The materials and grinding medium are mixed together, collide and squeeze each other. In case of dry grinding, because there is no material barrier in the crack, it is likely to squeeze the crack smaller and smaller in the process of extrusion, which will lead to low grinding efficiency and slow material separation speed. In case of wet grinding, when small cracks appear in large minerals, the fluidity of water will force the water flow into the cracks and block them. After the impact and extrusion of grinding medium, the cracks will gradually increase, and finally the large materials will be crushed. Therefore, the efficiency of wet grinding is high.
In addition to high grinding efficiency, wet grinding also has the characteristics of low noise, fine and uniform grinding particle size and less pollution to the working environment. The advantage of the dry grinding of the ball mill is that the grate plate mill tail is used for discharging, the discharging speed is fast and smooth, there is no belly swelling, the cylinder does not need cooling, and the service life is long.
The disadvantage of dry grinding is that there may be dead corners in the grinding. Once the materials enter the dead corners, they cannot come out without the drive of water, and they will not be grinded. The disadvantage of wet grinding is that dehydration and drying process must be carried out after grinding, which increases the cost.
1、 Different Working Principles of Wet Ball Mill and Dry Ball Mill
The main equipment of dry grinding of ball mill is dry ball mill. The structure of dry ball mill is much more complex than wet ball mill. It must be equipped with induced draft device, dust discharge pipe and dust collector, which is determined by its working principle. The dry grinding of the ball mill requires that the materials in the mill are dry and can not add water or other liquids. The materials are ground by the medium of the ball mill in the mill, and the products meeting the requirements are brought out by wind or air flow. If you want to know more about difference between rod mill and ball mill, please click here.
The main equipment of wet grinding of ball mill is wet ball mill. The structure of wet ball mill is simple without adding too many auxiliary accessories. Water or absolute ethanol needs to be added in the grinding process. In the grinding operation, large materials will produce cracks under the impact and grinding of ball milling medium, the cracks will gradually increase and deepen, and finally the materials will be separated from the cracks, so as to grind the large materials small.
2、 Different Scope of Application
Dry ball mill is suitable for materials that will react with water, such as cement, lime, marble and other building stones. Other substances may be produced in case of water, so it is not suitable for wet grinding. Some products are required to be stored and sold in the form of powder, which is also suitable for dry grinding. In addition, due to the lack of water resources in some arid areas, dry grinding can also be used in order to save water.
Wet ball mill, wet grinding is applicable to most materials, all kinds of metal ores and non-metal ores. As long as there is no reaction in case of water, which affects the quality of finished products, wet grinding can be used. Common materials include copper ore, iron ore, molybdenum ore, phosphate ore, feldspar ore, fluorite ore, etc. During wet grinding, the proportion of steel ball, material and water is 4:2:1. The specific proportion needs to be determined through grinding test.
The above is the difference between dry ball mill and wet ball mill summarized by Fodamon engineer, and how to choose them. Only by identifying the grinding mode suitable for the materials can the ball mill operate with high quality and efficiency. The two grinding equipment have their own advantages. We still make a rational choice after considering the material properties, characteristics, product requirements and working environment.