2864 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
MIBC dosage varied between 10 and 400 ppm for each
test. Approximately 300 images were captured for every
test. Figure 4 illustrates the setup of the JKHFmini with
the PVM probe.
In the JKHFmini, the bubble generation mechanism
consists of an air sparger and a sintered disc. The sintered
disc prevents solids from moving from the top chamber of
the cylinder to the plenum at the bottom, which can lead to
the blockage of the air-sparger pores (Verster et al., 2023).
Additionally, the sintered disc has a direct influence on the
bubble formation process. However, the disc itself acts as
an additional source of bubble coalescence, thereby influ-
encing the overall bubble size. The minimum theoretical
bubble size is influenced by the size of the disc’s pores size.
RESULTS
Effect of the frother dosage on bubble diameter
Figure 5 illustrates the bubble size as a function of the
MIBC dosage for the tested airflow conditions. It can be
seen that the bubble size decreases with an increase in the
frother concentration across all superficial gas velocities.
For each value of Jg, the bubble size reaches a plateau at
the minimum D32, corresponding to the CCC value. The
concentration at which the CCC is reached increases with
increasing Jg. Moreover, the minimum bubble size obtained
at CCC increases with increasing Jg.
The D32 data displays a high level of scatter, indicated
by wide error bars. For this reason, the exact values of CCC
can be hard to determine. However, CCC values can be
roughly estimated to lie between 100 and 200 ppm. At
the CCC values, the Sauter mean diameter of the bubbles
ranged between 0.37 to 0.45. These values are commensu-
rable to the bubble size values presented by K. Demir, A.J.
Morrison, C. Evans et al. (2023). However, bubble size in
any flotation device is strongly influenced by the bubble
generation mechanism. Therefore, measured bubble sizes
should not be compared directly.
Effect of frother dosage on bubble surface area flux
Figure 6 shows the relationship between the bubble sur-
face area flux (Sb) and the frother dosage across the tested
airflow conditions. Across all superficial gas velocities, Sb
increases as the frother concentration is raised. Additionally,
Sb significantly increases with an increase in superficial gas
velocity. Regardless of the specific superficial gas velocity
(Jg) values, Sb reaches a plateau, indicating the attainment
of the maximum Sb value. The Sb value at which the plateau
is reached increases with higher Jg. Further analysis of the
data to take Sb values into account results in a smoother
Figure 4. An experimental setup was done with JKFHmini and a PVM probe
MIBC dosage varied between 10 and 400 ppm for each
test. Approximately 300 images were captured for every
test. Figure 4 illustrates the setup of the JKHFmini with
the PVM probe.
In the JKHFmini, the bubble generation mechanism
consists of an air sparger and a sintered disc. The sintered
disc prevents solids from moving from the top chamber of
the cylinder to the plenum at the bottom, which can lead to
the blockage of the air-sparger pores (Verster et al., 2023).
Additionally, the sintered disc has a direct influence on the
bubble formation process. However, the disc itself acts as
an additional source of bubble coalescence, thereby influ-
encing the overall bubble size. The minimum theoretical
bubble size is influenced by the size of the disc’s pores size.
RESULTS
Effect of the frother dosage on bubble diameter
Figure 5 illustrates the bubble size as a function of the
MIBC dosage for the tested airflow conditions. It can be
seen that the bubble size decreases with an increase in the
frother concentration across all superficial gas velocities.
For each value of Jg, the bubble size reaches a plateau at
the minimum D32, corresponding to the CCC value. The
concentration at which the CCC is reached increases with
increasing Jg. Moreover, the minimum bubble size obtained
at CCC increases with increasing Jg.
The D32 data displays a high level of scatter, indicated
by wide error bars. For this reason, the exact values of CCC
can be hard to determine. However, CCC values can be
roughly estimated to lie between 100 and 200 ppm. At
the CCC values, the Sauter mean diameter of the bubbles
ranged between 0.37 to 0.45. These values are commensu-
rable to the bubble size values presented by K. Demir, A.J.
Morrison, C. Evans et al. (2023). However, bubble size in
any flotation device is strongly influenced by the bubble
generation mechanism. Therefore, measured bubble sizes
should not be compared directly.
Effect of frother dosage on bubble surface area flux
Figure 6 shows the relationship between the bubble sur-
face area flux (Sb) and the frother dosage across the tested
airflow conditions. Across all superficial gas velocities, Sb
increases as the frother concentration is raised. Additionally,
Sb significantly increases with an increase in superficial gas
velocity. Regardless of the specific superficial gas velocity
(Jg) values, Sb reaches a plateau, indicating the attainment
of the maximum Sb value. The Sb value at which the plateau
is reached increases with higher Jg. Further analysis of the
data to take Sb values into account results in a smoother
Figure 4. An experimental setup was done with JKFHmini and a PVM probe