Zirconium (raw material)

Small quantities as this can be placed into a plastic bag and hit with several strokes of a hammer for pre crushing.

Also the Jaw Crusher PULVERISETTE 1 Model I can be used. Within 1-2 seconds, the 12 g of sample have been ground to a maximum length of 5 mm.

Grinding chamber is only lightly polluted, a grinding of higher amounts is still possible. Cleaning can be done rapidly by vacuuming with a soft brush.

Sample which has been prepared like this can be fine ground in planetary mills or ball mills like our Mini-Mill PULVERISETTE 23 (see following trial).

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

This uses to happen after the majority of particles reached a fineness of d50 < 20 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.

Coarse particles can be ground further after separation (e.g. by sieving or sifting). So no fine particles are present which will become compressed by the grinding balls. Also a further grinding of the total sample amount in suspension is plausible for a further size reduction.