A fine-coal dewatering machine that consists of a tank or truncated conical shell, which is revolved at the desired speed by means of a drive sheave. A screw conveyor rotates inside the cone or bowl at a slightly lower speed in the same direction of rotation. The feed entrance, in the center of the large end of the truncated cone, is high enough to allow formation of a pool of slurry. Adjustable effluent-discharge parts are so located in the large end of the bowl that the level of liquid is maintained at the desired height. The solids are steadily moved forward by the screw conveyor as fast as they are deposited, being carried above the level of the pool for an interval before leaving the bowl. Discharge of both solids and effluent is continuous.