3344 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
vehicle replacement of internal combustion engine vehi-
cles (ICEs) [Zeng 2019, Katwala 2018, Agusdinata 2018]
have been discussed due to their use of conflict minerals,
[Deberdt 2021] water overconsumption during processing,
[Liu 2019, Liu 2020] and the creation of new extraction
economies. [Crawford 2021]. Despite concerns, produc-
tion of Li-ion batteries continues unabated.
Layered Double Hydroxides (LDHs) are a broad fam-
ily of “anionic clays” that have been known for 160 years.
Studies over that time have covered a variety of topics from
novel synthesis, characterization of unique structure, and
a staggering number of applications. LDHs can incorpo-
rate any variety of metals from across the periodic table to
form single to multi-metal layered structures. This comes
from the variety of oxidation states that allow metals to mix
and match with each other in M(II)/M(III), M(II)/M(IV),
and M(I)/M(III) configurations. These arrangements
allow for metal combinations that perform in applica-
tions related to electro, [Anantharaj 2017, Karmakar
2021] photo,[Mohapatra 2016, Wu 2018] and photoelec-
trocatalysis. [Ye 2021] LDHs rely on two main structural
components for their formation as well as application, the
repeating metal hydroxide layer and the water interlayer
that divides each metal layer. The metal layer offers basic
reaction sites as well as vacancies for ion insertion. The
water interlayer provides a channel that allows for water and
other ions to travel freely through the structure, giving rise
to interactions between the metal layer, passing ions, and
other host-guest interactions. Alteration of the interlayer
allows for other applications of LDHs to be used in pho-
tofunctional, [Tian 2015] biological, [Mishra 2018] and
other multifunctional applications. [Taviot-Gueho 2018]
Lithium-aluminum layered double hydroxide chloride
has been found as an attractive candidate for the exploita-
tion of geothermal and terrestrial brines. The application
of this material has become a topic of much interest in the
past 6 years. [Paranthaman 2017, Li 2018] Structural stud-
ies, [Wu 2019, Wu 2019] performances in different brine
compositions, and application development have been
widely explored. The mechanism of lithium extraction pro-
cess using Li-Al-LDH and iron-doped LDH sorbents is not
well understood. Hence, there is a need to study funda-
mental understanding of the role of structural water in the
lithiation process using neutron scattering studies. Here we
aim to explain the role of interlayer water movement on
Li-Al LDH structural properties and dynamic ion trans-
port processes. Using a variety of specialized techniques,
we explored the atomic and structural properties of water
within Li-Al LDHs prepared from aluminum hydrox-
ide (Al(OH)3-LDH), alumina (Al2O3-LDH) starting
materials, and an iron-doped LDH variant (Fe-LDH).
Here we investigate properties of Li-Al LDH with a unique
neutron scattering method. Quasi-elastic neutron scatter-
ing (QENS) techniques have been previously shown to
elucidate detailed information of the structural locations
and movement of hydrogen. [Cheng 2017, Liu 2019]
Other methods to investigate structural transformations in
Li-Al LDHs have utilized Magic Angle Spinning Nuclear
Magnetic Resonance Spectroscopy (MAS NMR). [Graham
2019] During QENS analysis, temperatures can be altered,
which allows for the determination of water dynamics and
subsequently the temperature dependence of water diffu-
sion for the material. [Melchior 2019] This is the first time
that direct calculations have been performed to view what
occurs structurally in Li-Al LDHs and its interlayer water.
Combined with the behavior of bulk water, this provides us
a clear dynamic picture of this material.
EXPERIMENTAL METHODS
Synthesis, sample preparation, and characterization of sam-
ples (X-ray diffraction (XRD), Attenuated Total Reflectance
Fourier Transform-Infrared Spectroscopy (ATR FT-IR),
Differential Scanning Calorimetry-Thermal Gravimetric
Analysis (DSC-TGA), High-Temperature Calorimetry,
Scanning Electron Microscopy (SEM) and Inelastic
Neutron Scattering (INS) of Li-Al LDHs and Fe-doped
LDH for lithium adsorption selectivity, [Paranthaman
2017] thermodynamic analysis, [Wu 2019] and neutron
analysis [Wu 2019] have been described previously. This
study was focused mainly on the Quasi-elastic neutron
scattering (QENS) studies on three adsorbent materials,
namely Li-Al LDH derived from two different starting
materials (Aluminum oxide, Al2O3 and Aluminum hydrox-
ide, Al(OH)3) and Fe-doped Li-Al LDH towards studying
the ordering of interlayer water molecules.
Quasi-Elastic Neutron Scattering (QENS) Experiments
Neutron backscattering measurements of Al2O3 and
Al(OH)3 derived Li-Al LDH were performed at BASIS
spectrometer [Mamontov 2011] at the Spallation Neutron
Source of Oak Ridge National Laboratory, Oak Ridge, TN.
Si(111) analyzers were utilized and the center wavelength
of neutron beam was 6.4 Å, giving energy resolution of
3.5 μeV (FWHM of the elastic peak), dynamic range of
±100 μeV and Q range from 0.2 to 2.0 Å–1. With this con-
figuration, the time scales from 1 ps to about 1 ns can be
observed, as well as length scale from about 3 up to 30 Å.
