• Economic and Environmental Geology
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• v.19 no.4
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• pp.243-264
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• 1986

This work is a metallogeny on gold-silver deposits in South Korea based on the close examination of the author's own data and a broad review of existing literature available. The metallogenic epochs in Korea are temporarily connected with the history of tectonism and igneous activities, and are identified as the Precambrian, Paleozoic, Jurassic to early Cretaceous, late Cretaceous to early Tertiary, and Quaternary epochs, whereas the metallogenic provinces are spatially associated with some of the felsic to intermediate igneous rocks, lacking mineralization related to basic and ultrabasic rocks. The metallogeny on the gold-silver deposits is mostly related to the granitic rocks intrusives. Epigenetic gold-silver mineralization in South Korea ranges in metallogenic epochs from Precambrian through Triassic, Jurassic and Cretaceous to Eocene (?), in genetic types from hypothermal through mesothermal and epithermal quartz-sulfide veins to volcanogenic stockworks, with some disseminated types. Reporting on metallic association from gold without silver, gold-silver, silver-gold, silver without gold, and gold or silver as a by-product from other metallic ores. The most representative genetic types and metal associations of gold-silver deposits are hydrothermal quartz veins associated with the Daebo and Bulgugsa granitic magmatism. The most closely associated paragenetic metallic minerals in gold-silver hydrothermal quartz-sulfide vein type deposits are: copper, lead, zinc, pyrite and arsenopyrite. More than 560 gold-silver mines are plotted in the distribution map grouped within the 10 different metallogenic provinces of South Korea. Specific mineralizations with related mineral association in both sulfides and gangues observed selected from 18 Korean and 8 Japanese Au-Ag deposits. The 7 selected individual gold-silver mines representing specific mineralization types are described in this report.

• Resources Recycling
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• v.3 no.2
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• pp.17-23
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• 1994

The dissolution of gold and silver from concentrate was studied with acidic thiourea solution. The results showed that the gold and silver extraction was severely affected by concentration of thiourea and oxidant, pulp density, etc. Especially, oxidant such as ferric ions enhanced the leching rate of gold and silver. High concentration of ferric ions, however, dissolved the sulfide ore to form electrochemically passive layer on the surface of ore particles, which caused the precious metal not to be leached out from the ore. The use of $SO_2$could not effectively enhance the recovery of precious metal but reduce to some extent the consumption of thiourea. The leaching of gold and silver was achieved with recovery more than 90% and 80%, respectively, under the following conditions; Thiourea conc. :0.4M Oxidant : None $H_2SO_4$ conc. : 0.5M Pulp density : <10% Leaching time :4 Hrs Potential :250mV The Thiourea was consumed about 10% in comparison with its initial concentration.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.279-287
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• 1995

This study examined the anti-cancer effects of diallyl sulfide(DAS) and/or diallyl disulfide(DDS), major components of garlic oil, with the DEN-PH model in rats, by the numbers and areas per cm$^2$ of induced glutathion S-transferase placental form(GST-P) positive foci and silver-stained nucleolar organizer regions(Ag-NORs) counts per nuclei in liver as indicator. Sprague-Dawley(SD) rats were given the diethylnitrosamine(DEN, 200 mg/kg, i.p.) as initiator and 2 weeks later, in experiment 1, rats were treated with DAS(200 mg/kg, i.g.) and/or DDS(50 mg/kg, i.g.) for 6 weeks, respectively and concomitantly and also were given the same dose of DAS and/or DDS prior to DEN treatment for 2 weeks, and in experiment II, rats were treated with potential cancer promoter, 2-acetylaminofluorene (2-AAF, 20 mg/kg, i.g.). The DAS and/or DDS were treated prior to 2-AAF for 8 weeks, respectively and concomitantly. Then the anti-promoting effects of DAS and/or DDS were assessed. All rats were subjected to the two-thirds partial hepatectomy(PH) at week 3 and sacrificed at week 8. In experiment I, DAS and/or DDS treatment only prior to DEN showed inhibition of the development of GST-P positive foci. In experiment II, DAS and/or DDS treatment prior to 2-AAF promotion showed obvious inhibition of the development of GST-P positive foci in numbers and areas and AgNORs counts. In conclusion, We found DAS and/or DDS had the preventive effects on the hepatocarcinogenesis in rats and the concomitant treatment had some additive effects compared with the each treatment and AgNORs counts correlated well with the preneoplastic hepatic lesion.

