1. Crusher is a device that applies mechanical force to solid materials to overcome the cohesion of materials and break them into small pieces. 2. Commonly used types of crushing machinery are: jaw crusher, cone crusher, rotary crusher, hammer crusher, roller crusher, etc. 3. Due to the difference in structure and function. The application scope of various types of crushers is: jaw crusher and cone crusher are suitable for crushing very hard rock blocks (compressive strength is150-250 MPa); Rotary crusher is suitable for crushing hard (compressive strength 100MPA or above) and medium hardness (compressive strength 100MPA or so) rocks. Hammer crusher is suitable for crushing brittle rocks with medium hardness (the ultimate compressive strength is below 100MPA); Roller crusher is suitable for crushing ductile rocks with medium hardness (the ultimate compressive strength is about 70MPA). In the actual selection, the following factors should also be considered according to the specific situation: 1, the physical properties of the material, such as brittleness, viscosity, moisture and mud content, and the maximum feeding particle size; 2, the total output and finished product classification requirements, so as to choose the crusher type and production capacity; 3, technical and economic indicators, to ensure the quality and quantity, convenient operation, reliable work, to maximize cost savings. The main crushing functions of various crushers and mills are: 1, jaw crusher, cone crusher, roller crusher, etc. , with extrusion as the main function; 2, hammer crusher and impact crusher, etc. , mainly with the impact effect; 3, wheel mill and roller mill, etc. , mainly squeezing and grinding; 4, ball mill, rod mill, vibration mill and jet mill, etc. , mainly grinding and impact. Generally speaking, jaw crusher, cone crusher, etc. Used for coarse crushing, cone crusher, hammer crusher, impact crusher, etc. Used for medium crushing, roller crusher, etc. Used for fine grinding, ball mill, vibration mill and jet mill are used for grinding. But this is not absolute. Some machines are suitable for both coarse and medium crushing. Want to buy a crusher, recommend a best crusher manufacturer in Henan, the company website: www.lmlq.com, and this company also has a beautifully made video clip: /ver3.0/video/