• Title/Summary/Keyword: Clay

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Hampyong, Kyochon Clay-Its Characteristics and the Effects of Clay-organic Complexes on its. (함평, 교촌 점토의 특성과 점토-유기물 복합체에 관한 연구)

  • 정창주;백용혁;박현수
    • Journal of the Korean Ceramic Society
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    • v.14 no.2
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    • pp.95-103
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    • 1977
  • Characteristics of Ham Pyong clay and clay-organic complexes were investigated by means of geological exploration, chemical analysis, X-ray diffraction, differential thermal analysis, electron microscopy, thermal mechanical analysis, cation exchange capacity and viscosity measurement. The results are as follows; 1) This caly is a transported clay which has black and white colors, and the amounts of deposit are estimated about 1, 600, 000M/T. 2) The major mineral phases identified by X-ray diffraction are kaolinite, sericite and halloysite and the minor phases are quartz and feldspar, these mineral phases can be seperated very easily by the elutriation method. 3) It was supposed that the black colored clay involved a certain clay-organic complexs by the mechanism of intercalation as well as surface absorption. 4) The clay-organic complexes in clay seemed to improve dispersity, to increase the fluidity of clay-water slips, to decrease the firing shrinkage and to promote the thermo-chemical reaction at temperature range up to 50$0^{\circ}C$, but not to effect on the resulted firing color.

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Evaluation of the engineering property of clay minerals nearby seoul area as clay liner material (수도권 주변 점토광물의 점토차수벽 물질로의 유용성 평가)

  • 오석영
    • Economic and Environmental Geology
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    • v.32 no.2
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    • pp.151-159
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    • 1999
  • This research was carried out to evaluate the possible usage of natural clay materials collected from the Kimpo landfill site and nearby clay mines as a clay liner material. In order to evaluate the possible usage as a clay liner material, specific gravity, pH, loss-on-ignition, organic carbon content and mineralogical composition of clay materials were measured. The Atterberg limit test and the size analysis were performed for the engineering classification and the prediction of hydraulic conductivity of clay materials. Caution exchange capacity and batch tests were also carried out for the assessment of attenuation capacity. Clay specimens of KPNCL, KP-1, KP-2 and SH were recommended as suitable clay linder materials from viewpoint of their basic quality and attenuation capacity.

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A Study on the Mechanical Properties of Molding Sand with various Water/Clay Ratio. (수분(水分) : 점토비(粘土比)에 따른 주물사(鑄物砂)의 기계적(機械的) 성질(性質)에 관한 연구(硏究))

  • Lee, Kye-Wan;Lee, Choo-Lim
    • Journal of Korea Foundry Society
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    • v.4 no.2
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    • pp.89-95
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    • 1984
  • A Study on the Mechanical Properties of Molding Sand with Various Water/Clay Ratio A standard sample of molding sand was prepared by adding a various amount of bentonite, which has water/clay ratio from 0.4 to 0.6, into artificial sand, Hanyoung #6. The results obtained by measuring the room temperature properties of green mold are as follows. 1. This compressive strength of green molds which have 4% and 10% of bentonite decreased with increasing water/clay ratio, but the maximum strengths of 4.3 (psi) and 7.2 (psi) were observed in the samples with 6%, 8% bentonite respectively when the water/clay is 0.45. 2. The optimum water/clay ratio for strength and permeability increased from 0.4 to 0.5 with increasing clay. 3. The green compressive strength was proportional to the hardness. 4. Deformation increased with increasing water/clay ratio. 5. Flowability decreased with increasing water/clay ratio and clay content in molding sand.

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Synthesis and Properties of Environmentally-friendly Aqueous Polyurethane Dispersion/Clay nanocomposites (환경친화적 수분산성 폴리우레탄/Clay 나노복합체의 제조 및 물성에 관한 연구)

  • Dan, Cheol Ho;Kim, Jeong Ho
    • Clean Technology
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    • v.12 no.1
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    • pp.11-18
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    • 2006
  • In this study, aqueous polyurethane dispersion(PUD) was synthesized using polyhexamethylene carbonate glycol (PHMCG) as soft segment, isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as hard segment. Also, polyurethane/clay nanocomposites were prepared by adding pristine montmorillonite (PM) and organically modified clays, C15A and C30B into PUD. The degree of clay dispersion in the nanocomposites was investigated using XRD and the physical and thermal properties were examined through UTM and TGA. These results showed that nanocomposites with C15A gave higher physical and thermal properties than those with C30B or PM. As a result, the properties of nanocomposites were observed to vary depending on the types of clay modifiers and clay contents.

