Journal articles: 'Copper-gold'

1

Zhu, Zhimin. "Gold in iron oxide copper–gold deposits." Ore Geology Reviews 72 (January 2016): 37–42. http://dx.doi.org/10.1016/j.oregeorev.2015.07.001.

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2

Freeman Gilstrap, Dorothy. "From Copper to Gold." Journal of Bahá’í Studies 3, no. 2 (June 1, 1990): 25–33. http://dx.doi.org/10.31581/jbs-3.2.428(1990).

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Four areas concerning the biography From Copper to Gold are discussed: the historical context of this biography, the approach and pace of the book, typical problems associated with the writing, and the groundwork of beliefs from which Dorothy Baker gained her strength. *This paper is adapted from the Hasan Balyuzi Memorial Lecture presented at the 10th Annual Conference of the Association for Bahá’í Studies, Vancouver, August 1985.

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3

Stepanov, V. A., V. Ye Kungurova, and I. A. Koidan. "Металлогения Камчатского срединного массива." Bulletin of the North-East Science Center, no. 4 (December 28, 2020): 39–54. http://dx.doi.org/10.34078/1814-0998-2020-4-39-54.

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The article describes the ore bearance of three stages of reflected activation of the Kamchatka middle massif: Late Cretaceous, Eocene, and Miocene. In the first stage, gold mineralization of the gold-quartz and gold-sulfide-quartz formations was formed; in the second - sulfide platinoid-copper-nickel; in the third - gold-copper-molybdenum-porphyry. The relationship of gold, sulfide platinoid-copper-nickel and gold-copper-molybdenum-porphyry mineralization with certain igneous rock complexes - (Kola, Dukuk and Lavkin) is shown. The mining of nickel, copper from the Shanuch deposit and gold from placers has been noted.

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4

Swinbourne, D. R., G. G. Barbante, and A. Strahan. "Influence of gold content on copper oxidation from silver-gold-copper alloys." Metallurgical and Materials Transactions A 27, no. 10 (October 1996): 3187–91. http://dx.doi.org/10.1007/bf02663869.

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5

Guan, Y., and K. N. Han. "The dissolution behavior of gold and copper from gold and copper alloys." Mining, Metallurgy & Exploration 10, no. 2 (May 1993): 66–74. http://dx.doi.org/10.1007/bf03403002.

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6

Erdenebold, U., C. M. Sung, and J. P. Wang. "Gold recovery from flotation concentrate from gold mine tailings using dissolve smelting." Journal of Mining and Metallurgy, Section B: Metallurgy 55, no. 3 (2019): 343–49. http://dx.doi.org/10.2298/jmmb181005038e.

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Gold flotation concentrate may contain relatively high concentrations of valuable metals such as iron, copper, and zinc, and occasionally, even precious metals such as gold. The major components of the concentrate are SiO2, Fe2O3, and Al2O3, but it also contains reactive sulphide minerals such as pyrite. The sulphides in the flotation concentrate are fully converted into an oxide form during oxidative roasting, therefore, the chemical composition of the roasted concentrate is considered to be a copper slag. High temperature smelting with additives to dissolve Au from the gold concentrate into a molten copper was used in the research. Gold greatly dissolved at 1600?? under a CaO/SiO2 ratio of 1.25, suggesting the increase in the dissolution of gold into molten copper with decreasing viscosity of the molten slag-like concentrate at high temperatures.

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7

Asonen, H., C. J. Barnes, M. Pessa, R. S. Rao, and A. Bansil. "Electronic structure of copper-rich copper-gold alloys." Physical Review B 31, no. 6 (March 15, 1985): 3245–50. http://dx.doi.org/10.1103/physrevb.31.3245.

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8

Ho, Hong Meng, Wai Lam, Serguei Stoukatch, Petar Ratchev, Charles J. Vath, and Eric Beyne. "Direct gold and copper wires bonding on copper." Microelectronics Reliability 43, no. 6 (June 2003): 913–23. http://dx.doi.org/10.1016/s0026-2714(03)00074-x.

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9

Zalesov, M. V., V. A. Grigoreva, V. S. Trubilov, and A. Ya Boduen. "Designing of engineering solutions to enhance efficiency of high-copper gold-bearing ore processing." Mining Industry Journal (Gornay Promishlennost), no. 5/2021 (November 12, 2021): 51–56. http://dx.doi.org/10.30686/1609-9192-2021-5-51-56.

