XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2355
fines (–38µm) recovery is the same for all dosing methods.
Compared to the no collector test, a little collector increases
fines recovery by approximately 1.5% for all dosing meth-
ods. This percentage increase increases quite significantly
with particle size for the zero- and aero methods showing a
14% (batch), 25% (zero) and 36% (aero) recovery increase
for the middling size class, and a 0% (batch), 29% (zero)
and 96% (aero) recovery increase for the coarse size class
when compared with the no collector test. Figure 4 illus-
trates that for the low dosage level, the distribution of cop-
per in the coarser size classes is materially higher for the
zero- and aero dosing methods than for the batch and no
collector tests. These results show that when collector is
available in limited quantities, the zero- and aero dosing
methods are better able to recover coarser particles than
the batch method. This result suggests that coarse particles
in the zero- and aero system are more hydrophobic than
coarse particles in the batch system.
SUMMARY AND CONCLUSIONS
The ore used in this study exhibits a high degree of natu-
ral floatability, achieving a copper recovery of 51% without
the addition of collector.
The results show that when collector dosage rates are
at the ‘near overdosing’ level, the collector dosing method
has no effect on the final recovery achieved. All the dos-
age methods achieve a similar high overall copper recovery
in excess of 90%. On a by size basis, the copper recovery
is very high for the fines (~97%) and middlings (~96%)
classes and slightly less for the coarse (~86%) class.
When the system is starved of collector, the different
dosing methods show differing copper recoveries, with the
aero- and zero methods recovering more copper than the
batch method, particularly in the coarser size classes. The
zero- (57%) and aero (61%) methovds achieve higher over-
all copper recoveries than the batch (54%). The recovery
by size data makes it clear that the zero- and aero methods
recover significantly more copper in the coarser size classes
than the batch method. For the coarse class, the batch (9%)
copper recovery is slightly better than the recovery with no
collector (7%), but is nearly doubled for the aero (18%)
method. For the middlings class, the aero (82%) and zero
(76%) methods achieve modest copper recoveries com-
pared to the batch (69%) method and no collector (59%).
These results do not show the same levels of improve-
ment demonstrated by Patil and Laskowski (2008) and
Nott and Manlapig (1994) when using aerosol and zero-
conditioning collector dosing methods. Nevertheless, this
does not disprove the concept that aerosol collector dos-
ing is potentially beneficial. The ore is highly floatable, and
some of the effects are likely masked. The improvement in
coarse particle recovery is a further indication that this will
potentially work better in a coarser system.
The results agree with the work by Bazin and Proulx
(2001) showing that down-the-bank collector dosing has
little effect on the recovery of fine particles but is effective
in increasing coarse particle recovery. The zero- and aero
methods in this study are similar to down-the-bank dosing,
in that the collector concentration increases with time. In
this study, while both the zero- and aero methods produced
improved coarse particle recoveries when compared to the
batch method, the aero method produced better coarse par-
ticle recoveries when compared to the zero method. This
difference is likely a result of the higher degree of collector
adsorption from the solid-gas interface when using the aero
method. Additionally, bubble-particle collision probability
Table 1. Copper recovery for the different dosing methods for the fine (–38µm),
middling (–38µm to +75µm) and coarse (+75µm) size classes at low and high collector
dosage rates
Copper Recovery (%)by Size
Fine
–38µm
Middling
–38µm to +75µm
Coarse
+75µm
High dose
Batch 97.4 ± 0.2 96.8 ± 0.8 88.3 ± 3.2
Zero 97.0 ± 0.4 95.8 ± 1.1 83.0 ± 3.6
Aero 97.2 ± 0.3 96.8 ± 1.7 87.7 ± 4.5
Low dose
Batch 95.6 ± 0.3 69.1 ± 0.8 9.5 ± 0.4
Zero 95.2 ± 0.3 75.9 ± 0.9 12.2 ± 0.5
Aero 95.5 ± 0.3 82.1 ± 1.0 18.0 ± 0.8
No Collector 94.7 ± 0.6 59.1 ± 0.5 7.4 ± 3.3
fines (–38µm) recovery is the same for all dosing methods.
