Cement ball mill overgrinding reasons

Cement ball mill overgrinding is abnormal phenomenon occurs at the time of its work, due to the large quantity of materials or excessive moisture, the material in the body so that the flow rate of the cement tube mill is too slow, or due to blockage inside the warehouse, excessive accumulation of raw materials cause. On the surface there are the following forms: sound boring, the current decline, lower production, comb joints blocked raw materials, raw material adhesion on a large number of grinding and liners. Concrete manifestation is: when the overgrinding is lesser extent, cement ball mill sound turned low, the quantity decreases, import and export pressure increases; saturation degree mill is more serious, the sound disappears, a significant reduction in the current of the main motor, the quantity greatly reduced; saturation degree mill is particularly serious when ball mill don't expected, a sharp increase in negative pressure.

Cement mill overgrinding is due to the loss of balance, resulting in excessive quantity of memory mill, indirect causes are the following:
1, the volume of feed too much material into the mill or larger size, hardness becomes large, there is no time to reduce feeding, not a lot of broken guessed sandwiched diaphragm plate grate cracks, diaphragm plate blocked, so that the material can not be discharged ;
2, material into the mill water is too large, and poor ventilation, you can not bring water vapor and fine materials and when the ball outside, so that the material due to humidity and adhere to the lining of the surface of the ball, reducing the grinding efficiency, and because increased wet material, so that the flow rate slows down, causing the discharge due to difficulties;
3, ball gradation unreasonable, too small ball, the ball diameter is too small or average fill rate is too low, resulting in reduced grinding action;
4, feed back too much and does not reduce the volume of feed, causing blockage;
5, the diaphragm plate grate sew or clogged debris, causing small holes grate full mill.

For the cement mill overgrinding reasons, take a relatively saturated mill processing method, as follows:

1, prior to the former feed once broken, is placed in front of a cement mill efficient crushing machine, entering cement mill feed particle size reduction, the original coarse grinding compartment is handed over to a more professional and more efficient to efficient crushing machine carry out.
2, pre-grinding (mainly equipment with short ball mill, roller mill, roller press, roller mill, etc.).
3, to reduce the volume of feed, if the effect is not obvious, you need to immediately stop feeding, so that the ball mill operation in less material or non-material under to produce more heat, water evaporation, thereby reducing the sticky ball and diaphragm plate clogging;
4, stop feeding in the case, adding to the mill grinding materials (raw mill plus dry coal or lime, slag cement mill plus dry or dry slag), to be close to normal grinding sound, feeding a small amount of material, then gradually increase the volume of feed, until the normal feed.
5, increase the mill ventilation, so that fine material is discharged as soon as possible, while observing the main motor the current is increased, if the current is increased, indicating full grinding phenomenon has been eliminated, then you can gradually increase the volume of feed.
6. If the above two methods ineffective, they have to shut down, open the door to check the grinding compartment plate and grate plate to see if the blockage;

When ball mill overgrinding, mill stopped only as a last resort, because when it overgrinding, the load of ball mill became larger, once shutdown in tne overgrinding,could lead ball mill can not be started.
Stop grinding down approach: pour the ball and silo within the liner and completely chipped the ball on the crust, remove diaphragm plate grate sew obstruction, and then re-loaded with the ball or the ball poured .