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The modern metals industry is characterised by a downward trend in the quality of ores involved in processing, and conventional methods of extracting useful components are inefficient for raw materials with complex composition. To maintain the growing level of metal production it is required to introduce new efficient technologies for processing of low-grade and refractory ores as well as man-made deposits. The article describes processing methods of refractory raw materials with high cyanide content using copper-gold ores as an example, where gold is the primary commodity, and copper is the accompanying useful component. The most common method of processing copper-gold ores is preconcentration followed by selective leaching of copper and gold. In some cases, technologies involving copper by-products and cyanide recovery from the cyanide leaching solutions offer equally effective options for processing of the copper-gold ores and concentrates. Copper-gold ores are processed at gold mines using the cyanide procedures, supplemented if required by gravity and flotation concentration. In all variations of the cyanide treatment, most of copper minerals actively react with cyanides of alkali metals, binding the CN– ions into the copper complex of [Cu(CN3)]2–. This reaction results in an increased solvent consumption, as well as in number of challenges related to cleaning tailings and slurries from highly toxic cyanide compounds and dissolved copper. In addition to technological complications associated with the need to meet strict requirements for the maximum permissible concentrations, copper accumulated in the cycling solutions also causes a decrease in gold extraction from the processed ores.

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10

Yin, Na, Wen Qing Qu, Shu Juan Yang, Rui Li, and Ying Ding. "Welding Technology of Gold Alloy." Advanced Materials Research 629 (December 2012): 214–19. http://dx.doi.org/10.4028/www.scientific.net/amr.629.214.

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Conducting ring is an electric transmission device to achieve current, video, data signal and power transmission between two relatively slewing mechanism, so it has been widely used in all kinds of precision turntable and inertial navigation equipment. The slip ring and brush wire of conducting ring are connected to other equipment by copper wire or copper transfer metal plates. Currently, Eutectic 63Sn-37Pb solder and electric iron manual welding are often used. But for gold alloy, when SnPb solder is used, gold element will dissolve in solder because Au dissolves in Sn easily, and brittleness intermetallic was produced at the interface during cooling, which embrittled the joint. This paper analyzed the solderability of gold alloy and copper, summed up the research status of soldering technology of gold alloy and copper in China and abroad. It pointed out that it is necessary and urgent to develop soldering technology of gold alloy with copper.

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11

Verbetsky, V. N., and S. V. Mitrokhin. "Copper- Silver- and Gold-Hydrogen." Solid State Phenomena 73-75 (August 2000): 503–0. http://dx.doi.org/10.4028/www.scientific.net/ssp.73-75.503.

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12

Lyabin, Nikolai A., and M. A. Kazaryan. "Copper and gold vapour lasers." Quantum Electronics 31, no. 6 (June 30, 2001): 564. http://dx.doi.org/10.1070/qe2001v031n06abeh013096.

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13

Carlson, Leif. "The Pahtohavare copper-gold prospect." Geologiska Föreningen i Stockholm Förhandlingar 113, no. 1 (March 15, 1991): 45–46. http://dx.doi.org/10.1080/11035899109453807.

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14

Tran, D. T., I. P. Jones, R. L. Johnston, J. A. Preece, and C. R. van den Brom. "Truncated-octahedral copper-gold nanoparticles." Journal of Physics: Conference Series 241 (July 1, 2010): 012086. http://dx.doi.org/10.1088/1742-6596/241/1/012086.

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15

Guan, Yichang, and Kenneth N. Han. "An electrochemical study on the dissolution of gold and copper from gold/copper alloys." Metallurgical and Materials Transactions B 25, no. 6 (December 1994): 817–27. http://dx.doi.org/10.1007/bf02662764.

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16

Musayev, Vladimir V., Anton M. Klyushnikov, and Ramil R. Galimov. "Study on the extraction of metals from tails of flotation enrichment of copper sulfide ores." Butlerov Communications 57, no. 2 (February 28, 2019): 50–59. http://dx.doi.org/10.37952/roi-jbc-01/19-57-2-50.

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Flotation processing of copper-pyrite ores is accompanied by the formation of flotation tailings containing 0.2-0.7 % wt Cu and 0.6-1.4 g/t Au. Deeper extraction of these components into commercial products is of practical interest. The possibility of additional recovery of copper and gold using the example of tailings from the current processing of PJSC “Gaysky GOK” was studied. It was shown that thin emulsion impregnation of chalcopyrite (less than 10 μ) in pyrite prevented the copper and gold from being extracted from the tailings by ore dressing methods. A scheme for the deep extraction of valuable components, based on the preliminary concentration of gold and copper by pyrite flotation, was proposed. About 84.5% of gold and 60.9% of copper were extracted into pyrite concentrate, while the gold content in the chamber product was 0.25 g/t. The increase in the extraction of copper was impossible due to nature of copper phase in chamber product that consisted mainly of copper oxides. Further processing of the pyrite concentrate can be accomplished by the way based on oxidative roasting (550-600 °C), with subsequent sulfuric acid leaching of copper from the calcine, washing and cyanidation of washed cake. Acid leaching is recommended to be done without external heating with solutions of 10-20 g/l of sulfuric acid. Copper was precipitated from leachates by cementation with iron powder in the form of copper concentrate (22-32 % wt Cu), then the gold-containing solution is processed to produce ligature gold. The optimal conditions for the cyanidation of the calcine were determined as follows, L:S = 2, the initial concentration of NaCN was 2 g/l, the duration of cyanidation was 2 hours The possibility of achieving end-to-end extraction of 66% of gold, and 45% of copper in commercial products is shown. The proposed scheme makes it possible to reduce the specific consumption of NaCN during cyanidation from 2.5-2.8 to 0.8 kg/t of tailings. It is assumed to gain sulfuric acid from the burning gases.

