2852 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
plant covers approximately one-quarter of the KGHM total
ore beneficiation volume. The Polkowice plant is divided
into three technology lines, with a processing capacity of
approx. 290 t/h, 440 t/h, and 390 t/h, respectively. Each
line includes grinding and classification sections compris-
ing ball mills, spiral classifiers, and primary hydrocyclones.
The classified feed is processed in rougher flotation, fol-
lowed by a scavenger and three stages of cleaning flotation.
The rougher tailings are classified in secondary hydrocy-
clones, while firstcleaning tailings are in the third stage of
hydrocyclones. Overflow of secondary and third hydro-
cyclones is directed to scavenger flotation and underflow,
after regrinding, back to rougher. The three-staged cleaning
flotation finally produces the copper concentrate grade of
about 24.5% Cu.
The mechanical tank cells are used for the whole flo-
tation plant, i.e., 48 m3 cells for rougher and scavenger,
the first and second cleaner stages using 30 m3 tank cells
and 20 m3 used in the third cleaning stage. The mixture
of ethyl and isobutyl sodium xanthates is used as a collec-
tor. Polyglycol alkyl ethers are used as a frother. Due to
the fine-grained nature of the ore, mostly dispersed in the
black-shale matrix, fine grinding is required, especially in
the regrinding circuit that feeds the scavenger flotation.
It causes the risk of overgrinding which negatively affects
copper recovery. Moreover, during the grinding process,
organicrich shales release the grains of the total organic
carbon matter, which have a similar flotation behavior to
copper sulfides and thus affect selectivity (i.e., copper con-
centrate grade). Many attempts have been made to improve
flotation performance, especially in the design of aerator
units, introducing new collectors, and depressing organic
carbon compounds. Despite the many efforts, the recovery
of fine particles remains a challenge.
It is widely known that in conventional mechanical
tank cells, an extremely energy-consuming process must be
applied in the generation of high shear for particle-bubble
collision, especially as the conventional tanks become larger
(Hassanzadeh et al., 2018 Safari et al., 2017 Schubert,
2008). Pneumatic flotation has been demonstrated to be
more effective than conventional cells in terms of recov-
ering fine particles (Battersby et al., 2011 Hoang et al.,
2022).
The Horizon 2020 FineFuture project researched inno-
vative technologies and concepts for the recovery of ultra-
fine particles in which current flotation technologies do not
work adequately. Different technologies have been tested
on a smaller scale and one of the promising concepts is a
pneumatic reactor-separator based on Maelgwyn Imhoflot’s
pneumatic G-Cell, which was chosen for the upscaling test
onsite at the KGHM concentrator.
This study aims to better understand the influence of
different operating conditions of Imhoflot pneumatic flota-
tion cells, namely froth height and recirculation load, on the
recovery behavior of different minerals from this complex
copper ore. This evaluation is done based on the recovery
behavior of individual particles, computed with particle-
based models (PSMs, Pereira et al., 2021), as a function of
their size, shape, liberation, and association.
METHODOLOGY
Imhoflot Pneumatic Pilot Plant Test Work
The testwork was conducted using a semi-industrial pneu-
matic Imhoflot G-14 cell (tangential feed to the separator
vessel) with a 1.4 m diameter, and throughput is 20 -30
m3/h at KGHM Polkowice plant, Poland. The pilot plant
trials were tested on the first technology line, i.e., 290 t/h,
and on the scavenger feed streamline under various oper-
ating parameters (froth height and recycling load). Other
parameters, such as fresh feed, feed, and tailings flow rate
air flow rate, feed and air pressure and pulp level were
measured and controlled by a PLC control with an HMI
touchscreen.
The pulp level or froth height was controlled by a level
transmitter at the bottom cone of the cell which links to the
frequency inverter of the tailings pump P03 (cf. Figure 1).
The pilot plant is designed with the option of recycling.
Depending on the stream and duty, target recovery, or
grade it could be varied. For example, the more recycling
load, the higher recovery as expected but the grade will
probably be reduced.
The samples were taken simultaneously by two persons
from four different sampling points, i.e., fresh feed, recycle,
concentrate, and tailings. (cf. Figure 1). The sampling only
takes place as long as the plant maintains a steady state (gen-
erally after 30 min). The sub-samples were taken every 15
min for two hours, then the bulk samples were weighed, fil-
tered, and prepared for the chemical assays and wet sieving.
Pilot test conditions are the following:
• Streamline: Scavenger feed, d80 ca. 75 µm, and about
56.6% particle below 20 µm. Cu content ca.
• 2.25%.
• Feed flow rate: 20 m3/h.
• Air flow rate: 15 m3/h.
