A Two-Stage Electric Arc-Electroslag Process For Continuous Steelmaking

CIM Bulletin, Vol. 70, No. 785, 1977

R. H. Nafziger, Research Chemist, G. L. Hundley, Chemical Engineer, and R. R. Jordan, Metallurgist, U.S. Department of the Interior, Bureau of Mines, Albany Metallurgy Research Center, Albany, Oregon.

A novel process has been developed for preparing directly workable steel ingots from prereduced iron ore pellets by a two-stage process. The pellets are continuously charged into an electric arc furnace, where molten metal is separated from the gangue. The molten metal flows out of this furnace through a hollow nonconsumable graphite electrode immersed in a molten flux in an elec-troslag furnace. The molten metal solidifies on a continuously withdrawing base plate to form the ingot. A variety of standard carbon and alloy steel ingots, free of porosity, were produced using suitable decarburizers and ferroalloy additions. Some advantages of the two-stage process include: (a) consumable electrode fabrication is eliminated; (b) no expensive deoxidizers are required; (c) the uncontaminated electroslag flux can be reused; (d) energy consumption averages 25% less than in a conventional electric arc - electroslag operation; and (e) the operation is continuous.

Mots Clés: Steelmaking, Electric arc furnaces, Electro-slag process, Pellets, Furnaces, Ingots.