• Journal of the Mineralogical Society of Korea
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• v.18 no.4 s.46
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• pp.259-266
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• 2005

X-ray diffraction (XRD), Electron microprobe analyses (EPMA) and heating experiments were used for mineralogical characterization of natural buserites collected from the Janggun and Dongnam mines. They are closely associated with $7-{\AA}$ phase (usually rancieite) in manganese oxide ores of the supergene oxidation zones of manganese carbonate deposits. Electron microprobe analyses give the average formula $(Ca_{0.78}Mg_{0.64}Mn^{2+}\;_{0.45})Mn^{4+}\;_{8.03}O_{18}\cdot13.2H_{2}O\;and\;(Zn_{0.81}Ca_{0.77}Mg_{0.26})Mn^{4+}\;_{8.00}O_{18}\cdot10.9H_{2}O$ for buserite from the Janggun and the Dongnam mine, respectively. The basal reflection of buserite from the Janggun mine shifts continuously from $9.86\;{\AA}\;at\;40^{\circ}C\;to\;7.60\;{\AA}\;at\;90^{\circ}C$, but the buserite from the Dongnam mine shows tendency of decreasing intensity in the $9.67^{\circ}C$ peak and of increasing intensity in the $7.53\;{\AA}$ peak in the range of $40\∼90^{\circ}C$, showing no gradual shifting of peaks.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.05a
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• pp.56-57
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• 2002

• Photonics industry news
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• s.68
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• pp.12-17
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• 2012

글로벌 마케팅 '총력전' 광주 광관련 기업들이 해외시장 개척에 안간힘을 쏟고 있다. LED 불황이 장기화되고 있는데다 기존 조명에 비해 현격히 높은 가격 부담이 발목을 잡아 국내 시장에서는 수요가 거의 발생하지 않기 때문이다. 당초 예상보다 LD시장의 개화가 더뎌지고 있고 유럽 금융위기 등 각종 악재로 전세계적인 경기불황이 나타남에 따라 공급계약이 취소되는 등 시장도 위축도고 있다. 이에따라 기업들은 유럽시장과 일본, 미국, 동남아 등 해외시장 개척에 사활을 걸고 있다. 광주시와 한국광산산업진흥회는 중소기업 판로개척을 위해 '광산업글로벌마케팅지원사업'을 추진중이다. 온실가스 절감이 화두로 제기된 유럽시장과 FTTH 바람이 불고 있는 미국과 중국 등이 주요타깃이다. 광주지역 360곳의 기업들이 수요조사와 LED, 광통신, 광융합제품 기술시장동향을 꼼꼼히 파악해 매년 20명 규모의 무역 사절단을 파견하고 있다. 실제 초이스라이텍, 고려오트론, 포토닉스트레이드그룹, 인탑스LED는 지난달 21일부터 30일까지 스페인, 체코, 독일을 잇따라 방문해 신흥시장 개척에 나섰다.

• Journal of the Mineralogical Society of Korea
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• v.2 no.2
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• pp.90-99
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• 1989

Manganese deposits ar the Dongnam mine occur as vein in the Pungchon limestone of Ordovician age. Manganese ore veins consist of the hydrothermal manganese carbonate ores in the deeper part and the supergene manganese oxide ores in the shallow part. Manganese carbonate ores consist mainly of rhodochrosite, with minor amount of proxmangite, garnet, calcite, quartz, pyrite, galena and sphalerite. Manganese oxide ores consist of rancieite, buserite, birnessite, vernadite, todorokite, pydrolusite, nsutite, hydrohetaerosite and goethite. Manganese oxide minerals were formed in the following sequences; 1) rhodochrosite ${\rightarrow}$ vernadite ${\rightarrow}$ birnessite ${\rightarrow}$ nsutite ${\rightarrow}$ pyrolusite, 2) pyroxmangite ${\rightarrow}$ birnessite, 3) Buserite ${\rightarrow}$ ransieite. Todorokite, buserite and hydrohetaerolite were precipitated from solution in the later stage. The natural analogue of synthetic buserite has been discovered from the mine. It has been disclosed that buserite transforms to rancicite by dehydration, and that distinction between buserite and todorokite is possible by X-ray diffraction studies combined with dehydration experiment. Minerals identified from the mine have been characterized using various methods including polarizing microscopy, X-ray diffraction, thermal analysis, infrared spectroscopy, X-ray diffraction, thermal analysis, infrared spectroscopy, elecrton microscopy and dehydration experiment.

• Photonics industry news
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• s.19
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• pp.8-13
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• 2003

최근 중국경제는 사스충격, 세계경기의 침체등의 악재에도 불구하고 전년동기대비 8%이상의 고성장을 지속하고 있음을 알 수 있었다. 또한 중국 경제의 대외지표인 수출액은 2003년 상반기 기준 1,900억 달러로 전년동기대비 34%증가, 5월까지의 외자유치도 230억달러로 전년 동기대비 48% 증가를 보이는 등 지속적으로 호조를 보이고 있으며, 또한 미국 및 일본의 경기회복 지연, 한국과 동남아시아의 경기 침체 속에서 중국만이 홀로 호황을 지속하고 있으며 중국 천안문 사건 이래 가장 큰 위기로 평가되는 사스 확산의 상황에서도 상반기에 고성장을 실현하는 중국 경제의 저력을 다시 한번 느낄 수 있었다. 본고에서는 이러한 중국 경제, 특히 IT부문의 발전 속에서 우리나라 광산업체의 활로를 모색하고 중국 진출의 방안을 다시 한번 되짚어 보고자 한다.