• Journal of the Korean earth science society
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• v.25 no.6
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• pp.484-494
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• 2004

The Soowang Au-Ag deposits occur as quartz veins which filled fissures in middle Cretaceous porphyritic granite an/or gneiss of the Precambrian Sobaegsan gneiss complex. The paragenetic studies suggest that vein filling can be divided into four identifiable stages (I to IV). Stage I is the main sulfide stage, characterized by the deposition of base-metal sulfide and minor electrum. Stage II is the electrum stage, whereas stage III represents a period of the deposition of silver-bearing sulfosalts and minor electrum. Stage IV is the post ore stage. Mineralogical and fluid inclusion evidences suggest that mineralization of the Soowang deposits were deposited by the cooling of the fluids from initial high temperatures 300$^{\circ}C$ to later low temperatures 150$^{\circ}C$. The salinity of the fluids were moderate, ranging from 10.4wt.% equivalent NaCl in sphalerite to 3.1wt.% equivalent NaCl in barite. The gold-silver mineralization of the Soowang mine occurred at temperatures between 140 and 250$^{\circ}C$ from fluids with log $fs_2$ from -12 to -18 atm. A consideration of the pressure regime during ore deposition, based on the fluid inclusion evidence of boiling, suggests lithostatic pressure of less than 210 bars. This pressure condition indicates that vein system of the Soowang deposit formed at depth around 800 m below the surface at the time of gold-silver mineralization.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.1-6
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• 2007

A silver indium sulfide ($AgInS_{2}$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the literature. The grown $AgInS_{2}$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-to-band transition. The valence band splitting of $AgInS_{2}$ was investigated by means of the photocurrent measurement. The crystal field splitting, ${\Delta}cr$, and the spin orbit splitting, ${\Delta}so$, have been obtained to be 0.150 eV and 0.009 eV at 10 K, respectively. And, the energy band gap at room temperature has been determined to be 1.868 eV. Also, the temperature dependence of the energy band gap, $E_{g}$(T), was determined.

• Economic and Environmental Geology
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• v.29 no.2
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• pp.119-127
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• 1996

Electrum-sulfide minerals of the Namsan Au-Ag mine were deposited in two stages of quartz and calcite veins that fill fault planes in Mesozoic granitic rocks (230~155 Ma). The K/Ar radiometric dating of hydrothermal sericite indicates that mineralization is early Cretaceous age ($127{\pm}3.0Ma$). Mineralogic, fluid inclusion and sulfur isotopic data show that ore minerals were deposited at temperatures between $340^{\circ}C$ and $200^{\circ}C$ from fluid with salinities of 3 to 6 equiv. wt % NaCl. Evidence of fluid boiling (and $CO_2$ effervescence) indicates a maximum pressures of 100 bars. The formation temperature and $fs_2$, of Au-mineralization from the Namsan mines are mainly $280{\sim}230^{\circ}C$ and $10^{-11}{\sim}10^{-13}$ atm, respectively. Au deposition was likely a result of boiling caused to chemical change (pH, $f_{O2}$, ${\Sigma}_{H_2S{\cdot}{\cdot}}$) of ore-fluids. Sulfur isotope composition of sulfide minerals (${\delta}^{34}S=5.1$ to 8.2‰) are consistent with ${\delta}^{34}S_{{\Sigma}{H2S}}$ value of +6 to +7‰, suggesting an igneous source of sulfur partially mixed with wall-rock sulfur.

