METHOD OF STEEL MELTING IN ELECTRIC ARC STEEL-MELTING FURNACES AND LANCE FOR ITS EMBODIMENT Russian patent published in 1998 - IPC

FIELD: metallurgy, more specifically, processes of steel melting in electric arc steel-melting furnaces. SUBSTANCE: method includes loading of charge into furnace, its melting supply to under metal level of streams of oxygen-containing gas inside the stream of protective gas through one or several gas-oxygen lanes; metal tapping from the furnace. Lance is introduced into furnace through opening in furnace side wall and laid on working surface of furnace lining. Streams of oxygen-containing gas and protective gas are supplied to metal from 0.5-0.95 metal bath depth at an angle of 5-110 deg to metal level of still bath. Lance is introduced into furnace after tapping of metal of previous heat, prior to loading into furnace of iron charge, and oxygen-containing gas and protective gas are supplied through lance for 0.2-0.9 total time of steel melting. Metal level in furnace is set below the level of external hole of channel in furnace body. After introduction, the lance is covered with protective metal jacket and its body sides are covered with refractory powder or material. The device for steel melting in electric arc steel-melting furnaces has gas-oxygen lance in the form of concentric outlet pipes and supplying pipelines. Axis of outlet pipes is located at an angle of 50-155 deg to pipeline axes. Lance is coated with refractory lining. Pipelines on the side of outlet pipes have stiffening ribs. Thickness of lining layer on the side of outlet pipes amounts to 1.2-8.0 thicknesses of lining layer from the opposite side. EFFECT: avoided necessity of hearth replacement during replacement of failed lances, continuous blowing of melt bath during the entire period of heat up to its tapping, and prevented losses of metal from furnace through hearth in the case of lance failure. 5 cl, 3 dwg, 1 tbl