Jaw crushers are size reduction tools that use a combination of gravity and crushing jaws to pulverize materials. Jaw crushers are so named because of their jaw-like configuration. They are important parts in a wide variety of industrial processes. Just a few of these processes include rock crushing in mining operations, trash compacting in waste management and recycling facilities, materials management and disposal during construction or demolition projects.
Industrial processes that require jaw crushers and utilize them include the size reduction and disposal of waste products and the refinement of raw mineral materials. Pulverizer manufacturers have responded to the diverse materials reduction needs of industry with a wide variety of pulverizing and crushing equipment.
These products range in size and operating capacity from small ball mills to impact crushers that occupy entire rooms. Jaw crushers range in terms of their size and operating capacity, but as a rule they fall somewhere in the middle of the full range of crusher sizes. In some cases they can be made portable, as is the case in some mining jaw crushers. Usually they are about the size of a storage shed.
A jaw crusher functions by the movement of a retractable plate toward and away from a stationary plate. The plates are set at an angle inside of a vertical channel. When material to be crushed is loaded onto the channel, the movable plate moves back and forth, crushing the objects as it moves forward and releasing crushed objects down out of the channel as it retracts.
Because the plates are positioned at an angle, jaw crushing is a multi-phase crushing process. Large materials are partially crushed at the top of the vertical channel, and they move lower as they are broken apart. By its nature, jaw crushing is a somewhat imprecise crushing process and cannot generate the fine-grained crushed objects that other crushing processes can.
For example, hammermills and grinding mills involve turning crushing tools that crush and grind objects over and over until they become small, granulated particles. However, jaw crushing is often not used for processing very small materials. If properly paired with an application, jaw crushing can be a valuable and efficient crushing method.