In industry, crushers are machines which use a metalsurface to break or compress materials. Mining operations use crushers,commonly classified by the degree to which they fragment the starting material,with primary and secondary crushers handling coarse materials, and tertiary andquaternary crushers reducing ore particles to finer gradations. Each crusher isdesigned to work with a certain maximum size of raw material, and oftendelivers its output to a screening machine which sorts and directs the productfor further processing. Typically, crushing stages are followed by Millingstages if the materials need to be further reduced. Crushers are used to reduceparticle size enough so that the material can be processed into finer particlesin a Mill. A typical circuit at a mine might consist of a crusher followedby a SAG Mill followed by a ball Mill. In this context, the SAG Mill and ballMill are considered Mills rather than crushers.

In operation, the raw material (of various sizes) isusually delivered to the primary crusher’s hopper by dump trucks, excavators orwheeled front-end loaders. A feeder device such as an apron feeder, conveyor orvibrating grid controls the rate at which this material enters the crusher, andoften contains a preliminary screening device which allows smaller material tobypass the crusher itself, thus improving efficiency. Primary crushing reducesthe large pieces to a size which can be handled by the downstream machinery.

Some crushers are mobile and can crush rocks (as large as60 inches). Primarily used in-pit at the mine face these units are able to movewith the large infeed machines (mainly shovels)to increase the tonnageproduced. In a mobile road operation, these crushed rocks are directly combinedwith concrete and asphalt which are then deposited on to a road surface. Thisremoves the need for hauling over-sized material to a stationary crusher andthen back to the road surface.

Founded in 1997,Liming Group is a crusher and sand making machine manufacturer with a completeline of crushing, grinding and screening equipment. Our equipment can be usedin the mining, building materials, metallurgy, transportation, coal, chemicaland environmental protection industries.