선탄 경석 재활용 원료를 이용한 유리 용융 특성

이지선,김선욱,라용호,이영진,임태영,황종희,전대우,김진호,Lee, Ji-Sun,Kim, Sun-Woog,Ra, Yong-Ho,Lee, Youngjin,Lim, Tae-Young,Hwang, Jonghee,Jeon, Dae-Woo,Kim, Jin-Ho 한국재료학회 2019 한국재료학회지 Vol.29 No.11

In this study, the glass melting properties are evaluated to examine the possibility of using refused coal ore as replacement for ceramic materials. To fabricate the glass, refused coal ore with calcium carbonate and sodium carbonate in it (which are added as supplementary materials) is put into an alumina crucible, melted at $1,200{\sim}1,500^{\circ}C$ for 1 hr, and then annealed at $600^{\circ}C$ for 2 hrs. We fabricate a black colored glass. The properties of the glass are measured by XRD (X-ray diffractometry) and TG-DTA (thermogravimetry-differential thermal analysis). Glass samples manufactured at more than $1,300^{\circ}C$ with more than 60 % of refused coal ore are found by XRD to be non-crystalline in nature. In the case of the glass sample with 40 % of refused coal ore, from the sample melted at $1,200^{\circ}C$, a sodium aluminum phosphate peak, a disodium calcium silicate peak, and an unknown peak are observed. On the other hand, in the sample melted at $1,300^{\circ}C$, only the sodium aluminum phosphate peak and unknown peak are observed. And, peak changes that affect crystallization of the glass according to melting temperature are found. Therefore, it is concluded that glass with refused coal ore has good melting conditions at more than $1,200^{\circ}C$ and so can be applied to the construction field for materials such as glass tile, foamed glass panels, etc.

ZnO가 포함된 BaO-GeO₂-La₂O₃ 계 광학 유리 특성

이지선,임태영,황종희,이영진,전대우,김선욱,라용호,김진호,Lee, Ji-Sun,Lim, Tae-Young,Hwang, Jonghee,Lee, Youngjin,Jeon, Dae-Woo,Kim, Sun-Woog,Ra, Yong-Ho,Kim, Jin-Ho 한국결정성장학회 2019 韓國結晶成長學會誌 Vol.29 No.5

$3{\sim}5{\mu}m$ 범위의 중적외선에서 75 % 이상의 투과율을 갖는 $BaO-GeO_2-La_2O_3-ZnO$ 계 유리를 제조 및 특성을 평가하였다. Flow button test를 통해 유리 용융이 가능한 조성을 선택 후, ZnO를 10 mol%, 20 mol% 각각 첨가하여 $1350^{\circ}C$에서 1시간 동안 용융하여 $BaO-GeO_2-La_2O_3-ZnO$ 계 유리를 제조하였다. 이 중에서 ZnO를 20 mol% 포함하는 16 mol% BaO-56 mol% $GeO_2-8mol%$ $La_2O_3-20mol%$ ZnO 계 유리 전이 온도 $660^{\circ}C$ 이하, 굴절률 1.70 이상, Knoop 경도 530 이상 값을 가지는 것을 확인하였다. 따라서, ZnO를 20 mol% 포함하는 $BaO-GeO_2-La_2O_3-ZnO$ 계 유리는 저온에서 양호한 용융 상태와 우수한 광학적 특성을 확인하였고 특수 광학용 재료 분야에 충분히 활용이 가능하리라 판단되었다. The glass of $BaO-GeO_2-La_2O_3-ZnO$ system with a transmittance of more than 75 % at mid-wave infrared (MWIR) region in the range of $3{\mu}m$ to $5{\mu}m$ is manufactured and its property is evaluated. After selecting construction that can melt glass through flow button test, $BaO-GeO_2-La_2O_3$ system where 10 mol%, 20 mol% of ZnO were added respectively were melted at $1350^{\circ}C$ for 1 hour and $BaO-GeO_2-La_2O_3$ system of glass was manufactured. Among them, with 20 mol% of ZnO, 16 mol% BaO-56 mol% $GeO_2-8mol%$ $La_2O_3-16mol%$ ZnO system of glass was found to has less than $660^{\circ}C$ of glass transition temperature, more than 1.70 of refractive index, and more than 530 of knoop hardness. Therefore, it is concluded that glass of $BaO-GeO_2-La_2O_3-ZnO$ system of glass with 20 mol% ZnO has good melting conditions at low temperatures and excellent optical properties, thus, can be utilized for special optical materials field.

