Study on principle of selective crushing and separation of coal and gangue

Selective crushing is an effective method to achieve the separation of coal and gangue.By study the size effect of coal and gangue’s mechanics parameters,and use the exponential function to fit various mechanical parameters,then acquire the rock’s mechanics parameters under different grain diameter.Making calculation to the crushing speed of coal and gangue by the formula of,then can get the speed range of impact grinding about coal and gangue in different kind.Simultaneously,when there is almost no coal rock in raw coal,selective crushing can be used to the separation of coal and gangue.If there is far more diverse of coal and gangue’s physical-mechanical properties,the effect of selective crushing will be better.