Hydrophobic organic liquid composition for the selective extraction of a lithium salt

Abstract

The present invention relates to a hydrophobic organic liquid composition for the selective extraction of a di-ionic lithium salt comprising a lithium cation and an anion complementary to the lithium cation, chosen in particular from Cl, I, Br, CN, MK and HCO 3, from a lithium-rich brine to be treated, said composition comprising (A) at least one compound extracting the lithium cation, chosen from the compounds of formula: (I) in which R1, R2, R3, R4, R5 and R6 are as defined in the description; (B) at least one organic, protic and hydrophobic compound solvating the anion complementary to the lithium cation; and (C) at least one hydrophobic polar organic diluent having a flash point at atmospheric pressure greater than 60°C, preferably greater than 75°C, more preferably greater than 90°C.

Description

Title of invention: Hydrophobic organic liquid composition for the selective extraction of a lithium salt. The present invention relates to a hydrophobic organic liquid composition for the selective extraction of a lithium salt. As part of the energy transition, the global objective of replacing vehicles that emit 20% of the world's CO2 with electric vehicles means that the global production of metals such as lithium, nickel, cobalt, copper and manganese will have to be increased many-fold. In particular, lithium, which is essential for the construction of lithium-ion batteries, should see its production increase fourfold between 2020 (990 kt lithium carbonate equivalent (LCE)) and 2030 (3,700 kt LCE) to build sixteen times as many electric vehicles and to supply more than three hundred new battery factory projects. As a result of this very strong demand outstripping supply, the price of lithium has risen from US$16,750 / ton LCE in 2018 to US$71,750 / ton LCE in 2022. This excess demand is not likely to abate quickly, however, because lithium mining production capacity is unable to keep pace with demand. Although lithium is widely available on earth, either in the form of mineral rock (Spodumene, Lepidolite, Petalite, etc.) or in the form of a salt (LiCl, Li2SO4 , etc.) dissolved or undissolved in water, its extraction (186 kt Li) is still relatively modest compared with the other metals involved in the energy transition, which can be counted in millions of tons (Iron: 1,500 Mt; Aluminum: 65 Mt; Copper: 20 Mt; Manganese: 19 Mt; Zinc: 12 Mt; Chromium: 12 Mt; Titanium: 8 Mt; Lead: 4.7 Mt; Nickel: 4.7 Mt). In particular, lithium-rich brines are generally taken from the natural environment as continental brines from Andean or Tibetan endoreic basins, oil production water brines, geothermal brines and others. In current applications, salt mines with high concentrations of LiCl use salt marshes to evaporate the water from the brines extracted from the subsoil and reconcentrate the lithium from 200-2000 mg / L to more than 50 g / L and even up to 80 g / L. This phase is carried out in hundreds of hectares of evaporation ponds that take a long time to build (3 to 4 years) and that must be maintained over time to prevent leaks and infiltration. What's more, this natural evaporation is dependent on sunshine and the general climate, with a reconcentration phase lasting 12 to 24 months from the well to the production of this concentrate, generating variability in production, both in terms of volume and quality, associated with millions of tons of crystallised salt (NaCl, Na2SO4 , K3Na(SO4)2, KCl, Na2Mg(SO4)2.4H2O...) that need to be evacuated regularly to maintain evaporation-crystallisation capacity. After this initial phase, a lithium concentrate is obtained that can incorporate all the ions from the initial brine, which now requires a number of downstream brine treatment stages to remove mineral impurities other than lithium in order to finally obtain the desired lithium, generally in the form of Li2CO3 after carbonation. After these solar evaporation basins, it is common to operate several units in series to extract boron by liquid-liquid extraction, then to chemically precipitate calcium, magnesium and sulphates, followed by a KCl crystalliser, then ion exchange resins and finally the final carbonation unit. This separates residual sodium Na+ and lithium Li+ by precipitating lithium carbonate Li2CO3 at 80°C with the addition of sodium carbonate Na2CO3: LiCl(aq) + Na2CO3(s) => Li2CO3(s) + NaCl(aq). The presence of sodium in the concentrated LiCl brine as obtained also makes it impossible to produce battery-grade LiOH.H2O directly. It is therefore used after an initial carbonation of LiCl into Li2CO3, a second carbonation after redissolving the latter to achieve a sufficient level of purity of Li2CO3 before its chemical conversion by electrolysis into LiOH or by adding Ca(OH)2 via: Ca(OH)2(aq) + Li2CO3(s) => 2 LiOH(aq) + CaCO3(s). Being able to convert LiCl directly into LiOH.H2O would reduce operating costs (OPEX) by at least US$2,500 / ton LiOH.H2O, making this process much more competitive. This production method has to improve productivity, lithium yield and purity, and cost if it is to keep pace with the strong demand for lithium, while at the same time delivering first-rate Environmental, Social and Governance (ESG) results. For example, because of the high water consumption caused by the evaporation of brine, there are increasing restrictions in producer countries, led by Chile, on maintaining solar evaporators, which are considered potentially unsustainable on very arid Andean plateaux (15 to 100 mm rainfall / year). Other historical problems with the production of lithium from brines are also known in China, Bolivia and, to a lesser extent, Argentina, due to brine compositions that are too rich in magnesium and / or sulphate. For example, when a mass ratio of Mg / Li > 6 is reached, lithium can co-precipitate with magnesium due to similar physical and chemical properties that make it difficult to separate them (precipitates of carnalite (MgCl2.KCl.6H2O), bischofite (MgCl2.6H2O), lithium carnalite (LiCl.MgCl2.7H2O), etc.). In China, for example, in the region of the Qinghai Tibetan highlands, Mg / Li ratios of 10 to 40 are common, and even up to 100. Furthermore, in the strong presence of sulphate, other combined salts can incorporate lithium and generate its loss by co-precipitation (precipitates of Astrakanite (Na2Mg(SO4)2.4H2O), Schoenite (K2Mg(SO4)2.6H2O), Leonite (K2Mg(SO4)2.4H2O), Kainite (MgSO4.KCl.3H2O), Epsomite (MgSO4.7H2O)...). This solar reconcentration step can generate from 40% to more than 70% lithium losses through the coprecipitation and the washing away of lithium-rich brine, which can lead to such a high lithium loss in some brines that the process becomes uneconomical and environmentally unfriendly. Lithium in brines is estimated to account for 75-80% of the world's lithium resources, well ahead of the Pegmatite mines. The purpose of the invention is to resolve all these difficulties by using a solution for the selective extraction of LiCl from brines in the presence of many other salts, in particular NaCl, KCl, CaCl2, MgCl2, SrCl2, Na2SO4, K2SO4, NaH2BO3, KH2BO3... So rather than treating all the impurities in the brine, which make up the vast majority, the aim of the invention is to extract only the desired salt, in this case LiCl, and thus significantly improve all the technical and economic parameters shown in Table 1. [Table 1] Parameter considered Unit State of the art Lithium extraction yield % 30 - 50% Consumption of extracted brine m3 / t Li2CO3 125 - 900 Fresh water consumption m3 / t Li2CO3 16 - 100 Process ground area hectare 400 - 2 000 Displaced salts (NaCl, MgC12, CaSO4...) tonne / t L12CO3 50 - 500 Chemical Reagents (HC1, H2SO4, CaO) kg / t Li2CO3 100 - 4 000 Heat (NG or Diesel) kWh / t Li2CO3 3 000 - 8 500 Electricity kWh / t Li2CO3 500 - 1 200 C02 emissions tonne / t Li2CO3 4-5 Time to market for new capacity years 5-6 (minimum) Investment costs, CAPEX kUS$ / (t Li2CO3 / yr) 16 - 28 Operating costs, OPEX US$ / t Li2CO3 3 050 - 4 600 To this end, the invention aims to implement a liquidliquid extraction solution by presenting an organic formulation enabling the selective extraction of di-ionic lithium salts (salts with one anion and one monovalent cation) in the presence of numerous other dissolved inorganic compounds, chosen at least from alkalis, alkaline earth metals, halogens, sulphates, carbonates and other borates. The use of liquid-liquid extraction for the selective extraction of lithium from natural or artificial brines has been studied for many years. For example, patent US 3,306,712 describes the use of alcohols or ketones for the selective extraction of LiCl, LiBr or LiI from CaCl2 brine with regeneration of the solvent with water in the presence of urea to extract the co-extracted CaCl2. Gabra and Torma [1] studied the extraction of LiCl, NaCl, KCl and CaCl2 by a number of alcohols, showing separation coefficients (Li, Na), (Li, K) and (Li, Ca) of less than 3.21, 2.9 and 9.17 respectively. The best performing alcohol was n-butanol despite relatively high co-absorption of CaCl2. Overall, the solubility of LiCl increases as the molar mass of the alcohol decreases, but this molar mass must be increased to reduce the solubility of the alkaline-earth chlorides, MgCl2 and CaCl2. Bukowsky and Uhlemann [2] proposed the use of solvent mixtures of isopentyl alcohol combined with 2-ethyl-1,3-hexane, diisopropyl ether or diethyl ether to greatly reduce the coextraction of alkaline-earth chlorides, but this was to the detriment of LiCl extraction with products that were ultimately far too soluble in water. Patent US 3,793,433 proposed solvent extraction of lithium using halogenated |3-diketone and trioctylphosphine oxide (TOPO) in benzene with acid regeneration (0.15 N HCl). Separation factors (SF) in excess of 1,000 are given in relation to the other alkali metals Na+, K+, Rb+ and Cs+ but this extractant extracts the alkaline earth metals Mg2+ and Ca2+ much more favourably than lithium (SF < 0.07) making the selective extraction of lithium impossible from any natural brine which always contains alkaline earth metals. The use of acid extractants of the 2-ethylhexylphosphonic acid (D2EHPA) type encounters this same difficulty because, although experimental data indicate that the Li-D2EPHA complex has a high selectivity compared with other monovalent metal ions and that the addition of tributyl phosphate (TBP) has a synergistic effect in increasing lithium extraction, these acid extractants preferentially extract alkaline-earth metals compared with alkali metals ([3]). Thus, the commercial acid extractants MEHPA, D2EHPA, Cyanex 272, PC88A, lonquest 801 and others are not suitable for the selective extraction of lithium in the presence of alkaline earth metals. Gao et al [4] looked at the use of imidazolium-based ionic liquids with carbon chains of 4 to 9 carbons in the presence of tri-iso-butyl phosphate (TIBP). The formation of the [Li.2TIBP]+org complex was established with an acid regeneration by cation exchange H+ / Li+ but the lithium extraction phase is carried out by cation exchange of the ionic liquid (C4 min+ ) / Li+ which does not allow the extraction performance to be maintained over time by decomposition of the ionic liquid. Patent CN106498184 proposes the use of N-methyl-N-(N'-2-ethylcarbonyl-ethylpyrrole hexafluorophosphate as an ionic liquid. The patent gives no indication of the conditions for extracting and desorbing LiCl. Another approach was to study neutral organophosphorus extractants in the presence of the co-extraction agent Fer(III). The TBP / methyl isobutyl ketone (MIBK) / FeCl3 system ([5]) attracted attention due to the extractability of the Li+FeCl4-couple in the presence of neutral oxygen-donor extractants. A liquid-liquid extraction process using this lithium extraction ternary was evaluated ([6]). The process appears to be complex because of the need to avoid loss of hydrophilic Fe3+ by maintaining an aqueous environment with a high concentration of chloride anion Cl- and acid (to avoid precipitation of Fe(OH)3(s)) in the washing and de-extraction phases (1 t HCl / t LiCl). In addition, NaOH was used to regenerate the formulation before extraction (2 t NaOH / t LiCl). As an alternative to TBP, other neutral extractants were studied, such as N,N-bis(2-ethylhexyl) acetamide (N523) ([7]). To avoid using iron(III), Zhou et al ([8]) proposed the use of sodium phosphomolybdate with a heteropolyacid structure as a coextraction agent in combination with TBP / MIBK. This approach enables a Na+ / Li+ exchange to be carried out during the extraction phase. A washing step is then carried out using a 2M mixture of LiCl + NaCl (10 / 90) to purge impurities K+ and Mg2+ by cation exchange. Next, the de-extraction step is carried out using 0.24 M HCl acid to obtain an acidic LiCl effluent. Finally, the organic phase must be neutralized using 0.26 M NaOH to enable it to be regenerated before being reused. This new cation exchange liquid-liquid extraction process, with its four phases of extraction, washing, de-extraction and regeneration, appears to be theoretically functional, but requires excellent operational control of the potential discharge of different forms of potentially toxic molybdenum, and involves high costs for chemical reagents. US2022 / 274956A1 proposes the use of three-dimensional calixpyrroles to encapsulate a salt, in particular LiCl, in the presence of NaCl and KCl for both solid-liquid and liquid-liquid extraction applications. There is no information on the impact of the presence of alkali metals on this extraction to know if this solution is really selective for lithium. The literature does not describe a liquid-liquid extraction solution that is selective towards lithium in the presence of alkali and alkaline-earth metals, that does not use chemical reagents and that can be industrialized in the short term (non-toxic, non-expensive products that are sufficiently insoluble in water, etc.). The present invention therefore relates to a hydrophobic organic liquid composition for the selective extraction of a diionic lithium salt comprising a lithium cation and an anion complementary to the lithium cation chosen in particular from Cl-, I-, Br-, CN-, NO3-, HCO3- from a lithium-rich brine to be treated, the said composition comprising: (A) at least one compound extracting the lithium cation, chosen from compounds of formula: \ •I in which: — R1 and R2, which may be identical or different, are, irrespective of their position on a nitrogen atom, independently selected from linear or branched C1-C12 alkyl, aryl, C4-C8 cycloalkyl; or — R1 and R2, taken together with the nitrogen atom carrying them, form a five-, six-, seven- or eight-membered ring; — R3 is selected from hydrogen, linear or branched C1-C8 alkyl,    C4-C8    cycloalkyl,    C2-C6    alkoxyalkyl and alkoxyalkylaryl; —   R4 is selected from hydrogen,  linear or branched C1-C3 alkyl; —   R5 is selected from hydrogen,  linear or branched C1-C3 alkyl; —  