Why the output of ball mills is getting lower?
When we buy a ball mill, the manufacturer’s manual will have detailed technical parameters, and generally give a range of output values. But after running for a period of time, the output may become lower, so what is the reason for the lower and lower output of the ball mill?
1. overage grinding
When the output of the ball mill is getting lower and lower, we should first consider whether there is "overage grinding", which is the main factor that affects the output of the ball mill.
The reasons for "overage grinding" are too much feed; the hardness of the grinding material becomes harder and the particle size becomes larger; the water content of the grinding material is too large; the steel ball grading is unreasonable; the partition board or the grate seam is mixed Blockage.
The solution to the "overage grinding" problem: reduce the amount of feed; when the size or hardness of the grinding material changes, make corresponding adjustments in time; adjust the water content of the grinding material; reasonably configure the ratio of large, medium and small steel balls; clean up Blockage of compartment board or grate seam; increase the ventilation of the ball mill cylinder.
2.Long working hours
The length of the ball mill working time directly affects the product composition and purity, and the ball milling time also has a significant effect on the particle size. In the initial stage, with the extension of time, the particle size decreases rapidly, but after the ball milling for a certain period of time, even if the ball milling time continues to be extended, the particle size value of the product does not decrease too much. Different samples have different best grinding times. On the other hand, the longer the milling time, the more serious the pollution will be, which will affect the purity of the product.
3. Failure to add steel balls in time
The grinding effect of the ball mill and the level of output are restricted by the steel balls of the ball mill. However, with the grinding and impact in the cylinder, the steel balls will wear out, so it is necessary to add steel balls in time to ensure the consistency of ball mill output to a large extent.
4. The temperature in the cylinder rises
The temperature of the ball mill increases during operation, the effective strain of the ball mill to form nanomaterials decreases, and the crystal grain size increases, which significantly affects the mechanical properties of the powder into a block. And no matter whether the final product of ball milling is a solid solution, intermetallic compound, nanocrystal, or amorphous phase, diffusion is involved, and diffusion is affected by the grinding temperature, so the temperature is also an important factor affecting the output of the ball mill.
5. The material moisture content is too high
Due to the large moisture content of the material, the uniformity of the feeding is affected and the feeding time is prolonged. Secondly, because the wet material is fed too much, it may cause the phenomenon of paste ball and paste liner in the mill, and even "full grinding" will be forced to stop the grinding process. Generally speaking, for every 1% increase in the comprehensive moisture of the material entering the mill, the output of the ball mill will decrease by 8%-10%; when the moisture is greater than 5%, the ball mill basically cannot perform grinding operations.
6. The addition ratio of grinding aids is unreasonable
The national standard stipulates that grinding aids are allowed to be added in the cement production process, but the mixing amount shall not exceed 1%. Additions exceeding this standard are unreasonable. In addition, most grinding aids are substances with strong surface activity and are not suitable All materials should be added reasonably according to the nature of the materials.
If the output of your ball mill is getting lower and lower, you can conduct investigations based on the above reasons to find the crux of the problem, solve the problem of low output from the root cause, and resume production as soon as possible.