• Title, Summary, Keyword: Copper

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A Study on Bacterial Leaching of Low-Grade Copper Mineral(IV) (저품위 동광석의 세균침출에 관한 연구 4)

  • 박원구;이강순
    • Korean Journal of Microbiology
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    • v.11 no.4
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    • pp.189-195
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    • 1973
  • With the gradual expansion of copper demands, the utilization of enormous tonnages of waste copper mineral containig up to 0.5% copper becomes available. In order to investigate the possibilities on the application of bacterial leaching method to waste dumps or abandoned mines, the authors had carried out microbial leaching of copper minerals by F.ferrooxidans isolated from the Dalsung copper mine water. The results obtained were as follows : 1. The copper extraction rate from the Dalsung chalcopyrite has been a little accerelated by using flasks in place of percolators. 2. The percentage of copper extracted from the Dalsung chalcopyrite sample was 100% in 30 days in the presence of iron-oxidizing bacteria F.ferrooxidans while 9.27% in the absence of bacteria. 3. F.ferroxidans was capable of producing sufficient quantities of ferric sulfate and sulfuric acid from ferrous iron to bring about the dissolution of 100% of copper from the Dalsung chalcopyrite.

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A Study on Improvement of Light Fastness on Silk-Dyed Fabric by Aftertreatment with Copper Sulfate/Thiourea (황산구리/치오요소 후처리에 의한 견직물의 일광 견뢰도 증진에 관한 연구)

  • 윤정임;김경환
    • Textile Coloration and Finishing
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    • v.5 no.2
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    • pp.117-124
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    • 1993
  • The Silk fabric was dyed with various acid dyes, and than treated with copper sulfate or copper sulfate/thiourea. Munsell color system, dye exhaustion and light fastness were investigated for the treated fabrics. The results obtaind are as follows: 1) The color variation of the silk-dyed fabric by aftertreatment with copper sulfate was shown redish, but original color with copper sulfate/thiourea. 2) Copper sulfate/thiourea was much more effective than copper sulfate only to increase the light fastness. 3) The crease recovery was increased by aftertreatment with copper sulfate/thiourea. 4) Dye exhaustion and tensile strength of the silk-dyed fabric by aftertreatment with copper sulfate was decreased about 8-15% more than those of untreated.

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A Study on Improvement of Fastness on Cotton-dyed Fabric by Aftertreatment with Copper Sulfate/Thiourea (황산구리/치오요소 후처리에 희한 직접염료의 견뢰도 증진에 관한 연구(II))

  • Yoon, Jung Im;Kim, Kyung Hwan
    • Textile Coloration and Finishing
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    • v.5 no.4
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    • pp.1-9
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    • 1993
  • The Cotton fabric was dyed with various directd dyes, and then treated with copper sulfate or copper sulfate/thiourea. Munsell color system, dye exhaustion, tensile strength, light fastness, washing fastness and rubbing fastness were investigated for the treated fabrics. The results obtaind are as follows: 1. The color variation of the cotton-dyed fabric by aftertreatment with copper sulfate was shown redish, but original color with copper sulfate/thiourea. 2. Copper sulfate/thiourea was much more effective than copper sulfate only to increase the light fastness, washing fastness and rubbing fastness. 3. Dye exhaustion of the cotton-dyed fabric by aftertreatment with copper sulfate was decreased about 20% more than those of untreated. 4. Tensile stregth of cotton-dyed fabric by aftertreatment with copper sulfate/thiourea was decrease about 10% more than those of untreated.

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Evolutional Transformations of Copper Nanoparticles to Copper Oxide Nanowires

  • Gang, Min-Gyu;Yun, Ho-Gyu;Kim, Yeong-Seok
    • Proceedings of the Materials Research Society of Korea Conference
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    • pp.18.2-18.2
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    • 2011
  • We study and analyze here a novel and simple approach to produce copper oxide nanowires in a methanol as an alternative to chemical synthesis routs and VLS-growth method. First, copper oxide nanowires are grown from copper nanoparticles in methanol at $60^{\circ}C$. Nanoparticles are synthesized via inert gas condensation, one of the dry processes. Synthesized nanowires were confirmed via XRD, FESEM and TEM. As a result, all particles have grown to Cu2O nanowires (20~30 nm in diameter, 5~10 um in length; aspect ratio >160~500). Next, these synthesized oxide nanowires are reduced copper nanowires in the furnace under hydrogen flow at $200{\sim}450^{\circ}C$. The evolution of oxide nanowires and their transformation to copper nanowires is studied as a function of time.

