Patent ID: 7780759
Filing Date: 2010-08-24
Classification: C21B,C22B,Y02P

Abstract:
1. A circulating fluidized bed process for direct reduction of a solid metalliferous material having a particle size distribution that at least in part comprises micron sized particles, said process comprising: supplying the metalliferous material, a solid carbonaceous material, an oxygen-rich gas and a fluidizing gas to a vessel, whereby a fluidized bed is maintained in the vessel, the fluidized bed containing a carbon-rich zone, withdrawing gas and entrained solids from an upper section of the vessel, separating solids from the withdrawn gas, and recirculating the separated solids to the vessel, and discharging a product stream from a lower section of the vessel, wherein the step of supplying the oxygen-rich gas comprises injecting the oxygen-rich gas downwardly into the carbon-rich zone using a cooled lance spaced horizontally inward from side walls of the vessel, whereby heat is generated in the carbon-rich zone by reactions between oxygen and metallized material, the solid carbonaceous material and other oxidizable solids and gases in the fluidized bed, metalliferous material is at least partially reduced in a metal-rich zone below the carbon-rich zone, and the product stream discharged from the vessel comprises the at least partially reduced metalliferous material, and wherein the process further comprises controlling agglomeration of particles by adjusting at least one of feed rate of the metalliferous material, feed rate of the carbonaceous material and feed rate of the oxygen-rich gas.