Circumgyrate kiln is a generalized term, and can be classified into different types according to different roasting materials and different using methods. There are some common used rotary kilns, such as, cement rotary kiln, clay rotary kiln, clinker rotary kiln, cylinder rotary kiln, indirect fired rotary kiln, dry and wet types rotary kiln, dry process rotary kiln, lime rotary kiln, ore rotary kiln, etc.