimal conditions ofefficient sulfide control with lower carbon source loss.The opth-nal control condition is feasible for the sulfide elimination in sewer systems.

  9. Intermetallic compounds, copper and palladium alloys in Au-Pd ore of the Skaergaard pluton, Greenland

    Science.gov (United States)

    Rudashevsky, N. S.; Rudashevsky, V. N.; Nielsen, T. F. D.

    2015-12-01

    Copper-palladium intermetallic compounds and alloys (2314 grains) from the Au-Pd ore of the Skaergaard layered gabbroic pluton have been studied. Skaergaardite PdCu, nielsenite PdCu3, (Cu,Pd)β, (Cu,Pd)α, (Pd,Cu,Au,Pt) alloys, and native palladium have been identified as a result of 1680 microprobe analyses. The average compositions and various chemical varieties of these minerals are characterized, as well as vertical and lateral zoning in distribution of noble metals. The primary Pd-Cu alloys were formed within a wide temperature interval broadly synchronously with cooling and crystallization of host gabbro and in close association with separation of Fe-Cu sulfide liquid. In the course of crystallization of residual gabbroic melt enriched in iron, noble and heavy metals and saturated with the supercritical aqueous fluid, PGE and Au are selectively concentrated in the Fe-Cu sulfide phase as Pd-Cu and Cu-Au alloys.

  10. Gallium sulfide and indium sulfide nanoparticles from complex precursors: Synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, D.P. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)]. E-mail: duttadimple@yahoo.co.in; Sharma, G. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kulshreshtha, S.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2007-03-15

    Nanocrystalline gallium sulfide (Ga{sub 2}S{sub 3}) and indium sulfide (In{sub 2}S{sub 3}) have been prepared by a two-step process. The first step involves metathesis reaction of trimethyl gallium/indium ether adduct (Me{sub 3}Ga/In.OEt{sub 2}) with 1,2-ethanedithiol (HSCH{sub 2}CH{sub 2}SH) resulting in the formation of a polymeric precursor. The precursor complex has been characterized using Ga/In analysis, IR, proton NMR and mass spectroscopy. The thermal behavior of both complexes has been studied using thermogravimetric (TG) analysis. In the second step, these precursor complexes have been pyrolysed in furnace under flowing nitrogen atmosphere whereupon they undergo thermodestruction to yield nanometer-sized particles of gallium/indium sulfide. The nanoparticles obtained were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDS). The average size of the nanoparticles ranged from 10 to 12 nm for Ga{sub 2}S{sub 3} and 20 to 22 nm for In{sub 2}S{sub 3}, respectively. This is the first report on use of a binary single source precursor to synthesize {beta}-Ga{sub 2}S{sub 3} nanoparticles.

  11. Production of ultrahigh purity copper using waste copper nitrate solution.

    Science.gov (United States)

    Choi, J Y; Kim, D S

    2003-04-25

    The production of ultrahigh purity copper (99.9999%) by electrolysis in the presence of a cementation barrier has been attempted employing a waste nitric copper etching solution as the electrolyte. The amount of copper deposited on the cathode increased almost linearly with electrolysis time and the purity of copper was observed to increase as the electrolyte concentration was increased. At some point, however, as the electrolyte concentration increased, the purity of copper decreased slightly. As the total surface area of cementation barrier increased, the purity of product increased. The electrolyte temperature should be maintained below 35 degrees C in the range of investigated electrolysis conditions to obtain the ultrahigh purity copper. Considering that several industrial waste solutions contain valuable metallic components the result of present study may support a claim that electrowinning is a very desirable process for their treatment and recovery.

  12. Recovering indium with sulfating roasting from copper-smelting ash

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A technology for recovering indium from Jinchuan copper-smelting ash was developed. Indium in the ash was first enriched to the leaching-slag in leaching process, and then recovered by sulfating roasting. The method included mixing the leaching-slag with sulfuric acid, making them into particles, roasting the mixture, and then leaching the calcine with hot water. Above 90% of indium in calcine could be dissolved into the leaching solution. The optimized conditions were determined as follows: the mass ratio of sulfuric acid to leaching slag was 0.1, the roasting time was about 1 to 1.5 h in the temperature range of 200-250 ℃, and the calcine was leached for 1 h with 5:1 of liquid/solid ratio at 60℃. Over 99% of indium in leaching solution was finally enriched by Zn substitution or sulfide precipitation.

  13. Signaling of hydrogen sulfide and polysulfides.

    Science.gov (United States)

    Kimura, Hideo

    2015-02-10

    It has been almost two decades since the first demonstration of hydrogen sulfide (H2S) as a physiological mediator of cognitive function and vascular tone. H2S is physiologically important because it protects various organs from ischemia-reperfusion injury besides regulating inflammation, oxygen sensing, cell growth, and senescence. The production, metabolism, and regulation of H2S have been studied extensively. H2S modulates target proteins through sulfhydration (or sulfuration) or by the reduction of cysteine disulfide bonds. A large number of novel H2S-donating compounds are being developed owing to the therapeutic potential of H2S. Recently, polysulfides, rather than H2S, have been identified as molecules that sulfhydrate (or sulfurate) their target proteins.

  14. Structure of 4-methylpyridinium Hydrogen Sulfide

    Science.gov (United States)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Martuch, Robert A.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    4-Methylpyridinium hydrogen sulfide, (C6H7NH)HS, M(sub r) = 127.21, consists of C6H7NH(+) cations and HS(-) anions. Z = 2 for the crystal with monoclinic space group Cm (#8), dimensions of a = 8.679(2) A, b = 7.964(1) A, and c = 4.860(2) A, an angle beta of 101.10(2) degrees, and a volume of V = 329.6(3) A(exp 3). R = 0.039 and R(sub w) = 0.048 for 385 reflections with F(sub o)(exp 2) greater than 3 sigma(F(sub o)(exp 2)) and 59 variables. Both the C6H7NH(+) cation and the HS(-) anion lie on crystallographic mirror planes with the N,S, two carbon atoms, and two hydrogen atoms positioned in the planes. The hydrogen atom of the HS(-) anion was not located.

  15. Hydrogen sulfide in a circumstellar envelope

    Science.gov (United States)

    Ukita, N.; Morris, M.