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17

Volskyi, R., T. Bulavinets, and I. Yaremchuk. "SIZE EFFECT IN PLASMON RESONANCE OF GOLD-COPPER SULFIDE CORE-SHELL NANOPARTICLES." Information and communication technologies, electronic engineering 2, no. 2 (December 2022): 133–40. http://dx.doi.org/10.23939/ictee2022.02.133.

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This paper studies the nature of changes in extinction spectra when changing the core/shell size ratio in spherical and ellipsoidal (prolate and oblate) gold-copper sulfide (Au-CuS) core-shell nanoparticles. The obtained results are analyzed to establish the regularity of changes in the nanoshells extinction spectra, which can be used to develop devices based on them for different applications. The plasmon properties of spherical and ellipsoidal Au -CuS nanoparticles with different sizes were determined. It is established that the intensity of the extinction cross-section of spherical nanoshells strongly depends on the ratio between the thickness of the core and the shell. It is possible to configure the plasmon properties of oblate and prolate ellipsoidal core-shell nanoparticles by changing the core and shell thickness in both directions. Thus, the results of the study suggest that Au-CuS nanoparticles can be used as potential elements of various sensitive sensors.

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18

Kalidass, Bhagyalakshmi, Muhammad Farhan Ul-Haque, Bipin S. Baral, Alan A. DiSpirito, and Jeremy D. Semrau. "Competition between Metals for Binding to Methanobactin Enables Expression of Soluble Methane Monooxygenase in the Presence of Copper." Applied and Environmental Microbiology 81, no. 3 (November 21, 2014): 1024–31. http://dx.doi.org/10.1128/aem.03151-14.

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ABSTRACTIt is well known that copper is a key factor regulating expression of the two forms of methane monooxygenase found in proteobacterial methanotrophs. Of these forms, the cytoplasmic, or soluble, methane monooxygenase (sMMO) is expressed only at low copper concentrations. The membrane-bound, or particulate, methane monooxygenase (pMMO) is constitutively expressed with respect to copper, and such expression increases with increasing copper. Recent findings have shown that copper uptake is mediated by a modified polypeptide, or chalkophore, termed methanobactin. Although methanobactin has high specificity for copper, it can bind other metals, e.g., gold. Here we show that inMethylosinus trichosporiumOB3b, sMMO is expressed and active in the presence of copper if gold is also simultaneously present. Such expression appears to be due to gold binding to methanobactin produced byM. trichosporiumOB3b, thereby limiting copper uptake. Such expression and activity, however, was significantly reduced if methanobactin preloaded with copper was also added. Further, quantitative reverse transcriptase PCR (RT-qPCR) of transcripts of genes encoding polypeptides of both forms of MMO and SDS-PAGE results indicate that both sMMO and pMMO can be expressed when copper and gold are present, as gold effectively competes with copper for binding to methanobactin. Such findings suggest that under certain geochemical conditions, both forms of MMO may be expressed and activein situ. Finally, these findings also suggest strategies whereby field sites can be manipulated to enhance sMMO expression, i.e., through the addition of a metal that can compete with copper for binding to methanobactin.

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19

Yanbo, Chen, Qin Guanglin, Li Guangsheng, Zhu Xingfu, Yu Congquan, Lu Zhongbo, Ji Qiang, et al. "Experimental study on thiosulfate leaching of gold from a high copper gold concentrate." E3S Web of Conferences 271 (2021): 04001. http://dx.doi.org/10.1051/e3sconf/202127104001.

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The conventional cyanide leaching process is used to extract gold from a high copper gold concentrate. Because the copper associated minerals consume sodium cyanide in large quantities, the cost of the reagents is high and the economic benefit is not ideal. At the same time, a large number of cyanide tail slag are produced, which brings a series of environmental problems. In order to solve the environmental problems caused by excessive sodium cyanide consumption and cyanogen slag, the feasibility of leaching gold by thiosulfate in copper ammonia system was studied. The gold leaching rate of thiosulfate was increased to more than 90% by using the direct thiosulfate leaching process and pretreatment thiosulfate leaching process, which was close to the gold leaching index of sodium cyanide at the production site.

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20

Yakubovsky, Dmitry I., Yury V. Stebunov, Roman V. Kirtaev, Kirill V. Voronin, Artem A. Voronov, Aleksey V. Arsenin, and Valentyn S. Volkov. "Graphene-Supported Thin Metal Films for Nanophotonics and Optoelectronics." Nanomaterials 8, no. 12 (December 15, 2018): 1058. http://dx.doi.org/10.3390/nano8121058.

