Method for producing reduced iron agglomerate

Abstract

Provided is a method for producing a reduced iron agglomerate, which comprises introducing an agglomerate comprising an iron-oxide-containing substance, a carbonaceous reducing agent, a melting point adjuster and an aid for the melting point adjuster onto a furnace bed of a moving-bed-type heating furnace and then heating the agglomerate on the furnace bed to reduce iron oxide in the agglomerate; and melting the resultant product by additional heating to cause the coalescence of an iron component, thereby producing the reduced iron agglomerate, wherein an agglomerate containing the melting point adjuster that has an average particle diameter of 0.3 mm or less and in which the content of a particle diameter of 0.5 mm or less in an amount of 55 mass % or more is used. Thus, provided is a method which can improve the yield of a reduced iron agglomerate having a large particle diameter and can also reduce the amount of time required for the production of the reduced iron agglomerate to improve the productivity of the reduced iron agglomerate.

1 . A method for producing a reduced iron agglomerate, comprising:
 introducing an agglomerate comprising an iron oxide-containing substance, a carbonaceous reducing agent, a melting-point adjuster, and an aid for the melting-point adjuster onto a hearth of a moving-bed heating furnace;   heating the agglomerate to reduce the iron oxide-containing substance; and   melting the agglomerate by further heating the agglomerate to coalesce an iron component,   wherein the melting-point adjuster has;   an average particle diameter of 0.3 mm or less, and   a content of particles having a diameter of 0.5 mm or less of 55% by mass or more, based on a total mass of the melting-point adjuster.   
     
     
         2 . The method according to  claim 1 , wherein the melting-point adjuster is at least one of dolomite and limestone. 
     
     
         3 . The method according to  claim 1 , wherein the aid is fluorite. 
     
     
         4 . The method according to  claim 1 , wherein the melting-point adjuster is present in a central portion of the agglomerate. 
     
     
         5 . A method for producing a reduced iron agglomerate, comprising
 introducing an agglomerate comprising an iron oxide-containing substance, a carbonaceous reducing agent, a melting-point adjuster, and an aid for the melting-point adjuster onto a hearth of a moving-bed heating furnace;   heating the agglomerate to reduce the iron oxide-containing substance; and   melting the agglomerate by further heating the agglomerate to coalesce an iron component,   wherein the aid has:   an average particle diameter of 90 μm or less, and   a content of particles having a diameter of 50 μm or less of 35% by mass or more, based on a total mass of the aid.   
     
     
         6 . The method according to  claim 5 , wherein the melting-point adjuster is at least one of dolomite and limestone. 
     
     
         7 . The method according to  claim 5 , wherein the aid is fluorite.