CAUTION!
The grinding element is subject to normal wear during
use. Before every grinding operation, check the wall
thickness of the grinding bowls. In the event of severe
wear, replace the grinding bowl. If this is not done, the
prevailing high centrifugal forces during grinding may
cause the grinding balls to penetrate the bowl's wall
and damage the mill. Failure to observe this will render
void the guarantee and release us from liability for any
resulting damage to the device or personal injury.
The hardness and density (specific weight) of the grinding bowl and
grinding balls used must be greater than that of the material used, to
prevent excessive wear by abrasion.
Material
(bowl and balls)
Main components of
the material
Density in g/cm
3
High density means
high impact energy!
Abrasion resistance
Use for grinding
stock
Agate
(99.9% SiO
2
)
2.65
Good
Soft to medium-hard
samples
Silicon nitride
(90% Si
3
N
4
)
3.25
Extremely good
Abrasive samples,
metal-free grinding
Sintered corundum
(99.7% Al
2
O
3
)
3.9
Fairly good
Medium-hard,
fibrous samples
Zirconium oxide
(96.2% ZrO
2
)
5.7
Very good
Fibrous, abrasive
samples
Stainless steel
Bowl:
(17-19% Cr + 8-10%
Ni)
Balls:
(12.5-14.5% Cr + 1%
Ni)
7.8
Fairly good
Medium-hard, brittle
samples
Hardened steel
Bowl: (11-12% Cr)
Balls: (1.0-1.65% Cr)
7.9
Good
Hard, brittle samples
Tungsten carbide
(93% WC+6% Co)
14.9
Very good
Hard, abrasive sam-
ples
The grinding bowls and grinding balls made of zirconium oxide are
resistant to acids - apart from hydrofluoric acid.
Normally choose a grinding bowl and grinding balls that are made of the
same material.
Exception: Tungsten carbide balls (<20 mm) may be temporarily (a few
minutes) combined with grinding bowls made of hardened steel.
Using the device
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