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Graphene-metal hybrid nanostructures have attracted considerable attention due to their potential applications in nanophotonics and optoelectronics. The output characteristics of devices based on such nanostructures largely depend on the properties of the metals. Here, we study the optical, electrical and structural properties of continuous thin gold and copper films grown by electron beam evaporation on monolayer graphene transferred onto silicon dioxide substrates. We find that the presence of graphene has a significant effect on optical losses and electrical resistance, both for thin gold and copper films. Furthermore, the growth kinetics of gold and copper films vary greatly; in particular, we found here a significant dependence of the properties of thin copper films on the deposition rate, unlike gold films. Our work provides new data on the optical properties of gold and copper, which should be considered in modeling and designing devices with graphene-metal nanolayers.

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21

McInnes, Brent I. A., Jannene S. McBride, Noreen J. Evans, David D. Lambert, and Anita S. Andrew. "Osmium Isotope Constraints on Ore Metal Recycling in Subduction Zones." Science 286, no. 5439 (October 15, 1999): 512–16. http://dx.doi.org/10.1126/science.286.5439.512.

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Veined peridotite xenoliths from the mantle beneath the giant Ladolam gold deposit on Lihir Island, Papua New Guinea, are 2 to 800 times more enriched in copper, gold, platinum, and palladium than surrounding depleted arc mantle. Gold ores have osmium isotope compositions similar to those of the underlying subduction-modified mantle peridotite source region, indicating that the primary origin of the metals was the mantle. Because the mantle is relatively depleted in gold, copper, and palladium, tectonic processes that enhance the advective transport and concentration of these fluid soluble metals may be a prerequisite for generating porphyry-epithermal copper-gold deposits.

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22

Pham, V. A., and Yen Peng Ting. "Gold Bioleaching of Electronic Waste by Cyanogenic Bacteria and its Enhancement with Bio-Oxidation." Advanced Materials Research 71-73 (May 2009): 661–64. http://dx.doi.org/10.4028/www.scientific.net/amr.71-73.661.

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This work compares gold bioleaching from e-waste containing gold and copper by Chromobacterium violaceum and Pseudomonas fluorescens. The effect of pulp density (ranging from 0.5 to 8%w/v) was examined. Although C. violaceum produced more cyanide than P. fluorescens in the absence of e-waste, P. fluorescens showed higher growth rate, cyanide production and gold leaching efficiency at all pulp densities. Pretreatment with biooxidation of the e-waste using Acidithiobacillus ferrooxidans resulted in the removal in excess of 80% of the copper present in the waste, and increased the gold/copper ratio in the residual solid. Bioleaching the biooxidised e-waste significantly improved gold recovery, especially by C. violaceum, particularly at high pulp density. For example, at pulp densities of 2 and 4% w/v, gold recovery from non-biooxidzed e-waste was 0.22 and 0.14% respectively. Higher gold recovery, at 8%, was obtained for bioleaching of the biooxidised e-waste at both these pulp densities. The ratio of gold/copper in leachates after bioleaching of the biooxidized e-waste was also found to be increased.

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23

Ayata, S., and H. Yildiran. "Copper extraction from gold bearing copper(II) sulphide without thermal process to obtain gold concentrate." Minerals Engineering 18, no. 8 (July 2005): 901–4. http://dx.doi.org/10.1016/j.mineng.2005.01.019.

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24

Yin, Jian Feng, Si Hui Zhan, and He Xu. "Comparison of Leaching Processes of Gold and Copper from Printed Circuit Boards of Waste Mobile Phone." Advanced Materials Research 955-959 (June 2014): 2743–46. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.2743.

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Waste mobile phone has become the largest number of electronic waste, and recycling of metals from mobile phone would ensure resource recycling and reduce environmental degradation. Based on the contents of metals analyzed by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), containing copper and precious metals such as gold, the paper compared the extraction processes of gold, copper from waste mobile phone printed circuit board (PCB). In this study, two processes, nitric acid and thiourea (NT), sulfuric acid-hydrogen peroxide and iodine (SAHPI) were used to leach copper and gold, respectively. The recovery rate of copper was found to be 96.42%, and 94.3% of the gold was leached in the former process. Similar trends were obtained for the leaching of copper and gold in the latter process, but it was lower that about 95.27% of copper was recycled, while 93.4% of gold were leached. Both the two processes were nontoxic and non-cyanide system. However, thiourea is not stable and easy to decompose in alkaline solution, and the technology has disadvantage of instability. Iodine leaching on the other hand is comparatively a environmental process. Therefore, the optimal choice is the combined process of SAHPI method, while further research is required to develop cost effective and environmentally friendly processes.

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25

Faiberg, Anna A., Aleksandra N. Mikhailova, Vladimir E. Dementiev, and Sergey S. Gudkov. "Biogenic Hydrogen Sulfide for Cyanide Regeneration in Solutions during Cupriferous Gold Ores Processing." Solid State Phenomena 262 (August 2017): 131–34. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.131.

