• 제목/요약/키워드: Cu diffusion

검색결과 443건 처리시간 0.026초

구리의 전압전류법적 파라미터에 미치는 압력의 영향 (Effect of High Pressure of Voltammetric Parameters of Copper)

  • 배준웅;이흥락;박홍순
    • 대한화학회지
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    • 제33권4호
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    • pp.399-405
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    • 1989
  • Cu(II)의 환원반응의 전압전류법적 파라미터에 미치는 압력의 영향을 0.5 M KCl 수용액 중에서 조사하였다. 미소백금전극, 표준칼로멜전극 및 나선형 백금선을 작업전극, 기준전극 및 보조전극으로 사용하였다. 압력을 1기압에서 1800기압까지 증가시킴에 따라 제 1환원파의 반파전위는 음전위쪽으로 많이 이동하였다. 그리고 제 1환원파와 제 2환원파의 확산전류는 1기압에서 약 1,000기압까지는 증가하였으나, 1,000기압 이상에서는 조금씩 감소하였다. 전 실험 압력범위($1{\sim}1800$기압)에서 제 1환원파의 확산 전류와 Cu(II)의 농도 사이에는 좋은 선형관계가 성립하였다. 각 환원반응의 가역성은 압력증가에 영향을 받지 않았다.

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Mineralogical studies and extraction of some valuable elements from sulfide deposits of Abu Gurdi area, South Eastern Desert, Egypt

  • Ibrahim A. Salem;Gaafar A. El Bahariya;Bothina T. El Dosuky;Eman F. Refaey;Ahmed H. Ibrahim;Amr B. ElDeeb
    • 분석과학
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    • 제37권1호
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    • pp.47-62
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    • 2024
  • Abu Gurdi area is located in the South-eastern Desert of Egypt which considered as volcanic massive sulfide deposits (VMS). The present work aims at investigating the ore mineralogy of Abu Gurdi region in addition to the effectiveness of the hydrometallurgical route for processing these ores using alkaline leaching for the extraction of Zn, Cu, and Pb in the presence of hydrogen peroxide, has been investigated. The factors affecting the efficiency of the alkaline leaching of the used ore including the reagent composition, reagent concentration, leaching temperature, leaching time, and Solid /Liquid ratio, have been investigated. It was noted that the sulfide mineralization consists mainly of chalcopyrite, sphalerite, pyrite, galena and bornite. Gold is detected as rare, disseminated crystals within the gangue minerals. Under supergene conditions, secondary copper minerals (covellite, malachite, chrysocolla and atacamite) were formed. The maximum dissolution efficiencies of Cu, Zn, and Pb at the optimum leaching conditions i.e., 250 g/L NaCO3 - NaHCO3 alkali concentration, for 3 hr., at 250 ℃, and 1/5 Solid/liquid (S/L) ratio, were 99.48 %, 96.70 % and 99.11 %, respectively. An apparent activation energy for Zn, Cu and Pb dissolution were 21.599, 21.779 and 23.761 kJ.mol-1, respectively, which were between those of a typical diffusion-controlled process and a chemical reaction-controlled process. Hence, the diffusion of the solid product layer contributed more than the chemical reaction to control the rate of the leaching process. High pure Cu(OH)2, Pb(OH)2, and ZnCl2 were obtained from the finally obtained leach liquor at the optimum leaching conditions by precipitation at different pH. Finally, highly pure Au metal was separated from the mineralized massive sulfide via using adsorption method.

Cu 담지 Ti-SBA-15 촉매의 선택적 CO 산화 반응 (Preferential Oxidation of CO over Cu/Ti-SBA-15 Catalysts)

  • 김준우;박재우;이종수;최한슬;정석진
    • Korean Chemical Engineering Research
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    • 제51권4호
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    • pp.432-437
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    • 2013
  • 고분자 전해질 연료전지 구동 시 양극 활성 물질에 대한 CO 피독을 방지하기 위해 Cu를 촉매 활성 종으로 사용하고 반응물의 확산이 용이한 몇 가지 메조 세공 물질을 지지체로 이용하여 CO 선택적 산화 반응(PROX반응)을 실시하였다. 그 결과 거대 세공을 가진 SBA-15를 지지체로 사용했을 때 우수한 CO 산화 활성을 보였으며 특히 Cu 담지 량에 비례하여 활성은 증가하였다. 또한 Cu의 분산도를 높이고자 첨가한 Ti 성분은 저온에서 CO 산화 성능을 높이는데 기여하였다. 특히 Ti 성분을 20 wt-% 첨가한 Cu/Ti20-SBA-15 촉매에서 Cu의 분산도가 가장 우수하였으며 CO 산화활성 역시 개선됨을 확인하였다.

역확산을 고려한 이원합금의 비평형 수지상응고 해석 (Analysis on the non-equilibrium dendritic solidification of a binary alloy with back diffusion)

  • 정재동;유호선;이준식
    • 대한기계학회논문집B
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    • 제20권10호
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    • pp.3361-3370
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    • 1996
  • Micro-Macro approach is conducted for the mixture solidification to handle the closely linked phenomena of microscopic solute redistribution and macroscopic solidification behavior. For this purpose, present work combines the efficiency of mixture theory for macro part and the capability of microscopic analysis of two-phase model for micro part. The micro part of present study is verified by comparison with experiment of Al-4.9 mass% Cu alloy. The effect of back diffusion on the macroscopic variables such as temperature and liquid concentration, is appreciable. The effect, however, is considerable on the mixture concentration and eutectic fraction which are indices of macro and micro segregation, respectively. According to the diffusion time, the behavior near the cooling wall where relatively rapid solidification permits short solutal diffusion time, approaches Scheil equation limit and inner part approaches lever rule limit.

