• Title/Summary/Keyword: iron mineral

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An Alysisan Experimental Study on the Evaluation Method of Clay Mineral Content through Aggregate Composition Analysis (골재의 성분분석을 통한 토분함량 평가방법에 관한 실험적 연구)

  • Kim, In;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.5
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    • pp.565-575
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    • 2024
  • This research was initiated to establish quality standards and testing methods for fine dust in aggregates, a component currently not regulated under the Korean Industrial Standards(KS) KS F 2527 for Concrete Aggregates. With limited existing research and no definitive quality or testing standards for fine dust, this study sought to provide a quantitative analysis of fine dust in aggregates and to set forth quality standards based on the dust content through a concrete performance evaluation. The experimental findings showed that the primary chemical constituents of the fine dust were aluminum oxide(Al2O3), iron oxide(Fe2O3), and silicon dioxide(SiO2). It was observed that increasing levels of fine dust in the aggregates led to higher values of the fine dust index(Al2O3+Fe2O3). This escalation in the fine dust index corresponded with an increase in the unit water content of the concrete and a consequent decline in compressive strength. Based on these observations, a maximum allowable limit for the fine dust index in aggregates was proposed at 23%. This limit was derived from the correlation between fine dust content and a 15% reduction in compressive strength of standard concrete specimens. The proposed evaluation method for the fine dust index based on its content in aggregates is expected to enhance concrete performance and ensure structural stability. This contribution to the field addresses a significant gap in the standards and provides a foundation for further research and standardization in the construction materials industry.

Genetic Environments of Hydrothermal Vein Deposits in the Pacitan District, East Java, Indonesia (인도네시아 동부자바 빠찌딴(Pacitan) 광화대 열수 맥상 광상의 성인 연구)

  • Choi, Seon-Gyu;So, Chil-Sup;Choi, Sang-Hoon;Han, Jin-Kyun
    • Economic and Environmental Geology
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    • v.28 no.2
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    • pp.109-121
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    • 1995
  • The hydrothermal vein type deposits which comprise the Kasihan, Jompong and Gempol mineralized areas are primarily copper and zinc deposits, but they are also associated with lead and/or gold mineralization. The deposits occur within the Tertiary sedimentary and volcanic rocks in the Southern Mountain zone of the eastern Java island, Indonesia. Mineralization can be separated into two or three distinct stages (pre-and/or post- ore mineralization stages and main ore mineralization stage) which took place mainly along pre-existing fault breccia zones. The main phase of mineralization (the main ore stage) can be usually classified into three substages (early, middle and late) according to ore mineral assemblages, paragenesis, textures and their chemical compositions. Ore mineralogy and paragenesis of the three areas in the district are different from each other. Pyrite, pyrrhotite (/arsenopyrite), iron-rich (up to 20.5 mole % FeS) sphalerite and (Cu-)Pb-Bi sulfosalts are characteristic of the deposits in the Kasihan (/Jompong) area. On the other hand, pyrite + hematite + magnetite + iron-poor (2.7 to 3.6 mole % FeS) sphalerite assemblage is restricted to the Gempol area. Fluid inclusion data suggest that fluids of the main ore stage evolved from initial high temperatures (near $350^{\circ}C$) to later lower temperatures (near $200^{\circ}C$) with salinities ranging from 0.8 to 10.1 equiv. wt. percent NaCl. Each area represents a separate hydrothermal system: the mineralization at Kasihan and Jompong were largely due to early fluid boiling coupled with later cooling and dilution, whereas the mineralization at Gempol was mainly resulted from cooling and dilution by an influx of cooler meteoric waters. Fluid inclusion evidence of boiling indicates that pressures of ${\geq}95$ to 255 bars (${\geq}95$ bars for the Gempol area: $\approx$ 120 to 170 bars for the Jompong area: $\approx$ 140 to 255 bars for the Kasihan area) during portions of main ore stage mineralization. Equilibrium thermodynamic interpretation indicates that the evolution trends of the temperature versus fS2 variation of ore stage fluids in the Pacitan district follow two fashions: ore fluids at Kasihan and Jompong changed from the pyrite-pyrrhotite sulfidation stage towards pyritehematite- magnetite state, whereas those at Gempol evolved nearly along pyrite-hematite-magnetite reaction curve with decreasing temperature. The sulfur isotope compositions of sulfide minerals are consistent with an igneous source of sulfur with a ${\delta}^{34}S_{{\Sigma}s}$ value of about 3.3 per mil. The oxygen and hydrogen isotopic compositions of the fluids in each area indicate a progressive shift from the dominance of highly exchanged meteoric water at early hydrothermal systems towards an un- or less-exchanged meteoric water at later hydrothermal systems.

