The floatation machine has the advantages of large air-absorption capacity and low energy consumption. Every cell owns three functions: air absorption, slurry absorption, and floatation separation, and the cells form a floatation separation loop by itself without any auxiliary equipment, and is allocated horizontally, which favors the change of flow. The circulation of mineral slurry is reasonable, and can avoid the disposition of coarse sand to the largest extent. There is self-control device on the surface of mineral slurry, so it is easy to adjust it. The impeller has backward-inclined upper and lower vanes, which produce upper and lower circulation of mineral slurrry respectively.