Abstract: In order to solve problem of low dewatering efficiency and poor effect of the original filter press in Tunlan coal preparation plant,the technical renovation was taken on the slime recovery system using KMZG450/2000-U quick-open diaphragm filter press and its auxiliary equipment.The paper introduces the structure,working principle and characteristics of the filter,and points out the operation essentials of filter.Production results show that,the process renovation by using KMZG450/2000-U quick-open diaphragm filter press,the problems of low efficiency and poor effect of dewatering are effectively solved,which created a certain economic benefits for the plant.