• Economic and Environmental Geology
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• v.46 no.1
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• pp.21-28
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• 2013

In order to optimize gold leaching from refractory sulfide concentrate, a HCl-NaClO-$FeCl_3$ solution with varying attributes was applied to the roasted concentrate from Uil mine. The gold from Uil mine occurs in the form of invisible gold that is difficult to leach. The results of the gold leaching experiments showed that the best gold leaching parameters were $550^{\circ}C$ of roasting temperature, 2.0 M of concentration, 1.0% of pulp density, and $70^{\circ}C$ of leaching temperature. It is confirmed that the HCl-NaClO-$FeCl_3$ solution was an environmentally friendly method to leach gold and silver from the refractory sulfide concentrate as an alternative lixiviant to cyanide.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.424-425
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• 2006

Zinc sulfide is a well-known host material of phosphor emitting different radiations dependent on different doping impurities of metallic ion. It emits green, blue, orange-yellow or white colors by doping with activators such as copper, silver, manganese and so on. In this study, manganese, copper and chlorine doped ZnS phosphor (ZnS:Mn,Cu,Cl) was synthesized by solid-state reaction method. The optical properties were investigated according to different concentrations of sulfur and activators used during the synthesis process.

• Economic and Environmental Geology
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• v.35 no.4
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• pp.299-316
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• 2002

The Samkwang gold-silver deposits consist of gold-silver-bearing hydrothermal massive quartz veins which filled the fractures along fault shear (NE, NW) zones within Precambrian banded or granitic gneiss of Gyeonggi massif. Ore mineralization of this deposits occurred within a single stage of quartz vein which was formed by multiple episodes of fracturing and healing. Based on vein mineralogy and paragenesis, massive quartz veins are divided into two main paragenetic stages which are separated by a major faulting event. Main ore mineralization occurred at stage I. Wall-rock alteration from this deposits occur as mainly sericitization, chloritization, silicification and minor amounts of pyritization, carbonitization, propylitization and argillitization. Ore minerals are composed mainly of arsenopyrite (29.21-32.24 As atomic %), pyrite, sphalerite (6.45-13.82 FeS mole %), chalcopyrite, galena with minor amounts of pyrrhotite, marcasite, electmm (39.98-66.82 Au atomic %) and argentite. Systematic studies of fluid inclusions in early quartz veins and microcracks indicate two contrasting physical-chemical conditions: 1). temperature (215-345$^{\circ}$C) and pressure (1296-2022 bar) event with $H_{2}O-CO_{2}-CH_{4}-NaCl$fluids (0.8-6.3 wt. %) related to the early sulfide deposition, 2). temperature (203-441$^{\circ}$C) and pressure (320 bar) event with $H2_{O}$-NaCI $\pm$ $CO_{2}$ fluids (5.7-8.8 wt. %) related to the late sulfide and electrum assemblage. The H20-NaCI $\pm$ $CO_{2}$ fluids represent fluids evolved through fluid unmixing of an $H_{2}O-CO_{2}-CH_{4}-NaCl$fluids due to decreases in fluid pressure and influenced of deepcirculated meteoric waters possibly related to uplift and unloading of the mineralizing suites. Calculated sulfur isotope compositions (${\delta}^{34}S_{fluid}$) of hydrothermal fluids (1.8-4.9$\textperthousand$) indicate that ore sulfur was derived from an igneous source. Measured and calculated oxygen and hydrogen isotope compositions (${\delta}^{18}O_{I120}$, ${\delta}D$) of ore fluids (-5.9~10.9$\textperthousand$, -102~-87$\textperthousand$) indicate that mesothermal auriferous fluids at Samkwang gold-silver deposits were likely mixtures of $H_{2}O$-rich, isotopically less evolved meteoric water and magmatic fluids.

• Journal of Conservation Science
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• v.38 no.2
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• pp.124-132
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• 2022

Through scientific analysis, this study identified the material characteristics of metal foil decorating the border line and knotting of the National Folklore Cultural Heritage 'Pouch for the Sutra Embroidered with a Sun and Moon Design'. Through Scanning Electron Microscope-Energy Dispersive Spectroscopy results, it was estimated that silver (Ag) and sulfur (S) were present in the metal foil, and silver leaf was also attached to the medium. S may discolor Ag from yellow to black depending on its concsentration and contact time. Yellow color could not be identified in metal foil at present. But there existed an example of the preparation of a gold-colored flat silver thread; therefore, further research is needed to estimate the original color. The lamella was reddish brown on the back. Aluminum, silicon, and iron were also detected and were the main components found in red soil. This is believed to be the red adhesive in traditional flat gold thread and is considered to be an adhesive-related component of the metal foil. From the gas chromatography mass spectrometry results, the adhesive component was confirmed to be animal glue.