The rotary dryer also called drum dryer, which is a type of industrial dryer employed to reduce or minimize the liquid moisture content of the material. It is handling by bringing it into direct contact with a heated gas. The dryer is made up of a large and rotating cylindrical tube, usually supported by concrete columns or steel beams.

The dryer slopes slightly so that the discharge end is lower than the material feed end in order to convey the material through the dryer under gravity. Material to be dried enters the dryer, and as the dryer rotates, the material is lifted up by a series of internal fins lining the inner wall of the dryer. When the material gets high enough to roll back off the fins, it falls back down to the bottom of the dryer, passing through the hot gas stream as it falls. This gas stream can either be moving toward the discharge end from the feed end, or toward the feed end from the discharge end. The gas stream can be made up of a mixture of air and combustion gases from a burner, in which case the dryer is called a direct heated dryer.

Rotary dryer is suitable to dry metallic and nonmetallic mineral, clay in coal slime in coal mine,etc. Rotary dryer can be widely used to dry various materials, and it is simple to be operated.