The 15 ml bowl of our Mini-Mill PULVERISETTE 23 can be filled with ~ 3 ml of activated carbon sample.
After 4 minutes of grinding, a fineness of < 25 µm has already been achieved.
Sample is not sticking so far, surfaces appear to be polished. A longer grinding time might still be possible, but the talk of < 100 µm is already reached. The grinding process has been aborted.
Also a grinding with Vibratory Micro Mill PULVERISETTE 0 is possible. With the grinding set of the Vibratory Micro Mill PULVERISETTE 0, also 5 ml can be ground in one batch.
With the lightweight grinding set (because agate uses to have a density of ~ 2,65 g/ml), it took about 10 minutes until the complete sample has been ground to < 100 µm.
We are guessing that a similar sample amount might get ground faster in zirconium oxide (with ~ 5,7 g/ml), steel (5,9 g/ml) or a grinding set made of hardmetal tungsten carbide (~14,9 g/ml).