• Title/Summary/Keyword: Kaolin

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Mineralogical Characteristics and Designation of Key Beds for the Effective Surveys of the Jeonnam Pyrophyllite Deposits (전남일원 납석광상의 광물학적 특성과 효과적 탐사를 위한 Key Beds의 선정)

  • Yoo, Jang-Han;Kim, Yong-Ug;Lee, Gill-Jae
    • Journal of the Mineralogical Society of Korea
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    • v.22 no.4
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    • pp.297-305
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    • 2009
  • Ores of the Jeonnam pyrophyllite province mainly consist of not only pyrophyllite but also kaolinite, and they usually contain minor amounts of muscovite and quartz. We usually call them as porcelaneous stones which usually show lower grade characteristics in the viewpoint of Korean nonmetallic industries. Mineralogical studies for the ores and their intimate formations revealed that another kind of clay minerals could have been produced from the volcanic sediments with similar ages and compositions. Corundum is commoner than the diaspore in the pyrophyllite deposits, and so diaspore can be regarded as one of temporary minerals from which corundum would be finally formed. Kaolinite deposits contain neither diaspore nor corundum, but alunites produced by an advanced argillic alteration are often observed in the upper portions of the kaolin ores. The lowest formation interbedded with pyrophyllite and/or kaolinite ores usually contain purple tuff bed on the uppermost part, and in ascending order, siliceous formation, fine ash tuff and lapillistone are found in the study areas. As ages are becoming younger, amounts of pyrophyllite and kaolinite are radically decreased, or disappeared completely. On the other hand, content of muscovite is slightly increased, and those of plagioclase feldspars and quartz are found to have been preserved from the original rocks during alteration process. Most of ore bodies show rather well bedded formations which are easily discernable in the outcrops, but more effective discremination is desirable where rather massive ores exist. Siliceous beds and purple tuff ones on the upper part of ore bodies would be useful as marker horizons or key beds which have distinct lithologies and extensions.

Investigation on Natural Radioactivity of Environmental Samples Near the Bauxite Processing Facility (보오크사이트 사용업체 주변 환경시료의 자연방사능 조사)

  • Moon, Dong-Hyeok;Koh, Sang-Mo;Chang, Byung-Uck;Kim, Tong-Kwon;Kim, Yong-Ug
    • Journal of the Mineralogical Society of Korea
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    • v.23 no.4
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    • pp.347-356
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    • 2010
  • Bauxite is a main raw material for the production of alumina and aluminum hydroxide in the processing plant of KC company. It is a NORM (Naturally Occurring Radioactive Materials), and its waste, red mud, is a TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials). The purpose of the geochemical and mineralogical investigations of the bedrock and soils in and around the plant, a large NORM source, was to provide basic data for measuring the radiation dose and protecting from radioactive hazards. Soils were mixtures of minerals derived from the country rock (quartz, feldspar, mica, kaolin, gibbsite, and sepiolite) and bauxite (hematite, boehmite, and calcite) of open-air storage. Average U and Th contents of the soil samples were 4.7 ppm and 23 ppm, respectively, indicating somewhat Th anomaly. The average concentrations of radionuclides are $^{40}K$ 100~1,433 Bq/kg, $^{226}Ra$ anomaly in the red mud open-air storage. Soil external hazard indices range from 0.10 to 1.66 with an average of 0.63. Although most of the indices are below 1.0 that is a regulation value, those of 4 samples of total 41 soil samples exceed 1.0, requiring further detailed investigation.

