Abstract: To solve the problems of insufficient of lower limit of separation size in large diameter cyclone and the poor floatability of oxidized coal slime,the coarse slime separation process was added into the original separation process,which is the three product gravity-fed heavy medium cyclone plus flotation process in No.2 branch of Taixi coal preparation plant,while using the gravity separation process replaced the flotation process to recovery the oxidized coal.The production practice shows that after the modification,the problem of coarse slime lost in the process of flotation is significantly reduced in No.2 branch of Taixi coal preparation,realized the raw coal with the whole size fraction was separated and recovered efficiently.