How to use zirconium beads correctly
How to choose the right grinding beads, after we choose the grinding beads, how to use it correctly, avoid the crushing of the grinding beads, and try to prolong the life of the grinding media and the contact parts of the sand mill are the issues we discuss together in this issue.
1. Reasons for broken beads: The popular glass beads, zirconium silicate beads and pure zirconium beads on the market are basically two kinds of electrofusion method and sintering method in terms of production process. The beads are formed in hot air, cold air or electrolyte. If some key technical parameters are not well controlled, the following fragile beads will be produced: bubble beads, snowman beads, tail beads, flat (oval) beads and above beads Because of the stress concentration area, it is easy to break during grinding, so when selecting beads, such beads should be avoided as much as possible.
2. Judgment of normal wear and tear of beads: Usually, the grinding beads that have been 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; In the case of odd-shaped beads, this should result in broken beads.
3. Reasons for broken beads: As far as the beads themselves are concerned, on the one hand, the quality of the beads is a problem, and on the other hand, the strength of the beads of this material cannot be better than that of a certain type of sand mill. For example, the Dyno-mill ECM horizontal sand mill in Switzerland and the DCP vertical sand mill in Drais in Germany are usually recommended to use pure zirconium beads due to the relatively high input energy density. In addition, under the normal operation of the sand mill, the grinding beads are subjected to a pressure of about 1 kg. Compared with the glass beads that can withstand a force of about 5000 kg and zirconium silicate beads of 9000 kg, the force of the grinding beads in the sand mill is It is trivial, so the reasons for broken beads should be concentrated on equipment and technology, and corresponding solutions should be taken.
Four, broken beads solution:
A. Equipment: Dispersing disc: Dispersing disc is reversely installed, loose or cracked; Separation device: There is a gap in the dynamic screen ring, and the screen is damaged; Feed pump: After the gear pump is suddenly turned off, the pressure in the sand mill will reverse the beads into the pump. It can be avoided as much as possible by installing a one-way valve, while maintaining regular cleaning of the feed pump; inner cylinder: the inner cylinder has defective points.
B. Production operation:
1. Mixed use of large and small beads: In this case, there is a sign of improving the grinding efficiency at the beginning, but as the grinding time increases, the situation of large beads grinding small beads occurs, and finally the deformation of the beads is accelerated and even broken. The solution is to try to use beads of uniform particle size.
2. Mixed use of beads of different brands: Due to the inconsistent hardness and density of various beads, it is easy to cause hard beads to eat soft beads, so this form should be avoided.
3. The viscosity of the slurry is too thin or too withered: Compared with the grinding beads of a certain density, it is easy to cause the accumulation of the beads and the direct contact with the wear parts of the sand mill to accelerate the wear and tear of the beads.
4. The flow of the material is too fast: This will cause the beads to accumulate at the material outlet, which will accelerate the wear of the beads and the accessories of the sand mill. The solution is to first loosen the backlogged grinding beads by intermittently starting the machine, and redistribute them evenly, and then adjust the flow of materials. Of course, there are other reasons for abrasive beads to wear and break.
