XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3207
RESULTS
Bubble Loading
The bubble-particle attachment experiments can be taken
as an indicator of the hydrophobicity of particles for the
tests in their pure form or after modification by chemical
reagents. The results of these experiments are summarized
in Table 1 and visualized in Figure 3.
In the case of graphite, even with no reagents, the
resulting loaded bubble area is 33.0±3.9%, indicating their
inherent hydrophobic nature. When graphite was treated
with MIBC, the bubble loading increased significantly to
90.5±4.8%. When conditioned with ESCAID, the bubble
was completely covered in graphite. Non-ionic hydro-
carbon collectors such as ESCAID have been proven to
increase the hydrophobicity of graphite (Chehreh Chelgani
et al., 2016 Zhou et al., 2020).
In the absence of reagents, LFP exhibited a low bubble
loading of 4.0±0.9%, potentially due to the presence of a
thin carbon layer on the LFP particles. The introduction of
MIBC alone did not significantly alter hydrophobicity, evi-
denced by a bubble loading of 4.1±0.7%, suggesting that
the wettability characteristics of the LFP particles remain
largely unaffected by MIBC. However, with the addition
of ESCAID, there was a notable increase in bubble load-
ing for LFP particles, reaching 16.2±2.3% which could
imply an interaction with ESCAID and hydrophobization
of thin carbon layer on the LFP particles. This enhance-
ment in hydrophobicity could be linked to the formation
of oil droplets by ESCAID, which spread over the particle
surfaces. Conversely, when both MIBC and ESCAID were
used, the bubble loading for LFP particles decreased to
10.9±3.0%. This reduction may be due to the adverse inter-
actions between ESCAID and MIBC, as documented in
prior studies. Naik et al. (2005) observed that kerosene can
emulsify MIBC through hydrophobic interactions, causing
the -OH groups in MIBC to orient towards the aqueous
phase. This interaction between MIBC and kerosene leads
to a diminished hydrophobic effect on the particle surfaces
and a concurrent decrease in the available MIBC for froth-
ing action.
When the LFP particles are conditioned with PAM,
the loading rate significantly reduced to 1.8±0.6%. This
reduction could be attributed to the impact of flocculation
on particle dynamics. Flocculation leads to the formation
of larger particle aggregates. Although an increase in par-
ticle size due to flocculation might theoretically enhance
collision efficiency with bubbles, the heavier aggregates
could paradoxically result in a lower bubble loading rate
due to increased detachment. This effect is further exempli-
fied when comparing treatments: the combination of PAM,
MIBC, and ESCAID yielded a lower loading value of
6.1±0.9%, in contrast to the 10.9±3.0% loading achieved
with just MIBC and ESCAID for LFP particles. This sug-
gests that the presence of PAM significantly influences the
loading efficiency, likely due to the altered physical proper-
ties of the particle aggregates.
For graphite particles treated with PAM, the bubble
loading was measured at 29.5±4.8%, which is slightly
lower compared to the loading of graphite particles with
no reagent. This reduction can be attributed to the action
of PAM, which, similar to its effect on LFP particles, likely
induces flocculation in graphite as well. The floccula-
tion process could lead to the formation of larger, heavier
aggregates of graphite particles, thus marginally reducing
their ability to adhere to bubbles. When PAM was used
in conjunction with MIBC and ESCAID, a similar trend
was observed. The bubble loading decreased from 100% to
85.0±3% for graphite particles conditioned with this com-
bination. This suggests that the presence of PAM in the
mixture affects the surface properties of the graphite par-
ticles, potentially altering their hydrophobicity or changing
the dynamics of bubble-particle interactions. The com-
bined effect of these reagents appears to modify the behav-
ior of graphite in the flotation process, resulting in a lower,
but still substantial, bubble loading efficiency.
Flotation Model Black Mass (MBM)
To understand the behavior of the active particles dur-
ing froth flotation and the influence of typical flotation
reagents, batch lab flotation tests were carried out on three
systems: pure graphite, LFP, and model black mass (MBM).
Flotation tests with ESCAID and MIBC on singular pris-
tine materials revealed a recovery of 5.1% for LFP and
93.3% for graphite in the overflow product, supporting the
bubble-loading experimental outcomes, presented in the
previous Section. Figure 4 presents the obtained results for
MBM flotation employing diverse reagent combinations
and dosages.
The flotation of MBM using only ESCAID and MIBC
achieved low selectivity, with a graphite recovery of only
45.5% and a grade of 38.9%C. With the introduction of
PAM into the reagent mix for MBM flotation, an improve-
ment in selectivity is observed. The addition of 50 g/t PAM
increases the recovery to 74.2% and significantly enhances
the grade to 82.3% C. This improvement can be attributed
to the flocculation effect of PAM, which induces the ultra-
fine LFP particles to form aggregates. Such agglomeration
increases the particle size, thereby reducing the likelihood
of their entrainment within the froth due to the increased
weight and size. Additionally, the flocculation reduces the
RESULTS
Bubble Loading
The bubble-particle attachment experiments can be taken
as an indicator of the hydrophobicity of particles for the
tests in their pure form or after modification by chemical
reagents. The results of these experiments are summarized
in Table 1 and visualized in Figure 3.
