The Reason for The Decline in Cement Ball Mill Output

Recently, customers have reported that the output of cementgrinding has been at a relatively low level and has been declining. After technicalpersonnel surveyed and analyzed, based on experience and data, the reasons forthe decrease in cement ball mill output (increased energy consumption) wereanalyzed as follows.

Recently, customers have reported that the output of cementgrinding has been at a relatively low level and has been declining. After technicalpersonnel surveyed and analyzed, based on experience and data, the reasons forthe decrease in cement ball mill output (increased energy consumption) wereanalyzed as follows.

2. Poor ventilation. Due to the poor dust removal of the bagfilter, the severe fan blade wear, the loosening of the drive belt of the fanand the motor, and the accumulation of dust in the air pipe, etc., theventilation of the mill deteriorates, which causes a sudden drop in the outputof the mill table. Because the operator is concerned that the fineness of themilled cement will run out due to the increased ventilation, the ventilationoperation of the mill during grinding is conservative. At the same time, themoisture content of the material becomes larger, and the double-layered siloplate and the discharge core are blocked, affecting the ventilation inside themill. In some cases, the grinding head is also ashed due to clogging. Theoutput of the grinding table can be reduced by about 17%, and power consumptionincreased.

3. Into the mill material moisture increases. The moisture contentof the material directly affects the accuracy of the ingredients and the outputand power consumption of the mill. If the proportion of the wet material islarge, it may cause “saturation” or sticking of the inner liner to a thicklayer of material, forced to stop grinding.

4. The cement fineness index decreases. The decrease in thefineness index and the decrease in the average fineness immediately lead to adecline in the output of the mill. Under certain conditions, the output of theball mill is inversely proportional to the cement fineness.

5. Grinding body load is too small. The generally determinedloading volume allows for a certain range of fluctuations to accommodate theneed for more or less loading in the grinding volume addition cycle. In thisrange, the output of mills fluctuates little, but if the grinding bodies arenot added in time, when the load drops to a certain extent, the productionvolume at the station will drop significantly, especially in the firstposition. If the first warehouse load is reduced from 55 tons to 50 tons, themill's output will drop by more than 5 tons.

6. Grinding body silo. When the large gaps between the gas barrierplates or the connection screws of the jaws are broken, grinding of thegrinding bodies occurs. The grading of the grinding body after the silo wasdisrupted, and the grinding efficiency was greatly reduced. At the same time,the function of the partition board is also greatly weakened, and the cementfineness requirement must be met by reducing the amount of feed. Therefore, inthe event of a grinding body picking up, it should be promptly dealt with. Inaddition, in the clearance must be careful, can not be mixed with different diametergrinding body, otherwise, is to go to the role of clearance.

7. The clearance of the grinding body is not timely clearance isnot timely, the small size of the grinding body within the warehouse increased,the gradation has become extremely unreasonable, the average diameter droppedto a certain extent, can reduce the production of grinding mills 5% to 10%.

8. Pre-shredder system function decline. When the roller of theroller press wears to a certain degree, the crushing ratio of the roller pressis greatly reduced, and even if the circulating load of the disperser and theclassifier is high, the fineness of the material entering the grinding stilldoes not meet the ideal requirement. In addition, the mixed material and theclinker contain band-shaped debris, which is wound around the impeller of theclassifier, and the classification effect thereof is significantly reduced. Thecentral controller has to achieve the classification effect by increasing therotation speed, which inevitably leads to classification, grinding materialsize becomes larger.

9. Inspection is not in place. Including mechanical and electricalmaintenance inspection is not in place. Originally, some faults can be handledwithout stopping in the bud state. However, due to the inspectors' failure tofind them in time, the problems are serious, causing system congestion anddusting problems. They have to stop feeding or even shut down, resulting inincreased power consumption when the big station falls.