    1983-01-01

    A search for hydrogen sulfide in the cool circumstellar envelopes of 25 stars was made using the 1(10)-1(01) rotational line at 1.8 mm. It was detected in the bipolar nebula/OH maser OH231.8+4.2, an object having a high rate of mass loss. An approximate analysis indicates that 1/60 of the sulfur in this outflowing envelope is in the form of H2S, a fraction which may be similar to that in the atmosphere of the central star. In addition, the shape of the observed line profile is discussed in terms of a possible variation of the outflow velocity with latitude above the system's equatorial plane.

  16. Hydrogen sulfide in gastrointestinal and liver physiopathology.

    Science.gov (United States)

    Cipriani, Sabrina; Mencarelli, Andrea

    2011-04-01

    Hydrogen sulfide (H(2)S) is a gas that can be formed by the action of two enzymes, cystathionine gamma lyase (CSE) and cystathionine beta synthase (CBS). H(2)S has been known for hundreds of years for its poisoning effect, however the idea that H(2)S is not only a poison, but can exert a physiological role in mammalian organisms, originates from the evidence that this gaseous mediator is produced endogenously. In addition to H(2)S synthesis by gastrointestinal tissue, the intestinal mucosa, particularly in the large intestine, is regularly exposed to high concentrations of H(2)S that are generated by some species of bacteria and through the reduction of unabsorbed intestinal inorganic sulphate. This review reports on the effects of H(2)S in the gastrointestinal tract and liver and provides information on the therapeutic applications of H(2)S-donating drugs.

  17. Modulation of hydrogen sulfide by vascular hypoxia

    Directory of Open Access Journals (Sweden)

    Osmond JM

    2014-08-01

    Full Text Available Jessica M Osmond, Nancy L KanagyVascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USAAbstract: Hydrogen sulfide (H2S has emerged as a key regulator of cardiovascular function. This gasotransmitter is produced in the vasculature and is involved in numerous processes that promote vascular homeostasis, including vasodilation and endothelial cell proliferation. Although H2S plays a role under physiological conditions, it has become clear in recent years that hypoxia modulates the production and action of H2S. Furthermore, there is growing evidence that H2S is cytoprotective in the face of hypoxic insults. This review focuses on the synthesis and signaling of H2S in hypoxic conditions in the vasculature, and highlights recent studies providing evidence that H2S is a potential therapy for preventing tissue damage in hypoxic conditions.Keywords: H2S, cystathionine γ-lyase, vascular smooth muscle, endothelium

  18. Tongling:Copper Industry Giant Takes Shape

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>Centering on the strategic goal of building "World Copper Capital", Tongling constantly extends its product lines and improves the copper industry chain. Now, the copper industry with a production value of RMB 100 billion has taken shape.As the largest copper wire rod manufacturer in Asia, Tongling Quanwei Copper Technologies Co., Ltd., upon its moving into the local market,

  19. Effect of radiation on wettability and floatability of sulfide minerals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The feasibility for modifying the wettability and floatability of sulfide minerals by electron beam irradiation has been studied experimentally. The wettability of crystalline pyrite and floatability of some sulfide as pyrite, arsenopyrite, chalcopyrite and marmatite after irradiation were examined by flotation in a modified Hallimond tube. Experimental results show that the hydrophobicity of crystalline pyrite enhances with the increase of irradiation dose in a low dose range. And the flotation responses of sulfide minerals on irradiation dosevary with the mineral species and particle size. The floatability of minerals can be regulated by altering irradiation dose. An explanationfor the mechanism has been suggested based on the principle of radiation chemistry.

  20. Sulfide capacities of MnO-SiO2 slags

    Science.gov (United States)

    Reddy, Ramana G.; Blander, Milton

    1989-04-01

    Sulfide capacities of binary MnO-SiO2 slags at 1773 and 1923 K were calculated thermodynamically. Only known data, such as the standard free energy of formation of MnO and MnS and activities of MnO in the melt, are used in making calculations based on fundamental concepts. Excellent agreement is found between our calculations and published experimental data. Correlations of sulfide capacities, based on optical basicity using Pauling electronegativities or empirically deduced optical basicities, differ from the experimental data in both magnitude and concentration dependence. Our method provides useful predictions of sulfide capacities a priori.

  1. Nanomaterials for the Selective Detection of Hydrogen Sulfide in Air

    Science.gov (United States)

    Llobet, Eduard; Brunet, Jérôme; Pauly, Alain; Ndiaye, Amadou; Varenne, Christelle

    2017-01-01

    This paper presents a focused review on the nanomaterials and associated transduction schemes that have been developed for the selective detection of hydrogen sulfide. It presents a quite comprehensive overview of the latest developments, briefly discusses the hydrogen sulfide detection mechanisms, identifying the reasons for the selectivity (or lack of) observed experimentally. It critically reviews performance, shortcomings, and identifies missing or overlooked important aspects. It identifies the most mature/promising materials and approaches for achieving inexpensive hydrogen sulfide sensors that could be employed in widespread, miniaturized, and inexpensive detectors and, suggests what research should be undertaken for ensuring that requirements are met. PMID:28218674

  2. Micellar-mediated extractive spectrophotometric determination of hydrogen sulfide/sulfide through Prussian Blue reaction: application to environmental samples.

    Science.gov (United States)

    Pandurangappa, Malingappa; Samrat, Devaramani

    2010-01-01

    A sensitive surfactant-mediated extractive spectrophotometric method has been developed, based on the reaction of ferric iron with sulfide to form ferrous iron and its subsequent reaction with ferricyanide to form Prussian Blue, to quantify trace levels of hydrogen sulfide/sulfide in environmental samples. The method obeys Beer's law in the concentration range 2-10 microg of sulfide in 25 mL of aqueous phase with molar absorptivity (epsilon) of 3.92 x 10(4) L mol(-1) cm(-1). The colored species has been extracted into isoamyl acetate in the presence of a cationic surfactant i.e. cetylpyridinium chloride, to enhance the sensitivity of the method with epsilon value 5.2 x 10(4) L mol(-1) cm(-1). The relative standard deviation has been found to be 0.69% for 10 determinations at 4 microg of sulfide and the limit of detection was 0.009 microg mL(-1). The interference from common anions and cations has been studied. The proposed method has been applied to the determination of residual hydrogen sulfide in the laboratory fume hood as well as ambient atmospheric hydrogen sulfide in the vicinity of open sewer lines after fixing the analyte in ionic form using suitable trapping medium.

