crusher, machine used to reduce materials such as ore, coal, stone, and slag to particle sizes that are convenient for their intended uses. Crushers operate by slowly applying a large force to the material to be reduced. Generally this is accomplished by catching it between jaws or rollers that move or turn together with great force. Reduction in size is generally accomplished in several stages, as there are practical limitations on the ratio of size reduction through a single stage.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.