Ball mills can be classified into dry ball mills and wet ball mills based on the moisture content of the materials they process. Abroad, five decades ago, dry ball mills accounted for a significant proportion, approximately 70%. With technological advancements and increasing demands for energy conservation and environmental protection, wet ball mills have experienced rapid development and have now surpassed dry ball mills, accounting for over 75% of the total ball mills. Compared to dry ball mills, wet ball mills offer the following advantages:

1. The investment in wet ball mills is generally lower than that in dry ball mills. Under the same conditions, the investment in a wet ball mill is roughly equivalent to that in a typical grinding process. Dry ball mills require an additional air duct system and more auxiliary equipment, whereas wet ball mills have fewer auxiliary equipment and simpler material handling devices, resulting in an investment approximately 5%-10% lower than that of dry ball mills. Although wet ball mills require higher power for their operation, the total power consumption of dry ball mills, including the air duct system, exceeds that of wet ball mills.

2. For continuously operating dry ball mills, due to the influence of ore moisture, a thin layer of material forms on the surface of the ore and lining plates. Consequently, the energy consumption per ton of ore is 25%-30% higher than that of wet ball mills.

3. Dry ball mills have relatively strict requirements for the moisture content of raw ore. When the ore contains a high amount of clay, the moisture content should be below 49%; when the clay content is low, a moisture content of around 5% has little impact on production. However, excessive moisture can lead to reduced or even blocked ore discharge. To reduce moisture, additional hot air facilities are necessary, which increases both the investment and production costs of dry ball mills. In contrast, wet ball mills can handle ores with high moisture and clay content. When beneficiating low-grade magnetic iron ores, wet ball mills can easily achieve the desired particle size and are suitable for magnetic separation.