Method of producing ashless coal

Abstract

A method of producing ashless coal used in caking coal for coke for iron making includes a slurry preparation step (S 1 ) of mixing a solvent with coal to prepare a slurry; an extraction step (S 2 ) of extracting the slurry obtained in the slurry preparation step (S 1 ) at a temperature in the range of 400° C. to 420° C. for 20 minutes or less, and then cooling the slurry to 370° C. or lower; a separation step (S 3 ) of separating the slurry obtained in the extraction step (S 2 ) into a liquid portion and a non-liquid portion; and an improved-coal-obtaining step (S 4 ) of separating the solvent from the liquid portion separated in the separation step (S 3 ) to obtain ashless coal which is improved coal.

1 . A method of producing ashless coal used in caking coal for coke for iron making, comprising:
 preparing a slurry by mixing a solvent with coal;   extracting the prepared slurry at a temperature of from 400° C. to 420° C. for 20 minutes or less, and then cooling the slurry to a temperature of 370° C. or lower;   separating the extracted slurry into a liquid portion and a non-liquid portion; and   separating the solvent from the separated liquid portion to obtain ashless coal.   
   
   
       2 . The method of producing ashless coal according to  claim 1 , further comprising separating the solvent from the separated non-liquid portion to obtain residue coal. 
   
   
       3 . The method of producing ashless coal according to  claim 1 , wherein extracting the prepared slurry comprises heating to and extracting at a temperature in the range of 400° C. to 420° C. and then immediately cooling to a temperature of 370° C. or lower. 
   
   
       4 . The method of producing ashless coal according to  claim 1 , wherein the coal is low-quality coal. 
   
   
       5 . the method of producing ashless coal according to  claim 2 , wherein the coal is low-quality coal. 
   
   
       6 . The method of producing ashless coal according to  claim 3 , wherein the coal is low-quality coal. 
   
   
       7 . The method of producing ashless coal according to  claim 2 , wherein extracting the prepared slurry comprises heating to and extracting at a temperature in the range of 400° C. to 420° C. and then immediately cooling to a temperature of 370° C. or lower.