Process for producing molten steel using particulate metallic iron

摘要

A process for producing a molten steel (G) is disclosed in which particulate metallic iron can be more efficiently melted. The process includes the step of melting, in an electric arc furnace (2), all charge for iron which comprises: particulate metallic iron (A) produced by a method including a step in which a feed material comprising a carbonaceous reducing material and an iron oxide-containing substance is heated in a rotary hearth furnace (1) as a reducing/melting furnace and the iron oxide contained in the feed material is thereby reduced in the solid state to yield metallic iron and a step in which the resultant metallic iron is heated to a higher temperature to melt the metallic iron and the molten iron is aggregated while separating the iron from the slag (B); and scraps (D) which are another feed material for iron. The process is characterized in that the content of carbon in the particulate metallic iron (A) is regulated to 1.0-4.5 mass% and the carbon in the particulate metallic iron (A) is burned by oxygen blowing. The process is further characterized in that the particulate metallic iron (A) is used in an amount of 40-80 mass% with respect to all charge for iron and that the scraps (D) are initially introduced into the electric arc furnace (2) to obtain molten iron (F) and then the particulate metallic iron (A) is continuously introduced into the molten iron (F).