The factors affecting the effect of heavy medium selection are mainly the nature of the suspension. In particular, the density, viscosity and stability of the suspension. The density of the suspension increases with the increase of the volume concentration of the suspended matter. When the volume concentration increases, the viscosity of the suspension also increases, which will increase the movement resistance of the ore particles, thereby making the sorting accuracy. And equipment production efficiency is reduced. Into the mineral crystal size more hours, the suspension should lower the viscosity required, to facilitate the mineral particles sorted quickly and accurately. Therefore, the concentration of the suspension should have a suitable range.