|< 250 µm|
|d90 < 10µm|
|We recommend using a planetary ball mill like our Planetary Mill PULVERISETTE 5 classic line for a grinding of higher amounts.|
main disk speed: 360 rpm
250 ml grinding bowl made of zirconium oxide (ZrO2)
+ 50 x 10 mm Ø zirconium oxide grindingballs
||< 250 µm|
||+ 40ml water|
||97.4% < 10 µm|
For 100 g of sample (as provided), bowls of 250 ml volume use to be fulfilling for grinding. Higher amounts can be ground with maximum 500 ml girnding bowls (with up to 4 bowls fasteners at PULVERISETTE 5).
To avoid over pressure, we ground the sample in steps of 5 minutes, followed by a programmed pausing time of 10 minutes. After several cycles, the outside temperature of the bowl should be checked (remain below 80°C); grinding time or programmed pausing time might be readjusted afterwards.
By using 10 mm Ø grinding balls, balls don’t need to be changed during grinding to fulfill the desired fineness of d90 < 10 µm. After a total grinding time of 2 hours. The desired fineness has been achieved.
It is plausible that the total grinding time can be reduced, when grinding balls will be changed after a pre grinding with 10 mm Ø balls (e.g. for 15 minutes) to 2 mm Ø. Because of the higher amount of girding balls, grinding will be improved. We recommend using balls which use to be 20x bigger as the present particle size.