  3. Micro-aeration for hydrogen sulfide removal from biogas

    Science.gov (United States)

    Duangmanee, Thanapong

    The presence of sulfur compounds (e.g. protein, sulfate, thiosulfate, sulfite, etc.) in the feed stream generates highly corrosive and odorous hydrogen sulfide during anaerobic digestion. The high sulfide level in the biogas stream is not only poisonous to many novel metal catalysts employed in thermo-catalytic processes but also reduces the quality of methane to produce renewable energy. This study used an innovative, low-maintenance, low-cost biological sulfide removal technology to remove sulfides simultaneously from both gas and liquid phase. ORP (Oxidation-Reduction-Potential) was used as the controlling parameter to precisely regulate air injection to the sulfide oxidizing unit (SOU). The microaeration technique provided just enough oxygen to partially oxidize sulfides to elemental sulfur without inhibiting methanogenesis. The SOU was equipped with a diffuser at the bottom for the dispersion of sulfide-laden biogas and injected air throughout the column. The SOU can be operated as a standalone unit or coupled with an anaerobic digester to simultaneously remove sulfide from the biogas and effluent. The integrated system was capable of reducing hydrogen sulfide in biogas from 2,450 to less than 2 ppmV with minimal sulfate production at the highest available sulfide loading rate of 0.24 kg/m3-day. More than 98% of sulfide removed was recovered as elemental sulfur. However, the standalone SOU was able to operate at high hydrogen sulfide loading of 1.46 kg/m 3-day at inlet sulfide concentration of 3000 ppmV and reduce the off-gas hydrogen sulfide concentrations to less than 10 ppmV. The experiment also revealed that the ORP controlled aeration was sensitive enough to prevent oxygen overdosing (dampening effect) during unexpected surges of aeration. Using generalized linear regression, a model predicting output H2S concentration based on input H2S concentrations, SOU medium heights, and biogas flow rates, was derived. With 95% confidence, output H2S concentration

  4. The partitioning of copper among selected phases of geologic media of two porphyry copper districts, Puerto Rico

    Science.gov (United States)

    Learned, R.E.; Chao, T.T.; Sanzolone, R.F.

    1981-01-01

    In experiments designed to determine the manner in which copper is partitioned among selected phases that constitute geologic media, we have applied the five-step sequential extraction procedure of Chao and Theobald to the analysis of drill core, soils, and stream sediments of the Rio Vivi and Rio Tanama porphyry copper districts of Puerto Rico. The extraction procedure affords a convenient means of determining the trace-metal content of the following fractions: (1) Mn oxides and "reactive" Fe oxides; (2) "amorphous" Fe oxides; (3) "crystalline" Fe oxides; (4) sulfides and magnetite; and (5) silicates. An additional extraction between steps (1) and (2) was performed to determine organic-related copper in stream sediments. The experimental results indicate that apportionment of copper among phases constituting geologic media is a function of geochemical environment. Distinctive partitioning patterns were derived from the analysis of drill core from each of three geochemical zones: (a) the supergene zone of oxidation; (b) the supergene zone of enrichment; and (c) the hypogene zone; and similarly, from the analysis of; (d) soils on a weakly leached capping; (e) soils on a strongly leached capping; and (f) active stream sediment. The experimental results also show that geochemical contrasts (anomaly-to-background ratios) vary widely among the five fractions of each sampling medium investigated, and that at least one fraction of each medium provides substantially stronger contrast than does the bulk medium. Fraction (1) provides optimal contrast for stream sediments of the district; fraction (2) provides optimal contrast for soils on a weakly leached capping; fraction (3) provides optimal contrast for soils on a strongly leached capping. Selective extraction procedures appear to have important applications to the orientation and interpretive stages of geochemical exploration. Further investigation and testing of a similar nature are recommended. ?? 1981.

  5. Magmatic-vapor expansion and the formation of high-sulfidation gold deposits: Structural controls on hydrothermal alteration and ore mineralization

    Science.gov (United States)

    Berger, B.R.; Henley, R.W.

    2011-01-01

    High-sulfidation copper-gold lode deposits such as Chinkuashih, Taiwan, Lepanto, Philippines, and Goldfield, Nevada, formed within 1500. m of the paleosurface in volcanic terranes. All underwent an early stage of extensive advanced argillic silica-alunite alteration followed by an abrupt change to spatially much more restricted stages of fracture-controlled sulfide-sulfosalt mineral assemblages and gold-silver mineralization. The alteration as well as ore mineralization stages of these deposits were controlled by the dynamics and history of syn-hydrothermal faulting. At the Sulfate Stage, aggressive advanced argillic alteration and silicification were consequent on the in situ formation of acidic condensate from magmatic vapor as it expanded through secondary fracture networks alongside active faults. The reduction of permeability at this stage due to alteration decreased fluid flow to the surface, and progressively developed a barrier between magmatic-vapor expansion constrained by the active faults and peripheral hydrothermal activity dominated by hot-water flow. In conjunction with the increased rock strength resulting from alteration, subsequent fault-slip inversion in response to an increase in compressional stress generated new, highly permeable fractures localized by the embrittled, altered rock. The new fractures focused magmatic-vapor expansion with much lower heat loss so that condensation occurred. Sulfide Stage sulfosalt, sulfide, and gold-silver deposition then resulted from destabilization of vapor phase metal species due to vapor decompression through the new fracture array. The switch from sulfate to sulfide assemblages is, therefore, a logical consequence of changes in structural permeability due to the coupling of alteration and fracture dynamics rather than to changes in the chemistry of the fluid phase at its magmatic source. ?? 2010.

  6. An Experiment in Autotrophic Fermentation: Microbial Oxidation of Hydrogen Sulfide.

    Science.gov (United States)

    Sublette, Kerry L.

    1989-01-01

    Described is an experiment which uses an autotrophic bacterium to anaerobically oxidize hydrogen sulfide to sulfate in a batch-stirred tank reactor. Discusses background information, experimental procedure, and sample results of this activity. (CW)

  7. Hydrogen Sulfide Micro-Sensor for Biomass Fouling Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hydrogen Sulfide (H2S)is the leading chemical agent causing human fatalities following inhalation exposures. The overall aim of this project is to develop and...

