Patent ID: 7713329

Claim:
A method for manufacturing molten iron, comprising: producing an iron-containing mixture by drying and mixing particles of iron-containing ores and additives; passing the iron-containing mixture through first to third successively-connected fluidized beds in the presence of reducing gas so that the mixture is reduced and calcined and thereby converted into a reduced material; forming a coal packed bed, which is a heat source in which the reduced material has been melted; charging the reduced material to the coal packed bed and supplying oxygen to the coal packed bed to manufacture iron; and supplying reduced gas exhausted from the coal packed bed to the fluidized bed, wherein converting the mixture into the reduced material comprises: (a) supplying the reducing gas to the third fluidized bed; (b) supplying reducing gas which passed through the third fluidized bed to the second fluidized bed; (c) supplying reducing gas which passed through the second fluidized bed to the first fluidized bed; (d) preheating the mixture in the first fluidized bed; (e) pre-reducing the preheated mixture in the second fluidized bed; and, (f) finally reducing the pre-reduced mixture in the third fluidized bed and converting the mixture into the reduced material; wherein each fluidized bed comprises a dispersing plate; and, wherein a stream of the reducing gas is heated by injected oxygen gas and is partially combusted in (a) to (c), and oxygen gas is directly injected to the reducing gas that passes through a dispersing plate to be partially combusted in (d) to (f).