The main function of the steel ball in the ball mill is to impact and crush the material, and it also has a certain grinding effect. Therefore, the grading design of the steel ball is designed to meet these two needs. The quality of the crushing effect directly affects the grinding efficiency and ultimately determines the output of the ball mill. Whether the expected crushing effect can be achieved depends on whether the grading of the steel ball is reasonable, which mainly involves the size of the steel ball, the number of ball diameters, and the proportion of steel balls of different specifications.

When determining these parameters, in addition to considering the specifications, internal structure and product fineness requirements of the ball mill, it is also necessary to consider the characteristics of the material entering the mill, such as grindability and particle size.

In order to achieve effective crushing of materials, the following principles must be followed when determining the grading of steel balls:

First, the steel ball should have sufficient impact force to ensure that it can effectively crush the granular material, which is closely related to the maximum diameter of the steel ball.

Secondly, the number of times the steel ball impacts the material should be sufficient, which is related to the filling rate and average diameter of the steel ball. When the loading volume is fixed, it is necessary to minimize the diameter of the grinding body and increase the number of steel balls while ensuring sufficient impact force to increase the number of impacts on the material, thereby improving the crushing efficiency.

Finally, the material should have enough residence time in the mill to ensure that it is fully crushed, which requires the steel balls to have a certain ability to control the material flow rate.