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An optimal approach to the problem of cupriferous gold ores hydrometallurgical processing is the recycling of process solutions after copper recovery and regeneration of cyanide bound in complexes. The study focuses on the copper-cyanide solutions processing technology using biogenic hydrogen sulfide for copper recovery in the form of сhalcocite, and cyanide regeneration. The strains of anaerobic sulfidogenic thermophilic microorganisms Desulfurella acetivorans and Desulfurella Kamchatkensis were used for producing hydrogen sulfide. The studies on copper precipitation and cyanide regeneration were conducted on copper-cyanide process solutions which were obtained during cyanidation of refractory cupriferous gold-bearing flotation concentrates from one of the deposits in the South Ural (Russia). Ten cycles of "Cyanidation-Regeneration" were carried out in total. The copper recovery was 86–96 %; the cyanide regeneration obtained 96 %. On an average 8.9 kg of sodium cyanide and 4.6 kg of copper sulfide were recovered from 1 m3 of solution. The sodium cyanide consumption decreased from 25.0 kg/t to 6.0 kg/t without reducing gold recovery during the CIL (carbon-in-leach) recycling process. The gold recovery was the same 63–68 %.

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26

Utama, Anak Agung Gde Satia, and Ika Putri Elviana. "NARCISSISM NARRATIVE TEXT ANALYSIS OF SEMIOTIC DISCLOSURE ANNUAL REPORT PT MERDEKA COPPER GOLD TBK." JOURNAL OF ACCOUNTING, ENTREPRENEURSHIP AND FINANCIAL TECHNOLOGY (JAEF) 3, no. 2 (April 28, 2022): 115–32. http://dx.doi.org/10.37715/jaef.v3i2.2652.

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The purpose of this study is to analyze the phenomenon of narcissism on the case study in a business operation project of PT Merdeka Copper Gold Tbk. in Tumpang Pitu Banyuwangi. In addition, as a company that uses narcissism narrative text for PT Merdeka Copper Gold Tbk. The primary data is from the annual report of PT Merdeka Copper Gold Tbk. in 2015 - 2016 analyzed using semiotic analysis. The results of this study indicate that PT Merdeka Copper Gold Tbk. used narcissism of narrative text that is persuasive to stakeholders with positive performance, especially in the delivery of CSR with exaggeration in the annual report. It is a communicative management action to gain legitimacy, and to create a positive image to stakeholders.

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Forrest, K., D. Yan, and R. Dunne. "Optimisation of gold recovery by selective gold flotation for copper-gold-pyrite ores." Minerals Engineering 14, no. 2 (February 2001): 227–41. http://dx.doi.org/10.1016/s0892-6875(00)00178-3.

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Sugino, Shigeaki, Takashi Hori, and Hisato Hagiwara. "Activity of Zinc in Molten Gold and Gold-Copper Alloy." Journal of the Japan Institute of Metals 56, no. 7 (1992): 779–84. http://dx.doi.org/10.2320/jinstmet1952.56.7_779.

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Mulyasuryani, Ani, Bambang Ismuyanto, and Danar Purwonugroho. "Pemurnian Emas dari Bijih Emas Berkadar Rendah Menggunakan Karbon Aktif dari Arang Tempurung Kelapa." Jurnal Natur Indonesia 14, no. 1 (November 21, 2012): 1. http://dx.doi.org/10.31258/jnat.14.1.1-6.

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The activated carbon from the coconut shell can be used as an adsorbent for the recovery of gold. The optimum condition for gold recoverywas obtained at pH 3 (for adsorption) and pH 5 (for desorption) with 1 M thyocyanate solution and a 5 cm length of column (the mass ofactivated carbon is 20 grams). In this condition, the average gold recovery is 90.00%, silver 7.28% and copper 4.93%, that were used severalgold ore samples. The average purity degree of gold is 49.67%, depend on the concentration of gold, silver and copper in the gold oresample.

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30

Ippolito, Nicolò Maria, Franco Medici, Loris Pietrelli, and Luigi Piga. "Effect of Acid Leaching Pre-Treatment on Gold Extraction from Printed Circuit Boards of Spent Mobile Phones." Materials 14, no. 2 (January 13, 2021): 362. http://dx.doi.org/10.3390/ma14020362.

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The effect of a preliminary acid leaching for the recovery of gold by thiourea from printed circuit boards (PCBs) of spent mobile phones, was investigated. Preliminary leaching is aimed to recover copper in the leachate that would compete with gold in the successive leaching of the residue with thiourea, thus preventing the formation of the gold-thiourea complex. Two hydrometallurgical routes were tested for the recovery of copper first, and gold after. The first one was based on a two-step leaching that utilizes sulfuric acid and hydrogen peroxide in the preliminary leaching and then thiourea for the recovery of gold in the successive leaching: A copper and gold recovery of 81% and 79% were obtained, respectively. In the second route, nitric acid was used: 100% of copper was recovered in the leachate and 85% of gold in the thiourea successive leaching. The main operative parameters, namely thiourea and ferric sulphate concentrations, leach time, liquid-solid ratio, and temperature were studied according to a factorial plan strategy. A flowsheet of the processes was proposed, and a mass balance of both routes was obtained. Finally, qualitative considerations on the technical and economic feasibility of the different routes were made.