• Froth height hF: deep (60% pulp level, hF ca. 400
mm) middle (70% pulp level, hF ca. 200 mm) and
shallow froth (80% pulp level, hF ca. 50 mm)
plant covers approximately one-quarter of the KGHM total
ore beneficiation volume. The Polkowice plant is divided
into three technology lines, with a processing capacity of
approx. 290 t/h, 440 t/h, and 390 t/h, respectively. Each
line includes grinding and classification sections compris-
ing ball mills, spiral classifiers, and primary hydrocyclones.
The classified feed is processed in rougher flotation, fol-
lowed by a scavenger and three stages of cleaning flotation.
The rougher tailings are classified in secondary hydrocy-
clones, while firstcleaning tailings are in the third stage of
hydrocyclones. Overflow of secondary and third hydro-
cyclones is directed to scavenger flotation and underflow,
after regrinding, back to rougher. The three-staged cleaning
flotation finally produces the copper concentrate grade of
about 24.5% Cu.
The mechanical tank cells are used for the whole flo-
tation plant, i.e., 48 m3 cells for rougher and scavenger,
the first and second cleaner stages using 30 m3 tank cells
and 20 m3 used in the third cleaning stage. The mixture
of ethyl and isobutyl sodium xanthates is used as a collec-
tor. Polyglycol alkyl ethers are used as a frother. Due to
the fine-grained nature of the ore, mostly dispersed in the
black-shale matrix, fine grinding is required, especially in
the regrinding circuit that feeds the scavenger flotation.
It causes the risk of overgrinding which negatively affects
copper recovery. Moreover, during the grinding process,
organicrich shales release the grains of the total organic
carbon matter, which have a similar flotation behavior to
copper sulfides and thus affect selectivity (i.e., copper con-
centrate grade). Many attempts have been made to improve
flotation performance, especially in the design of aerator
units, introducing new collectors, and depressing organic
carbon compounds. Despite the many efforts, the recovery
of fine particles remains a challenge.
It is widely known that in conventional mechanical
tank cells, an extremely energy-consuming process must be
applied in the generation of high shear for particle-bubble
collision, especially as the conventional tanks become larger
(Hassanzadeh et al., 2018 Safari et al., 2017 Schubert,
2008). Pneumatic flotation has been demonstrated to be
more effective than conventional cells in terms of recov-
ering fine particles (Battersby et al., 2011 Hoang et al.,
2022).
The Horizon 2020 FineFuture project researched inno-
vative technologies and concepts for the recovery of ultra-
fine particles in which current flotation technologies do not
work adequately. Different technologies have been tested
on a smaller scale and one of the promising concepts is a
pneumatic reactor-separator based on Maelgwyn Imhoflot’s
pneumatic G-Cell, which was chosen for the upscaling test
onsite at the KGHM concentrator.
This study aims to better understand the influence of
different operating conditions of Imhoflot pneumatic flota-
tion cells, namely froth height and recirculation load, on the
recovery behavior of different minerals from this complex
copper ore. This evaluation is done based on the recovery
behavior of individual particles, computed with particle-
based models (PSMs, Pereira et al., 2021), as a function of
their size, shape, liberation, and association.
METHODOLOGY
Imhoflot Pneumatic Pilot Plant Test Work
The testwork was conducted using a semi-industrial pneu-
matic Imhoflot G-14 cell (tangential feed to the separator
vessel) with a 1.4 m diameter, and throughput is 20 -30
m3/h at KGHM Polkowice plant, Poland. The pilot plant
trials were tested on the first technology line, i.e., 290 t/h,
and on the scavenger feed streamline under various oper-
ating parameters (froth height and recycling load). Other
parameters, such as fresh feed, feed, and tailings flow rate
air flow rate, feed and air pressure and pulp level were
measured and controlled by a PLC control with an HMI
touchscreen.
The pulp level or froth height was controlled by a level
transmitter at the bottom cone of the cell which links to the
frequency inverter of the tailings pump P03 (cf. Figure 1).
The pilot plant is designed with the option of recycling.
Depending on the stream and duty, target recovery, or
grade it could be varied. For example, the more recycling
load, the higher recovery as expected but the grade will
probably be reduced.
The samples were taken simultaneously by two persons
from four different sampling points, i.e., fresh feed, recycle,
concentrate, and tailings. (cf. Figure 1). The sampling only
takes place as long as the plant maintains a steady state (gen-
erally after 30 min). The sub-samples were taken every 15
min for two hours, then the bulk samples were weighed, fil-
tered, and prepared for the chemical assays and wet sieving.
Pilot test conditions are the following:
• Streamline: Scavenger feed, d80 ca. 75 µm, and about
56.6% particle below 20 µm. Cu content ca.
• 2.25%.
• Feed flow rate: 20 m3/h.
• Air flow rate: 15 m3/h.
• Froth height hF: deep (60% pulp level, hF ca. 400
mm) middle (70% pulp level, hF ca. 200 mm) and
shallow froth (80% pulp level, hF ca. 50 mm)