Process for the direct reduction of iron-oxide-containing materials

Abstract

There is disclosed a process for the direct reduction of iron-oxide-containing materials by a gasification gas produced in a gasifier by reacting carbon with oxygen and, if desired, with steam, upon the addition of sulfur acceptors in a fluidized bed. The gasification gas is supplied to a direct reduction shaft furnace after separation of solid particles carried therewith. At least part of the top gas withdrawn from the direct reduction shaft furnace is compressed after dust scrubbing and is recycled to the gasifier. The sulfur acceptors are supplied as fine particles separated from the coal in cocurrent with, and/or counterflow to, the fluidized-bed forming gases. The top gas from the reduction shaft furnace, which has a concentration of from 15 to 30% CO.sub.2 and a temperature of from 80.degree. to 800.degree. C., is recycled laterally through the wall of the gasifier into the region of the fluidized bed, which is maintained at a temperature of at least 1,150.degree. C. The slag, which is in the molten state with the temperature prevailing in the gasifier, containing ashes and sulfur compounds and collecting under the formation of a bath, is removed via a tap in the vicinity of the bottom of the gasifier. The solid particles separated from the gasification gas are mixed with dust coal having a grain size of up to 3 mm and are recycled into the bottom region of the gasifier above the surface of the slag bath.