A Fundamental Study on the Reduction of Iron in EAF Slag Using Waste MgO-C Refractory

Seung-Uk Hwang; Jei-Pil Wang

doi:10.7844/kirr.2025.34.1.14

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2025 Vol.34, Issue 1 Preview Page Next Page

Research Paper

A Fundamental Study on the Reduction of Iron in EAF Slag Using Waste MgO-C Refractory 폐 MgO-C계 내화물을 이용한 전기로 슬래그의 철 환원 기초연구

28 February 2025. pp. 14-20

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Abstract

This study aimed to determine the methods of employing waste MgO-C refractories as a flux to replace light-burned dolomite mainly used in the electric furnace during the steelmaking process. The slag used in this study was supplied by a domestic forging company, and its chemical composition was analyzed. Subsequently, a base slag was prepared by mixing it with FeO, SiO₂, and Al₂O₃. Next, the base slag was manufactured by mixing it with a flux at 1600℃. To compare the slag with added light-burned dolomite, quicklime, and waste MgO-C refractory and the slag containing only light-burned dolomite and quicklime, the analysis of XRD and XRF was performed. The basicity was within the appropriate range of 2 to 3 for the EAF slag containing MgO-C refractory, and metallic iron reduced from slag was found to have an iron content of 97.74 wt.%. By partially replacing light-burned dolomite with waste MgO-C refractory as a steelmaking reduction agent, it was observed that metallic iron recovery of over 50% from the slag was feasible due to the carbon component in the waste refractories.

Keywords

MgO-C refractory

Flux

EAF slag

light burned dolomite

본 연구는 전기로 제강 공정에서 주로 사용되는 경소돌로마이트를 폐 MgO-C계 내화물을 활용하여 Flux로서 재활용하고, 이를 통하여 슬래그 내 철을 환원하는 기초연구를 진행하였다. 연구에 사용된 슬래그는 국내 단조기업에서 EAF(Electric Arc Furnace) Slag를 공급받아 조성분석을 진행하였다. 이후 FeO, SiO₂, Al₂O₃를 혼합하여 base slag를 제조하였고 1600℃에서 Flux를 혼합하여 EAF slag를 제조하였다. 경소돌로마이트, 생석회와 폐 MgO-C 내화재를 추가한 슬래그와 경소돌로마이트, 생석회만을 Flux로 투입한 슬래그의 화학조성 및 상을 비교하기 위하여 XRD와 XRF 분석을 실시하였다. 염기도는 폐 MgO-C 내화물을 넣은 EAF slag가 2~3 범위로 적정 범위였으며, 슬래그로부터 환원된 철립은 분석결과 Fe함량 97.74%로 확인되었다. 경소돌로마이트 사용량 중 일부를 폐 MgO-C 내화물로 대체하여 제강 환원제로 재활용함으로서, 내화물 내의 탄소 성분으로 인하여 산화 슬래그로부터 제선용 철 품위(50% 이상)을 회수하는 것이 가능할 것으로 판단된다.

키워드

MgO-C 내화물

Flux

EAF slag

경소돌로마이트

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Information

Publisher :The Korean Institute of Resources Recycling
Publisher(Ko) :한국자원리싸이클링학회
Journal Title :Resources Recycling
Journal Title(Ko) :자원리싸이클링
Volume : 34
No :1
Pages :14-20
Received Date : 2024-11-15
Revised Date : 2024-12-19; 2025-01-21
Accepted Date : 2025-01-21
DOI :https://doi.org/10.7844/kirr.2025.34.1.14

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

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