XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2569
2024). In the present work, the Super Collectors have
been tested in the laboratory flotation tests. The impact of
these Super Collectors on a full-scale flotation circuit has
also been simulated using a first principles flotation model
(Huang et al., 2022).
EXPERIMENTAL
Fine Particles Flotation
In a closed-flotation circuit, cleaner scavenger tails (CST)
are usually recycled back as circulating load (CL) to the
flotation rougher bank as this stream represents the con-
gregation of the least hydrophobic copper-bearing mineral
particles. These include ultra-fine particles below 20 µm,
poorly liberated particles despite their small particle sizes,
and superficially oxidized particles during their long reten-
tion times. Usually, CST accounts for 20–25% of the total
volumetric flows to the rougher bank and, therefore, limits
throughput.
In this regard, a CST sample was collected from a large
copper flotation plant and was subjected to laboratory
flotation tests using a Super Collector (SC). The oxidized
surfaces of the copper sulfide mineral particles present in
the CST sample were cleaned by grinding in an attrition
mill. The mill product with d80 =10.7 µm was split into
two samples with one used for a control test using 100 g/t
KAX as a collector. In another, 50 g/t of Super Collector
was used in addition to 100 g/t KAX and tested using a
1-L Denver laboratory flotation cell with methyl iso-butyl
carbinol (MIBC) as a frother.
Coarse Particles Flotation
Copper recovery is usually low at particle sizes above
150 µm due mainly to the sharp decrease in mineral libera-
tion (Clark et al., 2006). To address this issue, we subjected
a coarse fraction (–600+212 µm) of a rougher feed sample
to two sets of flotation tests using Super Collectors in a 1-L
Denver laboratory flotation cell. The rougher feed sample
was obtained from a large low-grade porphyry copper flota-
tion circuit. The coarse fraction assayed 0.135%Cu.
In one set of tests, the coarse fraction was floated with
KAX as the primary collector. In each set, three different
tests were conducted: i) KAX alone, ii) KAX plus SC-1 or
SC-2, and iii) KAX plus SC-3. These tests were run at a pH
of 11.0 for 3 minutes with poly-propylene glycol (PPG) as
a frother.
Porphyry Copper Ore Sample Flotation
In the next set of tests, a porphyry copper (Cu) ore sample
was wet-ground in a rod mill for 13 minutes to obtain a d80
=210 µm. The ground sample was conditioned with 50 g/t
KAX in a 2-L Denver laboratory flotation cell. The flota-
tion tests were conducted with or without SC to compare
its performance with KAX. For the SC test, the KAX dos-
age was reduced to 30 g/t to keep the overall reagent dosage
remain constant. The flotation tests were run at pH 11 for
5 minutes with MIBC as a frother. The froth products were
collected at 1, 3, and 5 min flotation times.
RESULTS AND DISCUSSION
Flotation is essentially a macroscopic hydrophobic interac-
tion between two dissimilar surfaces involving a hydropho-
bic mineral 1 and an air bubble 2 in water 3. Yoon et al.
(1997) determined the hydrophobic force constant (K132)
for the asymmetric interactions using a geometric mean
combining rule,
K K K
132 131 232 =[11]
Pazhianur and Yoon (2003) later measured the hydro-
phobic force constants (K131) between two surfaces of
identical contact angles and showed that the symmetric
hydrophobic force constant increases with q. On the other
hand, Wang and Yoon (2009) measured the hydrophobic
forces between two identical air bubbles and showed that
the symmetric hydrophobic force constant (K232) decreases
with increasing frother (electrolyte) concentrations.
Substituting the values of K131 and K232 obtained at a given
q and a frother concentration, one can determine asymmet-
ric hydrophobic force constant (K132) for bubble-particle
interactions in wetting films. In general, K132 decreases
with increasing q and at a lower frother concentration. A
decrease in K132 should in turn create a negative disjoining
pressure (P 0) in the wetting film under consideration,
which is a thermodynamic requirement for flotation. In
kinetic terms, both the energy barrier (E1) and hydrody-
namic resistance (Eh) to film thinning should decrease with
increasing K131.
The results presented in Figure 1 show that the Super
Collector (SC) performed substantially better than KAX in
fine particle flotation. Copper recovery was increased from
26.9 to 44.1%, with a substantial increase in the grade of
the froth product from 3.27 to 7.85%Cu. The improve-
ment of fine particle recovery may allow a plant operator
to consider eliminating CLs and greatly increasing the
throughput, as has been discussed previously in further
detail (Gupta et al., 2023).
According to Eqs. [4] and [6], fine particle flotation
can be improved by i) reducing El in the bubble-particle
attachment step and ii) increasing Ek. The latter approach
has been used in the invention of the Concorde Cell
(Jameson, 2010). The Super Collector addresses the issues
2024). In the present work, the Super Collectors have
been tested in the laboratory flotation tests. The impact of
these Super Collectors on a full-scale flotation circuit has
also been simulated using a first principles flotation model
(Huang et al., 2022).
