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The Behavior of Bubble Clusters at the Pulp-Froth Interface
Sayed Janishar Anzoom, Ghislain Bournival, Seher Ata
School of Minerals and Energy Resources Engineering, UNSW, Sydney, Australia
ABSTRACT: In fluidized bed flotation cells, a significant proportion of particles ascend in the form of bubble
clusters. However, specific clusters encounter hindrances at the pulp-froth interface, impeding their movement
into the froth phase. To comprehend this issue, experimental studies were conducted to observe the interactions
of these clusters with the froth phase and analyze their impact on coarse particle recovery. The results reveal that
clusters developed the froth phase, and a section adjoined the pulp phase. Coarse particles considered in this
study were successfully recovered through the froth.
INTRODUCTION
Froth flotation is a beneficiation process that is widely used
in the mineral processing industry for separating valuable
mineral particles from gangue particles. The process takes
place in a flotation cell, and there are two main phases: the
pulp phase and the froth phase. In the pulp phase, bubbles
and particles interact, and the hydrophobic particles selec-
tively attach to the bubbles. These bubble-particle aggre-
gates then rise to the top of the pulp phase. This phase is
often referred to as the collection phase, where the goal is to
selectively collect the valuable mineral particles. Following
the pulp phase, the froth phase is formed as a result of the
accumulation of bubble-particle aggregates at the top of the
pulp phase. The froth, essentially a collection of bubbles car-
rying hydrophobic particles, is then overflowed or skimmed
off from the top of the flotation cell. The purpose of the
froth phase is to control the concentrate grade by draining
out the gangue particles/non-selected particles, which are
primarily carried into the froth phase by entrained water
(Farrokhpay, 2011 Ata, 2012).
In recent years, there has been a great interest in coarse
particle flotation in the mining industry. This approach
involves floating particles at a coarser size range, providing
various advantages such as reduced energy consumption in
grinding processes, lower operational costs, reduced car-
bon emissions, and improved water recovery, and tailings
management (Jameson, 2012 Kohmuench et al., 2018).
The conventional flotation cells, however, face limitations
in efficiently recovering particles larger than 100 µm. This
challenge is primarily attributed to the high turbulence
prevailing in mechanical flotation cells. The introduction
of fluidized-bed flotation cells has addressed this limitation
by providing less turbulent conditions compared to con-
ventional flotation cells. The reduced turbulence in fluid-
ized-bed cells minimizes the detachment of coarse particles
from the bubbles, consequently increasing the floatability
of larger particles.
Due to the lower turbulence in the fluidized bed flota-
tion cell, significant bubble clusters are formed (Kohmuench
et al., 2018 Jameson et al., 2020). A bubble cluster refers
to an aggregate of bubbles and particles. These clusters
play a crucial role in levitating coarse particles within the
pulp phase, as the presence of multiple bubbles enhances
the positive buoyancy of the cluster (Jameson et al., 2020).
Moreover, coarse particles can attach to several other bub-
bles in the cluster, reducing the chances of detachment.
While bubble clusters prove beneficial in floating coarse
The Behavior of Bubble Clusters at the Pulp-Froth Interface
Sayed Janishar Anzoom, Ghislain Bournival, Seher Ata
School of Minerals and Energy Resources Engineering, UNSW, Sydney, Australia
ABSTRACT: In fluidized bed flotation cells, a significant proportion of particles ascend in the form of bubble
clusters. However, specific clusters encounter hindrances at the pulp-froth interface, impeding their movement
into the froth phase. To comprehend this issue, experimental studies were conducted to observe the interactions
of these clusters with the froth phase and analyze their impact on coarse particle recovery. The results reveal that
clusters developed the froth phase, and a section adjoined the pulp phase. Coarse particles considered in this
study were successfully recovered through the froth.
INTRODUCTION
Froth flotation is a beneficiation process that is widely used
in the mineral processing industry for separating valuable
mineral particles from gangue particles. The process takes
place in a flotation cell, and there are two main phases: the
pulp phase and the froth phase. In the pulp phase, bubbles
and particles interact, and the hydrophobic particles selec-
tively attach to the bubbles. These bubble-particle aggre-
gates then rise to the top of the pulp phase. This phase is
often referred to as the collection phase, where the goal is to
selectively collect the valuable mineral particles. Following
the pulp phase, the froth phase is formed as a result of the
accumulation of bubble-particle aggregates at the top of the
pulp phase. The froth, essentially a collection of bubbles car-
rying hydrophobic particles, is then overflowed or skimmed
off from the top of the flotation cell. The purpose of the
froth phase is to control the concentrate grade by draining
out the gangue particles/non-selected particles, which are
primarily carried into the froth phase by entrained water
(Farrokhpay, 2011 Ata, 2012).
In recent years, there has been a great interest in coarse
particle flotation in the mining industry. This approach
involves floating particles at a coarser size range, providing
various advantages such as reduced energy consumption in
grinding processes, lower operational costs, reduced car-
bon emissions, and improved water recovery, and tailings
management (Jameson, 2012 Kohmuench et al., 2018).
The conventional flotation cells, however, face limitations
in efficiently recovering particles larger than 100 µm. This
challenge is primarily attributed to the high turbulence
prevailing in mechanical flotation cells. The introduction
of fluidized-bed flotation cells has addressed this limitation
by providing less turbulent conditions compared to con-
ventional flotation cells. The reduced turbulence in fluid-
ized-bed cells minimizes the detachment of coarse particles
from the bubbles, consequently increasing the floatability
of larger particles.
Due to the lower turbulence in the fluidized bed flota-
tion cell, significant bubble clusters are formed (Kohmuench
et al., 2018 Jameson et al., 2020). A bubble cluster refers
to an aggregate of bubbles and particles. These clusters
play a crucial role in levitating coarse particles within the
pulp phase, as the presence of multiple bubbles enhances
the positive buoyancy of the cluster (Jameson et al., 2020).
Moreover, coarse particles can attach to several other bub-
bles in the cluster, reducing the chances of detachment.
While bubble clusters prove beneficial in floating coarse