Aluminum - foil

Especially ductile metals are hard to grind, finer particles as produced by rasping are hard to grind (usually ductile metals just deform).

We also like to mention that fine ground metal particles can ignite or start burning. For this, our trials we performed have been prepared slowly with proper safety equipment (googles, coats, cloves, etc.).

The sample pieces have been fed within 5 minutes. Usually sample which will be ground with Variable Speed Rotor Mill PULVERISETTE 14 uses to have a size of ground particles, smaller as half of the diameter of the trapezoidal openings of the used sieve ring.

We also checked the weight of the used sieve ring before and after grinding. Because this sample use to be very ductile and might get ground mainly by shearing force, the sieve ring might show higher abrasion. In this case, we found about 30 mg of weight loss by each 10 g of sample we fed.

For demonstration, we will also try grinding the rest of sample with a 0,2 mm sieve ring (see result 2).

Standard comments of result 1 also use to count for this trial.

The remaining 10 g of sample got fed and ground within 3,5 minutes. Openings of the used sieve ring remain free of residues, no clogging of the openings has been observed. Even higher amounts of sample can be fed this way.

After 10 g of sample got ground, we found a weight loss of 0,05 g on the sieve ring which uses to be a loss of ~ 0,1 % of material.