Patent ID: 6224649
Filing Date: 2001-05-01
Classification: C21B,C22B,Y02P

Abstract:
A method for reducing iron-oxide-containing particles present in a broad range of sizes, including fines, to metallic-iron-containing particles in a reducing zone of a moving bed reduction reactor with a reducing gas mainly composed of hydrogen and/or carbon monoxide at a substantially non-agglomerating reducing temperature range, said method comprising:(a) introducing said iron-oxide-containing particles into said reducing zone to form a non-fluidized moving bed of particles in the lower portion of said reducing zone and extending down into a discharge zone of the reactor;(b) injecting said reducing gas into said moving bed, to define thereabove a moving bed second reducing sub-zone, at a regulated velocity sufficient to create and maintain immediately above said moving bed a first reducing sub-zone in the form of a fluidized bed composed of particle fines;(c) withdrawing from the reactor an overflow of the metallic-iron-containing particle fines from the top of said fluidized bed;(d) withdrawing from the non-fluidized moving bed in said discharge zone the reduced metallic-iron-containing particles, including fines; and,(e) withdrawing the spent reducing/fluidizing gas from above said fluidized bed in said reducing zone.