3206 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
As detailed in Vanderbruggen et al. (2021), the bubble
loading was quantitatively estimated with equation 1, after
measuring different areas with the aid of ImageJ 1.8.0 pro-
cessing software:
%A A
A
Bubble Loading,
b c
P =-(1)
where Ap is the area loaded with particles, Ab is the total
bubble area, and Ac is the area of the bubble where particles
cannot be attached due to physical barriers, as shown in the
Figure 2. To ensure accuracy, a minimum of six measure-
ments were taken for each sample. It is important to note
that in these experiments, the analysis is done in 2D image
and focus was exclusively on monitoring the efficiency of
particle-bubble collection.
Froth Flotation
The separation of graphite and LFP particles via froth flota-
tion was first investigated using a pristine material of sphe-
riodized natural graphite and LFP, followed by the model
black mass (MBM), and finally with an industrially pyro-
lyzed black mass (IBM) from Accurec GmbH. The flota-
tion tests were performed with a mechanically stirred GTK
Labcell at an impeller speed of 1000 rpm, air flowrate of 5
L/min, and a pulp density of 7 weight %solids. One (1) L
capacity cell was used for MBM while 2 L capacity cell was
used for IBM. MIBC and ESCAID were used in fixed dos-
ages of 150 g/t and 250 g/t, respectively. Additionally, PAM
was used in various dosage (50, 100, and 150 g/t) as a floc-
culant to aid in the aggregation of fine particles of LFP. For
the experiment with attrition pre-treatment, a dispersing
instrument (T25, IKA Ultra-Turrax) was used at the agita-
tion speed of 16,000 rpm and duration of 5 minutes. After
each flotation experiment, the mass of collected froth was
measured before and after drying in an oven under natural
convection for 12 h at 45 °C to determine mass and water
pull. Finally, representative samples of the flotation prod-
ucts were the carbon content was analyzed using a ELTRA
CS 580 Carbon and Sulfur analyzer at TU Bergakademie
Freiberg, Institute of Non-Ferrous Metallurgy and High
Purity Materials (Freiberg, Germany).
Table 1. Loaded bubble area of LFP and graphite particles and model and industrial black mass using different reagent
combinations
No reagent MIBC ESCAID
ESCAID
+MIBC PAM
PAM
+ESCAID+MIBC
LFP 4.0±0.9 4.1±0.7 16.2±2.3 10.9±3.0 1.8±0.6 6.1±0.9
Graphite 33.0±3.9 90.5±4.8 100 100 29.5±4.8 85.0±3
MBM 7.1±2.6 7.5±1.2 22.3±4.3 34.3±3.4 14.3±2.0 33.1±7.1
IBM 5.1±0.6 5.9±1.3 80.8±8.7 93.5±5.5 4.9±1.0 75.2±9.9
Figure 3. The area of air bubble loaded with LFP or graphite particles using various reagents
As detailed in Vanderbruggen et al. (2021), the bubble
loading was quantitatively estimated with equation 1, after
measuring different areas with the aid of ImageJ 1.8.0 pro-
cessing software:
%A A
A
Bubble Loading,
b c
P =-(1)
where Ap is the area loaded with particles, Ab is the total
bubble area, and Ac is the area of the bubble where particles
cannot be attached due to physical barriers, as shown in the
Figure 2. To ensure accuracy, a minimum of six measure-
ments were taken for each sample. It is important to note
that in these experiments, the analysis is done in 2D image
and focus was exclusively on monitoring the efficiency of
particle-bubble collection.
Froth Flotation
The separation of graphite and LFP particles via froth flota-
tion was first investigated using a pristine material of sphe-
riodized natural graphite and LFP, followed by the model
black mass (MBM), and finally with an industrially pyro-
lyzed black mass (IBM) from Accurec GmbH. The flota-
tion tests were performed with a mechanically stirred GTK
Labcell at an impeller speed of 1000 rpm, air flowrate of 5
L/min, and a pulp density of 7 weight %solids. One (1) L
capacity cell was used for MBM while 2 L capacity cell was
used for IBM. MIBC and ESCAID were used in fixed dos-
ages of 150 g/t and 250 g/t, respectively. Additionally, PAM
was used in various dosage (50, 100, and 150 g/t) as a floc-
culant to aid in the aggregation of fine particles of LFP. For
the experiment with attrition pre-treatment, a dispersing
instrument (T25, IKA Ultra-Turrax) was used at the agita-
tion speed of 16,000 rpm and duration of 5 minutes. After
each flotation experiment, the mass of collected froth was
measured before and after drying in an oven under natural
convection for 12 h at 45 °C to determine mass and water
pull. Finally, representative samples of the flotation prod-
ucts were the carbon content was analyzed using a ELTRA
CS 580 Carbon and Sulfur analyzer at TU Bergakademie
Freiberg, Institute of Non-Ferrous Metallurgy and High
Purity Materials (Freiberg, Germany).
Table 1. Loaded bubble area of LFP and graphite particles and model and industrial black mass using different reagent
combinations
No reagent MIBC ESCAID
ESCAID
+MIBC PAM
PAM
+ESCAID+MIBC
LFP 4.0±0.9 4.1±0.7 16.2±2.3 10.9±3.0 1.8±0.6 6.1±0.9
Graphite 33.0±3.9 90.5±4.8 100 100 29.5±4.8 85.0±3
MBM 7.1±2.6 7.5±1.2 22.3±4.3 34.3±3.4 14.3±2.0 33.1±7.1
IBM 5.1±0.6 5.9±1.3 80.8±8.7 93.5±5.5 4.9±1.0 75.2±9.9
Figure 3. The area of air bubble loaded with LFP or graphite particles using various reagents