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Study of defect characteristics by electrochemical plating thickness in copper CMP (Copper CMP에서 Electrochemical Plating 두께에 따른 Defect 특성 연구)

  • Kim, Tae-Gun;Kim, Nam-Hoon;Kim, Sang-Yong;Chang, Eui-Goo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.125-126
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    • 2005
  • Recently semiconductor devices are required more smaller scale and more powerful performance. For smaller scale of device, multilayer structure is proposed. And, for the higher performance, interconnection material is change to copper, because copper has high EM(Electro-migration)and low resistivity. Then copper CMP process is a great role in a multilayer formation of semiconductor. Copper process is different from aluminum process. ECP process is one of the copper processes. In this paper, we focused on the defects tendency by copper thickness which filled using ECP process. we observed hump high and dishing. Conclusively, hump hight reduced at copper thickness increased Also dishing reduced.

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Copper Electrode Material using Copper Formate-Bicarbonate Complex for Printed Electronics

  • Hwang, Jaeeun;Kim, Sinhee;Ayag, Kevin Ray;Kim, Hongdoo
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.147-150
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    • 2014
  • Copper ink has been prepared by mixing copper(II) formate and 2-ethyl-1-hexylammonium bicarbonate (EHABC) to overcome some weak points such as aggregation and degradation of copper nano-type ink. Ink was coated on glass substrate and calcined at $110^{\circ}C$ to $150^{\circ}C$ to generate electrically conductive copper film under two different atmospheres such as nitrogen gas and gaseous mixture of formic acid and methanol. The lowest resistivity of $1.88{\mu}{\Omega}{\cdot}cm$ of copper film was obtained at $150^{\circ}C$ in gaseous formic acid condition. The long-term resistivity shows to increase from $1.88{\mu}{\Omega}{\cdot}cm$ to $2.61{\mu}{\Omega}{\cdot}cm$ after one month.

Preparation and Characterization of Copper Oxychloride from Acidic Copper Chloride Etchant (PCB 산업에서 배출되는 산성 염화동 폐액으로부터 Copper Oxychloride의 제조 및 특성분석)

  • 김영희;김수룡;정상진;이윤주;어영선
    • Journal of the Korean Institute of Resources Recycling
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    • v.12 no.2
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    • pp.3-10
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    • 2003
  • Copper oxychloride used as an agricultural fungicide has been recovered from copper-containing waste etchant by the neutralization with alkali hydroxides. Large amount of copper-containing waste etchant is generated from Printed Circuit Board industry. In an environmental and economic point of view, retrieve of the valuable natural resource from the waste is important. Recycling process of copper oxychloride from the waste etchant is discovered through the our study. In the range of reaction temp. 2$0^{\circ}C$-4$0^{\circ}C$, pH 5-7, pure copper oxychloride was able to prepare and the yield of copper oxychloride was higher than 95%. Physical properties of the sample have been characterized using SEM, XRD, TGA, ICP and Atomic absorption spectroscopy.

