• Title/Summary/Keyword: Korean Chrysotile

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Consideration for the Highest Temperature Point Movement of the Dongrae Thermal Water in the Pusan Area. (Poster)

  • Kim Tong-Kwon;Lee Jin-Soo;Lee Seung-Gu;Song Yoon-Ho;Kim Tack-Hyun
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.10a
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    • pp.158-159
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    • 2005
  • This study showed that the highest temperature point of the Dongrae thermal spring in Pusan was moved to the north direction of the Dongrae fault as times goes by. The Br concentration(1.5mg/L) in Dongrae thermal waters indicated the influence of 2% seawater mixing. If the simple mixing without hydrochemical reaction occurs between seawater and thermal water, the concentration of Mg will be about 20mg/L. But the low concentration(0.1 mg/L) of Mg, contrary to high concentration(10 mg/L) of surrounding groundwater not affected by thermal water, suggested the thermal water, seawater and rock interactions. The calculation of saturation index(SI) by using the geochemical code of EQ3NR showed that the Mg in thermal groundwater, which was introduced by seawater, was removed by the precipitation of Antigorite (SI: log Q/K =71.753, $Mg_{48}Si_{24}O_{85}(OH)_{62}$) and Tremolite (SI: 8.463, $Ca_2Mg_5Si_8O_{22}(OH)_2$), Talc (SI: 6.409, $Mg_3Si_4O_{10}(OH)_2$), Dolomite (SI: 2.014, $CaMg(CO_3)_2$), Chrysotile (SI: 3.698, $Mg_3Si_2O_5(OH)_4$) in the crack of fault zone. The highest temperature point in the study area will move to north direction and stop in the Jangjun area without the input of seawater.

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Development of Source Profiles for Asbestos and Non-asbestos Fibers by SEM/EDX (SEM/EDX를 이용한 석면 및 비석명의 오염원분류표 개발)

  • Choi, Young-A;Lee, Tae-Jung;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.6
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    • pp.718-726
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    • 2007
  • There are many varieties of asbestos: chrysotile, crocidolite, amosite, tremolite, actinolite, and anthophylite. These are widely used in construction materials, brake lining, textile, and so on. Even though non-asbestos fibers such as glassfiber and rockwool have manufactured because asbestos causes asbestosis, lung cancer, mesothelioma, etc., some bad effects of non-asbestos have been also reported. PCM (phase contrast microscopy) and PLM (polarized light microscopy) have been used to qualitatively analyze asbestoses. These techniques have serious drawbacks when identifying and separating various asbestoses. Recently scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX) has been known as an useful tool to analyze airborne particle since it provides physical and chemical information simultaneously. The purpose of the study was to classify both asbestos and non-asbestos fibers and finally to develop their source profiles by using the SEM/EDX. The source profiles characterized by 6 different types of asbestos fibers and 2 types of non-asbestos fibers had been developed by analyzing a total of 380 fibers. Analytical parameters used in this study were length, width, aspect ratio, and shape as physical information, and Na, Mg, Al, Si, K, Ca, Cr, Mn, Fe, and Cu as chemical information. All the parameters were intensively reviewed.

A study on the status of asbestos use on ships (선박에서의 석면 사용실태 연구)

  • Park, Seung-Hyun;Chung, Eun-Kyo;Kwon, Ji-Woon;Kim, Kab-Bae;Chung, Kwang-Jae;Yi, Gwang-Yong;Shin, Jung-Ah;Lee, In-Seop;Kang, Seong-Kyu
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.21 no.3
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    • pp.123-127
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    • 2011
  • Objectives: The purpose of this study was to investigate the status of asbestos-containing materials (ACMs) used on ships and to consider measures for preventing worker exposure to asbestos fibers. Methods: A total of 17 ships including 16 ships under repair and a ship under construction at shipyards in Korea were investigated. Bulk samples were collected from suspected ACMs on engine exhaust pipes, boiler steam pipes, generator exhaust pipes, and etc. in ships in order to identify the presence of ACMs. Types and contents of asbestos were determined using polarized light microscopy (PLM). Results: ACMs were found from 14 ships out of 17 ships investigated. Only chrysotile asbestos was found from all samples. ACMs were mainly found from samples collected at the exhaust pipes of the engine, generator and incinerator, and boiler steam pipes where exhaust gases or steam of high temperature pass through. In most cases, types of ACMs were asbestos-containing fabrics such as asbestos tape. Friable ACMs were also found in some cases. Use of ACMs on ships was relevant to built time and owner of the ships rather than type and tonnage of the ships. Conclusions: ACMs were found from most ships built prior to 2000s. Therefore, measures for preventing asbestos-related diseases such as preparation of asbestos map on the ship and installation of warning signs, hazard communication with workers (ship-repairing workers, engine room workers and etc.), and follow-up for worker's health management are needed.

