Electric Arc Furnace

1. EAF Introduction
2. Developments in EAF Technology
3. Basic Equipment and Operation
4. Furnace Layout
5. Electrical Equipment
6. Melting
7. Burners
8. Raw Materials
9. Raw Materials Preparation
10. Alloy Yield
11. Electrode Breakage
12. Slag Foaming
13. Slag Foamability
14. Slag Reduction
15. Deslagging
16. Tapping
17. Exercise: EAF Operation
18. EAF Simulation

Foaming slag is used to increase the thermal efficiency of the furnace during the refining period, when the side walls are fully exposed to the arc radiation. A foaming slag will rise and cover the electric arcs, thus permitting the use of a high tap setting without increasing the thermal load on the furnace walls. In addition, an electrical arc covered by a foaming slag will have a higher efficiency in transferring the energy into the steel phase.

Slag foaming is obtained by injecting oxygen into the liquid steel, where mainly iron is oxidized according to the reaction:

O₂ + 2 Fe = 2 (FeO)

Carbon powder is then injected simultaneously into the slag phase where iron oxide is reduced.

(FeO) + C = Fe + CO (g)

The resulting CO gas is a critical component in order to obtain a foaming slag.