Selective lithium extraction from clay minerals using a superacidic urea–methanesulfonic acid deep eutectic solvent
Selective lithium extraction from clay minerals using a superacidic urea–methanesulfonic acid deep eutectic solvent
Urea–methanesulfonic acid (MSA) deep eutectic solvents (DESs) are reported here for the first time as a green, superacidic platform for the highly selective extraction of lithium (Li) from clay-bearing ores. Formulated in molar ratios from 1:2 to 1:8, these DESs were characterized using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, 1H and 13C nuclear magnetic resonance (NMR), ultraviolet-visible (UV–Vis) spectroscopy, alongside density functional theory (DFT) to map their unique molecular interactions and tuneable acidity. Spectroscopic and computational analyses revealed a transition from hydrogen-bond-dominant to ionic environments as the MSA ratio increased, with DFT indicating rising interaction energies (1.583 to 3.237 eV) and vibrational signatures of protonation. The urea-MSA 1:2 system, optimized with 20% water, maintained superacidity (H0 = −3.102) and achieved a remarkable 100% extraction efficiency for Li, Na, and Sr. Critically, the system exhibited superior selectivity, recovering 100% Li while leaching only 23% Al and 6% K, significantly outperforming conventional sulfuric acid (4% Li) and citric acid (92% Li). This selectivity is attributed to a “coordination window” where the superacidic protons effectively disrupt the mineral lattice while the DES components inhibit the total dissolution of structural impurities. These findings demonstrate that urea-MSA DESs serve as high-performance, recyclable, and sustainable alternatives for the selective recovery of critical metals. By operating at moderate temperatures with high atom economy, this system offers a viable industrial pathway for the green valorization of complex mineral matrices, addressing the urgent need for sustainable lithium sourcing in the global energy transition.
Acidity, Clay mineral, Deep eutectic solvent (DES), DFT, Metal extraction, Methanesulfonic acid (MSA), Spectroscopic characterization
Ghaedi, Hosein
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Araya, Cristian Serrano
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Kalhor, Payam
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Dawson-Jones, Cora
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Ferrari, Enrico
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Munshi, Tasnim
584a9fb6-0f93-475d-935f-cf450332ba6a
Scowen, Ian
e7cf42d0-65b0-4fbe-b04d-eaa6718b9f5c
Ghorbani, Yousef
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6 February 2026
Ghaedi, Hosein
aabcd409-5a73-491d-93ef-1194ea65da2d
Araya, Cristian Serrano
879b6abc-93a1-452c-9cc9-e3b3cfa28a30
Kalhor, Payam
ab08ec78-2042-4beb-8dd1-5274bf91f8c7
Dawson-Jones, Cora
854abd42-aac5-4f9b-ab16-87808644582f
Ferrari, Enrico
61d9f8d5-7447-4798-9493-2e178ab75025
Munshi, Tasnim
584a9fb6-0f93-475d-935f-cf450332ba6a
Scowen, Ian
e7cf42d0-65b0-4fbe-b04d-eaa6718b9f5c
Ghorbani, Yousef
0a9c7c8a-342f-4b4a-a339-cbc31c94de8f
Ghaedi, Hosein, Araya, Cristian Serrano, Kalhor, Payam, Dawson-Jones, Cora, Ferrari, Enrico, Munshi, Tasnim, Scowen, Ian and Ghorbani, Yousef
(2026)
Selective lithium extraction from clay minerals using a superacidic urea–methanesulfonic acid deep eutectic solvent.
Separation and Purification Technology, 391, [137148].
(doi:10.1016/j.seppur.2026.137148).
Abstract
Urea–methanesulfonic acid (MSA) deep eutectic solvents (DESs) are reported here for the first time as a green, superacidic platform for the highly selective extraction of lithium (Li) from clay-bearing ores. Formulated in molar ratios from 1:2 to 1:8, these DESs were characterized using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, 1H and 13C nuclear magnetic resonance (NMR), ultraviolet-visible (UV–Vis) spectroscopy, alongside density functional theory (DFT) to map their unique molecular interactions and tuneable acidity. Spectroscopic and computational analyses revealed a transition from hydrogen-bond-dominant to ionic environments as the MSA ratio increased, with DFT indicating rising interaction energies (1.583 to 3.237 eV) and vibrational signatures of protonation. The urea-MSA 1:2 system, optimized with 20% water, maintained superacidity (H0 = −3.102) and achieved a remarkable 100% extraction efficiency for Li, Na, and Sr. Critically, the system exhibited superior selectivity, recovering 100% Li while leaching only 23% Al and 6% K, significantly outperforming conventional sulfuric acid (4% Li) and citric acid (92% Li). This selectivity is attributed to a “coordination window” where the superacidic protons effectively disrupt the mineral lattice while the DES components inhibit the total dissolution of structural impurities. These findings demonstrate that urea-MSA DESs serve as high-performance, recyclable, and sustainable alternatives for the selective recovery of critical metals. By operating at moderate temperatures with high atom economy, this system offers a viable industrial pathway for the green valorization of complex mineral matrices, addressing the urgent need for sustainable lithium sourcing in the global energy transition.
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More information
Accepted/In Press date: 2 February 2026
e-pub ahead of print date: 3 February 2026
Published date: 6 February 2026
Keywords:
Acidity, Clay mineral, Deep eutectic solvent (DES), DFT, Metal extraction, Methanesulfonic acid (MSA), Spectroscopic characterization
Identifiers
Local EPrints ID: 510548
URI: http://eprints.soton.ac.uk/id/eprint/510548
ISSN: 1383-5866
PURE UUID: f38790d4-4bd8-4a04-892a-f4f995fb980c
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Date deposited: 13 Apr 2026 16:44
Last modified: 14 Apr 2026 02:14
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Contributors
Author:
Hosein Ghaedi
Author:
Cristian Serrano Araya
Author:
Payam Kalhor
Author:
Cora Dawson-Jones
Author:
Enrico Ferrari
Author:
Tasnim Munshi
Author:
Ian Scowen
Author:
Yousef Ghorbani
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