User Manual

honor the warranty or accept complaints for instrument damage or personal injuries
occurring when disregarding the above information.
4.1 Choice of Grinding Jars and Grinding Balls
Caution!!!
No warranty or claims shall be accepted in case of damages caused on account of using
grinding jars and grinding balls that are not original accessories of the appliance.
In order to prevent excessive abrasion, the hardness of the grinding jar used and of the
grinding balls must be higher than that of the material used.
Material
density*
resistance to abrasion
(jar and balls)
in g/cm
3
Agate
(99.9% SiO
2
)
2.65
Good
Sintered corundum
(99.7% Al
2
O
3
)
3.8
Fairly good
Zirconium dioxide
(95% ZrO
2
)
6.06
Very good
Stainless steel
Jars: (17-19% Cr +
8-10% Ni)
Balls: (12,5-14,5%
Cr + 1% Ni)
7.93
Fairly good
Tungsten carbide
(93%WC+6% Co)
14.95
Very good
The grinding jars and grinding balls of zirconium dioxide are resistant to acids with the
exception of hydrofluoric acid.
Normally, grinding jars and grinding balls of the same material should be chosen.
Exception: Tungsten carbide balls (<20mm) may be combined (just a few minutes) with
steel jars. The size of the grinding jars and grinding balls should be determined
experimentally.
4.1.1 Size of the Grinding Balls
Type of feed material
Ball diameter
Hard samples feed particle size <10 mm
30 mm or 40 mm
Medium piece size (<5 mm)
20 mm
Fine material (0.5 mm)
10 mm or 5 mm
Homogenization of dry or liquid samples
10 mm
Homogenization of viscous samples
20 mm
These are just clues: the size of the grinding jars and grinding balls should be determined
experimentally if necessary.