• Economic and Environmental Geology
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• v.41 no.6
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• pp.773-795
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• 2008

The major import minerals of South Korea are copper ore, lead-zinc ore, iron ore, manganese ore and molybdenum ore. Oversea resources development of South Korea have 92 projects in 14 nations of Asia, 29 projects in 10 nations of America and Europe, and 14 projects in 9 nations of Middle Asia and Africa. But, most projects of them are found in Australia, China, Mongolia and Indonesia. The most projects of the Australia, China and Indonesia are interested in coal and a little projects of them have manganese, iron, lead-zinc, nickel, copper, gold, molybdenum, rare earth elements and uranium. The most projects of the Mongolia are interested in gold and rare earth elements. Representative ore deposits models of metal resources are Orogenic lode deposits, Volcanogenic massive sulphide deposits, Porphyry deposits, Sedimentary exhalative deposits, Mississippi valley type deposits, Iron oxide copper-gold deposits and Magmatic nickel-copper-platinum group element deposits based on global distribution, reverses and grades of their deposits models. If oversea mineral resources will be examined the mineral reserves, mineral mine production and ore deposits models of nations and then survey and investigate of mineral resources, we may be maintained ore body of high grade at survey area and decrease the investment risk.

• Economic and Environmental Geology
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• v.41 no.3
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• pp.287-297
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• 2008

In order to estimate the preliminary development feasibility according to the commodity, the content of 8 strategic metallic commoditites(Pb, Zn, Cu, Fe, Mo, W, Au, U) in 68 ore specimens obtained from 34 metallic mines within the Taebaegsan-Hwanggangri mineralized zone were analyzed. Analytical results are as follows. The ore specimen of Sangdong mine contained 23% copper(cut-off grade=0.7%) and those of Cheongil and Samhwanghak mines contained average 5% zinc(cut-off grade=2.0%). Especially, the detailed investigation on the above-mentioned mines is required. And, in case of molybdenum(cut-off grade=0.02%) content in Yeonhwa No. 2(0.04%) and Hong-cheon mine(0.02%), and lead(cut-off grade=0.58%) content in Wongasa mine(0.70%), and gold(cut-off grade=10ppm) content in Dongmyoung(279ppm) and Samhwanghak mine(251ppm), it is required to elastically carry out the revaluation on reopening of mines in terms of the international metal price. On the other hand, in case of uranium, iron and tungsten, it is thought that there are no mines with the development potential value in this study.

• Economic and Environmental Geology
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• v.35 no.4
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• pp.355-368
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• 2002

The multi-storied Daewonsa stone pagoda (Treasure No. 1112) in the Sancheong, Korea was studied on the basis of deterioration and geological safety diagnosis. The stone pagoda is composed mainly of granitic gneiss, partly fine-grained granitic gneiss, leucocratic gneiss, biotite granite and ceramics. Each rock of the pagoda is highly exfoliated and fractured along the edges. Some fractures in the main body and roof stones are treated by cement mortar. This pagoda is strongly covered with yellowish to reddish brown tarnish due to the amorphous precipitates of iron hydroxides. Dark grey crust by manganese hydroxides occur Partly, and some Part coated with white grey gypsum and calcite aggregates from the reaction of cement mortar and rain. As the main body, roof and upper part of the pagoda, the rocks are developed into the radial and linear cracks. Surface of this pagoda shows partly yellowish brown, blue and green patchs because of contamination by algae, lichen, moss and bracken. Besides, wall-rocks of the Daewonsa temple and rock aggregates in the Daewonsa valley are changed reddish brown color with the same as those of the pagoda color. It suggests that the rocks around the Daewonsa temple are highly in iron and manganese concentrations compared with the normal granitic gneiss which color change is natural phenomena owing to the oxidation reaction by rain or surface water with rocks. Therefore, for the attenuation of secondary contamination, whitening and reddishness, the possible conservation treatments are needed. Consisting rocks of the pagoda would be epoxy to reinforce the fracture systems for the structural stability on the basements.

