Abstract: According to problems existed in sizing equipment,process and separation size in the sized flotation process,using sieving analysis method combined with production condition,and assessed the industrial effect of the existing sizing equipment,investigated which separation size and sizing equipment is the most beneficial to give full play to the advantages of the sized flotation. The results show that: in the sized flotation process,if the coarse and fine particle size all further separation,the size of classification can be relatively vague,sieve bend and classifying cyclone can be used,but the classifying cyclone operations are more flexible and convenient; if coarse particle separated,it is will recovered rather than separation,the requirements of separation size are more stringent,the separation effect of the sieve bend is better,but the screen surface of the single arc screen is easy to appear the phenomenon of running water, can take two sieve bends used in series to reach higher security coefficient.