• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.1-13
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• 1994

The industrial minerals play an important role in mining sector. More than 70 % of total mineral production come from industrial mineral sector. This paper reviews geological occurrence of kaolin, pyrophyllite and limestone, and current demand-supply status of major industrial minerals in the Republic of Korea. The kaolin is mainly distributed in the Kyeongsang province, formed by deep weathering of Precambrian anorthosite on mountainside of gentle slope. The pyrophyllite mainly occurs in the Kyeongsang and Chulla provinces, formed by hydrothermal alteration of late Cretaceous andesitic and rhyolitic rocks. Pyrophyllite comprises massive and lenticular bodies and contains minor amounts of kaolin, alunite and pyrite, in some places andalusite and illite. The limestone(Great Limestone Series of Cambrian age) is distributed widely in the Kwangwon and Chungcheong provinces. The limestone bodies are approzimately 70 km long and 3 km wide, elongated NE-ward, and show high grade of CaO content. In 1992, the self-sufficiency ratio of 44 nonfuel (metallic and non-metallic) minerals was no more than 30 percent. However, the ratio of 27 industrial minerals (non-metallic) represents high value of about 72 percent. The export/productjon ratio of the industrial minerals shows decreasing patterns from 12.2 % in 1983 to 4.2 % in 1992. Also the import/production ratio shows rapidly decreasing pattern from 84 % in 1983 to 38.2 % in 1992.

• Journal of the Korean Ceramic Society
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• v.23 no.5
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• pp.17-24
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• 1986

β'-Sialon with different compositions was synthesized by the carbothermal reduction-nitridation of compacts containing kaolin graphite and silicon or aluminum at temperature of 1300-1450℃ under flowing gas of 90% N2-10% H2 or 20hrs. Quantitative analysis of minerals which were formed in the specimens was carried out by using the calibration curve which has been prepared from X-ray diffraction patterns. The obtained results were as follows : 1. In the formation of β'-Sialon by carbothermal reduction-nutridation of Si-Al-O-C system mixtures at 1400℃ for 20hrs. (2) β'-Sialon as a major mineral and α-Al2O3 as a minor mineral were identified in the specimen which was prepared of kaolin and graphite. (3)α-Al2O3 and 15R as a minor minerals were measured in the specimen which was prepared of kaolin aluminum and graphite. (4) AlN instead of α-Al2O3 and 15R was formed in the compacts that excess graphite(=35 wt%) was added to the mixture of kaolin and aluminium. 2. As the reaction time and temperature were increased the formation of β'-Sialon was increased whereas the phases of mllite SiC and Si2ON2 were decreased gradually.

• Journal of the Mineralogical Society of Korea
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• v.13 no.3
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• pp.147-163
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• 2000

The mineralogy and chemical composition of reddish to brownish yellow residual soils, so called "Hwangto" have been examined according to representative host rocks. The result of the study indicates that Hwangto consists of 40-80% clay minerals and various minerals such as quartz, feldspar, hornblende, goethite, and gibbsite. Clay minerals include kaolinite, halloysite, illite, hydroxy interlayered vermiculite (HIV), mica/vermiculite interstratifield mineral and chlorite. The mineralogical constituents and contents of Hwangto were different depending on the types of host rocks. Moreover, the Jurassic granitic rocks contain relatively more kaolin minerals, whereas the Cretaceous granitic rocks contain more HIV and illite. In addition, reddish Hwangto contains relatively more kaolinite and HIV, and yellowish Hwangto contains more illite and halloysite. It is suggested that feldspars and micas of host rocks were chemically weathered into illite, halloysite, illite/vermiculite interstratified minerals, and HIV, and finally into kaolinite. Compared with their host rocks, the major chemical compositions of Hwangto tend to contain more $Al_2O_3,\;Fe_2O_3,\;H_2O$ in amount and less Ca, Mg, and Na. Hwangto contains relatively high amount of trace elements, P, S, Zr, Sr, Ba, Rb, and Ce including considerable amount of Li, V, Cr, Zn, Co, Ni, Cu, Y, Nb, La, Nd, Pb, Th in excess of 10 ppm. Relatively high amount of most trace elements were detected in the Hwangto. The major and minor chemical compositions of the Hwangto were different depending on the types of host rocks. However, their difference was in the similar range compared with the compositions of host rocks.