• The Journal of the Petrological Society of Korea
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• v.23 no.4
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• pp.375-383
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• 2014

Precambrian granitic gneisses and Cambrian meta-sedimentary rocks are prevalently distributed in the eastern part of the Taebaegsan region, and biotite granitic batholith of the Jurassic period (?) is found in the southern part of Uljin-si. But small scale leucocratic granitic stocks which commonly found here and there have been rather neglected in the previous studies. The presence of leucocratic granites could be differentiated from the older granitic rocks and biotite granite through the outcrop characteristics, mineral species and geochemical compositions. For the effective comparison between the older granitic rocks and leucocratic ones, pale gray to gray coloured Hongjesa granitic gneiss with granular texture was selectively chosen. The Hongjesa granitic gneiss and biotite granite usually have rather plenty of coloured minerals such as biotite and chlorites. But the leucocratic granites often show sericitic alteration due to the albitization and greisenisation during the post-magmatic alteration, and shows rather bright appearance because of poor amount of coloured minerals. Since all of granitic rocks passed rather high degrees of magmatic differentiation, they belong to calc-alkalic and peraluminous in their characters. Among the alkali elements of the leucocratic rocks $K_2O$ shows higher increase than those of the other granitic rocks, and $Na_2O$ only represents slight decrease than those of the Hongjesa granitic gneiss and Uljin granite. On the other hand, CaO and total Fe content are clearly decreased than those of the Hongjesa granitic gneiss and Uljin granite.

• Food Science and Preservation
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• v.8 no.1
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• pp.47-53
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• 2001

In order to investigate the effect of two type of ceramic film(15% SiO$_2$ incorporated LDPE, 10% zeolite incorporated LDPE), perforated film and LDPE film on freshness of shiitake mushroom, weight loss, surface color and marketability of mushroom were measured during MA storage at 5 $\^{C}$ and 20$\^{C}$. The effect of packaging films on weight loss and marketability index of shiitake mushroom at 20$\^{C}$ was negligible due to its rapid physiological changes. However, the effect of packaging films on surface color of shiitake mushroom was significant at 20$\^{C}$ storage, but not at 5$\^{C}$ storage. During MA storage of shiitake mushroon, discoloration were reduced effectively by ceramic films and weight loss were by LDPE film, but they had little difference between packaging 51ms. However, there were significant differences among the packaging films in marketability of mushroom induced by water vapor inside package and accelerate its spoilage and browning. Ceramic film(15% SiO$_2$ incorporated LDPE) showed best result to maintain marketability of shiitake mushroom and zeolite incorporated film, perforated film, LDPE film in order.

• Economic and Environmental Geology
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• v.34 no.2
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• pp.157-166
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• 2001

Numerous base-metal bearing hydrothermal quartz vein deposits occur in the Hunan province of southern China. The Tangguanpu lead-zinc-tin-silver mine is the major producer among these deposits. Lead-zinc-tin-silver mineralization occurs in a single stage of massive quartz veins which filled fractures in fault zones within Paleozoic metasedimentary rocks. Sphalerite, chalcopyrite, galena, pyrite, arsenopyrite and pyrrhotite are the principal sulphide minerals in the Tangguanpu lead-zinc ores with minor amounts of tin- and antimony-bearing sulphides (stannite, teallite, boulangerite and tetrahedrite). Based on the iron and zinc partitioning between coexisting stannite and sphalerite, the formation temperature for this mineral assemblage range from 300$^{\circ}$ to 330$^{\circ}$C, which relatively agree with the upper part of homogenization temperature of fluid inclusion in quartz (20T-358$^{\circ}$C). Fluid inclusion data show that main lead-zine-tin-silver mineralization occurred from $H_{2}O$-NaCl fluids with relatively low salinities (11.2-7.3 wl.% eg. NaCI) at temperatures between 207$^{\circ}$ and 358$^{\circ}$C. The relationship between homogenization temperature and salinity suggests a history of cooling and dilution followed by initial boiling. Evidence of initial fluid boiling may indicate the fluid trapping pressures of 180 bars. The ${\delta}^{34}S{{\Sigma}S}$ values of -5.0 to 1.1 %, indicate an igneous source of sulfur in the Tangguanpu lead-zinc-tin-silver hydrothermal fluids.

