• Geomechanics and Engineering
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• v.20 no.6
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• pp.537-546
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• 2020

Oil and natural gas reserves have been recognised abundantly in clayey rich rock formations in deep costal reservoirs. It is necessary to understand the sedimentary history of those reservoir rocks to well explore these natural resources. This work designs a group of laboratory experiments to mimic the physical process of the sedimentary clay-rich rock formation. It presents characterisation results of the physical properties of the artificial clayey rocks synthesized from illite clay, quartz sand and brine water by high-pressure consolidation tests. Special focus is given on the effects of illite clay content and high-stress consolidation on the physical properties. Multi-step loaded consolidation experiments were carried out with stress up to 35 MPa on mixtures constituting of the illite clay, quartz sand and brine water with five initial illite clay contents (w=85%, 70%, 55%, 40% and 25%). Compressibility and void ratio were characterised throughout the physical compaction process of the mixtures constituting of five illite clay contents and their water permeability was measured as well. Results show that the applied stress induces a great reduction of clayey rock void ratio. Illite clay contents has a significant influence on the compressibility, void ratio and the permeability of the physically synthesized clayey rocks. There is a critical illite clay content w=70% that induces the minimum void ratio in the physically synthesised clayey rocks. The SEM study indicates, in the high-pressure synthesised clayey rocks with high illite clay contents, the illite clay minerals are located in layers and serve as the material matrix, and the quartz minerals fill in the inter-mineral pores or are embedded in the illite clay matrix. The arrangements of the minerals in microscale originate the structural anisotropy of the high-pressure synthesised clayey rock. The test findings can give an intuitive physical understanding of the deep-buried clayey rock basins in energy reservoirs.

• Journal of the Mineralogical Society of Korea
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• v.32 no.1
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• pp.51-61
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• 2019

Clay minerals, a major component of mud volcano (MV) sediments, are expected to provide important information for characterizing mud volcano formation mechanisms, but clay minerals have rarely been studied. The purpose of this study is to investigate the characteristics of 420 MV and surrounding marine sediments. Clay minerals and grain size were analyzed for 8 box cores from 420 MV and Mackenzie Trough. The relative proportions of the four major clay minerals in the Mackenzie Trough are almost constant in the order of illite, chlorite, kaolinite, and smectite, regardless of the distance from the Mackenzie River. However, the grain size tends to become fining as they move away from the Mackenzie River. Comparing the clay mineral characteristics of river (Colville River, Kuparuk River, Sagavanirktok River, Canning River, Mackenzie River) sediments entering the Beaufort Sea in order to determine the origin of the Mackenzie Trough and 420 MV sediments, the sediments of the Mackenzie Trough are characterized mainly by the Mackenzie River with a low ratio of smectite/illite and a high ratio of kaolinite/chlorite. In 420 MV sediments, the contents of clay minerals decrease in the order of illite, kaolinite, chlorite, and smectite, and the grain size with depth is almost constant. The content of smectite and coarse sediments is about two times higher than the reference core. No river with higher kaolinite content than chlorite exists in the Beaufort Sea, and the ratio of smectite/illite to kaolinite/chlorite is different from the reference core such as the ratio of the Mackenzie River. Compared to the reference core, the high contents of coarse sediments and the constant grain size with depth might be attributed to the ejection by MV. The reference core is interpreted as originating from Mackenzie River, and sediment of 420 MV is interpreted as originating from eruption of MV.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.259-268
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• 1988

Clay deposits in the vicinity of the Gwangpo Bay, southern coast of Korea, occur restrictively in anorthositic masses. Laumontite and meta-halloysite are the predominant clay minerals with iron oxides at the uppermost surface. Chlorite and halloysite occur in deeper zone. Beneath the main clay horizon, but not above, some anorthositic rocks are pervasively altered to quartz, sericite, chlorite, pyrite and montmorillonite along the hydrothermal channels. The hypotheses of hydrothermal and weathering origins of the clay minerals are tested by multi-component equilibrium calculations of the reactions of modified hydrothermal water and rain water with anorthositic rocks at $100^{\circ}C\;and\;25^{\circ}C$, respectively. The calculated mineralogy from the reaction with rain water resembles natural mineral assemblage except for abundance in laumontite. The result implies that the weathering process is the main machanism of the formation of clay deposits in the area.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.55-61
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• 2012

The ability of clay mineral to remove non-point sources such as SS, COD, T-N. T-P in the urban runoff has been tested to develop the porous filter material. The diameter of 3mm ball type filters were made of clay minerals for the tests. The experiments were carried out to measure the concentration of non-point sources of contaminants with flow rate of effluents. The test results show that clay filter has good response to remove SS, COD comparing to those of activated carbon filter. Also the performance of the clay filter to remove T-N and T-P is almost the same when using the activated carbon filter.

• 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.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.215-225
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• 2011

Metakaolin is a dehydroxylated form of the clay mineral kaolinite. Rocks that are rich in kaolinite are known as china clay or kaolin, traditionally used in the manufacture of porcelain. The particle size of metakaolin is smaller than cement particles, but not as fine as silica fume. This paper investigates the effect of the concrete containing metakaolin as a mineral admixture on the compressive strength and resistance properties to chloride ion penetration. In this study, the experiment was carried out to investigate and analyze the influence of replacement ratio of metakaolin and micro silica fume on the compressive strength and chlorine ion penetration resistance of concrete. All levels were water/binder ratio 30%, replacement ratio of metakaolin and silica fume were 0, 5, 10, 15, 20% respectively. The compressive strength of concrete using metakaolin tends to increase, as the replacement ratio increases but the chlorine ion penetration resistance was not so as lager as silica fume concrete. Therefore, the optimum mixing ratio of metakaoline to satisfy a properties of compressive strength and chlorine ion penetration resistance was was approximately10%.

