The ultrafine vertical mill will cause "belly swelling", that is, overload. At this time, the sound of the ultrafine vertical mill is dull and weak, and the grinding function will be lost.

At this time, the ore feeding shall be reduced or stopped immediately, the overflow concentration shall be increased, and the ore feeding shall be carried out after the mill returns to normal operation.

In addition, if the ore feeding is insufficient, the ultrafine vertical mill will have the situation that the ore discharge particle size will become finer and the return sand volume will be reduced.

When the ore feeding is significantly insufficient, the impact sound of lining plate and steel ball will occur, resulting in the useless consumption of grinding medium and lining plate.