In the powder grinding process of Ultrafine Mill , the grinding efficiency has a great relationship with the grading of grinding balls. To improve its working efficiency, here experts from Henan Zenith Mining Machinery Co., Ltd. will give a brief introduction to the four grading principles of grinding balls in tube mill.
1. Determination of average sphere diameter and the maximum diameter of grinding balls in the first cabin.
The maximum diameter of grinding balls in the first cabin is usually determined by the formula of 28∛D. The practice has proved that many cement plants use this formula as the basis of determining the maximum diameter of Φ2.2m powder grinding mill, but it is not suitable for large-sized grinding plant. The large the grinding mills are, the smaller of the maximum diameter of the grinding balls in the first cabin will be. From the crushing and grinding effect, the average diameter and the maximum diameter of the grinding balls in the first cabin should be properly reduced to improve the crushing and grinding effect.
2. Determination of average sphere diameter and the maximum diameter of grinding balls in the second cabin.
The maximum diameter of the grinding balls in the second cabin should be the minimum diameter of the grinding balls in the first cabin, and the average diameter should decrease progressively. The grading should be Level 3 or Level 2.
3. Determination of average diameter of grinding balls in the third cabin.
The average diameter of grinding balls in the first cabin is small, and it should allow for the flowing speed of materials. The determination should follow the principle of not blocking the grate bar. Of course, grinding rod can also be used, but the circle coefficient of final particles and flow velocity of the particles will decrease.
4. Determination of loading capacity of grinding balls.
With the goal of high output of qualified final products, gradually increase the loading capacity of every cabin to reach the optimum state. As for open-circuit powder grinding system, successively increase the loading capacity in the first, second and third cabin and gradually adjust to the best state.