Method and apparatus for continuous pressure comminution of brittle grinding stock

A mechanism for the continuous pressure comminution of brittle grinding stock, which comprises in combination:

• a roll jaw crusher including a pair of driven rollers having a varying nip width therebetween with the rollers having a diameter greater than 750 mm,
• means for delivering to the nip a grinding stock in which a substantial portion thereof has a grain size larger than the width of the nip,
• means applying a force to said rollers obtaining a crushing force in the nip in excess of 2 tons per centimeter of roll length, and
• the diameters of the rolls, the spacing of the rolls, and the speed of the rolls being such that said stock entering the nip is subjected to unit grain comminution in that portion of the nip which is relatively wide and to product bed comminution where the nip has its smallest width.

A mechanism for the continuous pressure comminution of brittle grinding stock, which comprises in combination:

• a roll jaw crusher including a pair of driven rollers having a varying nip width therebetween with the rollers having a diameter greater than 750 mm,
• means for delivering to the nip a grinding stock in which a substantial portion thereof has a grain size larger than the width of the nip,
• means applying a force to said rollers obtaining a crushing force in the nip in excess of 2 tons per centimeter of roll length,
• the diameters of the rolls, the spacing of the rolls, and the speed of the rolls being such that said stock entering the nip is subjected to unit grain comminution in that portion of the nip which is relatively wide and to product bed comminution where the nip has its smallest width,
• a tube mill connected to receive delivery of comminuted stock for the roll jaw crusher,
• a sifter connected to receive delivery from the tube mill to produce a coarse fraction and a fine fraction, and
• a return line leading from the sifter delivering the coarse fraction to the roll jaw crusher for reprocessing.

A mechanism for the continuous pressure comminution of brittle grinding stock, which comprises in combination:

• a roll jaw jaw crusher including a pair of driven rollers having a varying nip width therebetween with the rollers having a diameter greater than 750 mm,
• means for delivering to the nip a grinding stock in which a substantial portion thereof has a grain size larger than the width of the nip,
• means applying a force to said rollers obtaining a crushing force in the nip in excess of 2 tons per centimeter of roll length,
• the diameters of the rolls, the spacing of the rolls, and the speed of the rolls being such that stock entering the nip is subjected to unit grain comminution in that portion of the nip which is relatively wide and to product bed comminution where the nip has its smallest width,
• a tube mill connected to receive delivery of comminuted stock from the roll jaw crusher,
• a sifter connected to receive delivery from the tube mill, said sifter producing a fine fraction and a coarse fraction, and
• a return line connected from the sifter to an intake for the tube mill for returning coarse fraction material to be reprocessed by the tube mill.

A mechanism for the continuous pressure comminution of brittle stock, which comprises in combination:

• a roll jaw crusher including a pair of driven rollers having a varying nip width therebetween with the rollers having a diameter greater than 750 mm,
• means for delivering to the nip a grinding stock in which a substantial portion thereof has a grain size larger than the width of the nip,
• means supplying a force to said rollers obtaining a crushing force in the nip in excess of 2 tons per centimeter of roll length,
• the diameters of the rolls, the spacing of the rolls, and the speed of the rolls being such that said stock entering the nip is subjected to unit grain comminution in that portion of the nip which is relatively wide and to product bed comminution where the nip has its smallest width,
• a sifter connected to receive the delivery from the roll jaw crusher, such sifter producing a fine fraction and a coarse fraction, and
• a conduit leading from the discharge of the sifter back to an intake for the roll jaw crusher for delivering coarse fraction material for reprocessing by the roll jaw crusher.