  8. Nanostructured Metal Oxides and Sulfides for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Liu, Xue; Huang, Jia-Qi; Zhang, Qiang; Mai, Liqiang

    2017-02-03

    Lithium-sulfur (Li-S) batteries with high energy density and long cycle life are considered to be one of the most promising next-generation energy-storage systems beyond routine lithium-ion batteries. Various approaches have been proposed to break down technical barriers in Li-S battery systems. The use of nanostructured metal oxides and sulfides for high sulfur utilization and long life span of Li-S batteries is reviewed here. The relationships between the intrinsic properties of metal oxide/sulfide hosts and electrochemical performances of Li-S batteries are discussed. Nanostructured metal oxides/sulfides hosts used in solid sulfur cathodes, separators/interlayers, lithium-metal-anode protection, and lithium polysulfides batteries are discussed respectively. Prospects for the future developments of Li-S batteries with nanostructured metal oxides/sulfides are also discussed.

  9. Selective adsorption of bacteria on sulfide minerals surface

    Institute of Scientific and Technical Information of China (English)

    JIA Chun-yun; WEI De-zhou; LIU Wen-gang; HAN Cong; GAO Shu-ling; WANG Yu-juan

    2008-01-01

    The adsorption of bacteria on sulfide minerals surface was studied, and the selective adsorption mechanism of cells on the sulfide minerals was investigated by means of FTIR, UVS and XPS. The results show that the three strains of bacteria adsorbed more preferentially on pyrite than on other two sulfide minerals surface at neutral and alkaline pH conditions. FTIR and UVS of three strains of bacteria indicate that there are more functional groups on their surface, such as O-H, C=O, N-H, C-O, and the content of saccharide is more than that of protein. The state of every element on sulfide minerals surface was analyzed by XPS. The empty orbital number of electronic shell of metal ions on minerals surface is important in selective adsorption process, and some stable constants of metal coordinates can be used to explain the contribution of some groups in saccharide of cell wall to the selective adsorption.

  10. Oxidation and Precipitation of Sulfide in Sewer Networks

    DEFF Research Database (Denmark)

    Nielsen, A. H.

    wastewater and biofilms of sewer networks was studied in detail with emphasis on determination of process kinetics and stoichiometry. In the water phase, sulfide oxidation may be both chemical and biological and the investigations showed that both processes were of significant importance in the sulfur cycle...... transformations. The experiments indicated that biological sulfide oxidation in the water phase and sulfide oxidation by sewer biofilms produce elemental sulfur under the conditions investigated. The stoichiometry of chemical sulfide oxidation was apparently more complex producing both thiosulfate and sulfate......-workers at Aalborg University for more than a decade. In the basic version, the WATS model simulates changes in dissolved oxygen (DO) and organic fractions of different biodegradability under both aerobic and anaerobic conditions. Evaluation of the model concept has demonstrated that it can be successfully...

  11. Optimization of biological sulfide removal in a CSTR bioreactor.

    Science.gov (United States)

    Roosta, Aliakbar; Jahanmiri, Abdolhossein; Mowla, Dariush; Niazi, Ali; Sotoodeh, Hamidreza

    2012-08-01

    In this study, biological sulfide removal from natural gas in a continuous bioreactor is investigated for estimation of the optimal operational parameters. According to the carried out reactions, sulfide can be converted to elemental sulfur, sulfate, thiosulfate, and polysulfide, of which elemental sulfur is the desired product. A mathematical model is developed and was used for investigation of the effect of various parameters on elemental sulfur selectivity. The results of the simulation show that elemental sulfur selectivity is a function of dissolved oxygen, sulfide load, pH, and concentration of bacteria. Optimal parameter values are calculated for maximum elemental sulfur selectivity by using genetic algorithm as an adaptive heuristic search. In the optimal conditions, 87.76% of sulfide loaded to the bioreactor is converted to elemental sulfur.

  12. Mechanochemical reactions on copper-based compounds

    NARCIS (Netherlands)

    Castricum, H.L.; Bakker, H.; Poels, E.K.

    1999-01-01

    Mechanochemical reactions of copper and copper oxides with oxygen and carbon dioxide are discussed, as well as decomposition and reduction of copper compounds by mechanical milling under high-vacuum conditions.

  13. Oxidation Mechanism of Copper Selenide

    Science.gov (United States)

    Taskinen, Pekka; Patana, Sonja; Kobylin, Petri; Latostenmaa, Petri

    2014-09-01

    The oxidation mechanism of copper selenide was investigated at deselenization temperatures of copper refining anode slimes. The isothermal roasting of synthetic, massive copper selenide in flowing oxygen and oxygen - 20% sulfur dioxide mixtures at 450-550 °C indicate that in both atmospheres the mass of Cu2Se increases as a function of time, due to formation of copper selenite as an intermediate product. Copper selenide oxidises to copper oxides without formation of thick copper selenite scales, and a significant fraction of selenium is vaporized as SeO2(g). The oxidation product scales on Cu2Se are porous which allows transport of atmospheric oxygen to the reaction zone and selenium dioxide vapor to the surrounding gas. Predominance area diagrams of the copper-selenium system, constructed for selenium roasting conditions, indicate that the stable phase of copper in a selenium roaster gas with SO2 is the sulfate CuSO4. The cuprous oxide formed in decomposition of Cu2Se is further sulfated to CuSO4.

  14. Copper and copper-nickel-alloys - An overview

    Energy Technology Data Exchange (ETDEWEB)

    Klassert, Anton; Tikana, Ladji [Deutsches Kupferinstitut e.V. Am Bonneshof 5, 40474 Duesseldorf (Germany)

    2004-07-01

    With the increasing level of industrialization the demand for and the number of copper alloys rose in an uninterrupted way. Today, the copper alloys take an important position amongst metallic materials due to the large variety of their technological properties and applications. Nowadays there exist over 3.000 standardized alloys. Copper takes the third place of all metals with a worldwide consumption of over 15 millions tons per year, following only to steel and aluminum. In a modern industrial society we meet copper in all ranges of the life (electro-technology, building and construction industry, mechanical engineering, automotive, chemistry, offshore, marine engineering, medical applications and others.). Copper is the first metal customized by humanity. Its name is attributed to the island Cyprus, which supplied in the antiquity copper to Greece, Rome and the other Mediterranean countries. The Romans called it 'ore from Cyprus' (aes cyprium), later cuprum. Copper deposited occasionally also dapper and could be processed in the recent stone age simply by hammering. Already in early historical time copper alloys with 20 to 50 percent tin was used for the production of mirrors because of their high reflecting power. Although the elementary nickel is an element discovered only recently from a historical perspective, its application in alloys - without any knowledge of the alloy composition - occurred at least throughout the last 2.000 years. The oldest copper-nickel coin originates from the time around 235 B.C.. Only around 1800 AD nickel was isolated as a metallic element. In particular in the sea and offshore technology copper nickel alloys found a broad field of applications in piping systems and for valves and armatures. The excellent combination of characteristics like corrosion resistance, erosion stability and bio-fouling resistance with excellent mechanical strength are at the basis of this success. An experience of many decades supports the use

  15. [Leaching of copper ore of the Udokanskoe deposit at low temperatures by an association of acidophilic chemolithotrophic microorganisms].

