Why Are the Grinding Steel Balls of Ball Mill Worn Out?

When the ball mill machine is working, grinding steel balls are constantly squeezed and impacted by materials and other steel balls, which will cause the wear of grinding steel balls. The wear of grinding balls has a considerable effect on the quality of final product and the production efficiency of ball mill machine.

Therefore, it is very important to study the reasons of causing the grinding steel balls wear. On the basis of long-time theory and practice, Fote Machinery engineers have summarized the following factors.

1. The revolving speed and diameter of ball mill machine

The bigger diameter and the faster revolving speed of ball mill machine, the faster the grinding steel balls will move. When a ball mill machine is over three meters in diameter, it will increase the impact force to the grinding steel balls in the rotation and grinding process. Then the wear degree of grinding balls is more serious.

When the revolving speed of ball mill machine is fast, the cyclic rotation number of grinding steel balls increases, and the grinding steel balls will be worn out. However, the revolving speed of ball mill machine cannot be too slow, otherwise, it will affect the production efficiency of ball mill machine.

2. The properties of materials in the ball mill machine

The hardness, granularity, and shape of the materials in ball mill machine will have an extremely important influence on the grinding steel balls wear. The research shows that there will be two times the difference in the wear rate of grinding steel balls when the same ball mill machine processes materials with different hardness.

When the material hardness is lower than that of grinding steel balls, the fatigue wear of grinding steel balls holds a large proportion, which can cause the resources waste. As for the granularity of materials, the wear rate of grinding balls will increase with the increase of the material particle size.

3. Grinding mode of ball mill machine

The grinding method of ball mill machine can be roughly divided into wet grinding and dry grinding. When adding the same grinding balls and materials to the ball mill machine, adopting the wet grinding mode will cause more serious wear to grinding steel balls than drying grinding mode.

When the ball mill machine does the wet grinding, if the steel balls are in contact with the substance with a certain acidity or alkalinity, they will be corroded. Besides, the cutting force of material can damage the passive film of grinding steel balls. Then the corrosion and wear stimulate each other. As the result, the wear value of grinding steel balls in the wet grinding is higher than that of the dry grinding process.

4. Grinding steel ball itself

The diameter, material hardness and loading quantity of grinding steel balls can also affect the wear degree of grinding steel balls.

1) The greater the grinding steel balls diameter is, the heavier the steel ball is. When the revolving speed of ball mill machine is constant, the heavier grinding steel balls will have bigger kinetic energy while falling down. And the heavy grinding balls will suffer the bigger impact.

2) The abrasive resistance of grinding steel balls' raw material has a great relationship with its wear. For the hardness, the wear rate of grinding balls will decrease with the increase of its hardness. But they are not proportional to each other. When the hardness of grinding steel ball exceeds a certain value, the increase of its hardness will result in the increase of grinding balls brittleness, which will prompt the increase of its wear rate instead.

3) The larger loading quantity of the grinding steel balls is, the greater the collision probability among the grinding balls is. Then the grinding steel balls will more prone to have the fatigue wear phenomenon.

5. Ore pulp factor

Ore pulp includes the pH value of ore pulp and the concentration of ore pulp. Generally, the lower the pH value of ore pulp in the ball mill machine, the easier the grinding steel balls to wear. The lower the ore pulp concentration, the more serious the grinding balls wear.

6. Grinding aid

Although the grinding aid can reduce the mineral hardness and is beneficial to crush mineral for ball mill machine, it may increase the wear of grinding steel balls. Therefore, users shall carefully select and use the grinding aid.

In summary, there are many factors causing the grinding steel balls wear of ball mill machine. Thus, it is necessary for users to correctly understand the cause of grinding ball wear, which has great significance to improve the grinding efficiency of ball mill machine and reduce the ore dressing cost of users. Fote Machinery offers various superior grinding balls. If you don't see what you need, please consult us online and we will give you the best satisfaction.