The Gyratory disc crushers are a further development of the cone crusher for the application of crushing strong abrasive rocks to particle sizes of less than 2 or 3 mm to fall within the 'sand' specifications.
The cone crusher is modified such that the crushing chamber and head have a very low angle of inclination (25~ ) and the crushing faces are almost parallel. Rock passes through the machine slowly as a deep bed of particles transported by the movement of the cone surface. The gyratory action of the head causes this bed rather than individual particles to be repeatedly compressed between the mantle and concave and the production of fine particles by interparticulate breakage. Since the setting no longer directly controls the maximum size of particle in the product, the crusher is always operated in closed circuit with a screen.