graphite

Even after 20 minutes of dry grinding sample did not start sticking. Grinding has been interrupted and fineness has been determined by our Laser Particle Sizer ANALYSETTE 22 compact.

Longer grinding times are plausible, but graphite can be used as dry lubricant. For this, we are guessing that fineness use to rise slowly.

By using ruff surfaced sintered corundum, only a fineness of 41% < 45µm has been achieved after 20 minutes of grinding. For this, sintered corundum is not recommended as grinding material for graphite.

Probably a grinding with Variable Speed Rotor Mill PULVERISETTE 14 might be able to achieve a good grinding result (see following trials).

We recommend pre grinding the sample with coarse sieve rings (like the used one in this trial) for a much longer durability of fine sieve rings.

It took about 1 minute for feeding the complete sample to the machine. Afterwards, majority of ground particles use to be way finer as 1mm. Following step (result 4) will show fine grinding trial.

Sample has to pass smaller openings, when the arrow (printed on sieve rings) will point downwards.

After 2 minutes of grinding, sample fineness has been detected with 96,6 % < 45µm.

Probably escaping dust by the feeding funnel can be minimized by using the accessories for grinding large quantities and surely will be avoided if the optional active sample exhauster system with cyclone separator will be used.