The ball mill uses the rotation of its own cylinder body to bring the material in the cylinder body and the grinding body to a certain height and then fall, causing them to squeeze, impact and grind and peel each other, thereby achieving the purpose of grinding the material.In actual production, sometimes the grinding effect is not good, and the grinding particles are too large. Do you know the reason?How should we adjust in this situation?

Factors affecting the particle size of grinding ore

1. The number of grinding media

As the grinding medium of a ball mill, steel balls play an important role in grinding operations. Only steel balls with sufficient quantity and reasonable size ratio can fully impact and peel the material, so that the material can be crushed.If the number of grinding media is too small, or the ratio is unreasonable, many materials will not be ground, and the particle size of the product will be too large.

2. The feed volume is too large

Only by retaining enough space in the cylinder can there be a dive force when the material rotates to the highest point to complete the grinding.If the feed volume is too large and the cylinder body is stuffed full of steel balls and materials, the materials cannot be fully ground, which can easily cause the problem of product particles being too large.

3. Slurry concentration

When the ball mill is running, if the concentration of the slurry is too high and the moisture is too small, the slurry will stick to the grinding body or liner, forming a “buffer cushion”, which affects the grinding capacity of the ball mill, making it difficult for the material to be fully ground, resulting in the final discharge particle is too large.

4. Ore hardness

The different hardness of the raw ore will also affect the grinding effect. For some higher hardness ores, the particle size of the product will be larger within the same grinding time. In this case, the grinding time can be increased or a grinding aid can be added to ensure the grinding particle size.

5. The size of the grinding material

Ore is generally broken by a crusher and then enters a ball mill for grinding. If the crushing effect is poor in the crushing stage, then the incoming material into the ball mill will be larger, so at the same grinding time, the particle size of the mineral discharge with a large particle size must also be large, so it is necessary to ensure the particle size of the incoming material.

6. The impact of the classifier

The ball mill cooperates with the classifier to complete the grinding and grading operations. Many related parameters of the classifier will affect the particle size of the product, such as the speed, the lifting height of the spindle, the wear of the blade, and the level of the overflow weir. , etc., will affect the particle size of the product.

7. The situation of steel balls

The condition of the steel ball will also affect the particle size of the product, including the diameter of the steel ball, the filling amount, the material and the movement method.

How to adjust the particle size of the ball mill?

1. Adjustment of grinding medium

If it is found that the discharge particle is too large due to the grinding medium, it should be adjusted in time.First of all, the filling rate should be maintained at about 40% of the volume of the cylinder.In addition, the ratio of large balls can be appropriately increased, especially when dealing with materials with higher hardness or larger pieces, large balls can provide a stronger impact force and crushing capacity, which helps to crush the material more effectively in the rough grinding stage.

2. Control the amount of feed

When setting the feeding amount, a reasonable upper limit of feeding should be set according to the grinding capacity of the ball mill. In addition, suitable equipment can be used to monitor the feeding amount, such as quantitative feeding scales. The operator can accurately control the feeding situation based on the data fed back by this equipment.

3. Adjust the moisture of the slurry

When adjusting the moisture of the slurry, the moisture of the slurry should be gradually increased to an appropriate level.To determine whether the moisture is appropriate, you can refer to the following criteria. If the moisture is increased, the slurry can maintain good fluidity, and it will not be too viscous and stick to the grinding body or liner to form a “buffer cushion”, and the material can be fully ground and refined during the grinding process. There is no situation where the grinding is blocked and the particle size becomes larger due to moisture problems, which means that the moisture of the slurry at this time is in the appropriate range.

Through the above three methods, the grinding particle size of the ball mill can be basically controlled to avoid the problem of excessive particle size. In addition, it is necessary to pay timely attention to the situation in the mill, and if there is full grinding and other phenomena, it is necessary to intervene in time to obtain qualified grinding products.