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Dietary Intakes, Serum Concentrations, and Urinary Excretions of Fe, Zn, Cu, Mn, Se, Mo, and Cr of Korean Young Adult Women (일부 젊은 성인여자의 Fe, Zn, Cu, Mn, Se, Mo 및 Cr의 식사섭취, 혈청농도 및 소변배설)

  • Kim, Kyune-Hee;Lim, Hyeon-Sook
    • Journal of Nutrition and Health
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    • v.39 no.8
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    • pp.762-772
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    • 2006
  • This study was conducted to investigate dietary intakes, serum concentrations, and urinary excretions of iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), selenium (Se), molybdenum (Mo), and chromium (Cr) of Korean young adult women. A total of 19 apparently healthy young adult women aged in their twenties or thirties participated voluntarily. One-tenth of all foods they consumed for 3 consecutive days were collected, all urine excreted for the same 3 days was gathered, and fasting venous blood was withdrawn for the trace mineral analyses. Of the food, blood, and urine samples, the contents of Zn, Cu, Mn, Se, Mo, and Cr were analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS) and that of Fe by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) after wet digestion. The intake of Fe, $6.94{\pm}2.18mg$, did not meet the estimated average requirement (EAR) for Korean women aged 20-29 years old. On the contrary, the intakes of Zn ($9.35{\pm}4.95mg$), Cu ($1.18{\pm}0.26mg$), and Mn ($3.69{\pm}0.69mg$) were sufficient for each respective EAR. However, some of the subjects did not take the EAR for Zn. The Se intake, $41.93{\pm}9.28{\mu}g$, however, was almost similar to the EAR for Se. Although there are no references for Mo and Cr, the intakes of these minerals ($134.0{\pm}49.1\;and\;136.5{\pm}147.9{\mu}g$, respectively) seemed to be excessively sufficient. Serum Fe concentration, $88.7{\pm}36.8{\mu}g/dL$, seemed to be a little bit lower than its reference median but within its normal range. Approximately one-fourth of the subjects were in anemic determined by Hb and Hct and below the deficiency serum level of Fe, $60{\mu}g/dL$. In addition, serum Se concentration, $3.73{\pm}0.60{\mu}g/dL$, was also below its reference median and normal range. However, serum concentrations of Zn ($99.6{\pm}30.6{\mu}g/dL$) and Mo ($0.25{\pm}0.10{\mu}g/dL$) were fairly good compared to each reference median. The status of Cu could be determined as good although its serum concentration ($91.6{\pm}14.6{\mu}g/dL$) was slightly below its reference median. Since there are no decisive reference values, it was not easy to evaluate serum concentrations of Mn ($0.93{\pm}0.85{\mu}g/dL$) and Cr ($8.60{\pm}7.25{\mu}g/dL$). But Mn and Cr status seemed to be adequate. Urinary Fe excretion, $4.48{\pm}1.98{\mu}g/dL$, was pretty much lower than its reference and that of Se, $2.45{\pm}1.17{\mu}g/dL$, was also lower than its average. On the other hand, those of Zn ($42.95{\pm}20.47{\mu}g/dL$) and Cu ($5.68{\pm}1.50{\mu}g/dL$) were flirty good. In case of Mn, urinary excretion, $0.31{\pm}0.09{\mu}g/dL$, was much greater than its reference. Urinary excretions of Mo ($7.48{\pm}2.95{\mu}g/dL$) and Cr ($1.37{\pm}0.41{\mu}g/dL$) were very higher compared to each reference. The results of this study revealed that Korean young adult women were considerably poor in Fe status, a bit inadequate in Se status, partly inadequate in Zn status, and flirty good in Cu, Mn, Mo and Cr status. However, there was a problem of excessive intakes of Mo and Cr. It, therefore, should be concerned to increase the intakes of Fe, Se and Zn but to decrease Mo and Cr consumption for young adult women.

