XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3841
influencing power dissipation and stress, key factors in mill
operation.
To extract the solids fraction profile from both PEPT
and DEM data, we follow these steps:
• Discretize the azimuthal plane of the drum into vox-
els (dimensions: d × d × λ), where d =10 mm, and λ
=200 mm is the drum length.
• Bin particle positions:
– In steady-state simulation, DEM data is binned
at N =1000 consecutive 10–3 s timesteps,
approximately one revolution of the drum. DEM
simulations are currently ongoing so the PEPT
data will be presented herein.
– PEPT positional data is binned over several hours,
creating a normalised residence time distribution
converted to solids fraction maps using total gran-
ular mass and voxel volume.
– Due to PEPT’s single tracer limitation, some phase
space regions may be uncovered. To address this, we
employ coarse graining with a Gaussian smoothing
kernel, acting as an energy barrier correction. This
procedure has a corresponding smoothing effect
on DEM data, eliminating pixilation introduced
by bin edges.
Solids Fraction
Figure 2 indicates that PEPT solids fractions range from 0
(blue dilated regions) to 0.7 (red densely packed regions).
Previous studies have indicated that the cataracting region
Table 1. Mill configuration
Dimensions
Internal Diameter (mm) 460
Internal Length (mm) 200
%Filling by Volume 50
Speeds Investigated (%Nc) 30, 45, 60
Viscosities investigated (Pa.s) 0.011, 0.03, 0.22
Figure 2. PEPT glass bead solids fraction results at various speeds and viscosities
influencing power dissipation and stress, key factors in mill
operation.
To extract the solids fraction profile from both PEPT
and DEM data, we follow these steps:
• Discretize the azimuthal plane of the drum into vox-
els (dimensions: d × d × λ), where d =10 mm, and λ
=200 mm is the drum length.
• Bin particle positions:
– In steady-state simulation, DEM data is binned
at N =1000 consecutive 10–3 s timesteps,
approximately one revolution of the drum. DEM
simulations are currently ongoing so the PEPT
data will be presented herein.
– PEPT positional data is binned over several hours,
creating a normalised residence time distribution
converted to solids fraction maps using total gran-
ular mass and voxel volume.
– Due to PEPT’s single tracer limitation, some phase
space regions may be uncovered. To address this, we
employ coarse graining with a Gaussian smoothing
kernel, acting as an energy barrier correction. This
procedure has a corresponding smoothing effect
on DEM data, eliminating pixilation introduced
by bin edges.
Solids Fraction
Figure 2 indicates that PEPT solids fractions range from 0
(blue dilated regions) to 0.7 (red densely packed regions).
Previous studies have indicated that the cataracting region
Table 1. Mill configuration
Dimensions
Internal Diameter (mm) 460
Internal Length (mm) 200
%Filling by Volume 50
Speeds Investigated (%Nc) 30, 45, 60
Viscosities investigated (Pa.s) 0.011, 0.03, 0.22
Figure 2. PEPT glass bead solids fraction results at various speeds and viscosities