Abstract: 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.

Abstract: A crusher with opposed jaw members that relatively reciprocate in a substantially linear path to crush material. The jaw members have stepped cruching faces, and a step in a crushing face is defined by a crushing expanse delineated by the front surfaces of spaced bars in a grid assembly. Pivoted arms may be employed to mount a movable jaw member.

Abstract: A device for crushing, pulverizing, classifying and dedusting dry grind or dewatering wet grind ores. The ore is fed into a trough in which is seated crusher, spacer and pulverizer bars vibrated by an electromagnet energized by a low frequency electric pulse generator. The ore, receiving repeated blows as it is vibrated between the bars and the bottom floor of the trough, is reduced in size and moved along the trough for classifying and dedusting dry grind or classifying and dewatering wet grind.

Abstract: A two-piece container and grinder combination is disclosed. The container has an upwardly projecting cylindrical post having outwardly extending grinding teeth. The cap is adapted to fit rotatably to the container and has two sets of teeth which cooperate with the teeth on the cylindrical post to grind the ingredients from the container as the ingredients pass from the container between the teeth.

Abstract: A plurality of rigid first comminuting elements are located in a container for material to be comminuted, and are stationarily mounted with reference to the container. A plurality of second comminuting elements are also located in the container and each of these confronts at least one of the first elements with spacing from the same. Resiliently yieldable springs mount each of the second elements for swinging movements relative to the first elements, so as to crush material in the gap by cooperation between the first and second elements. A drive is provided for imparting vibratory swinging movements to the second elements.