XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3195
absence and presence of plasma treatment were compared.
Effects of plasma treatment on flotation kinetics of elec-
trode materials were investigated. Finally, we discussed the
enhancement mechanisms of flotation selectivity of elec-
trode materials by plasma treatment using XRD, FTIR
and XPS analyses. The study proposed a green and mild
alternative technology based on green plasma modifications
for the selective flotation separation of anode and cathode
materials of spent LIBs.
EXPERIMENTAL
Materials
Spent ternary 18560 LIBs used in cars were collected
from battery recycling stations located in Xuzhou, China.
Spent LIBs were discharged and manually dismantled.
After that, the graphite-covered anode and ternary-covered
cathodes were cut into pieces with a size of 1 cm × 1 cm
using scissors, respectively. The liberation of anode and
cathode materials from metal foils were performed using
an ultrasound-mechanical stirrer with an ultrasound power
of 182 W, mechanical impeller speed of 200 r/min, and
treatment time of 3 minutes. The details of the discharge,
dismantling, and peeling-off processes can be found in our
previous work (Ren et al., 2023). The liberated anode and
cathode materials were collected and screened by a sieve
with an aperture size of 74 μm. Unless otherwise specified,
these samples with a particle size of –74 μm were used in all
tests. Kerosene and sec-octyl alcohol were used as the collec-
tor and frother, respectively.
Plasma Treatment
Plasma treatment tests of anode and cathode materials were
performed using a O2 Plasma Cleaner (PLAUX-PR40L,
Kunshan Plaux Electronic Technology Co., Ltd., Kunshan,
China). Different experimental levels of plasma powers (50,
100, and 150 W), gas flowrates (100, 200, and 300 mL/
min), and treatment duration (1, 3, and 5 min(s)) were
used for the plasma modification. The contact angles of
electrode materials after plasma treatment were collected
to illustrate Violin plots. For the original contact angles
of anode and cathode materials, repeated experiments are
used to obtain the required data for Violin plots.
Contact Angle Measurement
Anode and cathode samples of approximately 1 g were
pressed for 50 s using the pressure of 15 MPa into thin
circular plates, respectively. A Powereach JC2000D1 con-
tact angle measurement apparatus (Shanghai Zhongchen
Digital Technic Apparatus Co., Ltd., Shanghai, China)
was used for water contact angle measurements. The
measurement procedure has been described in the literature
(Gao et al., 2023).
XRD, XPS and FTIR Measurements
XRD patterns were collected using a D/MAX-2500 pc pow-
der diffractometer equipped with Cu-Kα (λ= 1.54 Å) radia-
tion which was generated at 40 kV and 40 mA in China
University of Mining and Technology. The XPS measure-
ments of the samples with and without plasma treatment
was operated with a 30-mA filament current using an Al
Kα (hv =1486.6 eV) radiation source by XPS (ESCALAB
250Xi, Thermo Fischer). XPSPEAK software was used to
perform peak fitting on the raw data. The FTIR measure-
ments were carried out using the FTIR spectrometer of
Vertex 80v (Bruker Inc., Germany) with KBr method. All
FTIR tests were conducted with a resolution of 4 cm–1 and
a range of 400–4000 cm–1. The details of XRD, XPS and
FTIR measurements can be found in the literatures (Bu et
al., 2017 Chen et al., 2022).
Micro-Flotation Test
The micro-flotations tests were carried out by a flotation cell
with a model name of XFG-5 (Nanchang Jianfeng Mining
Machinery Manufacturing Co. Ld., Nanchang, China).
The slurry (40 mL) containing 3 g solid particles was condi-
tioned for one minute. After that, the required amounts of
collector and frother were added and conditioned for 3 and
1 minute(s), respectively. Based on the literature (Verdugo
et al., 2022), the dosages of collector and frother were set
as 350 and 100 g/t, respectively. During the flotation pro-
cess, the impeller speed and air flowrate were set to 1,000
rpm and 40 mL/min. Details of flotation procedures can be
found in the literature (Zhou et al., 2022).
The froth products were recovered with 4-time inter-
vals (0–0.5, 0.5–1, 1–2, and 2–4 minute(s)) for a total flo-
tation duration of 4 minutes. All flotation products were
collected and dried in a dryer (at 100 °C for 120 minutes)
to determine their weight, and thus mass recoveries and
kinetics. The relative rate constant (selectivity index) is a
useful tool for comparative evaluations of various operat-
ing parameters affecting graphite flotation (Zhou et al.,
2020), electrode materials of LIBs (Verdugo et al., 2022),
malachite ore (Marion et al., 2017), and coals (Vapur et al.,
2010). The selectivity index (SI) was employed to evaluate
the flotation selectivity between anode and cathode materi-
als. SI is defined as the ratio of the modified rate constant
(km) between mineral I and mineral II (Eq. 1) (Xu, 1998).
km,
km,
k R3,
k R3,
SI
cathode
anode
cathode cathode
anode anode
$
$
==(1)
absence and presence of plasma treatment were compared.
