There are various samples that need to be ground in the laboratory, and the grinding requirements and characteristics of each sample are also different for each experiment. Therefore, when using a ball mill to crush materials, the ball mill tank and grinding medium cannot remain unchanged. Among them, grinding balls, as a common grinding medium, have certain selection standards.

Selection criteria for grinding balls in ball mills

1. Material selection

Material selection needs to consider the density, hardness, and chemical properties of the material to be ground. Generally speaking, we need to choose grinding balls with higher density and hardness than the sample in order to achieve the desired grinding effect; In addition, during the operation of the ball mill, a large amount of heat is generated in the ball milling tank due to friction and impact, which requires good thermal stability of the grinding ball and the inability to undergo physical and chemical reactions with the material to be ground, in order to avoid contaminating the sample.

2. Selection of Volume Size

Grinding balls of different volume sizes have different effects, so we need to configure them separately (the commonly used sizes are 3mm, 5mm, and 10mm). The large ball has a heavy weight and a strong impact force on the material, which can easily crush the material, but it is difficult to finely grind and prone to grinding dead corners; Small balls have a small volume and a high number of impacts, which have a significant effect on the grinding of small materials. However, their impact force is small, making it difficult to grind large materials. Generally speaking, we can choose three different volume sizes of grinding balls.

3. Quantity configuration

Due to the different functions of the large and small balls, we need to allocate their quantity reasonably. For the quantity, we can use the principle of "equal surface area" to configure. First, calculate the surface area of different grinding balls based on their diameters, and then make the total surface area of different grinding balls roughly equal.

4. Ball material assembly ratio

In the process of ball milling, we need to reserve a certain space in the ball milling tank to play an effective role, so we cannot fill it too full. In addition, to achieve good ball milling results, it is recommended to maintain a mass ratio of 0.9 to 1.1 between the grinding ball and the sample material.

The selection criteria for grinding balls in ball mills have been shared with you here for your reference. In fact, the specific situation of each experiment is different. We can make scientific and reasonable changes according to the specific requirements of the experiment in order to achieve good grinding effect.