Depending on the drying and humidity of the material, the ball mill can be divided into a dry ball mill and a wet ball mill. In foreign countries, dry ball mills account for a large proportion in about 50 years, accounting for about 70%. With the advancement of technology and the continuous improvement of energy conservation and environmental protection requirements, the development of wet ball mills is very rapid, and ultra-dry ball mills account for more than 75% of the total number of ball mills. Compared to dry ball mills, wet ball mills have several advantages:
One: The investment in wet ball mills is generally lower than that of dry ball mills. Under the same conditions, the investment in wet ball mills is roughly the same as the investment in ordinary grinding processes. The dry ball mill has a large number of auxiliary equipment for the wind system, while the wet ball mill has fewer auxiliary equipment and the material transport device is simple, so the investment is about 5%~10% lower than the dry ball. Wet ball mills themselves require more power than dry ball mills, but dry ball mills and air systems consume more power than wet ball mills.
Two: For continuous dry ball mills, due to the influence of ore humidity, a very thin material is formed on the ore and lining surfaces, so the energy consumption per ton of ore is 25% to 30% higher than that of a wet ball mill.
Three: The dry ball mill has stricter requirements on the water content of the ore. When there is a large amount of clay, the water content should be less than 49%. When the clay content is small, the water content is about 5%, which has little effect on production. When the water is large, it will cause the ore to be reduced or even discharged. In order to reduce the amount of water, the hot air facility is increased, thereby increasing the investment and production cost of the dry ball mill. The wet ball mill can handle watery and high muddy ore. When low grade magnetic iron ore is selected, the wet ball mill is easy to obtain any desired particle size and is suitable for magnetic separation.