Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
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Effect of Carbon Materials on the Slag Foaming in EAF Process

전기로 슬래그 포밍에 미치는 가탄재 종류의 영향

  • Kim, Young-Hwan (Steelmaking Research Team in R&D Center of Dongkuk Steel Mill Co.) ;
  • Yoo, Jung-Min (Steelmaking Research Team in R&D Center of Dongkuk Steel Mill Co.) ;
  • Um, Hyung-Sic (Steelmaking Research Team in R&D Center of Dongkuk Steel Mill Co.)
  • 김영환 (동국제강 중앙기술연구소 제강연구팀) ;
  • 유정민 (동국제강 중앙기술연구소 제강연구팀) ;
  • 엄형식 (동국제강 중앙기술연구소 제강연구팀)
  • Received : 2019.01.04
  • Accepted : 2019.02.21
  • Published : 2019.04.30
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Abstract

During steelmaking in EAF, recycled scraps is used as a main material, melted by arc, and electricity use as a main energy. Slag foaming is an important technology for reducing electrical energy. CO gas generated by the reaction between injection carbon and (FeO), [C] and injection {$O_2$}. CO gas generated by this reaction is collected in slag, resulted in slag foaming. In general, the carbon materials used in the EAF process is anthracite and coke. This study investigated the effects of the carbon materials used on slag foaming in the steelmaking process. As a result of this study, the slag foaming height is increased by cokes rather than anthracite, and with an increase in the amount of particles samller than $500{\mu}m$. Based on these results, the application to the operation resulted in increase of slag forming height, reduction of injection carbon, and reduction of electrical energy.

전기로 공정은 스크랩을 재활용하여 주원료로 사용하고 아크에 의해 용해하며, 전력을 주 에너지로 사용한다. 슬래그 포밍은 전력에너지 저감에 중요한 요소 기술이다. 투입되는 가탄재(분탄)와 슬래그 중 FeO와의 반응과 용강 중의 카본과 투입되는 산소와의 반응에 의해 CO가스가 발생된다. 이러한 반응에 의해 발생된 CO가스는 슬래그에 포집되어 슬래그 포밍 현상이 일어난다. 전기로 제강 공정에서 일반적으로 가탄재는 가공분탄(무연탄)과 cokes를 사용하고 있다. 본 연구는 전기로 제강 공정에 사용되는 가탄재에 따른 슬래그 포밍의 영향을 조사하였다. 연구 결과 가공분탄 보다는 cokes에 의해 슬래그 포밍 높이가 증가 되었으며, 입도 $500{\mu}m$ 이하의 입자 함량이 증가할수록 포밍높이가 증가하는 결과를 나타내었다. 이러한 결과를 바탕으로 조업에 적용한 결과, 슬래그 포밍높이 증가와 가탄재 원단위 저감, 전력에너지 저감의 효과를 얻었다.

Keywords

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Fig. 1. Experimental apparatus used for measurement of slag foaming height.

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Fig. 2. Foaming height change with FeO content in slag.

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Fig. 3. Foaming height change with injection carbon materials.

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Fig. 4. Size distribution of injection carbon.

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Fig. 5. Change of Foaming height after size control.

Table 1. Composition of EAF slag used in foaming height measurement with injection carbon

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Table 2. Composition of Injection carbon

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Table 3. Comparison of EAF operation indics with injectioncarbon

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