In addition to agglomeration, separation and mixing, comminution is one of the four basic operations in mechanical process engineering.

Comminution usually means the splitting of a solid structure under the action of mechanical energy. Such comminution processes can be differentiated into real grinding or comminution, deagglomeration or desaggregation. However, emulsification, i.e. the splitting of liquid droplets or gas bubbles in another liquid, or even processes in which cell disruption is the goal, can also be understood as comminution processes.

The mechanical energy acts on the regrind in the form of compression, impact or shear stress or cutting stress. The mechanical energy can be transferred to the material to be ground by two tools, only one tool or, in this special case, by particle to particle collision.