Basic sand: It is the raw sand made of natural silica sand by washing and grading, and its silt content (mass fraction) is ≤ 1.0%. Sand washing is to send natural sand into a sand washing machine for cleaning, and the finished product after cleaning is natural sand. Through the washing process, the granularity of the finished product can be effectively standardized, and the granularity of the finished product can be combined and separated according to the needs of users.
River sand: Generally speaking, it refers to natural sand existing in rivers. It is a nonmetallic ore with complex composition, smooth surface and high impurity content, which is formed by repeated collision and friction of natural quartz stone under the action of running water for a long time. River sand particles are generally smooth, clean and widely available.
Machine-made sand refers to sand processed by sand making machine and other auxiliary equipment. Through vibrating feeder, jaw crusher, sand maker, vibrating screen, sand washer, dust collector, powder separator, belt conveyor, sand powder separator, electric control system, etc. All kinds of rock particles with feed granularity below 50mm can be processed and molded to obtain crushed stone and machine-made sand that meet the requirements and related quality requirements.
The finished products of machine-made sand are relatively regular, and can be processed into sand with different rules and sizes according to different technological requirements, which can better meet the needs of building sand.
And it is cleaned with a stone cleaning machine produced by Yongcan Machinery. Because artificial sand is a hand-picked raw material, its material is uniform and stable, and its mineral composition and chemical composition are consistent with those of raw materials, which is not as complicated as natural sand. In addition, the artificial sand produced by it is clean, free of mud and other harmful impurities, and has the advantages of stable performance and good particle size.
Sand is generally divided into natural sand and artificial sand. Rock particles with a particle size less than 5mm formed under natural conditions (mainly rock weathering) are called natural sand. Artificial sand is made by crushing rocks, but it is generally not used because of its high cost and many flakes and powders.
Natural sand can be divided into river sand, sea sand and mountain sand according to its source. Mountain sand has rough surface, angular particles, high sediment concentration, many organic impurities and poor quality. The surface of sea sand and river sand is smooth, but the salt content of sea sand is high, which has certain influence on concrete and mortar. River sand is clean and has a wide range of uses.
If the sand is of the same thickness, the gap is the largest, and the gap decreases when the sand with two particle sizes is matched, and the gap decreases when the sand with three particle sizes is matched. It can be seen that the porosity of sand depends on the matching degree of sand particle size at all levels.
Graded sand can not only save cement, but also improve the compactness and strength of concrete and mortar. The thickness of sand is expressed by fineness modulus Mx. The greater the fineness modulus, the coarser the sand. According to the range of fineness modulus, sand is divided into coarse sand, medium sand, fine sand and extra-fine sand.