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A continuous steelmaking process for electric arc furnaces which is said to feature continuous charging of feedstock, continuous furnace operation at full power without stopping, significantly increased productivity, and higher quality steel, has been developed by Intersteel Technology Inc. of Charlotte, North Carolina, USA.
Called Consteel, an acronym for Continuous Steelmaking, the technology is adaptable to the conventional EAF, and the DC furnace in the production of carbon, alloy, and quality steel to be processed by continuous casting.
Compared to all electric melting operations in conventional EAF's, Consteel is claimed to give an increase in productivity of 40% without use of feedstock preheating, 85% when preheating with furnace off-gas and 150% when preheating to 900°C with fuel. Electric energy consumption when preheating to 900°C is approximately 280kWhr/t or 254kWhr/short ton which is especially attractive in those regional areas where electrical energy is relatively expensive.
Through continuous steelmaking, it is said that energy consumption can be reduced by up to 30%, electrode consumption by up to 40% and manpower up to 60%. Overall cost savings are approximately US $ 25 per net ton of billet. With the process, a ladle of steel can be tapped every 40 to 50 min.
Although the process makes possible carbon injection and intensive use of oxygen to decrease both specific electric energy and preheating fuel consumption in a larger measure than is feasible in conventional operation, the concept is on the basis of continuous feeding of preheated scrap and electric melting.
A DC furnace, a conventional EAF furnace or a plasma furnace are the...