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Testing the Scalability of a Small-Scale Fluidised Bed Flotation
Device for Coarse Particle Flotation
Bellson Awatey, Isabella Verster, Liza Forbes, Kym Runge
Julius Kruttschnitt Mineral Research Centre (JKMRC), Sustainable Minerals Institute,
The University of Queensland, Brisbane, QLD, Australia
ARC Centre of Excellence on Eco-Efficient Beneficiation of Minerals (CE200100009),
University of Newcastle, Callaghan, NSW, Australia
ABSTRACT: The Eriez HydroFloat ®, a fluidised bed flotation cell, has demonstrated the ability to recover
coarse sulphide particles up to 600 µm in size during flotation. However, the smallest available HydroFloat ® unit
requires approximately 15–25 kg of sample for a single batch test and several 100 kg of sample for a complete
suite test program when it is operated in a continuous mode. This high sample requirement often limits the
execution of small-scale testing such as ore amenability flotation tests and geometallurgical assessments.
This has necessitated the need to develop a small-scale fluidised bed flotation device that enables rapid and effi-
cient testing for important parameters such as ore amenability, geometallurgical evaluation, circuit modelling,
design, and more routine metallurgical assessment.
This work presents the outcomes of flotation tests conducted in a small-scale fluidised bed flotation device that
uses 1–2 kg of copper ore sample and compares the results to those obtained from tests conducted in a full-scale
industrial HydroFloat ® unit, operating at a throughput of 300 tph.
Keywords: Coarse particle flotation, Fluidised bed flotation, HydroFloat ®
INTRODUCTION
The desire to increase the upper limits of coarse particle
flotation of base metals has been a long-standing challenge
for the mineral processing industry. This desire is borne out
of the need to reduce energy consumption significantly in
the comminution stage before flotation. Almost 40% of
all the energy consumed in most mining operations goes
towards comminution (Ballantyne et al., 2012). This is
because conventional flotation, the predominant method
for recovering valuable minerals, is only effective when
treating a narrow size range (20–150 µm) (Jameson, 2010).
Conventional flotation cells are ineffective for floating
particles above 150 µm, where a recovery drop is usually
observed (Lynch et al., 1981, Trahar, 1981, Kohmuench et
al., 2018). The poor flotation recovery of coarse particles
in conventional flotation cells is often attributed to the
high turbulent energy dissipation by the rotating impeller.
Increasing the impeller speed increases the local turbulent
energy dissipation rate, which increases particle-bubble
detachment (Grano, 2006, Shi and Fornasiero, 2009).
The HydroFloat ®, a fluidised bed technology, was
developed to address the challenges of the conventional
flotation cell. It was originally developed for the flotation
of coarse, low-density and liberated non-sulphide minerals
such as phosphate, potash, feldspar, vermiculite, and coal
Testing the Scalability of a Small-Scale Fluidised Bed Flotation
Device for Coarse Particle Flotation
Bellson Awatey, Isabella Verster, Liza Forbes, Kym Runge
Julius Kruttschnitt Mineral Research Centre (JKMRC), Sustainable Minerals Institute,
The University of Queensland, Brisbane, QLD, Australia
ARC Centre of Excellence on Eco-Efficient Beneficiation of Minerals (CE200100009),
University of Newcastle, Callaghan, NSW, Australia
ABSTRACT: The Eriez HydroFloat ®, a fluidised bed flotation cell, has demonstrated the ability to recover
coarse sulphide particles up to 600 µm in size during flotation. However, the smallest available HydroFloat ® unit
requires approximately 15–25 kg of sample for a single batch test and several 100 kg of sample for a complete
suite test program when it is operated in a continuous mode. This high sample requirement often limits the
execution of small-scale testing such as ore amenability flotation tests and geometallurgical assessments.
This has necessitated the need to develop a small-scale fluidised bed flotation device that enables rapid and effi-
cient testing for important parameters such as ore amenability, geometallurgical evaluation, circuit modelling,
design, and more routine metallurgical assessment.
This work presents the outcomes of flotation tests conducted in a small-scale fluidised bed flotation device that
uses 1–2 kg of copper ore sample and compares the results to those obtained from tests conducted in a full-scale
industrial HydroFloat ® unit, operating at a throughput of 300 tph.
Keywords: Coarse particle flotation, Fluidised bed flotation, HydroFloat ®
INTRODUCTION
The desire to increase the upper limits of coarse particle
flotation of base metals has been a long-standing challenge
for the mineral processing industry. This desire is borne out
of the need to reduce energy consumption significantly in
the comminution stage before flotation. Almost 40% of
all the energy consumed in most mining operations goes
towards comminution (Ballantyne et al., 2012). This is
because conventional flotation, the predominant method
for recovering valuable minerals, is only effective when
treating a narrow size range (20–150 µm) (Jameson, 2010).
Conventional flotation cells are ineffective for floating
particles above 150 µm, where a recovery drop is usually
observed (Lynch et al., 1981, Trahar, 1981, Kohmuench et
al., 2018). The poor flotation recovery of coarse particles
in conventional flotation cells is often attributed to the
high turbulent energy dissipation by the rotating impeller.
Increasing the impeller speed increases the local turbulent
energy dissipation rate, which increases particle-bubble
detachment (Grano, 2006, Shi and Fornasiero, 2009).
The HydroFloat ®, a fluidised bed technology, was
developed to address the challenges of the conventional
flotation cell. It was originally developed for the flotation
of coarse, low-density and liberated non-sulphide minerals
such as phosphate, potash, feldspar, vermiculite, and coal