Classifying and Identifying Asbestos and Non-Asbestos Fibers by a Rule Building Expert System (전문가시스템을 이용한 석면 및 비석면의 분류 및 확인)

  • Choi, Young-A;Lee, Tae-Jung;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.3
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    • pp.346-356
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    • 2008
  • Asbestos is the name of a group of minerals with long and thin fibers that originate naturally in the environment. Asbestos mainly affects lungs and the membrane that surrounds the lungs. In general, PCM (phase contrast microscopy) and PLM (polarized light microscopy) have been used to analyze asbestos fibers. However, these methods have often problems to over-estimate number concentration when counting real asbestos fibers. Moreover, there are many difficulties when separating and identifying various asbestos and non-asbestos fibers. In order to determine quantitative information on fibrous particles, source profiles for asbestos and non-asbestos fibers must be initially developed on the basis of their chemical compositions and physical parameters. In our study, a SEM/EDX was used to develop source profiles from known asbestos samples as reference samples. We could make the source profile matrix consisting of 6 types of asbestos fibers and 2 types of non-asbestos fibers by analyzing 380 fibers. Based on these profiles, a rule building expert system was developed by using the visual basic application (VBA). Various fibers were successfully classified by 2 simple rules in the EXCEL environment based on several visual steps such as inserting data, viewing results, and saving results. For a case study to test the expert system, samples from a construction materials and from various indoor environments such as a residental area, a preschool classroom, and an underground store were collected and analyzed. As a result of the survey, a total of 76 individual test fiber particles was well classified into 5 different types of particle classes; 9.3% of chrysotile, 15.4% of amosite, 0.8 of crocidolite, 4.2% of tremolite, 5.8% glass fiber, 21.1% of other fibers, and 43.5% of unknown fibers in terms of number concentration. Even though unknown portion was high, it will be decreased markedly when expanding fiber source profiles.

A study on the quantitation of asbestos by the visual estimation and point counting method (시야평가법과 포인트계수법에 의한 석면정량평가 연구)

  • Choi, Yun-Ho;Kim, Tae-Hwa;Bae, Yong-Soo;Kim, Tae-Hyun;Kim, Hyeon-Ja;Jang, Eun-Ah;Hwang, Beom-Goo
    • Analytical Science and Technology
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    • v.27 no.3
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    • pp.153-160
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    • 2014
  • While variety of cases of studies about asbestos analysis methods are released internationally, the results of Asbestos Containing Materials (ACM) according to differences in the method of the analysis is becoming an issue. In this study, homogeneity ensured ACM samples were analyzed by visual estimation method and point counting method, and the result cound be used not only to improve the reliability on asbestos analysis of the institutions and analysts but also to obtain the basic data of Polarizing Light Microscope (PLM) analysis by comparing and evaluating. Asbestos analysis were divided into qualitative and quantitative analysis method. The quantitative analysis was performed by visual estimation method and point counting method (total 400 points) of EPA 600-R-93-116 method by using PLM. Firstly, The following was the result of homogeneity of the samples by ANOVA (Analysis of variance) and the results were satisfied. The results of qualitative analysis showed that the samples were chrysotile and amosite, and about the results of quantitative analysis, asbestos concentration determined by point counting method tend to be lower than concentrations determined by visual estimation method and also, pont counting method was a little more complicated and time-consuming.

