The rotational speed of the drum of an ore mill may be controlled variably over time. By rotating the drum during a first time interval at high speed, especially hard or dense particles are broken up by tumbling. At the same time, the discharge characteristics of the mill are adversely affected. In a subsequent second time interval, the drum is rotated at a slower speed, and the material is discharged more effectively, whereas the tumbling movement inside the mill is not achieved. The combination of said different modes of operation within short time periods in continuous operation may improve both the comminution as a result of a tumbling motion of the material and also the discharge of the ground material. By regulating the rotational speed with different target values within short time windows, different requirements for the movement behavior of the material to be ground and for the discharge characteristics of the ground material can be simultaneously optimized. This may allow a higher throughput for the mill.