Granular metallic iron

Abstract

Metallic iron nuggets made by reducing-melt of a material containing a carbonaceous reductant and a metal-oxide-containing material, the metallic iron nuggets comprising at least 94% by mass, hereinafter denoted as “%”, of Fe and 1.0 to 4.5% of C, and having a diameter of 1 to 30 mm are disclosed.

1 - 7 . (canceled)  
   
   
       8 . A method of making metallic iron nuggets, the method comprising 
 mixing together a carbonaceous reductant and a metal oxide to form a mixture; and    heating the mixture to produce the metallic iron nuggets, wherein    almost all of the metallic iron nuggets produced by the heating of the mixture have a diameter in a range of from 1 to 30 mm and comprise at least 94 mass % of metallic Fe and 1.0 to 4.5 mass % of C.    
   
   
       9 . The method according to  claim 8 , wherein 98% or more of the metallic iron nuggets produced by the heating of the mixture have a diameter in a range of from 1 to 30 mm and comprise at least 94 mass % of metallic Fe and 1.0 to 4.5 mass % of C.  
   
   
       10 . The method according to  claim 8 , wherein all of the metallic iron nuggets produced by the heating of the mixture have a diameter in a range of from 1 to 30 mm and comprise at least 94 mass % of metallic Fe and 1.0 to 4.5 mass % of C.  
   
   
       11 . The method according to  claim 8 , wherein the metallic iron nuggets further comprise 0.20 mass % or less of sulfur.  
   
   
       12 . The method according to  claim 8 , wherein the metallic iron nuggets further comprise 0.02 to 0.5 mass % Si and less than 0.3 mass % Mn.  
   
   
       13 . The method according to  claim 8 , wherein 
 the heating reduces the metal oxide in a solid state to form a reduced iron; and    the method further comprises heating the reduced iron in a reducing atmosphere to carburize and melt the reduced iron.    
   
   
       14 . The method according to  claim 8 , further comprising adding a CaO source to the mixture to adjust the basicity (CaO/SiO 2 ) of a slag component in the mixture to 0.6 to 1.8.  
   
   
       15 . The method according to  claim 8 , wherein the metallic iron nuggets further comprise less than 0.08 mass % of sulfur.  
   
   
       16 . The method according to  claim 8 , further comprising adjusting an amount of the carbonaceous reductant in the mixture so that the residual carbon content at a metallization ratio of 100% after reduction by heating is 1.5 to 5.0%.  
   
   
       17 . The method according to  claim 10 , wherein the metallic iron nuggets have a uniform diameter.  
   
   
       18 . The method according to  claim 8 , wherein 98% or more of the metallic iron nuggets produced by the heating of the mixture have a diameter in a range of from 5 to 30 mm and comprise at least 94 mass % of metallic Fe and 1.0 to 4.5 mass % of C.