Vertical impact sand making machine is mostly used in the sand making industry, but most of the companies that produce this equipment are mining machinery manufacturers, so the requirements for sand and gravel are as follows:
1. Mining equipment requires fine particles for crushed materials. Generally speaking, the requirements for needle flakes are not strict, on the contrary, needle-like materials enter the mill and are more likely to be ground. The requirements of crushed stone are contrary to the above, and the requirements for its particle shape and particle size are very strict, and the reason is that cubic sand is the best aggregate for concrete and asphalt. Machine-made sand not only improves the strength of concrete, but also reduces the amount of cement, thereby reducing the cost, and secondly, the cubic sand has a mutual locking effect between the particles due to the edges and corners. The continuous gradation of sand can greatly reduce the void. At the same time, cubic sand occupies a larger surface area than round sand, so that asphalt and materials or cement and materials have the possibility of sticking together to reduce displacement;
2. According to the definition of machine-made sand, rock particles with a particle size of less than 4.75mm made by mechanical crushing and screening after soil removal treatment. However, it does not contain the particles of soft rock, weathered rock;
3. The specifications of sand are divided into three types: coarse, medium and fine according to the fineness modulus. Among them, the fineness modulus of coarse sand is 3.7~3.1, the fineness modulus of medium sand is 3.0~3.3, and the fineness modulus of fine sand is 2.2~1.6.
Fourth, the grade of sand is divided into three grades according to its technical requirements: I, II. AND II. Class I sand is suitable for concrete with a strength class greater than C60. II. Class sand is suitable for concrete and hydraulic concrete with strength grade C30~C60 and frost resistance, impermeability resistance or other requirements. II. Class sand is suitable for concrete and construction mortar with a strength grade less than C30; earth and building sand springs
5. The particle size of sand is between 4.75~0.15mm, and the stone powder less than 0.075mm should have certain restrictions, and its particle size is divided into 4.75, 2.36, 1.18, 0.60, 30, 0.15, it is best to be continuous, and each particle size should have a certain percentage, and its particle shape should be preferably a cube, and there are certain requirements for the amount of needles;
6. The rocks used for sand making generally include granite, basalt, natural river pebbles, andesite, rhyolite, diabase, diorite, sandstone, limestone, etc. The sand made of it has different strengths and different requirements depending on the type of rock.