Methods of stone crushing

With the development of science and technology, great progress has been made in the understanding of material crushing. A variety of different crushing methods are used for huge granular materials, and products of several microns can be obtained to meet various process requirements.

In the industry, the widely used material crushing method is still mechanical crushing, mainly including extrusion, chopping, breaking, grinding and impact crushing. Non-mechanical crushing has not yet been used in large-scale industrial production.

Under the action of external force, the stress generated by the material reaches the ultimate strength, and the material is broken immediately. There are several ways to apply force to crushing machinery.

A squash
Place the material between the two extrusion surfaces (Figure a). After applying force, the material will be broken due to its compressive stress reaching the limit of compressive strength. Jaw crushers and cone crushers are mainly using this method.

B Chopped
Place the material between a plane and a tooth (Figure b). When the extrusion force is applied, tensile stress is generated in the material. Because the tensile stress reaches the tensile strength limit, it splits along the direction of the force.

C Fracture
Place the material between two surfaces with teeth (Figure c). When the squeezing force is applied and the bending stress reaches the limit of the bending strength of the material, the material is broken.

D Impact
The crushed material is broken by the impact force of high-speed rotation (Figure d). This method can be implemented in a variety of ways. Since the force is applied instantaneously, the deformation is too late to extend to the various parts of the impacted object.

Considerable local stress is generated at the impact, which breaks along the internal micro-cracks. Therefore, the crushing effect of dynamic load is far greater than that of static load. Typical applications are hammer crushers and impact crushers.

E Grind
Place the material between two relatively moving working surfaces (Figure e), and apply pressure and shear force at the same time. When the shear stress generated in the material reaches its shear strength limit, the material is broken.

In fact, various crushers are the result of the combined effect of several crushing methods in the process of crushing materials. However, one or two ways of applying force must be the main one, and there must be other ways of breaking. Due to various

The physical and mechanical properties of materials are very different, so the force method of the crusher should be compatible with the mechanical properties of the materials in order to achieve a good crushing effect.