The density of specific gravity liquid is calculated, and the floating and sinking test only measures the density composition of your raw coal. When measuring the recovery rate of raw coal in the laboratory, you should first know the ash requirement of clean coal, then calculate the density of specific gravity liquid according to the data in your own raw coal "screening flotation table", and you can also calculate your recovery rate of raw coal. The "raw coal recovery rate" you mentioned above is not correct, but "clean coal recovery rate".