Sand And Gravel Specifications
The size of stones in the mining industry is usually between 5mm and 31.mm, of which 5-1 stones represent 5-10mm gravel; 1-2 stones represent 10-20mm gravel; 1-3 stones represent 16-31.5mm gravel; 2-4 stones represent dichotomy, the international standard is 1/4-1/2 inch, representing 10-15mm gravel; 4-6 stones represent 46 minutes, the international standard is 1/2-3/4 inch, representing 15-20mm gravel.
Because the size of gravel is not uniform, we need a range when screening and grading with vibrating screen. The range of 1-2, 1-3, 2-4 refers to this range. The unit is centimeter, that is, centimeter. For example, 1-2 refers to the small diameter of the gravel is 1 centimeter, and the large diameter is 2 centimeters. Of course, this range refers to the vast majority, not all.
Sand refers to rock debris formed and accumulated in natural conditions such as lakes, seas, rivers and mountains with a diameter of less than 5 mm. It can also be a building particle with a diameter of less than 4.75 mm processed by mining machinery. The sand is divided into four grades according to fineness modulus.
- Coarse sand: Fineness modulus is 3.7-3.1, average particle size is more than 0.5mm.
- Medium sand: Fineness modulus is 3.0-2.3, average particle size is 0.5-0.35 mm.
- Fine sand: Fineness modulus is 2.2-1.6, average particle size is 0.35-0.25 mm.
- Ultra-fine sand: fineness modulus is 1.5-0.7, average particle size is less than 0.25 mm.