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31

Tan, Li-Ping. "The Chinkuashih Gold-Copper Deposits, Taiwan." SEG Discovery, no. 7 (October 1, 1991): 1–24. http://dx.doi.org/10.5382/segnews.1991-07.fea.

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32

Deschênes, G., and P. J. H. Prud'homme. "Cyanidation of a copper-gold ore." International Journal of Mineral Processing 50, no. 3 (August 1997): 127–41. http://dx.doi.org/10.1016/s0301-7516(97)00008-2.

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33

Raghavan, V. "Al-Au-Cu (Aluminum-Gold-Copper)." Journal of Phase Equilibria and Diffusion 29, no. 3 (March 25, 2008): 260–61. http://dx.doi.org/10.1007/s11669-008-9286-z.

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Raghavan, V. "Al-Au-Cu (Aluminum-Gold-Copper)." Journal of Phase Equilibria and Diffusion 31, no. 6 (July 13, 2010): 544. http://dx.doi.org/10.1007/s11669-010-9765-x.

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35

Müller, Daniel. "Gold-copper mineralization in alkaline rocks." Mineralium Deposita 37, no. 1 (February 2002): 1–3. http://dx.doi.org/10.1007/s00126-001-0226-7.

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36

Radchenko, V. M., M. A. Ryabinin, T. A. Chernakova, and S. V. Tomilin. "Americium alloys with gold and copper." IOP Conference Series: Materials Science and Engineering 9 (March 1, 2010): 012093. http://dx.doi.org/10.1088/1757-899x/9/1/012093.

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37

Strohmeier, Brian R. "Copper/Silver/Gold Alloy by XPS." Surface Science Spectra 3, no. 3 (July 1994): 175–81. http://dx.doi.org/10.1116/1.1247744.

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38

Knowles, M. R. H., R. Foster-Turner, and A. J. Kearsley. "Copper lasers go for industrial gold." IEEE Circuits and Devices Magazine 10, no. 5 (September 1994): 39–42. http://dx.doi.org/10.1109/101.313463.

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39

Straney, Patrick J., Christopher M. Andolina, and Jill E. Millstone. "Copper Deposition on Gold Nanoprism Substrates." Israel Journal of Chemistry 56, no. 4 (July 27, 2015): 257–61. http://dx.doi.org/10.1002/ijch.201500033.

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40

Li, Huan, Elsayed Oraby, Jacques Eksteen, and Tanmay Mali. "Extraction of Gold and Copper from Flotation Tailings Using Glycine–Ammonia Solutions in the Presence of Permanganate." Minerals 12, no. 5 (May 12, 2022): 612. http://dx.doi.org/10.3390/min12050612.

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This study presents the novel idea of a cyanide-free leaching method, i.e., glycine–ammonia leaching in the presence of permanganate, to treat a low-grade and copper-bearing gold tailing. Ammonia played a key role as a pH modifier, lixiviant and potential catalyst (as cupric ammine) in this study. Replacing ammonia with other pH modifiers (i.e., sodium hydroxide or lime) made the extractions infeasibly low (<30%). The increased additions of glycine (23–93 kg/t), ammonia (30–157 kg/t) and permanganate (5–20 kg/t) enhanced gold and copper extractions considerably. Increasing the solids content from 20 to 40% did not make any obvious changes to copper extraction. However, gold leaching kinetics was slightly better at lower solids content. It was indicated that the staged addition of permanganate was unnecessary under the leaching conditions. Recovery of gold by CIL was shown to be feasible, and it improved gold extraction by 15%, but no effect was observed for copper extraction. Percentages of 76.5% gold and 64.5% copper were extracted in 48 h at 20 g/L glycine, 10 kg/t permanganate, 20 g/L carbon, pH 10.5 and 30% solids. Higher extractions could be potentially achieved by further optimization, such as by increasing permanganate addition, extending leaching time and ultra-fine grinding.

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41

Das, A. K., H. P. Kilty, P. J. Marto, G. B. Andeen, and A. Kumar. "The Use of an Organic Self-Assembled Monolayer Coating to Promote Dropwise Condensation of Steam on Horizontal Tubes." Journal of Heat Transfer 122, no. 2 (December 23, 1999): 278–86. http://dx.doi.org/10.1115/1.521465.

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Hydrophobic coatings have been created through self-assembled monolayers (SAMs) on gold, copper, and copper-nickel alloy surfaces that enhance steam condensation through dropwise condensation. The monolayer is formed by chemisorption of alkylthiols on these metal surfaces. Due to their negligible thickness (10–15 Å), SAMs have negligible heat transfer resistance, and involve a minuscule amount of the organic material to pose any contamination problem to the system from erosion of the coating. The coating was applied directly to copper and 90/10 copper-nickel tubes, and to previously gold-sputtered aluminum tubes. The quality of the drops on SAMs, based on visual observation, was found to be similar for the three surfaces, with the gold surface showing a slight superiority. When compared to complete filmwise condensation, the SAM coating increased the condensation heat transfer coefficient by factors of 4 for gold-coated aluminum, and by about 5 for copper and copper-nickel tubes, under vacuum operation (10 kPa). The respective enhancements under atmospheric conditions were about 9 and 14. Comparatively, the heat transfer coefficient obtained with a bare gold surface (with no organic coating) was 2.5 times that of the filmwise condensation heat transfer coefficient under vacuum, and 3.4 at atmospheric conditions. [S0022-1481(00)02502-0]

