Considering the characteristics of materials used for the construction of a cell phone the whole spectrum of hard-tough to hard-brittle up to soft, tough-elastic materials is found. Mentioned should be metals, ceramic parts and the most various plastics.
Whereas the hard-brittle materials are easily ground with impact energy, the comminution of tough-elastic materials is only achieved with cutting force. Tough-elastic materials may be embrittled with liquid nitrogen and then ground with impact force.
The Universal Cutting Mill PULVERISETTE 19l/50-700 rpm was chosen as the first level of comminution of a complete cell phone. Once reduced to 10 mm the Vibrating Cup Mill PULVERISETTE 9 was supposed to complete the rest. This experiment was unsuccessful. Therefore the PULVERISETTE 19 large with 50-700 rpm and a 4 mm sieve was used again. For the next level, the Universal Cutting Mill PULVERISETTE 19 was chosen. With cutting tools made of hardmetal tungsten carbide the remainder was comminuted down to 1 mm. An attempt to achieve even a finer powder by exchanging the sieve was unsuccessful. That’s why as the last level of comminution the Variable Speed Rotor Mill PULVERISETTE 14 classic line with a 0.5 mm sieve was utilized.
Good experiences of the comminution of single electronic components were made with the Vibratory Micro Mill PULVERISETTE 0, embrittled with liquid nitrogen in the cyro-box.