In a gyratory crusher, what is the dominant mechanism by which rock is broken?

Introduction / Context:
Gyratory crushers and jaw crushers are principal compression machines for primary crushing of hard rock.

Concept / Approach:
In a gyratory crusher, a gyrating mantle inside a concave bowl compresses rock in a narrowing annular space. The material is crushed by nipping and compressive squeezing as it moves downward under gravity.

Why Other Options Are Wrong:
Impact is secondary in gyratories; primary impactors are separate machines.Attrition and cutting do not describe the core action in this device.

Final Answer:
Compression