• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.99-105
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• 2010

This paper investigated the characteristics of wasteform containing a spent zeolite used as a separating agent of FPs for recycling LiCl waste which would be generated from pyrochemical process of spent PWR fuel. In this study, a conventional borosilicate and Ca-rich glass were used as a consolidating agent for spent zeolite and it's mixing ratio was changed in the range, $25{\sim}35wt%$. The leach rates of Cs and Sr had about $0.1{\sim}0.01g/m^2day$ and $0.001{\sim}0.0001g/m^2day$, respectively. The leach resistance of Cs increased with amount of SAP and it showed about 10 times higher in the Ca-rich glass wasteform than in the conventional borosilciate glass wasteform. The compressive strength of wasteform was affected with the amount of glass. Thermal expansion rate of containing 30wt% glass has relatively lower than others. Also, the melting temperature was little changed in given mixing ratio of glass.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3990-3996
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• 2014

Because the physical properties can be decreased when a Nylon 66/glass fiber composite is injected into a mold over $300^{\circ}C$, a systematic study of the thermal history in the case of re-use is needed. Nylon 66/glass fiber extrudates as a function of the extrusion number were prepared using a twin screw extruder at 305/290/273/268/265/$260^{\circ}C$. The chemical structure, thermal properties, melt index, crystal structure, Izod impact strength, and rheological properties were measured by Fourier transform infra-red (FT-IR), melt indexer, DSC, TGA, XRD, Izod impact tester, and dynamic rheometer. The FT-IR spectra indicated that the number of extrusions did not affect the chemical structure. The decrease in molecular weight with increasing extrusion number was confirmed by the melt index and the complex viscosity of extrudates. Based on the DSC and TGA results, the thermal history had no effect on the melting temperature, regardless of the number of extrusions, but the degradation temperature decreased up to $20^{\circ}C$ with increasing extrusion number. The Izod impact strengths of the extrudates were found to decrease with increasing extrusion number. No structural change after extrusion was also confirmed because there was no change in the slope and shape of the G'-G" plot.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1028-1034
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• 2002

Spinel/zirconia-glass composites prepared by melt-infiltration were fabricated to investigate the effect of zirconia addition on mechanical and optical properties of the composites. The infiltration distance was parabolic with respect to time as described by the Washburn equation and the penetration rate constant, K, decreased due to the reduction in pore size as the amount of zirconia rose. Although the optimum strength(308 MPa) of the Spinel/zirconia-glass composites was observed when the zirconia was added up to 20 wt%, K and transmittance decreased as the zirconia content rose. In conclusion, it suggested that the positive effect of strength as a result of the addition of zirconia was not effective.

• Korean Journal of Crystallography
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• v.17 no.2
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• pp.66-85
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• 2006

수열법으로 압전수정, 방해석 및 산화아연 단결정을 성장하고 각종 결함 및 성장된 단결정의 구조적, 화학적, 물리적 특성을 고찰하였다. 수열법은 직접 용융법으로 단결정을 성장할 수 없는 재료의 결정 성장에 많이 이용되며 수정의 경우, 융액의 점도가 매우 높고 유리화하는 성질이 있어 직접 용융으로 단결정을 성장할 수 없다. 방해석과 산화아연의 경우 용융하였을 때 분해되기 때문에 직접 용융법으로 단결정을 성장할 수 없어 수열법이 사용된다. 본 고찰에서는 수열법의 성장 원리와 성장 방법, 결함 검출 방법 및 물리적, 화학적 특성 측정 등을 다루었으며 또한 산업화 적용에 대하여 다루었다.

• Fire Science and Engineering
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• v.22 no.5
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• pp.22-28
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• 2008

In this paper, we conducted experiments on damaged patterns of incandescent lamps by external stress, such as external flame or external impact. Glass bulbs were melted and filaments were evaporated by external flame when the bulbs were lit, and finally molten marks were recognized at the filaments. Also, there were some differences in absorption patterns of evaporated filament elements according to set-up directions, and evaporated filament elements were absorbed in lead-in wires, support, inside of glass. In case the bulbs were lit and they were damaged by external impacts, filament burned out. Filaments were not evaporated but melted. We expect that this results could be used to judge whether electric current flew through incandescent lamps or not in fire site.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.367-372
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• 1996

