Difficulty: Easy
Correct Answer: Compression
Explanation:
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
Discussion & Comments