Reaction Characteristics of the CAC with Various Gypsum Type and Mixing Ratio

Sun-Mi Choi; Jin-Man Kim; Ja-Sul Koo

doi:10.7844/kirr.2021.30.1.83

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Research Paper

Reaction Characteristics of the CAC with Various Gypsum Type and Mixing Ratio 석고 종류 및 혼입률에 따른 CAC 반응 특성

28 February 2021. pp. 83-91

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Abstract

Ladle furnace slag is a byproduct of the steel-making process, and it contains the mineral β-C₂Sandtherapid-settingmineral (dependingonwhichreducingagenthasbeenused). Ladle furnace slag is often treated through slow cooling, which causes the slag to lose its reactivity. In this study, the properties of air-quenched CAC and pulverized ladle furnace slag containing gypsum were evaluated, and the optimal mixing ratio was determined for broadening their usage. Consequently, the properties of CAC aredemonstrated by the dissolution of gypsum after a period of three hours and the content of gypsum after a period of one day. The optimal mixing ratio of anhydrate and hemihydrate gypsum is found to be within 30% and that of dihydrate gypsum is found to be higher than 35%. Furthermore, based on the results of CAC with dihydrate gypsum, the applicability of the by-product dihydrate gypsum has been verified.

Keywords

Ladle Furnace Slag

Slag Atomizing

Rapildy Cooled Slag

Ettringite

Gypsum

조강 생산 시 발생되는 슬래그는 대부분 서냉 방식에 의해 처리되고 있다. 하지만 슬래그 중 일부는 속경성 광물을 포함하고 있음에도 불구하고, 서냉 방식에 의해 그 반응성을 상실하게 된다. 이에 본 연구에서는 제강환원슬래그를 SAT공법에 의하여 공기 급냉하여 선별 및 분급 후 분쇄한 CAC의 활용성 확대를 목적으로 석고 종류 및 혼입율에 따른 CAC의 특성에 관하여 고찰하였다. 그 결과, CAC는 3시간에서는 석고 용해도, 1일 이후에는 석고 함량비에 따라 특성이 나타나는 것을 확인하였다. 반수, 무수석고의 적정 혼입율은 30% 이내, 이수석고는 35% 이상인 것을 확인하였으며, 이수석고의 혼입율 및 특성 확인을 통하여 부산이수석고의 적용 가능성을 확인하였다.

키워드

전기로 환원슬래그

슬래그 아토마이징

급냉 슬래그

에트린자이트

석고

References

Choi, S.M., Kim, J.M., 2013 : Hydration Properties according to the degree of crystallinity of CA Slag Cooled by High-Pressure Air, Proceeding of the International Symposium on green Manufacturing and Application, pp.25-29, The Korean Society for Precision Engineering, Hawaii, USA, 2013. 6.

Choi, S.M., Kim, J.M., 2013 : Evaluation of Vitrification Rate of CaO-Al₂O₃ Based Steel Slag according to Cooling Speed, Journal of Korea Concrete Institute, Proceeding paper, 25(1), pp.153-154.

Lee, K.J., Koo, J.S., Kim, J.M., et al., 2013 : Eexperimental Study on the Development of Applications for Rapidly Chilled CaO-Al₂O₃ Steel Slag, ISWA 2013 World Congress, pp.7-11.

Kim, J.M., Choi, S.M., Han, D.W., 2016 : Improving the mechanical properties of rapid air cooled ladle furnace slag powder by gypsum, Construction and Building Materials, 127, pp.93-101. 10.1016/j.conbuildmat.2016.09.102

Kong, T.W., 2005 : Enhanced durability performance of regulated set cement concrete, Master's Thesis of Konkuk University, Korea, pp.80-82.

Jang, B.K., Jung, C.J., Lee, J.H., et al., 1998 : Cement Material Chemistry, Publishing department of Chonnam National University, pp.74-76.

Kim, J.H., 2012 : Pore Structure of Ladle Furnace Slag Powder Paste with Gypsum, Journal of the Korean Recycled Construction Resources Institute, Proceeding paper, 12(2), pp.35-36.

Information

Publisher :The Korean Institute of Resources Recycling
Publisher(Ko) :한국자원리싸이클링학회
Journal Title :Resources Recycling
Journal Title(Ko) :자원리싸이클링
Volume : 30
No :1
Pages :83-91
Received Date : 2021-01-22
Revised Date : 2021-02-15
Accepted Date : 2021-02-16
DOI :https://doi.org/10.7844/kirr.2021.30.1.83

Resources Recycling ISSN:2765-3439(Print) 2765-3447(Online) 자원리싸이클링

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