Patent ID: 7160353

Claim:
A method for making molten iron, comprising the steps of: feeding a raw material mixture containing an iron oxide material and a carbonaceous reductant into a rotary hearth furnace to reduce iron oxide in the raw material mixture with the carbonaceous reductant into solid reduced iron; transporting the solid reduced iron to a melting furnace; and combustion of a carbonaceous material supplied as fuel to melt the solid reduced iron in the melting furnace for producing molten iron, wherein when the metallization of the solid reduced iron is enhanced to a range of 60% to 80%, the solid reduced iron is transported to the melting furnace, and amounts of oxygen and the carbonaceous material supplied to the melting furnace are controlled so that the secondary combustion ratio of CO gas in the melting furnace is reduced to a range of 20% to 40%; and when the metallization of the solid reduced iron is enhanced to a range of more than 80%, the solid reduced iron is transported to the melting furnace, and amounts of oxygen and the carbonaceous material supplied to the melting furnace are controlled so that the secondary combustion ratio of CO gas in the melting furnace is reduced to a range of 40% or less.