The Study on the Separation of Steelmaking Slags Using Air Classification

Seolji Nam; Sungkoo Jo; Hoonha Lee

doi:10.7844/kirr.2024.33.5.51

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2024 Vol.33, Issue 5 Preview Page

Research Paper

The Study on the Separation of Steelmaking Slags Using Air Classification 공기분급을 이용한 제강슬래그 선별 연구

31 October 2024. pp. 51-57

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Abstract

The cement industry, one of the major greenhouse gas-emitting sectors in South Korea, produces approximately 39 million tons of greenhouse gases annually, with over half of this emission stemming from the calcination of limestone (CaCO₃). This study investigates the behavior of key components in slag generated by Company “P”, utilizing ball mill grinding technology and air classification technology to explore the effects of process condition changes. In particular, the study aims to understand the separation behavior of CaO and Fe within the slag through the application of air classification technology. The results indicate that as the rotor speed of the air classifier increases, the CaO content increases by up to 9.97%, while the Fe content decreases by up to 24.27%. Considering the recovery rate, it was determined that operating the rotor at a speed below 5,000 rpm is efficient. This study demonstrates the utility of air classification technology for utilizing slag, a byproduct of steelmaking, as an alternative raw material for cement calcination, confirming the potential to control the contents of CaO, Fe, and Cr in the slag.

Keywords

Steelmaking slag

Limestone

Greenhouse gas

Air classification

Non-carbonate

국내 온실가스 다배출 산업 중 하나로 손꼽히는 시멘트 산업은 연간 3,900만ton 가량의 온실가스를 배출하며, 이 중 절반 이상이 석회석(CaCO₃)이 하소되는 과정에서 기인한다. 이에 본 연구에서는 국내 P社에서 발생하는 전로슬래그를 대상으로 볼밀 분쇄 기술 및 공기 분급 기술을 적용하여 공정 조건 변경에 따른 주요 성분들의 선별 거동을 탐색하였으며, 특히 공기 분급 기술을 적용하여 슬래그 내부 비탄산염 성분인 CaO와 철질 원료인 Fe의 선별 거동을 파악하고자 하였다. 연구 결과 공기 분급기 로터의 회전속도가 증가함에 따라 CaO 함량이 최대 9.97% 증가, Fe 함량은 최대 24.27% 감소하였으며, 회수율을 고려하였을 때 로터의 회전 속도가 5,000rpm 이하가 되도록 작동하는 것이 효율적임을 도출하였다. 본 연구를 통해 제철공정 부산물인 슬래그를 활용하여 시멘트 소성용 대체 원료로 활용하기 위해 공기 분급 기술이 유용성을 입증하였으며, 슬래그 내부 CaO, Fe, Cr 함량을 제어 가능성을 확인하였다.

키워드

제강슬래그

석회석

온실가스

공기분급

비탄산염

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Information

Publisher :The Korean Institute of Resources Recycling
Publisher(Ko) :한국자원리싸이클링학회
Journal Title :Resources Recycling
Journal Title(Ko) :자원리싸이클링
Volume : 33
No :5
Pages :51-57
Received Date : 2024-09-19
Revised Date : 2024-10-10; 2024-10-17
Accepted Date : 2024-10-21
DOI :https://doi.org/10.7844/kirr.2024.33.5.51

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

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