R6 is selected from hydrogen,  linear or branched C1-C3 alkyl; (B) at least one hydrophobic protic organic compound which solvates the anion complementary to the lithium cation; and (C) at least one hydrophobic polar organic diluent having a flash point at atmospheric pressure greater than 60°C, preferably greater than 75°C, more preferably greater than 90°C. By di-ionic lithium salt is meant a lithium salt comprising a lithium cation Li+, carrying a single positive charge, and a mono- or polyatomic anion carrying a single negative charge, such as for example the monoatomic anion Cl- or the polyatomic anion NO3-. The compound extracting the lithium cation may have a molar mass of at least 450 g / mol, preferably at least 550 g / mol. The compound extracting the lithium cation may have a complexation constant Log K for this cation in methanol at 25°C of at least 1, preferably greater than 2. The compound extracting the lithium cation may have a negative enthalpy variation upon complexation of the lithium cation, AH, associated with an absolute value of the ratio of the enthalpy variation upon complexation of the lithium cation AH to the entropy variation upon complexation of the lithium cation, AS, at temperature T=298K, |AH / (TAS)| greater than 2, preferably greater than 5. These values of enthalpy variation and entropy variation during lithium cation complexation, provide a value of free energy variation AG that is influenced more by the enthalpic component rather than its entropic component. This provides a compound extracting the lithium cation that can extract the lithium cation under cold conditions and be regenerated under hot conditions. The compound extracting the lithium cation may have a melting temperature of less than 200°C, preferably less than 50°C and more preferably less than 25°C. In a particular embodiment: — R1 and R2 may be, whatever their position on a nitrogen atom, independently selected from methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, 2-methylbutyl, 2-ethylpropyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, 2-ethylhexyl, phenyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl; or, — R1 and R2, taken together with the nitrogen atom carrying them, may form a pyrrolidine, piperidine, azepane or azocane ring; — R3 may be selected from hydrogen, methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, 2-methylbutyl, 2-ethylpropyl, n-hexyl, cyclohexyl, methoxymethyl, methoxyethyl, methoxypropyl, methoxybutyl and -CH2-O-CH2-Phenyl; and — R4, R5 and R6 may be hydrogen or methyl, R1 and R2 being advantageously chosen from butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl or phenyl if the brine to be treated has a calcium concentration of more than 10 g / L and / or the selectivity Li+ / Ca2+ is privileged; and R1 and R2 being advantageously chosen from iso-propyl, isobutyl, sec-butyl, tert-butyl, iso-pentyl, 2-methylbutyl, 2-ethylpropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl or R1 and R2, taken together with the nitrogen atom carrying them, form a pyrrolidine, piperidine, azepane or azocane ring when the brine to be treated has a calcium concentration of less than 10 g / L and / or when Li+ / Na+ selectivity is privileged. The compound extracting the lithium cation may be chosen from: / —\ ch3 oQbb^P ■ . ' ■ ' N---(       )   '----' (J an v on: an 0 Q on Oo a° ° »*—a ■no b CE00 CE01 CE02 h3c—\ \ /   0       —N a ch3 : 0 ■ , i aA.a.yfY> II CE03 CE04 CE05 p 0 o oJpo^ Q ah4r>O Oyay ba no < J — / o     —N   0         \    0           ' a an ^~~P^—b^b — CE06 CE07 CE08 Cabo + a o ch3 ayc> -^p O a °x a O           2     0     --CH3 a N---(      > ch3 G." . . . _. c °b / N-a o CE09 CE10 CE11 OOP o         A\ a b Q'T'-’-'b-j-a ' L '■ <0 Q-vyGro CE12 CE13 CE14 9 v ,----N ^b 0 zx / "x          / 1          II         Z\ / °x _-b\       b 0 / -4 b \___ o 1         Il          / X. Z°X bb / ^x b / Xx /  x^z X Z b CE15 CE16 CE17 \      0   r—\ __ -Z^x        / y /               1   \ / '^T 'if'               bb      / \ I         II                  / O              . / *-'. \ * o \___     ®    r""\ __ Z*X       / X /   '     ||        \ ii           / x z0^ b-v ^bx. / /    \z x^^ ' J' o 9 u . "T^b / b xb, bO cb-6 o CE18 CE19 CE20 ch3      ch3 € C h3c—,   ^CH3 V“\    h3c ch3 / —N   0— / / 0—\  )— Hac         o     yN o           /     0     / CH3 o=( CH3 ( h3c    n—(       ch3 \ch3 ch3 o£h £ho         / eH0^\       <7\ ' \     , 0 I ■—0      H '      OCH 0    -- / J " V  ’ £H0--'   /   / —M\ eHO^ ' £ho CH3          CHj HjC---<      y----( '---N       CHj b H3C                        I---4----1                       CHa / ^-° \   °^—\    / c H3C       N---A           CHa         A---N       CHa O  Q )— CHa                HaC^—( HaC                                       CH, CE21 CE22 CE23 ch3 0                0         / C6H13 r 9 Hi3C6-N^            }      0     c6h13 c6h13 / N C6H13 ^13^6 ch3 0                               / C|iHl7 / —    0      / / —N H^Cs-N,          \     0    XC8H17 CsH17 0=^ zn-c8h17 Hi / Cg ch3 - 0     0- /              / C10H21 / —0    #—N ^2iOio’N\           \      0     C10H2i C10H2i 0—( / N-C10H21 H21Ci0 CE24 CE25 CE26 yyy / y \         bb z°\ bx b \           / x^ x / xNx- ) O       O----'                      1 ,-----'         '----N 1 b^\ / / aX o     °^ \ 7—0     0 0      \---- b<A N-----1           ) CJ ^yy by / / yb 0      0--(   / —0      0 0^c CE27 CE28 CE29 ch3 0--\0--\       \ \ / hvJ o       2   ° x— 0=\ O x^A.           Aa /    X              _X        0 \   .n       / A< o. Xx A__ / Af 0 .xA / A / N 0           ’                       k o< / ■""""A                      -CHi /    X              s'        O \    ,N- / X          o_        /  \ x / O                N    \ o'     X / X---^ CE30 CE31 CE32 ch3 o / CH3 _y\x 9   9--N     O--' 2 0-->     CH3 ^=7 d^ °\ N—CHo     ^=7 d 9 %s^N\ / CH1 oAAddd '‘CHa ch3 0    0— / CsH13 / 7  °\   9 \ H3C-'nx          )     0      CH3 ^6^13 °~\ n-c6h13 h3c CE33 CE34 CE35 "X /            CH, «*>        h / ch3 0            °X / CbHi7 / —   0     X—N H3C-^nx          5     °      ^h3 c8h17 n-c8h17 h3c ch3 . O    O / 2 O \    / —ch3 0       —N / N           \     O     --CH3 h3A >   o=( HoC             N \ Oh3 ch3 CE36 CE37 CE38 Y     \    ° i N                           /                  II ri         z\ / A II                 / ° \ 0 X A yd ' ' / \ 9 .. :■. v '^y~ d^ ^-■a.X o       XX yd CE40 CE41 CE42 1 axJn Ad u :w 6 CE43 The hydrophobic and protic, organic compound, which a pKa in water at 25°C of at least 9, preferably at least 10.5 and preferably less than the pKa of water at 25°C, or at least less than 15 at 25°C and whose solubility in water at 25°C is less than 0.01 mol / l. The hydrophobic protic organic compound which solvates the anion complementary to the lithium cation may be a compound of formula (B): X Rc (B) in which: — at least one of the radicals Rb, Rc and Rd , which may be identical or different, is a halogen atom or an electronwithdrawing group selected from the following group: F, Cl, Br; CmF2m+1 with m < 4, where m is a non-zero integer; CF2CF2CPH2P+1 with p 4, where p is an integer; CF2CpH2p+1 with p < 4, where p is an integer; CH2CpF2p+1 with p < 4, where p is an integer; OCH2CF3; C(=O)CF3; CmHnFpClqBrs with m < 4, where n, p, q, s are integers of which at least p, q or s is non-zero; C(=O)OCmH2m+1 with m < 4, where m is an integer; and C(=O)CmH2m+1 with m < 4, where m is an integer; — the remaining radical(s) RA, RB, RC, RD and RE are chosen, identically or differently, from the following nonelectroattracting radicals: H; CH3; CH2CH3; CH2CH2CpF2p+1 with p 4, where p is an integer; CmH2m-1 with m 10, where m is an integer greater than 1; and CmH2m+1 with m 10, where m is a non-zero integer; where only one of the radicals RA to RE can be one of the latter two radicals CmH2m-1 and CmH2m+1; and — X is chosen from the following radicals: .OH; OH C—R' R" -; where RA, RB, RC, RD and RE, which may be identical or different, are as defined above in formula (B), where R' and R'', which may be identical or different, are selected from the following radicals: H; CnH2n-1 with n < 4, where n is an integer greater than 1; CnH2n+i with n < 4, where n is a non-zero integer; CH2CH2CpF2p+1 with p < 4, where p is an integer; CH2CpF2p+1 with p < 4, where p is an integer; CF2CpH2p+1 with p < 4, where p is an integer; CF2CF2CpH2p+1 with p d 4, where p is an integer; CmF2m+1 with m < 4, where m is a non-zero integer; CmHnFpClqBrs with m < 4, where n, p, q, s are integers where at least p, q or s is non-zero; and where R''' is selected from the following radicals: CmH2m+1 with m d 20, where m is an integer; CmH2m-1 with m 20, where m is an integer greater than 1; CmHnFpClqBrs with m d 10, where n, p, q, s are integers in which at least p, q or s is non-zero; CH2 CH2CpF2p+1 with p < 4, where p is an integer; CH2CpF2p+1 with p d 4, where p is an integer; CF2CpH2p+1 with p d 4, where p is an integer; CF2CF2CpH2p+1 with p < 4, where p is an integer; CmF2m+1 with m < 4, where m is a non-zero integer; and an aryl radical of formula (b): (b) where RA, RB, RC, RD and RE, which may be identical or different, are as defined above in formula (B). In particular, in the compound of formula (B) X may represent: Compound (B) can be represented by the formula: (C): or (D): in which R'' is chosen from the following radicals: CmH2m+1 with m < 20, preferably < 15 where m is an integer; CmH2m-i with m < 20, where m is an integer greater than 1; CmHnFpClqBrs with m i 10, where n, p, q, s are integers in which at least p, q or s is non-zero; and an aryl radical of formula (b): (b) where RA, RB, RC, RD and RE, which may be identical or different, are as defined in formula (B) above. In a particular embodiment, the radical R''' may be n- C7H15, n-C9H19, n-C11H23 or n-C13H27. The at least one compound extracting the lithium cation may be present in the composition at a concentration of 0.15 to 1 mol / L, preferably 0.3 to 1 mol / L, more preferably 0.45 to 1 mol / L. The ratio of the molar concentration of the at least one hydrophobic protic organic compound which solvates the anion complementary to the lithium cation to the molar concentration of the at least one compound which extracts the lithium cation may be from 1 to 10, preferably from 1.5 to 5 and more preferably from 2 to 4. The hydrophobic polar organic diluent may have a viscosity at 20°C of less than 5 mPa.s, preferably less than 2 mPa.s. Preferably, the hydrophobic polar organic diluent is an aromatic polar diluent. This aromatic diluent may be chosen from 2-chlorobromobenzene, 1,2-dibromobenzene, 2-bromotoluene or 3,4-dibromotoluene. The hydrophobic organic liquid composition may have a density at 20°C greater than 1.20 kg / L, preferably greater than 1.25 kg / L, more preferably greater than 1.30 kg / L, for a viscosity at 20°C of less than 50 mPa.s, preferably less than 25 mPa.s, for a brine to be treated with a density at 20°C at least 0.05 kg / L lower. The hydrophobic organic liquid composition may have a density at 20°C greater than 1.25 kg / L, preferably greater than 1.30 kg / L, more preferably greater than 1.35 kg / L, for a viscosity at 20°C of less than 30 mPa.s, preferably less than 15 mPa.s, for a brine to be treated with a density at 20°C at least 0.15 kg / L lower. The viscosity of the diluent and the hydrophobic organic liquid composition is measured using an Anton Paar Lovis 2000 viscometer. The sample is introduced into a capillary of known diameter. The measurement is carried out using a steel ball that moves more or less quickly through the capillary depending on the viscosity of the sample. The instrument detects the ball and measures the time it has taken to travel through the capillary at a certain angle. Calibrated beforehand using certified liquids, the device then provides a measurement of the viscosity in mPa.s. The density is measured using an Anton Paar DMA 4100M electronic density meter over a temperature range from 0 to 100°C. The points used here are those at 20°C. This apparatus is described, for example, in patents EP3012612 and EP3101409. The sample is introduced into a glass tube of precise volume. The tube vibrates. The period of the whole (tube + liquid) is determined. The instrument subtracts this period from the reference period of the empty glass tube to determine the period of the liquid in the glass tube. An abacus showing the period as a function of the density is used to determine the density of the liquid. The present invention also relates to a compound chosen H                         / -----> 0     0—7 }  0—K     }---' / --\ 9-- /   0       / -N /  \--N          \     0    \--, bgo c . °\XC ° if      \ eg / u / —\ / \ 44 ° o >bo " i J 4 o<l-nX 0 CE07 CE08 CE09 n o / v 4-( X YrXX^ 9 " ---H b ' b v -¾ CE11 CE12 CE13 ' $. " <b ’ 9 v ■X CE14 CE15 CE16 ’ X + b- ' 9 A ■b i.                    ii rA X       0              .-0._ . / ... x A X CE17 CE18 CE19 9 r , n /       'ft                  99. / 9^ / \     I                    / 3 -6 >--w o ch3      ch3 H3C--\   \—ch3  Y—<     h3c    ch3 / —N 0— / 0—\ H3C   \—'   0     \—N o7      )   07 Vch3 0=( CH3 ( h3c    n—(       ch3 \—(  4—ch3 ch3 ch3 0    0—7 \ 0—c6h. ° X h13c6-N\            }      o     c6h. c6h13 zn-c6h13 ^13^6 CE20 CE21 CE24 ch3 O             □—.    c8h17 r \ xN\ h17c8-n^          2     0     c8h17 c8h17 0=(^ / N—C8H17 h17c8 ch3 0   o— / p~0=   c10h2, / —   0    #—N\ H2iCi0-N\              >       0      C10H2-| c10h21 / N C10H21 h21cw V CE25 CE26 CE27 0 0--- / / --0 0 0 '----- 4 = d^ 0 0---( / --0 0 0 '------ / x d^ / -""■~X                     ,CHa /     X                 -<          0 \   JX Xx zXXj    o. dd. Pf  ° >Xx^X xX N 0           ’                       k X—• CE28 CE29 CE31 r" \                 ch3 /    X             s'        o \     N / "X. X^xJ         / d.      \ V o , / xX     N   \ o'     k / o                 X--—7 ch3 0   0—^P0=   c6h13 / \ ^N\ H3c—Nx          )     0     CH3 ^6^13 0=\ n-c6h13 h3c ch3 0 O—^P0=   c8h17 X °\ x\ H3C —)     0     CH3 c8h17 od n-c8h17 h8c CE32 CE35 CE37 ch3 o  o Jp0 =  ^ch3 / — 0      / / —N , N           \      0      --CH, .9 )  0=( HoC             N \ ( ^CH3 ch3 ii T 0                 X' f          II                  /                          N 0           \ o         x / \, / p >■ / p CE38 CE40 CE41 V         ° i ,N                    .--.      /                  II pX Tl        / x X Xx II        / XX XX 0 \ O         .XX P- / p 0        0---. J---0        0 d CE42 CE43 The present invention also relates to the use of the hydrophobic organic liquid composition described above in a lithium salt extraction process, the said process comprising a step of mixing, at a first temperature, the hydrophobic organic liquid composition and the brine to be treated, a step of separating the lithium salt-loaded hydrophobic organic liquid composition loaded with lithium salt and the treated brine and a step of regenerating the hydrophobic organic liquid composition by treating the hydrophobic organic liquid composition loaded with lithium salt with a treatment water, the said regeneration step being carried out at a second temperature, higher than the first temperature, the difference between the first temperature and the second temperature being from 30 to 150°C, preferably from 50 to 100°C, more preferably from 60 to 80°C. One of the aims of the invention is to be able to selectively extract LiCl from lithium-rich continental brines found in the Andean highlands of Chile, Argentina and Bolivia or the Tibetan highlands of China. Figure 1 shows the compositions, measured in mmol / L, of around twenty of these natural brines with an average density of 1.22 kg / L. According to these compositions, Li / Na selectivity appears to be the first decisive factor, followed by Mg / Li, Ca / Li and SO4 / Li selectivities. Compositions according to the invention may also be used to treat these brines after reconcentration by solar evaporation or other means. Ion Selective Electrodes (ISE) based on a polyvinyl chloride (PVC) lithium ion-selective membrane are available for measuring lithium concentration in aqueous solutions or in blood. In particular, the series of ionophores I to VIII is presented by Kamenica & al ([9]). Lithium ionophore I: N,N'-diheptyl-Nz7V', 5,5-tetramethyl-3,7-dioxanonanediamide,         or         2,2'-[(2,2-dimethyl-1,3- 5 propanediyl)bis(oxy)]bis[N-heptyl-N-methyl-Acetamide, ETH 149, CAS N°: 58821-96-8 Lithium ionophore II: N,N,N',N'-tetraisobutyl-cis-cyclohexane-1,2-dicarboxamide, ETH 1644, CAS N°: 80547-18-8 10 Lithium ionophore III: N,N-dicyclohexyl-N',N'-diisobutyl-cis-cyclohexane-1,2-dicarboxamide, ETH 1810, CAS N°: 99281-50-2 Lithium ionophore IV:   N,N,N’,N'-tetracyclohexyl-5-ethyl-5- 15 butyl-3,7-dioxanonanediamide,   or 2,2'-[(2-butyl-2-ethyl-1,3- propanediyl)bis(oxy)]bis[N,N-dicyclohexylacetamide], ETH 2137, CAS N°: 108083-23-4 Lithium ionophore V: 1,4,7,10-tetracyclododecane, or 12-crown-4, CAS N°: 294-93-9 Lithium       ionophore       VI:        6,6-dibenzyl-1,4,8,11- tetraoxacyclotetradecane, CAS N°: 106868-21-7 Lithium       ionophore       VII:       2-(6-dodecyl-1,4,8,11- tetraoxacyclotetradec-6-yl)ethyl diethyl phosphate, CAS N°: 106868-29-5 Lithium ionophore VIII: 2,2'-[[2-[[2-(Dicyclohexylamino)-2-oxoethoxy]methyl]-2-ethyl-1,3-propanediyl]bis(oxy)]-bis[N,N-dicyclohexyl-acetamide], CAS N°: 133338-85-9 Lithium ionophore X: N,N, N’ ,N'-tetracyclohexyl-5,5-dimethyl-3,7-dioxanonanediamide,       or       2,2'-[(2,2-Dimethyl-1,3- propanediyl)bis(oxy)]bis[N,N-dicyclohexylacetamide], ETH 2015, CAS N°: 108444-70-8 Experimental part One volume of organic formulation is brought into contact with one volume of salt water (O / Aext =1), then stirred at 800 rpm at 23°C for 30 minutes. After stopping the stirring, the two phases are left to settle for 5 to 30 minutes at 23°C, after which the aqueous and organic phases are collected. The organic phase was then de-extracted at 80 or 90°C with demineralized water (A / Ode-ext=5) while stirring for 35 minutes at 800 rpm. After stopping stirring, the two phases are left to settle for 10 to 15 minutes at 80 or 90°C, then the two resulting waters are analyzed by ion chromatography. The extraction and de-extraction (regeneration) parameters are shown in Table 2. [Table 2] Parameters Extraction phase Regeneration phase Equipment Dragon SK-0330 Pro Hettich lab technology MKR 13 Hettich lab technology MKR 13 A / 0 ratio A / 0 = 1 A / 0 ~ 5.2 Volumes used A = 1.5 mL A = 5 mL Temperature 22.8°C - RT 91-93.7°C Agitation time 30 min - 1 hour 35 min Stirring speed 500-800 rpm 800 rpm Settling time 5 -30 min 15 min Depending on the equipment available, the orbital shaker plate or the shaker are used for extraction tests. On the other hand, only the shaker is used for regeneration, as it is the only device able to rise in temperature. The results are used after recalculation of the analytical values, corrected for the A / O factor and the washing out (calculated in relation to magnesium). For greater accuracy, only de-extraction measurements are taken into account. Analysis equipment: Metrohm ion chromatography, Cation column: Metrosep C6-150 / 4.0 (ref 6.1051.420) Anion column: Metrosep A supp S 250 / 4.0 (Ref 6.1006.530) The following are some of the definitions needed to characterize the results of the following experimental designs. Extraction yields (Em') and extraction yields (E^), distribution coefficients (Dm ), separation factors (SFua / m)) for the extraction of lithium Li+ in relation to metal Mn+ and the extractant usage rate (%Use(M)) are given by equations (1), (2), (3), (4) and (5) respectively: Em(%) [Mn+]aq—[Mn+]qq x 100 or, x 100 (1) Em(%) x 100 or, ^A^O^de-extX^M ^desext [Mn+]lorg x 100 (2) Dm [Mn+Vorg [Mn+]faq (3) Or $F(Li / M) ~ )Mn+)aq (4) fMn+v %Use(M) = °rgx 100      (5) lCh]Org Where [Mn+]^, IX1*]^, [Mn+lde-ext and [Mn+]^rg respectively represent the initial and final concentrations in the aqueous extraction and de-extraction phases, and in the organic phase for the Mn+ ion. (^ / a) and (0 / a) are the volume ratios between the organic V ' exi         v      de—ext and aqueous phases in the extraction and de-extraction phases respectively. In addition, since a temperature-modulated liquid-liquid extraction solution is being sought, the equilibrium constant Keq (T) will have to be highly dependent on the operating temperature and therefore predominantly enthalpic (AH), as explained by the Arrhenius equation (5). Keq(T) = Kox exp „       (-LH kS\ , = X exp + —) (5) Can be presented in linear form: Ln^Kec / ^ —AG R Experimental design No. 1: Extraction of salts by Lithium ionophores II, IV, V, VIII and X. Duplicate extraction tests were carried out on aqueous solutions of pure LiCl, NaCl, KCl and CaCl2, respectively, in the presence of an excess of MgCl2 for several ionophores using a liquid organic formulation composed of fCEVorg ~ 45 mmol / L of ionophore (Cationic Extractant CE) for 10 equivalents of anionic solvating agent (AS), i.e. 450 mmol / L of N-(3,5-bis(trifluoro-methyl)phenyl)octanamide (C16H19F6NO, CAS N° 1974318-14-3), all dissolved in 1,2-dichlorobenzene (2DCB) (C6H4Cl2, CAS N° 95-501). The aqueous / brine phases to be tested for extraction were created in the laboratory from demineralised water and pure salts (> 99.9%). They are defined in Table 3. [Table 3] Ions Li+ Na+ K+ Ca2+ .. 2+ Mg Cl- Salinity Test 1.1 0.2 mol / L (1388 mg / L) / / / 1.50 mol / L (36.46 g / L) 3.2 mol / L (113 g / L) 151 g / L Test 1.2 / 1 mol / L (23 g / L) / / 1.50 mol / L (36.46 g / L) 4 mol / L (142 g / L) 201 g / L Test 1.3 / / 1 mol / L (39.1 g / L) / 1.50 mol / L (36.46 g / L) 4 mol / L (142 g / L) 217 g / L Test 1.4 / / / 1 mol / L (40 g / L) 1.50 mol / L (36.46 g / L) 5 mol / L (177 g / L) 254 g / L This choice of high salinities and the chloride doping were considered in order to push the extractability of salts by ionophores to their maximum and potentially reduce the uncertainty related to the analysis of de-extracted ions for these products chosen for their potential low capacity to extract Na, K and Ca chloride salts. The extraction and de-extraction protocol previously presented was maintained for each of these tests. The extraction results are given in Table 4. [Table 4] Ionophore Mw (g / mol) Melt point (°C) ICE]^ (mmol / L) AS.eq Density F (kg / L a 20°C) |Li+|forg (mmol / L) |Na|forg (mmol / L) |K+|forg (mmol / L) |Ca2+lforg (mmol / L) %Use (Li) %Use (Na) %Use (K) %Use (Ca) Li II - ETH 1644 394.63 oil 42.9 10 1.283 0.35 1.05 0.25 1.10 0.82% 2.45% 0.58% 2.56% Li IV- ETH 2137 602.93 oil 45.6 10 1.282 8.75 2.45 1.90 7.15 19.2% 5.37% 4.17% 15.7% Li V 176.21 oil 45.6 9.7 1.287 0.10 20.50 6.95 0.35 0.22% 45.0% 15.2% 0.77% Li VIII 798.19 130 45.5 10 1.282 37.75 28.45 0.00 34.55 83,0% 62.6% 0,00% 76,0% Li X-ETH 2015 546.82 oil 44.4 9.9 1.284 6.65 3.15 0.90 5.40 15,0% 7.09% 2.03% 12.2% It appears that the Li VIII tripodant allows much higher extraction of salt than extractants II, IV and X, and that lithium extraction is very low for extractants II and V, which are considered to be lithium ionophores for ion-selective electrodes. These results show that: 1. Just because an ionophore is used in a selective cation exchange electrode does not mean it can also be used in a liquid-liquid salt extraction. For example, the Li II ionophore (ETH 1644) achieves very low salt extraction ranging from 0.25 to 1.10 mmol / L, which is always less than 2.6% of the extractant usage rate. 2. Just because an ionophore is selective for a cation in a selective electrode application does not mean that it will also be selective for that cation in a liquid-liquid extraction. For example, the Li V ionophore, even though it is presented as a lithium ionophore, actually prefers to extract NaCl to a much greater extent than LiCl, with 205 times greater extraction for NaCl. 3. The Li IV and Li X ionophores, which have a very similar structural composition, show similar performances with extractant usage rates for lithium of 19.2% and 15% respectively and for sodium of 5.37% and 7.09% respectively. On the other hand, the Li VIII ionophore had high extractant usage rates of 83%(Li), 62.6%(Na) and 76%(Ca) in the extraction of pure salts. 4. The Li VIII ionophore, which is the 'tripodant' version of the Li IV and Li X ionophores, which are 'dipodant', allows 4.33 times more extractant to be used for LiCl extraction than the latter. Experimental design No. 2: Multi-salt extraction using 14-crown-4 ether-crowns The aim is to carry out multi-salt extraction tests on Li, Na, K, Mg chlorides and CaCl2 with a water composition close to that of continental salt water, i.e. here with an excess of sodium, for several ionophores via a liquid organic formulation composed of [CE]lorg & 80 mmol / L of ionophore (Cationic Extractant CE) for 3 equivalents of anionic solvating agent (AS), i.e. 240 mmol / L of N-(3,4-dichlorophenyl)-octanamide (C14H19Cl2NO, CAS N° 730-25-6), all dissolved in 2-chlorobromobenzene (2CBB) (C6H4BrCl, CAS N° 694-80-4). The brine to be tested for extraction was created in the laboratory from demineralized water and pure salts (> 99.9%). The composition of the water measured (ES-001) is shown in Table 5. [Table 5] Ions Li+ Na+ K+ - 2+ Ca Mg2+ Cl- Salinity Test 2 0.143 mol / L 4.071 mol / L 0.023 mol / L 0.246 mol / L 0.287 mol / L 5.304 mol / L 300 g / L (991 mg / L) (93.64 g / L) (911 mg / L) (9867 mg / L) (6.985 g / L) (188 g / L) It is representative of a brine leaving the well for the implementation of a direct lithium extraction (DLE) solution, or rather, direct lithium salt extraction (DLSE). The extraction and de-extraction protocol previously presented is maintained. Given the level of extraction of Li V, based on an ether crown, we focused the study on 14-crown-4 based ether crowns. In addition to Li VI and Li VII, the two ionophores below were tested and also characterised in lithium-selective electrodes. Dibenzo-14-crown-4 (DB14C4), CAS N°: 14174-06-2 6-[2-(benzyloxy)ethyl]-6-dodecyl-14-crown-4 (BzO Li VII), CAS N°: 106868-24-0 The results are summarized in Table 6. Ionophore Mw (g / mol) Melt point (°C) Density F (kg / L a 20°C) [Li+]forg (mmol / L) [Na+]fors (mmol / L' Li VI 384.51 94 1.585 1.80 1.37 Li VII 552.72 oil 1.574 0.91 0.93 DB14C4 300.35 146 1.591 1.02 3.67 BzO Li VIII 506.75 oil 1.573 1.64 0.97 Li VIII 798.19 130 1.572 36.30 9.37 [Table 6] [K+]forg (mmol / L) (mmol / L) [Ca2+]forg (mmol / L) SF (Li / Na) SF (Li / K) SF (Li / Mg) SF (Li / Ca) 0.00 0.00 0.00 36.10 inf. inf. inf. 0.00 0.00 0.00 27.41 inf. inf. inf. 0.00 0.00 0.00 7.94 inf. inf. inf. 0.00 0.00 0.00 47.23 inf. inf. inf. 0.18 0.00 0.00 153 469 inf. inf. It appears that the four ionophores based on 14-crown-4 ether-crowns only achieve very modest LiCl extraction with less than 2.25% extractant usage (or loading) with less than 1.8 mmol / L of LiCl extracted for a formulation with 80 mmol / L extractant (EC). On the other hand, the Li VIII ionophore confirmed its effectiveness with a 45.4% usage rate (or loading) of the extractant with 36.30 mmol / L of LiCl absorbed by this formulation. In addition, the separation factors (SF) were very good, with 'infinite' values for Li / Mg and Li / Ca, 469 for Li / K and 153 for Li / Na. In synthesis, it appears that in a single contact at a ratio (O / A)ext = 1, 28.5% of the lithium and less than 5% of the other ions are extracted with Li VIII on a liquid-liquid extraction stage, as shown in Table 7 from analyses of the composition of the treated brine. [Table 7] (O / A)ext= 1 Li+ Na+ K+ Mg2+ Ca2+ cr Brine to de treated (mmol / L) 142.8 4071.2 246.2 287.4 23.3 5081.6 Treated brine (mmol / L) 102.1 4032.1 238.0 274.3 23.2 4967.1 EMn+(%) 28.5% 1,0% 3.3% 4.6% 0.5% 2.3% SF(Li / Mn+) / 153 469 Inf. Inf. / If an ion balance is carried out using the composition of the formulation de-extracted at 80°C in five volumes of demineralized water, the result is even more favourable with regard to the impurities Na+, K+, Mg2+ and Ca2+, which are then practically not extracted, while retaining 25.4% of extracted lithium, as can be seen in Table 8. [Table 8] (O / A)ext=l Li+ Na+ K+ Mg2+ Ca2+ cr Brine to de treated (mmol / L) 142.8 4071.2 246.2 287.4 23.3 5081.6 Treated brine (mmol / L) 106.5 4061.8 246.0 287.4 23.3 5081.6 EMn+(%) 25.4% 0.2% 0.1% 0.0% 0.0% 0.0% SF(Li / Mn+) / 148 465 Inf. Inf. / Note the strong competition between Li+ and Ca2+ for the extractant since experimental design No. 1 had 34.55 mmol / L of CaCl2 absorbed alone whereas this assay did not see any absorption of CaCl2 in the presence of lithium. Another potential reason may be due to an eq.AS here of 3 instead of 10 for the previous experiment. As experimental designs 1 and 2 were carried out with 10 and 3 equivalents of anionic solvating agent AS respectively, we looked at the impact of this parameter on the extraction capacity in LiCl, NaCl and CaCl2 of a 80 mmol / L formulation of Li VIII ionophore in order to increase the usage rate of the extractant. Experimental design No. 3: Extractions and stoichiometric Cl solvation coefficient- Extraction tests were carried out on aqueous solutions of LiCl, NaCl and CaCl2 , as pure body, in duplicate, in the presence of an excess of MgCl2 , for 4 liquid organic formulations composed of [CE]lorg ~ 80 mmol / L of Li VIII ionophore for 1, 3, 5 and 10 equivalents of anionic solvating agent (AS) respectively, i.e. 80, 240, 400 and 800 mmol / L of N-(3,5-bis(trifluoromethyl)-phenyl)octanamide, all dissolved in 1,2-dichlorobenzene (2DCB). The various aqueous phases and brines to be tested for extraction were created in the laboratory from demineralized water and pure salts (> 99.9%). Their compositions are shown in Table 9. [Table 9] Ions Li+ Na+ Ca2+ Mg2+ Cl Salinity Test 3.1 0.165 mol / L (1150 mg / L) / / 1.62 mol / L (39.36 g / L) 3.405 mol / L (120.7 g / L) 161.2 g / L Test 3.2 / 0.201 mol / L (4639 mg / L) / 1.59 mol / L (36.59 g / L) 3.377 mol / L (119.7 g / L) 163 g / L Test 3.3 / / 0.205 mol / L (8251 mg / L) 1.62 mol / L (39.36 g / L) 3.605 mol / L (129.4 g / L) 177 g / L The extraction and de-extraction protocol previously presented was maintained