Resource saving and reserves of increasing efficiency of steelmaking in electric arc furnaces

Abstract

The work presents the results of analysis of heat operation of various steelmaking arc furnaces. The ways of increasing efficiency of steelmaking in EAF by special measures decreasing the waste of metal and rational energy and technological regimes of melting are considered. Waste of metal can be reduced by placing the charge in the basket with account for apparent density of components; supplying the coolant (pellets, slagformers, fine scrap etc.) to arc burning zone from the moment of formation of liquid bath under the electrodes and to oxygen blowing zones; blowing the bath with oxygen providing distribution of the zone of reactions of melt element oxidation throughout the bath; forced stirring of the metal; decreasing the metal temperature at tapping. Rationalization of operating regimes of the furnace includes increasing the introduced electric power; optimizing current mode; reducing the working time of gas-oxygen burners to 40–50 % of the melting time with oxygen / natural gas ratio maintained 2 : 1, which provides the maximum flame temperature; establishing gas and oxygen consumption taking into account the thermal conditions in the working chamber; synchronized operation of all gas-oxygen devices; balanced consumption of oxygen during melting in order to decrease metal evaporation; application of the regime of afterburning of waste gases; timely injection of carbon-bearing material for sponging the slag, etc.