Method for reusing iron-containing by-product and apparatus therefor

Abstract

Provided are a method for reusing an iron-containing by-product and an apparatus configured to use the method. The method include: forming briquettes by mixing an iron-containing by-product with 5 parts by weight to 20 parts by weight of carbon, based on 100 parts by weight of the iron-containing by-product; preliminarily reducing the briquettes within a temperature range of 800° C. to 1300° C.; and supplying the preliminarily reduced briquettes to an electric furnace. The apparatus includes: a reducing furnace in which briquettes formed by mixing an iron-containing by-product with 5 parts by weight to 50 parts by weight of carbon, based on 100 parts by weight of the iron-containing by-product is reduced within a temperature range of 800° C. to 1300° C.; and an electric furnace to which the preliminarily reduced briquettes are supplied.

1 . A method for reusing an iron-containing by-product, the method comprising:
 forming briquettes by mixing an iron-containing by-product with 5 parts by weight to 20 parts by weight of carbon, based on 100 parts by weight of the iron-containing by-product;   preliminarily reducing the briquettes within a temperature range of 800° C. to 1300° C.; and   supplying the preliminarily reduced briquettes to an electric furnace.   
     
     
         2 . The method of  claim 1 , wherein the iron-containing by-product comprises at least one selected from the group consisting of dust, scale, and sludge. 
     
     
         3 . The method of  claim 2 , wherein the iron-containing by-product comprises dust in an amount of 40 wt % to 60 wt %, scale in an amount of 30 wt % to 50 wt %, and sludge in an amount of 5 wt % to 10 wt %. 
     
     
         4 . The method of  claim 1 , wherein the briquettes have an average diameter of 10 mm to 50 mm and an apparent density of 3000 kfg/cm 3  to 6000 kgf/cm 3 , and a carbon material having a compressive strength of 20 kfg/cm 3  to 100 kgf/cm 3  is included in the briquettes. 
     
     
         5 . The method of  claim 1 , wherein in the preliminarily reducing of the briquettes, the temperature range is maintained by sensible heat of exhaust gas of the electric furnace and combustion heat provided by a burner. 
     
     
         6 . The method of  claim 1 , further comprising combusting exhaust gas of the electric furnace by supplying the exhaust gas to be combusted during the preliminarily heating of the briquettes. 
     
     
         7 . The method of  claim 1 , wherein a fluid used to transfer the briquettes is an inert gas. 
     
     
         8 . The method of  claim 7 , wherein the inert gas is selected from the group consisting of nitrogen gas and argon gas. 
     
     
         9 . The method of  claim 1 , wherein the preliminarily reduced briquettes have a degree of reduction within a range of 10% to 80%. 
     
     
         10 . The method of  claim 1 , further comprising supplying carbon powder to the electric furnace to cause a direct reduction reaction. 
     
     
         11 . An apparatus for reusing an iron-containing by-product, the apparatus comprising:
 a reducing furnace in which briquettes formed by mixing an iron-containing by-product with 5 parts by weight to 50 parts by weight of carbon, based on 100 parts by weight of the iron-containing by-product is reduced within a temperature range of 800° C. to 1300° C.; and   an electric furnace to which the preliminarily reduced briquettes are supplied.   
     
     
         12 . The apparatus of  claim 11 , wherein the reducing furnace comprises a burner. 
     
     
         13 . The apparatus of  claim 11 , further comprising a scrap preheating furnace.