Vanadyl Pyrophosphate

Because of the limited amount of sent sample, only 80 ml bowl needs to be used for grinding. For higher amounts, up to 500 ml grinding bowls use to be available.

After the first minute of dry grinding, sample is already < 80 µm as desired. Because sample did not start sticking yet – even longer dry grinding times are possible (see result 2).

After 2 minutes of dry grinding, sample starts sticking lightly to bowl and grinding balls.

This uses to happen after the majority of particles reached a fineness of < 20-30 µm. Interacting forces between fine ground particles will become bigger as their own g-force. Therefore, particles will stick to each other and become compressed by the used grinding balls. These clusters of particles also contain bigger particles which will not be ground any further.

For this, not much longer dry grinding time are possible to reduce the particle size any further. We recommend proceed grinding in suspension, if further comminution will be preferred.

The present fineness after 2 minutes of dry grinding use to be < 40 µm.