for each of these tests. The results are summarized in Tables 10 to 13 and Figures 2 and 3. [Table 10] lons / CE Use Eq.SA=l Eq.SA = 3 Eq.SA = 5 Eq.SA= 10 Keq Test 3.1 ELi(%) / %Use(Li) 7.4% / 15.4% 26% / 53.8% 36.7% / 75.9% 42.5% / 88.1% 59.060 Test 3.2 ENa(%) / %Use(Na) 1.0% / 2.4% 3.2% / 8.1% 6.4% / 16.0% 10.9% / 27.4% 0.859 Test 3.3 ECa(%) / %Use(Ca) 0.2% / 0.5% 2.3% / 5.9% 6.3% / 16.3% 9.9% / 25.5% 0.366 Eq.SA [SA]^ (mmol / L) Density F (kg / L a 20°C) [Li+]forg (mmol / L) [Li+]forg (mmol / L) [Mg2+]forg (mmol / L) 1 80 1.284 12.305 12.136 0 3 240 1.281 43.03 43.33 0 5 400 1.278 60.75 60.86 0 10 800 1.271 70.481 70.916 0 [Table 11] [Mg2+]forg (mmol / L) DLi SF (Li / Mg) Recovery Li (%) CEUse (%) Log(Keq) Keq(Li) 0 0.080 Infinite 7.4% 15.4% 1.7 50.7 0 0.351 Infinite 26,0% 53.8% 1.82 66.7 0 0.579 Infinite 36.7% 75.9% 1.89 77.1 0 0.740 Infinite 42.5% 88.1% 1.67 46.3 Eq.SA [SA]^ (mmol / L) Density F (kg / L a 20°C) [Na+]forg (mmol / L) [Na+]forg (mmol / L) [Mg2+]forg (mmol / L) 1 80 1.284 1.94 2.12 0 3 240 1.281 6.52 6.23 0 5 400 1.278 12.82 12.67 0 10 800 1.271 21.89 21.95 0 [Table 12] [Mg2+]forg (mmol / L) DNa SF (Na / Mg) Recovery Na (%) CEUse (%) Log(Keq) Keq(Na) 0 0.010 Infinite 1.0% 2.4% -0.088 0.82 0 0.033 Infinite 3.2% 8.1% -0.102 0.79 0 0.068 Infinite 6.4% 16.0% -0.019 0.96 0 0.122 Infinite 10.9% 27.4% -0.069 0.85 [Table 13] Eq.SA [SAJ^g (mmol / L) Density F (kg / L a 20°C) [Ca2+]forg (mmol / L) [Ca2+]forg (mmol / L) [Mg2+]f01 (mmol / L’ 1 80 1.284 0.38 0.38 0 3 240 1.281 4.69 4.64 0 5 400 1.278 13.03 13.20 0 10 800 1.271 20.42 20.48 0 g [Mg2+]forg (mmol / L) Dns SF (Ca / Mg) Recovery Ca (%) CEUse (%) Log(Keq) Keq(Ca) 0 0.002 Infinite 0.2% 0.5% -0.545 0.29           £ 0 0.023 Infinite 2.3% 5.9% -0.348 0.45 0 0.068 Infinite 6.3% 16.3% -0.254 0.56 0 0.110 Infinite 9.9% 25.5% -0.606 0.25 It appears that the anionic solvating agent AS does indeed play its role as a facilitator of salt transfer to the organic phase, as the quantity of LiCl, NaCl or CaCl2 extracted increases with eq.SA. Thus, the extraction yield (Figure 2) and the extractant usage rate (Figure 3) increase with eq.SA, but a large difference in performance is observed at equilibrium between trial 3.1 and trials 3.2 and 3.3, showing a significant selectivity for lithium. It appears that the very high selectivity of the Li VIII ionophore enables the same level of lithium extraction performance to be achieved overall, with or without the presence of sodium, compared with experiments 1 and 2. From the data in these tables and figures, it is clear that the equilibrium constants Keq are very different (Trials 3.1 / 3.2: 68 / 1 and Trials 3.1 / 3.3: 161 / 1). The proposed formulation is therefore well suited to the selective extraction of LiCl in the presence of NaCl and / or CaCl2 due to the large difference in equilibrium constants Keq and the non-extraction of magnesium and potassium ions. Experimental design No. 4: Influence of the O / A ratioext on the extraction of salts. Extraction tests were carried out on a multi-salt brine with O / Aext increasing from 0.1 to 10, for a liquid organic formulation with 3 equivalents of anionic solvating agent (AS), i.e. N-(3,4-dichlorophenyl)-octanamide (C14H19Cl2NO, CAS N° 73025-6) for, [CE]lorg = 0.3 mol / L of Li VIII ionophore, dissolved in 2-chlorobromobenzene (2CBB) (C6H4BrCl, CAS N° 694-80-4). The brine to be tested in extraction, representative of a real lithium-rich brine, with the presence of the sulphate ion, was created in the laboratory from demineralized water and pure salts (> 99.9%). Its salinity is 425 g / L and its composition is shown in Table 14. [Table 14] Ions Li+ Na+ K+ Ca2+ Mg2+ Cl SO42 Test 4 0.415 mol / L 4.059 mol / L 1.166 mol / L 0.021mol / L 0.820 mol / L 7.06 mol / L 0.132 mol / L (2883 mg / L) (93.30 g / L) (45.60 g / L) (845 mg / L) (19.92 g / L) (250.2 g / L) (12.7 g / L) The O / Aext tested were 0.1; 0.25; 0.5; 1; 2; 4 and 10. These tests were used to assess the influence of this ratio on the extraction yields of the various ions. The extraction and de-extraction protocol previously presented is maintained for each of these tests with the exception of the O / Aext given above. The results are summarized in Tables 15 to 17 and Figure 4. [Table 15] (O / A)ext 0.1 0.25 0.5 1 2 4 10 Eu{%) 10.1% 20.1% 34.6% 58.7% 78,0% 94,0% 98.1% EU%) 0.0% 0.1% 0.2% 0.5% 1.8% 6.9% 20.7% Ek(%) 0.0% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% Eca(%) 0.5% 1.2% 2.6% 6.5% 14.8% 39.6% 72.6% EMg(%) 0.0% 0.00% 0.01% 0.01% 0.03% 0.09% 0.08% EsO4(%) 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% Note the total absence of extraction for the K+, Mg2+ and SO42-ions. [Table 16] (O / A)ext [Lifaq (mol / L) [Na+]faq (mol / L) [K+]faq (mol / L) [Ca2+]faq (mol / L) [Mg2+]faq (mol / L) [so42-]faq (mol / L) [ci-]faq (mol / L) 0 0.415 4.059 1.166 0.021 0.820 0.132 7.058 0.1 0.374 4.058 1.166 0.021 0.820 0.132 7.014 0.25 0.332 4.056 1.166 0.021 0.820 0.132 6.970 0.5 0.272 4.051 1.166 0.021 0.820 0.132 6.905 1 0.172 4.038 1.166 0.020 0.820 0.132 6.789 2 0.091 3.986 1.166 0.018 0.819 0.132 6.653 4 0.025 3.779 1.166 0.013 0.819 0.133 6.368 10 0.008 3.218 1.166 0.006 0.819 0.133 5.776 [Table 17] (O / A)ext SF(Li / Na) SF(Li / K) SF(Li / Ca) SF(Li / Mg) SF(Li / SO4) 0.1 375 Infinity 22 5 254 Infinity 0.25 309 Infinity 22 16 561 Infinity 0.5 270 Infinity 19 4 203 Infinity 1 266 Infinity 20 17 425 Infinity 2 192 Infinity 20 10 609 Infinity 4 212 Infinity 24 16 973 Infinity 10 201 Infinity 20 69 144 Infinity These experiments demonstrate the suitability of the formulation tested for selective extraction of LiCl in the presence of other alkali and alkaline-earth salts. 10 From these data, Figure 5 also shows a LiCl distribution curve between the organic and aqueous phases at constant temperature and pressure, which we call the LiCl absorption isotherm at 20°C for the excess chloride concentration studied. 15 Experimental design No. 5: Calorimetric measurements in methanol at 25°C In order to validate the complexation capacity of the Li VIII ionophore for these cations Li+, Ca2+ and Na+, an isothermal calorimetric titration (ITC) study of their complexation was carried out. The experiments were carried out on an ITC200 (GE Healthcare) and a TAM 2277 (TA Instruments) at room temperature. The analysis solvent was methanol (Chromasolv®, Sigma-Aldrich) and the ionic strength was set at 0.1M using Et4NCl. Stock solutions of Li (0.1232 mo / L), Ca (0.1300 mol / L) and Na (0.1074 mol / L) were prepared from chloride salts and their concentrations were determined by ICP analysis. On the ITC200, each titration consisted of 26 additions of 1.5]jL of metal stock solution to the 0.2022 mL analysis cell containing the Li VIII ionophore ligand under stirring. On the TAM 2277, each titration consisted of 17 additions of 15 pL of metal stock solution to the 1mL analysis cell containing 0.8 mL of solution incorporating the Li VIII ionophore ligand under stirring. For each study, several titrations were carried out to determine the best conditions for analysis, then replicates (at least 3) were carried out. The ionophore extractants CE00 (Li VIII) and CE40 form complexes with a 1:1 stoichiometry (Mn+:CE, Mn+ = Li+, Na+ or Ca2+). The complexation equilibrium and associated complexation constant in methanol (KMeOH) are defined as follows: Mn+ + CE <==> MCE, KMeOH = [MCE] / [M][CE] (M = Li, Na or Ca and CE= Li VIII= CE00 or CE40) The averages of the results obtained for cationic extractants CE00 and CE40 are given in Table 18. [Table 18] Extractant Ions Log KMe0H AGa (kJ / mol) AH (kJ / mol) -TASb (kJ / mol) |AH / (TAS)| CEOO Li+ 2.2 + / - 0.2 -12.6 -14.7 2.1 7.0 Ca2+ 4.9 + / - 0.2 -28.0 -26.0 -2.0 13.0 Na+ 0.9 + / - 0.3 -5.1 Not measurable / / CE40 Li+ 1.7 + / - 0.2 -9.9 -12 4.3 2.8 a Calculated from the relationship AG = -RT ln(K) (T= 298K, R=8.314 J / mol / K) b Calculated from the relationship AG = AH - TAS (T= 298K). The heat of reaction could not be determined for NaCl with the equipment used because complexation was too low. These thermodynamic parameters (AH, AS) indicate an exothermic complexation reaction for lithium and calcium with a negative enthalpy component AH which dominates in the calculation of the free enthalpy AG, with for example here, at temperature T=298K, a ratio |AH / (TAS)| of 7 and 2.8, respectively, for lithium complexation. It follows that the ability of the ionophores CE00 and CE40 to complex these cations is highly temperature dependent. Hot water extraction was therefore considered. Experimental design No. 6: De-extracting a salt-loaded formulation at 80°C For a liquid organic formulation composed of [CE]^ = 0.3 mol / L of Li VIII ionophore and 3 equivalents of anionic solvating agent (AS), i.e. 0.9 mol / L N-(3,4-dichlorophenyl)-octanamide (C14H19Cl2NO, CAS N° 730-25-6), all dissolved in 2-chlorobromobenzene (2CBB) (C6H4BrCl, CAS N° 694-80-4), extraction was carried out at 23°C on a multi-salt brine, then the de-extraction of the previously absorbed salts was assessed by contact with demineralized water at 80°C for increasing A / Ode-ext ranging from 0.02 to 5. The brine used for extraction, which is representative of a real lithium-rich brine, was created in the laboratory from demineralized water and pure salts (> 99.9%). After analysis, its salinity is 360 g / L and its composition is shown in Table 19. [Table 19] Ions Li+ Na+ K+ Ca2+ .. 2+ Mg cr so42 Test 6 0.373 mol / L 3.413 mol / L 0.997 mol / L 0.012mol / L 0.689 mol / L 5.93 mol / L 0.128 mol / L (2585 mg / L) (78.46 g / L) (38.99 g / L) (475 mg / L) (16.75 g / L) (210.2 g / L) (12.3 g / L) The A / Ode-ext tested at 80°C were 0.02; 0.033; 0.05; 0.067; 0.1;  0.2;  0.5 and 5. These tests enable us to assess the influence of this ratio, and therefore of the quantity of demineralized water used, on the de-extraction yields of the various ions. The extraction and de-extraction protocol previously presented is maintained for each of these tests with the exception of the A / Ode-ext given above and the O / Aext given below. Firstly, a single contact extraction was carried out at a ratio (O / A)ext = 1.43 with 95 mL of organic phase and 66.5 mL of brine. The liquid-liquid extraction performance is illustrated in Table 20 using analyses of the composition of the treated brine. [Table 20] (O / A)ext = 1.43 Li+ Na+ K+ Ca2+ Mg2+ Cl so42 Brine to de treated (mmol / L) 372.5 3 413 997.1 11.8 689.1 5 928 128.2 Treated brine (mmol / L) 114.4 3 351 995.2 10.9 687.6 5 601 128.2 Emh+(%) 69.3% 1.8% 0.2% 8,0% 0.2% 5.5% 0.0% SF(Li / Mn+) / 174 2 453 13.1 2 450 174 / If an ion balance is carried out using the composition of the formulation de-extracted at 80°C in 5 volumes of demineralized water, the result is more favourable with regard to the extraction of lithium, which rises from 69.3% to 74.5%, while the impurities remain very poorly extractable, except for calcium, in a very low initial concentration, as shown in Table 21. [Table 21] (O / A)ext = 1.43 Li+ Na+ K+ Ca2+ Mg2+ Cl so42 Brine to de treated (mmol / L) 372.5 3 413 997.1 11.8 689.1 5 928 128.2 Treated brine (mmol / L) 95.0 3 366 996.2 9.8 688.4 5 597 128.1 Emh+(%) 74.5% 1.4% 0.1% 17.0% 0.1% 5.6% 0.1% SF(Li / Mn+) / 210 2 958 14.3 2 955 210 / These balances indicate the formulation's ability to provide an initial effective separation of lithium from the other ions. The results of de-extraction with demineralized water at 80°C are summarized in Tables 22 and 23 and Figures 6 and 7. |Table 22] (0 / A) de-extraction [Li ] org (mol / L) [Na+]forg (mol / L) [K]forg (mol / L) [Ca2+]forg (mol / L) [Mg2+]forg (mol / L) [cr]forg (mol / L) [SO42+]forg (mol / L) 0 194 32.8 0.69 1.41 0.476 231 0.10 0.02 157 4.0 0.00 0.57 0.033 162 0.04 0.033 132 2.5 0.00 0.25 0.000 135 0.03 0.05 110 1.8 0.00 0.24 0.000 112 0.03 0.067 96 1.7 0.08 0.12 0.017 98 0.02 0.1 81 1.5 0.06 0.09 0.026 83 0.02 0.2 45 1.3 0.06 0.06 0.032 47 0.01 0.5 21 1.2 0.06 0.05 0.021 22 0.01 [Table 23] (A / O)de-ext 0.02 0.033 0.05 0.067 0.1 0.2 0.5 5 E'LI(%) 19.3% 31.9% 43.3% 50.5% 58.2% 76.6% 89.2% 100% E'Na(%) 87.7% 92.4% 94.4% 94.7% 95.5% 95.9% 96.4% 100% E'k(%) 100% 100% 100% 88.4%* 91.5%* 91.4%* 90.6%* 100% E'Ca(%) 59.4% 82,0% 82.7% 91.2% 93.7% 95.6% 96.2% 100% E'Mg(%) 93.1% 100% 100% 96.4%* 94.5%* 93.2%* 95.6%* 100% E'sO4(%) 57.8% 65.5% 72.1% 76.3% 80.2% 84.9% 90.7% 100% *Within the limits of analysis precision. Based on these results, Figure 8 also shows a curve for the distribution of LiCl between the organic and aqueous phases at constant temperature and pressure, which we call the isotherm for the de-extraction of LiCl with demineralized water at 80°C. By combining Figures 5 and 8, Figure 9 shows two lithium partition curves at 20°C and 80°C for the LiCl separation and purification process. The difference between these isotherms expresses the possible respiration of the formulation for the implementation of the temperature-modulated LiCl liquid-liquid extraction process. These LiCl partition isotherms can be used to construct the associated McCabe-Thiele to determine the required number of unit stages to be implemented in both the extraction and deextraction phases for two given operating lines, as illustrated in Figure 10. Design of experiment no. 7: Extractability of nitrate salts, other di-ionic salts, LiNO3, NaNO3 and tri-ionic salt Ca(NO3)2 . The aim is to carry out extraction tests on aqueous solutions of LiNO3, NaNO3 and Ca(NO3)2 as pure bodies, for variable concentrations, in the presence or not of an excess of Mg(NO3)2 , for a liquid organic formulation composed of [CE^rg * 250 mmol / L of Li VIII ionophore for 3 equivalents of anionic solvating agent (AS), i.e. 750 mmol / L of N-(3,4-dichlorophenyl)-octanamide (C14H19Cl2NO, CAS N° 730-25-6), all dissolved in 2-chlorobromobenzene (2CBB) (C6H4BrCl, CAS N° 694-80-4). The various aqueous phases and brines to be tested for extraction were created in the laboratory from demineralized water and pure salts (> 99.9%). Their compositions are shown in Table 24. [Table 24] Ions Li+ Na+ Ca2+ Mg2+ no3 Salinity Test 7.01 0.006 mol / L / / / 0.006 mol / L 0.434 g / L Test 7.02 0.090 mol / L / / / 0.090 mol / L 6.230 g / L Test 7.03 0.494 mol / L / / / 0.494 mol / L 34.04 g / L Test 7.04 0.977 mol / L / / / 0.977 mol / L 67.36 g / L Test 7.05 1.990 mol / L / / / 1.990 mol / L 137.2 g / L Test 7.06 0.087 mol / L / / 1.5 mol / L 3.087 mol / L 228.4 g / L Test 7.07 0.478 mol / L / / 1.5 mol / L 3.478 mol / L 255.4 g / L Test 7.08 0.969 mol / L / / 1.5 mol / L 3.969 mol / L 289.2 g / L Test 7.09 1.937 mol / L / / 1.5 mol / L 4.937 mol / L 356.0 g / L Test 7.11 / 0.015 mol / L / / 0.015 mol / L 1.277 g / L Test 7.12 / 0.093 mol / L / / 0.093 mol / L 7.952 g / L Test 7.13 / 0.484 mol / L / / 0.484 mol / L 41.18 g / L Test 7.14 / 0.971 mol / L / / 0.971 mol / L 82.57 g / L Test 7.15 / 2.020 mol / L / / 2.020 mol / L 171.7 g / L Test 7.16 / 0.102 mol / L / 1.5 mol / L 3.102 mol / L 231.1 g / L Test 7.17 / 0.521 mol / L / 1.5 mol / L 3.521 mol / L 266.7 g / L Test 7.18 / 1.027 mol / L / 1.5 mol / L 4.027 mol / L 309.7 g / L Test 7.19 / 2.024 mol / L / 1.5 