Steel Foundry Refractory Lining Optimization: Electric Arc Furnace
The campaign duration of furnace refractory linings used in wrought steel production has been increasing dramatically over the past few decades. In the 1970's, a lining campaign of 2,000 heats was considered excellent while today more than 20,000 heats per lining can be achieved. This lining campaign extension is the result of many factors such as improved refractory selection, basic slag chemistry, refractory gunning, and slag splashing. The effects of such changes are most pronounced in basic oxygen furnaces and large electric arc furnaces. Smaller electric arc furnaces (EAFs), as used in steel foundries, do not afford the potential for the same dramatic improvements. Although 4 to 5 fold extensions in lining campaigns are possible.
For the past ten years, the researchers at the University of Missouri at Rolla (UMR) have been working with the wrought steel industry to better understand the mechanisms, which govern the wear of furnace refractories. Many new refractory materials have been developed during that same period and have been used successfully by wrought steel producers. But, largely because of elevated costs, these materials have not found widespread usage in steel foundries. The focus of this project is to optimize the refractory systems used in EAFs in the steel foundries. This will be accomplished by determining the best combinations of refractory materials, slag compositions, and melting practice to increase the refractory life in EAFs.