슬래그 재활용 원료를 이용한 유리섬유 제조 및 특성

이지선,김선욱,라용호,임태영,이영진,전대우,김진호,Lee, Ji-Sun,Kim, Sun-Woog,Ra, Yong-Ho,Lim, Tae-Young,Lee, Youngjin,Jeon, Dae-Woo,Kim, Jin-Ho 한국재료학회 2018 한국재료학회지 Vol.28 No.12

In this study, glass fibers are fabricated via a continuous spinning process using manganese slag, steel slag, and silica stone. To fabricate the glass fibers, raw materials are put into an alumina crucible, melted at $1550^{\circ}C$ for 2 hrs, and then annealed at $600^{\circ}C$ for 2 hrs. We obtain a black colored glass. We identify the non-crystalline nature of the glass using an XRD(x-ray diffractometer) graph. An adaptable temperature for spinning of the bulk marble glass is characterized using a high temperature viscometer. Spinning is carried out using direct melting spinning equipment as a function of the fiberizing temperature in the range of $1109^{\circ}C$ to $1166^{\circ}C$, while the winder speed is in the range of 100rpm to 250rpm. We investigate the various properties of glass fibers. The average diameters of the glass fibers are measured by optical microscope and FE-SEM. The average diameter of the glass fibers is $73{\mu}m$ at 100rpm, $65{\mu}m$ at 150rpm, $55{\mu}m$ at 200rpm, and $45{\mu}m$ at 250rpm. The mechanical properties of the fibers are confirmed using a UTM(Universal materials testing machine). The average tensile strength of the glass fibers is 21MPa at 100rpm, 31MPa at 150rpm, 34MPa at 200rpm, and 45MPa at 250rpm.

Y₂O₃와 Fe₂O₃가 포함된 LAS 계 결정화 유리 특성

이지선,임태영,황종희,이영진,전대우,김선욱,라용호,김진호,Lee, Ji-Sun,Lim, Tae-Young,Hwang, Jonghee,Lee, Youngjin,Jeon, Dae-Woo,Kim, Sun-Woog,Ra, Yong-Ho,Kim, Jin-Ho 한국결정성장학회 2019 韓國結晶成長學會誌 Vol.29 No.4

용융 온도를 낮추고 균질화에 영향을 줄 수 있는 yttrium oxide(산화 이트륨)과 iron oxide(산화철)를 사용하여 $LI_2O-Al_2O_3-SiO_2$ 계 결정화 유리를 제조하였다. 조핵제는 Zirconium sulfate(황산지르코늄)을 사용했고, 유리 점도를 낮추기 위해 calcium phosphate(인산칼슘)을 사용해 유리 유동성을 원활하게 하였다. 결정화 유리는 열충격 $750^{\circ}C$ 이상을 만족했고, $800^{\circ}C$ 이상에서 열팽창계수가 급격하게 상승하는 온도를 약 $30^{\circ}C$ 이상 시프트 하였다. 따라서 yttrium oxide와 iron oxide 포함하는 LAS 계 유리는 고온에서 양호한 용융 상태와 우수한 열팽창 저항성을 확인하였고 특수 주방용 재료 분야에 충분히 활용이 가능하리라 판단되었다. The glass-ceramic of $Li_2O-Al_2O_3-SiO_2$ system was fabricated by using yttrium oxide and iron oxide that it can reduce the melting temperature and affect the homogenization. Zirconium sulfate was used as a nucleation agent. Calcium phosphate was used to improve the flow the glass so as reduce the viscosity of the glass. The glass-ceramics met a thermal shock test of more than $750^{\circ}C$ and the temperature at which the coefficient of thermal expansion rapidly increased at over $800^{\circ}C$ was shifted by about the above $30^{\circ}C$. Therefore, it is concluded that the glass-ceramic of $Li_2O-Al_2O_3-SiO_2$ system with yttrium oxide and iron oxide was founded to have good melting conditions and excellent thermal expansion resistance at high temperature such as special field for kitchen utensils.

붕소를 함유하지 않는 E-glass fiber의 제조 및 특성에 대한 연구

이지선,임태영,이요셉,이미재,황종희,김진호,현승균,Lee, Ji-Sun,Lim, Tae-Young,Lee, Yo-Sep,Lee, Mi-Jai,Hwang, Jonghee,Kim, Jin-Ho,Hyun, Soong-Keun 한국결정성장학회 2013 韓國結晶成長學會誌 Vol.23 No.1

