VERFAHREN ZUR HERSTELLUNG VON STAHL

摘要

A method for producing steel from fine-grained iron ores includes the step of preheating and partially reducing the fine-grained iron ores in a countercurrent heat exchanger. The preheated and partially reduced fine-grained iron ores are then reduced in a fluidized bed reactor to form sponge iron. The reduction in the fluidized bed reactor is effected with exhaust gases which consist substantially of carbon monoxide and which emanate from a melting vessel in which sponge iron is melted. The fine-grained sponge iron produced in the fluidized bed reactor is separated from the reduction gases which form during the reduction in the fluidized bed reactor. The separated fine-grained sponge iron is pneumatically transported into a carbon containing melt in the melting vessel. The transported sponge iron is melted and subjected to a final reduction in the metal melt with the carbon in the metal melt and with further carbonaceous material which is pneumatically introduced into the metal melt. The melt is refined with pure oxygen. The oxygen, carbonaceous material and sponge iron are introduced into the metal melt through at least one nozzle which is disposed below the level of the metal melt surface.