• Journal of Conservation Science
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• 제28권2호
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• pp.175-184
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• 2012

A purpose of this research is to find out characteristic of bronze artifacts and gold ornaments excavated from Xiongnu tombs No. 2~4 at Duurlig Nars in Mongolia through scientific analysis of them. The Tombs are comparatively small. There were still lots of relics remaining although the tombs had been already robbed. Also the tombs are evaluated important since the origin of them show coexisting of chinese and northern style. First of all, an analysis result about bronze vessels found in this site, they have high lead(Pb) content and relatively low tin(Sn) content, as compared with the Bronze Han Mirror and End-fittings of Bronze Parasol Rib. Especially in case of bronze tray and bronze lamp from the no. 2 tomb and also bronze cauldron from the no. 4 tomb contain only 1wt% of tin which means binary alloy composition(Cu-Pb). Also, in the case of gold ornaments found in the no. 2 tomb, they have comparatively high purity. And the research suppose that the high possibility of that they were used soldering using alloy of Au-Cu or diffused bonding(using malachite and copper oxide) for joining gold grains of gold granulation ornament. Further scientific research and analysis in Mongolia and other countries will provide more clues to solve mystery of Xiongnu culture.

• Resources Recycling
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• 제21권2호
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• pp.3-8
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• 2012

In the points of the environmental conservation and the recirculating utilization of limited resources, it is very important to recover valuable metals like Au, Ag, Pd, Cu, Sn, Ni, Co, and Li used as industrial raw materials from urban ores. From now, many processes have been developed for recovering the valuable metals contained in urban ores and some of them have been operated commercially. In the paper, pyrometallurgical processes developed for reclaiming valuable metals from urban ores will be briefly introduced.

• Economic and Environmental Geology
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• 제39권1호
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• pp.9-25
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• 2006

Baekun gold-silver deposit is an epithermal quartz vein that is filling the fault zone within Triassic or Jurassic foliated granodiorite. Mineralization is associated with fault-breccia zones and can be divided into two stages. Stage I which can be subdivided early and late depositional stages is main ore mineralization and stage II is barren. Early stage I is associated with wallrock alteration and the formation of sulfides such as arsenopyrite, pyrite, pyrrhotite, sphalerite, marcasite, chalcopyrite, stannite, galena. Late stage I is characterized by Au-Ag mineralization such as electrum, Ag-bearing tetrahedrite, stephanite, boulangerite, pyrargrite, argentite, schirmerite, native silver, Ag-Te-Sn-S system, Ag-Cu-S system, pyrite, chalcopyrite and galena. Fluid inclusion data indicate that homogenization temperatures and salinity of stage I range from $171.6^{\circ}C\;to\;360.8^{\circ}C\;and\;from\;0.5\;to\;10.2\;wt.\%\;eq.$ NaCl, respectively. It suggest that ore forming fluids were cooled and diluted with the mixing of meteoric water. Also, Temperature (early stage I: $236\~>380^{\circ}C,\;$ late stage $I: <197\~272^{\circ}C$) and sulfur fugacity (early stage $I:\;10^{-7.8}$ a atm., late stage I: $10^{-14.2}\~10^{-l6}atm$.) deduced mineral assemblages from stage 1 decrease with paragenetic sequence. Sulfur ($2.4\~6.1\%_{\circ}$(early stage $I=3.4\~5.3\%_{\circ},\;late\;stage\;I=2.4\~6.1\%_{\circ}$)), oxygen ($4.5\~8.8\%_{\circ}$(quartz: early stage $I=6.3\~8.8\%_{\circ}$, late stage $I=4.5\~5.6\%_{\circ}$)), hydrogen ($-96\~-70\%_{\circ}$ (quartz: early stage $I=-96\~-70\%_{\circ},\;late\;stage\;f=-78\~-74\%_{\circ},\;calcite:\;late\;stage\;I=-87\~-76\%_{\circ}$)) and carbon ($-6.8\~-4.6\%_{\circ}$ (calcite: late stage I)) isotope compositions indicated that hydrothermal fluids may be magmaticorigin with some degree of mixing of another meteoric water for paragenetic time.

• Economic and Environmental Geology
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• 제42권3호
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• pp.177-193
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• 2009

