How often should the grinding medium of the tube mill be changed?

The replacement cycle of the grinding medium of the tube mill is not fixed, and it is affected by a variety of factors.
First, the wear of the grinding medium
Grinding media will gradually wear out in the process of constantly impacting and grinding the material. The degree of wear depends mainly on the hardness of the material being ground. For example, if it is a very hard grinding ore, such as quartz stone ore, the wear rate of the grinding medium will be faster. In general, when the diameter of the steel ball is worn more than a certain proportion of the original diameter (such as 50%-60%), its grinding efficiency will be greatly reduced, and it needs to be replaced. Because the mass of the grinding medium becomes smaller after wear, when the cylinder rotates, its lifting height and impact energy will be reduced, and the material can not be effectively crushed.
Second, production efficiency requirements
If there are high requirements for the output and quality of the product, when the grinding medium wears to a certain extent, resulting in reduced grinding efficiency, can not meet the production plan of the output requirements or product particle size does not meet the standard, the grinding medium should be replaced. For example, in the production of cement, it is necessary to grind the cement clinker into a specific particle size of fine powder, if the grinding medium wear, the production of cement powder particle size coarser, does not meet the quality standards, in order to ensure product quality and production efficiency, it needs to be replaced in time.
Third, the material and quality of the grinding medium
Grinding media of different materials have different service life. Grinding media made of high-quality alloy steel are usually more wear-resistant and have a longer service life than those made of ordinary carbon steel. If a good quality grinding medium is used, the replacement cycle may be relatively long. For example, the use of special heat treatment process of high chromium alloy steel balls, its hardness and wear resistance are very good, under the same grinding conditions, compared with ordinary steel balls, its replacement cycle may be extended 1-2 times.
Four, the operation parameters of the tube mill
The operating parameters such as the rotating speed of the cylinder and the filling rate of the material will also affect the service life of the grinding medium. If the cylinder speed is too high, the impact force of the grinding medium is too large, which may lead to the crushing and excessive wear of the grinding medium; The speed is too low, the grinding medium can not give full play to its grinding effect, but also affect its service life. In addition, the material filling rate is too high will reduce the chance of collision between the grinding medium and the material, reduce the grinding efficiency, and may also accelerate the wear of the grinding medium.
In summary, the replacement cycle of the grinding medium of the tube mill varies due to material hardness, production efficiency requirements, material quality, operating parameters and other factors, which need to be comprehensively judged according to the actual production situation and equipment operating status. In general, continuous operation for several months to several years may require the replacement of grinding media.