By covering the arc and melt surface with foamy slag, heat losses through radiation from the melt can be reduced. Foamy slag can be obtained by injecting carbon (granular coal) and oxygen, or by lancing of oxygen only. Slag foaming increases the electric power efficiency by at least 20% in spite of a higher arc voltage. Besides energy savings, foamy slag practices may also inrease productivity by reducing tap-to-tap times.  

This practice requires closer control of fluxes. In most cases it is done manually by the furnace operator.  

   This technology has high application potential for China, India and the United States.