XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2981
(Finch and Dobby, 2001). Similar outcomes were obtained
in this study a relatively higher bias was necessary to obtain
a satisfactory grade in concentrate. The bias range of 0.2 to
0.4 was identified as the ideal range for RFC with the mate-
rial used in this study. It’s important to remember that the
optimum bias rate is highly dependent on the type of mate-
rial, circuit type, and targeted residence time. In this study,
the flotation time was 15 minutes, which was longer than
typical for lab-scale copper sulfide flotation. It should be
noted again that, due to recirculation, the flotation experi-
ments were quite different from those conducted in a lab-
scale mechanical flotation cell. Consequently, the preferred
bias should be different based on the flotation time. A simi-
lar conclusion can be drawn when variables such as particle
size distribution and circuit type are changed.
CONCLUSIONS
In this research, an optimization study for the operating
parameters of the RFC (i.e., feed, gas, and wash water,
and bias fluxes) in copper flotation utilizing ore from the
KGHM Polkowice Copper Concentrator was successfully
conducted using the Box–Behnken design (BBD) within
the Design of Experiments (DOE) framework. The model
outputs provided by the DOE corroborated findings from
the literature and insights from experimental works at the
NTNU Mineral Processing Lab. The key findings are sum-
marized as follows
• The gas flux is the most influential operating param-
eter for both grade and recovery as it directly deter-
mines the amount of overflow. However, the impact
of gas flux on the recovery is more pronounced than
its effect on the grade. For the Cu grade, the influ-
ence of other parameters becomes significant as well,
reducing the relative contribution of gas flux, even
though it remains the most dominant factor.
• For both grade and recovery, bias was observed as the
second most influential parameter and optimizing
the concentrate grade is a more complex task than
optimizing recovery.
• Even though the feed flux is known to affect the
hydrodynamic of the cell, its influence on the grade
and recovery is observed to be less than that of gas
flux and bias. It is recommended to adjust the feed
flux based on operational needs such as throughput
and product rate
• This study showed that wash water doesn’t directly
impact the recovery and grade. However, it’s worth
mentioning that it is an important parameter for
bias adjustment. Therefore, it is advisable to consider
the influence of bias on the grade and recovery while
adjusting wash water based on water consumption
needs
• The optimum ranges for the parameters can be sum-
marized as follows: 1.0 jg 2.0 0.15 jb 0.35 3.5
jf 4.5 and 0.9 jw 1.2. The decision hierarchy
should be developed with an initial determination
of gas flux, followed by bias. Subsequently, based on
operational conditions (e.g., water consumption or
product rate), the feed flux and then wash water flux
should be determined.
In addition to the factors already considered in this study,
other important parameters should be included in the
investigation of RFC. Specifically, the position of the down-
comer and the distance between lamellas are key structural
elements in RFC. Future studies should incorporate these
parameters, along with particle size distribution, to enable
a more comprehensive and thorough understanding of
RFC’s functionality.
ACKNOWLEDGMENTS
This activity has received funding from the European
Institute of Innovation and Technology (EIT), a body
of the European Union, under Horizon 2020, the EU
Framework Programme for Research and Innovation (proj-
ect RFC-Upscaling: New Reflux Flotation Cell Technology
Upscaling for Ore Flotation, project number: 999407100).
We extend our special thanks to Ozan Kokkilic for his
invaluable assistance in both the theoretical and practi-
cal implementation of the Design of Experiment concept.
Additionally, we express our gratitude to Steinar L. Ellefmo
for his support for the DoE study. We also acknowl-
edge FLS (Bartosz Dabrowski, Clay Macomber, Lance
Christodoulou) for providing the RFC, KGHM (Marcin
Czekajło) for supplying copper ore for testing, and Solvay
(Tarun Bhambhani) for providing reagents. Our heartfelt
thanks go to Camilo Mena Silva, Kornel Mateusz Tobiczyk,
Gustav Ward, Jesper Hansen Levinsen, Evy Eilin Stamnes
Valås, and Tobias Holen Kokkin from NTNU for their
continuous assistance.
REFERENCES
Boycott, A. E. (1920). Sedimentation of Blood
Corpuscles. Nature, 104(2621), Article 2621. doi:
10.1038/104532b0.
Carter, R. A. (2017). Floating points: Engineering, geology,
mineralogy, metallurgy, chemistry, etc. Engineering and
Mining Journal, 218(3), 46–49. Retrieved from https://
www.proquest.com/scholarly-journals/floating-points
/docview/1891749585/se-2.
