In the cement industry, using dry process to product, all sorts of hydrous materials, such as raw materials, coal and mixing materials are needed to be dried. When using wet process, coal and composite material also need to be dried, so that we can guarantee the normal grinding operations. All of these need the rotary dryer to complete.

The moisture in the materials has a great effect on the output of grinding machine, the production quality and the operation of grinding mill. If the materials have more moisture, the humidity of the grinding machinery is above the average, fine materials will adhere to grinding body, lining board and shifting board, resulting in grinding efficiency decrease. Moreover, the more moisture in material will inevitably make grinding mill working conditions worsened, and then bring about more difficult to its operation and quality control.
 
In addition, the materials fed into the grinding mill, its mix proportion will change by the wave of the moisture changes in the material, and thus the grinding production quality also will be affected. Therefore, using rotary dryer to eliminate the exceed moisture is an essential segment in cement production.