XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 103
alternative, as demonstrated by Jokovic et al. (2022) in a
pilot study, is hybrid cyclone-screen classification. It can
significantly reduce grinding energy and improve the liber-
ation of valuable minerals at a coarser grind size compared
to conventional hydrocyclone classification.
Adoption of new technologies for comminution and
classification, however, is challenging. Implementation into
brownfield circuits is usually difficult or not feasible and
adopting a new technology for comminution is high risk
because of the high capital costs involved.
IMPROVING FLOTATION
HYDRODYNAMICS
Coarse Particle Flotation
Conventional flotation tank hydrodynamics do not result
in effective coarse particle flotation. Fluidised bed flotation,
however, is an emerging new technology in base-metal
flotation proving capable of achieving recovery of coarse
particles up to 600 to 800 µm in size, even for particles that
are not well liberated (Kohmuench et al, 2018 Seaman and
Vollert, 2017). Fluidised bed flotation units have a much
less turbulent hydrodynamic environment than a conven-
tional cell, resulting in less detachment and higher prob-
abilities of coarse particle flotation.
The HydroFloat ®, commercialized by Eriez, is the mar-
ket leading fluidized bed technology, with many industrial
full-scale units installed across a variety of commodities,
including more recently in base metal sulfide flotation.
A diagram of the major components that comprise the
HydroFloat ® cell is shown in Figure 5. Figure 5 also shows
an example of the improvement in copper recovery of coarse
particles in the HydroFloat ® compared to that of a conven-
tional laboratory flotation cell. In the HydroFloat ®, feed
falls through a freeboard zone before settling into the fluid-
ized bed created using an upward flow of water. Without
the need for a rotor to keep particles in suspension, the
Figure 4. Improvement in liberation of the 53 µm size fraction of the flotation feed and the improvement in coarse particle
flotation recovery when screens were used instead of cyclones in a ball milling circuit (after Frausto et al, 2017)
Figure 5. Simplified diagram of the HydroFloat ® (Kohmuench et al, 2018) and a comparison between HydroFloat ® and
conventional flotation performance (Mehrfert, 2017)
alternative, as demonstrated by Jokovic et al. (2022) in a
pilot study, is hybrid cyclone-screen classification. It can
significantly reduce grinding energy and improve the liber-
ation of valuable minerals at a coarser grind size compared
to conventional hydrocyclone classification.
Adoption of new technologies for comminution and
classification, however, is challenging. Implementation into
brownfield circuits is usually difficult or not feasible and
adopting a new technology for comminution is high risk
because of the high capital costs involved.
IMPROVING FLOTATION
HYDRODYNAMICS
Coarse Particle Flotation
Conventional flotation tank hydrodynamics do not result
in effective coarse particle flotation. Fluidised bed flotation,
however, is an emerging new technology in base-metal
flotation proving capable of achieving recovery of coarse
particles up to 600 to 800 µm in size, even for particles that
are not well liberated (Kohmuench et al, 2018 Seaman and
Vollert, 2017). Fluidised bed flotation units have a much
less turbulent hydrodynamic environment than a conven-
tional cell, resulting in less detachment and higher prob-
abilities of coarse particle flotation.
The HydroFloat ®, commercialized by Eriez, is the mar-
ket leading fluidized bed technology, with many industrial
full-scale units installed across a variety of commodities,
including more recently in base metal sulfide flotation.
A diagram of the major components that comprise the
HydroFloat ® cell is shown in Figure 5. Figure 5 also shows
an example of the improvement in copper recovery of coarse
particles in the HydroFloat ® compared to that of a conven-
tional laboratory flotation cell. In the HydroFloat ®, feed
falls through a freeboard zone before settling into the fluid-
ized bed created using an upward flow of water. Without
the need for a rotor to keep particles in suspension, the
Figure 4. Improvement in liberation of the 53 µm size fraction of the flotation feed and the improvement in coarse particle
flotation recovery when screens were used instead of cyclones in a ball milling circuit (after Frausto et al, 2017)
Figure 5. Simplified diagram of the HydroFloat ® (Kohmuench et al, 2018) and a comparison between HydroFloat ® and
conventional flotation performance (Mehrfert, 2017)