Novel lithium extraction agents, liquid organic mixtures thereof and methods of lithium extraction by solventing

Abstract

The present disclosure provides a compound of formula (I) for use as a lithium extraction agent. Also provided are liquid organic mixtures for lithium extraction comprising the aforementioned compound and methods of extracting lithium.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium extraction, in particular to compounds for extracting lithium from aqueous solutions containing lithium, combinations and methods of use thereof. More specifically, the present application relates to extraction compositions using phenolic compounds as lithium extractants and methods of using the extraction compositions to extract lithium. BACKGROUND

[0002] Lithium is widely used in the fields of batteries, glass, alloys, ceramics, lubricants, etc. With the explosive growth of demand for lithium salts in the power battery industry, lithium has been hailed as the "energy metal of the 21st century". Lithium mainly exists in solid minerals such as spodumene, lepidolite and lithium clay, and in liquid minerals such as salt lake brine, oilfield brine and geothermal water. However, the development of any type of lithium mine inevitably involves a stage of extracting lithium from aqueous solutions containing alkali and alkaline earth metals. Developing compounds and combinations that have a special selectivity for lithium is a key area for efficient lithium extraction.

[0003] Currently, the main methods for extracting lithium salts from aqueous solutions containing lithium at home and abroad include precipitation, adsorption, ion exchange, electrodialysis membrane, nanofiltration membrane, and solvent extraction. Solvent extraction has the advantages of high efficiency, strong selectivity, simple process and equipment, continuous operation, and easy automatic control. Moreover, existing extraction technologies can achieve magnesium-lithium separation, calcium-lithium separation, and sodium (potassium)-lithium separation, and can extract lithium from old brine containing lithium and lithium precipitation mother liquor. Common reagents used for lithium extraction include: tributyl phosphate-iron trichloride composition, beta-diketone-neutral phosphine composition, pyrazolone-TBP composition, crown chemistry, and neutral amide.

[0004] The tributyl phosphate-ferric chloride composition can extract lithium from a lithium-containing solution with a high concentration of chloride ions; the β-diketone-neutral phosphine composition can extract lithium from an alkaline lithium-containing solution. The tributyl phosphate-ferric chloride composition is strong in corrosion of equipment in the extraction process; the crown-shaped chemical species is difficult to synthesize and has high cost, and lacks industrial application prospects. The β-diketone compound used for extracting lithium from an alkaline lithium-containing solution is also relatively high in price, and is significantly lost due to a short alkyl chain; the fluorine-containing β-diketone compound capable of directly extracting lithium from a weakly alkaline lithium-containing aqueous solution is also high in manufacturing cost, which also limits its industrial application to some extent. In addition, salicylate (phenyl salicylate

Chinese invention patent CN202210079673.5

Tsivadze AY, Bezdomnikov AA, Baulin VE, Demina LI, Birin KP, Baulin DV, Rogacheva YI. A New Extraction System Based on Isopropyl Salicylate and Trioctylphosphine Oxide for Separating Alkali Metals. Molecules. 2022 May 10; 27(10): 3051. doi: 10.3390 / molecules27103051. PMID: 35630527; PMCID: PMC9146891.

[0005]

[0006] Therefore, there is a need to develop a new lithium extractant, extraction composition and extraction process to meet the economic and efficiency requirements of industrial applications. SUMMARY

[0007] The present inventors have developed a new lithium extractant to overcome one or more of the above-mentioned deficiencies of existing lithium extractants.

[0008] In one aspect, the present disclosure provides a lithium extractant, which is a compound of formula (I),

[0009]

[0010] wherein R1is hydrogen, C 1-8 alkyl, C 3-6 cycloalkyl or phenyl, said C 1-8 alkyl, C 3-6 cycloalkyl or phenyl optionally substituted with one or more substituents selected from the group consisting of hydroxy, halogen, C 1-6 alkyl, C 1-6 alkoxy or nitro; 1-6 alkyl or C 1-6 alkoxy optionally further substituted with one or more substituents selected from the group consisting of hydroxy, halogen, C 1-6 alkyl, C 1-6 alkoxy or nitro.

