2830 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
The NovaCell ™ flotation test work was conducted in
a small-scale laboratory rig and the standard test procedure
is described below:
• The ground sample is combined with water to the
desired pulp density and placed in the NovaCell ™
device.
• It is recirculated through the downcomer while
reagents are added to condition the particles.
• Air is then introduced to the system, which starts the
flotation process.
• The froth and screen concentrate samples are col-
lected for the duration of the test.
• At the end of the test, all the remaining solids in the
NovaCell ™ are collected as the tailings sample.
• All collected samples are filtered, screened, dried, and
submitted for chemical analysis. The dry masses and
elemental assays were then used to balance the data
using generalized least squares regression.
To benchmark the NovaCell ™ metallurgical performance
to conventional flotation technology, the sample was also
tested in a laboratory-scale Agitair mechanically agitated
cell. The Agitair cell generally represents the best hydrody-
namic and froth recovery conditions achievable in conven-
tional flotation technology. So, at plant-scale, mechanically
agitated cells with the optimum design in pulp mixing,
pulp suspension, and froth recovery, will likely get close to
the laboratory Agitair recoveries. For this reason, the labo-
ratory Agitair cells (or similar) are routinely used in project
studies to predict the metallurgical performance of plant-
scale mechanically agitated cells. They are also very useful
for optimization work, to identify areas for improvement in
plant-scale flotation equipment.
The flotation conditions for both tests are presented
in Table 2. The aim was to keep the flotation parameters
of particle size, solids density, and chemistry, as consistent
as possible. For both tests, the test time represents the time
taken for the froth to become barren of valuable minerals.
Note, for the NovaCell ™, due to the design of the small-
scale rig, not all the particles are in the contact/collection
zone at the start of the test. Some particles may take up to
6 mins to enter the contact/collection zone. In the Agitair
cell test, all the particles are in the contact/collection zone
at the start of the test.
Case Study 1—Results
At a flotation feed grind size (P80) of 350 µm, the
NovaCell ™ obtained copper and molybdenum recoveries
of 88% and 76%, respectively. For copper, the recovery
split between the froth and screen concentrates were 87%
and 1%, respectively. For molybdenum, the recovery split
was 75% and 1%, respectively. Thus, the screen concentrate
only contributed a minor amount to the product recovery
and the classification circuit would likely not be required
for this application. Note, for coarser flotation feed grind
sizes with P80s above 350 µm, the classification circuit may
be required.
A comparison of the results for the NovaCell ™ and the
Agitair cell are presented in Table 3. The results showed that
the NovaCell ™ achieved a 10% higher copper recovery and
17% higher molybdenum recovery. The NovaCell ™ prod-
uct upgrade ratios were also higher than the Agitair cell. The
product upgrade ratio is defined as the concentrate assay
divided by the feed assay and is used to indicate the min-
eral selectivity to the product stream. Thus, the NovaCell ™
improved both copper recovery and mineral selectivity to
the product streams.
To investigate the copper results further, the NovaCell ™
and Agitair results were analyzed on a sized basis. The cop-
per recovery-by-size results for both tests are presented in
Table 2. Case study 1 summary of flotation conditions
Test Parameter Unit
Test Conditions
NovaCell™ Agitair Cell
System Volume l 22 5
Test time (min) 30 17
Sample Feed Mass kg 8.0 2.0
Grind Size (P
80 )µm 350 350
Feed Solids Density (%w/w) 31% 31%
Screen Aperture µm 212 n/a
Collector (17A) g/t 7 7
Collector (PAX) g/t 14 14
Frother (MIBC) ppm (vol) 26 26
pH (Lime) — 8.1 8.1
Eh (NaHS) mV (Ag/AgCl) +199 +154
The NovaCell ™ flotation test work was conducted in
a small-scale laboratory rig and the standard test procedure
is described below:
• The ground sample is combined with water to the
desired pulp density and placed in the NovaCell ™
device.
• It is recirculated through the downcomer while
reagents are added to condition the particles.
• Air is then introduced to the system, which starts the
flotation process.
• The froth and screen concentrate samples are col-
lected for the duration of the test.
• At the end of the test, all the remaining solids in the
NovaCell ™ are collected as the tailings sample.
• All collected samples are filtered, screened, dried, and
submitted for chemical analysis. The dry masses and
elemental assays were then used to balance the data
using generalized least squares regression.
To benchmark the NovaCell ™ metallurgical performance
to conventional flotation technology, the sample was also
tested in a laboratory-scale Agitair mechanically agitated
cell. The Agitair cell generally represents the best hydrody-
namic and froth recovery conditions achievable in conven-
tional flotation technology. So, at plant-scale, mechanically
agitated cells with the optimum design in pulp mixing,
pulp suspension, and froth recovery, will likely get close to
the laboratory Agitair recoveries. For this reason, the labo-
ratory Agitair cells (or similar) are routinely used in project
studies to predict the metallurgical performance of plant-
scale mechanically agitated cells. They are also very useful
for optimization work, to identify areas for improvement in
plant-scale flotation equipment.
The flotation conditions for both tests are presented
in Table 2. The aim was to keep the flotation parameters
of particle size, solids density, and chemistry, as consistent
as possible. For both tests, the test time represents the time
taken for the froth to become barren of valuable minerals.
Note, for the NovaCell ™, due to the design of the small-
scale rig, not all the particles are in the contact/collection
zone at the start of the test. Some particles may take up to
6 mins to enter the contact/collection zone. In the Agitair
cell test, all the particles are in the contact/collection zone
at the start of the test.
Case Study 1—Results
At a flotation feed grind size (P80) of 350 µm, the
NovaCell ™ obtained copper and molybdenum recoveries
of 88% and 76%, respectively. For copper, the recovery
split between the froth and screen concentrates were 87%
and 1%, respectively. For molybdenum, the recovery split
was 75% and 1%, respectively. Thus, the screen concentrate
only contributed a minor amount to the product recovery
and the classification circuit would likely not be required
for this application. Note, for coarser flotation feed grind
sizes with P80s above 350 µm, the classification circuit may
be required.
A comparison of the results for the NovaCell ™ and the
Agitair cell are presented in Table 3. The results showed that
the NovaCell ™ achieved a 10% higher copper recovery and
17% higher molybdenum recovery. The NovaCell ™ prod-
uct upgrade ratios were also higher than the Agitair cell. The
product upgrade ratio is defined as the concentrate assay
divided by the feed assay and is used to indicate the min-
eral selectivity to the product stream. Thus, the NovaCell ™
improved both copper recovery and mineral selectivity to
the product streams.
To investigate the copper results further, the NovaCell ™
and Agitair results were analyzed on a sized basis. The cop-
per recovery-by-size results for both tests are presented in
Table 2. Case study 1 summary of flotation conditions
Test Parameter Unit
Test Conditions
NovaCell™ Agitair Cell
System Volume l 22 5
Test time (min) 30 17
Sample Feed Mass kg 8.0 2.0
Grind Size (P
80 )µm 350 350
Feed Solids Density (%w/w) 31% 31%
Screen Aperture µm 212 n/a
Collector (17A) g/t 7 7
Collector (PAX) g/t 14 14
Frother (MIBC) ppm (vol) 26 26
pH (Lime) — 8.1 8.1
Eh (NaHS) mV (Ag/AgCl) +199 +154