• Economic and Environmental Geology
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• v.44 no.3
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• pp.203-215
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• 2011

Geochemical and mineralogical properties of a contamited soil should be taken into account to decide a remediation strategy for a given contaminant because development and optimization of soil remedial technologies are based on geochemical and mineralogical separation techniques. The objective of this study was to investigate the geochemical and mineralogical characteristics of arsenic-contaminated soils. The arsenic-contaminated soil samples were obtained from Chonam gold mine, Gwangyang, Chonnam, Particle size analysis, sequential extraction, and mineralogical analyses were used to characterize geochemical and mineralogical characteristics of the As-contaminated soils. Particle size analyses of the As-contaminated soils showed the soils contained 17-36% sand, 25-54% silt, 9-28% clay and the soil texture were sandy loam, loam, and silt loam. The soil pH ranged from 4.5 to 6.6. The amount of arsenic concentrations from the sequential soil leaching is mainly associated with iron oxides (1 to 75%) and residuals (12 to 91%). Major minerals of sand and silt fractions in the soils were feldspar, kaolinite, mica, and quartz and minor mineral of which is an iron oxide. Major minerals of clay fraction were composed of illite, kaolinite, quartz, and vermiculite. And minor minerals are iron oxide and rutile. The geochemical and mineralogical analyses indicated the arsenic is adsorbed or coprecipitated with iron oxides or phyllosilicate minerals. The results may provide understanding of geochemical and mineralogical characteristics for the site remediation of arsenic-contaminated soils.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.349-354
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• 2008

Semiquantitative mineralogical analysis of clays in soils was performed to understand the distribution of clay minerals in relation to bedrock lithology on the northern basin of the Nakdong River. The soils developed on the granitic bedrocks have high contents of kaolinite and smectite. mite was the major clay mineral in the soils from sedimentary bedrocks, with minor kaolinite, smectite, and intergrade (interstratified chlorite-smectite or hydroxy-interlayed vermiculite) clay minerals. Illite and kaolinite contents of the soils from metamorphic and volcanic bedrocks fall between those of the soils from the granitic bedrocks and those of the soils from the sedimentary bedrocks. The clay mineralogy of the soils depends on the compositions of bedrock minerals and their susceptibility to chemical weathering. The weathering of plagioclase resulted in the high kaolinite content of the soils derived from granitic bedrocks, while the soils derived from sedimentary bedrocks are abundant in residual illite.

• Economic and Environmental Geology
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• v.32 no.3
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• pp.293-306
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• 1999

The lower Permian jungseong Formation, Taebaegsan basin (Baegunsan Syncline), represents a coal-bearing siliciclastic succession which was later modified by the Songrim or Dabo orogeny. Sandstone perography and clay mineralogy were studied to understand the thermal history of the Jangseong Formation during basin evolution. Petrographic study indicates the Jangseong sandstones are composed of quartz, feldspar, lithic fragments (metamorphic and sedimetary), and varying proportions of matrix and cement. The dominance of quartz(<97%) over feldspar (<1%) and lithic fragments (<2%) classifies most Jangseong sandstones as quartz arenotes or quartzwackes, but lithic graywackes and sublithic arenite locally occur. The diagentic features of these sandstones include mechanical compaction, cemenation by quartz and clay minerals indentified in the Jangseong Formation by X-ray diffraction analysis are late-stage clay pore-filling. Clay minerals isdentified in the Jangseong Formation by X-ray diffaction analysis are illite, kaolinte, and pyrophyllite with a minor amount of chlorite and micas. The illite, kaolinite, and pyrophyllite appear to be largely autjigenic based on their well-crystallinity forms. There authigenic clay minerals form clay minerals form clay coats/rims and late-stage pore-filling cements, Illitecrystallinity shows that the Jangseong formation has been in late-diagenetic zone to early-epizone, which ranges in temperature from $200^{\circ}C$ to $300^{\circ}C$. In assition, kaolinite-pyrophyllite transition suggests that paleotemperature of the formation has reached at least $265^{\circ}C$. Such temperatureis likely to be consistent with homogenixation temperatures of fluid inclusions in quartz veins in the formation. Thus, the Jangseong Formation has been subjected to paleotemperature of about $265^{\circ}C$. The major heat source responsible for paleotemperature may be hydrothermal solutions. The passage of hydrothermal solutions was probably assisted by fractures created during the basin-modifying tectonism of the taebaegsan basin.

• 한국해양학회지
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• v.30 no.4
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• pp.271-278
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• 1995

A study of heavy mineral sands in terms of heavy mineral group and concentration has been carried out by analyzing 88 grab samples from the continental shelf off the southeast coast of Korea. Heavy mineral groups seem to be outlined and classified into four regions in the study area: 1) the western region; high concentrations of stable minerals, such as opaque mineral, magnetite, garnet and ZTR, 2) Korean Trough region; moderate concentrations of stable minerals, 3) the eastern region; abundant altered mineral and amphibole with minor of pyroxene concentration, and 4) the northeastern shelf-break region; low concentration of stable minerals with abundant altered minerals. The sedimentologic natures of four major heavy mineral regions (groupings) seem to be influenced by physical, dynamic and hydraulic milieu and also aerial and/or subaqueous weathering processes. It seems to be, further, plausible that shallow marine waves and currents associated with neritic dynamic condition of transgressive sea might be very effective on the concentration and groupings (sorting) of heavy min-erals in the surficial sediments of the continental shelf. The pyroxene-abundant heavy mineral suite (group), in fact, seems to suggest a sediment source from Japanese Islands.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.649-652
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• 2009

