In this training module, Performance Associates International (PAI) covers the characteristics of a gyratory crusher that’s designed to be the first stage in the size reduction of run-of-mine ore. A gyratory crusher receives ore from a mine and crushes the ore between a gyrating main shaft and stationary liners called concaves. This module explains the gyratory crusher’s principle of operation and provides detailed descriptions of the major components and the role that each component plays in its operation. You'll learn how the drive system operates, the details of the dust sealing system, the importance of the various lubrication systems, and the two functions of the main shaft positioning system, or MPS. We’ll also explain the operation of the balance cylinders and how they’re designed to prevent oversize boulders from causing damage. We’ll also cover the apron feeder, which conveys the crushed ore from the crusher to a downstream discharge conveyor belt. The principle of operation and detailed descriptions of the components of the apron feeder—including the drive chains, pans, rollers, and an electric or hydraulic motor—are illustrated. This is one of many plant area modules that is covered in a typical PAI operations training module.