Dialkyl(5-ethyl-2-hydroxyphenyl)phosphonates as extractants for the selective recovery of lithium from alkaline media

• Published in: Desalination Vol. 579; p. 117446
• Main Authors: Bezdomnikov, A.A., Demina, L.I., Baulin, V.E., Sharov, V.E., Tarakanova, E.G., Tsivadze, A. Yu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 29.06.2024
• Subjects: 2-Hydroxyphenylphosphonates; Brine; DFT calculations; Liquid extraction; Lithium; Lithium; 2-Hydroxyphenylphosphonates; Liquid extraction; DFT calculations; Brine
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2024.117446

O,O′-dialkyl(5-ethyl-2-hydroxyphenyl)phosphonates (HL) in combination with the synergistic additive, trioctylphosphine oxide (TOPO), were considered as lithium-selective extractants for the first time. The possibility of these compounds to exhibit lithium-selective properties in the extraction of alkali metals (Li, Na, K) was predicted by quantum chemical calculations, the results of which were confirmed by extraction experiments. It is shown that the composition of the extracted species can vary depending on the extraction conditions. At the same time, O,O′-dialkyl(5-ethyl-2-hydroxyphenyl)phosphonates can participate in extraction both as cation-exchange extractants and as neutral extractants, competing with TOPO. •A new lithium-selectivity extraction system based on 2-hydroxyphenylphosphonates and TOPO was proposed.•The compositions of extractable alkali metal complexes were determined•Thermodynamic parameters of extraction reactions and extractant transition to the aqueous phase were determined•It is shown that 2-hydroxyphenylphosphonates can participate in extraction as cation exchangers and neutral extractants