PRODUCTION OF COAL-WATER SLURRY OF LOW-GRADE COAL AND APPARATUS THEREFOR

摘要

PROBLEM TO BE SOLVED: To obtain a high-concn. coal-water slurry (CWM) from low-grade coal such as subbituminous coal or brown coal and simultaneously reduce the production cost of CWM. SOLUTION: After low-grade coal is wet ground to a particle size of 3mm or lower, the resultant coal powder slurry is heated to 300 deg.C or higher and subjected to hot water treatment under pressure in an improvement reactor 22 to give an improved coal slurry, which is then dewatered to give an improved coal cake. While the cake is mixed and kneaded with water and additives to give CWM, the separated filtrate is recovered to be reused as process water for generating the coal powder slurry. A foaming component contained in the filtrate is reused for the flotation treatment with a flotator 13 in a preimprovement treatment system 10.