Device for mixing powdery, granular and/or pasty material, comprising a conical mixing vessel (1) having a vertical axis (2) that narrows downwardly, and at least one mixing screw (13) that extends parallel to the innerside of the mixing vessel (1) and at the one hand makes a rotating movement around its sloping axis (14) and at the other hand makes integrally a revolving movement parallel to the innerside of the mixing vessel (1), in which the drive unit (6) for the mixing screw (13) is provided with a vertical passage (15).
According to the invention the passage contains a rotating driveshaft (17) with at the lower end a horizontal, fast rotating rotor (18).
The rotor (18) with its driveshaft (17) is mounted in a cage which is open at the lower end, of which cage (19) the upper end is hung on the lower side of the central shaft (17) of the drive (6) unit that extends into the mixing vessel (1).
Preferably a separate driving motor for the rotor shaft (17) is mounted on the central drive unit.