In the concentrator, the vibrating screen is one of the commonly used classification equipment, and its screening effect is of great significance to the follow-up operation. In the use process, how to improve the screening effect of vibrating screen is a problem that needs to be considered. There are many factors that affect the screening effect of mine vibrating screen, among which three important factors are the characteristics of the materials entering the screen, the screen surface parameters of the vibrating screen, and the motion parameters of the vibrating screen.
Different materials have their own characteristics, such as density, hardness, water content and so on. Generally speaking, the screening effect of materials with higher hardness and better brittleness is better than that of materials with low hardness and poor brittleness. There are two aspects that can directly affect the screening effect for the screened materials: material size and moisture content. When the particle size of the material is close to the size of the sieve hole, the screening efficiency will be significantly reduced. This situation can be improved by increasing the amplitude of the vibrating screen. The increase of the amplitude can promote the fine material to pass through the screen surface and reduce the blocking phenomenon. When the material moisture content is large, the material is easy to produce adhesion, which reduces the screening efficiency. At this time, the sieving effect can be improved by increasing the mesh size.
The screen surface parameters of the vibrating screen include the shape of the screen hole, the opening rate of the screen surface, the material of the screen surface and so on. Generally speaking, the long screen surface has a long residence time of materials, more screening opportunities and high efficiency, while the processing capacity of wide screen surface is better. It has been proved that the optimum ratio of length to width of screen surface is 2:1 ~ 3:1. When selecting the screen surface of vibrating screen, different materials and its opening rate should be considered comprehensively.
There are two factors in the motion parameters of vibrating screen: vibration frequency and direction angle. For the material with large particle size, the higher the general frequency is, the higher the bounce times on the screen surface are, the more contact opportunities between the material and the screen surface are, and the occurrence of screen hole blockage is reduced. Therefore, properly increasing the vibration frequency can effectively improve the screening effect. The vibration direction angle is the angle between the vibration direction line and the screen surface. Generally, the direction angle of the linear vibrating screen is between 30 degrees and 60 degrees, while that of the circular vibrating screen is 90 degrees.
After the above analysis, we understand some factors that affect the screening effect of the mine vibrating screen and how to improve the efficiency of the vibrating screen. In a word, we should select the vibrating screen according to the actual needs, select the appropriate screen surface material as far as possible, improve the motor to adjust the excitation force, and try to ensure the lower moisture content of the material, so as to improve the screening effect on the premise of ensuring the processing capacity.