potassium chloride (KCl)

Sample starts sticking very fast. After only 1 minute of dry grinding time, sample is sticking lightly to bowl and grinding balls. A longer dry grinding time is not recommended.

When majority of particles reached a fineness of < 20-30µm. Interacting forces between fine ground particles will become bigger as their own g-force. Therefore, particles will stick to each other and just become compressed by the used grinding balls. These clusters of particles also contain bigger particles which will not be ground any further too. With hygroscopic sample like KCl, sticking might occur even earlier.

To determine the fineness after 1 minute of dry grinding, an aliquot has been used for sieving with our Vibratory Sieve Shaker ANALYSETTE 3 Pro. It has shown, that 100% of sample use to pass even 400µm mesh test sieves.

Desired fineness has b

een reached. If a better endfineness as < 400µm should be achieved, only a grinding in suspension will be plausible with a planetary mill.

Comments of result 1 use to count for this trial as well.

By using grinding balls and bowl made of stainless steel instead of zirconium oxide, grinding result cannot been improved. Also sticking of sample use to start after particles have been ground to < 400µm.

To improve the dry grinding result, it is possible separating fine ground sample which will start sticking by sieving or sifting and only proceed grinding the coarse particles.

If a better endfineness is desired, also a grinding in suspension is plausible.