Industry Reports
The reason why the output of the ball mill fails to meet the design requirements
In the production of ball mills, it is a common problem that the output does not meet the design requirements. In order to facilitate efficient production, this article summarizes 10 reasons why the output of the ball mill fails to meet the requirements.
1. The length ratio of each warehouse is unreasonable
An unreasonable ratio will cause an imbalance in the ability of coarse grinding and fine grinding, and the product will be too coarse or too fine, which will affect the output.
2. The particle size of the grinding material is larger
If the particle size of the material is large, it is difficult to adapt to the impact and grinding effects of the grinding body, and the ball mill. The bin is forced to load more steel balls to enhance the ability to impact the grinding material. The first warehouse is responsible for the crushing function, which makes the crushing process unreasonable. The crusher has a high functional utilization rate, increasing the crushing of the grinding head and reducing the particle size of the grinding, which can not only reduce the energy consumption, but also increase the output.
3. The ventilation in the mill is not good
Strengthening ventilation can discharge the fine powder in the mill in time, reduce the phenomenon of over-grinding, and thus can improve the grinding efficiency.
Strengthening ventilation can remove the water vapor in the mill in time, reduce the adhesion of fine powder, prevent the paste ball and grate holes from being blocked, and ensure the normal operation of the ball mill.
4. The moisture content of the grinding material is too large
When the water content of the material is large, the grinding body and the lining plate will be adhered to form a "buffer pad", and at the same time, the grate plate will be blocked, causing "saturated grinding". However, the water entering the mill is not as low as possible, but should be kept within a certain range.
5. The gradation of the grinding body is unreasonable
In order to meet the requirements of the impact and grinding of materials with different particle sizes, increase the impact and grinding opportunities of the grinding body on the material, and improve the grinding efficiency, the grinding body must be reasonably graded. Its range is generally between 25% and 35%, with 28% to 32% in the majority.
When the grindability of the material is poor, or when the fineness of the grinding is required to be fine, the filling rate of the first bin should be lower, preferably not higher than 28%. When producing low-grade cement, the filling rate of one silo should be higher, and vice versa. When producing pozzolanic cement, the filling rate of one silo should be higher, and when producing slag cement, the filling rate of one silo should be lower. The filling rate of the segment warehouse should not be too high.
6. The influence of the temperature of the grinding material
If the temperature is too high, the grinding efficiency will decrease. In order to reduce the cement temperature in the mill, a small amount of mist water can be sprayed into the grinding chamber, and the small mill can adopt the method of spraying water on the grinding body.
7. The influence of the grindability of materials
The grindability of the material refers to the difficulty of grinding the material, and the national standard stipulates that it is expressed by the grinding work index Wi (kwh/t). The smaller the value, the better the grinding of the material, and the harder it is on the contrary. Cement plants are accustomed to use the relative grindability coefficient to express the difficulty of the material being ground.
8. The influence of grinding aids
We can add grinding aids to the ball mill without harming the performance of the product. Most of the commonly used grinding aids are organic substances with strong surface activity. In the process of material grinding, they can be adsorbed on the surface of the material, accelerate the crack propagation in the material crushing, reduce the mutual bonding between fine powders, and improve the grinding efficiency. It is beneficial to the energy saving and high yield of the ball mill. The national standard stipulates: Grinding aids are allowed to be added in the cement production process, but the mixing amount shall not exceed 1%.
9. Influence of grinding process
For a ball mill of the same specification, the output of the closed-circuit process is 15-20% higher than that of the open-circuit process; during closed-circuit operation, choosing the appropriate powder selection efficiency and cycle load rate is an important factor to improve the mill output.
10. The fineness requirements of the milled materials
The finer the fineness of the milled material, the lower the output, and vice versa, the higher the output.