    Science.gov (United States)

    Kondrat'eva, T F; Pivovarova, T A; Krylova, L N; Melamud, V S; Adamov, E V; Karavaĭko, G I

    2011-01-01

    Pure cultures of indigenous microorganisms Acidithiobacillus ferrooxidans strain TFUd, Leptospirillum ferrooxidans strain LUd, and Sulfobacillus thermotolerans strain SUd have been isolated from the oxidation zone of sulfide copper ore of the Udokanskoe deposit. Regimes of bacterial-chemical leaching of ore have been studied over a temperature range from -10 to +20 degrees C. Effects of pH, temperature, and the presence of microorganisms on the extraction of copper have been shown. Bacterial leaching has been detected only at positive values of temperature, and has been much more active at +20 than at +4 degrees C. The process of leaching was more active when the ore contained more hydrophilic and oxidized minerals. The possibility of copper ore leaching of the Udokanskoe deposit using sulfuric acid with pH 0.4 at negative values of temperature and applying acidophilic chemolithotrophic microorganisms at positive values of temperature and low pH values was shown.

  16. Mineralogy and fluid inclusion studies in kalchoye Copper- gold deposit, East of Esfahan

    Directory of Open Access Journals (Sweden)

    Rezvan Mehvary

    2009-09-01

    Full Text Available Kalchoye Copper-gold deposit is located about 110 kilometers east of Esfahan province and within the Eocene volcano sedimentary rocks. Sandy tuff and andesite lava are important members of this complex.The form of mineralization in area is vein and veinlet and quartz as the main gangue phase. The main ore minerals are chalcopyrite, chalcocite, galena and weathered minerals such as goethite, iron oxides, malachite and azurite. Studies in area indicate that ore mineralization Kalchoye is low sulfide, quartz type of hydrothermal ore deposits and results of thermometry studies on quartz minerals low- medium fluid with low potential mineralization is responsible for mineralization in this area.

  17. An eco-friendly oxidation of sulfide compounds

    Indian Academy of Sciences (India)

    RAVINDRA B WAGH; SITARAM H GUND; JAYASHREE M NAGARKAR

    2016-08-01

    An improved green route has been developed for the oxidation of sulfide compounds. Albendazole is converted to ricobendazole or albendazole sulfone using H₂O₂ as an oxidant and H₂O as the solvent. High yields of the corresponding products were obtained by carrying out the reaction at room temperature. This synthetic method is environmentally clean and safe, operationally simple for the oxidation of other benzimidazole anthelmintics and various sulfide compounds.

  18. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  19. LUMINESCENCE OF CADMIUM SULFIDE QUANTUM DOTS IN FLUOROPHOSPHATE GLASSES

    OpenAIRE

    Z. O. Lipatova; E. V. Kolobkova; V. A. Aseev

    2015-01-01

    Cadmium sulfide quantum dots are perspective materials in optics, medicine, biology and optoelectronics. Fluorophosphate glasses, doped with cadmium sulfide quantum dots, were examined in the paper. Heat treatment led to the formation of quantum dots with diameters equal to 2.8 nm, 3.0 nm and 3.8 nm. In view of such changes in the quantum dots size the fundamental absorption edge shift and the luminescence band are being displaced to the long wavelengths. Luminescence lifetime has been fou...

  20. Bioavailability and Methylation Potential of Mercury Sulfides in Sediments

    Science.gov (United States)

    2014-08-01

    the aquatic environment is a critical step towards accumulation of this toxic metal in the aquatic food chain. MeHg is produced in the environment...much more abundant than mercury (e.g. iron, aluminum, manganese , titanium, zinc). Nanoparticles and polynuclear clusters of metal sulfides such as...trace metal bioavailability and toxicity has yet to be fully realized. Our findings provide a new approach that may be applied to other metal-sulfide

  1. Potential for improved extraction of tellurium as a byproduct of current copper mining processes

    Science.gov (United States)

    Hayes, S. M.; Spaleta, K. J.; Skidmore, A. E.

    2016-12-01

    Tellurium (Te) is classified as a critical element due to its increasing use in high technology applications, low average crustal abundance (3 μg kg-1), and primary source as a byproduct of copper extraction. Although Te can be readily recovered from copper processing, previous studies have estimated a 4 percent extraction efficiency, and few studies have addressed Te behavior during the entire copper extraction process. The goals of the present study are to perform a mass balance examining Te behavior during copper extraction and to connect these observations with mineralogy of Te-bearing phases which are essential first steps in devising ways to optimize Te recovery. Our preliminary mass balance results indicate that less than 3 percent of Te present in copper ore is recovered, with particularly high losses during initial concentration of copper ore minerals by flotation. Tellurium is present in the ore in telluride minerals (e.g., Bi-Te-S phases, altaite, and Ag-S-Se-Te phases identified using electron microprobe) with limited substitution into sulfide minerals (possibly 10 mg kg-1 Te in bulk pyrite and chalcopyrite). This work has also identified Te accumulation in solid-phase intermediate extraction products that could be further processed to recover Te, including smelter dusts (158 mg kg-1) and pressed anode slimes (2.7 percent by mass). In both the smelter dusts and anode slimes, X-ray absorption spectroscopy indicates that about two thirds of the Te is present as reduced tellurides. In anode slimes, electron microscopy shows that the remaining Te is present in an oxidized form in a complex Te-bearing oxidate phase also containing Pb, Cu, Ag, As, Sb, and S. These results clearly indicate that more efficient, increased recovery of Te may be possible, likely at minimal expense from operating copper processing operations, thereby providing more Te for manufacturing of products such as inexpensive high-efficiency solar panels.

  2. Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients

    Science.gov (United States)

    Balter, Vincent; Nogueira da Costa, Andre; Paky Bondanese, Victor; Jaouen, Klervia; Lamboux, Aline; Sangrajrang, Suleeporn; Vincent, Nicolas; Fourel, François; Télouk, Philippe; Gigou, Michelle; Lécuyer, Christophe; Srivatanakul, Petcharin; Bréchot, Christian; Albarède, Francis; Hainaut, Pierre

    2015-01-01

    The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper (65Cu/63Cu) and sulfur (34S/32S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is 63Cu-enriched by ∼0.4‰ and sulfur is 32S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The 32S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.

