1992 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
terminal velocity, requiring a greater fluidisation velocity
(Tripathy et al., 2017). Conversely, smaller particles can
be easily fluidised and suspended by the incoming fluid
flow due to their low settling velocity (Islam &Nguyen,
2021). Additionally, high fluid flowrates often coincide
with increased bed expansion. However, in the experi-
ments, the bed is comprised of particles of multiple sizes
ranging from 250 to 710 µm, each with different settling
velocities. Therefore, the fluidisation velocity will depend
on the quantity of particles of different sizes present in the
bed and their proximity to the upper or lower limit of the
size distribution.
Effect of Particle Size on Solid Distribution in a
Continuous Flow Environment
Figure 6 displays the numerically predicted solid distri-
bution profiles for different particle sizes under the same
operating conditions in a continuous flow setting. The
snapshots depict behaviour of particles with varying diam-
eters over time, as per the conditions outlined in Table 1.
Figure 6a illustrates particle behaviour after 60 seconds,
while Figure 6b shows the same after 120 seconds, with a
focus on spatial distribution along the domain height. The
figures reveal that particles ranging from 30 µm to 90 µm
are elutriated and transported toward the overflow follow-
ing the fluid flow path. In contrast, coarser particles tend to
settle towards the underflow under gravitational influence.
Since the model does not account for the underflow effect,
these coarser particles accumulate at the lower part of the
tank.
An intriguing observation arises for particle groups of
75 µm and 90 µm. While the majority of solids from the
75 µm group report to the overflow, a small percentage also
travels to the underflow. Similarly, for the 90 µm group,
although most solids go to the overflow, a higher percent-
age ends up in the underflow. This particle behaviour plays
a role in defining D50. In the case of particles with a diame-
ter of 150 µm, a significant portion of solids initially moves
upwards upon entering the domain however, after some
time, they return to the underflow.
In the CFD simulations, the partition curve is gen-
erated by measuring the mass flowrate for both overflow
Figure 5. Numerically predicted time-averaged (a) bed height, (b) differential pressure (c) change of fluidisation rate over the
period of 30 sec
terminal velocity, requiring a greater fluidisation velocity
(Tripathy et al., 2017). Conversely, smaller particles can
be easily fluidised and suspended by the incoming fluid
flow due to their low settling velocity (Islam &Nguyen,
2021). Additionally, high fluid flowrates often coincide
with increased bed expansion. However, in the experi-
ments, the bed is comprised of particles of multiple sizes
ranging from 250 to 710 µm, each with different settling
velocities. Therefore, the fluidisation velocity will depend
on the quantity of particles of different sizes present in the
bed and their proximity to the upper or lower limit of the
size distribution.
Effect of Particle Size on Solid Distribution in a
Continuous Flow Environment
Figure 6 displays the numerically predicted solid distri-
bution profiles for different particle sizes under the same
operating conditions in a continuous flow setting. The
snapshots depict behaviour of particles with varying diam-
eters over time, as per the conditions outlined in Table 1.
Figure 6a illustrates particle behaviour after 60 seconds,
while Figure 6b shows the same after 120 seconds, with a
focus on spatial distribution along the domain height. The
figures reveal that particles ranging from 30 µm to 90 µm
are elutriated and transported toward the overflow follow-
ing the fluid flow path. In contrast, coarser particles tend to
settle towards the underflow under gravitational influence.
Since the model does not account for the underflow effect,
these coarser particles accumulate at the lower part of the
tank.
An intriguing observation arises for particle groups of
75 µm and 90 µm. While the majority of solids from the
75 µm group report to the overflow, a small percentage also
travels to the underflow. Similarly, for the 90 µm group,
although most solids go to the overflow, a higher percent-
age ends up in the underflow. This particle behaviour plays
a role in defining D50. In the case of particles with a diame-
ter of 150 µm, a significant portion of solids initially moves
upwards upon entering the domain however, after some
time, they return to the underflow.
In the CFD simulations, the partition curve is gen-
erated by measuring the mass flowrate for both overflow
Figure 5. Numerically predicted time-averaged (a) bed height, (b) differential pressure (c) change of fluidisation rate over the
period of 30 sec