A rock crusher breaks larger rocks or concrete down into cobblestones, gravel, or other smaller pieces. Those smaller pieces are sorted by size so they can be used for pavement, construction, and other uses.

There are two types of authorizations for a rock crushing plant. Large plants are authorized by New Source Review (NSR) permits while smaller plants are authorized by a Standard Permit, which limits the size and operation of the rock crushing plant.

We receive the most questions about smaller plants. A typical crusher authorized by this Standard Permit might have these components:

a primary crusher, to break large rocks into chunks

a secondary crusher, to break those chunks down into smaller pieces

two screening units, to separate the crushed rock by size

conveyors to carry materials from stockpiles to the crushers

stockpiles of rock and crushed rock

diesel-powered generators

Concrete crushers are similar to rock crushers but are built specifically to deal with slabs of broken pavement and other types of concrete.