According to market demand, we can use mining machinery and equipment to crush large-size stones into stones or sands of different sizes to meet the different requirements of construction, railways, highways, highways, and other projects on sand and gravel materials. Understanding the specifications of the finished material can provide the necessary reference for the user to select the equipment.

1. Stones divided according to particle size and particle size

The particle size of the stones mentioned in the mining industry is usually between 5mm-31.5mm, of which:

5-1 stones represent 5-10mm crushed stones.

1-2 stones represent 10-20mm gravel.

1-3 stones represent 16-31.5mm gravel.

2-4 stones represent two or four points. The international standard is 1/4-1/2 inches, which means 10-15mm gravel.

4-6 stones represent four or six points. The international standard is 1/2-3/4 inch, which means 15-20mm gravel.

Because the size of the gravel is not uniform, it is necessary to use a vibrating screen for screening and classification. The 1-2, 1-3, 2-4 refer to this range, and the unit is cm, that is, centimeters, such as 1 -2 means that the smaller one is 1 cm in diameter and the larger one is 2 cm in diameter. Of course, this range refers to the vast majority, not all of them.

2. Sand according to particle size and particle size

Refer to the standard of construction sand: sand refers to the rock fragments formed and accumulated in natural conditions such as lakes, seas, rivers, mountains, etc., with a particle size of less than 5mm. It can also be processed by mining machinery with a particle size of less than 4.75mm Of building particles.

The thickness of sand is divided into 4 levels according to the modulus of fineness:

Coarse sand: the fineness modulus is 3.7-3.1, and the average particle size is 0.5mm or more.

Medium sand: fineness modulus is 3.0-2.3, average particle size is 0.5-0.35mm.

Fine sand: The fineness modulus is 2.2-1.6, and the average particle size is 0.35-0.25mm.

Extra-fine sand: The fineness modulus is 1.5-0.7, and the average particle size is below 0.25mm.

3. Other specifications of sand and gravel

1) Needle, flake particles

Stone particles whose length is greater than 2.4 times the average particle size of the particle size to which the particle belongs are needle-shaped particles; those whose thickness is less than 0.4 times the average particle size are flaky particles (the average particle size refers to the average of the upper and lower limits of the particle size) ).

2) Mud content

The content of particles with a particle size of less than 75um in the stone.

3) Mud content

The original particle size of the crushed stone is greater than 4.75mm, and the particle content is less than 2.36mm after being immersed in water and hand-kneaded.

4) Stone powder content

Stone powder refers to rock particles with a particle size of less than 0.075mm (75 microns).

5) Robustness

The ability of sand and gravel, especially stones, to resist cracking under the action of natural weathering and other external physical and chemical factors. In addition to particle size and particle size specifications, various industries also have corresponding requirements for the needle-like particles, mud content, mud content, stone powder content, and firmness of sand and gravel materials. Therefore, the requirements must be specified in advance when configuring the production line to avoid impacting The quality and marketability of finished materials.