Title

ELECTRIC ARC FURNACE SIDE-WALL FIX INJECTORS1 DEVELOPMENTS AND OPERATIONAL RESULTS

ELECTRIC ARC FURNACE SIDE-WALL FIX INJECTORS1 DEVELOPMENTS AND OPERATIONAL RESULTS

Authorship

Candusso, Claudio; Iacuzzi, Massimo; Marcuzzi, Simone; Tolazzi, Daniele

Candusso, Claudio

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Iacuzzi, Massimo

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Marcuzzi, Simone

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Tolazzi, Daniele

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DOI

10.5151/2594-5300-0068

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Abstract

The Electric Arc Furnace continues to evolve into a highly efficient melting unit, using less electric energy and more carbonaceous fuel generated energy. In recent years, steel-makers have looked for chemical energy injection systems to reduce the energy cost, to promote more stable and predictable chemical reactions into the melting process so as to achieve better recovery rates and improve conversion costs as a final result. The improved practice includes: • Side-wall injection of carbon, oxygen and lime through multiple fixed lances that allow a closed furnace operation. •Calibrated additions of carbon, oxygen and lime to optimize FeO content in the slag, improve foamy slag characteristics and lower residual tramp gasses into tapped steel. •Precise control of oxygen injection to satisfy chemical energy exothermic reactions. The evolving technology deploys furnace side-wall fixed units that can act as high-fire burners and multi-stream supersonic jets of oxygen and powdered solids. Although several manufacturers supply systems that provide injection of oxygen for successful decarburisation and for oxidation reactions, the efficient injection of solids, such as fuel carbon and foaming carbon, or lime and dolomite for slag conditioning, has always represented a challenge. MORE has recently developed new coaxial injection systems, based on BOC Gases original patented technologies, that shroud and enhance solids propulsion with supersonic oxygen and/or flame. A reduced number of injectors, that require low capital investment and minimal maintenance costs, ensure now a much better recovery rate of all injected solid particles. The application of the new injection technologies, and related operational results achieved in several EAF with different charge mixes, are herein described.

The Electric Arc Furnace continues to evolve into a highly efficient melting unit, using less electric energy and more carbonaceous fuel generated energy. In recent years, steel-makers have looked for chemical energy injection systems to reduce the energy cost, to promote more stable and predictable chemical reactions into the melting process so as to achieve better recovery rates and improve conversion costs as a final result. The improved practice includes: • Side-wall injection of carbon, oxygen and lime through multiple fixed lances that allow a closed furnace operation. •Calibrated additions of carbon, oxygen and lime to optimize FeO content in the slag, improve foamy slag characteristics and lower residual tramp gasses into tapped steel. •Precise control of oxygen injection to satisfy chemical energy exothermic reactions. The evolving technology deploys furnace side-wall fixed units that can act as high-fire burners and multi-stream supersonic jets of oxygen and powdered solids. Although several manufacturers supply systems that provide injection of oxygen for successful decarburisation and for oxidation reactions, the efficient injection of solids, such as fuel carbon and foaming carbon, or lime and dolomite for slag conditioning, has always represented a challenge. MORE has recently developed new coaxial injection systems, based on BOC Gases original patented technologies, that shroud and enhance solids propulsion with supersonic oxygen and/or flame. A reduced number of injectors, that require low capital investment and minimal maintenance costs, ensure now a much better recovery rate of all injected solid particles. The application of the new injection technologies, and related operational results achieved in several EAF with different charge mixes, are herein described.

Keywords

Chemical energy; Foaming slag; Supersonic oxygen injection; Sonic carbon injection; Lime injection.

Chemical energy; Foaming slag; Supersonic oxygen injection; Sonic carbon injection; Lime injection.