• 자원리싸이클링
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• 제26권5호
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• pp.3-11
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• 2017

금과 은은 귀금속으로 첨단소재를 제조하는데 사용된다. 용매추출은 다양한 침출용액으로 부터 순수한 금과 은을 회수할 수 있는 중요한 공정이다. 본 논문에서는 cyanide, thiocyanate, thiosulfate, thiourea과 염산용액에서 금(I, III)과 은(I)의 용액화학 및 용매추출에 의한 분리를 고찰했다. 여러 단독 및 혼합추출제에 의한 금(I, III)과 은(I)의 용매추출 및 분리거동을 각 침출용액에서 추출반응과 추출제의 선택도를 토대로 비교했다. 염산용액이 용매추출에 의한 금과 은의 분리의 효율측면에서 적당하다.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1832-1838
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• 2006

The present paper is focused on sorption concentration of silver (I) on some complex-forming ion exchangers in the initial thiocyanate form and subsequent determination of Ag(I) in the phase of anion exchanger AN-25 by diffuse reflectance spectroscopy. The sorption and kinetic characteristics of the sorbents were investigated. The apparent stability constants of thiocyanate silver complexes in the ion exchanger phase were calculated. The sorption-spectroscopic method is proposed for Ag(I) determination in aqueous solutions. The calibration curve is linear in the concentration range of 10-200 mg/L (sample volume is 10.0 mL) and the detection limit is 2 $\mu$g/mL. The presence of $Na^+,\;K^+,\;Mg^{2+}$ (macrocomponents) as well as of Ni (II), Co (II), Cu (II) do not hinder the determination of silver (I).

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.52.2-52.2
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• 2008

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.713-717
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• 2006

$S_2O$-donor macrocyclic isomers incorporating a xylyl group in o- ($L^1$), m- ($L^2$) and p-positions ($L^3$) extract no metal ions except silver(I) from aqueous to chloroform phase. And the magnitudes of %Ex for silver(I) are in the order of $L^1$ > $L^2$ > $L^3$. Taking this result into account, $L^1$-$L^3$ were utilized as membrane active components to prepare potentiometric silver(I)-selective electrodes. The proposed macrocycles-based electrodes E1 ($L^1$), E2 ($L^2$) and E3 ($L^3$) exhibited comparable results which show considerable selectivity toward silver(I) over alkali, alkali earth and other transition metal ions. Comparative NMR study on $L^1$-$L^3$ and their complexes with silver(I) in solution was also accomplished. In addition, a unique sandwich-type complex $[Ag(L^1)_2]CIO_4$ was prepared from the assembly reaction of $L^1$ with $AgClO_4$ and structurally characterized by an X-ray diffraction analysis.

• 자원환경지질
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• 제20권1호
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• pp.1-18
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• 1987

The Cheolam silver deposits are emplaced along the fractures in breccia dike and the Hongjesa granite. Breccia dike contains fragments of late Cretaceous acidic volcanic rocks and other fragments of various rocks distributed in the mine area. Therefore it is presumed that the mineralization was taken place in later than late Cretaceous time. Mineral paragenesis is complicated by multiple episodes of fracturing. Six distinct depositional stages can be recognized: stage I, deposition of base metal sulfides; stage II, deposition of base metal sulfides and silver minerals; stage III, deposition of carbonates; stage IV, deposition of silver minerals and base metal sulfides; stage V, deposition of silver minerals; stage VI, deposition of barren quartz. Silver minerals from the deposits are native silver, acanthite, pyrargyrite, argentian tetrahedrite, stephanite, polybasite, pearceite, allargentum, antimonial silver and electrum. Fluid inclusion studies ware carried out for stage I, II, IV and VI quartz and stage III calcite. Homogenization temperatures for each stage are as follows: stage I, from $225^{\circ}$ to $360^{\circ}C$; stage II, from $145^{\circ}$ to $220^{\circ}C$; stage III, from $175^{\circ}$ to $240^{\circ}C$; stage IV, from $130^{\circ}$ to $185^{\circ}C$; stage VI, from $120^{\circ}$ to $145^{\circ}C$. Salinities of ore fluids were in the range of 4 and 10 wt.% equivalent NaCl over stage I and stage VI. Ore mineralogical data of each stage indicate that temperatures are within the range of homogenization temperature of fluid inclusions and sulfur fugacities declined steadily from $10^{-9.7}atm$. to $10^{-18.7}atm$. through stage I into stage V.

