Patent ID: 6986800
Filing Date: 2006-01-17
Classification: C21B,C21C,Y02P

Abstract:
1. A method for producing steel in an integrated steel plant, the plant comprising a blast furnace for pig iron production, an oxygen converter for steel production, a coke oven for coke production and a direct reduction reactor for producing direct reduced iron, the method comprising forming a first gas stream having a hydrogen content of at least about 50% by volume and a carbon monoxide content of less than about 10% by volume by withdrawing and conditioning the temperature and pressure of the coke oven effluent gases; forming a second gas stream having a hydrogen content of less than about 10% by volume and a carbon monoxide content of at least about 50% by volume by withdrawing and conditioning the temperature and pressure of oxygen converter effluent gases; forming a third gas stream having a reducing potential greater than about 0.6, a hydrogen content greater than about 30% by volume, and a carbon monoxide content greater than about 30% by volume by mixing the first and second gas streams; forming a fourth gas stream by combining at least a portion of the third gas stream with at least a portion of regenerated gas effluent from the direct reduction reactor; heating the fourth gas stream to a temperature of greater than about 850° C.; reducing iron oxide-containing solid particles in the direct reduction reactor to metallic iron in the form of direct reduction iron by introducing the solid particles and the heated fourth gas stream into the direct reduction reactor; forming a fifth gas stream by withdrawing reacted gas from the direct reduction reactor; forming a sixth gas stream with regenerated reducing potential by removing water and carbon dioxide from at least a portion of the fifth gas stream; using at least a potion of the sixth gas stream in the formation of the fourth gas stream; and charging the direct reduced iron to the blast furnace.