3838
Investigating Slurry Viscosity Effects in Tumbling Mills Using
Two-Way Coupled SPH-DEM Simulations
T.L. Moodley
Mintek, Randburg, Gauteng, South Africa
Discipline of Chemical Engineering, School of Engineering,
University of KwaZulu-Natal, Durban, South Africa
I. Govender
Mintek, Randburg, Gauteng, South Africa
Discipline of Chemical Engineering, School of Engineering,
University of KwaZulu-Natal, Durban, South Africa
Department of Chemical Engineering, Centre for Minerals Research,
University of Cape Town, Rondebosch, South Africa
ABSTRACT: This study introduces an innovative approach to investigating the influence of slurry viscosity
on tumbling mill performance. By coupling SPH with DEM simulations, the interplay between solid particles
and fluid in mills is comprehensively explored. The method is applied across a range of viscosity levels, revealing
insights into particle collisions and comminution efficiency. In the current study, a 460mm rotating drum filled
with 10mm glass beads at a 50% filling is utilised. To mimic a slurry, a water-glycerol mixture is introduced,
barely filling the voids between the beads. The findings offer valuable guidance for optimising mill design and
operational parameters.
Keywords: PEPT, DEM, SPH, tumbling mills
INTRODUCTION
The intricate interplay between grinding media and slurry
is pivotal for controlling key parameters, namely through-
put and grinding efficiency, in milling processes. Achieving
control necessitates measurement and subsequent optimiza-
tion of dynamic variables governing these factors. However,
reliable measurement of these variables is constrained to the
momentum transfer timescale (10–6s), posing challenges
for experimental verification.
To address this constraint, the Discrete Element
Method (DEM) serves as a numerical approach to obtain
crucial parameters, albeit with simplified assumptions.
Traditionally, coupling DEM with Computational Fluid
Dynamics (CFD) forms a DEM-CFD coupled simulation
to characterise slurry parameters.
Introducing Smoothed Particle Hydrodynamics (SPH)
offers a novel approach, overcoming limitations of tradi-
tional coupled simulations. SPH accommodates effects like
splashing, mitigating numerical convergence issues in CFD
simulations (Cleary and Sawley, 1999). This is crucial as
capturing microscopic point-wise effects, such as splash-
ing, requires an excessively fine simulation grid, leading
Investigating Slurry Viscosity Effects in Tumbling Mills Using
Two-Way Coupled SPH-DEM Simulations
T.L. Moodley
Mintek, Randburg, Gauteng, South Africa
Discipline of Chemical Engineering, School of Engineering,
University of KwaZulu-Natal, Durban, South Africa
I. Govender
Mintek, Randburg, Gauteng, South Africa
Discipline of Chemical Engineering, School of Engineering,
University of KwaZulu-Natal, Durban, South Africa
Department of Chemical Engineering, Centre for Minerals Research,
University of Cape Town, Rondebosch, South Africa
ABSTRACT: This study introduces an innovative approach to investigating the influence of slurry viscosity
on tumbling mill performance. By coupling SPH with DEM simulations, the interplay between solid particles
and fluid in mills is comprehensively explored. The method is applied across a range of viscosity levels, revealing
insights into particle collisions and comminution efficiency. In the current study, a 460mm rotating drum filled
with 10mm glass beads at a 50% filling is utilised. To mimic a slurry, a water-glycerol mixture is introduced,
barely filling the voids between the beads. The findings offer valuable guidance for optimising mill design and
operational parameters.
Keywords: PEPT, DEM, SPH, tumbling mills
INTRODUCTION
The intricate interplay between grinding media and slurry
is pivotal for controlling key parameters, namely through-
put and grinding efficiency, in milling processes. Achieving
control necessitates measurement and subsequent optimiza-
tion of dynamic variables governing these factors. However,
reliable measurement of these variables is constrained to the
momentum transfer timescale (10–6s), posing challenges
for experimental verification.
To address this constraint, the Discrete Element
Method (DEM) serves as a numerical approach to obtain
crucial parameters, albeit with simplified assumptions.
Traditionally, coupling DEM with Computational Fluid
Dynamics (CFD) forms a DEM-CFD coupled simulation
to characterise slurry parameters.
Introducing Smoothed Particle Hydrodynamics (SPH)
offers a novel approach, overcoming limitations of tradi-
tional coupled simulations. SPH accommodates effects like
splashing, mitigating numerical convergence issues in CFD
simulations (Cleary and Sawley, 1999). This is crucial as
capturing microscopic point-wise effects, such as splash-
ing, requires an excessively fine simulation grid, leading
