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Review of Surface Activation of Pyrite for Selective Separation of
Critical Elements
Mulenga Chibesa, Fardis Nakhaei
Department of Mining and Explosives Engineering, Missouri University of Science &Technology
Lana Alagha
Department of Mining and Explosives Engineering, Missouri University of Science &Technology
Thomas J. O’Keefe Institute for Sustainable Supply of Strategic Minerals, Missouri University of Science &Technology
ABSTRACT: In the porphyry copper sulfide flotation process, pyrite, an uneconomic sulfide mineral, is
usually depressed at early flotation stages and eventually ends up in mine tailings. Pyrite in the tailings poses an
environmental issue due to acid mine drainage. However, it also offers an opportunity, as pyrite is a good host
for “critical elements” such as Tellurium (Te), which is essential for a future decarbonized economy, as well as
precious metals like Gold (Au) and Silver (Ag). Other important elements hosted in pyrite include Bismuth
(Bi), Selenium (Se), Antimony (Sb), and Arsenic (As).
Pyrite in the mine tailings can be concentrated using froth flotation process to enrich critical minerals/ele-
ments, however, surface activation is needed to enhance the separation efficiency. This review investigates the
various surfactants for selective activation of pyrite surfaces to facilitate its flotation. Fundamental insights into
the adsorption mechanism and selectivity of potential surfactant systems on pyrite’s surfaces are also provided.
The review serves as a foundation for exploring novel flotation systems and activators, aiming to achieve cost-
effective and environmentally friendly pyrite separation for the enrichment of critical and precious minerals.
Keywords: pyrite, critical minerals, polymetallic sulfides, froth flotation, activators
INTRODUCTION
Porphyry copper deposits are typically low-grade ores
with an average copper grade between 0.4 and 1%. The
primary and main copper bearing mineral is chalcopyrite
(CuFeS2), which is mostly finely disseminated within the
host porphyritic rocks. Pyrite (FeS2) is the most com-
mon non-economic sulfide gangue mineral, that is usually
found associated with chalcopyrite and other second-
ary copper sulfide minerals (chalcocite (Cu2S), covellite
(CuS) etc). Pyrite must be eliminated at the early stages
of mineral processing to enhance the concentrate quality
for further processing (Nakhaei et al., 2016). Sulfur con-
tamination derived from pyrite in the concentrate has been
an obstacle in smelting and converting processes primar-
ily due to its potential to induce severe corrosion in heat
exchange and dust collection equipment, along with an
elevation in the volume of acidic wastewater (Zhang et al.,
2021). The combustion of pyrite results in the generation
of sulfur dioxide gas (SO2), contributing to atmospheric
pollution. Furthermore, the inherent refractory nature of
pyrite amplifies the complexities in the smelting process,
leading to augmented expenditures in both the smelting
Review of Surface Activation of Pyrite for Selective Separation of
Critical Elements
Mulenga Chibesa, Fardis Nakhaei
Department of Mining and Explosives Engineering, Missouri University of Science &Technology
Lana Alagha
Department of Mining and Explosives Engineering, Missouri University of Science &Technology
Thomas J. O’Keefe Institute for Sustainable Supply of Strategic Minerals, Missouri University of Science &Technology
ABSTRACT: In the porphyry copper sulfide flotation process, pyrite, an uneconomic sulfide mineral, is
usually depressed at early flotation stages and eventually ends up in mine tailings. Pyrite in the tailings poses an
environmental issue due to acid mine drainage. However, it also offers an opportunity, as pyrite is a good host
for “critical elements” such as Tellurium (Te), which is essential for a future decarbonized economy, as well as
precious metals like Gold (Au) and Silver (Ag). Other important elements hosted in pyrite include Bismuth
(Bi), Selenium (Se), Antimony (Sb), and Arsenic (As).
Pyrite in the mine tailings can be concentrated using froth flotation process to enrich critical minerals/ele-
ments, however, surface activation is needed to enhance the separation efficiency. This review investigates the
various surfactants for selective activation of pyrite surfaces to facilitate its flotation. Fundamental insights into
the adsorption mechanism and selectivity of potential surfactant systems on pyrite’s surfaces are also provided.
The review serves as a foundation for exploring novel flotation systems and activators, aiming to achieve cost-
effective and environmentally friendly pyrite separation for the enrichment of critical and precious minerals.
Keywords: pyrite, critical minerals, polymetallic sulfides, froth flotation, activators
INTRODUCTION
Porphyry copper deposits are typically low-grade ores
with an average copper grade between 0.4 and 1%. The
primary and main copper bearing mineral is chalcopyrite
(CuFeS2), which is mostly finely disseminated within the
host porphyritic rocks. Pyrite (FeS2) is the most com-
mon non-economic sulfide gangue mineral, that is usually
found associated with chalcopyrite and other second-
ary copper sulfide minerals (chalcocite (Cu2S), covellite
(CuS) etc). Pyrite must be eliminated at the early stages
of mineral processing to enhance the concentrate quality
for further processing (Nakhaei et al., 2016). Sulfur con-
tamination derived from pyrite in the concentrate has been
an obstacle in smelting and converting processes primar-
ily due to its potential to induce severe corrosion in heat
exchange and dust collection equipment, along with an
elevation in the volume of acidic wastewater (Zhang et al.,
2021). The combustion of pyrite results in the generation
of sulfur dioxide gas (SO2), contributing to atmospheric
pollution. Furthermore, the inherent refractory nature of
pyrite amplifies the complexities in the smelting process,
leading to augmented expenditures in both the smelting