황산구리/치오요소 처리에 의한 습윤견뢰도 증진에 관한 연구(III) (A Study on Improvment of Washing Fastness by Treatment with Copper Sulfate/Thiourea(III))

  • 윤정임;김경환
    • 한국염색가공학회지
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    • 제7권1호
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    • pp.72-79
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    • 1995
  • The effect of copper sulfate/thiourea on the diffusion and the dye exhaustion of two dyes, C. I. Acid Orange 7 and C. I. Food Yellow 3 in nylon 6 fiber has been studied. The results obtained from the experimetal are as follows : 1) Copper sulfate reacted with thiourea at constant temperature and then generated the colorless trasparent coordination compound, and then combinated end group of carboxyl of nylon 6 fiber. 2) The coordination compound [$Cu_{2}$($TU_{6}$)] ($(SO_{4})_2$) is conducted at pH 5-6 in solution intensity and repulsed the sulfonic acid group of dyes, and therefore the diffusion of dyes is restraint. 3) Dye uptake and diffusion coefficient were decreased in the order of untreated > copper sulfate/thiourea-treated > tannin-treated.

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메탄 대향류 확산화염내 수소를 첨가한 탄소나노물질 합성에 관한 연구 (Study on synthesis of carbon nanomaterials by hydrogen mixing in counterflow methane diffusion flames)

  • 신우중;최정식;윤석훈;이현식;최재혁
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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    • pp.88-89
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    • 2011
  • The study on synthesis of carbon nanomaterials by H2 mixing in counterflow methane diffusion flames has been experimentally conducted. We have also investigated on effect of catalyst and temperature in flame. The counterflow flame was formed by many kind of gas (fuel side using $CH_4-H_2-N_2$ and oxidizer side $N_2-O_2$) and nitrogen shields discharge on each other side to cut off oxidizer of the atmosphere. Ferrocene was used as a metal catalyst for CNTs synthesis. substrate was used to deposit carbon nanomaterials and these were analyzed by FE-SEM. We could find that carbon nanotubes and many kind of carbon nano materials were formed in Cu wire substrate, through this experiment.

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임게전류밀도 향상을 위한 Cu/NbTi다층박막과 초전도 선재에서의 계면반응 (Interfacial reactions in Cu/NbTi multilayer thin films and superconducting wires)

  • 심재엽;백홍구;하동우;오상수;류강식
    • E2M - 전기 전자와 첨단 소재
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    • 제8권4호
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    • pp.478-486
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    • 1995
  • Cu/NbTi multilayer thin films and superconducting wires were fabricated and heat treated with conventional annealing and analyzed by differential scanning calorimetry (DSC) as a basic study for the enhancement of Jc. Interfacial reactions of Cu/NbTi multilayer thin films and superconducting wires were investigated with optical microscope, SEM, and XRD. According to the effective heat of formation (EHF) model, CU$\_$3/Ti was predicted as a first phase. However, considering the crystalline structure and thermodynamics, CuTi was predicted as a first phase. According to the results of DSC and XRD, CU$\_$2/Ti was found to be the first phase, followed by the formation Of CU$\_$4/Ti. The difference in first crystalline phase between the experimental result and the predicted one was discussed. In case of Cu/NbTi superconducting wires, the compounds formed at the Cu/NbTi interface grew with annealing time and the amount of compounds formed in Nb-47wt%Ti alloy was larger than that in Nb-50wt%Ti alloy. It seemed that the incubation time for the formation of compounds in Nb-50wt%Ti alloy was longer than that formed in Nb-47wt%Ti alloy. Also, the diffusion was the rate controlling step for the growth of compounds in all specimens. These compounds were formed at 500-600.deg. C for I hour annealing and, thus, the drawing time below I hour must be required to minimize the growth of compounds for the enhancement of Jc.

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The Effects of UBM and SnAgCu Solder on Drop Impact Reliability of Wafer Level Package

  • Kim, Hyun-Ho;Kim, Do-Hyung;Kim, Jong-Bin;Kim, Hee-Jin;Ahn, Jae-Ung;Kang, In-Soo;Lee, Jun-Kyu;Ahn, Hyo-Sok;Kim, Sung-Dong
    • 마이크로전자및패키징학회지
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    • 제17권3호
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    • pp.65-69
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    • 2010
  • In this study, we investigated the effects of UBM(Under Bump Metallization) and solder composition on the drop impact reliability of wafer level packaging. Fan-in type WLP chips were prepared with different solder ball composition (Sn3.0Ag0.5Cu, and Sn1.0Ag0.5Cu) and UBM (Cu 10 ${\mu}m$, Cu 5 ${\mu}m$\Ni 3 ${\mu}m$). Drop test was performed up to 200 cycles with 1500G acceleration according to JESD22-B111. Cu\Ni UBM showed better drop performance than Cu UBM, which could be attributed to suppression of IMC formation by Ni diffusion barrier. SAC105 was slightly better than SAC305 in terms of MTTF. Drop failure occurred at board side for Cu UBM and chip side for Cu\Ni UBM, independent of solder composition. Corner and center chip position on the board were found to have the shortest drop lifetime due to stress waves generated from impact.