1. The ph value of the slurry
The pH value of the initial refining is 5.25. After 20 hours of grinding, the ph of the refining using zirconium beads is 5.78, and the ph of the refining using glass beads is 10.22
It can be seen that the use of zirconium beads can avoid a significant increase in the pH value of the dye refining, and this increase in the value will bring different degrees of negative effects on the further processing and future applications of the dye. Because of its chemical composition, high strength and wear resistance.
2. The viscosity of the refining
After a long time of grinding, we found that the viscosity of the slurry ground with glass beads has a very significant increase. Under the same grinding conditions, its viscosity is increased by 1 to 4 times that of zirconium beads.
The increase in the viscosity of the grinding slurry is mainly due to the evaporation of the water in the grinding slurry caused by the heat generated during the grinding. The establishment of the grinding dispersion system and the wear of the grinding medium (such as glass beads or zirconium beads) into the grinding slurry cause disperse dyes In the grinding process of vat dyes and vat dyes, the increase in the dryness of the grinding with a certain solid content will not be conducive to the kinetic energy transmission of the grinding medium and will significantly reduce the grinding efficiency.
3 beads stain
When the dye is being ground, it will stain its grinding media. In production and testing, the ideal grinding media should be stained as little as possible. The absolute value of this performance is very different for different dyes. However, if you use several dispersed dyes and glass beads and zirconium beads to grind separately, the glass beads and zirconium beads are washed and dried with water after complete grinding, and then the quantitative glass beads and zirconium beads are treated with acetone to measure the optical density value of the acetone solution. Compare. We can find that the staining of glass beads is 15 ~ 30 times that of zirconium beads. . This application characteristic of zirconium beads is also due to its high mechanical strength and smooth surface.
4 Wear of beads
Under normal grinding conditions, zirconium beads and glass beads are used as grinding media. After the grinding is completed, the weight loss percentage of the grinding media is measured to evaluate the wear of the beads. After many experiments, we found that the wear rate of zirconium beads is less than 1/5 of that of glass beads.
The wear of the beads not only increases the production cost. It also increases the chemical composition, high strength and abrasion resistance of the ash in the dye.
5 Grinding efficiency
Compared with glass beads, zirconium beads have the characteristics of higher density and higher strength. In our application, we found that for the high solid content and viscosity of the grinding slurry, the use of zirconium beads can significantly improve the grinding efficiency; at this time, the use of glass beads will significantly reduce the grinding efficiency, increase the grinding time, and sometimes even make it Grinding cannot be done.
6 Grinding effect
The purpose of the grinding process for dispersing and vat dyes is to obtain dyes with particle diameters between 0.2 and 0.8 um. We used zirconium beads and glass beads in the experiment and found that the particle distribution of the dye was much better than that of glass beads when grinding with zirconium beads.