[0011] R2, R3, R4and R5are each independently hydrogen, halogen, nitro, benzyloxy, C 1-6 alkyl or C 1-16 alkoxy, said benzyloxy, C 1-6 alkyl or C 1-16 alkoxy optionally substituted with one or more substituents selected from the group consisting of hydroxy, halogen, C 1-6 alkyl, C 1-6 alkoxy or nitro.

[0012] Yet another aspect of the present disclosure provides use of the above-mentioned compound of formula (I) as a lithium extractant in the extraction of lithium.

[0013] Yet another aspect of the present disclosure provides a liquid organic mixture for the extraction of lithium, comprising: one or more of the above-mentioned compound of formula (I), a synergist, and optionally a diluent.

[0014] Yet another aspect of the present disclosure provides a method for the extraction of lithium, comprising:

[0015] contacting the above-mentioned liquid organic mixture for the extraction of lithium with an aqueous solution containing lithium ions, allowing the lithium ions in the aqueous solution to enter the organic layer by liquid-liquid demixing, and collecting the organic layer. DETAILED DESCRIPTION

[0016] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application are described clearly and completely below. The embodiments described below are exemplary and are only used to explain the present application, and should not be understood as a limitation of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort should fall within the scope of protection of the present application.

[0017] The application can be implemented in other specific forms without departing from its essential attributes. It is to be understood that any and all embodiments of the application can be combined with the technical features of any other embodiment or embodiments, to the extent there is no conflict, to arrive at additional embodiments. The application includes such additional embodiments of combination.

[0018] All publications and patents mentioned in the present disclosure are hereby incorporated by reference in their entirety into the present disclosure. To the extent there is a conflict between the uses or terms of any publication or patent incorporated by reference and the uses or terms of the present disclosure, the uses and terms of the present disclosure control.

[0019] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0020] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs. In the event that there is a plurality of definitions for a term herein, those in this section prevail.

[0021] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, percent, period, time, etc. used herein are to be understood as being modified in all instances by the term "about." Also, any numerical range recited herein is intended to include all sub-ranges of the same entire range. Also, any numerical range recited herein is intended to include every integer within the numerical range.

[0022] As used in this disclosure, the terms "comprise", "contain", or "include" and the like are intended to mean that the elements listed after the words are encompassed by the subject matter recited before the words, and are not meant to exclude additional elements. The terms "contain" or "comprise" as used herein can be open, semi-closed, and closed. In other words, the terms also include "consist essentially of" or "consist of".

[0023] The term "optional" as used in this disclosure means that the described situation can or can not occur. For example, a composition comprising an optional diluent means that the composition can or can not include a diluent.

[0024] The term "extractant" as used in this disclosure means a chemical compound that can extract a metal (e.g., lithium, sodium, potassium, etc.) to be extracted into an organic phase by forming a complex through coordination chemistry, and can also back-extract the metal from the organic phase into an aqueous phase through some chemical reaction, thereby achieving purification or enrichment of the metal. The term "extractant" as used in this disclosure can be used interchangeably with the term "extractant". For example, a lithium extractant or a lithium extractant is a chemical compound used to achieve purification or enrichment of lithium through extraction.

[0025] The term "alkyl" refers in the present disclosure to branched and straight-chain monovalent hydrocarbon groups having a number of carbon atoms, n, and a number of hydrogen atoms, 2n+1. Typical alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, hexadecyl, and the like.

[0026] The term "alkoxy" refers in the present disclosure to an alkyl group as defined above attached to the parent structure through an oxygen. Typical alkyl groups include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, isobutoxy, t-butoxy, pentoxy, isopentoxy, neopentoxy, hexoxy, heptoxy, octoxy, 2-ethylhexoxy, nonoxy, decoxy, dodecoxy, hexadecoxy, and the like.

[0027] The term "cycloalkyl" refers in the present disclosure to monocyclic or polycyclic groups containing only carbon and hydrogen, which can be saturated or partially unsaturated. In some embodiments, the cycloalkyl group is a C3-C6 cycloalkyl group. Illustrative examples of cycloalkyl groups include, but are not limited to, the following groups: cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, and the like. In some preferred embodiments, the cycloalkyl group is a cyclopentyl or cyclohexyl group.

[0028] The term "nitro" refers in the present disclosure to the -NO2 group.

[0029] The term "benzyloxy" refers in the present disclosure to the monovalent group PhCH2O- left after the loss of a hydrogen atom on the hydroxyl group of benzyl alcohol.

