If the feed pressure fluctuation is caused by the drop of the pump tank liquid level, it can be adjusted by increasing the liquid level, or closing one or two cyclones, or reducing the pump speed;  Judging whether the LUM ultrafine vertical mill is clogged is mainly determined by observing whether the overflow and underflow discharge of the LUM ultrafine vertical mill in operation are smooth.  When there are more coarse particles in the overflow, the flow of the overflow and the underflow is reduced, or the underflow is cut off, and the sediment is discharged in a columnar shape, it indicates that the LUM ultrafine vertical mill has been clogged.  In addition, if the LUM ultrafine vertical mill has a long period of violent shaking, it also indicates that the LUM ultrafine vertical mill is clogged. If the overflow and underflow flow are reduced, it may be that the feed port of the LUM ultrafine vertical mill is blocked.