After a long time operation, the ball mill will encounter the problem of reduced grinding efficiency, which not only affects the normal operation of the entire concentrator, but also damages the economic benefits of the mine owner. So, in production practice, how can we effectively improve the grinding efficiency of the ball mill? You can start from the following 7 aspects.

1. Enhance the grindability of raw ore

Generally, the hardness, degree of dissociation, size and structure of the raw ore determine the grindability of the raw ore. The grindability is small, indicating that the raw ore is easy to grind, and the wear on the ball mill liner and grinding media is relatively small, and the energy consumption is low; the large grindability indicates that the raw ore is difficult to grind, and the wear on the ball mill lining and the grinding media is also large. High energy consumption. This shows that the grindability of the raw ore will directly affect the grinding efficiency of the ball mill.

Therefore, in production, when the raw ore is difficult to grind and the particle size is required to be finer, we can take certain measures to enhance the grindability of the raw ore, such as take certain measures to enhance the grindability of the raw ore, such as adding chemicals in the grinding process to increase the grinding efficiency; or work hard on the grindability of the raw ore: heating the minerals in the raw ore, reducing the hardness, etc.

2. More crushing and less grinding, reducing the particle size of the ball mill

The larger the grinding particle size, the greater the work done by the ball mill on the ore, and the grinding efficiency of the ball mill will naturally be affected. In order to achieve a qualified grinding fineness, the workload of the ball mill will inevitably increase, and the energy consumption will also increase.

To reduce the feed size, the crushed product must have a small particle size, that is, 'more crushing and less grinding'. In this way, if the feed size is appropriate, the grinding efficiency of the ball mill will increase accordingly.

3. Maintain a proper filling rate of steel balls

When the speed of the ball mill is kept constant, the greater the filling rate of the steel ball, the more times the material will be hit, and the grinding area will increase. Correspondingly, the grinding efficiency of the earth mill will also increase, but at the same time, the energy consumption will also increase. 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 particles of materials. In production practice, most mines will set the filling rate to 45%~50%, but this is only a rough range, because the actual conditions of each beneficiation plant are different, blind copying will not achieve the ideal grinding efficiency, it depends on the situation.

4. Reasonably add steel balls

In the long-time operation and grinding process of the ball mill, the steel balls will be worn out, resulting in changes in the ratio of steel balls of different sizes, resulting in changes in the fineness of the grinding products, and thus affecting the grinding efficiency of the ball mill. Therefore, the operator of the ball mill needs to check the condition of the steel ball regularly, and reasonably add the steel ball to ensure the stable production of the ball mill.

5. Strictly control the grinding concentration of the ball mill

Generally, the 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 grinding concentration is low, the slurry flows quickly, and the material is not easy to stick around the steel ball, which weakens the impact and grinding effect on the material, resulting in unqualified discharge particle size, and the grinding efficiency of the ball mill is not high; the grinding concentration is high and the material is easier to move around the steel ball, the impact and grinding effect on the material is enhanced, but the slurry flows slowly, which is easy to cause over-grinding.

In production practice, the grinding concentration is controlled by controlling the amount of ore supplied by the ball mill, the amount of water supplied by 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.

6. Optimize the grinding process of the ball mill

According to the ore properties of the raw ore (useful mineral dissemination particle size, monomer dissociation degree, gangue mineral dissemination particle size) to optimize the grinding process, such as pre-throwing, pre-enrichment, stage grinding, pre-grading. On the one hand, reducing the amount of grinding, on the other hand, recovering useful minerals in time, which can improve the grinding efficiency of the ball mill.

7. Improve classification efficiency

The effect of classification efficiency on grinding efficiency is self-evident. High classification efficiency means that qualified particles can be discharged in a timely and efficient manner, while low classification efficiency means that most qualified particles cannot be discharged and returned to the ball mill for regrind, which is likely to cause over-grinding. In production, two-stage classification or improvement can be used to improve the classification efficiency, and correspondingly improve the grinding efficiency of the ball mill.

In the grinding process, there are many factors that affect the grinding efficiency of the ball mill. Many factors can only be analyzed and judged qualitatively, and it is difficult to make a quantitative analysis. This requires the ball mill technicians to analyze according to the actual production situation on site and the qualitative analysis results, and finally get reasonable technical parameters to guide the on-site production and strive for the ideal ball mill grinding efficiency.