Nutritional compositions in edible portion of Castanopsis cuspidata seeds were investigated. Moisture content of Castanopsis cuspidata was 24.72 (Wt. %), crude protein was 2.19% (Wt. %), crude lipid was 0.83% (Wt. %), ash was 1.04% (Wt. %), and carbohydrate was 52.63% (Wt. %) in Castanopsis cuspidata seeds. Major amino acids were glutamic acid, aspartic acid, arginine and histidine, and minor ones were alanine, serine, proline, and valine. Sucrose was the highest content of free sugar in the seed. Major fatty acids were linolenic acid (18:3), palmitic acid (16:0) and oleic acid (18:1). Major minerals were P, K, Mg, Zn and Ca at the level of 88.31, 26.00, 13.20, 10.90, and 3.93 mg/100 g, respectively.

• Journal of Wetlands Research
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• v.23 no.3
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• pp.213-223
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• 2021

To understand the sedimentary environment of Scirpus planiculmis habitat (Myeongji and Eulsuk tidal flats) in the Nakdong Estuary, this study analyzed the statistical parameters (sorting, skewness, and kurtosis) of grain size data and the major (Al, Fe, Mn, Mg, Ca, Na, K, Ti, and P), minor (Li, Sc, V, Cr, Co, Ni, Cu, Zn, Sr, Zr, Cs, Pb, Th, and U), and rare earth elements (REEs) in sediment cores. For Myeongji, the sediment structure of the upper part of the cores was poorly sorted, more finely skewed, and more leptokurtic due to construction of the West gate. By contrast, the Eulsuk cores all differed due to the contrasting floodgate operation patterns of the West and East gates. The linear discriminate function (LDF) results corresponded to the statistical parameters for grain size. At the Eulsuk tidal flat (sites ES05 and ES11), elemental distributions were representative of Al-, Fe- and Ca-associated profiles, in which the elements are largely controlled by the accumulation of their host minerals (such as Na- and K-aluminosilicate and ferromagnesium silicate) and heavy detrital minerals at the sites. Detrital minerals including the aluminosilicates are major factors in the elemental compositions at ES05, diluting the REE contents. However, clay minerals and Fe-oxyhydroxides, as well as REE-enriched heavy minerals, appeared to be controlling factors of the elemental composition at ES11. Therefore, the mineral fractionation process is important in determining the elemental composition during sedimentation, which reflects the depositional condition of riverine-saline water mixing at both sites.

• Economic and Environmental Geology
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• v.31 no.4
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• pp.297-310
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• 1998

Geochemical characteristics of environmental toxic elements at the Narim mine area were investigated on the basis of major, minor, rare earth element geochemistry and mineralogy. Ratios of $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ in soils and sediments range from 11.57 to 22.21 and from 1.86 to 3.93, and are partly negative and positive correlation against $SiO_2/Al_2O_3$ (3.41 to 4.78), respectively. These suggested that sediment source of host granitic gneiss could be due to rocks of high grade metamorphism originated by sedimentary rocks. Characteristics of some trace and rare earth elements of V/Ni (0.33 to 1.95), Ni/Co (2.00 to 6.50), Zr/Hf (11.27 to 53.10), La/Ce (0.44 to 0.55), Th/Yb (4.07 to 7.14), La/Th (2.35 to 3.93), $La_N/Yb_N$ (6.58 to 13.67), Co/Th (0.63 to 2.68), La/Sc (3.29 to 5.94) and Sc/Th (0.49 to 1.00) are revealed a narrow range and homogeneous compositions may be explained by simple source lithology. Major elements in all samples are enriched $Al_2O_3$, MgO, $TiO_2$ and LOI, especially $Fe_2O_3$ (mean=7.36 wt.%) in sediments than the composition of host granitic gneiss. The average enrichment indices of major and rare earth elements from the mining drainage are 2.05 and 2.91 of the sediments and are 2.02 and 2.60 of the soils, normalizing by composition of host granitic gneiss, respectively. Average composition (ppm) of minor and/or environmental toxic elements in sediments and soils are Ag=14 and 1, As=199 and 14, Cd=22 and 1, Cu=215 and 42, Pb=1770 and 65, Sb=18 and 3, Zn=3333 and 170, respectively, and extremely high concentrations are found in the subsurface sediments near the ore dump. Environmental toxic elements were strongly enriched in all samples, especially As, Cd, Cu, Pb, Sb and Zn. The level of enrichment was very severe in mining drainage sediments, while it was not so great in the soils. Based on the EPA value, enrichment index of toxic elements is 8.63 of mining drainage sediments and 0.54 of soils on the mining drainage. Mineral composition of soils and sediments near the mining area were partly variable being composed of quartz, mica, feldspar, amphibole, chlorite and clay minerals. From the gravity separated mineralogy, soils and sediments are composed of some pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, goethite and various hydroxide minerals.