MANUFACTURE OF IRON AND STEEL IN A DUPLEX SMELTER AND SOLID STATE OXIDE SUSPENSION PREREDUCER

摘要

Prereduced iron oxides are supplied to a smelting vessel (1) for the production of iron or steel by directing a hot reducing offgas from the vessel (1) into a vertical riser duct (8) without substantial cooling of the offgas and, by way of inlet (16), particulate iron oxide containing material is entrained in the hot reducing offgas as the gas is conveyed upwardly through the duct (8). The hot gas heats the entrained material to a temperature at which partial reduction of the iron oxide occurs, the hot gas thereby losing sensible heat. Additional materials may be introduced to the duct (8) for entrainment in the gas. Particulate material is separated in a cyclone (9) from the gas and the separated partially reduced material is introduced to the smelting vessel by way of passage (12). The particulate material, or part of it, may be recycled by way of passage (15) through the vertical riser duct before the partially reduced material is introduced to the smelting vessel and only part of the hot reducing offgas emitted by the vessel may be directed into the duct.