EXPERIMENTAL
Fine Particles Flotation
In a closed-flotation circuit, cleaner scavenger tails (CST)
are usually recycled back as circulating load (CL) to the
flotation rougher bank as this stream represents the con-
gregation of the least hydrophobic copper-bearing mineral
particles. These include ultra-fine particles below 20 µm,
poorly liberated particles despite their small particle sizes,
and superficially oxidized particles during their long reten-
tion times. Usually, CST accounts for 20–25% of the total
volumetric flows to the rougher bank and, therefore, limits
throughput.
In this regard, a CST sample was collected from a large
copper flotation plant and was subjected to laboratory
flotation tests using a Super Collector (SC). The oxidized
surfaces of the copper sulfide mineral particles present in
the CST sample were cleaned by grinding in an attrition
mill. The mill product with d80 =10.7 µm was split into
two samples with one used for a control test using 100 g/t
KAX as a collector. In another, 50 g/t of Super Collector
was used in addition to 100 g/t KAX and tested using a
1-L Denver laboratory flotation cell with methyl iso-butyl
carbinol (MIBC) as a frother.
Coarse Particles Flotation
Copper recovery is usually low at particle sizes above
150 µm due mainly to the sharp decrease in mineral libera-
tion (Clark et al., 2006). To address this issue, we subjected
a coarse fraction (–600+212 µm) of a rougher feed sample
to two sets of flotation tests using Super Collectors in a 1-L
Denver laboratory flotation cell. The rougher feed sample
was obtained from a large low-grade porphyry copper flota-
tion circuit. The coarse fraction assayed 0.135%Cu.
In one set of tests, the coarse fraction was floated with
KAX as the primary collector. In each set, three different
tests were conducted: i) KAX alone, ii) KAX plus SC-1 or
SC-2, and iii) KAX plus SC-3. These tests were run at a pH
of 11.0 for 3 minutes with poly-propylene glycol (PPG) as
a frother.
Porphyry Copper Ore Sample Flotation
In the next set of tests, a porphyry copper (Cu) ore sample
was wet-ground in a rod mill for 13 minutes to obtain a d80
=210 µm. The ground sample was conditioned with 50 g/t
KAX in a 2-L Denver laboratory flotation cell. The flota-
tion tests were conducted with or without SC to compare
its performance with KAX. For the SC test, the KAX dos-
age was reduced to 30 g/t to keep the overall reagent dosage
remain constant. The flotation tests were run at pH 11 for
5 minutes with MIBC as a frother. The froth products were
collected at 1, 3, and 5 min flotation times.
RESULTS AND DISCUSSION
Flotation is essentially a macroscopic hydrophobic interac-
tion between two dissimilar surfaces involving a hydropho-
bic mineral 1 and an air bubble 2 in water 3. Yoon et al.
(1997) determined the hydrophobic force constant (K132)
for the asymmetric interactions using a geometric mean
combining rule,
K K K
132 131 232 =[11]
Pazhianur and Yoon (2003) later measured the hydro-
phobic force constants (K131) between two surfaces of
identical contact angles and showed that the symmetric
hydrophobic force constant increases with q. On the other
hand, Wang and Yoon (2009) measured the hydrophobic
forces between two identical air bubbles and showed that
the symmetric hydrophobic force constant (K232) decreases
with increasing frother (electrolyte) concentrations.
Substituting the values of K131 and K232 obtained at a given
q and a frother concentration, one can determine asymmet-
ric hydrophobic force constant (K132) for bubble-particle
interactions in wetting films. In general, K132 decreases
with increasing q and at a lower frother concentration. A
decrease in K132 should in turn create a negative disjoining
pressure (P 0) in the wetting film under consideration,
which is a thermodynamic requirement for flotation. In
kinetic terms, both the energy barrier (E1) and hydrody-
namic resistance (Eh) to film thinning should decrease with
increasing K131.
The results presented in Figure 1 show that the Super
Collector (SC) performed substantially better than KAX in
fine particle flotation. Copper recovery was increased from
26.9 to 44.1%, with a substantial increase in the grade of
the froth product from 3.27 to 7.85%Cu. The improve-
ment of fine particle recovery may allow a plant operator
to consider eliminating CLs and greatly increasing the
throughput, as has been discussed previously in further
detail (Gupta et al., 2023).
According to Eqs. [4] and [6], fine particle flotation
can be improved by i) reducing El in the bubble-particle
attachment step and ii) increasing Ek. The latter approach
has been used in the invention of the Concorde Cell
(Jameson, 2010). The Super Collector addresses the issues