PROCESS FOR THE PRODUCTION OF STEEL FROM IRON OXIDES; THE CONVERSION OF IRON OXIDES TO IRON CARBURETUM; THE CONVERSION OF IRON CARBURET IN STEEL; IN THE BASIC OXYGEN OVEN; OF BASIC OXYGEN AND THE CONCENTRATION OF LOW NON-MAGNETIC IRON ORES

摘要

Steel is obtd. directly from iron oxides by (a) converting the iron in the oxides to iron carbide and (b) converting the iron in the iron carbide to steel in a basic oxygen furnace. The heat for operation of the BOF is obtd. by oxidising the carbon of the iron carbide to carbon monoxide. Pref. the oxides are reduced and the iron converted to iron carbide in one step in a fluidised bed with a mixt. of hydrogen bearing gas and carbon contg. material, the amt. of H2 being 50 (esp. 60)% of the CO present. The iron carbide is added to the BOF and processed to steel without the addn. of external heat. Pref. the steps (a) and (b) are simultaneous and the process is auto-thermal. Steel is obtd. from iron oxide without using a blast furnace. Sources of heat for making the BOF process autothermal are obtd. in situ, i.e. sensible heat from the off-gases or the CO in the off-gases can be burned, or the CO can be reacted with the iron carbide of step (a) to raise the ratio of Fe2C to Fe3C in the charge so that sufficient carbon is available for combustion.