3204 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
of efficient recycling methods becomes increasingly promi-
nent. In 2022, LFP batteries accounted for a 30% market
share, trailing behind NMC batteries, which held a 60%
share (International Energy Agency, 2023). Future projec-
tions by Wood Mackenzie (2022) indicate that LFP bat-
teries are set to surpass NMC variants in production by
2028. However, it’s important to note the disparity in
recycling values between these battery types. At the time of
Nichol’s (2023) study, the recycling value of LFP batteries
was significantly lower than that of NMC batteries -$9/
kWh for LFP compared to $25/kWh for NMC 111, based
on the prevailing metal prices. Nevertheless, EU regula-
tions mandate a minimum recycling rate of 70% by weight
for batteries, regardless of cathode chemistry (Regulation
(EU) 2023/1542.) Recycling LIBs is crucial for conserving
valuable resources and mitigating environmental hazards.
It enables the recovery of critical raw materials like lithium,
cobalt, and graphite, diminishing the need for fresh mining
operations and fostering resource sustainability. Improper
disposal of LIBs poses environmental threats through the
leakage of toxic chemicals and heavy metals, endangering
ecosystems and human health. Recycling addresses these
risks by ensuring safe and efficient battery waste manage-
ment (European Commission, 2019).
Extensive research has been dedicated to LIB recy-
cling, yet significant challenges persist due to the complex
chemistry and construction of these batteries. A particular
challenge involves the ‘black mass’, the fine fraction derived
from LIB comminution containing active anode and cath-
ode materials and impurities like aluminum and copper
foils. Most of the state-of-the-art recycling technologies
use black mass resulting from the mechanical pre-treat-
ment as a starting point for chemical processes for metal
recovery. Indeed, in industry, this black mass is usually
not further sorted and is directly fed to either established
or newly developed pyro- and/or hydrometallurgical pro-
cesses to extract metals from the cathode active materials,
although at the expense of graphite losses. In hydrometal-
lurgical processes, pre-removal of graphite from the black
mass can increase metal concentration in the feed, reduce
the volume of material for leaching and decrease con-
sumption of leaching reagents due to graphite’s porosity.
Thus, controlling feed composition to purification stages is
essential to minimize losses and operating costs, with pre-
concentration via froth flotation emerging as a promising
solution. Existing studies have explored froth flotation on
black mass containing NMC and LCO (Rinne et al., 2023
Shin et al., 2020 Vanderbruggen, 2022 Vanderbruggen et
al., 2021 Zhang et al., 2018), yet research on LFP black
mass remains limited (Riener et al., 2023). Furthermore,
the ultra-fine nature of LFP particles introduces additional
complexities in flotation processes. This study will employ
both pristine materials (LFP and spheroidized graphite)
and industrial black mass to examine the effects of an inno-
vative flotation reagent scheme, specifically a non-ionic
polyacrylamide flocculant. Variation of reagent dosages will
be tested to determine their impact on flotation efficiency.
Optimal parameters identified from pristine material flota-
tion will then be applied to industrial black mass. The find-
ings of this study will enhance the understanding of LFP
battery recycling, particularly in froth flotation beneficia-
tion of LFP black mass. By analyzing the behavior of novel
reagents in the flotation process, this research aims to refine
selective flotation techniques for LFP particles.
MATERIALS AND METHODS
Materials
The study investigated first pristine battery grade materi-
als of spheroidized natural graphite (Product No. 1112-
1, ProGraphite GmbH, Germany) and LiFePO4 (LFP)
(Product No. 25PO0127, MSE SuppliesTM, USA), SEM
images of these particles are shown in Figure 1. Model black
mass (MBM) with a 1:1 mass ratio of LFP and graphite
was also created to determine the interaction of particles
and reagents during flotation. Furthermore, an industrially
pyrolyzed black mass (IBM) provided by Accurec GmbH
(Germany) was also studied. The IBM is composed of
31.5% C, 66.7% LFP (calculated from %Fe), 0.45% Cu
and 0.8% Al.
For the flotation reagents, ESCAID 110 from
ExxonMobil, was utilized as a promoter for graphite sepa-
ration and methyl isobutyl carbinol (MIBC) from Alfa
Aesar functioned as a frothing agent. Additionally, poly-
acrylamide (PAM) from Sigma Aldrich, was incorporated
as a flocculant to aid in the aggregation of particles. For the
preparation of the flocculant, 1% stock solution of PAM
was made by dissolving 1 gram powder in 100 mL solution
in a background electrolyte of 10–3M KNO3 and stirring
overnight at 500 rpm. For experiments, the PAM stock
solution was diluted to 0.1%.
Bubble Loading
To determine the likelihood of battery materials attaching
to an air bubble and the effect of the different reagents on
their bubble loading, a bubble-particle attachment experi-
ment was conducted using an optical contour analysis
(OCA) system from DataPhysics Instruments (Figure 2).