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Effect of Yellow Clay on the Oxygen Consumption Rate of Korean rockfish, Sebastes schlegelii

  • Lee, Chang-Kyu;Kim, Wan-Soo;Park, Young-Tae;Jo, Q-Tae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.3
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    • pp.241-247
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    • 2013
  • Yellow clay dispersion has been applied to minimize fisheries impact by the red tide Cochlodinium polykrikoides blooms in Korean coasts since 1995. The present preliminary study documents the effect of yellow clay on Korean rockfish, Sebastes schlegelii, in terms of oxygen consumption rate (OCR). The OCR in the low clay suspension (0.05 and 0.23 %, w/w) showed normal level compared to the control. In contrast, the OCR for each one of three replicates in the high clay suspension (1.16 and 5.58 %, w/w) was not returned to the previous level that clay was not treated, indicating that high clay suspension (${\geq}1.16%$, w/w) might give negative effect on Korean rockfish. Overall, this result suggests that field application of clay to control Harmful Algal Blooms (HABs) may not give impact on Korean rockfish once the clay is dispersed in a low concentration (${\leq}0.23%$). In order to understand the changes of OCR in the repeated exposure to clay, it is required to do further studies on the changes of OCR when the fish is exposed to clay repeatedly after recovery in the normal seawater.

Mechanical Property of Clay-polymer Nanofiber Composite Membrane (Clay를 함유한 Polysulfone 나노섬유 복합막의 제조 및 물리적 특성 연구)

  • Park, Yeji;Yun, Jaehan;Byun, Hongsik
    • Membrane Journal
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    • v.27 no.3
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    • pp.284-289
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    • 2017
  • In this study, natural clay as a filler was systematically integrated into polysulfone nanofibers to prepare polysulfone/clay composite membranes with mechanical properties. The composite nanofibers were formed by electrospinning of a mixed precursor of polysulfone and clay. The pore size of the composite membranes was adjusted by simply controlling the number of layers of nanofibers. The overall membrane properties were examined by SEM, contact angle, pore characteristics, tensile strength and water flux. In particular, the presence of clay within the nanofibers was confirmed with SEM images and the mechanical property of the composite nanofiber membranes was examined by tensile strength measurements. Thus, the prepared composite membranes were expected to be utilized for water treatment system.

Development of $Al_2TiO_5$-Clay Composites for Infrared Radiator ($Al_2TiO_5$-점토 복합체를 이용한 적외선 방사체의 개발)

  • 신대용;한상목
    • Journal of the Korean Ceramic Society
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    • v.37 no.2
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    • pp.122-127
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    • 2000
  • The thermal expansion, thermal stability, mechanical strength and infrared radiative property of Al2TiO5-clay composites, prepared from synthesized Al2TiO5 and clay, were investigated to develop a material for far infrared radiators. The emittance of composites containing 10~50 wt% clay, heated at 1,20$0^{\circ}C$ for 3 h, increased with increasing clay content and emittance was about 0.3 and 0.92 in the ranges of 3,400~2,500 cm-1 and 2,500~400cm-1, respectively. The bulk density and bending strength of the Al2TiO5-clay composites increased with increasing clay content. 50 wt% Al2TiO5-50 wt% clay composite, heat-treated at 1,20$0^{\circ}C$, had an adequate strength for infrared radiators; 80 MPa. The degree of thermal expansion hysteresis decreased with increasing clay content and the mean thermal expansion coefficient increased with increasing clay content. The thermal expansion coefficient of 50 wt% Al2TiO5-50 wt% clay composite heated at 1,20$0^{\circ}C$ was 5.78$\times$10-6/$^{\circ}C$.