[0030] The term "halo" or "halogen" refers in the present disclosure to fluorine, chlorine, bromine, or iodine. In some embodiments, "halo" or "halogen" is chlorine or bromine. In other embodiments, "halo" or "halogen" is fluorine.

[0031] Synergist refers in the present disclosure to an agent that, when added to an extractant, is capable of increasing the distribution ratio. Synergist is used interchangeably with synergist in the present disclosure.

[0032] Diluent refers in the present disclosure to an agent that improves the physical properties of the organic phase of the extraction, such as the organic solvent that is the extractant, increases the solubility of the extractant in the organic phase, decreases the viscosity of the extractant increasing its flowability, changes the density of the organic phase.

[0033] The present application aims to disclose a kind of compound with stable properties, cheap, can be selectively extracted from lithium-containing aqueous solution Lithium, and the lithium extraction mixture formed by it. In particular, from low magnesium, calcium lithium salt water, alkaline natural lithium-containing salt water and lithium carbonate / lithium phosphate lithium precipitation mother liquor etc. Lithium extraction compound from liquid lithium resources, to replace the known β-diketone and salicylate lithium extractant, overcome the defects of existing extraction lithium technology, such as difficult synthesis of extractant, expensive, high solution loss rate.

[0034] The present application is based on the understanding and discovery of the following basic principles:

[0035] The basic principle of the action of β-diketone lithium extractant with lithium is as follows. β-diketone shows certain acidity through enol tautomerism, and forms anion under the condition of alkalinity such as hydroxyl (OH - ), carbonate (CO3 2- ), bicarbonate (HCO3 - ) and other alkalinity, thereby combining with lithium ion (Li + ) to form a neutral complex. However, when β-diketone extractant is used alone to extract lithium from aqueous solution, both the extraction effect and the separation ability from other alkali metals are very limited. At present, the effect is mainly strengthened by adding neutral phosphine synergist, and the principle of action is as follows.

[0036]

[0037] It can be seen that although β-diketone as a lithium extraction agent has three keys: 1) has strong ability to form enol structure; 2) the enol structure has strong acidity so as to react with alkalinity in lithium-containing aqueous solution to form anion; 3) has neutral phosphine hydrogen bond acceptor to strengthen the acidity of active hydrogen in enol structure and the coordination of lithium ion.

[0038] Recently reported, salicylate (phenyl salicylate, isopropyl salicylate, etc.) [Chinese patent: CN114438343A; foreign literature: Aslan Yu. Tsivadze et al., Molecules 2022, 27(10), 3051] also has the performance of extracting lithium under strong alkaline conditions, while the ester group is easy to hydrolyze and oxidize under alkaline conditions. The adjustment of alkali in the pre-lithium extraction solution and the water treatment of the post-lithium extraction solution will greatly increase the production cost, limiting its industrial application prospect.

[0039] The present inventors have found through extensive research that the structure of beta diketone and the ester group structure of salicylate are not necessary to ensure the lithium extraction performance. The hydrogen bond ring structure formed by the hydroxyl group and the ketone group is the key to coordinate with lithium ions. In the alkane structure, the hydrogen bond ring structure formed by the hydroxyl group and the ketone group is the enol structure of beta diketone. In the aromatic structure containing a benzene ring, the phenolic hydroxyl group can be used to replace the enol structure to show acidity, and when the ortho position of the phenolic hydroxyl group has a ketone group, the hydrogen bond ring structure formed by the hydroxyl group and the ketone group can also be formed.

[0040]

[0041] Compared with beta diketones, the acidic structure of the compound having the hydrogen bond ring structure of the above formula accounts for 100%, which is much higher than the proportion of the enol structure in beta diketones that coordinates with lithium. Moreover, the modification of the structure of the phenolic hydroxyl group is much easier than that of beta diketones, and can be achieved by changing R2, R3, R4, and R5. When R1 is an alkyl group or a phenyl group, it has very good stability under alkaline conditions. Moreover, the modification of R2, R3, R4, and R5 is much richer than the modification of the structure of R1 to improve the performance of the lithium extractant. In particular, when one of R2, R3, R4, and R5 is an alkoxy group, the length adjustment can be achieved by etherification of the phenolic hydroxyl group, thereby obtaining a cheap lithium extractant.

