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People in the industry know that the grinding means of bead mills mainly use glass beads, steel balls, zirconium silicate beads, zirconium beads, pure zirconia, etc. And the grinding medium is one of the important factors affecting the efficiency of the sand mill. So, faced with a wide variety of grinding media with different sizes, how to choose a suitable grinding medium has become the main problem for everyone to solve with zirconium beads manufacturer.
- The influence of the choice of zirconia beads on the grinding
(1) Hardness
Mohs hardness (Mohs) and Vickers hardness (Vickers) are commonly used indicators. Generally, the harder the zirconia beads, the lower the wear rate of the beads. Judging by the wear of the zirconia beads on the contact parts of the ball cutter (dispersion disk, rod pin and inner cylinder, etc.), the hardness of the zirconia beads will wear more on the contact parts, but the smooth surface of the beads will affect the cylinder and the cylinder. The wear of the dispersing disc is relatively small, and at the same time, it is possible to adjust the filling quantity of the grinding beads, the viscosity of the material, the flow rate and other parameters to obtain a better optimization point.
(2) Particle size
The size of the zirconia beads determines the number of contact points between the beads and the material. The greater the number of contact points of the beads with a small grain size in the same volume, the greater the effectiveness of collisions during the grinding process and the greater the grinding efficiency. tall. With the same grinding time, when using small diameter grinding beads, the fineness of the product is better than using large diameter grinding means. But on the other hand, when grinding materials with relatively large initial particles, such as 100 micron materials, pearls with D = 1mm may not be used because the pulse of the small pearls cannot reach the energy for a grind and sufficient dispersion.
(3) Density
Density is expressed in terms of density (true density) and bulk density (false density) in ordinary documents. The molecular weight and the percentage composition of the various oxides determine the density of the zirconia beads. Normally, the higher the density, the higher the density of the zirconia beads. Zirconium beads, the higher the kinetic energy generated by the rotation of the ball mill, the higher the grinding efficiency. But on the other hand, the higher the density of the grinding medium, the greater the wear of the contact parts (inner cylinder, dispersion disc, etc.) of the ball mill, hence the coordination of viscosity and flow rate of the material becomes the key.
(4) Reasonable fill rate
The filling speed of zirconia beads refers to the number of grinding beads required by the ball mill to achieve better dispersion and grinding effect. If the filling speed of the grinding beads is too high, it is easy to make the internal temperature of the ball mill rise, and the cylinder cannot radiate heat in time and automatically shut down. The filling speed of the grinding beads is too low, the grinding efficiency is low, and the average loss is large. Therefore, a reasonable fill rate is one of the important factors in improving the grinding efficiency. In the ball mill manual, the filling speed is often expressed by the volume measurement method, but in production it must be converted into the actual filling quality of the medium. Calculation formula = actual volume of the ball mill × filling rate × bulk density of the grinding medium.
2.Add grinding media
(1) The principle of replenishing the grinding media
If the grinding efficiency of the ball mill is reduced, beads can be added. Users can detect the actual bead loss rate according to their process conditions and perform regular sieving and beading addition.
(2) How to add grinding media
Due to the natural loss of the pearls, the particle size of the beads will become smaller and smaller. To maintain a uniform fill volume and prevent beads from clogging or entering the separation device, beads should be screened and supplemented based on the life of the grinding medium and the user’s process conditions. The amount of grinding means. Shanghai Root’s suggestion is to check the bead wear after 500-600 working hours and add a reasonable amount of new beads.
