An Introduction To Stone Crushers

By Author: Qiao JingLiang
Total Articles: 4762
Comment this article

Stone crushers are used extensively in mining and various other industrial applications. As the name implies, stone crushers are machines that crush rock and stones as part of the mining or other industrial process. The process involves using extremely high pressure and forces to reduce the size of rocks so they are more manageable and can be more easily processed or transported. There are several types of crushers that are used in different applications but the basic principle is the same.

Early Stone Crushers

Although not quite mechanical, the earliest stone crushers were simply rocks held in people's hands, used to crush materials such as grains. The weight of the rock added to the force being applied and hence crushed the substances more effectively. Larger mortars and querns are examples of early crushing devices. With the Industrial Revolution, machinery evolved in leaps and bounds. The hard and resistant properties of steel proved very useful when inventors where looking for ways to mechanize processes. It's presumed that the first type of mechanical stone crusher was similar to a jaw crusher. This works ...
... off the basic principle of two plates working at an angle to one another. As the two plates are brought together, the force is sufficient to crush the rock into smaller particles.

How a Jaw Crusher Works

A jaw crusher has one steel plate that is in a vertical stationary position at an angle. The second steel plate lies at a convex angle to the first and is the flexible arm of the crusher. The arm is generally attached to a weighted flywheel which rotates and moves the jaw plate open and closed. The wheel is driven by a belt and machinery. Because the two arms of the crusher are positioned in a V-shape, a single force is not required to crush the rock. Rather it is the continual crushing motion and the repetitive crushing forces that refine the rock to the required smaller size. As the rock enters the crusher, it is broken down until it is small enough to fall through the bottom of the crusher. Jaw crushers can be used to crush very hard types of rock.

Other Types of Stone Crushers

In recent years, cone and gyratory crushers are becoming more widely used in mining applications. They work on a similar principle from that of jaw crushers. However, cone and gyratory crushers are sometimes believed to be more cost effective to operate because they make use of a circular motion rather than a backwards-and-forwards motion; therefore, they can provide greater output. A cone crusher is generally made up of two differently sized cones fitted inside each other. The inner cone rotates, forcing the rock again the outer mantle. As the rock enters the crusher, the largest pieces are crushed when forced between the two cones. The rock pieces then fall lower down the cone where they are crushed once again. This process is repeated until the rock pieces are small enough to fall out of the bottom of the crusher. Cone and gyratory crushers are very similar in design and operate off the same basic principle of using a circular motion to crush the rock. They can be used to crush medium to very hard types of rock.

Impact crushers are used for softer materials such as coal or waste material that needs to be recycled. There are two basic designs - horizontal shaft impactors and vertical shaft impactors. Horizontal shaft impactors are sometimes also called hammer crushers. The design principle uses small hammers that rotate on a spindle to crush rock that is poured into the crusher. Vertical shaft impactors use velocity as opposed to surface force to crush the rock. A high-speed rotor flings the stone against the outer chamber and this force is what breaks the rock into smaller pieces.

Modern Progress in Stone Crusher Designs

In recent decades, the designs have not changed fundamentally. What has been seen is greater optimization and customization of designs for a wider variety of applications. Crushers are now designed for a specific purpose and customized according to the type of rock they are required to crush. A strong focus on efficiency has resulted in crushers being adapted into mobile units. A great advantage of mobile units is that they can process raw materials on site. This reduces cost by eliminating the need for transportation of bulky ore. It also paves the way for small scale exploratory mining processes so that mining companies can establish the feasibility of mining a particular site before having to set up an expensive mining infrastructure.
About Author:
For heavy equipment such as jaw crushers, visit Crusher-Mills.com online where they supply efficient equipment and the latest technology.