Abstract: A crushing device includes a casing with an inner wall, a rotor having a vertical axis of rotation, mounted in the casing and formed by a disk having a working surface with radially arranged fractionating blades mounted thereon and each including a working lateral face and a lateral face opposite to said working lateral face and each consisting of a main portion rigidly secured relative to the rotor disk and located nearer to the rotor axis and a peripheral portion pivoted to the rotor disk, rotatably mounted about the vertical axis, and having a section radially extending beyond said disk, and stationary grinding elements placed on the inner wall of the casing and arranged coaxially with the rotor disk.