A Study on the Relationship between Milk Consumption, Dietary Nutrient Intake and Physical Strength of Adolescents in Middle and Small-Sized Cities in Korea for Dietary Education of Home Economics Subject at Middle and High Schools (중등학교 가정교과 식생활교육을 위한 청소년의 우유 섭취, 영양 섭취 및 체력과의 관계 연구)

  • Kim, Sun-Hyo
    • Journal of Korean Home Economics Education Association
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    • v.28 no.4
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    • pp.159-167
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    • 2016
  • This study was performed to investigate the relationship between milk consumption, dietary nutrient intake, and physical strength in Korean adolescents for dietary education of home economics subject at middle and high schools. Intake of milk and milk products, that of dietary nutrients, and physical strength records were surveyed for 298 high school students resided in small and medium-sized cities in Korea. Intake of milk and milk products was collected from three-day dietary survey, and daily dairy equivalent of calcium was calculated by dividing daily calcium intake(mg) from milk and milk products by calcium content(200 mg) of 200 mL milk. Dietary survey was performed during three days including two-weekdays and one-weekend by food record method. Dietary nutrient intake was analyzed by CAN-Pro 3.0. Physical strength records were offered from subjects' schools. Subjects were divided into low intake group(${\leq}0.29/d$), medium intake group(0.30-0.78/d) and high intake group(0.79-5.66/d) according to daily mean dairy equivalent of calcium taken by them, and most of them consumed milk and milk products less than '2' of the recommended value. Daily mean dairy equivalent of calcium was significantly related with high records of '50 m running' and 'stand long jump'(p<0.05), however it was not related with other records of physical strength. Intakes of energy, carbohydrate, protein, fat, calcium, phosphorus, iron, zinc, thiamin, riboflavin, niacin and vitamin E were significantly correlated with high record of '50 m running'(p<0.01). Intakes of nutrients were related with '50 m running' except fat were significantly correlated with high record of 'stand long jump'(p<0.05). Intakes of protein, phosphorus, iron, zinc, vitamin A, $B_6$ and E were significantly correlated with high record of 'long distance running'(p<0.05). In conclusion intake of milk and milk products was related with physical strength records('50 m running' and 'stand long jump') and intakes of most nutrients including energy nutrient, vitamin and mineral were correlated with physical strength records('50 m running', 'stand long jump' and 'long distance running') in Korean adolescents. Therefore, optimal consumption of milk and various nutrients for balanced nutrition during adolescents should be emphasized in dietary education of home economics subject for their strong physical strength.

Comparison of Nutritional Compositions of Green Vegetables (나물의 영양성분 비교)

  • Jin, Yong-Xie;Kim, Hyeon-Young;Kim, Se-Na;Lee, Ji-Yoon;Seo, Dongwon;Choi, Youngmin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.5
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    • pp.592-599
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    • 2017
  • This study examined the nutritional compositions of seven raw and blanched green vegetables: Amaranthus mangostanus L. (AM), Aster scaber Thunberg, Taraxacum platycarpum H. Dahlstedt (TP), Oenanthe javanica (Blume) DC, Allium tuberosum Rottler, Ligularia fischeri (Ledeb.) Turcz (LF), and Euonymus alatus (Thunb.) Siebold (EA). Proximate compositions (moisture, protein, ash, dietary fiber, and fat), minerals (calcium, phosphorus, iron, potassium, sodium, and magnesium), and vitamins (riboflavin and vitamin C) were analyzed in the study. In this study, moisture contents of raw and blanched green vegetables were 71.28~92.68 g/100 g and 76.90~92.09 g/100 g, respectively. The protein and fat contents of raw LF (33.38 g/100 g and 4.50 g/100 g dry weight basis, respectively) were higher than those of other cultivars. Ash contents of AM were significantly higher than those of their respective raw samples. Potassium, magnesium, calcium, and sodium contents of AM were 7,710.63 mg/100 g, 1,786.67 mg/100 g, 1,534.44 mg/100 g, and 743.18 mg/100 g, respectively. In the case of raw green vegetables, iron content of TP was 55.23 mg/100 g, which was the highest value among tested green vegetables. Total dietary fiber content of EA was 59.75 g/100 g, which was the highest value. Riboflavin content was highest in the raw and blanched LF (3.10 mg/100 g and 3.05 mg/100 g, respectively). Vitamin C contents of raw and blanched EA were 468.28 mg/100 g and 471.42 mg/100 g, respectively, which were higher than the other values. There were differences in nutritional ingredients according to different types of green vegetables. Therefore, it is advisable to evenly ingest various green vegetables.

