METHOD AND INSTALLATION FOR THE INDIRECT REDUCTION OF PARTICULATE OXIDE-CONTAINING ORES

摘要

In a process for the gas reduction of particulate oxide-containing ores, in particular iron--oxide-containing material, in the fluidized-bed process at a pressure of < 5 bars, wherein the ore by aid of a reducing gas produced from coal is heated, optionally also p re- reduced, in a fluidized-bed reactor (1) designed as a pre-heating stage (5), subsequently is reduced to sponge iron in at least one fluidized-bed reactor (2, 3) designed as a reduction stage (7, 8), the reducing gas via a reducing-gas feed duct (12) or reducing-gas duct (13) being conducted from the reduction stage (7, 8) to the pre-heating stage (5) in the opposite direction of the material to be reduced and conducted from stage to stage, and being drawn of f as an export gas after purification, heat is supplied to the reducing gas fed to the reduction stage (7, 8) and/or pre-heating stage (5), namely by combustion, together with oxygen and/or air, of a portion of the reducing gas provided for the gas reduction in the reduction stage (7, 8) and/or the pre-heating stage (5).