Effect of mechanical energy input on formation of flocculation in ultra-clean coal separation

In order to study the formation mechanism of flocculation by mechanical energy input in ultra-clean coal preparation process,the input of mechanical energy,which can overcome the energy barrier between coal particles to form flocculation,is investigated by using the extended DLVO theory to calculate the potential energy of fine coal particles and draw the potential energy curve. The effect of mechanical energy input on flocculation is confirmed by analyzing and calculating the formation of flocculation kinetic process. In order to test the reliability of the theoretical analysis part,the effect of mechanical energy input on the efficiency of the group was confirmed by using sedimentation experiment,the effect of mechanical energy input on the morphology of the flocculation was confirmed by using the optical microscope and the effect of different mechanical energy input on the quality of ultra clean coal was confirmed by using conventional flotation method. The conclusion is that the E_c increases rapidly with the increase of stirring speed when the speed changes from 500 r/min to 2 000 r/min and basically does not change when the stirring speed continues to increase. The structure of flocculation changes from loose to compaction with mechanical energy input and becomes loose chain after the overdose mechanical energy input destroying the structure of the flocculation. The highest yield and the lowest ash content of ultra-clean coal is found when the stirring speed reaches 2 000 r/min.