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Predicting the Performance of an Industrial HPGR with Severely
Worn Rollers Using DEM
V. A. Rodriguez, G. K. P. Barrios, T. M. Campos, H. A. Petit, L. M. Tavares
Department of Metallurgical and Materials Engineering,
Universidade Federal do Rio de Janeiro—COPPE/UFRJ, Rio de Janeiro, Brazil
ABSTRACT: The application of dynamic modeling and simulation of high-pressure grinding rolls (HPGR)
has grown in the last few years in the minerals industry. In that regard, a pseudo-dynamic modeling approach
based on phenomenological modeling has been successfully applied to describe the continuous operation of
the HPGR for grinding iron ore concentrates. Those models can accurately describe the throughput, power,
and Blaine-specific surface area (BSA) of the product based on operating conditions such as working gap,
operating pressure, roll velocity, and feed BSA. However, the models present a deviation in predicting the
performance variables as rollers become progressively worn during months and years of operation. In general,
for this particular application, the rollers can operate up to 15,000 hours before being changed or repaired,
during which the wear profile directly influences the process control strategy to keep the machine capacity and
the product BSA constant. To better understand what happens inside the HPGR with the worn rollers, the
present work simulated an industrial-scale HPGR using the discrete element method (DEM) coupled with
multi-body dynamics and the particle replacement model. Simulation results such as throughput, power, and
working gap are compared with an industrial survey, demonstrating good agreement between the two. The
DEM simulation allows the analysis of the pressure and mass flow profiles along the roll length for both new
and worn rollers. DEM simulations were able to describe the reduction in power, throughput, and fineness of
the product size distribution, as well as the significant drop in pressure and an increase in mass flow in the center
of the rolls, which is the area that exhibits the most severe wear.
Keywords: High-pressure grinding roll, DEM, simulation, modelling
INTRODUCTION
Modelling and real-time prediction of the performance
variables of high-pressure grinding roll (HPGR) opera-
tion presents a challenge, mainly at the industrial scale.
Today, advanced modelling tools based on artificial intelli-
gence, data analysis, and phenomenological modelling can
simultaneously assess multivariable relationships between
HPGR operational variables and predicted product targets
(Chelgani et al., 2021 Tohry et al., 2021). The HPGR can
experience a great deal of roll wear, particularly when com-
minuting hard ores—due to abrasion and indentation –,
significantly affecting the HPGR’s performance and service
life (Lim et al., 1997). However, the several models have not
incorporated its influence mainly because it is not yet well
understood. For instance, Campos et al. (2023) proposed
a pseudo-dynamic model (PDM) and successfully applied
it to HPGRs pressing iron ore concentrate at a VALE pel-
letizing plant. The PDM described throughput, power, and
Predicting the Performance of an Industrial HPGR with Severely
Worn Rollers Using DEM
V. A. Rodriguez, G. K. P. Barrios, T. M. Campos, H. A. Petit, L. M. Tavares
Department of Metallurgical and Materials Engineering,
Universidade Federal do Rio de Janeiro—COPPE/UFRJ, Rio de Janeiro, Brazil
ABSTRACT: The application of dynamic modeling and simulation of high-pressure grinding rolls (HPGR)
has grown in the last few years in the minerals industry. In that regard, a pseudo-dynamic modeling approach
based on phenomenological modeling has been successfully applied to describe the continuous operation of
the HPGR for grinding iron ore concentrates. Those models can accurately describe the throughput, power,
and Blaine-specific surface area (BSA) of the product based on operating conditions such as working gap,
operating pressure, roll velocity, and feed BSA. However, the models present a deviation in predicting the
performance variables as rollers become progressively worn during months and years of operation. In general,
for this particular application, the rollers can operate up to 15,000 hours before being changed or repaired,
during which the wear profile directly influences the process control strategy to keep the machine capacity and
the product BSA constant. To better understand what happens inside the HPGR with the worn rollers, the
present work simulated an industrial-scale HPGR using the discrete element method (DEM) coupled with
multi-body dynamics and the particle replacement model. Simulation results such as throughput, power, and
working gap are compared with an industrial survey, demonstrating good agreement between the two. The
DEM simulation allows the analysis of the pressure and mass flow profiles along the roll length for both new
and worn rollers. DEM simulations were able to describe the reduction in power, throughput, and fineness of
the product size distribution, as well as the significant drop in pressure and an increase in mass flow in the center
of the rolls, which is the area that exhibits the most severe wear.
Keywords: High-pressure grinding roll, DEM, simulation, modelling
INTRODUCTION
Modelling and real-time prediction of the performance
variables of high-pressure grinding roll (HPGR) opera-
tion presents a challenge, mainly at the industrial scale.
Today, advanced modelling tools based on artificial intelli-
gence, data analysis, and phenomenological modelling can
simultaneously assess multivariable relationships between
HPGR operational variables and predicted product targets
(Chelgani et al., 2021 Tohry et al., 2021). The HPGR can
experience a great deal of roll wear, particularly when com-
minuting hard ores—due to abrasion and indentation –,
significantly affecting the HPGR’s performance and service
life (Lim et al., 1997). However, the several models have not
incorporated its influence mainly because it is not yet well
understood. For instance, Campos et al. (2023) proposed
a pseudo-dynamic model (PDM) and successfully applied
it to HPGRs pressing iron ore concentrate at a VALE pel-
letizing plant. The PDM described throughput, power, and