A Study on the Characterization of Anthracite Fly Ash for the Fabrication of Calcinated Brick (소성블릭 제조를 위한 무연탄 석탄회의 특성 연구)

  • Yu Yeon-Tae;Kim Byoung-Gyu;Choi Young-Yoon;Nam Chul-Woo;Lee Yeng-Seok;Kim Cheon-Sun
    • Resources Recycling
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    • v.13 no.2
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    • pp.16-23
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    • 2004
  • To increase the recycling rate of anthracite fly ash, the properties of anthracite fly ash were compared to that of bituminous fly ash. Especially, the high temperature properties of the fly ash are investigated by using thermal analysis, high temperature microscope and X-ray diffraction analysis for utilizing anthracite fly ash to prepare the calcinated bricks. The average ratio of $A1_2$$O_3$/$SiO_2$ for anthracite is 0.62 and the ratio for bituminous is 0.34. The content of $SiO_2$ in anthracite fly ash was higher than that of bituminous fly ash. The $A1_2$$O_3$ of anthracite fly ash reacted with the $A1_2$$O_3$ in the fly ash and formed new mullite crystal at over $1000^{\circ}C$, so anthracite fly ash showed high fire resistance. And, the fly ash mixtures having kaolin were prepared, and then extruded in vacuum to evaluate the extruding property of anthracite fly ash mixture. The extruding velocity was decrease with increasing the addition amount of fly ash in the mixture, and the maximum addition amount of fly ash that could be extruded was 60 wt%.

Mineralogical Characteristics of Lime Mortars Used in Pointing of Namhansanseong Yeojang in Joseon Dynasty (남한산성 여장의 사춤으로 사용된 조선시대 석회 모르타르의 광물학적 특성 연구)

  • Kim, Eunkyung;Ahn, Sunah;Mun, Seongwoo;Kang, Soyeong
    • Journal of the Mineralogical Society of Korea
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    • v.30 no.4
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    • pp.179-186
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    • 2017
  • This study investigated the mineralogical characteristics of lime mortars used in pointing of Namhansanseon Yeojang from Joseon dynasty. Polarization microscopy revealed quartz, feldspar, mica, pyroxene and opaque minerals in the lime mortars. XRD analysis also confirmed clay minerals chlorite and kaolin. As a result of particle size analysis of lime mortars, the particle size distribution was wide and size was not uniform. 60% of samples were corresponded to the sand area. The chemical components detected from XRF analysis, 8.71-11.18 % of Ca as the main component of lime and $SiO_2$, $Al_2O_3$, and $Fe_2O_3$ in soil minerals were main components. The lime mortars showed an endothermic peak due to decarbonization reaction of $CaCO_3$ at $750^{\circ}C$ and weight reduction rate of 10%. The microstructures were agglomerated amorphous and observed rhombohedral calcite crystals by scanning electron microscope. It is considered that the pointing of Yeojang is a mortar mixed with lime and soil. In addition the Hanbongseong Yeojang was constructed using the same materials and construction technique because the minerals composition is not different according to the Yeojang location and use.

Interpretation of Construction Procedure and Physicochemical Characteristics for Soil Layers from Sowangneung (Small Royal Tomb) of Ssangneung (Twin Tombs) in Iksan, Korea (익산 쌍릉 소왕릉 봉분 토층의 물리화학적 특성과 조영과정 해석)

  • Chae, Joon;Park, Seok Tae;Cho, Ji Hyun;Lee, Chan Hee
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.748-766
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    • 2021
  • The Iksan Ssangneung (twin tombs), a pair of tombs comprising the Daewangneung (large royal tomb) and the Sowangneung (small royal tomb), were constructed in the typical style of stone tunnel and chamber tombs in the Baekje Kingdom during the Sabi period (538 to 660 AD) of ancient Korea. Soil layers exposed during excavation of Sowangneung in a trench east of the tomb are: the bottommost layer, the ground level layer, the Panchuk (rammed earth) layer of the Baekje, the layer created by a grave robbery, and soil recovered during the Japanese colonial period. Soil samples were obtained by segmenting an easy stratigraphic horizon into sub categorized soil layers, and their material properties were analyzed; they are composed mainly of sandy loam based on the particle size distributions. In the site foundation, loamy sand is packed in the bottommost layer, and sandy loam with high sand and silty sand fills most of the overlying layer. The central and topmost portion of the Baekje layer is composed of loam with high clay content. All soil layers show geochemical behaviors similar to those of the bottommost layer. X-ray diffraction analysis verified kaolinite in all layers, also observed in soil layers displaying high crystallinity. Kaolinite and halloysite were identified by scanning electron microscopy. Thus, we conclude that the Baekje layer of the Sowangneung is composed of sandy loam containing kaolin procured from near the site. An impermeable middle to upper layer was created using viscous loam. The top of the tomb was closed tightly.

