PURPOSE: To obtain granulated coal of good quality efficiently by performing the entire process of granulation through plural granulating tanks and treating liquid to be treated in such a way that the concns. thereof increase when moving the liquid from a tank to a tank.

CONSTITUTION: The liquid 10 to be treated in the 1st granulating tank 2 overflows into a trough 18 by as much as the flow rate at which said liquid flows into said tank from the side of a valve regulating tank. Water 25 enters the inside of a fluid receiving tank 21 through screen meshes 20. Granulated coal 14a remains in the trough 18. The granulated coal in the trough 18 is fed into the 2nd granulating tank 3 on account of its inclination. since the flow rate of the water 25 discharged from the tank 21 is smaller than the flow rate at which said water enters the tank 21, the water 25 in the tank 21 overflows finally from a fluid overflowing outlet 22 into the tank 3. Thus the water 25 is again mixed with the coal 14a, and the liquid 10 having a concn. higher than the concn. in the tank 2 is obtained.