Coating material for use in direct-reduction iron production, and production method therefor

Abstract

A coated raw material for use in direct reduction ironmaking is disclosed. The coated raw material includes: a raw material containing an iron oxide; and a coating layer containing particles adhered to a surface of the raw material, and the particles include at least one selected from the group consisting of a calcium compound and cement, and have a particle size of not smaller than 0.010 mm. The particles preferably have a particle size of not smaller than 0.050 mm. An adhesion amount of the particles is preferably not less than 0.10 mass % and not more than 3.00 mass % based on the raw material. The calcium compound preferably contains at least one selected from the group consisting of calcium oxide and calcium hydroxide.

1 . A coated raw material for use in direct reduction ironmaking, the coated raw material comprising:
 a raw material containing an iron oxide; and   a coating layer containing particles adhered to a surface of the raw material,   wherein the particles include at least one selected from the group consisting of a calcium compound and cement, and have a particle size of not smaller than 0.010 mm.   
     
     
         2 . The coated raw material according to  claim 1 , wherein the particles have a particle size of not smaller than 0.050 mm. 
     
     
         3 . The coated raw material according to  claim 1 , wherein an adhesion amount of the particles is not less than 0.10 mass % and not more than 3.00 mass % based on the raw material. 
     
     
         4 . The coated raw material according to  claim 1 , wherein the calcium compound contains at least one selected from the group consisting of calcium oxide and calcium hydroxide. 
     
     
         5 . A method of producing a coated raw material for use in direct reduction ironmaking, the method comprising:
 preparing a treatment liquid in a slurry form by suspending particles in water, the particles containing at least one selected from the group consisting of a calcium compound and cement and having a particle size of not smaller than 0.010 mm,   coating a surface of a raw material containing an iron oxide with the treatment liquid, and   removing moisture contained in the treatment liquid by heating the raw material coated with the treatment liquid.   
     
     
         6 . The method of producing a coated raw material according to  claim 5 , wherein the particles have a particle size of not smaller than 0.050 mm. 
     
     
         7 . The method of producing a coated raw material according to  claim 5 , wherein the calcium compound contains at least one selected from the group consisting of calcium oxide and calcium hydroxide. 
     
     
         8 . The method of producing a coated raw material according to  claim 5 , wherein an immersion method or a spray method is used to coat a surface of the raw material with the treatment liquid. 
     
     
         9 . The coated raw material according to  claim 2 , wherein an adhesion amount of the particles is not less than 0.10 mass % and not more than 3.00 mass % based on the raw material. 
     
     
         10 . The coated raw material according to  claim 2 , wherein the calcium compound contains at least one selected from the group consisting of calcium oxide and calcium hydroxide. 
     
     
         11 . The coated raw material according to  claim 3 , wherein the calcium compound contains at least one selected from the group consisting of calcium oxide and calcium hydroxide. 
     
     
         12 . The coated raw material according to  claim 9 , wherein the calcium compound contains at least one selected from the group consisting of calcium oxide and calcium hydroxide. 
     
     
         13 . The method of producing a coated raw material according to  claim 6 , wherein the calcium compound contains at least one selected from the group consisting of calcium oxide and calcium hydroxide. 
     
     
         14 . The method of producing a coated raw material according to  claim 6 , wherein an immersion method or a spray method is used to coat a surface of the raw material with the treatment liquid. 
     
     
         15 . The method of producing a coated raw material according to  claim 7 , wherein an immersion method or a spray method is used to coat a surface of the raw material with the treatment liquid. 
     
     
         16 . The method of producing a coated raw material according to  claim 13 , wherein an immersion method or a spray method is used to coat a surface of the raw material with the treatment liquid.