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Open AccessArticle

A Machine Learning-Based Study of Li⁺ and Na⁺ Metal Complexation with Phosphoryl-Containing Ligands for the Selective Extraction of Li⁺ from Brine

by Natalia Kireeva, Vladimir E. Baulin and Aslan Yu. Tsivadze

ChemEngineering 2023, 7(3), 41; https://doi.org/10.3390/chemengineering7030041 - 1 May 2023

Cited by 6 | Viewed by 3559

Abstract

The growth of technologies concerned with the high demand in lithium (Li) sources dictates the need for technological solutions garnering Li supplies to preserve the sustainability of the processes. The aim of this study was to use a machine learning-based search for phosphoryl-containing podandic ligands, potentially selective for lithium extraction from brine. Based on the experimental data available on the stability constant values of phosphoryl-containing organic ligands with Li

^{+}

and Na

^{+}

cations at 4:1 THF:CHCl

_{3}

, candidate di-podandic ligands were proposed, for which the stability constant values (logK) with Li

^{+}

and Na

^{+}

as well as the corresponding selectivity values were evaluated using machine learning methods (ML). The modelling showed a reasonable predictive performance with the following statistical parameters: the determination coefficient R

^{2}

= 0.75, 0.87 and 0.83 and root-mean-square error RMSE = 0.485, 0.449 and 0.32 were obtained for the prediction of the stability constant values with Li

^{+}

and Na

^{+}

cations and Li

^{+}

/Na

^{+}

selectivity values, respectively. This ML-based analysis was complemented by the preliminary estimation of the host–guest complementarity of metal–ligand 1:1 complexes using the HostDesigner software. Full article

(This article belongs to the Collection Green and Environmentally Sustainable Chemical Processes)

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16 pages, 3411 KB

Open AccessArticle

Recovery of Uranium, Thorium, and Other Rare Metals from Eudialyte Concentrate by a Binary Extractant Based on 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and Methyl Trioctylammonium Nitrate

by Alfiya M. Safiulina, Alexey V. Lizunov, Aleksandr A. Semenov, Dmitriy V. Baulin, Vladimir E. Baulin, Aslan Yu. Tsivadze, Sergey M. Aksenov and Ivan G. Tananaev

Minerals 2022, 12(11), 1469; https://doi.org/10.3390/min12111469 - 20 Nov 2022

Cited by 8 | Viewed by 2827

Abstract

Eudialyte-group minerals are of scientific interest as important concentrators of rare elements (mainly Zr and REE) in agpaitic alkaline rocks and a potential source of REE, Zr, Hf, Nb, and Ta for industrial use. Extraction of uranium(VI), thorium(IV), zirconium(IV), hafnium(IV), titanium(IV), and scandium(III) by a binary extractant based on 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and methyl trioctylammonium nitrate from eudialyte breakdown solutions is studied. Extraction isotherms were obtained and exhaustive extraction was investigated. It is shown that uranium, thorium, hafnium, zirconium, scandium, and titanium are almost completely recovered in two-stage extraction by a mixture of 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and methyltrioctylammonium nitrate in 1,2-dichloroethane. Quantitative characteristics were compared for uranium(VI), thorium(IV), zirconium(IV), hafnium(IV), titanium(IV), and scandium(III). It was shown that the extraction efficiency of the metals by the binary extractant based on 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and methyltrioctylammonium nitrate in 1,2-dichloroethane is much higher in comparison with the commercially available tributyl phosphate. Full article

(This article belongs to the Special Issue Study of the Eudialyte Group Minerals)

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24 pages, 7218 KB

Open AccessArticle

Design of Extractants for F-Block Elements in a Series of (2-(Diphenylphosphoryl)methoxyphenyl)diphenylphosphine Oxide Derivatives: Synthesis, Quantum-Chemical, and Extraction Studies

by Alfiya Safiulina, Nataliya Borisova, Mikhail Grigoriev, Dmitriy Baulin, Vladimir Baulin and Aslan Tsivadze

Molecules 2021, 26(8), 2217; https://doi.org/10.3390/molecules26082217 - 12 Apr 2021

Cited by 6 | Viewed by 2971

Abstract

With the aim to find new efficient extractants for recovery of f-block elements from processing wastes of different origin, we have compared a series of phosphoryl-containing podands, including (2-(diphenylphosphorylmethoxy)phenyl)diphenylphosphine oxide 1 and its analogues 5–7, where the ArP(O)Ph₂ group of phosphine oxide type is replaced by phosphonic fragments. Quantum-chemical modelling of the structures of phosphoryl-containing podands 1 and 5–7 has been performed, which was later confirmed by the data of X-ray diffraction. The features of extraction of nitric acid, as well as U(VI), Th(IV), Nd(III), and Ho(III) with compounds 1 and 5–7 from nitric acid media into 1,2-dichloroethane have been studied. The compositions of extracted complexes have been determined. Full article

(This article belongs to the Special Issue Recent Developments in the Synthesis and Utilization of Organophosphorus Compounds)

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