Crushers for crushing minerals such as coal, slag, gypsum and etc … is used to produce raw materials. Crusher gradually turns rocks into smaller particles using a very powerful initial force. In general, this is done by inserting rocks between the jaws or the rollers that move with a lot of force and rotate very fast. Reducing size generally occurs in several steps because there is a practical limitation to this action through a single step.
Figure 1 shows the function of the crushers: jaw crusher, cone crusher for primary and secondary crushing, roll crusher, hammer crushers, toothed and rotary for secondary crushing.
In the jaw crusher, the material is crushed by pressure, impact, bending, and sometimes with abrasion between the two shoulders of the main jaw which are in the form of a rectangle. The first shoulder is usually fixed and the second shoulder is the movable. When the shoulder moves, the crushed material is removed from the lower shoulder
The jaw crushers were developed in 1858 in the United States and cone crushers were constructed in 1877 .
In cone crushers, the stones are crushed in a conical area, which is one of the conic constituents and the other is movable, by a lanyard, and when the two cones are dispersed, the material enters the enclosure and as it approaches two cones of abrasion and grinding are created. The crusher is pulled to the bottom for the initial crushing of the conical bowl and the material it enters the Concave and Mental area, and as the two cones are approached, it’s done .
Cone crushers developed as secondary crushing in industries in the 1920s .
Hammer crushers or hammer mills hit the anti-wear plates with hammer drills rotating on a rotor at a fast speed, this type of crusher was proposed by Williams in 1895 .
Jaw crusher and cone crushers are used for crushing hard materials such as iron ore and building stone, and hammer crushers are used for soft materials such as coal, limestone, gypsum and so on .