Effects of plasma treatment on flotation kinetics of elec-
trode materials were investigated. Finally, we discussed the
enhancement mechanisms of flotation selectivity of elec-
trode materials by plasma treatment using XRD, FTIR
and XPS analyses. The study proposed a green and mild
alternative technology based on green plasma modifications
for the selective flotation separation of anode and cathode
materials of spent LIBs.
EXPERIMENTAL
Materials
Spent ternary 18560 LIBs used in cars were collected
from battery recycling stations located in Xuzhou, China.
Spent LIBs were discharged and manually dismantled.
After that, the graphite-covered anode and ternary-covered
cathodes were cut into pieces with a size of 1 cm × 1 cm
using scissors, respectively. The liberation of anode and
cathode materials from metal foils were performed using
an ultrasound-mechanical stirrer with an ultrasound power
of 182 W, mechanical impeller speed of 200 r/min, and
treatment time of 3 minutes. The details of the discharge,
dismantling, and peeling-off processes can be found in our
previous work (Ren et al., 2023). The liberated anode and
cathode materials were collected and screened by a sieve
with an aperture size of 74 μm. Unless otherwise specified,
these samples with a particle size of –74 μm were used in all
tests. Kerosene and sec-octyl alcohol were used as the collec-
tor and frother, respectively.
Plasma Treatment
Plasma treatment tests of anode and cathode materials were
performed using a O2 Plasma Cleaner (PLAUX-PR40L,
Kunshan Plaux Electronic Technology Co., Ltd., Kunshan,
China). Different experimental levels of plasma powers (50,
100, and 150 W), gas flowrates (100, 200, and 300 mL/
min), and treatment duration (1, 3, and 5 min(s)) were
used for the plasma modification. The contact angles of
electrode materials after plasma treatment were collected
to illustrate Violin plots. For the original contact angles
of anode and cathode materials, repeated experiments are
used to obtain the required data for Violin plots.
Contact Angle Measurement
Anode and cathode samples of approximately 1 g were
pressed for 50 s using the pressure of 15 MPa into thin
circular plates, respectively. A Powereach JC2000D1 con-
tact angle measurement apparatus (Shanghai Zhongchen
Digital Technic Apparatus Co., Ltd., Shanghai, China)
was used for water contact angle measurements. The
measurement procedure has been described in the literature
(Gao et al., 2023).
XRD, XPS and FTIR Measurements
XRD patterns were collected using a D/MAX-2500 pc pow-
der diffractometer equipped with Cu-Kα (λ= 1.54 Å) radia-
tion which was generated at 40 kV and 40 mA in China
University of Mining and Technology. The XPS measure-
ments of the samples with and without plasma treatment
was operated with a 30-mA filament current using an Al
Kα (hv =1486.6 eV) radiation source by XPS (ESCALAB
250Xi, Thermo Fischer). XPSPEAK software was used to
perform peak fitting on the raw data. The FTIR measure-
ments were carried out using the FTIR spectrometer of
Vertex 80v (Bruker Inc., Germany) with KBr method. All
FTIR tests were conducted with a resolution of 4 cm–1 and
a range of 400–4000 cm–1. The details of XRD, XPS and
FTIR measurements can be found in the literatures (Bu et
al., 2017 Chen et al., 2022).
Micro-Flotation Test
The micro-flotations tests were carried out by a flotation cell
with a model name of XFG-5 (Nanchang Jianfeng Mining
Machinery Manufacturing Co. Ld., Nanchang, China).
The slurry (40 mL) containing 3 g solid particles was condi-
tioned for one minute. After that, the required amounts of
collector and frother were added and conditioned for 3 and
1 minute(s), respectively. Based on the literature (Verdugo
et al., 2022), the dosages of collector and frother were set
as 350 and 100 g/t, respectively. During the flotation pro-
cess, the impeller speed and air flowrate were set to 1,000
rpm and 40 mL/min. Details of flotation procedures can be
found in the literature (Zhou et al., 2022).
The froth products were recovered with 4-time inter-
vals (0–0.5, 0.5–1, 1–2, and 2–4 minute(s)) for a total flo-
tation duration of 4 minutes. All flotation products were
collected and dried in a dryer (at 100 °C for 120 minutes)
to determine their weight, and thus mass recoveries and
kinetics. The relative rate constant (selectivity index) is a
useful tool for comparative evaluations of various operat-
ing parameters affecting graphite flotation (Zhou et al.,
2020), electrode materials of LIBs (Verdugo et al., 2022),
malachite ore (Marion et al., 2017), and coals (Vapur et al.,
2010). The selectivity index (SI) was employed to evaluate
the flotation selectivity between anode and cathode materi-
als. SI is defined as the ratio of the modified rate constant
(km) between mineral I and mineral II (Eq. 1) (Xu, 1998).
km,
km,
k R3,
k R3,
SI
cathode
anode
cathode cathode
anode anode
$
$
==(1)