Mineralogy and Geochemistry of Shale Deposits in the Lower Anambra Basin, Nigeria: Implication for Provenance, Tectonic Setting and Depositional Environment

  • Olugbenga Okunlola;Agonsi Udodirim Lydia;Aliyu Ohiani Umaru;Raymond Webrah Kazapoe;Olusegun G. Olisa
    • Economic and Environmental Geology
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    • v.56 no.6
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    • pp.799-816
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    • 2023
  • Mineralogical and geochemical studies of shales within the Lower Anambra Basin was conducted to unravel the depositional environment, provenance, maturity, paleo-weathering conditions, and tectonic settings. Mineralogical studies conducted using X-ray diffraction analysis revealed that the samples were composed of kaolinite, montmorillonite, chlorite, and illite. KaolinIite is the dominant mineral, constituting approximately 41.5% of the bulk composition, whereas the non-clay minerals are quartz, ilmenite, and sillimanite. Geochemical analysis showed a predominance of SiO2, Al2O3, and Fe2O3 contents of the shale samples with mean values of 52.29%, 14.09%, and 6.15% for Imo Shale (IS); 52.31%, 16.70%, and 7.39% for Mamu Shale (MS); 43.21%, 21.33%, and 10.36% for Enugu Shale (ES); 53.35%, 15.64%, and 7.17% for Nkporo Shale (NS); and 51.24%, 17.25%, and 7.78% for Agwu Shale (AS). However, the shales were depleted in Na2O, MgO, K2O, MnO, TiO2, CaO, and P2O5. The trace element ratios of Ni/Co and Cu/Zn of the shale suggest an oxic depositional environment. The average SiO2 vs. Al2O3 ratio of the shales indicated textural maturity. Compared to the PAAS standard, the shales plot below the PAAS value of 0.85, suggesting a high degree of maturity and intensive chemical weathering, further confirmed on a CIA vs. PIA plot. On log (K2O/Na2O) against SiO2 and tectonic setting discriminant function diagrams, the shales plot mostly in the field of passive continental margin tectonic setting. The discriminant function diagrams as well as Al2O3/TiO2 ratio of the shales showed that they were derived from a mixed source (mafic and intermediate igneous rocks).

Transformation of Asbestos-Containing Slate Using Exothermic Reaction Catalysts and Heat Treatment (발열반응 촉매제와 열처리를 이용한 석면함유 슬레이트의 무해화 연구)