E-glass 섬유는 항공기, 자동차, 레져기구의 복합재료 보강용으로 가장 널리 사용되는 유리섬유이다. 그러나 최근 E-glass 섬유의 원재료비 상승, 환경문제 및 화학적 저항성과 기계적 특성을 향상시키기 위해 산화붕소 함량을 8 %에서 0(제로)까지 감소시키는(소위 'Boron free E-glass'라고 불리는) 연구가 진행되고 있다. 본 연구에서는 'BF(Boron free E-glass)' 조성의 벌크유리와 섬유유리를 제조하고, 열적특성 및 광학적특성을 평가하였다. 5~10 %의 서로 다른 알루미나 함량을 갖는 배치를 $1550^{\circ}C$에서 2시간 용융하여 'BF(Boron free E-glass)'가 얻어졌고, 81~86 %의 높은 가시광투과율, $4.2{\sim}4.9{\times}10^{-6}/^{\circ}C$의 낮은 열팽창계수, $907{\sim}928^{\circ}C$의 연화점을 갖는 투명하고 맑은 유리가 얻어졌다. 'BF' 섬유 시편에 대한 화학적내구성 시험에 있어서는 알루미나 함량이 높아질수록 더 좋은 침식저항성을 나타냄을 확인할 수 있었다. E-glass fiber is the most widely used glass fiber for reinforced composite materials of aircrafts, automobiles and leisure equipments. But recently researches are being progressed to reduce boric oxide from 8 % to 0 (zero), as is called 'Boron free E-glass', because of increasing material cost, environmental problem, and improving chemical resistance and mechanical properties of E-glass fiber. In this study, we fabricated the bulk glass and fiber glass of 'Boron free E-glass (BF) compositions', and characterized thermal properties and optical properties. 'Boron free E-glass (BF)' was obtained by the melting of mixed batch materials at $1550^{\circ}C$ for 2 hrs with different $Al_2O_3$ compositions 5~10 %. We obtained transparent clear glass with high visible light transmittance value of 81~86 %, and low thermal expansion coefficient of $4.2{\sim}4.9{\times}10^{-6}/^{\circ}C$ and softening point of $907{\sim}928^{\circ}C$. For the chemical resistance test of 'BF' fiber samples, we identified that the higher alumina contents gives the better corrosion resistance of glass fiber.

섬유화 온도 변화에 따른 E-glass fiber의 물리적 특성

이지선,이미재,임태영,이영진,전대우,현승균,김진호,Lee, Ji-Sun,Lee, MiJai,Lim, Tae-Young,Lee, Youngjin,Jeon, Dae-Woo,Hyun, Soong-Keun,Kim, Jin-Ho 한국재료학회 2017 한국재료학회지 Vol.27 No.1

E (Electric) -glass fibers are the most widely used glass fibers, taking up 90 % of the long glass fiber market. However, very few papers have appeared on the physical characteristics of E-glass fibers and how they depend on the fiberizing temperature of fiber spinning. Glass fiber was fabricated via continuous spinning process using bulk E-glass. In order to fabricate the E-glass specimen, raw materials were put into a Pt crucible and melted at $1550^{\circ}C$ for 2hrs; mixture was then annealed at $621{\pm}10^{\circ}C$ for 2hrs. The transmittance and adaptable temperature for spinning of the bulk marble glass were characterized using a UV-visible spectrometer and a viscometer. Continuous spinning was carried out using direct melting spinning equipment as a function of the fiberizing temperature in the range of $1175{\sim}1250^{\circ}C$, while the winder speed was fixed at 500 rpm. Subsequently we investigated the physical properties of the E-glass fiber. The average diameter of the synthesized glass fiber was measured by optical microscope. The mechanical properties of the fiber were confirmed using a UTM (universal materials testing machine); the maximum tensile strength was measured and found to be $1843{\pm}449MPa$ at $1225^{\circ}C$.

