Method for producing granular metallic iron

Abstract

A method for producing granular metallic iron of the present invention includes: an agglomeration step of obtaining agglomerates through agglomeration of a mixture that contains an iron oxide-containing material and a carbonaceous reducing agent; and a granulation step of obtaining granular metallic iron by heating the agglomerates, reducing iron oxides in the agglomerates, aggregating generated metallic iron to be granular while separating the metallic iron from slag generated as a by-product, and thereafter cooling and solidifying the metallic iron, wherein agglomerates satisfying all the conditions given by formulas (1) to (3) below are used as the agglomerates: (1) [(total CaO amount+total SiO2 amount+total Al2O3 amount)/total Fe amount]≧0.250; (2) (total CaO amount/total SiO2 amount)≧0.9; (3) [total Al2O3 amount/(total CaO amount+total SiO2 amount+total Al2O3 amount)]×100≧9.7. In the formulas, the total CaO amount, the total SiO2 amount, the total Al2O3 amount and the total Fe amount respectively represent the mass percentage of CaO, the mass percentage of SiO2, the mass percentage of Al2O3 and the mass percentage of Fe contained in the agglomerates.

Dependencies are inferred from the claim text.