mol / L 5.024 mol / L 394.5 g / L Test 7.21 / / 0.109 mol / L 1.5 mol / L 3.218 mol / L 240.4 g / L Test 7.22 / / 0.511 mol / L 1.5 mol / L 4.022 mol / L 306.2 g / L Test 7.23 / / 1.010 mol / L 1.5 mol / L 5.020 mol / L 388.1 g / L Test 7.24 / / 1.992 mol / L 1.5 mol / L 6.984 mol / L 549.3 g / L The extraction and de-extraction protocol previously 5 presented was maintained for each of these tests. For a contact at 20°C with (O / A)ext = 1, for each of these initial water compositions, five distribution isotherms were obtained at 20°C representing the relative concentrations of the 10 different salts between the organic extract and the aqueous phases at equilibrium, as shown in Figure 11. It appears that saturation of the 0.25 mol / L formulation is rapidly reached for the LiNO3 and Ca(NO3)2 doped salts, while NaNO3 is only slightly absorbed. This shows that, as with chloride salts, di-ionic nitrate salts are also extractable. Design of experiment no. 8: Evolution of density and viscosity of formulations with Li VIII The aim was to assess the impact of relative concentrations of cationic extractant and anionic solvating agent on the density and viscosity at 20°C of the formulation. To do this, different formulations with Li VIII, N-(3,4-dichlorophenyl)-octanamide, all dissolved in 2-chlorobromobenzene (2CBB), were carried out for different relative concentrations of CE and AS. The results obtained are summarized in Figures 12 and 13. It appears that the density decreases linearly with the CE concentration at iso equivalence AS. We also note that for the treatment of brines with a density of 1.22 kg / L, it is not possible to go beyond a certain CE concentration if, for example, the formulation has to remain with a density greater than 1.27 kg / L. It appears that the viscosity of the formulation with increasing concentrations of this Li VIII extractant can become limiting for its industrial use in these liquid-liquid extraction systems, in particular those using gravity decanters where decantation is all the more difficult as the continuous phase is viscous. We therefore looked at other compounds in order to identify extractants that maintain good selectivity and extraction for lithium while generating less viscosity. In particular, liquid extractants are interesting to study because they are potentially more soluble and generate less formulation viscosity. Compounds of formula: The compounds of interest are synthesized in three successive stages. Stage 1: Synthesis of the secondary amine Place the ketone (10 mmol, 1 eq), solvent (17 Vol), amine (45 mmol, 4.5 eq) and reagent(s) in a clean, dry flask. Depending on the reagent, heat if necessary. The conversion is followed by TLC with the disappearance of the initial ketone. Evaporation of the solvent (and sometimes the residual amine) under reduced pressure. Filtration if necessary over Fontainebleau sand then addition of methanol (12 Vol). Addition by portions of NaBH4 (30 mmol, 3 eq) if necessary, stirring for 1-15 h at RT. Purification on silica gel if necessary. (DCM to DCM / ethyl acetate). Yield: 20-77%. Stage 2: Synthesis of chloroacetamide Place the amine formed previously (10 mmol, 1 eq), dichloromethane (3 Vol, 15 eq) and triethylamine (30 mmol, 3 eq) in a flask. Add chloroacetyl chloride (20-25 mmol, 2-2.5 eq) cold under an argon atmosphere. Shake at room temperature for 5-24 h. Add 2 volumes of water and carry out 2 counterextractions of the aqueous phase with 2 volumes of DCM. Concentrate the organic phase in a rotary evaporator. Purification of the product on a silica gel column (100% DCM eluent). Yield: 30-70 Stage 3: Synthesis of the compound of interest In a tricol, add NaH (3.5-4 eq) to 10 Volumes of anhydrous THF. Heat the medium to reflux under argon. Hot introduction of the triol solubilized in 10 Vol of THF followed by the synthesized chloroacetamide, solubilized in 15-20 Vol of THF. Stir the medium under reflux for 1-24h. Neutralize the medium by adding 10 Volumes of water. Carry out two counter-extractions of the aqueous phase with 5 Volumes of DCM. Then wash the organic phase one or two times with 5 V of water. Concentrate the organic phase in a rotary evaporator. Purify the crude obtained by chromatography on silica gel (eluent: heptane / ethyl acetate). Yields are generally between 50-70%. 5 Table 25 shows the formulae of the compounds synthesized, Li VIII being renamed CE00. [Table 25] / ---\     CH3 AA /      O \ / —N 0— / 0—\ / — \ x\ ■ O Z : • ar 1           W °\ XX XX x° / k o AT o Ax ° »7 ar ar 9 Q ax qx AX 6 CE00 (133338-85-9) CE01 CE02 H3C--\ 0-¾ A \-- /   \-- /   O       / ^N o 3 ch3 / —\   y— /   o       / >—n CxCr c _ : / \- xr° XX a^ CE03 CE04 CE05 p o 0Jy\ Q ,—\ y—o    \—n AAA H              / ---\ _ xOrOoNP <r Cob AN~ - \ / —N 0— / / 0—\ / —x x   ° x\ o         ) o    Y x °y yy Oo N-- / CE06 CE07 CE08 CP C°Pro CJ ^_Zn / x— / °' \ n-A' c ch3 Y> A o '--'   \-- /   O      \—N o / z      ) <a oCH3 °X OA N—(   > CH3 arC"rA °y a' CE09 CE10 (133338-84-8) CE11 A,0 A A ar-lA0 ’ b V <b b <b CE12 CE13 CE14 b S . \  ^1    II         / \ / ° JL A\ / /     \ /   IT L J o          ( -' b - CE15 CE16 CE17 \        0 |—^\ _. N                           /                 II J J if ° ' yb 0 Jk bb^ / d- 1 o Y     \___ o \ __   .**          / X /          II      J \ / A" Yr "a 'A \ । II                / _                 n ' X—°       \ * A o $ X : n / **y          o'"        .o    A A6 ^b CE18 CE19 CE20 ch3      ch3 r c h3c—v   2—ch3 / ya     H3C\ / CH3 2—n   o—' / o—<   2— H3C    \--'    O      \—N 3 / / \ / / \ o           /     0     / CH3 0=( ch3 ( h3c    n—(       ch3 \—(  ^ch3 ch3 9£H £no         / eH0^_ <tV \ X----<      >---0 2 '---0      M---'      0£H H— /     O   \-- / J V" £H0--'        / --H £H0 £ho CHj          CHj H,C---\ / \ >---N        CHj / HjC                    y---\    t                    CHj \ / --° \ °--\ / --- H3C       N---Z           CHj         A---N       CHj O  Q y— CHj                HjC--< HjC                                        CHj CE21 CE22 (148303-04-2) CE23 (746656-32-6) ch3 0          0—\   ^13 /      °\ A \ h13c6-N\          2      0     c6h13 C6H13 zn-c6h13 H13C6 ch3 o    0—\0 .    ^sH,? / -o      / ^N Hi7c8-N\           \      o Xc8h17 c8h17 zn-c8h17 Hi7C8 ch3 o / °^A / c,oH21 /      °\ An\ H21C10-N             /      0     c10h21 CwH2i zn-c10h21 H21C10 CE24 CE25 CE26 '—z              1 A\ / / / A 0        0----f / ---0        0 0         '----- cj ryA 9n A\ / / 0      °——\ / --0      0 aL -=^ CE27 CE28 CE29 ch3 / / °\ AN^) 0         > o x—7 o=( V) ^cna /    X              _X        0 \            X^xJ        xx, A'~~ A ° / x / ^A * 0         0                     x. / ■""""A                      -CHi /   x                     O \ Ax           o / A- / A x^.^ / ^rX ° X"^xA       n    \ o'     k / x°              A---7 CE30 (405264-17-7) CE31 CE32 ch3 zAV_ / CH3 _A \= / \— / o    Vnz °Ab N—CHo     ^=7 A 9 ^CH3 ^CHj ch3 0     O     / O \      / AH-13 °\ A\ H3C-"nx           )     0      CH3 ^6^13 °=\ n-c6h13 h3c CE33 (405264-15-5) CE34 (405264-16-6) CE35 A /            CH, «■      h / ch3 0 o^P / Csh17 / — /   0      —N\ H3C-"N^          5     0      CH3 c8h17 0=(^ n-c8h17 h3c ch3 0 o—-^d^ch3 / —    0     A—N' / N           \     0     --CH3 h3A )   0={ H3C             N \ < a3 ch3 CE36 (61183-76-4) CE37 CE38 ch3 o o--- / ) 0---<       ,----\ A7 \ 3^^° o A A \ ° । .          N                              /                   II            / iA^       / A / ’A A\ । II                  / ° \ o / A A ' : ' 9 . 9 CE39 CE40 CE41 r            xx ° । _N                         / II / 'd II                     / ° \ 0 yd v rv^ 0       0---\   .---0       0 o    V-- CE42 CE43 Tables 26 and 27 show the characteristics of the compounds synthesised. Code N° CE Simplified Name Raw Formula CAS N° Mw (g / mol) Melt Point RI R2 R3 R4 R5 R6 CEOO Ethyl-N(CyHex)2 C48H83N3O6 133338-85-9 798.19 130°C Cyclohexyl Cyclohexyl Ethyl H H H CEO1 Methyl-N(CyHex)2 C47H81N3O6 Unknown 784.16 90°C Cyclohexyl Cyclohexyl Methyl H H H CE02 i-Prop-N( CyHex) 2 C49H85N3O6 Unknown 812.23 176°C Cyclohexyl Cyclohexyl Iso-Propyl H H H CEO3 n- B utyl -OC- N (CyHex) 2 C51H89N3O7 Unknown 856.27 142°C CycloHexyl CycloHexyl MeOButyl H H H CE04 l-Me-Et-N(CyHex)2 C49H85N3O6 Unknown 812.22 75°C Cyclohexyl Cyclohexyl Ethyl Methyl H H CE05 CyHex-N( CyHex) 2 C52H89N3O6 Unknown 852.28 89.5°C CycloHexyl CycloHexyl CycloHexyl H H H CE06 PhCOC-N(CyHex)2 C54H87N3O7 Unknown 890.28 196.5 CycloHexyl CycloHexyl MeOBenzyl H H H CE07 H-N(CyHex)2 C46H79N3O6 Unknown 770.14 167°C CycloHexyl CycloHexyl H H H H CE08 Ethyl-N(CyOct)2 C60H107N3O6 Unknown 966.53 oil CycloOctyl CycloOctyl Ethyl H H H CE09 Ethyl-N(CyOct,t-But) C48H89N3O6 Unknown 804.24 oil CycloOctyl tert-Butyl Ethyl H H H CE1O Ethyl-N (CyHex,Et) C36H65N3O6 133338-84-8 635.92 oil CycloHexyl Ethyl Ethyl H H H CE11 Ethyl-N(CyHex, iProp) C39H71N3O6 Unknown 677.99 oil Cyclohexyl Iso-propyl Ethyl H H H CE12 i-Prop-N(CyHexJ-Prop) C42H77N3O6 Unknown 720.08 oil Cyclohexyl Iso-propyl Iso-propyl H H H CE13 Ethyl-N (CyHex, i-But) C42H77N3O6 Unknown 720.08 oil Cyclohexyl Iso-butyl Ethyl H H H CE14 i-Prop-N(CyHex,i-But) C43H79N3O6 Unknown 734.12 oil Cyclohexyl Iso-butyl Iso-propyl H H H CE15 i-But-N(CyHex,i-But) C44H81N3O6 Unknown 748.14 oil Cyclohexyl Iso-butyl Iso-Butyl H H H CE16 Ethyl-N(CyHex,t-But) C42H77N3O6 Unknown 720.08 oil Cyclohexyl tert-Butyl Ethyl H H H CE17 i-Prop-N(CyHex,t-But) C43H79N3O6 Unknown 734.12 oil Cyclohexyl tert-Butyl Iso-propyl H H H CE18 Ethyl-N (CyPen,i-Prop) C36H65N3O6 Unknown 635.93 oil Cyclopentyl Iso-propyl Ethyl H H H CE19 i-Prop-N(CyPen,i-Prop) C37H67N3O6 Unknown 649.96 oil Cyclopentyl Iso-propyl Iso-propyl H H H CE20 i-Prop-N(CyPen)2 C43H73N3O6 Unknown 728.07 95°C Cyclopentyl Cyclopentyl Iso-propyl H H H CE21 Ethyl-N(s-But)2 C36H71N3O6 Unknown 641.95 oil Sec-butyl Sec-butyl Ethyl H H H CE22 Ethyl-N(n-But)2 C36H71N3O6 148303-04-2 641.95 oil n-butyl n-butyl Ethyl H H H CE23 Ethyl-N(i-But)2 C36H71N3O6 746656-32-6 641.95 oil i-Butyl i-Butyl Ethyl H H H CE24 Ethyl-N(n-Hex)2 C48H95N3O6 Unknown 810.26 oil n-Hexyl n-Hexyl Ethyl H H H CE25 Ethyl-N(n-Oct)2 C60H119N3O6 Unknown 978.60 oil n-Octyl n-Octyl Ethyl H H H [Table 26] [Table 27] (Me = Methyl) X X Methyl | X X X X X X X X X X X in ce X X Methyl | Methyl | X X X X X X X X X X S X X | Methyl | | Methyl | X X X X X X X X X X co cc | Ethyl | Ethyl | Ethyl | | Ethyl | | Ethyl | | Ethy | | Ethy | | Ethyl | | Ethyl | | Ethyl | Ethyl | Ethyl | Ethyl | Ethyl | CM CC n-decyl | 2-Ethyl- Hexyl CycloHexyl | CycloHexyl | |           Piperidine          | |         Azepane          | |          Azocan          | Methyl | | Ethyl | Methyl | Methyl Methyl | Ethyl |        Morpholine        | ce | n-decyl | 2-Ethyl-Hexyl | CycloHexyl | | CycloHexyl | | Phenyl | | Phenyl | |   n-Hexyl    | n-Heptyl | n-Octyl | Ethyl Melt Point o o -- -- o o o o o o o o o o Mw (g / mol) 1146.92 978.62 o o o CO 826.24 509.68 551.77 593.85 575.69 617.78 599.89 641.97 t / 0'789 473.65 515.60 CAS N° | Unknown | Unknown | Unknown | | Unknown | 405264-17-7 | Unknown | | Unknown | 405264-15-5 405264-16-6 | Unknown | 61183-76-4 | Unknown | Unknown | Unknown | Raw Formula C72H143N3O6 C60H119N3O6 C51H89N3O6 C50H87N3O6 C27H47N3O6 C30H53N3O6 C33H59N3O6 C33H41N3O6 C36H47N3O6 C33H65N3O6 C36H71N3O6 C39H77N3O6 C24H47N3O6 C24H41N3O9 CE Simplified Name Ethyl-N(n-Dec)2         | Ethyl-N(2-EtHex)2 (l-Me)3-Et-N(CyHex)2 (l-Me)2-Et-N(CyHex)2 Ethyl-N Piperidine         | Ethyl-N(Azepane)        | Ethyl-N(Azocan)         | Ethyl-N(Phenyl, Me)        | Ethyl-N(Ph,Me) Ethyl-N(n-Hex, Me)        | Ethyl-N(n-Hept, Me) (ETH 227 - Sodium Ionophore 1) Ethyl-N(n-Oct, Me)        | Ethyl-N(Et)2 Ethyl-N(Morpholine)       | Code N° | CE26 CE27 | CE28 | CE29 | CE30 | CE31 | CE32 | CE33 | CE34 | CE35 CE36 | CE37 00 rn | CE39 Experimental design No. 9: Synthesis of extractants and density of formulations As the various extractants CE00 to CE39 were synthesized, the impact of the extractant on the density of formulations with 3 equivalents of anionic solvating agents and molar concentrations of CE of 0.2 and 0.3 mol / L respectively was examined on 3 to 5 mL of formulation. The results obtained are illustrated for a number of them in Figure 14. A relatively logical trend was obtained. The higher the molar mass of the extractant, the more it has a negative impact on the density of the formulation. Lowering the molar mass of the extractant is therefore of interest, with the limit being its solubility in water. Experimental design No. 10: Viscosity of a low-molecular-weight extractant formulation As the viscosity measurement required 15 to 20 mL of formulation, it was decided to synthesize an extractant with a low molar mass and relatively easy synthesis to obtain more than 50 grams of Et-NPiperidine (CAS n° 405264-17-7) (1H NMR: 4.02 (s, 6H), 3.53 - 3.40 (m, 6H), 3.34 (s, 12H), 1.54 (dd, J = 20.0, 14.4 Hz, 18H), 1.38 (d, J = 7.6 Hz, 2H), 0.81 (t, J = 7.6 Hz, 3H)) for the production of formulations incorporating from 1.5 to 5 grams of this extractant. In addition to its low molar mass, this product turned out to be an oil, which suggests that the formulations tested are representative of the minimum viscosities that can be obtained with this family of tripod extractants. The results obtained are summarized in Figure 15. It appears that the viscosity is reduced by an average of 53%, enabling CE concentrations of 400 mmol / L to be approached with a limit of 20 centipoise at 20°C, representing a gain in extraction capacity of around 33% compared to formulations with the Li VIII ionophore / CE00. Experimental design No. 11: Extraction performance of compounds of interest The aim here is to implement exactly the design of experiment n°1 already presented, but for new cationic extractants CE01 to CE39. Some of the extraction results obtained are given in Table 28. Code N° CE Simplified Name [CEJ^g (mmol / L) Density F (kg / L a 20°C) [Li+]forg (mmol / L) [Na+]forg (mmol / L) [K+]forg (mmol / L) [Ca2+]forg (mmol / L) %Use Li (%) %Use Na (%) %Use K (%) Keq (Li) Keq (Na) Keq (Ca) CEOO Ethyl-N(CyHex)2 45.5 1.282 37.75 28.45 0.00 34.55 83.0% 62.6% 76.0% 49.8 1.24 0.91 CEO1 Methyl-N(CyHex)2 45.3 1.283 36.25 29.35 0.00 33.80 80.0% 64.8% 74.6% 40.3 1.37 0.84 CE02 i-Prop-N(CyHex)2 42.1 1.283 38.75 31.40 0.00 38.70 92.0% 74.6% 91.9% 140 2.44 4.14 CE03 n-Butyl-OC-N(CyHex)2 43.6 1.282 39,00 28.90 0.00 33.50 89.4% 66.3% 76.8% 95.9 1.54 1.04 CE04 l-Me-Et-N(CyHex)2 45.5 1.282 39.10 33.05 0.00 40.30 85.9% 72.6% 88.6% 63.4 2.01 2.38 CE05 CyHex-N(CyHex)2 40.5 1.284 31.00 27.80 0.00 35.30 76.5% 68.6% 87.2% 38.1 1.88 2.59 CE06 PhCOC-N(CyHex)2 42.5 1.284 38.65 29.15 0.65 33.90 90.9% 68.6% 79.8% 119 1.77 1.31 CE07 H-N(CyHex)2 44.6 1.283 31.05 21.05 0.00 26.20 69.6% 47.2% 58.7% 21.6 0.65 0.38 CE08 Ethyl-N(CyOct)2 44.9 1.279 39.55 30.70 0.00 40.05 88.0% 68.3% 89.2% 78.9 1.64 2.60 CE09 Et hyl - N (CyOct,t- But) 45.4 1.279 32.00 26.30 0.00 32.40 70.5% 57.9% 71.4% 22.5 1.01 0.70 CE1O Ethyl-N(CyHex,Et) 42.7 1.284 27.95 29.90 0.05 26.20 65.4% 70.0% 61.3% 19,0 1.88 0.47 CE11 Ethyl-N(CyHex, iProp) 38.1 1.285 29.85 25.75 0.00 30.30 78.4% 67.6% 79.6% 48.1 1.95 1.64 CE21 Ethyl-N(s-But)2 41.1 1.281 31.20 30.20 0.10 33.00 75.9% 73.4% 80.2% 35.7 2.35 1.45 CE22 Ethyl-N(n-But)2 43.7 1.280 28.75 33.60 0.20 22.25 65.8% 76.9% 50.9% 18.7 2.66 0.28 CE23 Ethyl-N(i-But)2 43.2 1.280 26.00 28.80 0.70 26.40 60.2% 66.7% 61.2% 14.5 1.59 0.46 CE24 Ethyl-N(n-Hex)2 41.7 1.277 32.75 39.05 0.20 27.70 78.6% 93.7% 59.3% 40.7 5.88 0.44 CE25 Ethyl-N(n-Oct)2 46.0 1.271 23.30 27.35 0.60 19.55 50.7% 59.5% 42.5% 8.39 1.07 0.17 CE26 Ethyl-N(n-Dec)2 45.8 1.267 22.50 26.30 0.20 19.05 49.1% 57.4% 41.6% 7.86 0.98 0.17 CE27 Ethyl-N(2-EtHex)2 45.0 1.271 23.90 28.60 6.00* ? 