PROCESSO PARA PRODUCAO DE ACO A PARTIR DE OXIDOS DE FERRO;A CONVERSAO DE OXIDOS DE FERRO EM CARBURETO DE FERRO;A CONVERSAO DE CARBURETO DE FERRO EM ACO;NO FORNO DE OXIGENIO BASICO;A FABRICACAO DE ACO A PARTIR DE CARBURETO DE FERRO NO FORNO DE OXIGENIO BASICO;E A CONCENTRACAO DE MINERIOS DE FERRO NAO-MAGNETICOS DE BAIXO TEOR

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.