Electric Furnace Processes

Abstract

The main furnaces that are used to produce steel through secondary route are electric arc furnaces (EAF) and induction melting furnaces (IMF). Steelmaking by EAF, their development, charge modification and design aspect are discussed. DC-EAF and IMF are also discussed. The quality steels are efficiently produced in EAF using steel scrap. Major problem faced by steelmakers was short supply, fluctuating prices and extremely heterogeneous nature of scrap. Sponge iron/HBI has uniform chemical and physical characteristics and it hardly contains any tramp metallic elements and has low sulphur content. The partial/total replacement of scrap by sponge iron/HBI is used as feed materials in EAF for quality steel production. EAF steelmakers also prefer to charge hot metal from a mini-blast furnace directly in the EAF to improve productivity, decrease consumption of electric power and cost of production. The new process, CONARC, which is half BOF and half EAF, i.e. combines oxygen converter and electric arc furnace technologies. It employs a twin shell EAF which can economically handle raw material input of solid scrap and hot metal in varying proportions. The EOF, ECOARC, FASTEEL processes and shaft furnace technology are also discussed. Different methods of stainless steel production are described in details.