22.90 53.1% 63.6% 50.9% 9.72 1.31 0.26 CE3O Ethyl-N Pi peridine 45.7 1.286 23.60 25.95 0.25 21.30 51.6% 56.8% 46.6% 9.0 0.97 0.22 CE34 Ethyl-N(Ph,Me) 43.5 1.287 26.45 34.45 0.45 19.85 60.8% 79.1% 45.6% 14.7 3.06 0.22 CE35 Ethyl-N(n-Hex, Me) 44.2 1.281 25.00 29.75 0.05 22.95 56.6% 67.3% 51.9% 11.7 1.59 0.29 CE37 Ethyl-N(n-Oct, Me) 43.1 1.279 23.15 27.90 0.14 22.30 53.7% 64.7% 51.7% 10.7 1.45 0.30 CE38 Ethyl-N(Et)2 43.3 1.284 25.05 29.75 1.65 24.35 57.9% 68.7% 56.2% 12.9 1.74 0.36 CE39 Ethyl-NMorpholine 44.5 1.288 8.20 13.50 0.15 0.10 18.4% 30.3% 0.22% 1.61 0.31 0.005 [Table 28] These results show that: 1. For all the compounds, with the exception of Et-N(Morpholine), CE39, a high level of use of the extractant with respect to lithium was maintained, with variability in Keq (Li) but Keq (Na) and Keq (Ca) always low, 2. A liquid extractant is very accessible by functionalizing the amide (R1, R2), 3. The use of cyclic and / or branched chains in R1 and R2 favours Li / Na selectivity and therefore the extraction of Li+ / Na+. 4. The use of linear alkyl chains with more than 4 carbons favours Li / Ca selectivity and therefore the extraction of Li+ / Ca2+. 5. The use of a long or branched alkyl chain or an electrondonating group in R3 increases the usage rate of usage of the extractant. 6. Replacing an R4, R5 and / or R6 hydrogen with at least one short-chain alkyl improves lithium extraction capacity while lowering the melting temperature of the extractant. Following these promising results, work continued on the study of extraction phases at 20°C and de-extraction at 80°C using multi-salt brines for formulations incorporating the targeted extractants, some of which are presented below. Experimental design No. 12: Implementation of a formulation incorporating CE21 to demonstrate the possible use of these various tripodants in the selective extraction of LiCl. For a liquid organic formulation composed of [CE]lorg = 80 mmol / L of ionophore CE21 and 4 equivalents of anionic solvating agent (AS), i.e. 320 mmol / L of N-(3,4-dichlorophenyl)-octanamide (C14H19Cl2NO,     (CAS 730-25-6), all dissolved in 2- chlorobromobenzene (2CBB) C6H4BrCl, CAS 694-80-4), extraction was carried out at 23°C on a multi-salt brine, then the deextraction of the previously absorbed salts was assessed by contacting it with demineralized water at 80°C for A / Ode-ext of 0.2 and 1. These tests were used to assess the influence of this ratio on the de-extraction yields of the various ions. The brine used for extraction, which is representative of real lithium-rich brine, was created in the laboratory from demineralized water and pure salts (> 99.9%). After analysis, its salinity is 286.5 g / L and its ionic composition is shown in Table 29. [Table 29] Test / lons Li+ Na+ K+ Ca2+ Mg2+ Cl 10 0.156 mol / L 3.878 mol / L 0.247 mol / L 0.033mol / L 0.327 mol / L 5.00 mol / L (1082 mg / L) (89.17 g / L) (9.675 g / L) (1.33 g / L) (7.95 g / L) (177.3 g / L) The extraction and de-extraction protocol previously presented is maintained for each of these tests with the exception of the A / Ode-ext given above. Firstly, a single contact extraction is carried out at a ratio (O / A)ext = 1 with 10 mL of organic phase and 10 mL of brine. Liquid-liquid extraction performance is shown in Table 30. [Table 30] (O / A)ext= 1 Li+ Na+ K+ Ca2+ Mg2+ cr Brine to de treated (mmol / L) 155.9 3 879 247.4 33.1 327 5 002 Treated brine (mmol / L) 135.4 3 880 247.4 28.4 321.6 4 964 E|Vln+(%) 13.2% 0.0% 0.0% 14.3% 1.7% 0.8% SF(Li+ / Mn+) / 22.4 197 0.94 2585 / The results of de-extraction with demineralized water at 80°C are summarized in Tables 31 and 32. [Table 31] (A / O) de-extract ion [Li+]forg (mol / L) [Na+]forg (mol / L) [K+]forg (mol / L) [Ca2+]forg (mol / L) [Mg2+]forg (mol / L) [cr]forg (mol / L) 0 21.04 26.92 0.20 4.689 0.019 57.6 0.2 1.25 3.82 0.10 0.65 0.02 4.82 1 0.36 2.14 0.13 0.148 0.008 4.62 [Table 32] (A / O) de-extraction E’u(%) E'k(%) E'ca(%) E’Mg(%) E'o(%) 0.2 94% 86% 46% 86% 12% 92% 1 98% 92% 35% 97% 60% 92% By comparison, by replacing CE21 with CE00, the Li VIII ionophore, the extraction performance obtained is shown in Table 33. [Table 33] (O / A)„t=l Li+ Na+ K+ Ca2+ Mg2+ Cl Brine to de treated (mmol / L) 155.9 3 879 247.4 33.1 327 5 002 Treated brine (mmol / L) 104.3 3 867 246.2 32 319.6 4 920 Emh+(%) 33.1% 0.3% 0.5% 3.5% 2.3% 1.6% SF(Li+ / Mn+) / 136 717 47 9 119 / Lithium extraction performance was improved, from 13.2% to 33.1%, but above all calcium extraction was reduced, from 14.3% to 3.5%. It should also be noted that the separation factors (SF) were significantly improved for all cations. The same work on other tripods gave, for example, for CE11, a liquid extractant, a lithium extraction yield of 30.1% and a calcium extraction yield of 4.5%, while others were even better. Example: For a liquid organic formulation composed of [CE]^rg = 0.34 mol / L of ionophore CE11 and 3 equivalents of anionic solvating agent (AS), i.e. 1.02 mol / L of N-(3,4-dichlorophenyl)-octanamide (C14H19Cl2NO, CAS 730-25-6), all dissolved in 2-chlorobromobenzene (2CBB)(C6H4BrCl, CAS 694-80-4), the aim is to implement a liquid-liquid extraction process for LiCl by temperature modulation between a multi-salt brine to be treated at 20°C and demineralized water at 80°C using 4 stages of mixers-decanters for extraction at 20°C and a stirred column with 3 theoretical stages for de-extraction at 80°C. The LiCl extraction phase is carried out with a (O / A)ext of 1.1 at 20°C and the LiCl de-extraction phase is carried out with a (O / A) de-ext of 10 at 80°C. The brine used for extraction is a reconstituted from a published reference composition from the Maricunga salt flat in Chile. It was created in the laboratory from demineralized water and pure salts (> 99.9%). After analysis, its salinity is 306.4 g / L and its composition is shown in Table 34. [Table 34] Test / lons Li+ Na+ K+ Ca2+ Mg2+ Cl 11 0.163 mol / L (1132 mg / L) 3.718 mol / L (85.48 g / L) 0.211 mol / L (8.260 g / L) 0.338 mol / L (7.95 g / L) 0.302mol / L (7.345 g / L) 5.36 mol / L (189.9 g / L) The associated McCabe-Thiele diagram is shown in Figure 16. The process diagram used to illustrate this implementation is shown in Figure 17. The four extraction stages are carried out by the four serial mixers [1a] to [4a] associated with the four serial decanters [1dc] to [4d], of which [1dc] is a centrifugal decanter. The heat exchangers [1e] and [2e] are used to heat and cool the organic phase and the de-extraction water respectively. Finally, the hot countercurrent de-extraction column is shown in [1c]. The material balance obtained for a production equivalent to 12,285 tons of LiCl per year is given in Table 35 for 21.5 tons of water / h fed in [A1]. The lithium extraction and production yield here is 93%. [Table 35] Ions Feed [SI] Raffinate [S5] De-extract [P2] SF(Li+ / Mn+) Composition in g / L Li+ 1.132 0.08 10.229 / Na+ 85.479 84.77 11.175 972 K+ 8.26 8.302 0.0124 85 665 Mg2+ 7.345 7.382 0.011 85 677 Ca2+ 13.531 12.473 10.916 146 SO42- 0.722 0.726 0.007 137 450 Cl- 189.923 181.73 88.836 / h2o 894.84 899.514 959.445 TDS-Total Salinity 306.393 295.463 121.18 Ions Feed [SI] Raffinate [S5] De-extract [P2] SF(Li+ / Mn+) Composition in mol / L Li+ 0.163 0.012 1.474 / Na+ 3.718 3.687 0.486 972 K+ 0.211 0.212 0.0003 85 665 Mg2+ 0.302 0.304 0.0004 85 677 Ca2+ 0.338 0.311 0.272 146 SO42‘ 0.008 0.008 0.0002 137 450 Cl- 5.357 5.126 2.506 / H2O 49.671 49.931 53.257 Density (kg / L) 1.201 1.195 1.081 Flow rates (m3 / h) 218.2 217.1 22.4 Main flow rates in tons / h LiCI 1.51 0.11 1.4 NaCI 47.4 46.8 0.64 CaCI2 8.18 7.5 0.68 H2O 195 195 21.5 This basic material balance can be significantly improved in terms of the purity of the desorbed LiCl by using intermediate 10 washing steps for the organic phase after the extraction phase of the LiCl from the brine. A single stage of washing the organic phase after extraction with (A / O)wash = 0.05 makes it possible to reduce the sodium concentration Na+ of the de-extract from 0.486 mol / L to 0.076 mol / L (SF = 3330) and the calcium concentration Ca2+ from 0.272 mol / L to 0.026 mol / L (SF = 865) without any major deterioration in the lithium production yield, which falls from 93% to 90.5% for an (A / O)ext of 1.1. Experimental design No. 13: Introduction of other extractants from this family and associated Li / Na selectivity experimental results. Compounds CE40 to CE43 were synthesised and incorporated into various formulations and experiments. The extractants CE40 to CE43 are all in solid form and are unknown in the literature [Table 37]. The aim here is to carry out selective Li+ / Na+ extraction tests, in duplicate, from an aqueous solution comprising 0.1 mol / L LiCl, 0.1 mol / L NaCl, in the presence of an excess of 1.5 mol / L MgCl2, for ionophores CE00, CE02, CE27, CE40 and CE43 via a liquid organic formulation composed of 0.1 mol / L of Cationic extractant CE for 8 equivalents of anionic solvating molecule (ASM), i.e. 0.8 mol / L of N-(3,4-bis(dichlorophenyl)octanamide (C14H19Cl2NO, CAS N°: 730-25-6), all dissolved in 1-bromo-2-chlorobenzene (2CBB) (C6H4BrCl, CAS N°: 694-80-4). [Table 37] Code N° CE Simplified Name Raw Formula CAS N° Mw (g / mol) Melt Point RI R2 R3 R4 R5 R6 CE40 Eti lo-N (i-Propyl )2 C30H59N3O6 Unknown 557.82 90-92°C i-Propyl i-Propyl Ethyl H H H CE41 i-Propyl-N(i-Propyl)2 C31H61N3O6 Unknown 571.84 Solid i-Propyl i-Propyl i-Propyl H H H CE42 t-Butyl-N(i-Propyl)2 C32H63N3O6 Unknown 585.87 Solid i-Propyl i-Propyl t-Butyl H H H CE43 t-Butyl-N(CyHex)2 C50H87N3O6 Unknown 826.26 Solid Cyclohexyl Cyclohexyl t-Butyl H H H The saline aqueous phases to be tested for extraction were created in the laboratory from demineralized water and pure salts (> 99.9%). The extraction and de-extraction protocol presented above was followed for each of these tests. The experimental results are presented in Tables 38 and 39 below. [Table 38] N° (mmol / L) Li+ Na+ ,, 2+ Mg Cl’ Li+ Na+ ,, 2+ Mg Dm Dm Initial Water 95.6 97.2 1 459 3111 Organic Li+ Na+ CE27 Raffinate 73.7 90.2 1 459 3 082 21.9 7.00 0.00 0.3 0.08 CE40 53.8 90.1 1 459 3 062 41.8 7.14 0.00 0.78 0.08 CEOO 35.9 92.3 1 459 3 047 59.7 4.96 0.00 1.66 0.05 CE02 31.2 93,0 1 459 3 043 64.4 4.27 0.00 2.06 0.05 CE43 19.9 91.6 1 459 3 030 75.7 5.65 0.00 3.81 0.06 [Table 39] N° SF % Ext % Ext % Ext % Use % Use %mol Li / Na Li+ Na+ ., 2 + Mg Li+ Na+ CE27 3.8 22.9% 7.2% 0.0% 21.9% 7.0% CE40 9.8 43.7% 7.3% 0.0% 41.8% 7.1% CEOO 31,0 62.5% 5.1% 0.0% 59.7% 5.0% CE02 44.9 67.3% 4.4% 0.0% 64.4% 4.3% CE43 61.7 79.2% 5.8% 0.0% 75.7% 5.7% It appears here that the "head" of the extractant, R3, plays a significant role in the selectivity of the cationic extractant for lithium compared with sodium and that the amine chosen via R1 & R2 has little impact on the sodium extraction rate, which remains low in the presence of lithium. The CE extractant can therefore be judiciously chosen, depending on the ionic composition of the lithium-rich brine to be treated, to enable maximum technical and economic performance. Experimental design No. 14: Feasibility of using a variety of anionic solvating molecules for the selective extraction of LiCl using the extractant CE02. The aim here is to carry out LiCl extraction tests, from an aqueous solution comprising 0.05 mol / L LiCl, in the presence of an excess of 1.5 mol / L MgCl2, for twelve anionic solvating molecules (ASM) present in a liquid organic formulation composed of 0.1 mol / L of the cationic extractant CE02 for 5 equivalents of anionic solvating molecule (ASM), i.e. 0.5 mol / L, all dissolved in 1,2-dichlorobenzene (DCB) (C6H4Cl2, CAS: 90-50-1). The saline aqueous phases to be tested for extraction were created in the laboratory from demineralized water and pure salts (> 99.9%). The extraction and de-extraction protocol presented above was followed for each of these tests. The experimental extraction rates for LiCl are presented for each of the ASMs in Table 40 below. [Table 40] Conc. CE02 : 0,1 M Conc. ASM : 0,5 M Solvent : DCB XH / X-pKa LiCl Extraction rate CAS n°: 349-75-7 3-(Trifuoromethyl)-benzenemethanol F F. / /                 ''OH F 14.17 21.6% CAS n°: 550309-38-1 N-(3-Bromophenyl)-octanamide H 0 14.5 54.8% CAS n°: 348594-52-5 N-(3-Chlorophenyl)-Octanamide H ° 14.45 55.1% CAS n°: 549476-22-4 N-(3-Fluorophenyl)-octanamide H F. XT X 14.39 56.6% CAS n°: 3859-94-7 N - [ 3-(Trifluoromethyl)-phenyl] octanamide F F\ /       H / \      / N\ / F u » 14.2 62.1% CAS n°: 1207319-21-8 3,4-dichloro-N-(3,4-dichlorophenyl)-Benzanamine Cl                                           Cl Ci ----4         >----N--------Cl 14.0 60.7% CAS n°: 20398-46-3 13.83 69.8% N-(3,5-Dichlorophenyl)-octanamide H Cl      / :¾..                                  / XT I Cl CAS n°: 730-25-6 N-(3,4-Dichlorophenyl)-octanamide H Cl          .N.                      / XX X 13.63 71.4% CAS n°: 904565-54-4 N-[3,5-Bis(trifluoromethyl)-phenyl]-2,2,3,3,4,4,4-heptafluorobutanamide F                      f f F      /                                 F         F / X     n \ XX XX ■'{J IK’ X ,X 0 p F^ 9.1 (calc) 72.9% CAS n°: 1974318-14-3 N-[3,5-bis(trifluoromethyl)-phenyl]-Octanamide ' XT » 13.6 73.5% CAS n°: unknown N-(3,4,5-Trifluorophenyl)-octanamide H F \ / N / XT T F 12.53 74.7% CAS n°: 32707-86-1 N-[3,5-bis(trifluoromethyl)-phenyl]-3,5-bis(trifluoromethyl)-Benzenamine F                H                F F\ / 1 \^F F XX XX f 11.45 (calc) 86.0% It has been shown here that the use of a lithium extractant molecule, CE02, combined with one or other of the anionic solvating molecules (Cl- being the anion in this case), from among those previously described, once dissolved in a polar aromatic solvent, 1-bromo-2-chlorobenzene (2CBB) in this case, ensures good extraction of LiCl from an aqueous phase to an organic phase by the liquid-liquid route according to the invention. References [1] Gabra & Torma - Hydrometallurgy, 1978, 3, pp. 23-33 [2] Bukowsky & Uhlemann - Separation science and Technology, 1993, 28(6), pp. 1357-1360 [3] Hano & al - Solvent Extraction and Ion Exchange, 1992, 10(2), pp. 195-206 [4] D. Gao & al - Journal of Chemical Engineering of Japan, 2016, Vol. 49, No. 2, pp. 104-110 [5] Zhou & al - J. Chem. Eng. Data 2011, 56, pp. 3518-3522 [6] Zhou & al - Ind. Eng.Chem. Res, 2012, 51, pp. 12926-12932 [7] Hui-fang & al - Hydrometallurgy, 2016, 160, pp. 1-5 [8] Zhou & al - ACS Sustainable Chem. Eng, 2019, 7, 9, pp. 88858892 [9] Kamenica & al - Sensors, 2017, 17, pp 2430

