Abstract: A roller press for compacting fine-grained chemicals, especially salts, into sheets, having synchronously driven rollers with two axially spaced pressing surfaces on ring elements being provided with radial shoulders at both of their ends. Screw feeders for feeding the salt into the roll nip and wedge-shaped wall elements closing-off the roll nip in the axial direction on both ends of said ring elements and bearing against the shoulders, are also provided. Adjustment rods acting parallel to the roll axis are provided for the outer wall elements and vertical rods between the inner wall elements acting onto these wall elements via wedge-shaped surfaces arranged on said rods and the walls of said wall elements facing each other. The ring elements are integral with the roller bodies or separate cylindrical rings shrink-fit onto the roller bodies. Each ring element is associated with at least two screw feeders.

Abstract: A method and apparatus for continuous pressure comminution of brittle grinding stock such as cement clinker wherein simultaneous operations of unit grain comminution and product bed comminution are carried out in the roller gap of the same roller machine in such a manner that the grinding stock is first precomminuted by means of the unit grain comminution in a wider roller gap and immediately thereafter, the grinding stock fragments produced in the unit grain comminution are further comminuted by the technique of product bed comminution in the region of the narrowest roller gap. The continuous pressure comminution is characterized by a high pressure of more than 2 metric tons per centimeter of roller length, with a sifter being provided after the pressure roller.

Abstract: A roller crusher for receiving a harder to grind material, means mixing the harder to grind material with an easier to grind material and delivering the mixed materials to a ball mill for common grinding, separating the remaining coarse particles from material received by the grinder by a sieve or a cyclone, and recirculating the remaining the coarse particles to the ball mill.