Dry and wet grinding
For nano-powder manufacturers, of course, it is desirable to obtain the final nano-powder by dry grinding. However, if the powder is ground by mechanical grinding, during the grinding process, the temperature of the powder will rise rapidly due to the introduction of a large amount of energy, and when the particles are miniaturized, it is difficult for the grinder to control how to avoid explosion-proof problems.
So in general, the particle size of dry grinding can only be ground to 8μm. Wet milling is necessary to obtain a particle size of 8 μm or less.
The so-called wet grinding is to first mix the nano powder with an appropriate solvent to prepare an appropriate material. In order to avoid powder agglomeration during the grinding process, it is necessary to add appropriate dispersants or auxiliary agents as grinding aids.
If the final nano-scale product is expected to be a powder rather than a slurry, it is necessary to consider how to filter the large particles in the slurry and how to dry the filtered slurry to obtain a nano-scale powder.
Therefore, when the nano-scale powder is obtained by wet grinding, how to choose the appropriate solvent, auxiliary agent, filtration method and drying method will affect whether the key technology of nano-scale powder can be successfully obtained.
Dry grinding generally uses a ball mill or a ball mill, and zirconia beads use larger balls, such as 5, 6, 8, 10, 15, 20mm and other zirconium balls.
In the bead mill used for wet grinding, it is necessary to determine the size of the zirconia beads according to the initial particle size of the material and the final fineness of the grinding.
