Patent ID: 8092574

Claim:
A method of producing pig iron, comprising: reducing a cast of a powder which includes total iron of 40% or more and an atomic molar amount of fixed carbon of 0.7 to 1.5 times the atomic molar amount of oxygen compounded with metal oxide reduced in a carbon monoxide atmosphere at 1200° C. in a rotary hearth furnace to produce a reduced iron-containing material having a metal iron ratio of 50 mass % or more and a carbon ratio of 5 mass % or less in an atmosphere at a maximum temperature of 1200° C. to 1420° C. at a ratio of carbon monoxide to carbon dioxide of 0.3 to 1.2 in the reduced zone, and compression-molding the reduced iron-containing material with a roller-type mold at a temperature of 500° C. to 800° C. to produce a reduced iron cast having a conversion diameter of 7 mm to 45 mm and an apparent density of 4.2 g/cm 3 to 5.8 g/cm 3 ; and supplying the reduced iron cast to the iron making blast furnace to produce the molten iron.