HOT METAL MANUFACTURING METHOD CAPABLE OF CONTROLLING CALCINATION RATIO OF SUBSIDIARY RAW MATERIALS

摘要

PURPOSE: A hot metal manufacturing method capable of controlling calcination ratio of subsidiary raw materials is provided to reduce fuel consumption by improving calcination ratio of subsidiary raw material constituents in a process of manufacturing reduced iron fine containing subsidiary raw material constituents into briquette. CONSTITUTION: In a hot metal manufacturing process using a hot metal manufacturing system comprising a fluidized bed reduction furnace(200) consisting of one or more stages of reactors for fluidization reducing iron ore fine having wide particle size distribution and subsidiary raw materials, an agglomerator charging hopper(300) for storing reduced iron fine containing subsidiary raw materials reduced in the fluidized bed reduction furnace and discharged from the fluidized bed reduction furnace, an agglomerator(310) for manufacturing briquette from the reduced iron fine supplied from the charging hopper, a separator(320) separating a plurality rows of briquettes agglomerated in the agglomerator into individual briquette, a melting furnace for producing hot metal by melting the briquette separated in the separator and supplying flue gas of the hot metal to reduced gas of the fluidized bed reduction furnace, and a melting furnace cyclone(510) for resupplying dust into the melting furnace and supplying gas to the reduced gas of the fluidized bed reduction furnace by collecting flue gas generated from the melting furnace, the hot metal manufacturing method comprises the step of staying reduced iron fine containing subsidiary raw materials discharged from the fluidized bed reduction furnace in the agglomerator charging hopper containing a nitrogen atmospheric gas and having a temperature of 650 to 800 deg.C for 30 to 60 minutes.