The Production, the Use, the Number of Workers and Exposure Level of Asbestos in Korea (우리나라의 석면 생산과 사용 및 근로자 수와 노출농도의 변화)

  • Choi, Jung Keun;Paek, Do Myung;Paik, Nam Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.8 no.2
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    • pp.242-253
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    • 1998
  • South Korea has been producing asbestos over 60 years. The use of asbestos was over 50 years for production of asbestos slate and 27 years for asbestos friction materials including asbestos textile and brake-lining. Thus, it can be supposed that asbestos related diseases such as asbestosis, lung cancer and mesothelioma could be found in the vulnerable workers exposed to asbestos in 1955-1975, given the average latency period of 10-30 years. Asbestos was produced primarily by Japanese during World War II In Korea. The production of chrysotile peaked to 4,815 tons in 1944. From 1978 to 1984, 10,000 tons of asbestos were produced annually. However, the production was interrupted by raising labor costs and extinction of mine reserves, and finally they had to depend on import for the need of asbestos. In 1945, there were 16 asbestos mines, in total, with the addition of new asbestos mines in South Korea. Imports of asbestos was increased from 74,000 tons to 95,000 tons during the period of 1976 - 1992. But the imports was reduced to 88,000 tons in 1995. Since, in addition to the import of asbestos itself, the imports of asbestos products were increased as well and the accumulation of asbestos reached to 30,000 tons during the period of 1964 to 1993. In 1965, there was only one asbestos company with 207 employees. But the size of asbestos industry has been expanded so much that 118 asbestos companies could be found in 1993 with 1,476 workers. However, there was no record on the survey of asbestos concentration to which workers were exposed in any companies in 1983. The record of the air-borne concentration of the asbestos in textile working places in 1984 showed 6.7 fibers/cc by geometric mean(GM), but it was reduced to 1.2 fibers/cc in 1993. GMs of asbestos in working places for construction materials and asbestos textiles were also decreased from 1.7 fibers/cc to 0.55 fibers/cc during the period of 1984 - 1996.

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Origin of B, Br and Sr in Groundwater from Bukahn-myeon, Yeongcheon, Gyeongbuk Province, with Emphasis on Hydrochemistry (지하수의 수질화학적 특징과 붕소, 브롬, 스트론튬 성인에 대한 고찰)

  • Choo, Chang-Oh;Lee, Jin-Kook;Lee, Chang-Joo;Park, Ki-Ho;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.19 no.2
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    • pp.235-250
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    • 2009
  • Environmental elements such as B, Br, and Sr in groundwater from Bukahn-myeon, Yeongcheon, Gyeongbuk Province, were investigated in order to know their origin with emphasis on hydrochemistry. pH ranges from 7.37 to 8.39. B content is 0.41${\sim}$4.62 mg/L with an average 1.74 mg/L and Br content is 0${\sim}$3.24 mg/L with an average 2.22 mg/L, and Sr content is 0.93${\sim}$8.64 mg/L with an average 2.76 mg/L. The water types plotted by the Piper diagram are different but mostly $Ca-HCO_3$. Some constituents contributing to EC are Na, $SO_4$, Cl with high determinative coefficients($R^2$) of 0.85, 0.70, 0.90, respectively. The coefficients($R^2$) of Cl to Na, K, $SO_4$ are 0.54, 0.68, 0.53, respectively. It should be noted that there are high cocfficients($R^2$) of B-Sr and $Sr-SO_4$ with 0.65, 0.64, respectively. The Cl/Br ratios are 5.21${\sim}$30.70 due to significant depletion of Cl. The $SO_4/Cl$ ratios are 1.32${\sim}$27.24 with an average of 5.92, ascribed to abundant introduction of $SO_4$ or significant depletion of Cl. Chemical speciation calculated shows that B exists mostly as $H_3BO_3$ with less $H_2BO^-_3$ and Br exists as only $Br^-$. Sr exists mostly as $Sr^2$ with less $SO_4$. Saturation index represents that goundwater is supersaturated with respect to barite, kaolinite, illite, K-mica, and smectite while it is slightly undersaturated with respect to silica, gypsum, anhydrite, talc, chrysotile, feldspar, kaolinite, illite, K-mica, and smectite. The saturation index of celestine is -2.23${\sim}$-0.13 indicating more Sr can be incorporated into groundwater. Groundwater is still much undersaturated to halite. It is likely that the origin of S and Sr was related to the Yucheon volcanic rocks. Br might be originated from the local geological features with introduction of anthropogenic matters.

