It has the following characteristics: large inspiratory capacity and low power consumption. Each tank has three functions of suction, suction and flotation, self-forming flotation circuit, no need for any auxiliary equipment, horizontal configuration, easy to change the process. The slurry circulation is reasonable, which can minimize the coarse sand sedimentation. It has a self-control device with a slurry surface for easy adjustment. The impeller has a rearward inclined upper and lower blades. The upper blade produces a slurry circulation, and the lower blade produces a slurry circulation.