• Title/Summary/Keyword: 다공성세라믹

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Removal Characteristics of Heavy Metals in Acid Mine Drainage (AMD) Using Porous Starfish Ceramics (II) - Treatment of AMD in a Column Reactor System (불가사리 소재 다공성 세라믹을 이용한 산성광산배수 내 중금속의 제거특성(II) - 컬럼연속 실험을 통한 산성광산배수의 처리특성)

  • Lee, Yonghwan;Yim, Soobin
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.12
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    • pp.25-34
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    • 2014
  • The objective of this study was to investigate the removal characteristics and the elimination mechanism of heavy metals in Acid Mine Drainage (AMD) using spherical-type porous Zeolite-StarFish ceramics (porous ZSF ceramics) packed in a continuous column reactor system. The average removal efficiencies of heavy metals in AMD were Al 98.7, As 98.7, Cd 96.0, Cu 89.1, Fe 99.5, Mn 94.4, Pb 96.3 and Zn 80.8 % during 110 days of operation time. The average removal capacity of porous ZSF ceramics for heavy metals were measured to be Al 21.76, As 1.52, Cd 1.27, Cu 3.41, Fe 44.83, Mn 3.48, Pb 2.36 and Zn $3.76mg/kg{\cdot}day$. The analysis results of mechanism using SEM, EDS and XRD exhibited that the porous ZSF ceramics could act as a multi-functional ceramics for the removal of heavy metals in AMD through the reactions of precipitation, adsorption and ion-exchange. The experimental results of column reactor system displayed that the porous ZSF ceramics would be a consistently efficient agent for the removal of heavy metals in AMD for a long term.

Fabrication of Porous Alumina Ceramics by Spark Plasma Sintering (방전 플라즈마 소결법에 의한 다공성 알루미나 세라믹스의 제조)

  • Shin, Hyun-Cheol;Cho, Won-Seung;Shin, Seung-Yong;Kim, Jun-Gyu
    • Journal of the Korean Ceramic Society
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    • v.39 no.12
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    • pp.1183-1189
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    • 2002
  • In order to develope the porous alumina ceramics with high strength, the pore characteristics and compressive strength were investigated in terms of relation to the conditions of spark-plasma sintering and the contents of graphite as a pore precursor. Porous alumina bodies were successfully prepared by spark-plasma sintering and burning out graphite in air. High porous bodies were fabricated by sintering at 1000${\circ}C$ for 3 min under a pressure of 30 MPa, heating rate of 80${\circ}C$/min and on-off pulse type of 12:2. For example, alumina bodies prepared by the addition of 10∼30 vol% graphite showed high porosity of 50∼57%. Also, the open porosity increased with graphite content. The relationship between pore characteristics and graphite contents could be explained by percolation model depending on cluster number and size. Porous alumina bodies prepared by the addition of 10∼30 vol% graphite showed the high compressive strength of 55∼200 MPa. This great improvement in strength was considered to be mainly due to the spark-plasma discharges and the self-heating action between particles.

A Study on Development of Porous SiC Ceramic Heat Sink from Solar Wafering Slurry (태양광 웨이퍼링 슬러리 재생 다공성 SiC 세라믹 히트싱크 개발에 관한 연구)

  • An, Il-Yong;Lee, Young-Lim
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.5
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    • pp.2002-2008
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    • 2012
  • In recent years, while the importance of thermal management has been emphasized due to smaller electronic products, various materials have been used as heat sink. In this study, porous ceramic heat sink was developed with SiC, successfully separated from the slurry of SiC occurring in solar energy materials industry and the thermal performance of porous SiC heat sink has been compared with those of aluminum heat sink and pure SiC heat sink through experiment. From the experimental results, it was verified that porous recycled SiC heat sink has better thermal performance than aluminum heat sink since its micropores increase the heat transfer area. In addition, the effect of the micropores on thermal performance has been quantified by increasing convective heat transfer coefficient with numerical analysis.

Analysis of Pore Characteristics on the Porous Body-Porosity Index of Ic and Is in Light Weight Aggregate (다공체 소지의 기공 특성 분석-경량골재에서의 기공지수 Ic와 Is에 대하여)

  • 권영진;이기강
    • Journal of the Korean Ceramic Society
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    • v.41 no.2
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    • pp.176-181
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    • 2004
  • EAF (Electric Arc Furnace) dust is classified as special wastes containing heavy metal contaminants may cause to damage an environment such as underground water contamination if they were not treated properly. For reutilizing the EAF dust, the porous body was made from EAF dust/clay composition system, and analyzed pore characteristics. It was found that a light-aggregate body was made up two different microstructures. One was non-black and dense microstructure which located near surface, and the other was black and porous microstructure (black coring) which located inner part. For systematizing the relationship of the black-coring area and the bloating degree, we defined the Ic(core index) and Is(shell index). It was found that the optimal bloating conditions of artificial light-weight aggregate were more than 0.5 of Ic and 0.4 of Is.

Process Development for Synthesis of Ultra-low Dielectric SiO2 Aerogel Thin by Freeze Drying (동결건조에 의한 극저유전성 실리카 에어로겔 박막 합성공정 개발)

  • 현상훈;김태영
    • Journal of the Korean Ceramic Society
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    • v.36 no.3
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    • pp.307-318
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    • 1999
  • 동결건조법에 의한 저유전성 실리카 박막의 제조공정 개발 및 층간 절연물질로의 응용성이 연구되었다. 코팅용 폴리머 실리카 졸은 TEOS와 이소프로판올(iso-propanol:IPA)또는 터트부탄올(tert-butanol:TBA)을 용매로한 2단계 공정에 의하여 제조되었으며, 이들 졸을 p-Si(111)웨이퍼 상에 스핀코팅한 습윤겔 박막을 동결건조 하여 다공성 실리카 박막을 제조하였다. 균일한 박막 코팅층을 얻을 수 있는 실리카 졸의 최적 점도범위는 IPA와 TBA를 용매로 한 실리카 졸의 경우 각각 10~14 cP와 20~30cP 정도였으며 스핀속도는 2000 rpm 이상이었다. 결함이 없는 다공성 실리카 박막은 TBA(빙점 $25^{\circ}C$)를 동결용매로 하여-196$^{\circ}C$까지 급랭시킨 후 $0^{\circ}C$와 0.1 torr 까지 가열 감압한 상태에서 고상의 TBAFMF 모두 제거한 다음 20$0^{\circ}C$까지 열처리하여 제조되었다. 다공성 실리카 박막의 두께는 졸의 타입과 스핀코팅 속도에 의해 2500~15000$\AA$범위 내에서 제어가 가능하였으며 이들 막의 밀도와 유전상 수 값은 각각 0.9$\pm$0.3g/㎤(기공율 60$\pm$10%)과 2.4 정도였다.

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