2790 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
versa for high pH and anionic collectors. Furthermore, the
surface charge of the bubbles and particles is also affected
by pH, which can affect the interactions between particles
and bubbles (Albijanic et al. 2010).
The effect of 2.0 wt.% NP conditioned with 0.1, 0.3,
and 0.6 CMC CTAB on the dynamics of particle attach-
ment is studied, knowing that there might be a slight addi-
tional influence of the aforementioned parameters (pH,
ionic concentration, and NPs collector). The experiments
are conducted after a waiting time of 1000 s to allow NPs
(acting as ultrafine particles) to adsorb on the bubble surface.
As shown in Figure 5, the K value is significantly increased
by the presence of NPs, and the effect becomes more pro-
nounced as the hydrophobicity of the NPs increases.
The dynamics of particle attachment has been defined
so far by measuring the height or surface area of the cap
over time, with higher K values indicating better particle
collection and flotation performance. While this is true for
systems without NPs, it can be misleading for the systems
with NPs, as the packing density of the particles on the
bubble surface can be significantly reduced by the NPs,
resulting in higher K values that do not necessarily translate
into better flotation performance. This means that the sur-
face coverage can reach its maximum quite quickly, but the
packing density will be low. Therefore, the effect of NPs on
the packing density is investigated in the following.
Figure 6 illustratively shows and compares the packing
density of 66 µm GBs initially dispersed in water solution
and in NP solution (2.0 wt.% NP conditioned with 0.3
CMC CTAB). Again, a waiting time of about 1000 s is
given to ensure sufficient NPs adsorption on the bubble
surface. As it is evident, the presence of NPs at the inter-
face can strongly influence the distribution of the GBs on
the bubble surface. Here, the attachment of the GBs to the
bubble surface reduces the available surface area, thereby
increasing the surface concentration of NPs at the interface.
The increased concentration of NPs at the interface leads to
an increase in NP-NP interactions, changing the nature of
Figure 4. Snapshot of particles on the bubble surface in the
bimodal system (40% of 66 μm +60% of 176 μm) at two
different independent runs
Figure 5. K value vs. surfactant concentration (x) in NPSCs (2.0 wt.% NP +× CMC).
Experiments are conducted with 3 gr of 66 µm GBs conditioned with 0.006 CMC
CTAB. The propeller speed was set to 400 rpm, and the bubble positioned at 5 mm
distance to the center
versa for high pH and anionic collectors. Furthermore, the
surface charge of the bubbles and particles is also affected
by pH, which can affect the interactions between particles
and bubbles (Albijanic et al. 2010).
The effect of 2.0 wt.% NP conditioned with 0.1, 0.3,
and 0.6 CMC CTAB on the dynamics of particle attach-
ment is studied, knowing that there might be a slight addi-
tional influence of the aforementioned parameters (pH,
ionic concentration, and NPs collector). The experiments
are conducted after a waiting time of 1000 s to allow NPs
(acting as ultrafine particles) to adsorb on the bubble surface.
As shown in Figure 5, the K value is significantly increased
by the presence of NPs, and the effect becomes more pro-
nounced as the hydrophobicity of the NPs increases.
The dynamics of particle attachment has been defined
so far by measuring the height or surface area of the cap
over time, with higher K values indicating better particle
collection and flotation performance. While this is true for
systems without NPs, it can be misleading for the systems
with NPs, as the packing density of the particles on the
bubble surface can be significantly reduced by the NPs,
resulting in higher K values that do not necessarily translate
into better flotation performance. This means that the sur-
face coverage can reach its maximum quite quickly, but the
packing density will be low. Therefore, the effect of NPs on
the packing density is investigated in the following.
Figure 6 illustratively shows and compares the packing
density of 66 µm GBs initially dispersed in water solution
and in NP solution (2.0 wt.% NP conditioned with 0.3
CMC CTAB). Again, a waiting time of about 1000 s is
given to ensure sufficient NPs adsorption on the bubble
surface. As it is evident, the presence of NPs at the inter-
face can strongly influence the distribution of the GBs on
the bubble surface. Here, the attachment of the GBs to the
bubble surface reduces the available surface area, thereby
increasing the surface concentration of NPs at the interface.
The increased concentration of NPs at the interface leads to
an increase in NP-NP interactions, changing the nature of
Figure 4. Snapshot of particles on the bubble surface in the
bimodal system (40% of 66 μm +60% of 176 μm) at two
different independent runs
Figure 5. K value vs. surfactant concentration (x) in NPSCs (2.0 wt.% NP +× CMC).
Experiments are conducted with 3 gr of 66 µm GBs conditioned with 0.006 CMC
CTAB. The propeller speed was set to 400 rpm, and the bubble positioned at 5 mm
distance to the center