To mimic conditions similar to those in a flotation cell, the
0.5 g particles were suspended in a cuvette with 100 ml
water and stirred at 600 rpm. Depending on the system
of efficient recycling methods becomes increasingly promi-
nent. In 2022, LFP batteries accounted for a 30% market
share, trailing behind NMC batteries, which held a 60%
share (International Energy Agency, 2023). Future projec-
tions by Wood Mackenzie (2022) indicate that LFP bat-
teries are set to surpass NMC variants in production by
2028. However, it’s important to note the disparity in
recycling values between these battery types. At the time of
Nichol’s (2023) study, the recycling value of LFP batteries
was significantly lower than that of NMC batteries -$9/
kWh for LFP compared to $25/kWh for NMC 111, based
on the prevailing metal prices. Nevertheless, EU regula-
tions mandate a minimum recycling rate of 70% by weight
for batteries, regardless of cathode chemistry (Regulation
(EU) 2023/1542.) Recycling LIBs is crucial for conserving
valuable resources and mitigating environmental hazards.
It enables the recovery of critical raw materials like lithium,
cobalt, and graphite, diminishing the need for fresh mining
operations and fostering resource sustainability. Improper
disposal of LIBs poses environmental threats through the
leakage of toxic chemicals and heavy metals, endangering
ecosystems and human health. Recycling addresses these
risks by ensuring safe and efficient battery waste manage-
ment (European Commission, 2019).
Extensive research has been dedicated to LIB recy-
cling, yet significant challenges persist due to the complex
chemistry and construction of these batteries. A particular
challenge involves the ‘black mass’, the fine fraction derived
from LIB comminution containing active anode and cath-
ode materials and impurities like aluminum and copper
foils. Most of the state-of-the-art recycling technologies
use black mass resulting from the mechanical pre-treat-
ment as a starting point for chemical processes for metal
recovery. Indeed, in industry, this black mass is usually
not further sorted and is directly fed to either established
or newly developed pyro- and/or hydrometallurgical pro-
cesses to extract metals from the cathode active materials,
although at the expense of graphite losses. In hydrometal-
lurgical processes, pre-removal of graphite from the black
mass can increase metal concentration in the feed, reduce
the volume of material for leaching and decrease con-
sumption of leaching reagents due to graphite’s porosity.
Thus, controlling feed composition to purification stages is
essential to minimize losses and operating costs, with pre-
concentration via froth flotation emerging as a promising
solution. Existing studies have explored froth flotation on
black mass containing NMC and LCO (Rinne et al., 2023
Shin et al., 2020 Vanderbruggen, 2022 Vanderbruggen et
al., 2021 Zhang et al., 2018), yet research on LFP black
mass remains limited (Riener et al., 2023). Furthermore,
the ultra-fine nature of LFP particles introduces additional
complexities in flotation processes. This study will employ
both pristine materials (LFP and spheroidized graphite)
and industrial black mass to examine the effects of an inno-
vative flotation reagent scheme, specifically a non-ionic
polyacrylamide flocculant. Variation of reagent dosages will
be tested to determine their impact on flotation efficiency.
Optimal parameters identified from pristine material flota-
tion will then be applied to industrial black mass. The find-
ings of this study will enhance the understanding of LFP
battery recycling, particularly in froth flotation beneficia-
tion of LFP black mass. By analyzing the behavior of novel
reagents in the flotation process, this research aims to refine
selective flotation techniques for LFP particles.
MATERIALS AND METHODS
Materials
The study investigated first pristine battery grade materi-
als of spheroidized natural graphite (Product No. 1112-
1, ProGraphite GmbH, Germany) and LiFePO4 (LFP)
(Product No. 25PO0127, MSE SuppliesTM, USA), SEM
images of these particles are shown in Figure 1. Model black
mass (MBM) with a 1:1 mass ratio of LFP and graphite
was also created to determine the interaction of particles
and reagents during flotation. Furthermore, an industrially
pyrolyzed black mass (IBM) provided by Accurec GmbH
(Germany) was also studied. The IBM is composed of
31.5% C, 66.7% LFP (calculated from %Fe), 0.45% Cu
and 0.8% Al.
For the flotation reagents, ESCAID 110 from
ExxonMobil, was utilized as a promoter for graphite sepa-
ration and methyl isobutyl carbinol (MIBC) from Alfa
Aesar functioned as a frothing agent. Additionally, poly-
acrylamide (PAM) from Sigma Aldrich, was incorporated
as a flocculant to aid in the aggregation of particles. For the
preparation of the flocculant, 1% stock solution of PAM
was made by dissolving 1 gram powder in 100 mL solution
in a background electrolyte of 10–3M KNO3 and stirring
overnight at 500 rpm. For experiments, the PAM stock
solution was diluted to 0.1%.
Bubble Loading
To determine the likelihood of battery materials attaching
to an air bubble and the effect of the different reagents on
their bubble loading, a bubble-particle attachment experi-
ment was conducted using an optical contour analysis
(OCA) system from DataPhysics Instruments (Figure 2).
To mimic conditions similar to those in a flotation cell, the
0.5 g particles were suspended in a cuvette with 100 ml
water and stirred at 600 rpm. Depending on the system