[0042] The present application discloses a kind of compound with the ability of separating lithium ions from aqueous solution, which is simple to prepare and low in price, and its structure is shown in the following formula,

[0043]

[0044] Wherein, R1 is hydrogen, C 1-8 Alkyl, C 3-6 Cycloalkyl or phenyl, said C 1-8 Alkyl, C 3-6 Cycloalkyl or phenyl is optionally substituted by one or more substituents selected from hydroxyl, halogen, C 1-6 Alkyl, phenyl, C 1-6 Alkoxy or nitro, said C 1-6 Alkyl or C 1-6 Alkoxy is optionally further substituted by one or more substituents selected from hydroxyl, halogen, C 1-6 Alkyl, C 1-6 Alkoxy or nitro;

[0045] R2, R3, R4 and R5 are each independently hydrogen, halogen, nitro, benzyloxy, C 1-6 Alkyl or C 1-16 Alkoxy, said benzyloxy, C 1-6 Alkyl or C 1-16alkyl, C 1-6 alkyl, C 1-6 alkyl, C

[0046] For example, compounds of formula (I) include, but are not limited to:

[0047]

[0048]

[0049]

[0050] In view of the economics of preparation, oil solubility, water solubility loss, availability of starting materials, and atom economy of synthesis, lithium extractants of formula (I) can be preferred by selection of R1-R5.

[0051] In one embodiment, R1is C 1-6 alkyl or phenyl, said C 1-6 alkyl or phenyl is optionally substituted with one or more substituents selected from the group consisting of hydroxy, halogen, C 1-6 alkyl, phenyl or C 1-6 alkyl, phenyl or C

[0052] In one embodiment, at least one of R2, R3, R4and R5is nitro or halogen. In a preferred embodiment, at least one of R2, R3, R4and R5is nitro. It is believed that the introduction of an electron withdrawing group such as nitro or halogen in the benzene ring increases the acidity of the phenolic hydroxyl group.

[0053] In one embodiment, one of R2, R3, R4and R5in the compound of formula (I) is benzyloxy or C 1-16 alkyl. It is believed that the introduction of benzyloxy or alkoxy groups on the benzene ring increases the oil solubility and decreases the water solubility of the compound of formula (I).

[0054] In one preferred embodiment, one of R2, R3, R4and R5in the compound of formula (I) is C 6-16 alkyl. More preferably, R4in the compound of formula (I) is C 6-16The alkoxy chain. At this point, the compound shown in formula (I) has suitable oil solubility and low water solubility, with minimal dissolution loss in aqueous solution during lithium extraction, and the raw materials are widely available and inexpensive. For example, it can be prepared by Williamson's ether synthesis reaction using 2,4-dihydroxyacetophenone or 2,4-dihydroxybenzophenone and C6-14 haloalkanes as raw materials. This preparation process has mild synthesis conditions, low raw material costs, and high yield. Preferably, the haloalkanes used are bromohexane, bromoheptane, bromon-octane, bromoisooctane, bromononane, bromodecane, bromoundecane, bromododecane, bromotridecane, bromotetradecane, bromohexadecane, benzyl chloride, and / or benzyl bromide.

[0055] Furthermore, it is possible to select the C-containing... 6-16 Based on the compound of formula (I) with an alkoxy chain, the benzene ring is modified by substituents to adjust the acidity of the phenolic hydroxyl group, thereby enabling the extraction of lithium from aqueous solutions over a wide pH range. Preferably, the modifying groups on the benzene ring include electron-withdrawing groups such as fluorine, chlorine, bromine, iodine, and nitro groups. Specifically, preferred C-containing groups are used... 6-16 The compound of formula (I) with an alkoxy chain reacts with bromine at low temperature to obtain monobrominated and / or polybrominated products, whose pKa is significantly lower than that of the unsubstituted H-type structure, thus allowing it to be used for the extraction of lithium from weakly alkaline aqueous solutions; alternatively, the preferred C-containing compound can be reacted with bromine. 6-16 The compound of formula (I) with an alkoxy chain is reacted with dilute aqueous nitric acid at a relatively low temperature to obtain mononitro and / or polynitro substituted products or mixtures thereof. The pKa is significantly lower than that of the unsubstituted H-type structure. This reaction can also be used to extract lithium from weakly alkaline aqueous solutions. The relatively low temperature is 10–70 °C.

