We only introduce and analyze the wet rotary kiln process. Wet rotary kiln is usually long (length diameter ratio is 30 ~ 40). In order to increase the heat transfer area of the kiln, chains are often hung at the kiln tail to accelerate water evaporation. During the production of wet rotary kiln, water is added into the raw material mill to make the raw material into slurry with water content of 30% ~ 40%.