• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.342-348
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• 2001

This study was conducted to obtain granular crystalline gypsum that can be used as raw material for plaster boards or cements from waste Plaster board. We could disintegrate preferentially gypsum to gypsum needle in 10${\mu}{\textrm}{m}$ or less size among the contents of waste plaster board (gypsum, paper, fiber, and inorganic material .etc.) by hydration afterwards the dehydration of crushed waste plaster board. In this case, the optimum conditions for minimizing the size of gypsum were dehydration rate of 75%~ 85%, hydration concentration of 10~20%, agitation speed of 250~400rpm, crushing size of 2cm or less. Gypsum of 98.21% grade was recovered with 99.0% yield from under screenings of 325mesh wet screening which followed by the dehydration-hydration process performed in the conditions of dehydration rate of 80%, hydration concentration of 15%, agitation speed of 300rpm, crushing size of 2cm or less. Subsequently, Plate-like Crystalline gypsum of is 151${\mu}{\textrm}{m}$ size and the grade of 99.49% with the Yield of 98.0% from the upper screenings of 270mesh wet screening carried out after the re-crystallization of the recovered gypsum needle slurry.

• 자원리싸이클링
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• 제10권6호
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• pp.43-52
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• 2001

This study was conducted to obtain granular crystalline gypsum that can be used as raw material for Plaster boards or cements from waste Plaster board. Gypsum could be Preferentially disintegrated to gypsum needle in $10\mu\textrm{m}$ or less size by hydration after the dehydration of crushed waste Plaster board. The finer the gypsum needle, it is easier to remove coarse impurities and to recover the gypsum needle. The optimum conditions for obtain the finer gypsum size were dehydration rate of 75~85%, solid concentration at hydration of 10~15%, agitation speed of 250~400 rpm, crushing size before dehydration of 2 cm or less. Gypsum of 98.21% grade was recovered with 99.0% yield as the undersize of 325 mesh wet screening followed by the dehydration-hydration process performed at the conditions of dehydration rate of 80%, solid concentration at hydration of 15%, agitation speed of 300 rpm, crushing size before dehydration of 2 cm or less. After the recrystallization of recovered gypsum, Plate-like gypsum of $151\mu\textrm{m}$ size with 99.49% grade was obtained as the oversize of 270 mesh in a wet screening.

• 자원리싸이클링
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• 제17권2호
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• pp.16-29
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• 2008

우리나라 사업장 폐기물의 51.7%에 해당되는 47,294천톤이 건설폐기물이고, 이 폐기물의 96.7%가 재활용되는 것으로 집계되어 있다. 한편 고품질 순환골재의 생산을 일부기업에서 시도하고 있으나, 천연골재를 대체하기에는 아직 미급한 것 같다. 우리나라의 경우 혼합폐기물의 정의가 애매하여, 혼합폐기물의 선별자원화가 매우 부실하다. 폐목재의 경우 PB(particle board)용으로 수요가 많으나, 현장에서 폐목재의 수집이 쉽지 않다. 2005년 대형국책과제를 수행하는 $\ulcorner$건설폐기물재활용연구단$\lrcorner$이 발족하였다. (사)한국자원리싸이클링 학회지에 게재된 건설폐기물 관련 보문은 주가 폐기물을 이용해서 건설자재로 재활용하는 것에 관한 것이었다.

• KIEAE Journal
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• 제7권1호
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• pp.33-40
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• 2007

0.4 Million tons of shell powder have been disused as waste in KOREA and caused severe environmental pollution though shell powder can be utilized in real life for many ways. It is impending problem to recycle shell powder as it requires high expense for burying and temporary outside heap and causes severe environmental pollution being a main factor of ocean waste. To suggest the basic data for development of eco-friendly and high-function Wall Coatings Thin Textured Finishes, a wall coating sample was applied to indoor walls of a mock-up and temperature and humidity were measured to assess the thermal performance of it, and a survey of preference for the color sense and feel of the materials with a movie of specimens. The results of the study are following; 1) High insulation performance is shown from the assessment result of the room polystyrene board adhered on the walls then high humidity controlling performance is shown from that of the room polystyrene board coated by shell powder. This point out that shell powder has superiority for humidity controlling. 2) The result of thermal and humidity assessment shows that shell powder makes up for thermal conduction of the polystyrene board and same result can be expected from the assessment with materials which has similar thermal characteristics with polystyrene.3) Ranking of preferred specimens is; 1st Case 13, 2nd Case 17, 3rd Case 16, and 4th Case 12. Preferred shell powder was the ark shell. Preferred powder for plaster was the powder mixed with that sifted by 0.8mm, 100mesh and 40mesh, and for spray was the fine powder mixed with that sifted by 100mesh and 40mesh.