유네스코 지속가능발전교육 공식프로젝트에 나타난 공간스케일의 유형

이지선,Lee Ji Sun 글로벌교육연구학회 2015 글로벌교육연구 Vol.7 No.2

유네스코 지속가능발전교육 공식프로젝트는 다른 조직이나 집단에 비해 지속성, 광범위성, 제도화 및 영향력을 지닌다. 2011년부터 2014년까지 총 51개의 유네 스코 지속가능발전교육 공식프로젝트를 분석한 결과 나타난 공간스케일 유형은 4개의 기본 스케일과 11개의 연계 스케일 유형이다. 공간스케일 유형의 빈도를 분 석한 결과는 다음과 같다. 첫째, 연계스케일 유형(69.6%)이 기본스케일 유형 (30.4%)에 비해 많이 나타난 것은 개별 공간스케일 중심 활동보다 여러 공간스케 일에서 활동이 이루어짐을 의미한다. 둘째, 기본스케일 유형 중 글로벌 스케일 (9.5%) 국지적, 지역적 스케일 유형(각각 7.6%), 인터내셔널 스케일(5.7%)이 나타난 것은 교육 내용이 공정무역, 빈곤감소, 평화, 인권 등 글로벌 수준에서 구성 되어있으며, 내 주변의 문제를 해결하고 지속가능한 지역개발을 위한 다양한 실천 프로그램을 실시함에 기인한다. 셋째, 연계스케일 유형 중 국지(지역)-글로벌 연 계 스케일이 36.3% 나타난 것은 지구공동체의 지속가능발전을 위한 교육을 지향 하는 유네스코 지속가능발전교육 공식프로젝트의 교육 내용이 글로벌 차원에서 계 획되었으며 지구공동체의 문제를 나의 문제로 인식하고 주변에서부터 실천하는 프 로그램으로 구성되어 있음을 알 수 있다. Korea UNESCO ESD Official Project sustainability compared to other official organizations and groups and has a wide range of gender, institutionalization and influence. 2011-2014 a total of 51 Korea UNESCO ESD Official Project presented the results of analyzing the spatial scale type of formal education projects are 4 basic types of scale and 11 connection types of scale. First, connection types of scale (69.6%) appeared more than basic types of scale (30.4%) refers to the activities in various space scales than the individual scale space center activities. Second, In basic types of scale the global scale (9.5%), local and regional scale type (7.6%), international scale (5.7%) appears this curriculum is composed in fair trade, poverty reduction, peace, human rights and global levels which is due in solving the problems around me, and carried out various action programs for sustainable regional development. Third, regional (local) - global connection types of scale of education represented 36.3% of the contents of Korea UNESCO ESD Official Project oriented education for sustainable development of the global community was planned at the global level in the global community. It is aware of the problem to my problems and found that contains the program to action from the surrounding.

정밀 지오이드 구축을 위한 자료처리의 최적 변수 결정

이지선,권재현,Lee, Ji-Sun,Kwon, Jay-Hyoun 한국공간정보학회 2009 한국공간정보학회지 Vol.17 No.3

기존의 우리나라 지상중력자료는 자료의 분포 및 정밀도에 있어서 문제점을 가지고 있었고 이러한 문제를 해결하기 위하여 2008년 항공중력측정을 통하여 정밀도 1.56mGal의 항공중력자료를 확보한 바 있다. 그러나 항공중력자료는 비행고도 상에서 획득된 값으로 기존의 지상중력자료 및 해상중력자료와 병합하기 위해서는 지표면 상의 값으로 환산되어야 한다. 또한 다양한 자료를 융합하여 정밀한 지오이드를 계산하기 위해서는 Stokes' 적분반경, Stokes' kernel 및 지형 효과 계산 반경 등의 많은 변수들을 최적으로 고려하여야 한다. 본 연구에서는 지상 및 항공중력자료의 분포 및 특성을 고려하여 보다 정밀한 지오이드 결정을 위한 최적의 매개변수들을 결정하고자 하였다. 선정된 최적 변수들을 적용하여 지오이드를 계산한 결과, 항공중력 및 지상중력 기반의 두 지오이드는 평균 -16.95cm, 표준편차 ${\pm}8.50cm$의 차이를 나타내었는데, 이는 지상 및 항공중력자료의 분포와 지상중력자료에 포함된 오차에 기인한 것으로 판단된다. 향후 본 연구에서 고려한 매개변수 외에도 다양한 하향연속 방법, 지형효과 계산 방법이 지오이드에 미치는 효과와 추가적으로 확보한 중력 및 GPS/Leveling 자료, 해상중력자료를 포함하였을 때의 효과에 대한 연구도 진행되어야 할 것이다. To solve the problems of distribution and quality on land gravity data, airborne gravity survey was performed in 2008 obtaining the airborne gravity data with accuracy of 1.56mGal. Since airborne gravity data is the obtained at the flight height, it is necessary to convert the airborne gravity data to the surface to combine various gravity data and compute precision geoid. In addition, Stokes' integral radius, Stokes' kernel and the radius of terrain effect computation should be optimally determined to calculate precision geoid. In this study, we made an effort to decide the optimal parameters based on the distribution and the characteristic of gravity data. Then, two geoid models were calculated using the selected parameters and the difference of geoid was calculated with mean of -16.95cm and the standard deviation of ${\pm}8.50cm$. We consider that this difference is due to the distribution and errors on the gravity data. For future work, the study on the effect of geoid with newly obtained land gravity data ship-borne gravity data and GPS/Leveling data should be conducted. Furthermore, the study on the downward continuation and terran effect calculation should be studied in detail for better precision geoid construction.