A Mineralogical Study on the Arsenic Behavior in the Tailings of Nakdong Mine (낙동광산의 광미 내 비소 거동에 대한 광물학적 연구)

  • Lee, Woo-Chun;Cho, Hyen-Goo;Kim, Young-Ho;Kim, Soon-Oh
    • Journal of the Mineralogical Society of Korea
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    • v.22 no.4
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    • pp.359-370
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    • 2009
  • Arsenic and heavy metals leached out as a result of oxidation of tailings exposed to the surface pose a serious environmental contamination of mine areas. This study investigated how arsenic behavior is controlled by a variety of processes, such as oxidation of sulfides and formation or alteration of secondary minerals, based on mineralogical methods. The study was carried out using the tailing samples obtained from Nakdong mine located in Jeongseongun, Gangwondo. After separating magnetic and non-magnetic minerals using pretreated tailing samples, each mineral sample was classified according to their colors and metallic lusters observed by the stereoscopic microscope. Subsequently, the mineralogical properties were determined using various instrumental analyses, such as x-ray diffractometer (XRD), energy dispersive spectroscopy (EDS), and electron probe micro analyzer (EPMA). The literature review confirmed that various ore minerals were identified in the Nakdong ore deposits. In this study, however, there were observed a few original ore minerals as well as secondary and/or tertiary minerals newly formed as a result of weathering including oxidation. In particular, we did not recognize pyrrhotite which has been known to originally exist in a large abundance, but peculiarly colloform-type iron (oxy)hydroxides were identified, which indicates most of pyrrhotite has been altered by rapid weathering due to its large reactivity. In addition, a secondary scorodites filling the fissure of weathered primary arsenopyrites were identified, and it is speculated that arsenic is immobilized through such a alteration reaction. Also, we observed tertiary iron (oxy)hydroxides were formed as a result of re-alteration of secondary jarosites, and it suggests that the environment of tailing has been changed to high pH from low pH condition which was initiated and developed by oxidation reactions of diverse primary ore minerals. The environmental change is mainly attributed to interactions between secondary minerals and parental rocks around the mine. As a result, not only was the stability of secondary minerals declined, but tertiary minerals were newly formed. As such a process goes through, arsenic which was immobilized is likely to re-dissolve and disperse into surrounding environments.

Copper Mineralization in the Haman-Gunbuk Area, Gyeongsangnamdo-Province: Fluid Inclusion and Stable Isotope Study (경상남도 함안-군북지역의 동광화작용: 유체포유물 및 안정동위원소 연구)