• 대한화학회지
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• 제20권6호
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• pp.486-493
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• 1976

AgI 가루에 PVC를 섞어 Infrared Pellet Presser로 눌러 만든 Pellet을 이용하여 막전극을 만들고 이것을 지시전극으로 사용하여 $Ag^+$의 활동도에 대한 전위를 측정하였다. 이 막전극의 특성을 순수한 AgI pellet와 PVC로 표면을 입힌 AgI pellet을 이용한 두 막전극의 특성과 비교하였다. 이들 막전극의 은이온 활동도에 대한 감응은 은이온의 농도가 $10^{-1}$M에서 $10^{-6}$M 까지의 범위에서 좋은 직선을 보여준다. 그러나 그 중에서도 AgI가루에 PVC를 섞어서 만든 막전극이 Nernstian 기울기에 가장 잘 맞고 견고하고 장시간 사용할 수 있어 가장 우수함을 알 수 있었다. 이 전극은 은이온 이와의 다른 양이온에 대하여는 거의 감응하지 않고 할로겐화이온, 즉$I^-,CI^-,Br^-,CN^-$에 대한 감응도는 $10^{-1}$M에서 $10^{-6}$M까지 직선관계를 유지하였다. 이 전극은 단일 할로겐화이온 뿐 아니라 할로겐화이온의 혼합시료 용액의 전위차 은법적정에 지시전극으로 이용될 수 있음을 알았다.

• 자원환경지질
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• 제21권4호
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• pp.367-380
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• 1988

Most of the gold (-silver) vein deposits at Yeongdong District are mainly distributed in the precambrian metamorphic rocks. Based on the Ag/Au total production and ore grade ratios, the chemical composition of electrum and the associated sulfides, the gold(-silver) deposits at Yeongdong District may be classified into 4 classes: pyrrhotite - type gold deposits( I), pyrite - type gold deposits (IT A; massive vein), pyrite - type gold deposits (II B; nonmassive vein) and argentite - type gold - silver deposits(III). The chemical study on electrum(including native gold) revealed that Au content (2.8 to 92.4 atomic%) of electrums varies very widely for different classes of deposits. The Au content of electrum associated with pyrrhotite (Class I), ranging from 47.1 to 92.4 atomic% Au, is clearly higher than that associated with pyrite (Classes IIA, IIB and III). In contrast, classes I, II, and III deposits do not show clear differences in Au content of electrum. In general, pyrrhotite - type gold deposits(I) are characterized by features such as simply massive vein morphology, low values in the Ag/Au total production and ore grade ratios, the absence or rarity of silver - bearing minerals except electrum, and distinctively simple mineralogy. Although the geological and mineralogical features and vein morphology of pyrite - type gold deposits(IIA)are very similar to those of pyrrhotite - type gold deposits (I), Class II A deposits reveal significant differences in the associated iron sulfide (i. e. pyrite) with electrum and Au content of electrum. The Ag/Au total production and ore grade ratios from Class II A deposits are relatively slightly higher than those from Class I deposits. Pyrite - type gold deposits(II B) and argentite - type gold - silver deposits (III) have many common features; complex vein morphology, medium to high values in the Ag/Au total production and ore grade ratios and the associated iron sulfide (i. e. pyrite). In contrast to Class II B deposits, Class III deposits have significantly high Ag/Au total production and ore grade ratios. It indicates distinct difference in the abundance of silver minerals (i. e. native silver and argentite). The fluid inclusion analyses and mineralogical data of electrum tarnish method indicate that the gold mineralization of Classes I and II A deposits was deposited at temperatures between $230^{\circ}$ and $370^{\circ}C$, whereas the gold (-silver) mineralization of Classes ITB and ill formed from the temperature range of $150^{\circ}-290^{\circ}C$. Therefore, Classes I and IT A deposits have been formed at higher temperature condition and/or deeper positions than Classes IIB and III.

