• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.1-8
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• 2023

In this study, to reduce CO₂ emission in the cement manufacturing process, we evaluated the limestone that is used as a raw material for cement, substituted with steel slag by the various substituted levels. Based on the chemical composition of each raw materials including limestone, and blast furnace slow cooling slag, converter slag, and KR slag as an alternative raw material, we simulated the optimal cement raw mixture by the substitution levels of limestone. Test results indicated that the steel slags contain a certain level of CaO that can be used as alternative decarbonated raw materials, and it has enough to partially reduce the amount of limestonem. And we estimated the maximum usable levels of each raw material. In particular, it was confirmed that by using a mixture of these raw materials rather than using them one by one, the effect of reducing limestone was increased and CO₂ emission from the cement manufacturing process could be reduced.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.219-226
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• 2020

Over the last decades, great efforts have been devoted to reuse industrial wastes and by-products from various industries as supplementary cementitious materials in order to reduce carbon dioxide(CO₂) emission by reducing the use of Portland cement in construction. Oyster shell waste, originating from the fishery industry, is available in huge quantities in certain areas, and is generally discarded or landfilled. In this study, we aimed to reuse oyster shell as an alternative to limestone in limestone calcined clay cement(LC³). The oyster shell calcined clay cement(OC³) paste were produced and were characterized via X-ray diffraction, isothermal calorimetry, compressive strength tests, and thermogravimetry. The results revealed that OC³ pastes exhibited similar strength development and reactivities by pozzolanic reaction with LC³, which implies that oyster shell could be used as a substitute for limestone in LC³.

• Water for future
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• v.49 no.5
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• pp.34-42
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• 2016

• Korean Journal of Poultry Science
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• v.31 no.3
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• pp.177-185
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• 2004

This experiment was conducted to examine the dietary effects of local granular ark shell(GAS) replacing limestone on egg shell quality in aged hens. A total of 200 Hy-Line Brown layers of 54-weeks-old were allotted into four treatments with five replications each. They were fed control(limestone only) 1% GAS, 2% GAS and 3% GAS diets for 6 weeks. GAS was substituted for coarse-type limestone at 0, 1, 2 or 3% of diet on weight basis. Particle sizes of limestone and GAS were within the ranges of 2~4 mm in diameters. In vitro HCl solubility of GAS was significantly lower(6.27 vs. 7.90%) compared to that of limestone(p < 0.05). The dietary treatment did not affect feed intake and egg production rate of the birds. Egg shell strength and thickness tended to be improved for birds fed the diets containing higher levels of GAS. The average egg shell strength and thickness of 2 or 3% GAS groups were significantly greater than those of the control (P < 0.05). The Tibial ash content of birds from 3% GAS group increased significantly as compared to that of the control. Tibial breaking strength, however, was not affected by the dietary treatment. Serum Ca and P contents of the birds were also not different among the dietary treatments. In conclusion, locally prepared GAS can be used as a calcium source in aged layer diet.

• 대한치과교정학회:학술대회논문집
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• 1999.11a
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• pp.55.3-55.3
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• 1999

• The monthly packaging world
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• s.374
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• pp.36-43
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• 2024

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.118-121
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• 2002

항만시설의 기본재료로서 가장 널리 사용되고 있는 피복석 (Rock armor)의 경우 저렴하며, 구입이 용이하다는 장점 때문에 여러 시설물에 적용되어 왔다. 그러나 계속되는 개발로 인해 석재원도 그 한계에 도달했기 때문에 더 이상 저렴한 재료라고 할 수도 없으며, 무엇보다 난 개발로 인한 국토의 훼손과 이에 따른 비난의 여론으로 인해 피복석의 사용이 제한을 받고 있다. (중략)

• Journal of Conservation Science
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• v.27 no.2
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• pp.211-222
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• 2011

The Mireuksaji stone pagoda was built foundation in the reign of King Moo (AD 639) in the Baekje Kingdom of ancient Korea. The stone properties of the pagoda were quarried from Mountain Mireuk, which are medium to coarse-grained light gray biotite granite formed during the Jurassic, and are composed of quartz, feldspar, biotite, muscovite, apatite and allanite. It was strong relatively but became weak from prolonged weathering, and as a result its durability fell to $883kgf/cm^3$ (moderate weathering degree). In the process, cut-off (31%), deletion (57%) and crack (44%) occurred in foundation materials by the influence of bending, shear and compressive force. Hereat, the original materials were treated through a preservation process. As a result, approximately 74% of original materials have been able to be reused, inclusive of 55 materials that were to be partially replaced by new stones. On the other hand, it is inevitable that the other 26% including exterior stones and support-based stones have to be partially replaced by new stones. It implies that there is a need to find stones that are identical or similar to those of the pagoda. Consequently, a lithological study was conducted on stones in quarries located in Iksan and an investigation was made into their properties. The results showed that stones in the Hwangdeung area were most similar to those of the pagoda mineralogically and their properties were most stable.

• Ceramist
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• v.20 no.1
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• pp.103-118
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• 2017

1. 2014년도 우리나라 전체 폐기물 발생량은 146,607천 톤이며, 건설폐기물이 46.2%(67,644천 톤), 사업장 일반폐기물이 38.1%(55,914천 톤), 생활폐기물이 12.4%(18,219천 톤), 사업장 지정페기물이 3.3%(48,810천 톤)을 나타내고 있다. 2. 건설폐기물의 97.9%, 배출시설계 폐기물의 77.3%, 생활폐기물의 67.0%, 지정폐기물의 57.3%가 재활용되고 있다. 3. 2015년도 우리나라 시멘트산업에서 18,801천 톤의 순환자원을 재활용하였다. 폐기물이 6,136천 톤이고, 부산물이 12,665천 톤이다. 부산물은 11,000천톤이 제철슬래그이고, 1,600천 톤이 폐석고(탈황석고 중화석고)로 추정된다. 그리고 폐기물 6,136천 톤은 사업장 일반폐기물의 약 11.0%에 해당된다. 4. 시멘트 톤당 순환자원 사용량(재활용 원단위)은 일본이 400kg/톤 이상이고 우리나라는 300kg/톤 대를 나타내고 있다. 일본이 우리나라보다 재활용량/톤이 많은 이유를 다음에서 찾을 수 있다. (1) 고품위 석회석 원료 (2) 법 제도(지원금 포함) 5. 원료 대체율의 산출은 다음 두 산출방법으로 나타낼수 있다. (1) 이론적인 원료 상한 대체량에 대한 실제 원료 대체량 (2) 이론적인 원료 조합량에 대한 실제 원료 대체량 2015년도 우리날 전체 원료 대체량(17,770천 톤)은 (1)에 의한 대체율 : 71% (2)에 의한 대체율 : 27% 6. 자동차 슈레더 더스트(ASR)를 시멘트산업에서 자원화 하게끔 ASR처리의 보완 및 법적지원(지원금 포함)이 요망된다. 7. 부산물 및 폐기물의 자원화는 시멘트산업에서의 이용이 가장 우수한 장점을 갖추고 있다. 그러므로 시멘트산업에서 폐기물의 자원화를 적극 추진하게끔 제도의 보완 및 시설지원 등 정부의 대책수립이 간절하다.

• Cement Symposium
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• s.49
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• pp.27-28
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• 2022

The cement industry emits a large amount of CO₂, and 60~65% of the CO₂ is generated from calcination of raw materials. So, the CO₂ from cement industry can be reduced by substituting decarbonated materials for limestone. In this study, the chemical composition and grindability of three types of steel slag were evaluated and the application of those materials will be examined for the production of low heat portland cement.