In the case of graphite, even with no reagents, the
resulting loaded bubble area is 33.0±3.9%, indicating their
inherent hydrophobic nature. When graphite was treated
with MIBC, the bubble loading increased significantly to
90.5±4.8%. When conditioned with ESCAID, the bubble
was completely covered in graphite. Non-ionic hydro-
carbon collectors such as ESCAID have been proven to
increase the hydrophobicity of graphite (Chehreh Chelgani
et al., 2016 Zhou et al., 2020).
In the absence of reagents, LFP exhibited a low bubble
loading of 4.0±0.9%, potentially due to the presence of a
thin carbon layer on the LFP particles. The introduction of
MIBC alone did not significantly alter hydrophobicity, evi-
denced by a bubble loading of 4.1±0.7%, suggesting that
the wettability characteristics of the LFP particles remain
largely unaffected by MIBC. However, with the addition
of ESCAID, there was a notable increase in bubble load-
ing for LFP particles, reaching 16.2±2.3% which could
imply an interaction with ESCAID and hydrophobization
of thin carbon layer on the LFP particles. This enhance-
ment in hydrophobicity could be linked to the formation
of oil droplets by ESCAID, which spread over the particle
surfaces. Conversely, when both MIBC and ESCAID were
used, the bubble loading for LFP particles decreased to
10.9±3.0%. This reduction may be due to the adverse inter-
actions between ESCAID and MIBC, as documented in
prior studies. Naik et al. (2005) observed that kerosene can
emulsify MIBC through hydrophobic interactions, causing
the -OH groups in MIBC to orient towards the aqueous
phase. This interaction between MIBC and kerosene leads
to a diminished hydrophobic effect on the particle surfaces
and a concurrent decrease in the available MIBC for froth-
ing action.
When the LFP particles are conditioned with PAM,
the loading rate significantly reduced to 1.8±0.6%. This
reduction could be attributed to the impact of flocculation
on particle dynamics. Flocculation leads to the formation
of larger particle aggregates. Although an increase in par-
ticle size due to flocculation might theoretically enhance
collision efficiency with bubbles, the heavier aggregates
could paradoxically result in a lower bubble loading rate
due to increased detachment. This effect is further exempli-
fied when comparing treatments: the combination of PAM,
MIBC, and ESCAID yielded a lower loading value of
6.1±0.9%, in contrast to the 10.9±3.0% loading achieved
with just MIBC and ESCAID for LFP particles. This sug-
gests that the presence of PAM significantly influences the
loading efficiency, likely due to the altered physical proper-
ties of the particle aggregates.
For graphite particles treated with PAM, the bubble
loading was measured at 29.5±4.8%, which is slightly
lower compared to the loading of graphite particles with
no reagent. This reduction can be attributed to the action
of PAM, which, similar to its effect on LFP particles, likely
induces flocculation in graphite as well. The floccula-
tion process could lead to the formation of larger, heavier
aggregates of graphite particles, thus marginally reducing
their ability to adhere to bubbles. When PAM was used
in conjunction with MIBC and ESCAID, a similar trend
was observed. The bubble loading decreased from 100% to
85.0±3% for graphite particles conditioned with this com-
bination. This suggests that the presence of PAM in the
mixture affects the surface properties of the graphite par-
ticles, potentially altering their hydrophobicity or changing
the dynamics of bubble-particle interactions. The com-
bined effect of these reagents appears to modify the behav-
ior of graphite in the flotation process, resulting in a lower,
but still substantial, bubble loading efficiency.
Flotation Model Black Mass (MBM)
To understand the behavior of the active particles dur-
ing froth flotation and the influence of typical flotation
reagents, batch lab flotation tests were carried out on three
systems: pure graphite, LFP, and model black mass (MBM).
Flotation tests with ESCAID and MIBC on singular pris-
tine materials revealed a recovery of 5.1% for LFP and
93.3% for graphite in the overflow product, supporting the
bubble-loading experimental outcomes, presented in the
previous Section. Figure 4 presents the obtained results for
MBM flotation employing diverse reagent combinations
and dosages.
The flotation of MBM using only ESCAID and MIBC
achieved low selectivity, with a graphite recovery of only
45.5% and a grade of 38.9%C. With the introduction of
PAM into the reagent mix for MBM flotation, an improve-
ment in selectivity is observed. The addition of 50 g/t PAM
increases the recovery to 74.2% and significantly enhances
the grade to 82.3% C. This improvement can be attributed
to the flocculation effect of PAM, which induces the ultra-
fine LFP particles to form aggregates. Such agglomeration
increases the particle size, thereby reducing the likelihood
of their entrainment within the froth due to the increased
weight and size. Additionally, the flocculation reduces the