XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2361
from 10% to 8% would undoubtedly result in a reduction
in Cu recovery. However, in this case, because the ore was
very well behaved, i.e., very fast flotation kinetics, we did
not see a difference in the Cu recovery.
Critical Coalescence Concentration (CCC)
Measurements
One measure of the efficacy of a frother is the critical coales-
cence concentration (CCC). Simply put, it reflects the con-
centration of the frother needed to achieve the minimum
bubble size possible. Strong frothers have a lower CCC, i.e.,
the dosage required to achieve the minimum bubble size
is lower, as compared to a weaker frother, which shows a
greater value of the CCC. Almost all the species present in
the water (metal ions, collectors, ore and species released
from it, modifiers added) will affect the CCC, so the value
is specific to the system being evaluated. The CCC is a use-
ful tool to rank frothers in terms of their strength but has
limited use in frother selection and optimization that is
best determined through minimal bench-scale testing and
monitoring attributes such as recovery of gangue and water,
followed by optimization at plant scale.
In this work, we seek to use the CCC to determine the
critical coalescence concentration of the two Transfoamer ™
products to demonstrate the weakening over time. The
measurements are conducted at pH 11.5 in tap water, with
lime (Ca(OH)2) as the pH modifier. The doses of frother
Table 2. Results from T-100 run compared to a formulation of strong/weak frother (20/80, as is typical)
Rougher Mass Rec (%)Cu Assay (%)Cu Rec (%)
Transfoamer™ T-100 10 2.6 96.7
Medium Strength Blend 8.1 3.4 96.8
Cleaner Concentrate (Cumulative) Mass Rec (%)Cu Assay (%)Cu Rec (%)
Transfoamer™ T-100 2 12.6 94.6
Medium strength Blend 1.9 13.9 95.1
used are 2, 5, 12 and 18ul/L. A key difference is that we
conducted the experiments immediately, and after a 30
minute delay to allow for the frother “switch” from strong
to weak. The experiments were conducted using the McGill
bubble sizer, a well-known tool for conducting bubble size
measurements. The D32 averages obtained over each test
were then plotted and the CCC95 was estimated using the
graphical method described in detail in Laskowski (2003).
The charts in Figure 2 and 3 illustrate the bubble size
data and the fit obtained for the Transfoamer ™ T-100 and
T-200 frothers respectively. For T-100, we that the CCC
is calculated to be approximately 12.5ul/L when the test
is conducted immediately after raising the pH. After wait-
ing for 30 minutes, the CCC decreases to approximately
20ul/L or more frother concentration needed to approach
the minimum, indicating the frother has switched from
strong to weak. Similarly, for the T-200 frother, we observe
the CCC to be about 6ul/L when the test was conducted
immediately after raising the pH and it increases to over
14ul/L after a 30 minute delay. This suggests both frothers
are “switching” from strong to weak at pH 11.5.
CONCLUSIONS
Mines are looking to increase throughput, resulting in a
coarse particle size distribution in the feed. Floating coarse
particles requires strong frothers, which carry over to the
cleaners causing problems such as deep froths (reduction
Figure 2. Critical coalescence concentration (CCC95) values for Transfoamer™ T-100 frother
from 10% to 8% would undoubtedly result in a reduction
in Cu recovery. However, in this case, because the ore was
very well behaved, i.e., very fast flotation kinetics, we did
not see a difference in the Cu recovery.
Critical Coalescence Concentration (CCC)
Measurements
One measure of the efficacy of a frother is the critical coales-
cence concentration (CCC). Simply put, it reflects the con-
centration of the frother needed to achieve the minimum
bubble size possible. Strong frothers have a lower CCC, i.e.,
the dosage required to achieve the minimum bubble size
is lower, as compared to a weaker frother, which shows a
greater value of the CCC. Almost all the species present in
the water (metal ions, collectors, ore and species released
from it, modifiers added) will affect the CCC, so the value
is specific to the system being evaluated. The CCC is a use-
ful tool to rank frothers in terms of their strength but has
limited use in frother selection and optimization that is
best determined through minimal bench-scale testing and
monitoring attributes such as recovery of gangue and water,
followed by optimization at plant scale.
In this work, we seek to use the CCC to determine the
critical coalescence concentration of the two Transfoamer ™
products to demonstrate the weakening over time. The
measurements are conducted at pH 11.5 in tap water, with
lime (Ca(OH)2) as the pH modifier. The doses of frother
Table 2. Results from T-100 run compared to a formulation of strong/weak frother (20/80, as is typical)
Rougher Mass Rec (%)Cu Assay (%)Cu Rec (%)
Transfoamer™ T-100 10 2.6 96.7
Medium Strength Blend 8.1 3.4 96.8
Cleaner Concentrate (Cumulative) Mass Rec (%)Cu Assay (%)Cu Rec (%)
Transfoamer™ T-100 2 12.6 94.6
Medium strength Blend 1.9 13.9 95.1
used are 2, 5, 12 and 18ul/L. A key difference is that we
conducted the experiments immediately, and after a 30
minute delay to allow for the frother “switch” from strong
to weak. The experiments were conducted using the McGill
bubble sizer, a well-known tool for conducting bubble size
measurements. The D32 averages obtained over each test
were then plotted and the CCC95 was estimated using the
graphical method described in detail in Laskowski (2003).
The charts in Figure 2 and 3 illustrate the bubble size
data and the fit obtained for the Transfoamer ™ T-100 and
T-200 frothers respectively. For T-100, we that the CCC
is calculated to be approximately 12.5ul/L when the test
is conducted immediately after raising the pH. After wait-
ing for 30 minutes, the CCC decreases to approximately
20ul/L or more frother concentration needed to approach
the minimum, indicating the frother has switched from
strong to weak. Similarly, for the T-200 frother, we observe
the CCC to be about 6ul/L when the test was conducted
immediately after raising the pH and it increases to over
14ul/L after a 30 minute delay. This suggests both frothers
are “switching” from strong to weak at pH 11.5.
CONCLUSIONS
Mines are looking to increase throughput, resulting in a
coarse particle size distribution in the feed. Floating coarse
particles requires strong frothers, which carry over to the
cleaners causing problems such as deep froths (reduction
Figure 2. Critical coalescence concentration (CCC95) values for Transfoamer™ T-100 frother