Abstract: The No. 2 Mine′s Coal Preparation Plant of Yangquan Coal (Group) Co. Ltd is facing the trouble that the existing slime drying system is abnormal in operation and low in capacity and its exhaust emissions are not up to the specified standard. To solve the problem, work is made on the renovation of the system based on analysis of the causes of the troubles, and finally the rotary-vane dryer is used in place of the drum version. Practice shows that the dried product can well meet the technical requirements for use as power coal blend and the exhaust gas emission is up to the specified standard.