  • 허철호;윤성택;최상훈;최선규;소칠섭
    • Economic and Environmental Geology
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    • v.36 no.2
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    • pp.75-87
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    • 2003
  • The Haman-Gunbuk mineralized area is located within the Cretaceous Gyeongsang Basin along the southeastern part of the Korean peninsula. Major ore minerals, magnetite, scheelite, molybdenite and chalcopyrite, together with base-metal sulfides and minor sulfosalts, occur in fissure-filling tourmaline, quartz and carbonates veins contained within Cretaceous sedimentary and volcanic rocks anu/or granodiorite (118{\pm}$3.0 Ma). The ore and gangue mineral paragenesis can be divided into three distinct stages: Stage 1, tourmaline+quartz+Fe-Cu ore mineralization; Stage II, quartz+sulfides+sulfosalts+carbonates; Stage 111, barren calcite. Earliest fluids are recorded in stage I and early por-tions of stage II veins as hypersaline (35~70 equiv. wt.% NaCl+KCl) and vapor-rich inclusions which homogenize from ~30$0^{\circ}C$ to $\geq$50$0^{\circ}C$. The high-salinity fluids are complex chloride brines with significant concentrations of sodium, potassium, iron, copper, and sulfur, though sulfide minerals are not associated with the early mineral assemblage produced by this fluid. Later solutions circulated through newly formed fractures and reopened veins, and are recorded as lower-salinity(less than ~20 equiv. wt.% NaCl) fluid inclusions which homogenize primarily from ~200 to 40$0^{\circ}C$. The oxygen and hydrogen isotopic compositions of fluid in the Haman-Gunbuk hydrothermal system represents a progressive shift from magmatic-hydrothermal dominance during early mineralization stage toward meteoric-hydrothermal dominance during late mineralization stage. The earliest hydrothermal fiuids to circu-late within the granodiorite stock localiring the ore body at Haman-Gunbuk could have exsolved from the crystal-lizing magma and unmixed into hypersaline liquid and $H_2O$-NaCl vapor. As these magmatic fluids moved throughfractures, tourmaline and early Fe, W, Mo, Cu ore mineralization occurred without concomitant deposition of othersulfides and sulfosalts. Later solutions of dominantly meteoric origin progressively formed hypogene copper and base-metal sulfides, and sulfosalt mineralization.

Degradation Mechanisms of TCE in Cement/Fe(II) Systems (시멘트/Fe(II) 시스템에서의 TCE 분해 기작)

  • Lee, Yun-Mo;Kang, Wan-Hyup;Choi, Won-Ho;Hwang, In-Sung;Park, Joo-Yang
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.7
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    • pp.778-782
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    • 2007
  • This study investigated the dechlorination mechanisms of TCE by Fe(II) associated with cement. Batch slurry experiments were peformed to investigate the behaviors of selected ions; Fe(II), Fe(III), $Ca^{2+}$, $SO_4^{2-}$ in cement/Fe(II) system. The kinetic experiments of TCE in cement/Fe(II) systems showed that injected Fe(II) was mostly sorbed on cement within 0.5 day and 90% of injected 200 mM sulfate was sorbed on cement within 0.5 day when $[TCE]_0$ = 0.25 mM and $[Fe(II)]_0$ = 200 mM. The kinetic experiments of TCE in hematite/CaO/Fe((II) systems were conducted for simulation of cement/Fe(II) system. Calcium oxide that is one of the major components in cement hydration reactions or has a reactivity in limited conditions. Hematite assumed the ferric iron oxide component of cement. The reactivities observed in hematite/CaO/Fe(II) system were comparable to those reported for cement/Fe(II) systems containing similar molar amounts of Fe(II). The behavior of Fe(II) and $SO_4^{2-}$ sorbed on solid phase at an early stage of reaction in hematite/CaO/Fe(II) system was similar to that of cement/Fe(II) system. Ferric ion was released from hematite at an early period of reaction at low pH. The experimental evidence of kinetic test using hematite/CaO/Fe(II) system implies that the reactive reductant is a mixed-valent Fe(II)-Fe(III) mineral, which may be similar to green rust. Fe(II) sorbed on cement can be converted to new mineral phase having a reactivity such as Fe(II)-Fe(III) (hydr)oxides in cement/Fe(II) systems.

