Mining fans are essential components in creating safe and productive underground mining environments. Two types of mining fans are main fans and auxiliary fans, which differ in their functions and applications. 

Main fans, also known as primary ventilation fans, are responsible for providing fresh air to the entire mine. These fans are usually large and powerful, designed to produce a high volume of air at a constant rate. Main fans are installed at the surface or underground, and they are used to move air through the main ventilation circuit of the mine. Main fans are commonly used in areas such as the mine entrance, haulage ways, and main airways. 

Auxiliary fans, also known as secondary ventilation fans, supplement the airflow provided by the main fans. Auxiliary fans are typically smaller and less powerful than main fans, but they offer more flexibility and can be moved to different locations as needed. Auxiliary fans are often used to provide ventilation to specific areas of the mine, such as working faces, crosscuts, and stopes. Auxiliary fans also help to remove harmful gases and fumes from the mining environment, improving the overall air quality. 

In summary, main fans and auxiliary fans serve different functions in mining operations. Main fans provide fresh air to the entire mine, while auxiliary fans supplement the airflow in specific areas. By understanding the unique functions and applications of each type of fan, miners and operators can create a safer and more productive working environment in their mines.