The Benefits of Lime Injection in the Electric Arc Furnace

Historically, steelmakers have experimented with various methods for adding lime to the EAF including scrap bucket discharge, fifth-hole addition through the roof, super sack drops and lime screening and briquetting.

However, many of these techniques created significant environmental issues with lime emissions in the shop. Even with some improvement in reducing lime emissions using the fifth-hole through the roof, lime fines were still generated through the various drop points and transferred to the baghouse through the furnace evacuation system. The impact from these mechanical systems could be seen in lime yield being lost to the baghouse and in the shop environment.

The emergence of the foamy slag practice to protect the furnace sidewall and refractory created a need to efficiently introduce lime during the melting process. It is highly desirable that lime is added to the process at the right time and in the right position within the furnace. Early attempts at sidewall lime injection were made in the early 1990s. Since then, advances have been made in areas of equipment design, slag practice and lime quality. 

Lime injection now provides a reliable technology for steelmakers to control foamy slag, reduce waste disposal, improve safety and save electrical energy.