XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3189
NMC materials and 27.53% by weight of graphite. Table 3
shows a summary of the experimental result. After the
rougher stage, the concentrate product consisted of 90.79%
by weight of NMC and 9.03% by weight of graphite, while
the tailing product consisted of 26.00% by weight of NMC
and 73.62% by weight of graphite. The separation efficiency
reached 67%. This separation efficiency was comparable to
that obtained with a mixture of pristine anode and cathode
materials as the black mass feed materials. After one cleaner
stage, the grade of NMC in the concentrate product was
increased to 99.2%. The overflow product from rougher
stage was fed to the scavenger cycle to recover the remain-
ing NMC. After one scavenger cycle, the grade of NMC in
the overflow product decreased from 26.0% to 18.6% with
over 54% of them reclaimed. The overall recovery of NMC
particles in the final concentrate product exceeded 94%,
assuming all intermedia products were recycled and refed
into the rougher cycles.
To understand the loss of NMC after the scavenger
cycle, both SEM imaging and EDX mapping analysis
with the tailing product was conducted and performed. As
shown in Figure 6, ultrafine cathode active particles were
found in the overflow product. The loss of individual cath-
ode active materials (NMC) was attributed to the ultrafine
sizes of these particles. These ultrafine cathode particles
cannot be retained in the concentrate bed and carried out
into overflow product. The underflow product consisted of
uniform large-sized cathode active particles.
CONCLUSION AND SUMMARY
In this study, a novel recycling process has been devel-
oped to process black mass recycled from both new and
spent Li-ion batteries with two size fractions (–104µm and
–45µm). Result showed that the gravity separation process
can be used to concentrate cathode active materials from
the black mass feed materials. Compared to the black mass
obtained from new Li-ion batteries, the separation perfor-
mance was improved with spent Li-ion batteries, which
was primarily attributed to the weakened binding between
Table 3. Separation results of three products using a standard rougher-scavenger-cleaner process circuit
Product Weight (%)
Grade
Distribution,
without Recycling Middling
Distribution,
with recycling Middling
%NMC %Graphite NMC Graphite NMC Graphite
Cleaner—
Concentrate
53.58% 99.18% 0.70% 73.83% 1.34% 93.86% 2.45%
Scavenger—Tail 18.37% 18.58% 81.00% 4.74% 59.74% 6.04% 97.55%
Middling 28.05% 54.98% 44.70% 21.43% 38.92% --
Figure 6. a) SEM and EDX mapping images of the overflow product, b) SEM and EDX mapping images of the underflow
product. c) particle size distribution of underflow and overflow product, in comparison with anode and cathode materials after
a thermal pyrolysis process
NMC materials and 27.53% by weight of graphite. Table 3
shows a summary of the experimental result. After the
rougher stage, the concentrate product consisted of 90.79%
by weight of NMC and 9.03% by weight of graphite, while
the tailing product consisted of 26.00% by weight of NMC
and 73.62% by weight of graphite. The separation efficiency
reached 67%. This separation efficiency was comparable to
that obtained with a mixture of pristine anode and cathode
materials as the black mass feed materials. After one cleaner
stage, the grade of NMC in the concentrate product was
increased to 99.2%. The overflow product from rougher
stage was fed to the scavenger cycle to recover the remain-
ing NMC. After one scavenger cycle, the grade of NMC in
the overflow product decreased from 26.0% to 18.6% with
over 54% of them reclaimed. The overall recovery of NMC
particles in the final concentrate product exceeded 94%,
assuming all intermedia products were recycled and refed
into the rougher cycles.
To understand the loss of NMC after the scavenger
cycle, both SEM imaging and EDX mapping analysis
with the tailing product was conducted and performed. As
shown in Figure 6, ultrafine cathode active particles were
found in the overflow product. The loss of individual cath-
ode active materials (NMC) was attributed to the ultrafine
sizes of these particles. These ultrafine cathode particles
cannot be retained in the concentrate bed and carried out
into overflow product. The underflow product consisted of
uniform large-sized cathode active particles.
CONCLUSION AND SUMMARY
In this study, a novel recycling process has been devel-
oped to process black mass recycled from both new and
spent Li-ion batteries with two size fractions (–104µm and
–45µm). Result showed that the gravity separation process
can be used to concentrate cathode active materials from
the black mass feed materials. Compared to the black mass
obtained from new Li-ion batteries, the separation perfor-
mance was improved with spent Li-ion batteries, which
was primarily attributed to the weakened binding between
Table 3. Separation results of three products using a standard rougher-scavenger-cleaner process circuit
Product Weight (%)
Grade
Distribution,
without Recycling Middling
Distribution,
with recycling Middling
%NMC %Graphite NMC Graphite NMC Graphite
Cleaner—
Concentrate
53.58% 99.18% 0.70% 73.83% 1.34% 93.86% 2.45%
Scavenger—Tail 18.37% 18.58% 81.00% 4.74% 59.74% 6.04% 97.55%
Middling 28.05% 54.98% 44.70% 21.43% 38.92% --
Figure 6. a) SEM and EDX mapping images of the overflow product, b) SEM and EDX mapping images of the underflow
product. c) particle size distribution of underflow and overflow product, in comparison with anode and cathode materials after
a thermal pyrolysis process