Mineral Processing Equipments: Crushers

Crushers reduce coarse material to a desired size. The crushing process uses mechanical energy and rubbing to fracture the rock. The forces applied to rock fragments during crushing processes are -
Compression force
Impact Force
Compression is a slow application of force on the rock while impact is a short, sudden application of force.

All crushers generate dust. Crushers that primarily use impact forces produce large amounts of fines and dust. Those that primarily use compression forces produce dust in proportion to the stage of reduction: dust production increases progressively from first- to third-stage crushing.

Types of Crushers

There are six main categories of crushers used in minerals processing operations:
Jaw crushers
Gyratory crushers
Cone crushers
Hammermills
Impact breakers
Roll crushers
Jaw, gyratory, and cone crushers primarily use compression forces; hammermills, impact breakers, and roll crushers use impact forces.

Article Sources:
http://www.osha.gov/SLTC/silicacrystalline/dust/chapter_2.html