At a particle size of less than 20 µm, the surface forces prevail. The
grinding stock begins to stick.
Additional dry comminution can be achieved by adding surface-active
substances to the material to be ground.
Examples (maximum amount to be added in mass %)
n
Stearic acid 2-3 %
n
Aerosil (fine-particle silicic acid) 0.5 - 2 %
n
Quartz sand ~ 2 %
n
Glass powder ~ 2 %
n
Glycol (Ethylene glycol) ~ 0.1 - 0.5 % (
≙
5 - 25 droplets)
n
Triethanolamine ~ 0.1 - 0.5 %
6.4.7 Wet grinding (grinding in a suspension)
DANGER!
Explosion hazard! Ignition hazard!
The device is not explosion-protected. If flammable liq-
uids are used, make sure that the heat developing in
the grinding bowl (outer wall max. 80 °C) does not
reach the solvent's boiling point. Program appropriate
cooling phases. If the vapour pressure is too high,
vapours may escape and ignite. If it can be avoided, we
recommend using non-flammable liquids or liquids with
a high boiling point. The boiling point should be
above100 °C.
Achten Sie während einer Nassmahlung auf eine ausrei-
chende Viskosität. Vor allem bei einer längeren Mahl-
dauer ist eine eventuelle Nachjustierung erforderlich.
When changing over to grinding in suspension, you can add liquid auxil-
iary agents with a high boiling point and low vapour pressure, e.g. water,
white spirit (boiling point 100 - 140 °C) or high-boiling alcohols (e.g. glyc-
erine).
We recommend that you only use so much liquid that the suspension,
including the balls, has the same consistency as engine oil. With this vis-
cosity the best results can be achieved in most cases.
Using the device
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