3148 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
and associated sulphide minerals. Mu et al. (2018) reported
that the galvanic interaction between chalcopyrite and
pyrite resulted in reduced floatability of chalcopyrite. The
deleterious influence of galvanic interactions are further
illustrated by both Yang et al. (2021) and Qin et al. (2015),
who reported changes in chalcopyrite and galena flotation
behavior as a function of interaction with both monoclinic
pyrrhotite and pyrite, respectively.
Furthermore, galvanic interactions inadvertently alter
pulp chemistry as the surface species of sulphide minerals
change with varying pulp chemistry variables (Mu et al.,
2018). Several studies have shown that galvanic interac-
tions during sulphide mineral flotation tend to change pulp
potential and, consequently, flotation response due to the
controlling nature of pulp potential on redox reactions dur-
ing flotation (Mu et al., 2018 Goktep et at., 2002 Feng et
al., 1999). Furthermore, Goktep et al. (2002) reported that
pulp chemistry variables such as pH and Eh dictate the type
of collector species present in pulp and, consequently, flota-
tion performance. These factors present one of the many
layers of complexity in the selective separation of chalco-
pyrite from associated gangue minerals such as pyrrhotite.
The influence of pulp chemistry and galvanic interac-
tions on the flotation behavior of chalcopyrite has been
extensively explored in the literature however, the coupled
influence of these factors has not been studied. This study
contributes to the well-established discourse on chalcopyrite
flotation by investigating the implications of the influence
of pulp chemistry parameters (pH and ORP) and galvanic
interactions with pyrrhotite superstructures (hexagonal and
monoclinic). The interplay between pulp chemistry and
galvanic interactions holds not only theoretical significance
but also offers practical applicability for achieving precise
control over the flotation of chalcopyrite. The objective
of this study is to fill the current gap in the literature by
conducting a thorough examination of how pH, ORP, and
galvanic interaction collectively impact chalcopyrite flota-
tion. This will enhance our understanding of the complex
interactions that control this process. Specifically, the study
examines the impact of these variables on the electrochemi-
cal reactions and the subsequent flotation response of chal-
copyrite. Furthermore, the study seeks to reveal the precise
mechanisms by which these parameters collectively influ-
ence flotation efficiency, thereby addressing a crucial gap
in our existing understanding and facilitating the develop-
ment of optimal flotation systems.
METHODS
Samples and Chemicals
The chalcopyrite sample used in this study was purchased
from Ward’s Natural Science and sourced from mines in
the Durango state of Mexico. Similarly, the hexagonal pyr-
rhotite was acquired from Ward’s Natural Science, with
its source attributed to the Galax Mine in Virginia, USA.
Monoclinic pyrrhotite, was extracted from Vale’s Clarabelle
Mill feed using a hand magnet. To achieve a homogeneous
and consistent size fraction, all samples were dry pulverized
utilizing stainless steel pots with a target size fraction of
–120 µm/+75 µm. Potassium sulfide, acquired with a purity
of 99.99%, was sourced from Thermo Fisher Scientific.
Methyl Isobutyl Carbinol (MIBC), used as a frother dur-
ing microflotation tests, was procured from Sigma Aldrich.
Sodium isopropyl xanthate (SIPX), utilized as the primary
collector, was obtained from Thermo Fisher Scientific. The
use of the selected samples and chemicals ensures the preci-
sion and reproducibility of the experimental results.
Chemical and Mineralogical Analysis
The mineralogical phases and chemical compositions of
the samples were confirmed through a combination of
X-ray diffraction (XRD) and scanning electron micros-
copy (SEM) at the Department of Geological Sciences
at Queen’s University. Mineralogical purity was further
confirmed using X-ray powder diffraction (XRD) on a
Bruker D8 Powder Diffractometer machine. The samples
were ground to a top size of –38 µm, and mineral phase
purity was assessed using 2θ data collection at a step size
of 0.0340. XRD data collection operated at an accelerating
voltage of 40 kV and a current of 25 mA for CuKα radia-
tion. Reduction and phase identification were performed
using PANalytical X’pert HighScore Plus software. SEM
data were collected in both back-scatter mode and using
the energy dispersive spectroscopy (EDS) sensor, with oper-
ating conditions set at an accelerating voltage of 25 kV and
a current ranging between 9 nA to 10 nA.
Microflotation
Microflotation tests were used to understand the influ-
ence of pyrhottite superstructure content on the flotation
response of chalcopyrite under different pulp chemistry
conditions. The flotation tests were performed in a 60 ml
plexiglass flotation cell with magnetic stirrer as the impel-
ler at 1500 rpm. The tests were performed using 2 g of
chalcopyrite with varying proportions (0–40%) and ratios
(1:1, 2:1 and 3:1) of pyrrhotite superstructures (mono-
clinic and hexagonal). The de-ionized water used in this
experiment was prepared using potassium sulfite to obtain
and associated sulphide minerals. Mu et al. (2018) reported
that the galvanic interaction between chalcopyrite and
pyrite resulted in reduced floatability of chalcopyrite. The
deleterious influence of galvanic interactions are further
illustrated by both Yang et al. (2021) and Qin et al. (2015),
who reported changes in chalcopyrite and galena flotation
behavior as a function of interaction with both monoclinic
pyrrhotite and pyrite, respectively.
