METHOD OF AND APPARATUS FOR FINE, VERY FINE, AND MICROFINE COMMINUTION OF MATERIALS HAVING BRITTLE BEHAVIOR

摘要

2102215 9219379 PCTABS00017 Brittle material (1) is ground batchwise as a bed of particles by compression between non-yielding hard surfaces at a pressure of at least 50 MPa. In order to reduce the energy requirement and machine expenditure needed for fine, superfine and microfine comminution the bed of particles is subjected to repeated stressing by pistons (4) in different directions and at least in part successively. The stressing preferably is accomplished by groups of two opposed pistons (4) which are offset at an angle with respect to each other and which are rendered active one after the other. The stressing is repeated in another plane of the grinding chamber. Wet grinding is carried out in a closed grinding chamber from which the liquid expelled from the voids between the particles being ground can drain through at least one aperture of narrow cross section.