This invention is mainly for the processing of the cyclone settled sand or other coarse and highconcentration materials in the nonferrous and gold mines. SS2.5 flash flotation cell developed by CINF is applicable for the mediumsize and small mines to process cyclone settled sand or other coarse and highconcentration materials. The different minerals are separated out selectively in the flash flotation cell by agitation, dispersion and aeration to realize complete mixing of the slurry and air through air dispersion to the liquid. Hydrophobic layer is formed selectively on the flotation particles through the chemical reagent. Innumerable air bubbles are generated during the air and liquid mixing. The hydrophobic particles are adhered on the air bubbles and carried to the liquid level before scrapped.