Technical Implications of Organic Syntheses in Ball Mills - Ball Milling Towards Green Synthesis: Applications, Projects, Challenges - page 247

Figure 10.2 Working principle of different ball mills used for organic synthesis.
PBM: planetary ball mill; MBM: mixer ball mill; VBM: vibration ball
mill.

Figure 10.3 Set of milling technologies currently used at the laboratory and (pilot)

plant scale for the performance of mechano-chemical reactions and the
processing of biomass. (A) SPEX mixer mill (V MV,max ¼ 0.065 L). (B)
Planetary ball mill (V MV,max ¼ 0.5 L). (C) Attritor (V MV ¼ 4 L). (D) Rolling
ball mill (V MV,max ¼ up to m 3 -scale).
Reproduced from ref. 50 with permission of the Royal Society of
Chemistry.

milling beakers follow typical trajectories that recently have been monitored
by video analysis and simulated with the help of the discrete element
method (DEM; Figure 10.4). 53,54 Despite improvements it is still complicated
to calculate the specific trajectories of the milling balls inside the beakers
due to overlap of the two opposite rotation directions of the sun and the
planetary disks. 53,55 It is generally accepted that the milling balls are accel-
erated and follow the rotation of the milling beaker for approximately one
quarter of its perimeter, then they are moving through the volume of the
milling beaker and collide with the opposite wall. The point at which the
grinding bodies leave their centrifugal trajectory (release point; with respect