How to Improve The Grinding Efficiency of The Ball Mill?

Effectively improving the grinding efficiency of the ball mill can increase the output and improve the efficiency of the concentrator. After the long-term operation, most concentrators will encounter the problem of reduced grinding efficiency of ball mills, which affects the normal operation of the entire concentrator. Following are some methods for improving the grinding efficiency of the ball mill.

1. Reducing the grindability of raw ore

The hardness, degree of dissociation, size and structure of the raw ore determine the grindability of the raw ore. The small degree of grinding indicates that the raw ore is easy to grind, and the wear on the liner of the ball mill and the grinding media is relatively small. A large degree of grindability indicates that the raw ore is difficult to grind, and the wear of the ball mill liner and grinding media is also large, and the energy consumption is high. Therefore, the grindability of the raw ore will directly affect the grinding efficiency of the ball mill.

In production, when the raw ore is difficult to grind and the particle size is required to be fine, some measures can be taken to enhance the grindability of the raw ore. Such as, adding chemicals in the grinding process to increase the grinding efficiency, or heating the minerals in the original ore to reduce the hardness.

2. Improving classification efficiency

If the classification efficiency is low, most of the qualified granular products cannot be discharged and returned to the ball mill for re-grinding, which will cause over-grinding. In production, two-stage classification or improved classification equipment can be used to improve classification efficiency, and correspondingly improve the efficiency of ball mill grinding.

3. Controlling the grinding concentration of the ball mill

Grinding concentration will affect the specific gravity of the slurry, the fluidity of the slurry, and the degree of adhesion of the ore particles to the steel ball. The low-concentration slurry flows fast, and the material is not easy to adhere to the steel ball, which weakens the impact and grinding effect on the material, resulting in unqualified discharge particle size and low grinding efficiency of the ball mill. With high concentration, the material is easier to adhere to the steel ball, which enhances the impact and grinding effect on the material, but the slurry flows slowly, which is easy to cause over-grinding.

In production practice, the grinding concentration can be controlled by controlling the amount of ore supplied by the ball mill, the water replenishment amount of the ball mill, or by adjusting and controlling the particle size composition and moisture in the graded returned sand to help improve the grinding efficiency of the ball mill.

4. Reducing the grinding particle size

The larger the grinding particle size, the greater the workload of the ball mill in order to achieve the qualified grinding fineness, the grinding efficiency of the ball mill will naturally be affected, and the energy consumption will increase accordingly. When the finished product is crushed with small particle size, the feeding particle size of the ore grinding will be small, and the grinding efficiency of the ball mill will be improved accordingly.

5. Maintainproper ball filling rate

When the speed of the ball mill is kept constant, the greater the filling rate of the steel ball, the more the number of blows to the material, the larger the grinding area, and the higher the grinding efficiency of the ball mill. However, if the filling rate of the steel ball is too high, the motion state of the steel ball will easily change, which will reduce the impact on large-particle materials.

In production practice, the filling rate of steel balls for lattice ball mills is generally 45% to 50%, while the filling rate of steel balls for overflow-type ball mills is generally 38% to 42%. The operator needs to check the condition of the steel balls regularly, and reasonably add the steel balls when they are worn to ensure the stable production of the ball mill.

6. Optimize the grinding process

Optimize the grinding process according to the ore properties of the original ore, such as pre-throwing, pre-concentration, stage grinding, and pre-classification, which can reduce the amount of grinding, recover useful minerals in time, and improve the grinding efficiency of the ball mill.