[0056] In a preferred embodiment, R2 in the compound of formula (I) is H, nitro, or methoxy.

[0057] In a preferred embodiment, R3 in the compound of formula (I) is H, nitro, methoxy, halogen, or benzyloxy.

[0058] In a preferred embodiment, R4 in the compound of formula (I) is H, nitro, or C. 1-16 Alkyl or benzyloxy, preferably C 6-16 Alkyl group.

[0059] In a preferred embodiment, R5 in the compound of formula (I) is H, nitro, or methoxy.

[0060] In a preferred embodiment, in the compound of formula (I):

[0061] R1 is methyl, ethyl, propyl, or phenyl; and / or,

[0062] R2is hydrogen, nitro or methoxy; and / or,

[0063] R3is hydrogen, halogen, methoxy or nitro; and / or,

[0064] R4is C 1-16 alkyl, preferably C 6-16 alkyl; and / or,

[0065] R5is hydrogen, methoxy, or nitro.

[0066] The present disclosure also provides a liquid organic mixture for extraction of lithium, comprising: one or more compounds of formula (I) as described above, a synergist, and optionally a diluent. The optional diluent here means that the diluent can be present in the liquid organic mixture for extraction of lithium, or the diluent can also be absent.

[0067] In a preferred embodiment, the liquid organic mixture for extraction of lithium comprises one or more compounds of formula (I), a synergist and a diluent.

[0068] In an embodiment, the liquid organic mixture for extraction of lithium consists of one or more compounds of formula (I), a synergist and a diluent.

[0069] The compound of formula (I) and the synergist and the diluent constitute a liquid organic mixture for extraction of lithium from a lithium-containing aqueous solution, i.e. an extraction composition. The synergist is, for example, a neutral phosphine oxide, in particular one or more of tributyl phosphate, trioctyl phosphate, tris(2-ethylhexyl) phosphate, trihexyl phosphate, tripentyl phosphate, dibutyl butyl phosphate, dibutyl butyl phosphate, di-sec-octyl methyl phosphate, di-iso-octyl methyl phosphate, di-iso-octyl isopropyl phosphate, di-iso-pentyl methyl phosphate, triphenyl phosphine oxide, diphenyl benzyl phosphine oxide, diphenyl (2-hydroxyphenylmethyl) phosphine oxide, 2,5-dihydroxyphenyl (diphenyl) phosphine oxide, trioctyl phosphine oxide (or Cyanex 921), trialkyl phosphine oxide TRPO (or Cyanex 923); and the diluent is one or more of kerosene, D80 solvent oil, D60 solvent oil, n-heptane, cyclohexane, octane, dodecane, petroleum ether, xylene, anisole, methyl isobutyl ketone, toluene, octanone, 5-nonanone, isoamyl alcohol, n-butyl alcohol, halobenzene.

[0070] The addition of the synergist can enhance the acidity of the compound of formula (I) by forming hydrogen bonds with the compound of formula (I), and can also enhance the chemical stability of the extraction composition constituted by the compound of formula (I) and the synergist under the action of alkaline solution and air. The stronger the basicity of the synergist, the more significant the above effects, and therefore the preferred neutral phosphine oxide synergists are tributyl phosphine oxide, trioctyl phosphine oxide, Cyanex 923 and triphenyl phosphine oxide.

[0071] The above-mentioned liquid organic mixture for extracting lithium can be used to extract lithium from lithium-containing aqueous solution. The lithium-containing aqueous solution is a neutral or alkaline salt lake brine with low magnesium and calcium content, geothermal brine, or lithium carbonate or lithium phosphate mother liquor. In the extraction operation, the total concentration of the compound of formula (I) or mixture thereof in the extractant is 0.03-1.0 mol / L, preferably 0.05-0.2 mol / L; the concentration of the synergist in the extractant is 0.01-2.0 mol / L, preferably 0.05-0.2 mol / L; the molar ratio of the compound of formula (I) to the synergist is 3:1-0.5:1, preferably 1.5:1-0.8:1. The pH of the lithium-containing aqueous solution is 5-13, preferably 8-12.5. For alkaline natural brine, the lithium ions in the brine can be directly contacted with the organic solution containing the extractant to transfer the lithium ions into the organic solution containing the extractant. For lithium-containing aqueous solution with pH<7, the pH and alkalinity can be adjusted to 8-12.5 by adding alkali metal or ammonium hydroxide, carbonate, phosphate, or borate; or the lithium-containing aqueous solution with pH<7 can be directly contacted with the extractant saponified by sodium or potassium ions to transfer the lithium ions in the brine into the organic solution containing the extractant through the exchange of sodium or potassium ions with lithium ions.

