Abstract: A grinder constituted by a ring (10) having a horizontal axis, a mechanism for driving the ring in rotation about its axis, at least one roller (16) the axis of which is parallel to that of the ring and which is placed inside the latter so as to be able to travel over its internal surface and elastic member (30) for pressing the roller against the ring, the roller being supported at its ends by two arms (22) mounted on the frame of the grinder so as to be able to pivot about an axis parallel to the axis of the ring.

Abstract: A grinding apparatus for forward feeding material in a drum in which the grinding apparatus has a circular grinding track therein. The drum is driven in rotation at a speed such that material therein is held on the circular grinding track by centrifugal force. A knife is positioned in an upper descending portion of the drum for detaching material from the circular grinding track. A deflecting plate is disposed beneath the knife so as to receive materials detached by the knife and to divert the detached materials toward the output of the drum. The knife is disposed such that the knife has an active face forming an angle of between +15° and −50° with a radial plane extending between a horizontal axis of the drum and an edge of the active face.

Abstract: A grinder having an annular track with a horizontal axis (14), a roller (16) capable of travelling over the track, a mechanism for pressing the roller against the track and means (18) for displacing the material from one edge of the track to the other in such a way that it passes several times beneath the roller before being evacuated. To enhance the efficiency of the grinder and the distribution of mechanical stresses in the roller and the track, the track (14) and the roller (16) are designed in such a way that the gap between them decreases from the edge of the track (14) located on the side for supplying the material to be ground to a distance from this edge at least equal to 80% of the width of the track, and in that this interval then swiftly increases to form a decompression area (19) on the ground material evacuation side.

Abstract: A crusher comprises a cylindrical body, a lining supported by a portion of the cylindrical body and forming an annular track, the supporting cylindrical body portion having a prismatic interior surface, and at least one roller arranged to roll on the annular track. The lining consists of plates having a concave interior surface shaped to form a rolling surface of the annular track and a flat exterior surface resting on the prismatic interior surface of the supporting cylindrical body portion. This reduces the risk of breakage of the lining plates under the pressure applied thereto by the roller.

Abstract: An apparatus for milling particulate mineral material comprises two cylinders rotatable in opposite directions about parallel axes defining a plane while being yieldingly pressed towards each other, the cylinders defining therebetween a milling compression space having an inlet for the particulate material above the plane and an outlet for the milled material below the plane. To reduce the formation of agglomerates and prevent circumferential and/or lateral flushing of the material, the outlet space is closed by respective lateral flanges at the opposite cylinder end faces and a barrier including a scraping bar extending across the outlet space below the plane into contact with the flanges and having one edge in contact with the peripheral surface of one of the cylinders while an opposite edge defines a milled material output of reduced cross sectional area with the peripheral surface of the other cylinder.