Physicochemical Properties of the Mung Bean (Phaseolus aureus L.) as Biohealth Functional Substance (기능성 소재로서 녹두(Phaseolus aureus L.)의 이화학적 특성)

  • Lee, Young-Geun;Bark, Si-Woo;Kim, Han-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.4
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    • pp.1096-1107
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    • 2019
  • This study on the physicochemical property of physiological activity substance in mung bean (Phaseolus aureus L.) was performed for the use as an functional food materialization. The proximate composition in the vacuum freeze dried mung bean was carbohydrate 57.20±0.29%, crude protein 26.40±0.69%, moisture 9.90±0.16%, crude ash 3.54±0.43%, and crude fat 2.96±0.26%, respectively. The vitamin content of mung bean was vitamin B5 0.62±0.013 mg/100 g, vitamin E 0.17±0.001 mg/100 g, vitamin B1 0.13±0.016 mg/100 g, and β-carotene 87.37±0.754 ㎍ RE/100 g, respectively. The mineral content of mung bean was potassium (K) 12,428.55±147.55 mg kg-1, magnesium (Mg) 2,053.32±14.13 mg kg-1, calcium (Ca) 1,966.40±14.53 mg kg-1, sodium (Na) 1,063.99±7.75 mg kg-1, iron (Fe) 63.77±0.98 mg kg-1, and manganese (Mn) 14.67±0.22 mg kg-1. The compositions of fatty acid were saturated fatty acid 29.23±0.03%, monoenes 20.30±0.04%, and polyenes 50.46±0.06%. Protein bound amino acid content of mung bean was 21.75±0.24 g%. And major amino acids were glutamic acid 3.93±0.03 g%, aspartic acid 2.68±0.03 g%, respectively. The composition of free amino acid of mung bean was 336.77±8.66 mg%, and major free amino acids were arginine, glutamic acid, asparagine, and aspartic acid. As a results of these experiment, Mung bean could be used a natural resouce and functional biohealth food substance.

Au-Ag-Te Mineralization by Boiling and Dilution of Meteoric Ground-water in the Tongyeong Epithermal sold System, Korea: Implications from Reaction Path Modeling (광화유체의 비등과 희석에 의한 통영 천열수계 Au-Ag-Te 장화작용에 대한 반응경로 모델링)

  • Maeng-Eon Park;Kyu-Youl Sung
    • Economic and Environmental Geology
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    • v.34 no.6
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    • pp.507-522
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    • 2001
  • At the Tongyeong mine, quartz, rhodochrosite (kutnahorite), muscovite, illite, pyrite, galena, chalcopyrite. sphalerite, acanthite, and hessite are the principal vein minerals. They were deposited under epithermal conditions in two stages. Ore mineral assemblages and associated gangue phases in stage can be clearly divided into two general associations: an early cycle (band) that appeared with introduction of most of the sulfides and electrum, and a later cycle in which base metal and carbonate-bearing assemblages (mostly rhodochrosite) became dominant. Tellurides and some electrum occur as small rounded grains within subhedral-to euhedral pyrite or anhedral galena in stageII. Sulfide mineralization is zoned from pyrite to galena and sphalerite. We have used computer modeling to simulate formation of four stages of vein genesis. The reaction of a single fluid with andesite host rock at 28$0^{\circ}C$, isobaric cooling of a single fluid from 26$0^{\circ}C$ to 12$0^{\circ}C$, and boiling and mixing of a fluid with both decreasing pressure and temperature were studied using the CHILLER program. Calculations show that the precipitation of alteration minerals is due to fluid-andesite interaction as temperature drops. Speciation calculations confirm that the hydrothermal fluids with moderately high salinities and pH 5.7 (acid), were capable of transporting significant quantities of base metals. The abundance of gold in fluid depends critically on the ratio of total base metals and iron to sulfide in the aqueous phase because gold is transported as an Au(HS)$_2$- complex, which is sensitive to sulfide activity. Modeling results for Tongyeong mineralization show strong influence of shallow hydrogenic processes such as boiling and fluid mixing. The variable handing in stageII mineralization is best explained by maltiple boilings of hydrothermal fluid followed by lateral mixing of the fluid with overlying diluted, steam-heated ground water. The degree of similarity of calculated mineral assemblages and observed electrum composition and field relationships shows the utility of the numerical simulation method in identifying chemical processes that accompany boiling and mixing in Te-bearing Au-Ag system. This has been applied in models to narrow the search area for epithermal ores.

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