Method for producing residue coal

Abstract

In a method for producing residue coal according to the present invention, a solvent is separated by evaporation from a solid material concentrate, which has been separated in a gravity settling vessel ( 7 ), in a solvent separator ( 10 ), thereby producing a residue coal mixture in which the solvent is remained in the residue coal. Subsequently, the remaining solvent is separated by evaporation from the residue coal mixture in a drier ( 11 ), thereby producing the residue coal. In the drier ( 11 ), the remaining solvent is separated by evaporation from the residue coal mixture utilizing a heat the residue coal mixture itself has. In this manner, an apparatus for drying the residue coal mixture can be simplified, and the cost required for the drying can be reduced.

1 . A method for producing a by-product coal, comprising:
 (1) heating a slurry prepared by mixing a coal and a solvent, thereby extracting a coal component soluble in the solvent;   (2) separating the slurry which has been obtained in the extraction (1) into a solution in which the coal component soluble in the solvent is dissolved and a solid-content concentrated liquid in which a coal component insoluble in the solvent is concentrated; and   (3) evaporating and separating the solvent from the solid-content concentrated liquid which has been separated in (2), thereby acquiring a by-product coal,   wherein (3) comprises:   (3a) evaporating and separating the solvent from the solid-content concentrated liquid which has been separated in (2), thereby acquiring a by-product coal mixture containing a by-product coal in which the solvent remains; and   (3b) evaporating and separating the remaining solvent from the by-product coal mixture, thereby acquiring the by-product coal,   wherein, in (3b), the remaining solvent is evaporated and separated from the by-product coal mixture by exploiting heat that the by-product coal mixture itself has.   
     
     
         2 . The method for producing a by-product coal according to  claim 1 , wherein a temperature of the solid-content concentrated liquid to be fed to (3a) is adjusted so that the by-product coal mixture to be fed to (3b) has a calorific value allowing the remaining solvent to be evaporated and separated from the by-product coal mixture. 
     
     
         3 . The method for producing a by-product coal according to  claim 2 , wherein the temperature of the solid-content concentrated liquid to be fed to (3a) is adjusted by heating at least one of the slurry to be fed to (2) and the solid-content concentrated liquid to be fed to (3). 
     
     
         4 . The method for producing a by-product coal according to  claim 1 ,
 wherein (2) is performed under a pressurized condition, and   in (3a), the solvent is evaporated and separated from the solid-content concentrated liquid by spraying the solid-content concentrated liquid which has been in a high-temperature high-pressure condition, which does not allow the solvent to be evaporated and separated, into a normal-pressure tank.   
     
     
         5 . The method for producing a by-product coal according to  claim 2 ,
 wherein (2) is performed under a pressurized condition, and   in (3a), the solvent is evaporated and separated from the solid-content concentrated liquid by spraying the solid-content concentrated liquid which has been in a high-temperature high-pressure condition, which does not allow the solvent to be evaporated and separated, into a normal-pressure tank.   
     
     
         6 . The method for producing a by-product coal according to  claim 3 ,
 wherein (2) is performed under a pressurized condition, and   in (3a), the solvent is evaporated and separated from the solid-content concentrated liquid by spraying the solid-content concentrated liquid which has been in a high-temperature high-pressure condition, which does not allow the solvent to be evaporated and separated, into a normal-pressure tank.