The Increasing use of Prereduced Iron Ores in Electric Arc Furnaces

Abstract

Datas about the increasing use of prereduced iron ores, around the world, in electric arc furnaces.Development of continuous charging system such of these of HyLSA (Mexico), Contimelt (Steko- Luigi) Korf (Georgetown, USA and Hamburg, Germany), TAMSA-TECH1NT (Mexico). Comments about continuous melting: necessity of rea-ching optimal conditions to melt prereducea iron ores i.e. high electrical power, low electrode consumption, low refractory wear of the lining of the furnace. Possibilit-ies, advantage and a difficulties of utilization of electrical intensity in the arcs or shadowing the arcs in the slag. Equipment used for IRSID experiments: 6 t 3000 kVA elec-tric arc furnace with special continuous charging devices. Operating charging and melting pratice with shadowing of the radiation from the arcs bthrough, first, a solid mass of prereduced iron• ores in the center of the furnace and, second, the boiling slag. Main results with a number of samples of prereduced iron ore. Relation between available electrical energy PE and useful power Pu needed to melt and heat metal and slag and to cover the metallurgical reactions. Comparison between scrap and prereduced iron ores charging and melting. Application to commercial plants extrapolation of our tests and operating procedure with recommendation for large scale furnaces.Automation of electric arc furnaces : principles, operating procedures. The next step could be the continuous arc steelmaking furnace.