Patent ID: 6379422
Filing Date: 2002-04-30
Classification: C21B,Y02P,Y10S

Abstract:
A process for direct smelting metalliferous feed material which comprises the steps of:(a) partially reducing iron oxides in a solid state in a pre-reduction vessel and producing partially reduced iron oxides; (b) direct smelting partially reduced iron oxides produced in step (a) to molten iron in a direct smelting vessel which contains a molten bat of iron and slag and is supplied with a solid carbonaceous material as a source of reductant and energy and with an oxygen-containing gas for post-combusting carbon monoxide and hydrogen generated in the vessel, the solid carbonaceous material containing sulphur that is volatilised in direct smelting step (b); (c) generating an off-gas that contains sulphur in direct smelting step (b) and releasing the off-gas from the direct smelting vessel; and (d) using a first stream of the off-gas released from the direct smelting vessel in pre-reduction step (a) to pre-reduce iron oxides in the pre-reduction vessel, and using a second stream of the off-gas as a source of energy for heating air or oxygen-enriched air before supplying the air or oxygen-enriched air as the oxygen-containing gas to the direct smelting vessel, wherein the first stream is less than 60% by volume of the off-gas released from the direct smelting vessel.