More crushing and less grinding will reduce the grinding particle size of the ore milling plant. The larger the grinding particle size, the greater the work done by the ore milling plant on the ore, and the grinding efficiency of the ore milling plant will naturally be affected.

In order to achieve qualified grinding fineness, the workload of ore milling plant is bound to increase and the energy consumption will also increase.

To reduce the feeding particle size, it is required that the particle size of crushed products is small, that is, "more crushing and less grinding".

In this way, the feeding particle size is appropriate, and the grinding efficiency of ore milling plant will be improved.

This method can improve the chemical reaction activity of roasted products, greatly improve the whiteness of calcite, and obtain high-grade calcite grinder milling plant machines.

However, the disadvantage of roasting purification is high energy consumption and easy to cause environmental pollution.

It is difficult to obtain high-grade calcite grinder milling plant machines only through a single process.

Therefore, in the actual production, it is recommended that the mine owners select qualified manufacturers for beneficiation test, and adopt a combination of multiple processes to improve the product quality of calcite.

Magnetic separation mainly uses the magnetic difference between gangue minerals and silica sand to remove these colored impurities. Magnetic separation is more effective for magnetite, ilmenite and other strong magnetic minerals or iron filings mixed in the processing process.

For weakly magnetic minerals, there are two main methods: one is roasting to turn the minerals into strong magnetic iron oxide, and then grinding; Another method is to use high gradient and strong magnetic field grinding method for grinding.

Because the silica sand grinding method does not need to use chemicals and will not pollute the environment, it is widely used in the process of non-metallic beneficiation.

The grinding method has effectively solved the problem of the development and utilization of low-grade silica sand that does not have commercial mining value due to the high content of iron ore.

This phenomenon is mainly due to the small feeding particle size, short residence time of ore in the ultrafine vertical mill and fast speed. 

It should be noted that when the grinding products are required to be coarse, the variation of mill productivity with feed particle size is obvious, while when the grinding products are required to be fine, the variation of mill productivity with feed particle size is not very prominent. 

When the feeding particle size, i.e. the grinding particle size, is small, the grinding fineness is easy to achieve. However, the fineness and productivity are contradictory. 

Under the condition of the same feed particle size, the production capacity of the mill decreases with the increase of the fineness of grinding products.

Poor lubrication includes improper lubricant selection, improper filling amount or oil level of grease, deterioration of oil (grease) or lack of oil (grease).

1) The selection of lubricant and lubrication method are unreasonable

The rolling bearing of vertical roller mill lubricant shall be selected according to the bearing operating temperature, speed index, load characteristics, lubrication mode and other factors. If the lubricant is improperly selected and the viscosity is too low or too high, it is difficult to form oil film, which will make the heat generated during bearing operation unable to be taken away and cause bearing heating.

2) Improper amount of oil (grease)

Too little or too much oil (grease) will cause fever due to lack of oil or too much oil and large stirring.

3) Failure to change oil on time, deterioration of lubricating oil and impurities such as iron filings in lubricating oil lead to deterioration of lubrication condition.

4) The bearing is short of oil, hot and invalid due to oil leakage of vertical roller mill bearing seat and other reasons.

The thermal expansion of the inner ring will lead to the looseness of its fit with the journal, while the thermal expansion of the outer ring will lead to the tightening of its fit with the shell hole, which will lead to bearing heating.

The wear of ore milling plant bearing is the most important fault in the use of ore milling plant bearing. Continuous wear will change the size of inner ring, outer ring, rolling element and cage of ore milling plant bearing, and even produce pitting or peeling.

The matching clearance of ore milling plant bearing will increase and the surface roughness of running elements will increase, which will reduce the running accuracy of ore milling plant bearing and therefore the running accuracy of machine, Thus, the temperature, vibration and noise of the bearing will increase. In serious cases, it will lead to heating, vibration, bearing burning and even shaft bending.

At present, the selection range of unit output of vertical roller mill on the market is large, ranging from 10 tons to hundreds or even thousands of tons.

Therefore, the mine owner needs to choose what type and model of LM vertical roller mill to be used according to the specific output requirements of the concentrator, and how to arrange the milling process is more reasonable, so as to achieve a good investment rate.

In addition to the above four objective factors, Zenith mechanical design experts also suggest that when choosing LM vertical roller mill, the mine owner should choose a formal and well-known equipment manufacturer.

At present, there are many manufacturers of vertical roller mill in the market, and the equipment is also a mixture of good and bad.

In milling grinding operation, grinding operation is far more than milling operation in terms of production cost, infrastructure investment and power consumption. According to statistics, the unit energy consumption of grinding operation is up to 5 times that of milling operation, accounting for about 85%.

With the continuous development of beneficiation technology, the LM vertical roller mill team on the market is also growing, with countless types and models, such as the common jaw vertical roller mill, hammer vertical roller mill, counterattack vertical roller mill, conical vertical roller mill, mobile vertical roller mill, counter roll vertical roller mill, etc.

In addition, the working principle of each vertical roller mill is different, and the suitable range is also very different, which undoubtedly increases the difficulty of selecting vertical roller mill.

The aged and unusable screen surface shall be replaced in time to avoid more serious problems. The above are the five common problems of vertical roller mill, causes and countermeasures.

In order to ensure the stable and efficient operation of the equipment, in addition to selecting the type of equipment in line with the beneficiation process, daily maintenance and repair are particularly important.

Therefore, it is suggested that the mine owners consult the professional equipment manufacturers when selecting the vertical roller mill, and select the equipment suitable for their own process flow, so as to fundamentally ensure the normal operation and economic benefits of the whole concentrator.