News Date:2021-12-15 15:40:50
In the production of ball mills, it is a common problem that the output fails to meet the design requirements. In order to facilitate efficient production, this article summarizes 10 reasons why the output of the mill does not meet the requirements for reference.
1. The length ratio of each warehouse is unreasonable
An unreasonable ratio will result in an imbalance between the rough grinding and fine grinding abilities, and the product may be too fine or too fine, which will affect the output.
2. The granularity of the material to be milled is large
If the particle size of the material is large, it is difficult to adapt to the impact and grinding action of the grinding body, and the ball mill. The warehouse is forced to load more steel balls to enhance the ability of impacting and grinding the material. A warehouse is responsible for the crushing effect, which makes the crushing process unreasonable. And the function utilization rate of the crusher is high, 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. Poor ventilation in the mill
Enhanced ventilation can discharge the fine powder in the mill in time, reduce the phenomenon of over-grinding, and improve the grinding efficiency.
Enhancing ventilation can remove water vapor in the mill in time, reduce the adhesion of fine powder, prevent the paste balls and grate holes from clogging, and ensure the normal operation of the ball mill.
4. Too much moisture in the grinding material
When the water content of the material is large, the grinding body and the liner will be adhered to form a "cushion pad", and at the same time it will block the grate board and cause "saturation". However, the lower the water entering the mill, the better, 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 action of materials of different 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. The range is generally between 25% and 35%, with 28% and 32% being the majority.
When the material is easy to grind, or when the fineness of the grinding is required, the filling rate of a warehouse should be lower, and it is better not to be higher than 28%. When producing low-grade cement, the filling rate of one warehouse should be higher, and vice versa. When producing pozzolanic cement, the filling rate of one bin should be higher, and when producing slag cement, the filling rate of one bin should be lower. The filling rate of the segment warehouse should not be too high.
6. The influence of the temperature of the material entering the mill
The temperature is too high, causing the grinding efficiency to drop. In order to reduce the temperature of the cement in the mill, a small amount of mist water can be sprayed into the grinding bin, and the small mill can adopt the method of water spraying on the mill body.
7. The influence of material grindability
The grindability of the material refers to the difficulty of the material to be ground, and the national standard stipulates that it is expressed by the pulverization work index Wi (kwh/t). The smaller the value, the better the material to grind, and vice versa the harder it is to grind. Cement factories are accustomed to using relative grindability coefficients to indicate how easy it is to grind materials.
8. The influence of grinding aids
We can add grinding aids to the ball mill without harming the performance of the product. Commonly used grinding aids are mostly organic substances with strong surface activity. During the grinding process, they can be adsorbed on the surface of the material, accelerate the crack propagation in the material crushing, reduce the mutual adhesion between fine powders, and improve the grinding efficiency. It is conducive to the energy-saving and high-yield of the ball mill. 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%.
9. The influence of the grinding process
For the ball mill of the same specification, the output of the closed-circuit process is 15-20% higher than that of the open-circuit process; in closed-circuit operation, selecting the appropriate powder selection efficiency and cycle load rate is an important factor in increasing the output of the mill.
10. The fineness requirements of the grinding material
The finer the fineness of the grinding material is required, the lower the output, and vice versa, the higher the output.