  3. Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients.

    Science.gov (United States)

    Balter, Vincent; Nogueira da Costa, Andre; Bondanese, Victor Paky; Jaouen, Klervia; Lamboux, Aline; Sangrajrang, Suleeporn; Vincent, Nicolas; Fourel, François; Télouk, Philippe; Gigou, Michelle; Lécuyer, Christophe; Srivatanakul, Petcharin; Bréchot, Christian; Albarède, Francis; Hainaut, Pierre

    2015-01-27

    The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper ((65)Cu/(63)Cu) and sulfur ((34)S/(32)S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is (63)Cu-enriched by ∼0.4‰ and sulfur is (32)S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The (32)S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.

  4. Variations of serum copper values in pregnancy

    OpenAIRE

    Vukelić Jelka; Kapamadžija Aleksandra; Petrović Đorđe; Grujić Zorica; Novakov-Mikić Aleksandra; Kopitović Vesna; Bjelica Artur

    2012-01-01

    Introduction. Copper is essential micronutrient and has an important role in the human body. The serum copper increases during pregnancy and is doubled at full term. Lower levels of serum copper in pregnancy are connected with some pathological conditions. Objective. The aim of this study was to estimate the levels of serum copper in normal and pathological pregnancies, comparing them with values of serum copper in non-pregnant women, to determine if serum copper is lower in some pathol...

  5. Sulfide capacity of high alumina blast furnace slags

    Science.gov (United States)

    Shankar, Amitabh; Görnerup, Märten; Seetharaman, S.; Lahiri, A. K.

    2006-12-01

    Sulfide capacities of high alumina blast furnace slags were experimentally determined using the gas-slag equilibration technique. Two different slag systems were considered for the current study, namely, CaO-SiO2-MgO-Al2O3 quaternary and CaO-SiO2-MgO-Al2O3-TiO2 quinary system. The liquid slag was equilibrated with the Ar-CO-CO2-SO2 gas mixture. Experiments were conducted in the temperature range of 1773 to 1873 K. The effects of temperature, basicity, and the MgO and TiO2 contents of slags on sulfide capacity were studied. As expected, sulfide capacity was found to increase with the increase in temperature and basicity. At the higher experimental temperature, titania decreases the sulfide capacity of slag. However, at the lower temperature, there was no significant effect of titania on the sulfide capacity of slag. Sulfide capacity increases with the increase in MgO content of slag if the MgO content is more than 5 pct.

  6. Sulfide oxidation in fluidized bed bioreactor using nylon support material

    Institute of Scientific and Technical Information of China (English)

    Varsha Midha; M K Jha; Apurba Dey

    2012-01-01

    A continuous fluidized bed bioreactor(FBBR)with nylon support particles was used to treat synthetic sulfide wastewater at different hydraulic retention time of 25,50 and 75 min and upflow velocity of 14,17 and 20 m/hr.The effects of upflow velocity,hydraulic retention time and reactor operation time on sulfide oxidation rate were studied using statistical model.Mixed culture obtained from the activated sludge,taken from tannery effluent treatment plant,was used as a source for microorganisms.The diameter and density of the nylon particles were 2-3 mm and 1140 kg/m3,respectively.Experiments were carried out in the reactor at a temperature of(30± 2)℃,at a fixed bed height of 16 cm after the formation of biofilm on the surface of support particles.Biofilm thickness reached(42±3)μm after 15 days from reactor start-up.The sulfide oxidation,sulfate and sulfur formation is examined at all hydraulic retention times and upflow velocities.The results indicated that almost 90%-92% sulfide oxidation was achieved at all hydraulic retention times.Statistical model could explain 94% of the variability and analysis of variance showed that upflow velocity and hydraulic retention time slightly affected the sulfide oxidation rate.The highest sulfide oxidation of 92% with 70% sulfur was obtained at hydraulic retention time of 75 min and upflow velocity of 14 m/hr.

  7. Sulfide oxidation in fluidized bed bioreactor using nylon support material.

    Science.gov (United States)

    Midha, Varsha; Jha, M K; Dey, Apurba

    2012-01-01

    A continuous fluidized bed bioreactor (FBBR) with nylon support particles was used to treat synthetic sulfide wastewater at different hydraulic retention time of 25, 50 and 75 min and upflow velocity of 14, 17 and 20 m/hr. The effects of upflow velocity, hydraulic retention time and reactor operation time on sulfide oxidation rate were studied using statistical model. Mixed culture obtained from the activated sludge, taken from tannery effluent treatment plant, was used as a source for microorganisms. The diameter and density of the nylon particles were 2-3 mm and 1140 kg/m3, respectively. Experiments were carried out in the reactor at a temperature of (30 +/- 2) degrees C, at a fixed bed height of 16 cm after the formation of biofilm on the surface of support particles. Biofilm thickness reached (42 +/- 3) microm after 15 days from reactor start-up. The sulfide oxidation, sulfate and sulfur formation is examined at all hydraulic retention times and upflow velocities. The results indicated that almost 90%-92% sulfide oxidation was achieved at all hydraulic retention times. Statistical model could explain 94% of the variability and analysis of variance showed that upflow velocity and hydraulic retention time slightly affected the sulfide oxidation rate. The highest sulfide oxidation of 92% with 70% sulfur was obtained at hydraulic retention time of 75 min and upflow velocity of 14 m/hr.

  8. Challenges for rescuing drill core from volcanogenic massive sulfide deposits in northern Wisconsin

    Science.gov (United States)

    Stanley, V.; Schoephoester, P.; Lodge, R. W. D.