  • Yoon, Sungjun;Jeong, Hyeonyi;Park, Byungno;Kim, Yongun;Kim, Hyesu;Park, Jaebong;Roh, Yul
    • Economic and Environmental Geology
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    • v.52 no.6
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    • pp.627-635
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    • 2019
  • Cement-asbestos slate is the main asbestos containing material. It is a product made by combining 10~20% of asbestos and cement components. Man- and weathering-induced degradation of the cement-asbestos slates makes them a source of dispersion of asbestos fibres and represents a priority cause of concern. When the asbestos enters the human body, it causes cellular damage or deformation, and is not discharged well in vitro, and has been proven to cause diseases such as lung cancer, asbestos, malignant mesothelioma and pleural thickening. The International Agency for Research on Cancer (IARC) has designated asbestos as a group 1 carcinogen. Currently, most of these slats are disposed in a designated landfill, but the landfill capacity is approaching its limit, and there is a potential risk of exposure to the external environment even if it is land-filled. Therefore, this study aimed to exam the possibility of detoxification of asbestos-containing slate by using exothermic reaction and heat treatment. Cement-asbestos slate from the asbestos removal site was used for this experiment. Exothermic catalysts such as calcium chloride(CaCl2), magnesium chloride(MgCl2), sodium hydroxide(NaOH), sodium silicate(Na2SiO3), kaolin[Al2Si2O5(OH)4)], and talc[Mg3Si4O10(OH)2] were used. Six catalysts were applied to the cement-asbestos slate, respectively and then analyzed using TG-DTA. Based on the TG-DTA results, the heat treatment temperature for cement-asbestos slate transformation was determined at 750℃. XRD, SEM-EDS and TEM-EDS analyses were performed on the samples after the six catalysts applied to the slate and heat-treated at 750℃ for 2 hours. It was confirmed that chrysotile[Mg3Si2O5(OH5)] in the cement-asbestos slate was transformed into forsterite (Mg2SiO4) by catalysts and heat treatment. In addition, the change in the shape of minerals was observed by applying a physical force to the slate and the heat treated slate after coating catalysts. As a result, the chrysotile in the cement-asbestos slate maintained fibrous form, but the cement-asbestos slate after heat treatment of applying catalyst was broken into non-fibrous form. Therefore, this study shows the possibility to safely verify the complete transformation of asbestos minerals in this catalyst- and temperature-induced process.

Investigation on Natural Radioactivity of Environmental Samples Near the Phosphate Rock Processing Facility (인광석 사용업체 주변 환경시료의 자연방사능 조사)

  • Lee, Gill-Jae;Koh, Sang-Mo;Chang, Byung-Uck;Kim, Tong-Kwon;Kim, Young-Ug
    • Economic and Environmental Geology
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    • v.44 no.1
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    • pp.37-48
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    • 2011
  • Some industrial minerals used in domestic industries such as monazite, apatite, bauxite, and ilmenite belong to NORM (Naturally Occurring Radioactive Materials) because they show a high radioactivity. Products, semi-products, wastes, and by-products which show higher radioactivity than NORM belong to TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials). Apatite used for manufacturing phosphate fertilizer in Namhae Chemical company belongs to NORM, and its by-product, phospo-gypsum, belongs to TENORM. A geological investigation is needed for the future environmental impact assessment of the Namhae Chemical company's site. According to survey results of the Namhae Chemical company's site, soil mineral composition indicated the mixture of minerals derived from the country rock (quartz, feldspar, mica, $l4{\AA}$ mineral, kaolin and amphibole) and minerals from the gypsum open-air storage yard (gypsum and apatite). Soil samples showed average content of U 4.6 ppm and Th 10 ppm, which are similar to average crustal abundances. They also show average contents of $^{40}K$ 191-1,166 Bq/kg, $^{226}Ra$ 15.6-710 Bq/kg, and $^{232}Th$ 17.4-72.7 Bq/kg, which indicate moderate levels of radio nuclide. But $^{226}Ra$ anomaly in the gypsum open storage yard is clearly confirmed and $^{232}Th$ anomaly is also confirmed in the east road side of the factory and nearby mountain areas. Soil external hazard indices ranged 0.24-2.01 with the average 0.54. Although most external hazard indices were lower than 1, which means radiation hazard index to be negligible, 5 samples out of total 40 samples showed higher values than 1, and further detailed investigation is needed.

The Effects of Anoxic Treatments on Color and Mechanical Property in Fabrics, Natural Dyed Fabrics, Papers, Natural Dyed Papers and Paints (저산소 농도 살충처리가 직물, 염색 직물, 종이, 염색지 및 채색편의 색상 및 기계적 성질에 미치는 영향)

