3211
Spent Lithium-Ion Battery Black Mass Variability on
Flotation Response
Ben Yu, Martin Couillard, Gilles Robertson, Xin Jiang, and Andrzej Nicalek
National Research Council (Canada) (NRC)
ABSTRACT: In recent years, there is an increase focus on lithium-ion batteries recycling primarily on
recovering cathodic metals such as nickel, cobalt, manganese, and lithium where the economic value lies. As
Environmental, Social and Governance (ESG) plays a bigger role requiring more components in a battery
to be recycled, a new focus is placed on recovering graphite. Publication to date has focused on the various
pre-treatment prior to flotation for separation or the battery chemistry type to flotation response. Currently,
most commercial black mass, unless from scrap electrode, tends to be a mix of various battery type in varying
chemical composition and binders used. This paper presents the flotation response after thermal pre-treatment
of three black mass obtained from commercial recyclers having different chemical compositions.
Keywords: lithium-ion battery recycling, graphite, characterization, flotation
INTRODUCTION
In most cases, graphite is not commercially recycled in lith-
ium-ion battery recycling due to its lower economic value
but can be recycled without significantly altering current
commercial or developing processes. Graphite can be recov-
ered from black mass prior to leaching the cathodic metals
or after leaching where graphite deports to the leach resi-
due. Recovering graphite after leaching may result in dam-
ages to the graphite lattice structure requiring subsequent
treatment such as coating to repair. This makes recovering
graphite prior to leaching a preference. Literature is still
limited and focused mainly on binder removal and flota-
tion to recover graphite. Babanejad et al. (2022) studied
the thermal behavior of lithium-cobalt oxides black mass
using thermogravimetric/differential thermal analysis and
found three distinct regions in the temperature-mass pro-
files. Initial mass loss was found at 200–300°C, followed by
an exothermic reaction at 600°C and the main mass loss at
900°C. The authors assigned the initial mass loss to organic
compound decomposition. The second mass loss was to the
LiCoO2 transformation to simpler components while the
main mass loss was gasification of carbon or Li2O volatil-
ization. The authors illustrated that binder removal is pos-
sible with thermal treatment. Other pre-treatments such
as Fenton oxidation and pyrolysis prior to flotation were
investigated by He et al. (2017), Wang et al. (2018), and
Zhang et al. (2018). Mass pull of approximately 30% to the
graphite concentrate was possible. True flotation concen-
trate grade, recovery, and losses were not provided. Salces et
al. (2022), using a pyrolyzed black mass at 500°C, achieved
85% graphite recovery with 20% Ni-Mn-Co losses in
the graphite rougher concentrate. The authors noted that
Ni-Mn-Co losses were reduced by over 20% with attrition
prior to flotation.
Spent Lithium-Ion Battery Black Mass Variability on
Flotation Response
Ben Yu, Martin Couillard, Gilles Robertson, Xin Jiang, and Andrzej Nicalek
National Research Council (Canada) (NRC)
ABSTRACT: In recent years, there is an increase focus on lithium-ion batteries recycling primarily on
recovering cathodic metals such as nickel, cobalt, manganese, and lithium where the economic value lies. As
Environmental, Social and Governance (ESG) plays a bigger role requiring more components in a battery
to be recycled, a new focus is placed on recovering graphite. Publication to date has focused on the various
pre-treatment prior to flotation for separation or the battery chemistry type to flotation response. Currently,
most commercial black mass, unless from scrap electrode, tends to be a mix of various battery type in varying
chemical composition and binders used. This paper presents the flotation response after thermal pre-treatment
of three black mass obtained from commercial recyclers having different chemical compositions.
Keywords: lithium-ion battery recycling, graphite, characterization, flotation
INTRODUCTION
In most cases, graphite is not commercially recycled in lith-
ium-ion battery recycling due to its lower economic value
but can be recycled without significantly altering current
commercial or developing processes. Graphite can be recov-
ered from black mass prior to leaching the cathodic metals
or after leaching where graphite deports to the leach resi-
due. Recovering graphite after leaching may result in dam-
ages to the graphite lattice structure requiring subsequent
treatment such as coating to repair. This makes recovering
graphite prior to leaching a preference. Literature is still
limited and focused mainly on binder removal and flota-
tion to recover graphite. Babanejad et al. (2022) studied
the thermal behavior of lithium-cobalt oxides black mass
using thermogravimetric/differential thermal analysis and
found three distinct regions in the temperature-mass pro-
files. Initial mass loss was found at 200–300°C, followed by
an exothermic reaction at 600°C and the main mass loss at
900°C. The authors assigned the initial mass loss to organic
compound decomposition. The second mass loss was to the
LiCoO2 transformation to simpler components while the
main mass loss was gasification of carbon or Li2O volatil-
ization. The authors illustrated that binder removal is pos-
sible with thermal treatment. Other pre-treatments such
as Fenton oxidation and pyrolysis prior to flotation were
investigated by He et al. (2017), Wang et al. (2018), and
Zhang et al. (2018). Mass pull of approximately 30% to the
graphite concentrate was possible. True flotation concen-
trate grade, recovery, and losses were not provided. Salces et
al. (2022), using a pyrolyzed black mass at 500°C, achieved
85% graphite recovery with 20% Ni-Mn-Co losses in
the graphite rougher concentrate. The authors noted that
Ni-Mn-Co losses were reduced by over 20% with attrition
prior to flotation.
