Introduction of grading steel ball for ball millDate: 2019-07-11 Views:
The main function of steel ball in ball mill is to impact and break the material, and bring about certain grinding effect.Therefore, the purpose of grading steel balls is to meet the requirements of these two aspects.The quality of crushing effect directly affects the grinding efficiency and ultimately affects the output of the ball mill.Whether the crushing requirements can be achieved depends on whether the classification of steel balls is reasonable, including the size of steel balls, the number of ball diameters and balls of various specifications.Ratio, etc.In addition to the size of the ball mill, ball mill internal structure and product fineness requirements and other factors, but also should consider the parameters of grinding materials (wear resistance, particle size, etc.).
In order to effectively crush materials, several principles must be followed in determining grading:
First of all, the steel ball should have enough impact force to make the ball grinding ball have enough energy to crush the granular material, which is directly related to the maximum ball diameter of the steel ball.
Secondly, the steel ball must have sufficient impact time on the material, which is related to the ball filling rate and average ball diameter.When the load is constant, on the premise of sufficient impact force, the diameter of abrasive body should be reduced as much as possible, the number of steel balls should be increased, the impact times on materials should be increased, and the crushing efficiency should be improved.
Finally, the material stays in the mill long enough to ensure that it is completely pulverized, which requires the ball to have the ability to control the flow of the material.
The so-called two-stage ball matching method USES two different sizes and diameters of steel balls for grading.The theoretical basis is that the gaps between the big balls are filled by small balls to completely increase the density of steel balls.In this way, on the one hand, the impact capacity and impact times of the mill can be improved, which is consistent with the functional characteristics of the abrasive body.On the other hand, the higher packing density makes the material obtain certain grinding effect.In the two-stage ball, the function of the big ball is mainly to impact the broken material.The function of the ball is to fill the gap between the big balls, increase the volume density of the grinding body, control the material flow rate, and increase the grinding ability.The energy transfer function is used to transfer the impact energy of the big ball to the material.The third is to drain the coarse-grained material into the gap and place it in the impact zone of the larger ball.
When the material has small particle size and good wear resistance, multistage balls should be used, because the impact times of steel balls increase at this time.On the contrary, when the material has large particle size and high strength, it is the key to improve the impact force of steel ball.Therefore, using two-stage ball can show obvious advantages.
The influence of the two ball types is greatly affected by the material changes.Multistage ball is sensitive to material change and the output of ball mill fluctuates greatly.The two-stage ball is not sensitive to material changes and the yield is relatively stable.That is to say, when the material is more resistant, the output of the multistage ball increases more than that of the two-stage ball.On the contrary, the production of multi-stage ball decreased more than that of two-stage ball.Therefore, multistage ball is suitable for materials with small particle size and good abrasion resistance, while two-stage ball is suitable for materials with large particle size and poor abrasion resistance.