XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 105
and repulsive forces in accordance with DLVO theory
(Derjaguin and Landau, 1941 Verwey and Overbeek,
1948). Many of these interfacial forces can be manipulated
by carefully adjusting the chemical environment of the flo-
tation system. Metallurgists have many tools at their dis-
posal to achieve this: frothers, depressants, activators and
surface modifiers such as pH and Eh.
One of the key forces that determine the success of
bubble/particle attachment is hydrophobic attraction. In
flotation, this attraction is produced by reagents called col-
lectors. The role of a collector in flotation is twofold. Firstly,
a collector must be strong enough to impart hydrophobic-
ity (the ability to repel water) onto a mineral surface. But
more importantly, the collector needs to be selective in
order to limit its effect to specific target mineral phases. The
development of a truly selective flotation collector remains
a challenge.
In base metal sulphide flotation, thiol-based reagents
(e.g., xanthates, thiocarbamates, dithiophosphates, etc)
are highly effective in separating sulphide minerals from
non-sulphide gangue. However, their selectivity becomes
limited when it comes to distinguishing between differ-
ent sulphides with similar surface properties. Examples of
those include chalcopyrite/pyrite (Ackerman et al., 1987
Ekmekçi and Demirel, 1997) and pyrite/arsenopyrite sepa-
rations (Guang Ming et al., 1992).
The development of flotation chemistry targeted at
oxide flotation, has not received the same degree of atten-
tion as base metal sulphide flotation over the last few
decades. This was largely driven by the fact that oxide min-
erals tend to represent more bulk and low-cost commodi-
ties. However, the drive towards renewable energy means
that the increased production of critical metals such as rare
earth elements (REEs), lithium and vanadium has become
imperative. These critical metals are often hosted in oxide
mineral systems, where the challenge is the selective separa-
tion of similar oxide minerals from one another. The study
of flotation reagents and chemistry technologies for oxide
minerals is now becoming the new frontier in research and
development (Cook and Gibson, 2023 Filippov et al.,
2019 Moon and Fuerstenau, 2003).
Several advances in the field of reagent chemistry have
recently emerged. The use of bioreagents such as peptides
(or mini proteins) is one such exciting new development.
Peptides have long been used in biomedical applications
and are well known for their high specificity towards tar-
get elemental species. The development of peptide-based
flotation collectors has the potential to completely revo-
lutionize our approach to developing mineral-specific
reagents. This field is still in its infancy, with a large por-
tion of the work focusing on peptide adsorption onto pure
metal ions and surfaces. However, some research is being
performed on more complex mineral surfaces. One of the
Figure 6. Schematic diagrams of the Jameson Cell’s downcomer (Wills and Finch, 2016) and the Jameson Cell flotation system
(Young et al, 2006)
and repulsive forces in accordance with DLVO theory
(Derjaguin and Landau, 1941 Verwey and Overbeek,
1948). Many of these interfacial forces can be manipulated
by carefully adjusting the chemical environment of the flo-
tation system. Metallurgists have many tools at their dis-
posal to achieve this: frothers, depressants, activators and
surface modifiers such as pH and Eh.
One of the key forces that determine the success of
bubble/particle attachment is hydrophobic attraction. In
flotation, this attraction is produced by reagents called col-
lectors. The role of a collector in flotation is twofold. Firstly,
a collector must be strong enough to impart hydrophobic-
ity (the ability to repel water) onto a mineral surface. But
more importantly, the collector needs to be selective in
order to limit its effect to specific target mineral phases. The
development of a truly selective flotation collector remains
a challenge.
In base metal sulphide flotation, thiol-based reagents
(e.g., xanthates, thiocarbamates, dithiophosphates, etc)
are highly effective in separating sulphide minerals from
non-sulphide gangue. However, their selectivity becomes
limited when it comes to distinguishing between differ-
ent sulphides with similar surface properties. Examples of
those include chalcopyrite/pyrite (Ackerman et al., 1987
Ekmekçi and Demirel, 1997) and pyrite/arsenopyrite sepa-
rations (Guang Ming et al., 1992).
The development of flotation chemistry targeted at
oxide flotation, has not received the same degree of atten-
tion as base metal sulphide flotation over the last few
decades. This was largely driven by the fact that oxide min-
erals tend to represent more bulk and low-cost commodi-
ties. However, the drive towards renewable energy means
that the increased production of critical metals such as rare
earth elements (REEs), lithium and vanadium has become
imperative. These critical metals are often hosted in oxide
mineral systems, where the challenge is the selective separa-
tion of similar oxide minerals from one another. The study
of flotation reagents and chemistry technologies for oxide
minerals is now becoming the new frontier in research and
development (Cook and Gibson, 2023 Filippov et al.,
2019 Moon and Fuerstenau, 2003).
Several advances in the field of reagent chemistry have
recently emerged. The use of bioreagents such as peptides
(or mini proteins) is one such exciting new development.
Peptides have long been used in biomedical applications
and are well known for their high specificity towards tar-
get elemental species. The development of peptide-based
flotation collectors has the potential to completely revo-
lutionize our approach to developing mineral-specific
reagents. This field is still in its infancy, with a large por-
tion of the work focusing on peptide adsorption onto pure
metal ions and surfaces. However, some research is being
performed on more complex mineral surfaces. One of the
Figure 6. Schematic diagrams of the Jameson Cell’s downcomer (Wills and Finch, 2016) and the Jameson Cell flotation system
(Young et al, 2006)