석탄화력발전소의 산업부산물인 fly ash를 이용한 폐흡착재의 붕규산유리고화가 능성을 분석하였다. 폐흡착재는 기체상의 세슘이나 루테늄 등을 포집한 후에 발생되는 필터류 등의 고체폐기물을 말하며 본 실험에서는 CsNO$_3$와 fly ash를 몰비로 1.5 : 1 되게 섞어 1200 $^{\circ}C$에서 1시간 가소 시킨 후에 생성되는 pollucite를 모의폐흡 착재로 사용하였다. 폐흡착재를 무게비 15 ~ 30 %로 fly ash, SiO$_2$, $Na_2$CO$_3$, B$_2$O$_3$와 혼합한 후 1150 $^{\circ}C$에서 3시간 용융시켜 붕규산유리화시켰다. 제조된 붕규산유리고화체의 침출성을 평가하기 위하여 2일동안의 soxhlet 침출실험을 수행하였다. 한편 폐흡착재의 붕규산유리고화과정을 알아보기 위하여 붕규산유리고화체의 원료물질에 대하여 유리화과정과 동일한 조건하에서 TG/DTA분석을 수행하였다.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.191-194
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• 2002

본 연구는 친환경재료로서 생체, 전자, 환경재료로서 관심이 증가하고 있는 인산염계 저융점 유리의 열적특성 및 결정화에 대한 연구를 진행하였다. $K_2$O-CaO-P$_2$O$_{5}$ 삼성분계 인산염 유리에 대해 P$_2$O$_{5}$ 함량이 40~60mo1% 범위의 조성을 선정하여 전통 용융법에 의해 제조하였으며, 제조된 유리의 전자 패키징 및 저온소결 첨가제용 frit으로의 적용 가능성을 평가하기 위한 기초 연구로서, DSC, TMA를 통해 열적특성을 평가하였다. 제조된 유리의 연화온도는 320-5$50^{\circ}C$였으며, 열팽창 계수는 26~60$\times$$10^{-6}$/$^{\circ}C$의 범위였다. 제조된 유리의 열분석 결과로부터 최적 결정화 온도를 조사하였으며, 결정화 유리를 제조하여 XRD을 통해 결정상을 조사하였다.

• The Journal of Engineering Research
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• v.3 no.1
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• pp.199-205
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• 1998

Cullet Quality Control in auto glass bottle factory is the most important in recent days because of the increasing cost of materials in glass bottle. Since the composition of plate glass cullet is similar, the cullet quality using plate cullet in glass bottle factory is easily controlled. In addition to this, the price of plate glass cullet is so low that the cost reduction can be achieved. If the ratio of plate glass cullet and gush is over 25%, the liquidity of glass water become worse, which is caused by different compositions and viscosity of the components. As a results, Furnace bottom temperature becomes low and glass water becomes inhomogeneous. Thus production efficiency of glass bottle becomes low because of increasing devitrification in Dead Corner part in glass melting furnace. Three experimental methods – (1) increasing melting temperature, (2) using Booster, (3) using bubbler – were performed to increase the furnace bottom temperature and glass water homogeneity. The amounts of plate glass cullet was able to increase up to 90%, 70% and 60% without any devitrification using booster, bubbler and the method of glass melting temperature increase from $1480^{\circ}C$ to $1560^{\circ}C$ respectively. It is not possible to increase the glass melting temperature without the reduction of furnace operation time and the increase of fuel cost. The booster process has disadvantage of much electric energy consumption. Since the bubbler process uses physical convection of melting glass based on compression air, the homogeneity of molten glass is not so good as that of booster process but it can reduce the cost of glass bottle.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.2
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• pp.169-178
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• 2016

The properties of wastes for melting need to be considered to minimize the maintenance of refractory and to discharge the molten slags smoothly from a plasma torch melter. When the nonflammable wastes from nuclear facilities such as concrete debris, glass, sand, etc., are melted, they become acid slags with low basicity since the chemical composition has much more acid oxides than basic oxides. A molten slag does not have good characteristics of discharge and is mainly responsible for the refractory erosion due to its low liquidity. In case of a stationary plasma torch melter with a slant tapping port on the wall, a fixed amount of molten slags remains inside of tapping hole as well as the melter inside after tapping out. Nonmetallic slags keep the temperature higher than melting point of metal because metallic slags located on the bottom of melter by specific gravity difference are simultaneously melted when dual mode plasma torch operates in transferred mode. In order to minimize the refractory erosion, the compatible refractories are selected considering the temperature inside the melter and the melting behavior of slags whether to contact or noncontact with molten slags. An acidic refractory shall not be installed in adjacent to a basic refractory for the resistibility against corrosion.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.318-318
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• 1999