Aspects of Very Fine Grinding

Experimental investigations of single particle and interparticle breakage show that the microprocess in mills demands an energy input between 1 J/g and 10 J/g, if particles below 100 pm have to be comminuted. A system analysis of grinding media and roller mills is given in respect to the energy supply to the microprocess and the influence of the back stream caused by the compression of the material inside the active volume. The back stream diminishes the probability for capturing the particles in very fine grinding processes. Some possibilities are discussed how to solve this problem.