• Journal of the Mineralogical Society of Korea
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• v.16 no.4
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• pp.333-339
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• 2003

A new mineral, Zn analogue of rancieite (Chimooite), has been discovered at the Dongnam mine, Korea. It occurs as compact subparallel fine­grained flaky or acicular aggregates in the massive manganese oxide ores which were formed by supergene oxidation of rhodochrosite­sulfide ores in the hydrothermal veins trending NS­N25E and cutting the Pungchon limestone of the Cambrian age. The flakes of chimooite are 0.2 mm for the largest one, but usually less than 0.05 mm. The acicular crystals are elongated parallel to and flattened on (001). This mineral shows gradation to rancieite constituting its marginal part, thus both minerals are found in one and the same flake. Color is bluish black, with dull luster and brown streak in globular or massive aggregates. Cleavage is perfect in one direction. The hardness ranges from 2.5 to 4. Under reflected light it is anisotropic and bireflectant. It shows reddish brown internal reflection. Chemical analyses of different parts of both minerals suggest that rancieite and chimooite constitute a continuous solid solution series by cationic substitution. The empirical chemical formula for chimooite has been calculated following the general formula, $R_2_{x}$ M $n^{4+}$$_{9­x}$ $O_{18}$ $.$n$H_2O$ for the 7 $\AA$ phyllomanganate minerals, where x varies from 0.81 to 1.28 in so far studied samples, thus averaging to 1.0. Therefore, the formula of Zn­rancieite is close to the well­known strochiometric formula $_Mn_4^{4+}$ $O_{9}$ $.$4$H_2O$. The mineral has the formula (Z $n_{0.78}$N $a_{0.15}$C $a_{0.08}$M $g_{0.01}$ $K_{0.01}$)(M $n^{4+}$$_{3.98}$F $e^{3+}$$_{0.02}$)$_{4.00}$ $O_{9}$ $.$3.85$H_2O$, thus the ideal formula is (Zn,Ca)M $n^{4+}$$_4$ $O_{9}$ $.$3.85$H_2O$. The mineral has a hexagonal unit ceil with a=2.840 $\AA$ c=7.486 $\AA$ and a : c = 1 : 2.636. The DTA curve shows endothermic peaks at 65, 180, 690 and 102$0^{\circ}C$. The IR absorption spectrum shows absorption bands at 445, 500, 1630 and 3400 c $m^{1}$. The mineral name Chimooite has been named in honour of late Prof, Chi Moo Son of Seoul National University.ity.versity.ity.y.

• Journal of the Mineralogical Society of Korea
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• v.5 no.2
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• pp.93-101
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• 1992

Several "Napseok" mines are distribute in the Miryang area where the volcanic rocks are hydrothermally altered. The "Napseok" are pyrophyllite and dickite, with a small amount of silicates such as quartz, illite, tosudite and dumortierite. Other associated minerals are oxides, hydroxides, sulfides, sulfates and phosphates. Pyrophyllite which occurs as 2M polytype exhibits that the basal spacing increases due to dehydroxylation at 750${\circ}C$. Halloysite shows tubular forms. Wavellite is precipitated in fissures during the latest stage of the hydrothermal alteration process. Five mineral zones, that is pyrophyllite-deckite, illite, halloysite, silica, and albite-chlorite zones, are recognized with decreasing alteration degree. Clay minerals were formed by leaching of Si and alkali ions fron the country rocks, considering mineral assemblages, pyrophyllite polytype and thermodynamical data reported in the literature, temperatures of formation of main clay deposits are assumed to be 270 to 350${\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.33-41
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• 2001

Enormous volumes of mining wastes from the abandoned and closed mines are disposed without a proper treatment in the upper Okdong River basin at Southeastern part of Kangwon Province. Erosion of these wastes contaminates soil, surface water, and sediments with heavy metals. Objectives of this research were to fractionate heavy metals in the mine tailing stored in the Sangdong Tungsten tailing dams and to assess the potential pollution index of each metal fraction. Tailing samples were collected from tailing dams at different depth and analyzed for physical and chemical properties. pH of tailings ranged from 7.3 to 7.9. Contents of total N and organic matter were in the ranges of 3.2~5.5%, and 1.3~9.1%, respectively. Heavy metals in the tailings were higher in the newly constructed tailing dam than those in the old dam. Total concentrations of metals in the tailings were in the orders of Zn > Cu > Pb > Ni > Cd, exceeded the corrective action level of the Soil Environment Conservation Law and higher than the natural abundance levels reported from uncontaminated soils. Relative distribution of heavy metal fractions was residual > organic > reducible > carbonate > adsorbed, reversing the degree of metal bioavailability. Mobile fractions of metals were relatively small compared to the total concentrations. Distribution of metals in the tailing dam profiles was metal specific. Concentrations of Cu at the surface of tailing dams were higher than those at the bottom. Pollution index (PI) values of each fraction of metals were ranged from 4.27 to 8.51 based on total concentrations. PI values of mobile fractions were lower than those of immobile fractions. Results on metal fractions and PI values of the tailing samples indicate that tailing samples were contaminated with heavy metals and had potential to cause a detrimental effects on soil and water environment in the lower part of the stream. A prompt countermeasure to prevent surface of tailings in the dams from water and wind erosions is urgently needed.