Abstract: The teeter bed separator and flotation column are preparation equipment for processing coal slime in coal preparation plants. The teeter bed separator are used for the coarse coal slime sorting. Because of the limits of principle, when the sorting particle size is big, the index will become worse. The floatation column do not recycle coarse coal slime by effect of bubble-particle desorption, and cost-recovering of flotation method is high. So through the development of a new gravity and floating coupling sorting machine in the success of coarse coal slime recovery, expanding sorting lower limit to reduce coal slime float content and the cost, gravity and floating coupling separator gathers high handling capacity and lowcost in one body.