Abstract: A method of and apparatus for breaking stone rock or other frangible material and separating fines from the resultant mixture, having a cyclonic breaking zone in a lower part of a housing in which a rotor operates to break up larger pieces, the action causing fines to rise in the housing for discharging from an upper region of the housing. Alternative positions for exits for the fines are in the wall or roof of the housing or in a shelf which extends outwardly beyond the wall confining the breaking zone.

Abstract: Mineral impact breaking apparatus uses a divided flow with the first part of the flow being accelerated preferably through a rotor and discharged towards an impact breaking surface. The second part of the mineral flow is introduced into the path of the accelerated first part of the flow so that there is impacting between the first and second flows of minerals and with the second flow acting as anvil blocks against which the first flow particles will be impacted and broken. Where the horizontal accelerating rotor is used to accelerate the first part of the mineral flow the kinetic energy of the rapidly rotating air above the rotor is used to direct an air flow back to the infeed of the rotor and minimize dust discharge.

Abstract: A rotary mineral breaker has wear tip over which the mineral pieces are passed when discharged from the rotor. A supplementary wear tip is provided as a back up for the main wear tip so that failure of the main wear tip will not result in undue damage occurring to the rotor. Also the main wear tip is provided as two interchangeable pieces to improve the useful life of the wear tip.

Abstract: A mineral breaker with a horizontally mounted driven accelerating rotor having a mineral inlet on the under surface thereof and with material to be processed being drawn into the rotor in a flow of air. The processed material is discharged also in a flow of air through a tube or tubes from the top of the rotor housing. Mineral pieces not sufficiently reduced in size may be recirculated through the rotor and additional material added for further processing. The size of processed particles is controlled by the airflow passing through the rotor.