Título

Modern Steelmaking Using AC and DC Electric Arc Furnaces and Secondary Steel Making

Autoria

MEGER, PETER

MEGER, PETER

Eu sou esse autor

DOI

10.5151/2594-5327-49v7-475-488

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Resumo

The major developments in electric steelmaking began at the start of the 1960s. Besides the use of more powerful transformers and the process of oxygen injection, several further developments like scrap preheating, oxy-fuel burners, ladle metallurgy, and slag-free tapping in EBT took place. These led to specific installed power of up to 1000 kVA/t of tapping weight and graphite electrode consumption around 2.0 kg/t of liquid steel. The direct current electric arc furnace (DC-EAF) for steel production has been booming for the past five years. In addition to small and medium-sized furnaces, even 150-ton tapping weight furnaces have been designed and commissioned. Mannesmann Demag commissioned its first DC-EAF at the Belgian company Usines Gustave Boel. This DC-EAF features water-cooled bottom electrodes with independent electrical circuits and specialized bus bar routing. High availability and productivity of both DC and 3-phase AC electric arc furnaces are achieved using twin-shell furnaces with a slewable electrode arm. Transformer capacity utilization can reach up to 92%, and tapping times of less than 40 minutes per shell place the arc furnace on par with converters, with liquid steel undergoing final treatment in the ladle furnace. All modern and newly designed electric melt shops are equipped with ladle furnaces. Even converter shops now adopt the benefits of ladle furnaces. The Demag Inert Gas Roof offers advantages such as lower operating costs and higher availability, and the mono-arm ladle furnace design shows benefits compared to conventional ladle furnaces.

Palavras-chave

Electric arc furnace, AC/DC, Twin-shell, Secondary metallurgy, Ladle furnace