A device for disintegration of argillaceous materials comprises a plurality of vanes 8 mounted on the inner surface of the housing 1 between the outlets of the feed pipes 2 and 3 and the inlets of the discharge pipes 4 and 5. Each of the vanes 8 is arranged in a manner such that the angle between the tangent 11 to the cylindrical surface 1 in the plane of the vane 8 and the plane 12 perpendicular to the axis 6 of the housing 1, is between 0 and 60 degrees. As the hydraulic fluid stream impinges upon the vanes 8, the argillaceous material is multiply exposed to pressure differentials and cavitation, this favoring faster impregnation of clay lumps with water and their disintegration leading to separation of mineral grams.