Study on the Preparation of Copper Sulfate by Copper Powder using Cation Membrane Electrowinning Prepared from Waste Cupric Chloride Solution (염화동 폐액으로부터 양이온격막 전해 채취된 구리 분말을 이용한 황산동의 제조방법 연구)

  • Kang, Yong-Ho;Hyun, Soong-Keun
    • Journal of the Korean Institute of Resources Recycling
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    • v.28 no.1
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    • pp.62-72
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    • 2019
  • Generally, $H_2SO_4$ and Cu metal are used as raw materials for producing copper sulfate. The study relates to a method for producing copper sulfate using electrowinning from a waste solution of copper chloride. Uses are used for copper plating for industry, plating, feed, agriculture, electronic grade PCB. Conventional methods for producing copper sulfate have a problem of a large amount of waste water and a high energy cost. A study on the production method of copper sulfate ($CuSO_4$), which is the most used among copper (Cu) compounds, has a low process operation ratio, a small amount of waste water, and a simple manufacturing process. It is easy to remove Na, Ca, Mg, and Al as impurities by using a cationic membrane. At the same time, high purity copper powder could be recovered by an electrowinninng method. Using the recovered copper powder, high purity copper sulfate could be produced.

A Study on Abnormal Expansion of Fe-Cu Sintered Alloy (Fe-Cu계 소결합금의 이상팽창에 관한 연구 (I))

  • Song Young-Jun;Kim Youn-Che
    • Journal of Korean Powder Metallurgy Institute
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    • v.11 no.5
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    • pp.383-390
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    • 2004
  • In order to investigate behavior of abnormal expansion of the iron-copper compacts, we compared the dilatometric curves of the compacts which mixed the copper powder to the iron powder with those of compacts which mixed the copper powder to the iron-copper alloy powder. The dilatometric curves were obtained below the sintering conditions, which heated up to 115$0^{\circ}C$ by a heating rate of 1$0^{\circ}C$/min, held for 60min at 115$0^{\circ}C$ and cooled down at a rate of 2$0^{\circ}C$/min to room temperature. The dilatometric curves of the compacts showed the different expansion behavior at temperatures above the copper melting point in spite of same chemical composition. All of the compacts of former case showed large expansion, but all of the compacts in latter case showed large contraction. The microstructures of sintered compacts also showed the different progress in alloying of the copper into the iron powder. Namely we could observe the segregation at alloy part of copper into iron powder in case of the sintered compacts, which mixed the copper powder to the iron powder, but could not observe the segregation in compacts which mixed the copper powder to the iron-copper alloy powder. But the penetration of liquid copper into the interstices between solid particles was occurred at both cases. Therefore, the showing of the different dimensional changes in the compacts in spite of same chemical composition is due to more the alloying of copper into iron powder than the penetration of liquid copper into the interstices between solid particles.

Spatial Pattern of Copper Phosphate Precipitation Involves in Copper Accumulation and Resistance of Unsaturated Pseudomonas putida CZ1 Biofilm

  • Chen, Guangcun;Lin, Huirong;Chen, Xincai
    • Journal of Microbiology and Biotechnology
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    • v.26 no.12
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    • pp.2116-2126
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    • 2016
  • Bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. The spatial distribution and speciation of copper in unsaturated Pseudomonas putida CZ1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive X-ray analysis, and micro-X-ray fluorescence microscopy coupled with micro-X-ray absorption near edge structure (micro-XANES) analysis. It was found that copper was mainly precipitated in a $75{\mu}m$ thick layer as copper phosphate in the middle of the biofilm, while there were two living cell layers in the air-biofilm and biofilm-medium interfaces, respectively, distinguished from the copper precipitation layer by two interfaces. The X-ray absorption fine structure analysis of biofilm revealed that species resembling $Cu_3(PO_4)_2$ predominated in biofilm, followed by Cu-Citrate- and Cu-Glutathione-like species. Further analysis by micro-XANES revealed that 94.4% of copper were $Cu_3(PO_4)_2$-like species in the layer next to the air interface, whereas the copper species of the layer next to the medium interface were composed by 75.4% $Cu_3(PO_4)_2$, 10.9% Cu-Citrate-like species, and 11.2% Cu-Glutathione-like species. Thereby, it was suggested that copper was initially acquired by cells in the biofilm-air interface as a citrate complex, and then transported out and bound by out membranes of cells, released from the copper-bound membranes, and finally precipitated with phosphate in the extracellular matrix of the biofilm. These results revealed a clear spatial pattern of copper precipitation in unsaturated biofilm, which was responsible for the high copper tolerance and accumulation of the biofilm.