First, the stone divided according to particle size and particle size
The particle size of the stone in the mining industry is usually between 5mm and 31.5mm, of which:
● 5-1 stone represents 5-10mm gravel;
● 1-2 stones represent 10-20mm gravel;
● 1-3 stone represents 16-31.5mm gravel;
● 2-4 stone stands for two or four points, the international standard is 1/4-1/2 inches, which means 10-15mm gravel;
● 4-6 stone stands for four or six points, the international standard is 1/2-3/4 inches, which means 15-20mm gravel. Because the size of the gravel is not uniform, it needs a range when using the vibrating screen for screening and grading. This 1-2, 1-3, 2-4 refers to this range, the unit is centimeters, that is, centimeters, such as 1 -2 is the small diameter of this batch of gravel is 1 cm, the large diameter is 2 cm, of course, this range refers to the vast majority, does not mean all.
Second, the sand divided according to particle size and particle size
Refer to the standard of construction sand in China: sand refers to rock fragments with a particle size of less than 5 mm and formed and accumulated in natural conditions such as lakes, seas, rivers and mountains. It can also be processed by mining machinery with a particle size of less than 4.75. Mm of construction particles.
The thickness of the sand is divided into 4 levels according to the fineness modulus:
Coarse sand: fineness modulus is 3.7-3.1, and average particle diameter is 0.5 mm or more.
Medium sand: fineness modulus is 3.0-2.3, and average particle size is 0.5-0.35 mm.
Fine sand: fineness modulus is 2.2-1.6, and average particle diameter is 0.35-0.25mm.
Extra fine sand: fineness modulus is 1.5-0.7, and average particle diameter is 0.25 mm or less.
Third, other specifications of sand and gravel
1. The length of the needle and flaky granular stone particles is greater than 2.4 times the average particle size of the granules of the granules; the thickness is less than 0.4 times the average particle diameter; the average particle size refers to the granule level. , the average of the lower particle diameters).
2, the amount of mud in the stone particles less than 75um particle content.
3. Mud content The original particle size of the gravel is greater than 4.75mm, which is less than 2.36mm after being washed by water and pinched.
4. Stone powder content Stone powder refers to rock particles with a particle size of less than 0.075 mm (75 microns).
5. Ruggedness Sandstone, especially the ability of stone to resist cracking under natural weathering and other external physical and chemical factors. In addition to the particle size and particle size specifications, there are corresponding requirements for the needle-like particles, mud content, mud content, stone powder content and firmness of sand and gravel in various industries. Therefore, it is necessary to specify requirements in advance when configuring the production line, so as not to affect Quality and sales of finished materials.
Contact: Kingsley Ma
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