3236 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
other technologies could pave the way to new process flow-
sheets. Among these technologies, electrodialysis could be
an interesting alternative since this technology is mature
and can be very efficient to separate ions without adding
huge amounts of reagent. Therefore, this paper aims at
investigating how electrodialysis could be implemented in
hydrometallurgical flowsheets to recover metals from black
mass of spent lithium-ion batteries.
EXPERIMENTAL
Reagents
The aqueous solutions in the anodic and cathodic compart-
ments, the aqueous solutions for solvent extraction (SX)
experiments and the synthetic leach solution were prepared
by dissolving appropriate amounts of reagents into deion-
ized water (resistivity =18 Ω·cm), i.e., Li2SO4 (Aldrich,
purity ≥98.5%), CoSO4.7H2O (Aldrich, purity ≥99%),
NiSO4.6H2O (Aldrich, purity ≥ 98%), MnSO4.H2O
(Aldrich, purity ≥99%). The solution of 0.1 mol L−1 sulfu-
ric acid was prepared by diluting an appropriate amount of
concentrated H2SO4 (Aldrich, purity =97%) in deionized
water (resistivity =18 MΩ·cm). The composition of the
synthetic solution was representative of leach solutions of
NMC111 cathodic materials, i.e., 2.60 g L−1 lithium(I),
7.88 g L−1 cobalt(II), 8.01 g L−1 nickel(II), 4.40 g L−1
manganese(II) and 51.45 g L−1 sulfate [1]. The pH of the
aqueous solutions containing the metal salts was adjusted
to pH =2.83 by adding 0.1 mol L−1 sulfuric acid to find the
best compromise between the faradic yield and the lithium
extraction efficiency.
The organic phases for the liquid-liquid experiments
were prepared by diluting the appropriate amounts of
Cyanex ®272 (bis-(2,4,4-trimethylpentyl) phosphinic
acid, purity=90%) and DEHPA (bis(2-ethylhexyl) phos-
phoric acid, purity=95%) provided by Solvay in kerosene
(Aldrich).
Electrodialysis setup
The ED setup displayed in Figure 1 was composed of a
DC power (Microlab, Parsippany, New Jersey, USA), a
2L-anode solution reservoir, a 2L-dilute reservoir fed by
the leach solution, a 2L-concentrate reservoir, a 2L-cathode
solution reservoir and four peristaltic pumps (Masterflex
L/S model 77250-62, assembled by Parmer Instrument
Company, USA).
The flow rate was fixed at 100 mL min−1 for all experi-
ments. Neosepta ® AMX (Astom Company, Tokyo Japan)
was used as the anionic exchange membrane (AEM) and
Neosepta ® monovalent-selective membrane (provided
by Eurodia Industrie, France) was used as the cationic
exchange membrane (CEM). Prior to experiments, the cat-
ionic exchange membranes were immersed into an aque-
ous solution containing 0.1 mol L−1 Li2SO4 and deionized
water for 24 h whereas the anionic exchange membranes
were immersed in deionized water for 24 h.
Solvent Extraction
Solvent extraction experiments were performed by con-
tacting 10 mL of the aqueous phase with 10 mL of the
organic phase in a centrifuge tube (50 mL). The two non-
miscible phases were mixed during 15 minutes at room
temperature and 200 rpm with a mechanical stirring appa-
ratus (Gherardt Laboshake) equipped thermostat, so that
the equilibrium was reached. Samples were centrifuged at
3000 rpm for 2 min by means of a Sigma 316L Compact
Benchtop Centrifuge in order to separate the organic and
the aqueous phases. Before analysing the metal concentra-
tions in the aqueous phases, the aqueous solutions were fil-
tered to remove traces of organic phase with a hydrophilic
filter (Minisart NML 16555K, cellulose acetate, 0.45 µm,
d=28 mm, provider:VWR).
Elemental analyses
Elemental analyses were performed using a microwave
plasma-atomic emission spectrometer (MP-AES 4210,
Agilent). The wavelengths used for elemental analyses of
lithium, nickel, cobalt and manganese were 497.175 nm,
361.939 nm, 350.631 nm and 294.920 nm, respectively.
The samples were diluted in 2% (vol.) nitric acid prepared
from a concentrated solution (HNO3, 95%, Aldrich)
by dilution in deionized water (resistivity 18 MΩ·cm).