• 전기화학회지
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• 제8권1호
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• pp.17-23
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• 2005

$Bi_2O_3$를 첨가한 8M KOH용액에서 다결정 Ag전극의 전기화학적인 거동과 생성된 산화물들의 미세조직 변화를 분석하였다. $Bi_2O_3$를 첨가한 8M KOH용액에서 Ag 산화물뿐만 아니라 새로운 Ag-Bi-O화합물들이 생성되는 것을 알 수 있었다. Ag(I) 산화물 생성 전위 영역에서는 $Ag_2O$ 이외에, Ag-Bi-O 화합물이 핵 생성과 3D성장 과정에 의해서 생성되고, Ag(II)산화물 생성 전위 영역에서는 AgO뿐만 아니라 새로운 Ag-Bi-O화합물들이 핵 생성과 3D성장 과정에 의해서 생성되었다. Ag(I) 산화물 생성 전위에서 두 가지 형상의 Ag(I) 산화물이 생성되는 것을 SEM 조직에 의해 관찰하였다.

• 대한화학회지
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• 제47권1호
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• pp.26-30
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• 2003

이핵 화합물, $Ag_2$[Phen]_2[S_2P(OPr)_2]_2$(Phen=1,10-phenanthroline; Pr=propyl)은 비스(디프로필디싸이오포스페이토) 은(|)화합물과 1,10 펜안트로린 리간드 반응에 의하여 합성되었고, 그 화합물 구조는 X-ray에 의하여 규명되었다. 두 디프로필디싸이오포스페이토 리간드는 두 개의 은 원자를 연결하여 팔각형 $Ag_2S_4P_2$ 고리를 형성하였고, 1,10-펜안트로린 리간드는 은 이온과 결합하여 사면체구조를 이루었다. Ag-S 결합거리는 2.471(1)와 2.567(1) ${\AA}$이었고, Ag-N 결합 거리는 2.3666(3)와 2.471(3) ${\AA}$이었다.

• 자원환경지질
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• 제21권3호
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• pp.287-307
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• 1988

The Cheongju gold-silver mine is located at approximately $36^{\circ}28^{\prime}$north latitude and $127^{\circ}31^{\prime}$ east longitude in the Cheongju City of the Chung cheong bug Do, South Korea. Gold-Silver bearing hydrothermal quartz veins, occur in Cheongju Granit of Jurassic age. K-Ar isotope data for sericite in quartz vein indicate that the Au-Ag mineralization took place in early Cretaceous ($97.5{\pm}2.18$ MA. Park, et ai, 1986). Three stage of mineralization recognized anre, from early to later, (I) Sulide stage: pyrite, arsenopyrite, pyrrhotite (Hpo), sphalerite, chalcopyrite, electrum and quartz (II) Electrum stage: pyrite, sphalerite, galena, chalcopyrite, electrum and quartz. (III) Silver mineral stage: pyrite, marcasite, pyrrhotite (Mpo), sphalerite, galena, electrum, native silver argentite, fluorite, calcite and quartz. In this paper, mode of occurrences and chemical compositions of electum and native silver have been investigated by means of microscope and EPMA. Electron probe microanalysis shows that an individual grain of electrum is almost homogeneous in composition. Silver content of electrum ranges from 44.7-67.1 atom.%. Gold content of native silver ranges below 0.2 atom. %. Vicker's hardness number (VHN) of electrum and native silver ranges $78.2-81.8kg/mm^{2}$ respectively. The filling temperature of fluid inclusions in quartz ranges from $130-280^{\circ}C$. On the basis of arsenpyrite geothemometer, the equilibrium temperature and sulfur fugacity of the pyrite-arsenopyrite-pyrrhotite(Hpo) assemblage is assumed to be in ange from $300-310^{\circ}C$ and $10^{-10}$ to $10^{-11}$ atm. The estimated ore reserviors on Cheongju mine area are calculated to 8000 T/M, averaing 8.6g/t Au, 27.8 g/t Ag, 1.25% Pb, l.65% Zn.