    2016-12-01

    Providing adequate physical care for unique lithologies can be a challenge for rock core repositories. The purpose of a repository is to preserve its collections such that they will be available and useful for current and future research. Preservation requires both documentation and physical care, including the state of the facility housing the collections, as specimens can be endangered by environmental factors. Digital documentation is a crucial first step in rescuing at-risk samples as it allows the collection to be monitored through time. Exploratory drill core from the Flambeau copper-gold mine in Ladysmith, WI was donated to the Wisconsin Geological and Natural History Survey (WGNHS). The collection includes over 4.7 km of irreplaceable core from 50 sites. The ore body is situated in the Ladysmith-Rhinelander Volcanic Complex, an Early Proterozoic greenstone belt that hosts at least 13 volcanogenic massive sulfide deposits (DeMatties, 1996), including Flambeau. Mineral assemblages include up to 50% sulfide minerals, mainly pyrite and marcasite (May and Dinkowitz, 1996). These lithologies present a unique preservation challenge - storage conditions must be temperature and humidity controlled to prevent pyrite oxidation (Newman 1998), which chemically and physically degrades the samples as well as labels, containers, and shelving. Once initiated, pyrite oxidation cannot be stopped or reversed, but may be stabilized (Howie, 1992). Although protecting these materials is a vital part of the WGNHS mission, climate-control modifications to the facility are cost-prohibitive. In order to rescue the samples, we documented the collection's present state. We developed and implemented a new database schema including IGSNs to improve metadata records, track samples, and link data. Although preservation of the physical samples remains a challenge, digital workflows and data management improvements will allow WGNHS to monitor the condition of these samples while also

  9. Reduced hydrogen sulfide from crude oil using metal nanoparticles produced by electrochemical deposition

    Directory of Open Access Journals (Sweden)

    Sahar Safarkhani

    2016-06-01

    Full Text Available Hydrogen sulfide is one of the most dangerous contaminants in crude oil and natural gas that must be removed before transport and refining. It has multiple effects on the environment and the industry is bad that these effects include acid rain, cancer, corrosion of pipelines, poison catalytic converters in car exhaust. In this study, to eliminate H2S crude oil Nano emulsion used ionic liquid. Ionic liquids also with metal nanoparticles (MNPs have been modified. Improve and reform the electrochemical deposition of metal salts is done. Ionic liquid 1 - Hydro One Atyl2- methyl imidazolium de cyanimide [HEMIM] [DCA] is inherently hydrophilic as Scavenger H2S was added to the crude oil. Two types of metal salts of Fe (acac 3 and Cu (SO4 electrochemical deposition method for producing metal nanoparticles in the ionic liquid [HEMIM] [DCA] was used. Suitable concentrations of ionic liquids for the complete removal of hydrogen sulfide from crude oil were determined by two methods: static and dynamic methods. Dynamic method to determine the required dose used to remove H2S. Static method using response surface and through statistical experimental design for modeling and assessment CCD H2S was removed parameters. Three factors, namely Scavengerdose, contact time and the reaction temperature were studied. The interaction between these factors on the concentration of H2S in the crude oil was studied. 3 important statistical models for ionic liquids and ionic liquid containing two types of metal nanoparticles were developed. This model has an index of noncompliance was not important. The ionic liquid modified with nanoparticles , activity and H2S removal capacity is significantly increased , to the extent that the effect of one or two major factors were considered too small or unimportant . Copper metal nanoparticles showed better performance for the removal of H2S to iron

  10. Nickel, copper and cobalt coalescence in copper cliff converter slag

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2016-01-01

    Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

  11. Study of Copper Substitute in High Copper Price Market Environment

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>The high price of copper drives up industry cost,also it is difficult for terminal products to raise price to transfer the cost pressure brought by increase in copper price,as a result downstream consumption markets instead try to seek

  12. Fixation Property of Copper Triazole Wood Preservatives

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    According to AWPA E11-2006 standard,copper fixation rates of several copper-based formulations,such as ammoniacal copper,amine copper,and ammoniacal-ethanolamine copper,as well as alkaline copper quaternary(ACQ),were tested and compared in this paper.And the fixation rates of tebuconazole(TEB) and propiconazole(PPZ) in several formulations,such as copper azole,emulsified type and solvent type,were also compared.The determination of copper content in the leachate was analyzed by atomic absorption spectrom...

  13. INTERACTION OF COPPER BASED PRESERVATIVES WITH WOOD

    Directory of Open Access Journals (Sweden)

    Ali Temiz

    2004-11-01

    Full Text Available Copper is highly toxic to fungi and the element is widely used in many preservative formulations over 50 years. The interactions of wood and copper-based preservatives impact both the performance and the environment aspects of treated wood. Copper might be present in treated wood as coppercellulose complex, copper-lignin complex, and crystalline or amorphous inorganic/organic copper compounds. In this review; it was aimed to investigate the interactions of wood and copper-based preservatives, Copper Adsorpsion factors and copper forms in treated wood

  14. Development of novel copper-based sorbents for hot-gas cleanup. Final technical report, September 1, 1991--August 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Hill, A.H.; Wangerow, J.R. [Institute of Gas Technology, Chicago, IL (United States); Flytzani-Stephanopoulos, M.; Bo, Luhong; Patel, C.; Chang, D. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1992-12-31

    The objective of this investigation was to evaluate several novel copper-based binary oxides for their suitability as regenerable sorbents for hot gas cleanup application in the temperature range of 650{degree} to 850{degree}C. To achieve this objective, several novel binary oxides of copper were systematically evaluated and ranked in terms of their high-temperature stability against reduction to metal, sulfidation reactivity, and regenerability. The sorbents studied included oxides of chromium, cerium, aluminum, magnesium, manganese, titanium, iron, and silicon. The results of initial testing indicated that mixed binary oxides of copper with chromium (CuCr{sub 2}O{sub 4}) and cerium (CuO{circle_dot}CeO{sub 2}) were the most promising sorbents for such high temperature gas cleanup applications. These two sorbents were further evaluated in cyclic sulfidation/regeneration tests in 10--15 cycles to determine the effect of operating conditions on their performance. The results of this investigation indicate that the two selected sorbents, copper-chromium and copper-cerium, are capable of removing H{sub 2}S from the hot fuel gas to very low levels (<10 ppmv) at temperatures as high as 850{degree}C with good sorbent regenerability in cyclic process. These sorbents should be further studied to achieve optimum sorbent composition for hot gas cleanup application.

  15. Magnesium-induced copper-catalyzed synthesis of unsymmetrical diaryl chalcogenide compounds from aryl iodide via cleavage of the Se-Se or S-S bond.

    Science.gov (United States)

    Taniguchi, Nobukazu; Onami, Tetsuo

    2004-02-06

    The methodology for a copper-catalyzed preparation of diaryl chalcogenide compounds from aryl iodides and diphenyl dichalcogenide molecules is reported. Unsymmetrical diaryl sulfide or diaryl selenide can be synthesized from aryl iodide and PhYYPh (Y = S, Se) with a copper catalyst (CuI or Cu(2)O) and magnesium metal in one pot. This reaction can be carried out under neutral conditions according to an addition of magnesium metal as the reductive reagent. Furthermore, it is efficiently available for two monophenylchalcogenide groups generated from diphenyl dichalcogenide.

