Zirconia beads are made of micron and sub-nano zirconia and yttrium oxide as raw materials. They are used for ultrafine grinding and dispersion of materials that require "zero pollution" and high viscosity and high hardness. Mainly used in electronic ceramics, magnetic materials, zirconium oxide, silicon oxide, zirconium silicate, titanium dioxide, medicine and food, pigments, dyes, inks, special chemical industries.
There are many classifications of zirconia beads, but only the following are really suitable for grinding machines: yttrium stabilized zirconia beads, cerium stabilized zirconia beads, 80 zirconium beads and zirconium silicate beads. The zirconia content of yttrium stabilized zirconia beads is approximately 95%, so it is also commonly referred to as "95 zirconium" or "pure zirconia beads". It uses rare earth yttrium oxide as a stabilizer, and uses high-whiteness and high-fineness raw materials to ensure non-polluting materials. Such zirconium beads are suitable for sand mills. The zirconia content of the cerium stabilized zirconia beads is approximately 80%. The cerium stabilized zirconia beads have the highest density among all zirconium series of zirconium beads. Coupled with the characteristics of this type of zirconium beads, they are especially suitable for polishing. The zirconium oxide content of 80 zirconium beads is approximately 80%, so it is also commonly referred to as "80 zirconium". It has better grinding characteristics, making it highly cost-effective. It has been widely used in all walks of life. The zirconia content of zirconium silicate beads is approximately 65%, so it is also commonly referred to as "65 zirconium". The zirconium silicate beads are made by the advanced technology of titration in electrolyte and high-temperature firing and phasing. There are no pores and cavities in the beads. The medium density and hardness are suitable for the grinding of medium and low viscosity slurry.
Regarding the choice of zirconia beads, the popular glass beads, zirconium silicate beads and pure zirconium beads on the market are basically the electric melting method and the sintering method as far as the production process is concerned. Beads are formed in hot air, cold air or electrolyte. If a certain key technical parameter is not well controlled, fragile beads will be produced: bubble beads, snowman beads, tail beads, flat (elliptical) beads.
Because the above beads have stress concentration areas, they are easy to break during grinding. Therefore, when choosing beads, you should avoid such beads as much as possible. In addition, the zirconia beads are subjected to a pressure of about 1 kg under the normal operation of the sand mill. Compared with the glass beads which can withstand about 5000 kg of force and the zirconium silicate beads of 9000 kg, the zirconia beads are affected by the sand mill. The force is insignificant, so the cause of broken beads should be concentrated on the equipment and craftsmanship, and corresponding solutions should be adopted.
In summary, the reasons for the crushing of zirconia beads are mainly in two aspects: one is the quality of the beads themselves, which is a secondary reason; the other is the use of equipment and process parameters that are not suitable for such beads, which is the main problem. Therefore, it is necessary to fully understand its own equipment parameters and processes, and then choose the appropriate zirconia beads, in order to achieve the ideal grinding effect.
In terms of the correct use of zirconia beads, when we choose zirconia beads, how to use them correctly to avoid the crushing of zirconia beads and to extend the life of the grinding media and the contact parts of the sand mill as much as possible.
(1) Try to avoid turning on the grinder in a dry state, causing unnecessary loss of beads and accessories.
(2) Different brands or types of beads cannot be mixed.
(3) Try to avoid the mixed use of large and small beads.
(4) Zirconium beads are a kind of consumable. In order to protect the equipment and ensure a good grinding efficiency, it is necessary to check the center of the sand mill regularly and to screen and add the zirconium beads regularly.