Compared to the no collector test, a little collector increases
fines recovery by approximately 1.5% for all dosing meth-
ods. This percentage increase increases quite significantly
with particle size for the zero- and aero methods showing a
14% (batch), 25% (zero) and 36% (aero) recovery increase
for the middling size class, and a 0% (batch), 29% (zero)
and 96% (aero) recovery increase for the coarse size class
when compared with the no collector test. Figure 4 illus-
trates that for the low dosage level, the distribution of cop-
per in the coarser size classes is materially higher for the
zero- and aero dosing methods than for the batch and no
collector tests. These results show that when collector is
available in limited quantities, the zero- and aero dosing
methods are better able to recover coarser particles than
the batch method. This result suggests that coarse particles
in the zero- and aero system are more hydrophobic than
coarse particles in the batch system.
SUMMARY AND CONCLUSIONS
The ore used in this study exhibits a high degree of natu-
ral floatability, achieving a copper recovery of 51% without
the addition of collector.
The results show that when collector dosage rates are
at the ‘near overdosing’ level, the collector dosing method
has no effect on the final recovery achieved. All the dos-
age methods achieve a similar high overall copper recovery
in excess of 90%. On a by size basis, the copper recovery
is very high for the fines (~97%) and middlings (~96%)
classes and slightly less for the coarse (~86%) class.
When the system is starved of collector, the different
dosing methods show differing copper recoveries, with the
aero- and zero methods recovering more copper than the
batch method, particularly in the coarser size classes. The
zero- (57%) and aero (61%) methovds achieve higher over-
all copper recoveries than the batch (54%). The recovery
by size data makes it clear that the zero- and aero methods
recover significantly more copper in the coarser size classes
than the batch method. For the coarse class, the batch (9%)
copper recovery is slightly better than the recovery with no
collector (7%), but is nearly doubled for the aero (18%)
method. For the middlings class, the aero (82%) and zero
(76%) methods achieve modest copper recoveries com-
pared to the batch (69%) method and no collector (59%).
These results do not show the same levels of improve-
ment demonstrated by Patil and Laskowski (2008) and
Nott and Manlapig (1994) when using aerosol and zero-
conditioning collector dosing methods. Nevertheless, this
does not disprove the concept that aerosol collector dos-
ing is potentially beneficial. The ore is highly floatable, and
some of the effects are likely masked. The improvement in
coarse particle recovery is a further indication that this will
potentially work better in a coarser system.
The results agree with the work by Bazin and Proulx
(2001) showing that down-the-bank collector dosing has
little effect on the recovery of fine particles but is effective
in increasing coarse particle recovery. The zero- and aero
methods in this study are similar to down-the-bank dosing,
in that the collector concentration increases with time. In
this study, while both the zero- and aero methods produced
improved coarse particle recoveries when compared to the
batch method, the aero method produced better coarse par-
ticle recoveries when compared to the zero method. This
difference is likely a result of the higher degree of collector
adsorption from the solid-gas interface when using the aero
method. Additionally, bubble-particle collision probability
Table 1. Copper recovery for the different dosing methods for the fine (–38µm),
middling (–38µm to +75µm) and coarse (+75µm) size classes at low and high collector
dosage rates
Copper Recovery (%)by Size
Fine
–38µm
Middling
–38µm to +75µm
Coarse
+75µm
High dose
Batch 97.4 ± 0.2 96.8 ± 0.8 88.3 ± 3.2
Zero 97.0 ± 0.4 95.8 ± 1.1 83.0 ± 3.6
Aero 97.2 ± 0.3 96.8 ± 1.7 87.7 ± 4.5
Low dose
Batch 95.6 ± 0.3 69.1 ± 0.8 9.5 ± 0.4
Zero 95.2 ± 0.3 75.9 ± 0.9 12.2 ± 0.5
Aero 95.5 ± 0.3 82.1 ± 1.0 18.0 ± 0.8
No Collector 94.7 ± 0.6 59.1 ± 0.5 7.4 ± 3.3