FRITSCH PULVERISETTE 23 - Manual (Page 20)

These are reference values: The size of bowls and grinding balls may
need to be determined through experimentation.
NOTICE!
It is not advisable to mix balls of different diameters. (If
balls with different diameters are used, increased wear to
the balls is to be expected.)
Fill the grinding bowl with as few balls as possible as the abrasion, wear
and stress on the device and the grinding bowl increases significantly
when filled with more balls. We recommend using a maximum of 3 balls
with a Ø of 10 mm for a 10 ml grinding bowl and a maximum of 6 balls
with a Ø of 10 mm for a 15 ml grinding bowl. No guarantee can be made
if this is exceeded. Balls smaller than Ø 5 mm can also be used to pro-
duce a finer end product. The filling quantity has to be determined
through experimentation.
6.1.2 Number of balls per grinding bowl (independent of the material quantity)
A higher number of balls will reduce the grinding duration and the
grinding results will be within a smaller grain size range.
Grinding bowl /
Useful capacity
(grinding stock)
15 ml / 0.5 - 5
ml
10 ml / 0.2 - 1
ml
5 ml / 0.01 - 1
ml
Balls ∅
15 mm 2 1
10 mm 5 3 1
5 mm 60 30 20
The number of balls should be complied with to avoid unnecessary wear.
The lowest number of balls is the minimum filling quantity; the largest
number of balls is the ideal ball filling for the shortest grinding time (e.g.
8 balls with a diameter of 10 mm is ideal for the 15 ml grinding bowl).
6.1.3 Calculated weight of a ball
Ball diameter in mm 5 10 15
Material Density in g/
cm 3
Calculated weight of a ball in g
Zirconium
oxide
5,9 0,37 2,98 10,07
Using the planetary mill
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