Claims

1. - Hydrophobic organic liquid composition for theselective extraction of a di-ionic lithium salt comprising a lithium cation and an anion complementary to the lithium cation chosen in particular from Cl-, I-, Br-, CN-, NO3-, HCO3- from a lithium-rich brine to be treated, the said composition comprising:(A) at least one compound extracting the lithium cation, chosen from compounds of formula:in which:- R1 and R2, which may be identical or different, are, irrespective of their position on a nitrogen atom, independently selected from linear or branched C1-C12 alkyl, aryl, C4-C8 cycloalkyl; or- R1 and R2, taken together with the nitrogen atom carrying them, form a five-, six-, seven- or eight-membered ring;- R3 is selected from hydrogen, linear or branched C1-C8 alkyl,    C4-C8    cycloalkyl,    C2-C6   alkoxyalkyl    andalkoxyalkylaryl;-   R4 is selected from hydrogen,  linear or branched C1-C3alkyl;-   R5 is selected from hydrogen,  linear or branched C1-C3alkyl;2024229114   26 Aug 2026- R6 is selected from hydrogen, linear or branched C1-C3 alkyl;(B) at least one hydrophobic protic organic compound which solvates the anion complementary to the lithium cation; and (C) at least one hydrophobic polar organic diluent having a flash point at atmospheric pressure greater than 60°C, preferably greater than 75°C, more preferably greater than 90°C.

