3731
Full-Scale SAG Mill Modelling Using DEM-SPH Modelling
Nirmal Weerasekara, Jeremy Hanhiniemi
Weir Minerals Australia
Vinicius Daroz, Alexander Potapov, Rahul Bharadwaj
Ansys
ABSTRACT: With the development and improvements of state-of-the-art multi-GPU hardware capability and
high-fidelity Discrete Element Modelling (DEM) and Smoothed particle hydrodynamics (SPH) coupled solvers
like Ansys Rocky, the ability to capture very complex flow structures in grinding mills are ever closer to reality.
Traditionally, autogenous (AG) and semi-autogenous (SAG) grinding mills have been modelled using empirical
models or dry DEM models. In this work full scall SAG mill with rocks and slurry transport is modelled using
Rocky’s DEM-SPH coupled solver and compared against plant historic data. This work employs the newly
implemented Implicit incompressible SPH approach (IISPH) in Rocky. Furthermore this work paves the way
for design optimisations of the mill internals using this modelling method.
Keywords: SAG, Pulp-lifters, concentrator, SPH, DEM
INTRODUCTION
The aim of this work is to understand the slurry flow behav-
iour in the pulp discharge and its interface to the mill using
the coupled SPH-DEM technique compared with full
scale mills data (Weerasekara 2019 and 2022). This study
extends previous work and publications of the authors
(Weerasekara 2023 and 2023) that used ANSYS Rocky’s
new addition of SPH modelling capability to model the
experimental measurements from the author’s previous
publication (Weerasekara 2014), pilot scale experimental
tests (Mitchell 2015 and Vijayakumar 2015) and author’s
previous published (Weerasekara 2019 and 2022) full scale
data.
This work focuses on validating fully coupled SPH-
DEM results against full-scale data. Also in this work newly
implemented IISPH in Rocky is used compared to classic
weakly compressible SPH approach (WCSPH).
METHOD
SPH is a Lagrangian mesh-free method for continuum
media simulations (fluid flows and solid deformations). For
the simulations of the incompressible fluid flows, two SPH
approaches could be used.
Classic Weakly Compressible SPH Approach
(WCSPH)
The first one is the classic weakly compressible SPH
approach (WCSPH) (Monaghan 1994) with the Wendland
kernel function. In this approach, the fluid is simulated
explicitly as a compressible one with the stiff equation of
state (small density changes). The details of this approach
are described in Rocky (2023).
Full-Scale SAG Mill Modelling Using DEM-SPH Modelling
Nirmal Weerasekara, Jeremy Hanhiniemi
Weir Minerals Australia
Vinicius Daroz, Alexander Potapov, Rahul Bharadwaj
Ansys
ABSTRACT: With the development and improvements of state-of-the-art multi-GPU hardware capability and
high-fidelity Discrete Element Modelling (DEM) and Smoothed particle hydrodynamics (SPH) coupled solvers
like Ansys Rocky, the ability to capture very complex flow structures in grinding mills are ever closer to reality.
Traditionally, autogenous (AG) and semi-autogenous (SAG) grinding mills have been modelled using empirical
models or dry DEM models. In this work full scall SAG mill with rocks and slurry transport is modelled using
Rocky’s DEM-SPH coupled solver and compared against plant historic data. This work employs the newly
implemented Implicit incompressible SPH approach (IISPH) in Rocky. Furthermore this work paves the way
for design optimisations of the mill internals using this modelling method.
Keywords: SAG, Pulp-lifters, concentrator, SPH, DEM
INTRODUCTION
The aim of this work is to understand the slurry flow behav-
iour in the pulp discharge and its interface to the mill using
the coupled SPH-DEM technique compared with full
scale mills data (Weerasekara 2019 and 2022). This study
extends previous work and publications of the authors
(Weerasekara 2023 and 2023) that used ANSYS Rocky’s
new addition of SPH modelling capability to model the
experimental measurements from the author’s previous
publication (Weerasekara 2014), pilot scale experimental
tests (Mitchell 2015 and Vijayakumar 2015) and author’s
previous published (Weerasekara 2019 and 2022) full scale
data.
This work focuses on validating fully coupled SPH-
DEM results against full-scale data. Also in this work newly
implemented IISPH in Rocky is used compared to classic
weakly compressible SPH approach (WCSPH).
METHOD
SPH is a Lagrangian mesh-free method for continuum
media simulations (fluid flows and solid deformations). For
the simulations of the incompressible fluid flows, two SPH
approaches could be used.
Classic Weakly Compressible SPH Approach
(WCSPH)
The first one is the classic weakly compressible SPH
approach (WCSPH) (Monaghan 1994) with the Wendland
kernel function. In this approach, the fluid is simulated
explicitly as a compressible one with the stiff equation of
state (small density changes). The details of this approach
are described in Rocky (2023).