In the process of beneficiation, the purpose of classification operation is to effectively separate the coarse and fine particles, avoid over crushing of fine minerals, and make the coarse minerals return to the mill as return sand for regrinding. Its operation effect will directly affect the production capacity of grinding equipment, finished product effect and concentrate grade and recovery in subsequent beneficiation. Fodamon Engineers mentioned that at present, spiral classifier and hydrocyclone are common classification equipment in two concentrators. Before deciding which grading equipment to use, we must know the difference between the two, and then make a targeted choice.
01. Applicable materials have different particle sizes
Common spiral classifier include high weir type and submerged type. Among them, high weir spiral classifier is usually used for coarse-grained classification, and its classification overflow particle size diameter is generally greater than 0.15mm. The submerged spiral classifier is suitable for fine particle classification, and the grading overflow particle size is generally less than 0.15mm. Compared with the two spiral classifiers, the hydrocyclone has better classification effect when dealing with fine-grained materials (the separation particle size range is generally 0.3-0.01mm).
02. Different classification efficiency
Generally, the classification efficiency and product accuracy of hydrocyclone are lower than those of spiral classifier. A large part of the reason is that hydrocyclone will change the final material discharge position when the pressure is not up to standard.
The spiral classifier rotates at a low speed through the spiral to stir the pulp, so that the fine particles are suspended above and overflow at the overflow weir, while the coarse particles sink to the bottom of the tank and are transported by the spiral to the discharge port for return discharge, while the hydrocyclone needs to be discharged on the side opposite the feed port. Once the pressure does not meet the standard, the stratification of materials will be disordered, resulting in the failure of normal discharge of materials from the discharge port. However, this is not absolute. When the classification particle size is very fine (such as 0.037mm), the classification efficiency of hydrocyclone is significantly higher than that of other classification equipment.
03. Different floor areas
Obviously, the floor area of hydrocyclone is significantly smaller than that of spiral classifier. Generally, the floor area of hydrocyclone is only 1 / 30-1 / 50 of that of spiral classifier. The requirement of equipment floor area limits the application of spiral classifier to a certain extent.
04. Different daily operation requirements
The spiral classifier has the advantages of simple structure, stable operation and easy operation. It is also its simple operation process and stable working state, which not only greatly reduces the maintenance and replacement cost, but also ensures the construction time and ensures the hierarchical operation. Relatively speaking, the operation of hydrocyclone is more complex, and the feed pressure, concentration and particle size will affect its classification index, so the accuracy of operation is required to be high.
05. Different equipment investment costs
In terms of equipment investment, the price of hydrocyclone is lower than that of spiral classifier. In addition to its own equipment, the hydraulic spinner also needs a series of necessary auxiliary equipment in the classification process, such as distributor, valve, pump, etc., which increases some equipment investment accordingly.
In terms of equipment maintenance, the wear parts of hydrocyclone are mainly lining and overflow pipe. The wear frequency and degree are caused by factors such as particle size, shape and solid content of materials. Therefore, only in the actual concentrator practice can we accurately obtain its service life and maintenance cost. The maintenance of spiral classifier is mainly to replace spiral lining and other daily maintenance.
The classifier equipment cooperates with the grinding equipment in the beneficiation machine production line to jointly provide ore (material) with appropriate particle size for beneficiation operation. The selection of any beneficiation equipment will not be decided unilaterally, but must be the result of comprehensive consideration. In production, it is recommended that you select single or multiple classification equipment according to the selection of relevant equipment given by beneficiation test, so as to achieve ideal classification effect.