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42

Delannoy, Laurent, Gode Thrimurthulu, Padigapati S. Reddy, Christophe Méthivier, Jaysen Nelayah, Benjaram M. Reddy, Christian Ricolleau, and Catherine Louis. "Selective hydrogenation of butadiene over TiO2supported copper, gold and gold–copper catalysts prepared by deposition–precipitation." Phys. Chem. Chem. Phys. 16, no. 48 (July 22, 2014): 26514–27. http://dx.doi.org/10.1039/c4cp02141j.

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43

Sugino, Shigeaki, and Hisato Hagiwara. "Activity of Zinc in Molten Copper and Copper-Gold Alloys." Journal of the Japan Institute of Metals 50, no. 2 (1986): 186–92. http://dx.doi.org/10.2320/jinstmet1952.50.2_186.

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44

Reznickova, Alena, Petr Slepicka, Hoang Yen Nguyenova, Zdenka Kolska, Marcela Dendisova, and Vaclav Svorcik. "Copper–gold sandwich structures on PE and PET and their SERS enhancement effect." RSC Advances 7, no. 37 (2017): 23055–64. http://dx.doi.org/10.1039/c7ra01010a.

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In this paper we have investigated the SERS effect of gold–copper sandwich structures i.e. the coupling between surface plasmon polaritons supported by the gold grating and localized surface plasmons excited on the grafted copper nanoparticles.

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45

Chernykh, Aleksander, Alexey Shirobokov, and Irina Arsentieva. "Gold metallogeny of the East Tannu-Ola ore region, Tyva Republic." Ores and metals, no. 2 (August 16, 2021): 40–67. http://dx.doi.org/10.47765/0869-5997-2021-10010.

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The Elegest-Mezhegei, Aptara, and Shivilig forecasted gold ore clusters and the Kharalyg and Irbitei forecasted gold-silver-polymetallic ore clusters were distinguished within the East Tannu-Ola iron-copper-polymetallic-gold ore region, based on examination of historical and new geological, geochemical, and metallogenical data. Subsequently, the Urgailyg, Proezdnoe, and Chumurtuk forecasted gold ore fields were delineated within the Elegest-Mezhegei cluster; the Despen ore field was delineated within the Aptara ore cluster; and the Ovur-Ongesh ore field was outlined within the Shivilig cluster. In addition, the Ulug-Sailyg and Ak-Charinsk gold-molybdenum-copper ore fields were distinguished outside the ore clusters. The article summarizes the investigation history, geological-structural position, geological features, and geochemical specialization of the rocks of the East Tannu-Ola region. Descriptions of the ore clusters embrace peculiarities of their geological structure, ore mineralogy, and native gold, as well as parameters of the gold-sulfide-quartz, goldskarn, gold-containing polymetallic VMS, and porphyry molybdenum-copper mineralized zones. The conclusions highlight the metallogenic epochs and distribution regularities of the gold and gold-containing mineralization within the region studied.

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46

Cabello, José. "Gold Deposits in Chile." Andean Geology 48, no. 1 (January 29, 2021): 1. http://dx.doi.org/10.5027/andgeov48n1-3294.

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A review of gold and gold bearing base metals deposits in Chile, indicate the existence of at least six different type of ore deposits, most largely formed during the Cenozoic with predominance in the Miocene. Mesozoic deposits are common but less relevant regarding their size and gold content. These hydrothermal ore deposits are genetically associated with subduction related Andean arc magmatism. Due to its relationship with episodic magmatism migrating eastward, there is a tendency for the deposits to be in distinct, north-south trending, belts with a progressive west to east decrease in mineralization age. After analysing 82 cases in total, main gold concentration can be assigned to high-sulfidation epithermal and porphyry type deposits. Low-sulfidation epithermal, IOCG and mesothermal type appears as less relevant. Gold bearing copper deposits constitute an important part of Chile’s total gold production. Both IOCG type but especially porphyry copper deposits are and will remain as a substantial source to supplement the future output of the gold in the country. The 82 deposits with their tonnage and grade studied, represent a total gold content of 11,662 t equivalent to 375 Moz, excluding past production for those exploited. A number of probable gold bearing base metals high tonnage deposits (IOCG and porphyry copper) do not include their gold content in public format, hence the number delivered could be estimated conservative. Methodical geochronological, ore types and zonation studies are required to better appreciate this metallogenic setting widening current understanding and future exploration results.

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Chauvin, Adrien, Cyril Delacôte, Mohammed Boujtita, Benoit Angleraud, Junjun Ding, Chang-Hwan Choi, Pierre-Yves Tessier, and Abdel-Aziz El Mel. "Dealloying of gold–copper alloy nanowires: From hillocks to ring-shaped nanopores." Beilstein Journal of Nanotechnology 7 (September 29, 2016): 1361–67. http://dx.doi.org/10.3762/bjnano.7.127.

