Explain the difference between wet ball mills and dry ball mills

Materials and grinding media are mixed together, colliding and squeezing each other. If it is dry grinding, due to the lack of material obstruction in the cracks, it is very likely that the cracks will become smaller and smaller during the squeezing process, which will cause low grinding efficiency and slow material separation speed; If it is wet grinding, when small cracks appear in large minerals, the fluidity of water will force water flow into the cracks, creating a barrier effect. After being impacted and squeezed by the grinding medium, the cracks will gradually increase, ultimately causing the large materials to be crushed, so the efficiency of wet grinding is high.

Wet ball mills not only have high grinding efficiency but also have the characteristics of low noise, fine and uniform grinding particle size, and less pollution to the working environment.

The advantage of a dry ball mill lies in the use of a grate plate mill for tail discharge, which has a fast and smooth discharge speed and no bulging phenomenon. The cylinder does not require cooling and has a long service life.

The disadvantage of a dry ball mill is that there may be dead corners inside the mill. Once the material enters the dead corner, it cannot be ground out without the drive of water; The disadvantage of wet grinding is that it also involves dehydration and drying processes after grinding, which increases costs.

1、 Different working principles

The structure of a dry ball mill is much more complex than that of a wet ball mill, and it must be equipped with an air induction device, a dust exhaust pipe, and a dust collector, which is determined by its working principle. The dry grinding of the ball mill requires that the materials inside the mill are dry and cannot be mixed with water or other liquids. The materials are ground by the ball mill medium inside the mill, and the products that meet the requirements are carried out by wind or airflow.

The structure of a wet ball mill is simple, without the need for excessive auxiliary accessories. During the grinding process, water needs to be added. During the grinding operation, large blocks of material will crack under the impact and grinding of the ball milling medium, and the cracks will gradually increase and deepen. Finally, the material will separate from the crack, thereby achieving the effect of grinding small blocks of material.

2、 Applicable scope varies

Dry ball mills are suitable for materials that react with water, such as cement, lime, marble, and other building stones. They may produce other substances when exposed to water, so they are not suitable for wet grinding. Some products require storage and sales in the form of powder, and are also suitable for dry grinding; In addition, in some arid areas where water resources are relatively scarce, dry grinding can also be used to save water.

Wet ball mills are suitable for most materials, including various metallic and non-metallic ores. Materials that do not react with water and thus affect the quality of finished products can be wet ground. Common types include copper ore, iron ore, molybdenum ore, phosphate ore, feldspar ore, fluorite ore, and so on. The ratio of steel balls, materials, and water during wet grinding is usually 4:2:1, and the specific ratio needs to be determined through grinding experiments.

The above is the difference between dry ball mills and wet ball mills, and how to choose between the two. Only by finding the appropriate grinding method for the materials can the ball mill operate efficiently and with high quality. Both types of grinding equipment have their own advantages. Therefore, we should make a rational choice after considering the properties, characteristics, product requirements, working environment, and other aspects of the materials.