Method for increasing concentration of coarse coal water slurry

摘要

A method for increasing the concentration of a coarse coal water slurry, comprising the following steps: (1) pre-heating the coarse coal water slurry, the temperature for the pre-heating being 160°C-280°C and the pressure being 0.6-6.4 MPa; (2) heating the pre-heated coarse coal water slurry to a heat preservation temperature so as to perform a heat preservation treatment, the temperature for the heat preservation treatment being 200°C-320°C and the pressure being 1.5-11.3 MPa; (3) leaving the coarse coal water slurry which has been subjected to the heat preservation treatment to stand, the standing time being 10-90 minutes, and preferably the standing time being 20-60 minutes; (4) performing a flash evaporation treatment on the coarse coal water slurry which has been left to stand; and (5) obtaining the coal water slurry with an increased concentration by filtering the coarse coal water slurry which has been subjected to the flash evaporation treatment, adding an additive and stirring the mixture successively.