Method for preparing coal to be injected into blast furnace, coal to be injected into blast furnace, and usage of same

Abstract

A method for preparing coal which is to be injected into a blast furnace includes: a step (S 1 ) for analyzing the ash of coal in a raw-coal stage and determining the contents (wt %) of At Si, Ca and Mg in the ash; a step (S 2 ) for deriving the ash melting point of the coal on the basis of the obtained data: a step (S 3 ) for selecting a metal species to be supported on the coal and deriving the amount thereof to be supported on the basis of the obtained data so as to adjust the melting point of the ash of the coal to 1200 to 1400° C.; a step (S 4 ) for making the metal supported on the coal in the derived amount by an ion-exchange method; and a step (S 5 ) for carbonizing the coal obtained in the step ( 4 ).

1 . A method for preparing blast furnace injection coal to be injected through a tuyere into an interior of a blast furnace main body of a blast furnace installation, the method comprising:
 a first step of analyzing ash of run-of-mine coal and weight percentages of Al, Si, Ca, and Mg in the ash;   a second step of deriving an ash melting point of the coal based on data obtained by the analysis;   a third step of selecting a metal species to be supported on the coal and deriving the amount of the metal species to be supported based on data obtained in the first step and the second step to adjust the ash melting point of the coal to 1200 to 1400° C.;   a fourth step of supporting the metal in the amount to be supported onto the coal by an ion exchange method; and   a fifth step of pyrolyzing the coal obtained in the fourth step.   
     
     
         2 . The method for preparing blast furnace injection coal according to  claim 1 , wherein
 the metal is at least one of calcium and magnesium.   
     
     
         3 . The method for preparing blast furnace injection coal according to  claim 1 , wherein
 the coal is thermally treated at 350 to 550° C. in the fifth step to adjust a residual volatile content to 15 to 35%.   
     
     
         4 . The method for preparing blast furnace injection coal according to  claim 1 , wherein
 the amount of the metal to be supported on the coal is 0.2 to 1.55 in terms of (CaO+MgO)/SiO 2  weight ratio.   
     
     
         5 . The method for preparing blast furnace injection coal according to  claim 4 , wherein
 the amount of the metal to be supported on the coal is 0.25 to 1.4 in terms of (CaO+MgO)/SiO 2  weight ratio.   
     
     
         6 . The method for preparing blast furnace injection coal according to  claim 5 , wherein
 the amount of the metal to be supported on the coal is 0.35 to 1 in terms of (CaO+MgO)/SiO 2  weight ratio.   
     
     
         7 . Blast furnace injection coal, which is obtained by the method for preparing blast furnace injection coal according to  claim 1 . 
     
     
         8 . A method for using blast furnace injection coal, the method comprising injecting blast furnace injection coal obtained by the method for preparing blast furnace injection coal according to  claim 1  through a tuyere into an interior of a blast furnace main body of a blast furnace installation.