• Conservation Science in Museum
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• v.25
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• pp.63-84
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• 2021

In order to investigate the diverse physicochemical changes that occurred in traditional Korean pottery during its production, including before and after firing, this study produced six replicas of a celadon maebyeong inlaid with cloud-and-crane designs, respectively corresponding to the process of shaping, carving, inlaying designs, first firing, glazing and second firing, respectively. It then conducted a scientific study of these six replicas and analyzed their images through high-resolution three-dimensional transmission imaging. The materials used for the replicas show different mineral phases and even colors depending on the components of each material. For example, black inlay with a high content of iron oxide (Fe₂O₃) shows dark colors and white inlay with a high alumina (Al₂O₃) content appears white. Physicochemical properties such as chromaticity and magnetic susceptibility and major components of the replicas were confirmed by the differences in the density in the computed tomography (CT) images. The characteristics of fired products such as fine structure, absorption ratio, apparent porosity, and other characteristics of the major mineral components were identified by the presence of pores and the formation of cracks inside the replicas in the image analysis.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.391-405
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• 2020

Leaching chracteristics of Andong-dam sediment was conducted for heavy metal and nutrients. Five mixed sediment samples were prepared and leaching was conducted under aerobic and anaerobic condition for 60 days. Cd, Cu, Pb, Cr, Zn, Hg, As, Fe, Mn, phosphorus, and nitrogen were analyzed at each sampling time. The leaching rate of phosphorus was higher in anaerobic condition comparing with that of under aerobic condition. Some samples showed higher than the water-quality level IV. In case of As and Cd which showed highest contamination level in the sediment, leached concentration were 0.028 mg/L and 0.003 mg/L in maximum, respectively. The leached concentration is below than the lake water quality standard of Korea. Other heavy metals including Cu, Pb, and Cr also showed similar trend. Five step sequential extraction showed that easily extractable 1-2 step portion such as ion-exchangeable and adsorbed one was less than 10% and the most of the portion was residual. For As and Cd, the residual portion were 80% and 95% respectively indicating the risk by the heavy metal leaching into the lake for a short period was not high in comparing with the contamination levels.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.61-68
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• 2023

This study analyzed and compared the physicochemical characteristics of topsoil and subsoil of Grade 1 soil from an igneous rock area on the ecological and nature map. The water content and pH of the collected soil samples were measured, and X-ray fluorescence and X-ray diffraction analyses were performed. The results showed that the water content of the topsoil was higher than that of the subsoil, and its pH was more acidic than that of the subsoil. According to the X-ray fluorescence analysis results, sample I9 was closest to kaolinite, while sample I7 was most distant from kaolinite. All other samples were located between samples I7 and I9. The X-ray diffraction analysis showed that the average content of clay minerals was higher in the topsoil than in the subsoil. The most notable clay minerals produced included illite, vermiculite, kaolinite, chlorite, and gibbsite. The results of this study will be used as a basic data for topsoil restoration to convert subsoil into topsoil.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.263-270
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• 2024

In this study, impact factors for dehydration with KOMIR-Tube system using flocculant and dewatering tube were evaluated for mine drainage sludges. The experiments were conducted on semi-active facility sludges with water contents above 90 % using KOMIR-Tube system. The flocculant and input amount were determined from laboratory experiment and the dewatering efficiency was verified onsite experiment. The sludge characteristics were identified by instrumental analysis such as zeta potential measurement, particle size analysis, XRD, XRF and SEM-EDS. Selection of flocculants for sludge dewatering treatment need to consider not only precipitated rate but also filterated rate. Floc size has to keep at least 0.7 mm. From on-site experiments, sludge dewatering using KOMIR-Tube system suggests to carry out April and May that is low rainfall and humidity considering to climate conditions. Also, dewatering rate depends on the crystal degree of mineral that mainly makes up sludges. Particularly, goethite of the iron hydroxides has better dewatering rate than ferrihydrite. Ferrihydrite is low degree of crystallinity and uncleared or broad shaped crystal, goethite is good crystallinity with needle shaped crystal so that the effect of flocculation and dewatering showed to depend on the crystal. In results, impact factors of dewatering for mine drainage sludges are related to flocculant, climate, crystallinity and shape of iron hydroxides.