The production of sand and gravel aggregates is mainly divided into several links: mining, crushing, screening, and forming, generally according to raw material characteristics, system scale, site layout conditions, system technology, etc.
The main equipment includes crushers, vibrating screens, sand-making machines, and auxiliary equipment such as belt conveyors, feeders, stone powder recovery equipment, water supply equipment, and dust collectors.
According to the working principle of crushing equipment, it can be divided into two categories:
1. A kind of extrusion crushing equipment, such as jaw crusher, cone crusher, etc., suitable for crushing raw materials with high wear index. The content of stone powder in the product is low, but there are many needle-like particles in the crushed material, and the suction performance is poor.
2. One is impact crushing equipment, such as impact crusher, hammer crusher, and impact crusher, which is characterized by large material crushing ratio, simple structure, convenient equipment maintenance, good particle shape, and low material compressive strength loss.
On the large-scale sand and gravel production line, jaw crushers are usually used for coarse crushing, and for medium crushing, cone crushers, impact crushers, or hammer crushers are used.
The commonly used crushers for sand and gravel aggregate production lines and their advantages, disadvantages, and scope of application are as follows:
1. Jaw crusher
It has the characteristics of crushing ratio, uniform particle size, simple structure, reliable work, easy maintenance, and economical operating costs. It is widely used in mining, smelting, building materials, highways, railways, water conservancy, and chemical industries, etc., to crush various materials with a compressive strength of not more than 350 MPa.
Advantages: simple structure, reliable operation, small size, lightweight, low configuration height, large feed port, flow adjustable quantity, low price;
Disadvantages: the inner lining wears quickly, the product grain shape is not good, the needle plate has many shapes, the output is low, and the need is strong system feed;
Scope of application: Rock hardness has good adaptability, is generally used for coarse crushing of raw materials, and is used in medium crushing equipment. Need to be miniaturized.
2. Cone crusher
Widely used in mines, cement plants, sand and gravel industries, for medium and fine crushing of various mine rocks with pressure below 360 MPa, such as iron ore, non-ferrous metal ore, basalt, granite, limestone, sandstone, Pebbles, etc.
Advantages: reliable operation, high yield, uniform particle size, and small wear of the inner lining;
Disadvantages: complex structure, high maintenance requirements, large installation scale, high price;
Scope of application: The rock hardness has good adaptability, the most commonly used medium, and fine crushing equipment on the aggregate production line.
Impact Crushers HSI And VSI copy
3. Impact Crusher
It has the characteristics of a large crushing ratio, high crushing efficiency, cubic product shape, and selective crushing. It can handle various materials with a particle size of no more than 500 mm and a flexural strength of no more than 320 trillion pieces. It is ideal aggregate processing equipment for highway and hydropower construction, as well as airports, construction, and other industries.
Advantages: large crushing ratio, fine product, good grain shape, low energy consumption, simple structure;
Disadvantages: The steel hammer and gasket are easy to wear, the replacement and maintenance workload is large, and the dust is serious. It is not suitable for broken plastic and viscous materials;
Scope of application: suitable for crushing medium-hard rock, medium crushing, and sand-making equipment. There is also some large-scale equipment used for coarse crushing.
4. Hammer crusher
It is suitable for crushing minerals of various brittle materials. The crushed materials are coal, salt, white Asia, gypsum, alum, bricks, tiles, limestone, etc. The compressive strength of the material is not more than 100 MPa, and the humidity is not more than 15. It has the characteristics of a simple structure, large crushing ratio, high production efficiency, etc. The equipment can adjust the gap between the grate bars and change the discharge particle size according to user requirements to meet the different needs of different users.
Advantages: large crushing ratio, high yield, good grain shape, fine material;
Disadvantages: the hammer is damaged quickly, and replaced frequently, the working dust is large, the moisture content of the raw material exceeds 12%, and the rubber cannot be effectively passed;
Scope of application: suitable for crushing medium-hard rock, generally used for fine crushing equipment; when there is a great, it is used for sand making, and it is rarely used at present.
The choice of each type of equipment in the sand and gravel production line affects the quality of the finished product.
Full consideration should be given to the material properties and gradation of the finished materials.