VERFAHREN UND ANLAGE ZUR GASREDUKTION VON TEILCHENFÖRMIGEN OXIDHÄLTIGEN ERZEN

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 pre-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 off 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 ).