No grinder can beat the speed of a Vibratory Disc Mill when it comes to preparing samples for spectral analyses. RETSCH’s Vibratory Disc Mill RS 200 is ideally suited for fast and reproducible pulverization of hard, brittle and fibrous sample materials to analytical fineness.
The RS 200 runs steadily and smoothly, even with heavy grinding sets and at maximum speed thanks to its powerful Stabilized-Plane-Drive. It achieves grind sizes between 20 and 100 microns within seconds and with excellent reproducibility.
Grinding sets are available in a variety of sizes and materials. A set of sensors will recognize jars of tungsten or agate and automatically sets the maximum permissible speed, ensuring optimum results while protecting the material.
The grinding results of a vibratory disc mill are significantly influenced by the movement patterns of the free masses inside the grinding jar. The new, powerful Stabilized-Plane-Drive of the RS 200 allows for extremely rapid formation of the movement pattern which is reflected in higher fineness and ultimately leads to significantly better reproducibility.
Figure 1 shows the standard deviation after 60 sec grinding time. It only takes a few large particles to impair the reproducibility of XRF measurements. Because of that, a small standard deviation for the d90 value is crucial.
Fig. 2: A “Quarter Minute Test” (QMT) evaluates the formation and stability of the movement patterns of Vibratory Disc Mills. Figure 2 shows that with the RS 200 a d90 value of 106 μm was obtained after a grinding time of only 15 seconds. The mills from three other manufacturers showed considerably inferior results.
Grinding parameters
To ensure accurate and reproducible XRF analysis results, the sample needs to have a uniform particle size distribution and the pellet to be pressed needs to be as dense as possible. Both requirements are easily met when using our vibratory disc mills and pellet presses for sample preparation to XRF analysis.
| Applications | size reduction, mixing, triturating |
| Field of application | construction materials, environment / recycling, geology / metallurgy, glass / ceramics |
| Feed material | medium-hard, hard, brittle, fibrous |
| Size reduction principle | pressure, friction |
| Material feed size* | < 15 mm |
| Final fineness* | < 20 µm |
| Batch size / feed quantity* | 15- 250 ml depending on size of grinding set |
| Speed at 50 Hz (60 Hz) | 700 - 1,500 min-1, continuously adjustable |
| Material of grinding tools | hardened steel, tungsten carbide, agate, zirconium oxide, steel 1.1740 (for heavy-metal free grinding) |
| Grinding jar sizes | 50 ml / 100 ml / 250 ml |
| Setting of grinding time | digital, 00:01 to 99:59 |
| Storable SOPs | 10 |
| Drive | 3-phase asynchronous motor with frequency converter |
| Drive power | 1.5 kW |
| Electrical supply data | different voltages |
| Power connection | 1-phase |
| Protection code | IP 20 |
| W x H x D closed | 836 x 1220 x 780 mm |
| Net weight | ~ 225 kg (without grinding set) |
| Standards | CE |
*depending on feed material and instrument configuration/settings
