Slag foaming in electric arc furnace (EAF) steelmaking

Slag foaming in electric arc furnace (EAF) steelmaking plays a crucial role in enhancing productivity by protecting refractories and enabling higher power input. The objective of this study is to investigate the mechanisms of slag foaming, specifically focusing on the interactions between carbon and FeO in the slag that produce CO to generate foam. Methodologically, a combination of experimental measurements and theoretical analysis was employed to understand the foamability of EAF type slag, particularly through the measurement of foam height in relation to the superficial gas velocity via the foam index concept. Results revealed that varying the size of bubbles affects the stability of the foam, with smaller bubbles leading to a more stable foam. Furthermore, findings indicate that maintaining a balance between carbon and oxygen injection is essential for optimal foam production, as both deficiencies can adversely affect slag properties and iron yield. The study emphasizes the importance of precise control of gas flow rates and reagent interactions in improving the efficiency of EAF processes.