How to use grinding beads correctly?
It is mentioned above that how to select the appropriate grinding ball, and after we select the grinding ball, how to use it correctly, avoid the breakage of the grinding ball and prolong the service life of the grinding medium and the contact parts of the sand mill as much as possible are the issues we discuss together in this period.
1、 Causes of broken beads: glass beads, zirconium silicate beads and pure zirconium beads are popular in the market. In terms of production process, they are basically electric melting method and sintering method. Beads are formed in hot air, cold air or electrolyte. If a key technical parameter is not well controlled, the following fragile beads will be produced: 1. Bubble beads 2. Snowman beads 3. Tail Beads 4. Beads above flat (oval) beads are easy to break during grinding due to the stress concentration area. Therefore, such beads should be avoided as much as possible when selecting beads.
2、 Judgment of normal wear and breakage of beads: generally, the grinding beads working for a period of time become smaller, and the surface is smooth without edges and corners, which should be the wear of normal beads; On the contrary, if there are angular and flake shaped beads in the beads, it should be broken beads.
3、 Causes of broken beads: as far as the beads themselves are concerned, on the one hand, it is the quality problem of the beads, on the other hand, or the strength of the beads of this material cannot be better than that of a certain type of sand mill. For example, dyno mill ECM horizontal sand mill in Switzerland and DCP vertical sand mill in Drais, Germany usually recommend the use of pure zirconium beads because of the high input energy density. In addition, under the normal operation of the sand mill, the grinding beads are subjected to a pressure of about 1kg. Compared with the glass beads that can bear a force of about 5000kg and the zirconium silicate beads of 9000 kg, the stress of the grinding beads in the sand mill is insignificant. Therefore, the reasons for the broken beads should focus on the equipment and technology, and corresponding solutions should be taken.
4、 Solution to broken beads:
A. Equipment 1 Dispersion plate: the dispersion plate is installed reversely, loose or cracked. 2. Separation device: the dynamic screen ring is notched and the screen is damaged. 3. Feed pump: after the gear pump is suddenly turned off, the pressure in the grinder will back press the beads into the pump. It can be avoided as far as possible by installing a one-way valve, while maintaining regular cleaning of the feed pump. 4. Inner cylinder: the inner cylinder has defects.
B. Production operation: 1 Mixed use of large and small beads: in this case, there are signs to improve the grinding efficiency at the beginning, but with the extension of grinding time, there is the situation of large beads grinding small beads, and finally accelerate the deformation and even crushing of small beads. The solution is to try to use beads with uniform particle size. 2. Mixed use of beads of different brands: due to the inconsistency of hardness and density of various beads, it is easy for hard beads to eat soft beads, so this form should be eliminated. 3. The viscosity of the slurry is too thin or withered: compared with the grinding beads with a certain density, it is so easy to cause the accumulation of beads and direct contact with the wear parts of the sand mill to accelerate the wear and breakage of beads. 4. The flow of materials is too fast: this will cause the backlog of beads at the material outlet and accelerate the wear of beads and sanding mill accessories here. The solution is to loosen the backlog of grinding beads by intermittent start-up, redistribute them evenly, and then adjust the flow of materials. Of course, there are other reasons for the wear and breakage of grinding beads. You are welcome to have extensive exchanges with Burris on this issue.