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Inhibitory Effect of Benzoate-intercalated Hydrotalcite with Ce3+-loaded clay on Carbon Steel

  • Thuy Duong Nguyen;Thu Thuy Pham;Anh Son Nguyen;Ke Oanh Vu;Gia Vu Pham;To Thi Xuan Hang
    • Corrosion Science and Technology
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    • v.22 no.1
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    • pp.1-9
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    • 2023
  • This work studied the inhibitory effect of the combination of benzoate-intercalated hydrotalcite (HT-BZ) and Ce3+-loaded clay (Clay-Ce) on carbon steel (CS). HT-BZ was prepared by the co-precipitation method and Clay-Ce was fabricated by a cation exchange reaction. HT-BZ and Clay-Ce were assessed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) coupled with zeta potential measurement. Electrochemical measurements coupled with scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) were used for studying the inhibitory action of the mixture of HT-BZ and Clay-Ce on steel electrodes immersed in 0.1 M NaCl. For comparison, the inhibitory effect of HT-BZ or Clay-Ce alone was also evaluated. The results showed that HT-BZ combined with Clay-Ce provided synergistic inhibition of the CS substrate. The mixture of 0.5 g/L HT-BZ + 0.5 g/L Clay-Ce provided 93.5% inhibition efficiency. The protective mechanism of the HT-BZ + Clay-Ce mixture consisted of the reaction of released BZ and Ce3+ and the deposition of HT-BZ and Clay-Ce structures on the CS substrate.

A Study on the Infrared Emission Properties and Freeze-thaw Resistance for Calcined Clay by Carburization Treatment (소성 점토의 침탄에 따른 동결융해 저항성 및 적외선 방사특성 연구)

  • Kim, Ki-Ho;Kim, Sang-Myoung;Kang, Byung-Chul
    • Journal of the Korean Ceramic Society
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    • v.45 no.7
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    • pp.387-394
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    • 2008
  • The Physical property changes of calcined clay by carburization were investigated studied. The carburization mechanism is the penetration of carbon which occurred during incomplete fuel combustion into crevice of clay structure. The experiments for elasticity and freeze-thaw resistance were conducted, and the results can be summarized as follows: Dynamic modulus of elasticity and also freeze-thaw resistance of calcined clay by carburization treatment increased more than 92% after testing 300 cycle, which was more improved than 88% of calcined clay. Therefore, it can decrease the possibility of winter-sowing, which is one the weakness of calcined clay. It is on the basis of the fact that the porosity of calcined clay by carburization treatment is about 12%, which indicates smaller pore spaces comparing with the 14% of porosity of calcined clay and those values were calculated by apparent porosity show and also supported by SEM images. Infrared emissivity of calcined clay by carburization treatment and calcined clay were respectively 0.92 and 0.9l at $80^{\circ}C$. However, those values were 0.91 and 0.88 at $200^{\circ}C$, which means infrared emissivity of calcined clay by carburization treatment shows 3.6% higher than the calcined clay. Moreover, within the wavelength range from 3 to $7\;{\mu}m$, while the calcined clay had low infrared emissivity, the calcined clay by carburization treatment had increased infrared emissivity. It is inferred that it was affected by carbon element that has high infrared absorptivity within this wavelength range.

STRENGTH CHANGES OF SURROUNDING CLAY DUE TO SOIL-CEMENT COLUMN INSTALLATION

  • Miura, Norihiko
    • Proceedings of the Korean Geotechical Society Conference
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    • 1997.10a
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    • pp.19-36
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    • 1997
  • This paper discusses the reduction and subsequent recovery and increase of shear strength of clay in the vicinity of soil-cement column. Laboratory and field tests were conducted to investigate the effects on surrounding clay during and after soil-cement column installation in soft Ariake clay. Discussions were made on the mechanism of strength changes of clay by considering the thixotropic recovery, reconsolidation effect, penetration of cement slurry and diffusion of exchangeable cations. On the basis of field and laboratory observations, 10 days after column installation, the decreased shear strength of surrounding clay during mixing was recovered and 30 days later, shear strength of surrounding clay increased 30% by average. Therefore, it is recommended that the increase of shear strength of clay can be taken into consideration in the bearing capacity and stability analysis of the composite ground.

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