(Finch and Dobby, 2001). Similar outcomes were obtained
in this study a relatively higher bias was necessary to obtain
a satisfactory grade in concentrate. The bias range of 0.2 to
0.4 was identified as the ideal range for RFC with the mate-
rial used in this study. It’s important to remember that the
optimum bias rate is highly dependent on the type of mate-
rial, circuit type, and targeted residence time. In this study,
the flotation time was 15 minutes, which was longer than
typical for lab-scale copper sulfide flotation. It should be
noted again that, due to recirculation, the flotation experi-
ments were quite different from those conducted in a lab-
scale mechanical flotation cell. Consequently, the preferred
bias should be different based on the flotation time. A simi-
lar conclusion can be drawn when variables such as particle
size distribution and circuit type are changed.
CONCLUSIONS
In this research, an optimization study for the operating
parameters of the RFC (i.e., feed, gas, and wash water,
and bias fluxes) in copper flotation utilizing ore from the
KGHM Polkowice Copper Concentrator was successfully
conducted using the Box–Behnken design (BBD) within
the Design of Experiments (DOE) framework. The model
outputs provided by the DOE corroborated findings from
the literature and insights from experimental works at the
NTNU Mineral Processing Lab. The key findings are sum-
marized as follows
• The gas flux is the most influential operating param-
eter for both grade and recovery as it directly deter-
mines the amount of overflow. However, the impact
of gas flux on the recovery is more pronounced than
its effect on the grade. For the Cu grade, the influ-
ence of other parameters becomes significant as well,
reducing the relative contribution of gas flux, even
though it remains the most dominant factor.
• For both grade and recovery, bias was observed as the
second most influential parameter and optimizing
the concentrate grade is a more complex task than
optimizing recovery.
• Even though the feed flux is known to affect the
hydrodynamic of the cell, its influence on the grade
and recovery is observed to be less than that of gas
flux and bias. It is recommended to adjust the feed
flux based on operational needs such as throughput
and product rate
• This study showed that wash water doesn’t directly
impact the recovery and grade. However, it’s worth
mentioning that it is an important parameter for
bias adjustment. Therefore, it is advisable to consider
the influence of bias on the grade and recovery while
adjusting wash water based on water consumption
needs
• The optimum ranges for the parameters can be sum-
marized as follows: 1.0 jg 2.0 0.15 jb 0.35 3.5
jf 4.5 and 0.9 jw 1.2. The decision hierarchy
should be developed with an initial determination
of gas flux, followed by bias. Subsequently, based on
operational conditions (e.g., water consumption or
product rate), the feed flux and then wash water flux
should be determined.
In addition to the factors already considered in this study,
other important parameters should be included in the
investigation of RFC. Specifically, the position of the down-
comer and the distance between lamellas are key structural
elements in RFC. Future studies should incorporate these
parameters, along with particle size distribution, to enable
a more comprehensive and thorough understanding of
RFC’s functionality.
ACKNOWLEDGMENTS
This activity has received funding from the European
Institute of Innovation and Technology (EIT), a body
of the European Union, under Horizon 2020, the EU
Framework Programme for Research and Innovation (proj-
ect RFC-Upscaling: New Reflux Flotation Cell Technology
Upscaling for Ore Flotation, project number: 999407100).
We extend our special thanks to Ozan Kokkilic for his
invaluable assistance in both the theoretical and practi-
cal implementation of the Design of Experiment concept.
Additionally, we express our gratitude to Steinar L. Ellefmo
for his support for the DoE study. We also acknowl-
edge FLS (Bartosz Dabrowski, Clay Macomber, Lance
Christodoulou) for providing the RFC, KGHM (Marcin
Czekajło) for supplying copper ore for testing, and Solvay
(Tarun Bhambhani) for providing reagents. Our heartfelt
thanks go to Camilo Mena Silva, Kornel Mateusz Tobiczyk,
Gustav Ward, Jesper Hansen Levinsen, Evy Eilin Stamnes
Valås, and Tobias Holen Kokkin from NTNU for their
continuous assistance.
REFERENCES
Boycott, A. E. (1920). Sedimentation of Blood
Corpuscles. Nature, 104(2621), Article 2621. doi:
10.1038/104532b0.
Carter, R. A. (2017). Floating points: Engineering, geology,
mineralogy, metallurgy, chemistry, etc. Engineering and
Mining Journal, 218(3), 46–49. Retrieved from https://
www.proquest.com/scholarly-journals/floating-points
/docview/1891749585/se-2.