2. - Hydrophobic organic liquid composition according to Claim 1, characterized in that the compound extracting thelithium cation has a molar mass of at least 450 g / mol, preferably of at least 550 g / mol.

3. - Hydrophobic organic liquid composition accordingto one of claims 1 and 2, characterized in that the compound extracting the lithium cation has a complexation constant Log K for this cation in methanol at 25°C of at least 1, preferably greater than 2.

4. - Hydrophobic organic liquid composition accordingto one of Claims 1 to 3, characterized in that the compound extracting the lithium cation exhibits a negative variation in enthalpy during the complexation of the lithium cation, AH , associated with an absolute value of the ratio of the variation in enthalpy on complexation of the lithium cation AH to the variation in entropy on complexation of the lithium cation, AS, at the temperature T=298K, |AH / (TAS)| greater than 2, preferably greater than 5.

5. - Hydrophobic organic liquid composition accordingto one of claims 1 to 4, characterized in that the compound extracting the lithium cation has a melting temperature below 200°C, preferably below 50°C and more preferably below 25°C.2024229114   26 Aug 2026

6. - Hydrophobic organic liquid composition accordingto one of claims 1 to 5, characterized in that:- R1 and R2 are, whatever their position on a nitrogen atom, independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, 2-methylbutyl, 2-ethylpropyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, 2-ethylhexyl, phenyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl; or- R1 and R2, taken together with the nitrogen atom carrying them, form a pyrrolidine, piperidine, azepane or azocane ring;- R3 is selected from hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, 2-methylbutyl, 2-ethylpropyl, n-hexyl,    cyclohexyl,    methoxymethyl,    methoxyethyl,methoxypropyl, methoxybutyl and -CH2-O-CH2-Phenyl; and-   R4, R5 and R6 are hydrogen or methyl,R1 and R2 being advantageously chosen from butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl or phenyl if the brine to be treated has a calcium concentration of more than 10 g / L and / or the selectivity Li+ / Ca2+ is priviledged; andR1 and R2 being advantageously chosen from iso-propyl, isobutyl, sec-butyl, tert-butyl, iso-pentyl, 2-methylbutyl, 2-ethylpropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl or R1 and R2, taken together with the nitrogen atom carrying them, form a pyrrolidine, piperidine, azepane or azocane ring when the brine to be treated has a calcium concentration of less than 10 g / L and / or when Li+ / Na+ selectivity is priviledged.

7. - Hydrophobic organic liquid composition accordingto one of claims 1 to 6, characterized in that the compound extracting the lithium cation is chosen from:2024229114   26 Aug 2026X o N     OO '-- /         O     Xn ’ oC - GA 1 w \ 0 A A x ox XX XX ox 9 09 XX XX / ° x 0 Ox ■ 9- <V xx A " ~1X CE00 CE01 CE02 9 A Cl XX z ■ • ■H3 0 A p r-\ A 1 XV ( / — N            ) 0 ) < 1-- '1    ■ / OX / —\ N-\   / CE03 CE04 CE05 p O o o^X^  Q o          n O-Ll'l N H              / ---\ \ / 0^^0^\_ / r\ /     0\      N ( )— N           ) 0 ) x ■: (     }— N    0— / > 0—\ x A i X 0 o! X N-- 9 CE06 CE07 CE08 OA v^-    0 0=^ A n-~A 0 N^ \ ■H3 vCC> X Q n     00 A 1 xv 0           y     0    x—CH3 Ox AA N CH3 VA°v A ex ^9 CE09 CE10 CE11 Y v . xAA. 1 CJ • / / Yv o j9j Ox AX-A" i A • A. 1 Ad X CE12 CE13 CE142024229114   26 Aug 2026>—• / C / a o 0 / "x / 1 nr 11                     JL xb / ° / 4-t \___ 0 -z\ ^x / 1            II                              ^X / X—n 0         x^j^X CE15 CE16 CE17 1            \ • r-A x-s. /     1 / ) II            o       / X / \ I      II             /                ^h ’ J- A o Q , bbx.n vy A hb 9 "o> d CE18 CE19 CE20 CH3       CH3 c c H3C—\     / ch  Va     h3C\    / CH3 }--N     O-- / 2 O--\    2--- H3C       Ox   >v O           / O     /  CH3 O\    / CH3    \ H3C     N--(        CH3 {   <_ CH3 CH3 OfH EH0\         (" eH3x      xZ 3 / x ' \ / —0 ( '—0 M— / 0£H J4 z 6 ,r A eHO CHi          CH. "‘L— /   y / «       CMi b me             / —V—<            ch, \__ f / \           / me       r»' a.            Cm,          If H       Cm $_ / Q H r CE21 CE22 CE23 CHo A O   0^ ) O^   C6H13 O\         N Hnc6-N          2     o     C6H13 C6H13  0   \ 7N-C6H13 H13C6 CH3 o   ,0^4^O       / C8H17 / --0     #—N h17C8-N^             \       O      C8H17 C8H17 0—Z / N-C8H17 H17C8 CH3 0   / b 0      / 10H21 / --    0     n—N H2lCl0-\             )      0      C10H21 C10H21 0=^ 7N-C10H21 H21C10 CE24 CE25 CE26 V                / X.            -< / oP J"'' J L ' ' yc 4o 0 VV     .   W 0     0 / / -0     a n               '■-------- d- CE27 CE28 CE292024229114   26 Aug 2026CH3 / ""“"X                   .CM. /       1                   r .GHi □ N      0      -;   O ■ { >o 0                    ^J~* 0 [ 0=\ (b CE30 CE31 CE32 CH3 / 3 CH3 ( 3 / r^\ CCH3 Jv C b— N   0— /   0—\ CH3 \= / \— /  0   bN 0 o4 0 b N—CH3 d .9,. 0 MjC”^                 L 00 H3C-N C6H13 -d0-v 0\ d / 0 0=( N C6H13 H3C / C6H13 N \ CH3 CE33 CE34 CE35 CH3 CH3 « .. jj 0                     '0           C8H17 / -- 0       / / —N\ H3C — n            /     0      CH3 C8H17 0=\ N-C8H17 H3C 0 r N\ H3C     / H3C 0^p0^_ 0X / N~\ CH3 CH3 y--CH3 — N \— CH3 CE36 CE37 CE38 \         0     ■ '       1'    0          ✓ b dd /   --•*’     '•-•■    ’ m’ 0 \ / ^4 0 \ u / tY 6 / fl \ / 34° \ H- / V- >-^ CE40 CE41 CE42 ? 0 n 5 * * -cy- Ox CE43

8. - Hydrophobic organic liquid composition accordingto one of claims 1 to 7, characterized in that the hydrophobic2024229114   26 Aug 2026protic organic compound which solvates the anion complementary to the lithium cation has a pKa in water at 25°C of at least 9, preferably at least 10.5, and preferably less than the pKa of water at 25°C, or at least less than 15 at 25°C, and whose solubility in water at 25°C is less than 0.01 mol / l.

9. - Hydrophobic organic liquid composition according to claim 8, characterized in that the hydrophobic protic organic compound which solvates the anion complementary to the lithium cation is a compound of formula (B):(B)in which:- at least one of the radicals RB, RC and RD, which may be identical or different, is a halogen atom or an electronwithdrawing group selected from the following group: F, Cl, Br; CmF2m+i  with m ^ 4, where m is a non-zero integer;CF2CF2CPH2P+1 with p ^ 4, where p is an integer; CF2CpH2p+iwith p ^ 4, where p is an integer; CH2CpF2p+i with p ^ 4,where p is an integer; OCH2CF3; C(=O)CF3; CmHnFpClqBrs withm ^ 4, where n, p, q, s are integers of which at least p, q or s is non-zero; C(=O)OCmH2m+1  with m ^ 4, where m isan integer; and C(=O)CmH2m+1 with m ^ 4, where m is aninteger;- the remaining radical(s) RA, RB, RC, RD and RE are chosen,identically or differently, from the following nonelectroattracting radicals:  H; CH3; CH2CH3; CH2CH2CpF2p+1with p < 4, where p is an integer; CmH2m-1  with m < 10,where m is an integer greater than 1; and CmH2m+1 with m ^10, where m is a non-zero integer; where only one of the2024229114   26 Aug 2026radicals RA to RE may be one of the latter two radicalsCmH2m-1 and CmH2m+1; andX is chosen from the following radicals:OH / C—R'R" • ;.OH;where RA, RB, RC, RD and REwhich may be identical or different,are as defined above in formula (B),where R' and R'', which may be identical or different, are selected from the following radicals: H; CnH2n-i with n h 4, where n is an integer greater than 1; CnH2n+i with n h 4, where n is a non-zero integer; CH2CH2CpF2p+1 with p < 4, where p is aninteger; CH2CpF2p+1 with p h 4, where p is an integer; CF2CpH2p+1 with p h 4, where p is an integer; CF2CF2CpH2p+1 with p h 4, where p is an integer; CmF2m+1 with m h 4, where m is a non-zero integer; CmHnFpClqBrs with m h 4, where n, p, q, s are integers where at least p, q or s is non-zero;and where R''' is selected from the following radicals: CmH2m+1with m h 20, where m is an integer; CmH2m-1 with m h 20, where mis an integer greater than 1; CmHnFpClqBrs with m h 10, where n,p, q, s are integers in which at least p, q or s is non-zero; CH2CH2CpF2p+1 with p h 4, where p is an integer; CH2CpF2p+1 with ph 4, where p is an integer; CF2CpH2p+1 with p h 4, where p is aninteger; CF2CF2CpH2p+1 with p h 4, where p is an integer; CmF2m+1with m h 4, where m is a non-zero integer; and an aryl radicalof formula (b):(b)2024229114   26 Aug 2026where RA, RB, RC, RD and RE, which may be identical or different,are as defined above in formula (B).

10. - Hydrophobic organic liquid composition accordingto claim 9,characterized in that in the compound of formula (B)X represents

11. - Hydrophobic organic liquid composition accordingto claim 10, characterized in that compound (B) is representedby the formula:(C):or(D)in which R''is chosen from the following radicals: CmH2m+1 withm ^ 20, preferably ^ 15 where m is an integer; CmH2m-i with m ^ 20, where m is an integer greater than 1; CmHnFpClqBrs with m ^ 10, where n, p, q, s are integers in which at least p, q or sis non-zero;and an aryl radical of formula(b):where RA, RB, RC, RD and REwhich may be identical or different,are as defined in formula (B) in claim 8.

12. - Hydrophobic organic liquid composition accordingto claim 11, characterized in that the radical R''' is n-C7H15, n-C9H19, n-C11H23 or n-C13H27.2024229114   26 Aug 2026

13. - Hydrophobic organic liquid composition according to one of claims 1 to 12, characterized in that the at least one compound extracting the lithium cation is present in the composition at a concentration of 0.15 to 1 mol / L, preferably of 0.3 to 1 mol / L, more preferably of 0.45 to 1 mol / L.

14. - Hydrophobic organic liquid composition according to claim 13, characterized in that the ratio of the molar concentration of the at least one hydrophobic protic organic compound which solvates the anion complementary to the lithium cation to the molar concentration of the at least one compound which extracts the lithium cation is from 1 to 10, preferably from 1.5 to 5 and more preferably from 2 to 4.

15. - Hydrophobic organic liquid composition according to one of claims 1 to 14, characterized in that the hydrophobic polar organic diluent has a viscosity at 20°C of less than 5 mPa.s, preferably of less than 2 mPa.s.

16. - Hydrophobic organic liquid composition according to one of claims 1 to 15, characterized in that it has a density at 20°C greater than 1.20 kg / L, preferably greater than 1.25 kg / L, more preferably greater than 1.30 kg / L, for a viscosity at 20°C of less than 50 mPa.s, preferably less than 25 mPa.s, for a brine to be treated with a density at 20°C at least 0.05 kg / L lower.

17. - Hydrophobic organic liquid composition according to one of claims 1 to 15, characterized in that it has a density at 20°C greater than 1.25 kg / L, preferably greater than 1.30 kg / L, more preferably greater than 1.35 kg / L, for a viscosity at 20°C of less than 30 mPa.s, preferably less than 15 mPa.s, for a brine to be treated with a density at 20°C at least 0.15 kg / L lower.2024229114   26 Aug 2026

18. - Use of the hydrophobic organic liquid composition according to one of claims 1 to 17 in a process for extracting lithium salt, the said process comprising a step of mixing, at a first temperature, the hydrophobic organic liquid composition and the brine to be treated, a step of separating the hydrophobic organic liquid composition loaded with lithium salt and the treated brine and a step of regenerating the hydrophobic organic liquid composition by treating the hydrophobic organic liquid composition loaded with lithium salt with a treatment water, the said regeneration step being carried out at a second temperature, higher than the first temperature, the difference between the first temperature and the second temperature being from 30 to 150°C, preferably from 50 to 100°C, more preferably from 60 to 80°C.

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