US Patent 7462219 Production method of metal iron

A method producing metallic iron by reducing raw materials including an iron-oxide containing material and a carbonaceous reducing agent under heating, which can minimize re-oxidization of the metallic iron and can efficiently produce metallic iron having a high metallization ratio and high iron purity at high yield. The method produces metallic iron, by heating raw materials including a carbonaceous reducing agent and an iron-oxide containing material in a reduction melting furnace of the moving hearth type, and reducing and melting iron oxides in the raw materials. The reduction melting furnace is partitioned into at least three zones in a hearth moving direction, at least one partitioned zone upstream in the hearth moving direction is a solid-state reducing zone, at least one downstream partitioned zone is a carburization melting zone, and a reduction aging zone is between the solid-state reducing zone and the carburization melting zone.