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We report on a novel fabrication approach of metal nanowires with complex surface. Taking advantage of nodular growth triggered by the presence of surface defects created intentionally on the substrate as well as the high tilt angle between the magnetron source axis and the normal to the substrate, metal nanowires containing hillocks emerging out of the surface can be created. The approach is demonstrated for several metals and alloys including gold, copper, silver, gold–copper and gold–silver. We demonstrate that applying an electrochemical dealloying process to the gold–copper alloy nanowire arrays allows for transforming the hillocks into ring-like shaped nanopores. The resulting porous gold nanowires exhibit a very high roughness and high specific surface making of them a promising candidate for the development of SERS-based sensors.

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48

Chauvin, Adrien, Marta Lafuente, Jean Yves Mevellec, Reyes Mallada, Bernard Humbert, Maria Pilar Pina, Pierre-Yves Tessier, and Abdelaziz El Mel. "Lamellar nanoporous gold thin films with tunable porosity for ultrasensitive SERS detection in liquid and gas phase." Nanoscale 12, no. 23 (2020): 12602–12. http://dx.doi.org/10.1039/d0nr01721c.

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Porous gold lamellar structure with high SERS performance is created by copper chemical etching of a pure gold and pure copper stacked layers. SERS response is recorded for trace level detection of probe molecule in liquid and gas phase.

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49

Avdalovic, Jelena, Tatjana Solevic-Knudsen, Biljana Dojcinovic, Vesna Conic, Jun Yao, Chao Lu, and Miroslav Vrvic. "Bioleaching of copper, zinc and gold from a polymetallic ore flotation concentrate from the Coka Marin deposit (Serbia)." Journal of the Serbian Chemical Society, no. 00 (2021): 16. http://dx.doi.org/10.2298/jsc210127016a.

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The aim of this study was to investigate the possibility of applying Acidithiobacillus sp. B2 to copper, zinc and gold recovery from a polymetallic ore flotation concentrate. The study was designed in two phases. The first phase was a classic biooxidation process in which the microorganisms oxidize sulfides, leaching copper and zinc while simultaneously concentrating gold in the ore. In the second phase, after elimination of the sulfide substrate, the rate of gold leaching by potassium cyanide was analyzed. The leaching was conducted using the shake flask testing technique during a period of 28 days at a temperature of 28 ?C. The percentage of copper and zinc leached at the end of this study was 37.63 % and 47.95 % respectively. The results obtained indicated 6- and 13-fold (for copper and zinc, respectively) higher metal leaching efficiency in the suspension with iron-oxidizing Acidithiobacillussp. B2 than in the control suspension. In the next phase of the study, after elimination of the sulfide substrate, gold was extracted with potassium cyanide from the remaining polymetallic ore concentrate. The results obtained showed that the efficiency of the gold extraction process was 80 %. According to the available data, this is the first study of the microbiological leaching of copper, zinc and gold from a polymetallic ore flotation concentrate from the Coka Marin deposit (Serbia).

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Chen, Junnan, Feng Xie, Wei Wang, Yan Fu, and Jian Wang. "Leaching of Gold and Silver from a Complex Sulfide Concentrate in Copper-Tartrate-Thiosulfate Solutions." Metals 12, no. 7 (July 6, 2022): 1152. http://dx.doi.org/10.3390/met12071152.

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The leaching behaviors of gold and silver from a complex sulfide concentrate in copper-tartrate-thiosulfate solutions were investigated in this paper. Experimental parameters, including temperature, initial pulp pH, and concentration of copper, tartrate, and thiosulfate, were systematically studied. The copper-tartrate-thiosulfate leaching system exhibits promising performance in dealing with the complex sulfide concentrate. Thiosulfate consumption could be greatly reduced due to the in-situ generation of thiosulfate derived from sulfur or disulfide ions. Increasing the temperature and concentrations of copper, tartrate, and thiosulfate can promote gold leaching. A low tartrate content and a moderate increase in temperature and copper and thiosulfate concentrations can accelerate silver leaching, but a higher temperature or copper content may depress silver extraction. A suitable pulp pH is critical for gold and silver leaching in copper-tartrate-thiosulfate solutions. An extraction of 74.50% Au and 36.33% Ag was obtained with the direct leaching of the concentrate, while the percentages can be significantly increased up to 82.60% and 70.38%, respectively, when leaching the calcine following the oxidative roasting pretreatment. The recycling of leaching solutions demonstrates that a suitable free tartrate content is of great significance in maintaining the stability of the novel system. As an alternative to the traditional cyanide or copper-ammonia-thiosulfate leaching processes, the copper-tartrate-thiosulfate leaching system provides an environmentally friendly, nontoxic, and relatively low-cost method for gold and silver leaching from ores or concentrates.

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Journal articles on the topic 'Copper-gold'

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