Foamy Slag Practices

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.  

Chinese flag Indian flag US flag This technology has high application potential for China, India and the United States. 

Development Status Products
Commercial
EAF Steel

Foamy Slag PracticesCosts & Benefits

Parent Process: Electric Arc Furnace
Energy Savings Potential

The net energy savings are estimated at 6-8 kWh/t-steel (Worrell et al., 2010. p. 93).

CO2 Emission Reduction Potential

US flag Emissions reduction of 10.6 Kg CO2/t-steel  is estimated (US EPA, 2010).

Costs

Retrofit capital cost is estimated at $15.6/t-steel (US EPA, 2010).

Foamy Slag Practices Publications

Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry

The U.S. Environmental Protection Agency’s (EPA) energy guide, Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry, discusses energy efficiency practices and technologies that can be implemented in iron and steel manufacturing plants. This guide provides current real world examples of iron and steel plants saving energy and reducing cost and carbon dioxide emissions.

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