Method for making reduced iron

A method for making reduced iron using blast-furnace sludge, comprising:

• a mixing step of mixing the blast-furnace sludge and an iron-oxide-containing powder to prepare a mixed material;
• an agglomerating step of agglomerating the mixed material to form agglomerates;
• a feeding step of feeding the agglomerates onto a continuously moving hearth;
• and
• a reducing step of heating the agglomerates to remove zinc as well as to reduce the agglomerates, wherein the mixed material is prepared so that the excess carbon ratio Sc satisfies the relationship:
• Sc≦8−2NL
• wherein Sc=XC−(12/16)·XO, NL represents an average number of layers of the agglomerates on the moving hearth, XC represents the mass ratio (percent by mass) of carbon in the agglomerates in a dry state, and XO represents a total mass ratio (percent by mass) of oxygen in iron oxide and oxygen in zinc oxide in the dry agglomerates.

A method for making reduced iron using blast-furnace sludge, comprising:

• a disintegrating step of disintegrating the blast-furnace sludge containing pseudoparticles having a diameter exceeding 1 mm so as to reduce the ratio the pseudoparticles having the diameter exceeding 1 mm to the mixed material to 50% or less;
• a mixing step of mixing the blast-furnace sludge and an iron-oxide-containing powder to prepare a mixed material;
• an agglomerating step of agglomerating the mixed material to form agglomerates;
• a feeding step of feeding the agglomerates onto a continuously moving hearth;
• and
• a reducing step of heating the agglomerates to remove zinc as well as to reduce the agglomerates.