At present, the concentration of flotation slurry in coal washing plants in China is generally between 10% and 15%. Although using low concentration flotation can achieve good flotation indicators, it is not necessary to use low concentration flotation for various properties of coal slurry. Therefore, the selection of slurry concentration should be based on the properties of the coal slurry. The slurry concentration can be determined during the production process based on the following conditions:

　　1. Under the premise of production indicators, try to increase the slurry concentration as much as possible, so that all conditions are in the best state for flotation.

　　When flotation coal slurry with good coal quality and low ash content, a higher slurry concentration can be used. For coal slurry with high ash and fine mud content, the slurry concentration should be appropriately reduced.

　　When flotation of fine-grained coal slurry, a lower slurry concentration should be used, while flotation of deslimed coal slurry can use a higher slurry concentration.

　　4. For flotation machines with high inflation capacity, the slurry concentration can be appropriately increased when processing coal slurry with low fine mud content.

　　5. In flotation processes with selection, higher slurry concentrations can be used for rough selection, while lower slurry concentrations should be used for selection.