Furthermore, galvanic interactions inadvertently alter
pulp chemistry as the surface species of sulphide minerals
change with varying pulp chemistry variables (Mu et al.,
2018). Several studies have shown that galvanic interac-
tions during sulphide mineral flotation tend to change pulp
potential and, consequently, flotation response due to the
controlling nature of pulp potential on redox reactions dur-
ing flotation (Mu et al., 2018 Goktep et at., 2002 Feng et
al., 1999). Furthermore, Goktep et al. (2002) reported that
pulp chemistry variables such as pH and Eh dictate the type
of collector species present in pulp and, consequently, flota-
tion performance. These factors present one of the many
layers of complexity in the selective separation of chalco-
pyrite from associated gangue minerals such as pyrrhotite.
The influence of pulp chemistry and galvanic interac-
tions on the flotation behavior of chalcopyrite has been
extensively explored in the literature however, the coupled
influence of these factors has not been studied. This study
contributes to the well-established discourse on chalcopyrite
flotation by investigating the implications of the influence
of pulp chemistry parameters (pH and ORP) and galvanic
interactions with pyrrhotite superstructures (hexagonal and
monoclinic). The interplay between pulp chemistry and
galvanic interactions holds not only theoretical significance
but also offers practical applicability for achieving precise
control over the flotation of chalcopyrite. The objective
of this study is to fill the current gap in the literature by
conducting a thorough examination of how pH, ORP, and
galvanic interaction collectively impact chalcopyrite flota-
tion. This will enhance our understanding of the complex
interactions that control this process. Specifically, the study
examines the impact of these variables on the electrochemi-
cal reactions and the subsequent flotation response of chal-
copyrite. Furthermore, the study seeks to reveal the precise
mechanisms by which these parameters collectively influ-
ence flotation efficiency, thereby addressing a crucial gap
in our existing understanding and facilitating the develop-
ment of optimal flotation systems.
METHODS
Samples and Chemicals
The chalcopyrite sample used in this study was purchased
from Ward’s Natural Science and sourced from mines in
the Durango state of Mexico. Similarly, the hexagonal pyr-
rhotite was acquired from Ward’s Natural Science, with
its source attributed to the Galax Mine in Virginia, USA.
Monoclinic pyrrhotite, was extracted from Vale’s Clarabelle
Mill feed using a hand magnet. To achieve a homogeneous
and consistent size fraction, all samples were dry pulverized
utilizing stainless steel pots with a target size fraction of
–120 µm/+75 µm. Potassium sulfide, acquired with a purity
of 99.99%, was sourced from Thermo Fisher Scientific.
Methyl Isobutyl Carbinol (MIBC), used as a frother dur-
ing microflotation tests, was procured from Sigma Aldrich.
Sodium isopropyl xanthate (SIPX), utilized as the primary
collector, was obtained from Thermo Fisher Scientific. The
use of the selected samples and chemicals ensures the preci-
sion and reproducibility of the experimental results.
Chemical and Mineralogical Analysis
The mineralogical phases and chemical compositions of
the samples were confirmed through a combination of
X-ray diffraction (XRD) and scanning electron micros-
copy (SEM) at the Department of Geological Sciences
at Queen’s University. Mineralogical purity was further
confirmed using X-ray powder diffraction (XRD) on a
Bruker D8 Powder Diffractometer machine. The samples
were ground to a top size of –38 µm, and mineral phase
purity was assessed using 2θ data collection at a step size
of 0.0340. XRD data collection operated at an accelerating
voltage of 40 kV and a current of 25 mA for CuKα radia-
tion. Reduction and phase identification were performed
using PANalytical X’pert HighScore Plus software. SEM
data were collected in both back-scatter mode and using
the energy dispersive spectroscopy (EDS) sensor, with oper-
ating conditions set at an accelerating voltage of 25 kV and
a current ranging between 9 nA to 10 nA.
Microflotation
Microflotation tests were used to understand the influ-
ence of pyrhottite superstructure content on the flotation
response of chalcopyrite under different pulp chemistry
conditions. The flotation tests were performed in a 60 ml
plexiglass flotation cell with magnetic stirrer as the impel-
ler at 1500 rpm. The tests were performed using 2 g of
chalcopyrite with varying proportions (0–40%) and ratios
(1:1, 2:1 and 3:1) of pyrrhotite superstructures (mono-
clinic and hexagonal). The de-ionized water used in this
experiment was prepared using potassium sulfite to obtain