The Samgwang deposit consists of eight massive mesothermal quartz veins that filled NE and NW-striking fractures along fault zones in Precambrian granitic gneiss of the Gyeonggi massif. The mineralogy and paragenesis of the veins allow two separate discrete mineralization episodes(stage I=quartz and calcite stage, stage II-calcite stage) to be recognized, temporally separated by a major faulting event. The ore minerals are contained within quartz and calcite associated with fracturing and healing of veins that occurred during both mineralization episodes. The hydrothermal alteration of stage I is sericitization, chloritization, carbonitization, pyritization, silicification and argillization. Sericitic zone occurs near and at quartz vein and include mainly sericite, quartz, and minor illite, carbonates and chlorite. Chloritic zone occurs far from quartz vein and is composed of mainly chlorite, quartz and minor sericite, carbonates and epidote. Fe/(Fe+Mg) ratios of sericite and chlorite range 0.45 to 0.50(0.48$\pm$0.02) and 0.74 to 0.81(0.77$\pm$0.03), and belong to muscovite-petzite series and brunsvigite, respectiveIy. Calculated $Al_{IV}$-FE/(FE+Mg) diagrams of sericite and chlorite suggest that this can be a reliable indicator of alteration temperature in Au-Ag deposits. Calculated activities of chlorite end member are $a3(Fe_5Al_2Si_3O_{10}(OH)_6$=0.0275${\sim}$0.0413, $a2(Mg_5Al_2Si_3O_{10}(OH)_6$=1.18E-10${\sim}$7.79E-7, $a1(Mg_6Si_4O_{10}(OH)_6$=4.92E-10${\sim}$9.29E-7. It suggest that chlorite from the Samgwang deposit is iron-rich chlorite formed due to decreasing temperature from high temperature(T>450$^{\circ}C$). Calculated ${\alpha}Na^+$, ${\alpha}K^+$, ${\alpha}Ca^{2+}$, ${\alpha}Mg^{2+}$ and pH values during wallrock alteration are 0.0476($400^{\circ}C$), 0.0863($350^{\circ}C$), 0.0154($400^{\circ}C$), 0.0231($350^{\circ}C$), 2.42E-11($400^{\circ}C$), 7.07E-10($350^{\circ}C$), 1.59E-12($400^{\circ}C$), 1.77E-11($350^{\circ}C$), 5.4${\sim}$6.4($400^{\circ}C$), 5.3${\sim}$5.7($350^{\circ}C$)respectively. Gain elements(enrichment elements) during wallrock alteration are $TiO_2$, $Fe_2O_3(T)$,CaO, MnO, MgO, As, Ag, Cu, Zn, Ni, Co, W, V, Br, Cs, Rb, Sc, Bi, Nb, Sb, Se, Sn and Lu. Elements(Ag, As, Zn, Sc, Sb, Rb, S, $CO_2$) represents a potential tools for exploration in mesothermal and epithermal gold-silver deposits.

• Korea journal of population studies
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• 제13권2호
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• pp.1-18
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• 1990

This is a study which attempt to analyze changing patierns of economic active popu-lation, t o estimato- future patterns, and exa- mine vartons problems arises by changing c ire u mst ances of t he labor force market in- clunging soici al, economic ic, heathl th and demoi-graph ic aspects. We have constructed series of wotking life table which are useful in syt uiolyioig the lirocess of growth and structural change of labor force. Work i ng life tables represent ihie life eyele of econrmic' activity in hi ypothetical cohorts, that is. gen-erat i on of men Sn bject at eat' b period ot f their lives th given ra to's o mor tali it y and of par-- tici pation in economic activities. The tabloes prot' ide measorues of the alvet'age he ng t able of economically aeti \- e life. and agespecific rates of en trannee' into and retirement from the hahn' force. In const routing working life tables, age-specific activity rates and life tabole popula- titoto which represents contemporary condi-tions of moortality in Korea au'e the basic' maltoerials. We have derived the age-specific rates foorm economically active population survey, whoich were conducted by the Bureau of Statistics, Economic Planning Borard of the Korean government. Working life tables are constructed for men wtable these materi- als in the year of 1970, 1980 and 1988 by a modified Wolfbein-Wool's method. Some of the findings may be summerized as follow : 1) A central part of constructing working life table is calculation of stationary' economic active population, which represents the number of men in the stationtary population extoected to be in the labor force at each age group in the life span. The stationary economic active population by age have generally a universal pattern, where they rise sharply in the early twenties, approach its' peak in the thirties decline thereafter. at first graolually and then more rapidly at an advanced age. Korean men show the same general pa ttern of age distribution of stationary eco-- nomic active population with sharp increase hegining from the age interval of 20 to 24, reaching to maximum level at older age. The population. however, presumably, increased substantially due to increaseing school atte endance rates. Another difference exiSts in the youngest age groups, that is the activity rate in the year of 1988 is lower than that of Japan. The table shows an analysis of changes in the age distrihution of labor force between 1970, 1980 and 1988. 2) It was shown an analysis of changes in the age distribution and cause of separation from labor force. The entrance rate to labor force has increased from 18~\5 persons to 299 persons per 1000 head of stationary population between that of 1980 than that of 1988 for Korean men in 20~24 age group. The entrace rate to labor force shows a rapid entrance appearance concentrated on the 15~24 age group. The separation rate from labor force by retirment in Korea in the year of 1988 shows a great difference of the about four times as much as that of Japan. 3) The functions of table illustrate the patterns of working life of males in Korea in 1970, 1980 and 1988. The average remaining number of economically active years, e at age 15 in 1988 is 46.39 which is 2.12 years of increase compared with that of at age 15 in 1970,1980 and 1988 are 43.90,44.27 and 46.39 respectively, showing steadily increase dur- ing the past double decade the increase in the length of economically active life various age may be considered to have come both from extention of general life expectancy and from increasing entrance rate to economic activity in high age that of working is far greater in 1988 than that of 1980. The gaps between expectation of life and average remaining years of economically active widened due to rapid improvement of mortality level in Ko- rea. This observation together with the population pressure by the appearance of a group of younger population implies that constant increase of economically inactive population among older age group.