Method for the operation of a stirring ball mill and a stirring ball mill for the practice of the method

A stirring ball mill comprising

• a barrel having a generally cylindrical interior surface, the barrel having an inlet at its one end for input of a feed, an outlet means at its other end for withdrawal of a milled feed and gases, and first stirring means comprising annular outer disks on the interior surface of the barrel reaching radially inward and allowing for the passage of feed therearound;
• means for rotating the barrel at supercritical speed;
• and
• a rotatable stirring shaft within the barrel and concentric therewith, the stirring shaft having second stirring means thereon comprising inner disks concentric with the stirring shaft reaching radially outward therefrom, the inner disks having an outer radius less than that of the barrel leaving an annular space therebetween for passage of feed, and the inner disks having passage openings to allow for the passage therethrough of gases, the passage openings being situated such that when the barrel is rotated at supercritical speed so as to centrifuge the particles therein, the passage openings are within a space within the barrel free of centrifuged particles to allow for the free passage of gases therethrough to said outlet means;
• wherein the outer disks project between successive inner disks and the inner radius of the outer disks is less than the outer radius of the inner disks.