• Journal of the Mineralogical Society of Korea
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• v.30 no.4
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• pp.161-172
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• 2017

Clay minerals play a major role in the geochemical cycles of metals in the Critical Zone, the Earth surface-layer ranging from the groundwater bottom to the tree tops. Atomistic scale research of the very fine particles can help understand the fundamental mechanisms of the important geochemical processes and possibly apply to development of hybrid nanomaterials. Molecular dynamics (MD) simulations can provide atomistic level insights into the crystal structures of clay minerals and the chemical reactivity. Classical MD simulations use a force field which is a parameter set of interatomic pair potentials. The ClayFF force field has been widely used in the MD simulations of dioctahedral clay minerals as the force field was developed mainly based on dioctahedral phyllosilicates. The ClayFF is often used also for trioctahedral mineral simulations, but disagreement exits in selection of the interatomic potential parameters, particularly for Mg atom-types of the octahedral sheet. In this study, MD simulations were performed for trioctahedral clay minerals such as brucite, lizardite, and talc, to test how the two different Mg atom types (i.e., 'mgo' or 'mgh') affect the simulation results. The structural parameters such as lattice parameters and interatomic distances were relatively insensitive to the choice of the parameter, but the vibrational power spectra of hydroxyls were more sensitive to the choice of the parameter particularly for lizardite.

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.83-93
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• 2015

This study investigated genetic, mineralogical and spectral characteristics of oil shale and coal samples in Dundgobi area, Mongolia. Based the Rock/Eval and Total organic carbon (TOC) analysis, kerogen type, hydrogen quantity, thermal maturity and depositional environment were confirmed. Moreover, the mineral composition of oil shale and coal samples were analyzed by XRD and spectroscopy. The result of Rock Eval/TOC analysis revealed that the samples of Eedemt deposit are immature to mature source rocks with sufficient hydrocarbon potential, and the kerogen types were classified as Type I, Type II and Type III kerogen. On the other hand, the samples from Shine Us Khudag deposit were mature with good to very good hydrocarbon potential rocks where kengen types are defined as Type I, Type II/III and Type III kerogen. According to the carbon and sulfur contents, the depositional environment of the both sites were defined as a freshwater depositional environment. The XRD analysis revealed that the mineral composition of oil shale and coal samples were quartz, calcite, dolomite, illite, kaolinite, montmorillonite, anorthoclase, albite, microcline, orthoclase and analcime. The absorption features of oil shale samples were at 1412 nm and 1907 nm by clay minerals and water, 2206 nm by clay minerals of kaolinite and montmorillonite and 2306 nm by dolomite. It is considered that spectral characteristics on organic matter content test must be tested for oil shale exploration using remote sensing techniques.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1188-1195
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• 1999

This study was conducted to determin basic mineral compositions, chemical components, description of particle size distribution and whiteness for 32 items of insoluble mineral substances, i.e., 3 items of diatomaceus earth, 1 item of kaolin, 10 items of bentonite, 13 items of acid clay, 3 items of talc and 2 items of perlite. The chemical components and XRD (X-Ray diffractometer) for insoluble mineral substances, were similar with those of the reported references except kaolin. However, whiteness was determined in 90% level for talc, diatomaceus earth and kaolin. The contents of heavy metals in insoluble mineral substances were determined as follows : Pb, $nd{\sim}23.10$ ppm ; Cd, $nd{\sim}0.67$ ppm ; Hg, $nd{\sim}0.58$ ppm ; As, $nd{\sim}1.42$ ppm ; Cu, $nd{\sim}39.35$ ppm. These data were significanty lower than the references.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.393-398
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• 2008

Several researchers have proposed models or equations to predict soil $CO_2$ flux from more readily available biotic and abiotic measurement. Tree commonly used abiotic variables were N mineral and soil temperature and soil water content. This study was conducted to determine $CO_2$ emission to mineral N, soil water content and soil temperature with clay loam and sandy loam in pepper cultivation in 2004~2005. $CO_2$ flux in the upland with different levels of soil water potential was measured at least once in two weeks during the cropping period in the pepper cultivation plots. Soil water potential in the clay loam and sandy loam soils was established at -30kPa and -50kPa by measuring the soil gravimetric water content with two replications. $CO_2$ emission rate from the differently managed plots was highly correlation coefficient to between the mineral N ($R=0.830^{**}$, $0.876^{**}$) and soil temperature ($r^2=0.793^{**}$, $0.804^{**}$) in the clay loam and sandy loam, respectively. However, the relationships between $CO_2$ emission and soil water content were non-significant. $CO_2$ emissions at sandy loam soils was lower to 21~37% than at clay loam soils for both soil water conditions without differences in yield. At difference levels of soil water conditions, $CO_2$ emission at -50kPa decreased to 37.5% in comparison with that at -30kPa. From the path analysis as to contribution factors of GHGs, it appeared that contribution rate was in the order of soil temperature (54.9%), mineral N (32.7%), and soil moisture content (12.4%).