Hydrocyclone Is the use of centrifugal force to speed up the sedimentation of ore classification equipment. It needs pressure feeding, so it consumes a lot of power, but it occupies a small area, has a low price, has a large processing capacity and high classification efficiency. It can obtain very fine overflow products, and is mostly used in the classification equipment of two-stage closed-circuit grinding.
Hydrocyclone is a kind of high efficiency classification and desliming equipment. It has been widely used at home and abroad because of its simple structure, easy manufacturing and large processing capacity. Its main disadvantages are large power consumption and serious wear during high-pressure ore feeding. New wear-resistant materials, such as hard alloy, silicon carbide, etc., are used to make the grit chamber and In addition, when used in the classification of closed-circuit grinding, because of its small volume, it has no buffering capacity to the fluctuation of ore volume, so it is not as stable as the mechanical classifier.
The lower part of the cylinder is composed of two hollow hydrocyclones. In addition, hydrocyclone also has feeding pipe, overflow pipe, overflow pipe and grit setting mouth.
Hydrocyclone uses sand pump (or elevation difference) to rotate pulp into cylinder along tangent direction at certain pressure (generally 0.5-2.5 kg / cm) and flow rate (about 5-12 M / s), and then slurry rotates along the cylinder wall at a very fast speed to produce centrifugal force. Under the action of centrifugal force and gravity, the coarse and heavy ore particles are thrown out.
Hydrocyclone is mainly used for classification, separation, concentration and desliming in mineral processing industry. When the hydrocyclone is used as classification equipment, it is mainly used to form a grinding classification system with the mill; when used as desliming equipment, it can be used for desliming in gravity concentration plant; when used as concentration and dewatering equipment, it can be used to concentrate the beneficiation tailings and then send them to fill the underground mining tunnel.
The hydrocyclone has no moving parts, simple structure, large production capacity per unit volume and small area, high classification efficiency (up to 80% - 90%), fine grading granularity, low cost and low material consumption.
(1) Feeding pressure: the feeding pressure is an important parameter of hydrocyclone. Increasing the feed pressure can increase the slurry flow rate, increase the centrifugal force on the material, and improve the classification efficiency and underflow concentration. However, the effect of reducing the classification particle size by increasing the pressure is very small, but the kinetic energy consumption is greatly increased, and the overall hydrocyclone, especially the underflow nozzle, is more seriously worn. Low pressure (0.05 ~ 0.1MPa) operation is used for coarse material treatment, and high pressure (0.1 ~ 0.3MPa) operation is used for fine and muddy materials.
(2) Feeding amount: the larger the feeding amount, the larger the grading granularity, and the smaller the feeding amount.
(3) Concentration: when the cyclone size and pressure are fixed, the feed concentration has an important impact on the overflow particle size and classification efficiency. When the feed concentration is high, the viscous resistance of the fluid increases, the grading particle size becomes coarse and the classification efficiency decreases. The practice shows that when the grading particle size is 0.074mm, the feed concentration is 10% ～ 20%.
(4) Feed size: the change of feed size will obviously affect the classification effect of hydrocyclone. When other parameters are constant, when the content of material smaller than grading size in feed is less, the content of fine particles in underflow is less and the concentration is high, while the content of coarse particles in overflow increases, the classification efficiency of hydrocyclone decreases; when there are more materials close to grading size in feed, there are more fine materials in underflow and more coarse materials in overflow, and the classification effect decreases.