  • Oh, Joon Suk;Choi, Jung Eun;Noh, Soo Jung;Eum, Sang Wook
    • Journal of Conservation Science
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    • v.30 no.2
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    • pp.219-234
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    • 2014
  • Fabrics, natural dyed fabrics, papers, natural dyed papers and paints were examined effects of colors and mechanical properties for materials of museum collections under anoxic treatment. Anoxic conditions using nitrogen and argon were oxygen concentration 0.01%, temperature($20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$), 50% RH and exposure time 30 days. Examined fabrics were raw silk fabric, UV irradiated raw silk fabric, degummed silk fabric, UV irradiated degummed silk fabric, cotton fabric, and UV irradiated cotton fabric. Natural dyed silk and cotton fabrics were dyed with fresh indigo, indigo, safflower, gromwell, madder sappanwood, amur cork tree, turmeric, gardenia, barberry root, pagoda tree flower, cochineal, lac, alnus japonica, gallnut, chestnut shell, and combination(indigo and safflower, indigo and amur cork tree, indigo and pagoda tree flower, indigo and sappanwood). Papers were Korean papers(mulberry paper, mulberry(70%) and rice straw(30%) mixed paper), Japanese paper(gampi paper), cotton paper, refined linen paper, cotton, linen & manila mixed fibre furnish, copy paper, news print, and alum sized mulberry paper. Natural dyed papers were dyed with indigo, sappanwood, madder, safflower, gardenia, amur cork tree, and pagoda tree flower. Paints were painted on alum-sized papers and silk fabrics using glue and pigments(azurite, malachite, cinnabar, vermilion, orpiment, gamboge, red lead, haematite, iron oxide red, indigo(lake), lac, cochineal, safflower, madder root lake, celadonite, smalt, ultramarine blue, lapis lazuli, prussian blue, kaolin, lead white, oyster-shell white, and clam-shell white). The color differences(${\Delta}E^*$) of all examined materials were below 1.5 or lowered than control samples after anoxic treatment. The variations of tenacity of yarns of fabrics and natural dyed fabrics after anoxic treatment were within that of standard silk and cotton fabrics. Gases(nitrogen and argon) and temperatures of anoxic treatment did not also affected color differences and variations of tenacity of materials.

Origin of Clay Minerals of Core RS14-GC2 in the Continental Slope to the East of the Pennell-Iselin Bank in the Ross Sea, Antarctica (남극 로스해 펜넬-이젤린 퇴 동쪽 대륙사면의 코어 RS14-GC2의 점토광물의 기원지 연구)

  • Ha, Sangbeom;Khim, Boo-Keun;Cho, Hyen Goo;Colizza, Ester
    • Journal of the Mineralogical Society of Korea
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    • v.31 no.1
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    • pp.1-12
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    • 2018
  • A gravity core (RS14-C2) was collected at site RS14-C2 in the continental slope to the east of Pennell-Isellin Bank of the Ross Sea (Antarctica) during PNRA XXIX (Rosslope II Project) Expedition. In order to trace the sediment source, magnetic susceptibility (MS), sand fraction, and clay mineral compositions were analyzed, and AMS $^{14}C$ ages were dated. Core sediments consist mostly of hemipelagic sandy clay or silty clay including ice-rafted debris (IRD). AMS $^{14}C$ age of core-top indicates the modern and Holocene sediments. Based on AMS $^{14}C$ dating, sediment color, MS and sand fraction, core sediments are divided into interglacial and glacial intervals. The interglacial brown sediments are characterized by low MS and sand fraction, whereas the glacial gray sediments are characterized by high MS and sand fraction. Among clay mineral compositions of core sediments, illite is highest (61.8~76.7%), and chlorite (15.7~21.3%), kaolinite (3.6~15.4%), and smectite (0.9~5.1%) are in decreasing order, and these compositions are also divided into the interglacial and glacial/deglacial intervals. During the glacial period, the high content of illite and chlorite indicate sediment supply from the bedrocks of Transantarctic Mountains under the Ross Ice Sheet. In contrast, because of decreasing supply of illite and chlorite by the glacial retreat, smectite and kaolinite contents increased relatively during the interglacial period. During the interglacial period, smectite may be transported additionally by the northeastward flowing surface current from the coast of Victoria Land in the western Ross Sea. Kaolinite may be also supplied to the continental slope by the Antarctic Slope Current from the kaolin-rich metasedimentary rock outcropped on the Edward VII Peninsula.