  16. Dihydrogen Activation by Titanium Sulfide Complexes

    Science.gov (United States)

    Sweeney, Zachary K.; Polse, Jennifer L.; Bergman*, Robert G.; Andersen*, Richard A.

    2005-01-01

    The titanocene sulfido complex Cp*2Ti(S)py (1, Cp* = pentamethylcyclopentadienyl; py = pyridine) is synthesized by addition of a suspension of S8 to a toluene solution of Cp*2Ti-(CH2CH2) (2) and py. The rate of rotation of the pyridine ligand in solution was determined by 1H NMR spectroscopy, and the structure of 1 was determined by X-ray crystallography. Complex 1 reacts reversibly with dihydrogen to give Cp*2Ti(H)SH (6) and py. Reaction of 1 with HD gives an equilibrium mixture of Cp*2Ti(D)SH and Cp*2Ti(H)SD; H2 and D2 are not formed in this reaction. 1D 1H NMR magnetization transfer spectra and 2D EXSY 1H NMR spectra of 6 in the presence of H2 show that in solution the H2, hydride, and hydrosulfido hydrogen atoms exchange. A four-center mechanism for this exchange is proposed. The EXSY studies show that the Ti–H and S–H hydrogens exchange with each other more rapidly than either of those hydrogens exchanges with external H2. A transient dihydrogen complex intermediate is proposed to explain this observation. The infrared spectrum of 6 shows an absorption assigned to the Ti–H stretching mode at 1591 cm−1 that shifts upon deuteration to 1154 cm−1. Reaction of 1 with trimethylsilane, diethylsilane, or dimethylsilane gives Cp*2-Ti(H)SSiMe3 (7), Cp*2Ti(H)SSiHEt2 (8), or Cp*2Ti(H)SSiHMe2 (9), respectively. The isotope effect for the reaction producing 7 has been measured, and a mechanism is proposed. Treatment of 1 with an additional equivalent of S8 results in the formation of the disulfide Cp*2Ti(S2) (4). Acetylene inserts into the Ti–S bond of 4 to produce the vinyl disulfide complex 5. The structures of 4 and 5 have been determined by X-ray diffraction. Compound 4 reacts with 2 in the presence of py to produce 1. Phosphines react with 4 in the presence of H2 to provide 6 and the corresponding phosphine sulfide. Reaction of hydrogen with 4 gives Cp*2-Ti(SH)2 (3). The reactions of 1 and 4 with dihydrogen provide a model for possible mechanisms of H2

  17. Electroleaching of Copper Waste with Recovery of Copper by Electrodialysis

    Directory of Open Access Journals (Sweden)

    Nuñez P.

    2013-04-01

    Full Text Available A new process to leach and recover copper from solid waste using electric fields was designed. The leaching with electro migration is presented as an alternative to traditional leaching. Preliminary data indicate that the copper ion migration is facilitated by using the electrical potential difference; therefore applying a potential difference in the processes of leaching facilitates the removal of copper. This is especially useful when mineral concentrations are very low. Different phenomena associated with transport of copper in solution are studied to generate a model able predict the state of the copper ion concentration in time. A kinetic model for the process was developed and fitted very well the experimental data.

  18. Synthesis of copper/copper oxide nanoparticles by solution plasma

    Science.gov (United States)

    Saito, Genki; Hosokai, Sou; Tsubota, Masakatsu; Akiyama, Tomohiro

    2011-07-01

    This paper describes the synthesis of copper/copper oxide nanoparticles via a solution plasma, in which the effect of the electrolyte and electrolysis time on the morphology of the products was mainly examined. In the experiments, a copper wire as a cathode was immersed in an electrolysis solution of a K2CO3 with the concentration from 0.001 to 0.50 M or a citrate buffer (pH = 4.8), and was melted by the local-concentration of current. The results demonstrated that by using the K2CO3 solution, we obtained CuO nanoflowers with many sharp nanorods, the size of which decreased with decreasing the concentration of the solution. Spherical particles of copper with/without pores formed when the citrate buffer was used. The pores in the copper nanoparticles appeared when the applied voltage changed from 105 V to 130 V, due to the dissolution of Cu2O.

  19. Bio-orthogonal "click-and-release" donation of caged carbonyl sulfide (COS) and hydrogen sulfide (H2S).

    Science.gov (United States)

    Steiger, Andrea K; Yang, Yang; Royzen, Maksim; Pluth, Michael D

    2017-01-24

    Hydrogen sulfide (H2S) is an important biomolecule with high therapeutic potential. Here we leverage the inverse-electron demand Diels-Alder (IEDDA) click reaction between a thiocarbamate-functionalized trans-cyclooctene and a tetrazine to deliver carbonyl sulfide (COS), which is quickly converted to H2S by the uniquitous enzyme carbonic anhydrase (CA), thus providing a new strategy for bio-orthogonal COS/H2S donation.

  20. Hydrogen Sulfide--Mechanisms of Toxicity and Development of an Antidote.

    Science.gov (United States)

    Jiang, Jingjing; Chan, Adriano; Ali, Sameh; Saha, Arindam; Haushalter, Kristofer J; Lam, Wai-Ling Macrina; Glasheen, Megan; Parker, James; Brenner, Matthew; Mahon, Sari B; Patel, Hemal H; Ambasudhan, Rajesh; Lipton, Stuart A; Pilz, Renate B; Boss, Gerry R

    2016-02-15

    Hydrogen sulfide is a highly toxic gas-second only to carbon monoxide as a cause of inhalational deaths. Its mechanism of toxicity is only partially known, and no specific therapy exists for sulfide poisoning. We show in several cell types, including human inducible pluripotent stem cell (hiPSC)-derived neurons, that sulfide inhibited complex IV of the mitochondrial respiratory chain and induced apoptosis. Sulfide increased hydroxyl radical production in isolated mouse heart mitochondria and F2-isoprostanes in brains and hearts of mice. The vitamin B12 analog cobinamide reversed the cellular toxicity of sulfide, and rescued Drosophila melanogaster and mice from lethal exposures of hydrogen sulfide gas. Cobinamide worked through two distinct mechanisms: direct reversal of complex IV inhibition and neutralization of sulfide-generated reactive oxygen species. We conclude that sulfide produces a high degree of oxidative stress in cells and tissues, and that cobinamide has promise as a first specific treatment for sulfide poisoning.