Ball Mill Grinding
Ball mill grinding is to continue grinding the crushed material, and then discharge it from the ore outlet after grinding to the required particle size. The feed size of the ball mill is usually ≤25mm, and the output size is between 0.074mm ~ 0.4mm. The output particle size and qualified rate are related to the grinding process and grinding process of the ball mill. The following briefly introduces the ball mill grinding process and grinding process optimization.
Ball Mill Grinding Process
The grinding method of the ball mill can be divided into two types: dry and wet.
1. Open circuit grinding
The open-circuit grinding is only carried out once, and the sorting is not carried out through the classifier. All the discharged products are directly sent to the next process. The characteristics of open circuit grinding are simple process, less auxiliary equipment, small floor area and low investment. In order to improve the product qualification rate and improve the grinding efficiency, you can optimize the structure of the mill, add an activation device in the fine grinding bin, and add a special discharge grate plate at the ore discharge port. To avoid the discharge of products that meet the standards, special separation device to increase production and reduce energy consumption.
2. Closed circuit grinding
Closed-circuit milling is a closed-circuit milling system composed of a ball mill and a classifier. After the materials are ground by the ball mill, they enter the classifier for sorting. The qualified products are discharged into the next process. The coarser products are returned to the ball mill to continue grinding until the particle size reaches the standard. The disadvantages of this grinding process are that there are many auxiliary equipment, a large floor area and high investment. However, the advantages are also obvious. Large output, high efficiency, high product qualification rate, less over-grinding, easy adjustment of product fineness, output increase of 20%, and energy consumption are reduced by about 10% compared to open-path grinding.
Ball mill grinding process optimization
1. Optimize the structure and environment of the mill. The internal structure of the mill is of great help to improve the grinding environment. We can optimize the internal structure of the mill from the aspects of reasonable configuration of the silo plate and the installation of the grate plate at the discharge end. In addition, in the environment of the mill, it is necessary to pay attention to the ventilation inside the mill, the temperature inside the mill to be controlled below 80℃, and the humidity of the material to be controlled within a reasonable range.
2. Optimize the ratio of grinding media and add regularly. Reasonable ball mill media ratio is very important, usually need to add large, medium and small balls of different diameters and sizes, and follow the principle of small balls and more balls, the specific ratio should be determined by grinding tests. In addition, it is necessary to calculate the time and number of adding steel balls according to the ball loading amount of the mill and the wear of the steel balls. Regular addition of steel balls can ensure the smooth grinding process and improve the grinding efficiency.
3. With the aid of grinding aids and other auxiliary products. For some materials with high hardness, we can add a small amount of grinding aid to enhance the grinding effect and improve the grinding efficiency. The role of grinding aids is to stimulate the activity of the mineral surface, making it easier to grind. However, some materials will have a chemical reaction with grinding aids. Avoid using grinding aids for such materials.