Inactivation of Asbestos-Containing Slate Using High-Temperature Plasma Reactor (플라즈마 고온반응기를 이용한 폐슬레이트 비활성화 연구)

  • Yoon, Sungjun;Jeong, Hyeonyi;Park, Byungno;Kim, Yongun;Kim, Hyesu;Park, Jaebong;Son, Byungkoo;Kim, Taewook;Mun, Youngbum;Lee, Sundong;Lee, Jaeyun;Roh, Yul
    • Korean Journal of Mineralogy and Petrology
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    • v.33 no.4
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    • pp.407-417
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    • 2020
  • The capacity of the designated landfill site for asbestos-containing waste is approaching its limit because the amount of asbestos-containing slate is increasing every year. There is a need for a method that can safely and inexpensively treat asbestos-containing slate in large capacity and at the same time recycle it. A cement kiln can be an alternative for heat treatment of asbestos-containing slate. We intend to develop a pilot scale device that can simulate the high temperature environment of a cement kiln using a high temperature plasma reactor in this study. In addition, this reactor can be used to inactivate asbestos in the slate and to synthesize one of the minerals of cement, to confirm the possibility of recycling as a cement raw material. The high-temperature plasma reactor as a pilot scale experimental apparatus was manufactured by downsizing to 1/50 the size of an actual cement kiln. The experimental conditions for the deactivation test of the asbestos-containing slate are the same as the firing time of the cement kiln, increasing the temperature to 200-2,000℃ at 100℃ intervals for 20 minutes. XRD, PLM, and TEM-EDS analyses were used to characterize mineralogical characteristics of the slate before and after treatment. It was confirmed that chrysotile [Mg3Si2O5(OH)4] and calcite (CaCO3) in the slate was transformed into forsterite (Mg2SiO4) and calcium silicate (Ca2SiO4), a cement constituent mineral, at 1,500℃ or higher. Therefore, this study may be suggested the economically and safely inactivating large capacity asbestos-containing slate using a cement kiln and the inactivated slate via heat treatment can be recycled as a cement raw material.

Preliminary Study on the Genesis and Nickel Potential of Ultramafic Rocks in Chungnam Yugu area, South Korea (충남 유구지역 초염기성암의 성인과 니켈 잠재성에 대한 예비연구)

  • Ijeung Kim;Sang-Mo Koh;Otgon-Erdene Davaasuren;Gi Moon Ahn;Chul-Ho Heo;Bum Han Lee
    • Korean Journal of Mineralogy and Petrology
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    • v.36 no.4
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    • pp.323-336
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    • 2023
  • We investigated the nickel potential and genesis of ultramafic rocks in the Yugu area to secure nickel resources in South Korea. The Yugu ultramafic rocks, located in the southwest of the Gyeonggi Massif, are characterized by spinel peridotite and exhibit strong serpentinization along their boundaries. The serpentinization is observed as olivine transformed to antigorite and chrysotile, while pentlandite, the nickel sulfide mineral, altered into millerite and awaruite. Serpentine displays distinct foliation, aligning subparallel to the ultramafic rock boundaries and foliation of Yugu gneiss. This suggests that the uplift of ultramafic rocks resulted in hydrothermal infiltration likely sourced from the Yugu gneiss metamorphism. The Yugu ultramafic rocks are residues after 5~18% partial melting of abyssal peridotite. Enriched light rare earth elements and Eu imply secondary metasomatism. Geochemistry suggests a link between the formation of Yugu ultramafic rock and the Triassic collision of the North and South China continents. The nickel content is around 0.17~0.21%, mainly contained in olivine and serpentine. Hence, in addition to the mineral processing study on the sulfide minerals, focused studies on oxide minerals for enhanced nickel recovery within the Yugu ultramafic rock are strongly suggested.