사암계 석탄폐석을 활용한 E-glass fiber 조성의 유리 제조 및 특성

이지선,임태영,이미재,황종희,김진호,현승균,Lee, Ji-Sun,Lim, Tae-Young,Lee, Mi-Jai,Hwang, Jonghee,Kim, Jin-Ho,Hyun, Soong-Keun 한국결정성장학회 2013 韓國結晶成長學會誌 Vol.23 No.4

삼척도계지역의 탄광에서 석탄채굴시에 부산물로 발생되는 사암계 석탄폐석을 원료로 사용하여 E-glass fiber 조성의 유리를 제조하였다. 본 연구에서는 카본함량이 비교적 적은 실리카-알루미나질의 사암계 석탄폐석을 사용하였으며, 폐석의 투입량을 0~35 %까지 변화시켰다. 서로 다른 석탄폐석 투입량을 갖는 배치원료를 $1550^{\circ}C$에서 2시간 용융하여 E-glass조성을 갖는 투명하고 맑은 유리가 얻어졌고, 81~84 %의 높은 가시광투과율, $5.39{\sim}5.61{\times}10^{-6}/^{\circ}C$의 열팽창계수, 851~$860^{\circ}C$의 연화점을 나타내었다. 유리섬유 시편은 $1150^{\circ}C$에서 섬유인상장치를 통해 얻어졌고, 복합재료의 보강용 유리섬유로서 내화학성 시험과 기계적 특성평가를 위한 인장강도를 측정하였다. 그 결과 석탄폐석을 사용한 E-glass fiber의 특성이 석탄폐석을 사용하지 않은 보통 E-glass 섬유에 비해 충분히 양호한 특성을 나타내어 E-glass 섬유용 원료로서 석탄폐석의 활용가능성을 확인할 수 있었다. The glass of E-glass fiber composition was fabricated by using refused coal ore which is obtained as by-product from Dogye coal mine in Samcheok. We used silica-alumina refused coal ore which has low carbon content relatively, and the amount of refused coal ore has been changed from 0 to 35 % in batch composition. E-glass was fabricated by the melting of mixed batch materials at $1550^{\circ}C$ for 2 hrs with different refused coal ore composition of 0~35 %. We obtained a transparent and clear glass with high visible light transmittance value of 81~84%, thermal expansion coefficient of $5.39{\sim}5.61{\times}10^{-6}/^{\circ}C$ and softening point of $851{\sim}860^{\circ}C$. The glass fiber samples were also obtained through fiberizing equipment at $1150^{\circ}C$, and tested chemical resistance and tensile strength to evaluate the mechanical property as a reinforced glass fiber of composite material. As the result, we identified the properties of E-glass fiber by using refused coal ore are plenty good enough compare to that of normal E-glass without refused coal ore, and confirmed the possibility of refused coal ore as for the raw material of E-glass fiber.

LBL법에 의해 TiO₂막이 코팅된 광촉매 글라스 비드 제조

이지선,채유진,이미재,김세기,황종희,임태영,현승균,김진호,Lee, Ji-Sun,Chae, Yoo-Jin,Lee, Mi-Jai,Kim, Sei-Ki,Hwang, Jong-Hee,Lim, Tae-Young,Hyun, Soong-Keun,Kim, Jin-Ho 한국재료학회 2012 한국재료학회지 Vol.22 No.7

$TiO_2$ thin films consisting of positively charged poly(diallyldimethylammonium chloride)(PDDA) and negatively charged titanium(IV) bis(ammonium lactato) dihydroxide(TALH) were successfully fabricated on glass beads by a layer-by-layer(LBL) self-assembly method. The glass beads used here showed a positive charge in an acid range and negative charge in an alkaline range. The glass beads coated with the coating sequence of(PDDA/TALH)n showed a change in the surface morphology as a function of the number of bilayers. When the number of bilayers(n) of the(PDDA/TALH) thin film was 20, Ti element was observed on the surface of the coated glass beads. The thin films coated onto the glass beads had a main peak of the (101) crystal face and were highly crystallized with XRD diffraction peaks of anatase-type $TiO_2$ according to an XRD analysis. In addition, the $TiO_2$ thin films showed photocatalytic properties such that they could decompose a methyl orange solution under illumination with UV light. As the number of bilayers of the(PDDA/TALH) thin film increased, the photocatalytic property of the $TiO_2$-coated glass beads increased with the increase in the thin film thickness. The surface morphologies and optical properties of glass beads coated with $TiO_2$ thin films with different coating numbers were measured by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD) and by UV-Vis spectrophotometry(UV-vis).