Each sample (500 mg) was distributed in an aluminum foil
pouch which was then wrapped inside a standard annular
aluminum can. To determine the instrumental resolution
vehicle replacement of internal combustion engine vehi-
cles (ICEs) [Zeng 2019, Katwala 2018, Agusdinata 2018]
have been discussed due to their use of conflict minerals,
[Deberdt 2021] water overconsumption during processing,
[Liu 2019, Liu 2020] and the creation of new extraction
economies. [Crawford 2021]. Despite concerns, produc-
tion of Li-ion batteries continues unabated.
Layered Double Hydroxides (LDHs) are a broad fam-
ily of “anionic clays” that have been known for 160 years.
Studies over that time have covered a variety of topics from
novel synthesis, characterization of unique structure, and
a staggering number of applications. LDHs can incorpo-
rate any variety of metals from across the periodic table to
form single to multi-metal layered structures. This comes
from the variety of oxidation states that allow metals to mix
and match with each other in M(II)/M(III), M(II)/M(IV),
and M(I)/M(III) configurations. These arrangements
allow for metal combinations that perform in applica-
tions related to electro, [Anantharaj 2017, Karmakar
2021] photo,[Mohapatra 2016, Wu 2018] and photoelec-
trocatalysis. [Ye 2021] LDHs rely on two main structural
components for their formation as well as application, the
repeating metal hydroxide layer and the water interlayer
that divides each metal layer. The metal layer offers basic
reaction sites as well as vacancies for ion insertion. The
water interlayer provides a channel that allows for water and
other ions to travel freely through the structure, giving rise
to interactions between the metal layer, passing ions, and
other host-guest interactions. Alteration of the interlayer
allows for other applications of LDHs to be used in pho-
tofunctional, [Tian 2015] biological, [Mishra 2018] and
other multifunctional applications. [Taviot-Gueho 2018]
Lithium-aluminum layered double hydroxide chloride
has been found as an attractive candidate for the exploita-
tion of geothermal and terrestrial brines. The application
of this material has become a topic of much interest in the
past 6 years. [Paranthaman 2017, Li 2018] Structural stud-
ies, [Wu 2019, Wu 2019] performances in different brine
compositions, and application development have been
widely explored. The mechanism of lithium extraction pro-
cess using Li-Al-LDH and iron-doped LDH sorbents is not
well understood. Hence, there is a need to study funda-
mental understanding of the role of structural water in the
lithiation process using neutron scattering studies. Here we
aim to explain the role of interlayer water movement on
Li-Al LDH structural properties and dynamic ion trans-
port processes. Using a variety of specialized techniques,
we explored the atomic and structural properties of water
within Li-Al LDHs prepared from aluminum hydrox-
ide (Al(OH)3-LDH), alumina (Al2O3-LDH) starting
materials, and an iron-doped LDH variant (Fe-LDH).
Here we investigate properties of Li-Al LDH with a unique
neutron scattering method. Quasi-elastic neutron scatter-
ing (QENS) techniques have been previously shown to
elucidate detailed information of the structural locations
and movement of hydrogen. [Cheng 2017, Liu 2019]
Other methods to investigate structural transformations in
Li-Al LDHs have utilized Magic Angle Spinning Nuclear
Magnetic Resonance Spectroscopy (MAS NMR). [Graham
2019] During QENS analysis, temperatures can be altered,
which allows for the determination of water dynamics and
subsequently the temperature dependence of water diffu-
sion for the material. [Melchior 2019] This is the first time
that direct calculations have been performed to view what
occurs structurally in Li-Al LDHs and its interlayer water.
Combined with the behavior of bulk water, this provides us
a clear dynamic picture of this material.
EXPERIMENTAL METHODS
Synthesis, sample preparation, and characterization of sam-
ples (X-ray diffraction (XRD), Attenuated Total Reflectance
Fourier Transform-Infrared Spectroscopy (ATR FT-IR),
Differential Scanning Calorimetry-Thermal Gravimetric
Analysis (DSC-TGA), High-Temperature Calorimetry,
Scanning Electron Microscopy (SEM) and Inelastic
Neutron Scattering (INS) of Li-Al LDHs and Fe-doped
LDH for lithium adsorption selectivity, [Paranthaman
2017] thermodynamic analysis, [Wu 2019] and neutron
analysis [Wu 2019] have been described previously. This
study was focused mainly on the Quasi-elastic neutron
scattering (QENS) studies on three adsorbent materials,
namely Li-Al LDH derived from two different starting
materials (Aluminum oxide, Al2O3 and Aluminum hydrox-
ide, Al(OH)3) and Fe-doped Li-Al LDH towards studying
the ordering of interlayer water molecules.
Quasi-Elastic Neutron Scattering (QENS) Experiments
Neutron backscattering measurements of Al2O3 and
Al(OH)3 derived Li-Al LDH were performed at BASIS
spectrometer [Mamontov 2011] at the Spallation Neutron
Source of Oak Ridge National Laboratory, Oak Ridge, TN.
Si(111) analyzers were utilized and the center wavelength
of neutron beam was 6.4 Å, giving energy resolution of
3.5 μeV (FWHM of the elastic peak), dynamic range of
±100 μeV and Q range from 0.2 to 2.0 Å–1. With this con-
figuration, the time scales from 1 ps to about 1 ns can be
observed, as well as length scale from about 3 up to 30 Å.
Each sample (500 mg) was distributed in an aluminum foil
pouch which was then wrapped inside a standard annular
aluminum can. To determine the instrumental resolution