Standards for MP analyses were prepared by diluting
Figure 1. Experimental setup for electrodialysis experiments
other technologies could pave the way to new process flow-
sheets. Among these technologies, electrodialysis could be
an interesting alternative since this technology is mature
and can be very efficient to separate ions without adding
huge amounts of reagent. Therefore, this paper aims at
investigating how electrodialysis could be implemented in
hydrometallurgical flowsheets to recover metals from black
mass of spent lithium-ion batteries.
EXPERIMENTAL
Reagents
The aqueous solutions in the anodic and cathodic compart-
ments, the aqueous solutions for solvent extraction (SX)
experiments and the synthetic leach solution were prepared
by dissolving appropriate amounts of reagents into deion-
ized water (resistivity =18 Ω·cm), i.e., Li2SO4 (Aldrich,
purity ≥98.5%), CoSO4.7H2O (Aldrich, purity ≥99%),
NiSO4.6H2O (Aldrich, purity ≥ 98%), MnSO4.H2O
(Aldrich, purity ≥99%). The solution of 0.1 mol L−1 sulfu-
ric acid was prepared by diluting an appropriate amount of
concentrated H2SO4 (Aldrich, purity =97%) in deionized
water (resistivity =18 MΩ·cm). The composition of the
synthetic solution was representative of leach solutions of
NMC111 cathodic materials, i.e., 2.60 g L−1 lithium(I),
7.88 g L−1 cobalt(II), 8.01 g L−1 nickel(II), 4.40 g L−1
manganese(II) and 51.45 g L−1 sulfate [1]. The pH of the
aqueous solutions containing the metal salts was adjusted
to pH =2.83 by adding 0.1 mol L−1 sulfuric acid to find the
best compromise between the faradic yield and the lithium
extraction efficiency.
The organic phases for the liquid-liquid experiments
were prepared by diluting the appropriate amounts of
Cyanex ®272 (bis-(2,4,4-trimethylpentyl) phosphinic
acid, purity=90%) and DEHPA (bis(2-ethylhexyl) phos-
phoric acid, purity=95%) provided by Solvay in kerosene
(Aldrich).
Electrodialysis setup
The ED setup displayed in Figure 1 was composed of a
DC power (Microlab, Parsippany, New Jersey, USA), a
2L-anode solution reservoir, a 2L-dilute reservoir fed by
the leach solution, a 2L-concentrate reservoir, a 2L-cathode
solution reservoir and four peristaltic pumps (Masterflex
L/S model 77250-62, assembled by Parmer Instrument
Company, USA).
The flow rate was fixed at 100 mL min−1 for all experi-
ments. Neosepta ® AMX (Astom Company, Tokyo Japan)
was used as the anionic exchange membrane (AEM) and
Neosepta ® monovalent-selective membrane (provided
by Eurodia Industrie, France) was used as the cationic
exchange membrane (CEM). Prior to experiments, the cat-
ionic exchange membranes were immersed into an aque-
ous solution containing 0.1 mol L−1 Li2SO4 and deionized
water for 24 h whereas the anionic exchange membranes
were immersed in deionized water for 24 h.
Solvent Extraction
Solvent extraction experiments were performed by con-
tacting 10 mL of the aqueous phase with 10 mL of the
organic phase in a centrifuge tube (50 mL). The two non-
miscible phases were mixed during 15 minutes at room
temperature and 200 rpm with a mechanical stirring appa-
ratus (Gherardt Laboshake) equipped thermostat, so that
the equilibrium was reached. Samples were centrifuged at
3000 rpm for 2 min by means of a Sigma 316L Compact
Benchtop Centrifuge in order to separate the organic and
the aqueous phases. Before analysing the metal concentra-
tions in the aqueous phases, the aqueous solutions were fil-
tered to remove traces of organic phase with a hydrophilic
filter (Minisart NML 16555K, cellulose acetate, 0.45 µm,
d=28 mm, provider:VWR).
Elemental analyses
Elemental analyses were performed using a microwave
plasma-atomic emission spectrometer (MP-AES 4210,
Agilent). The wavelengths used for elemental analyses of
lithium, nickel, cobalt and manganese were 497.175 nm,
361.939 nm, 350.631 nm and 294.920 nm, respectively.
The samples were diluted in 2% (vol.) nitric acid prepared
from a concentrated solution (HNO3, 95%, Aldrich)
by dilution in deionized water (resistivity 18 MΩ·cm).
Standards for MP analyses were prepared by diluting
Figure 1. Experimental setup for electrodialysis experiments