Glass cullet of less than 6 mm in size produced by the glass crusher is further milled to produce galss powder. Our cullet mill is a tube mill modified for glass cullet. Its inlet can easily take in glass pieces of different sizes and shapes, and its outlet discharges glass powder in the order of smaller specific gravities. The produced glass powder is separated from paper, such as bottle labels, by a rotary sieve within the two-layer hopper. The cullet mill contains many alumina balls, which collide with each other to mill cullet. The machine requires no maintenance for about 2 years. The full-automatic operation of the cullet mill synchronized with the glass crusher enables a continuous production of glass powder, and has achieved a stable glass powder production of the specified grain size and a higher production efficiency (more than 97%).