[0072] The alkali metal or ammonium hydroxide used to adjust the pH and alkalinity of the lithium-containing aqueous solution or to saponify the extractant is one or more of sodium hydroxide, potassium hydroxide, and ammonium hydroxide; and / or the carbonate is one or more of sodium carbonate and potassium carbonate; and / or the phosphate is one or more of trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, and diammonium hydrogen phosphate; and / or the borate is one or more of sodium metaborate, potassium metaborate, ammonium metaborate, sodium tetraborate, potassium tetraborate, and ammonium tetraborate.

[0073] In the extraction operation, the volume ratio of the lithium-containing aqueous solution to the extractant is 30:1-1:30, preferably 20:1-1:5; the lithium concentration in the lithium-containing aqueous solution is 0.01-2.0 mol / L, preferably 0.02-0.5 mol / L; and the extraction temperature is -5-40℃, preferably 15-30℃.

[0074] The extraction process reaches equilibrium within 3-30 minutes, preferably 5-10 minutes, and then the remaining aqueous solution after extraction is removed by liquid-liquid separation through standing or centrifugation, and the organic solution containing the extractant loaded with lithium ions is obtained.

[0075] Further, the lithium ions are allowed to enter the stripping agent by the reaction of the stripping agent and the lithium ion loaded extractant, and the organic mixture is allowed to have the ability of extracting lithium from the lithium-containing aqueous solution again; the stripping agent is an aqueous solution of an acid, and the acid is preferably one or more of carbonic acid, sulfuric acid, sulfurous acid, hydrochloric acid, nitric acid and phosphoric acid; the concentration of hydrogen ions in the stripping agent is 0.05-6 mol / L, and preferably 0.5-3 mol / L; the concentration of hydrogen ions in the stripping agent is too low to be beneficial to the enrichment of lithium ions, and the concentration of hydrogen ions is too high to cause the stripping agent to be loaded with a large amount of acid, which affects the subsequent extraction; the volume ratio of the stripping agent to the lithium ion loaded extractant is 1:1-1:50, and preferably 1:3-1:20; after the stripping reaches equilibrium, the concentration of lithium in the stripping agent is 0.05-10 mol / L, and preferably 0.5-5 mol / L; and the reaction time between the lithium ion loaded extractant and the stripping agent is 3-30 minutes, and preferably 5-10 minutes.

[0076] The reaction between the extractant, the lithium-containing aqueous solution and / or the lithium ion stripping agent is carried out in a mixing and clarifying tank, a centrifugal extractor or an extraction column, and the extraction of lithium, the separation of lithium from sodium, potassium and the like, and the concentration of lithium can be achieved through multi-stage extraction, washing and stripping.

[0077] In order to improve the concentration of lithium ions in the stripping agent, reduce the equipment investment for subsequent concentration and reduce the production cost, concentrated acid is added to the lithium-containing stripping agent for multiple times, and then the lithium ion loaded extractant is reacted with the stripping agent again to achieve the enrichment of lithium ions in the stripping agent; the preferred concentrated acid is 6-12 mol / L hydrochloric acid, 6-18 mol / L sulfuric acid, 6-14 mol / L nitric acid or 6-15 mol / L phosphoric acid.

[0078] Further, the lithium is concentrated by evaporating water in the lithium-containing stripping agent, and then sodium carbonate, ammonium carbonate or the like is added to precipitate lithium carbonate. After the precipitation of lithium carbonate, the mother liquor can be used again to extract lithium by the extractant described in the present application.

[0079] The present disclosure includes, but is not limited to, the following embodiments:

[0080] 1. A compound of formula (I) for use as a lithium extractant,

[0081]

[0082] wherein R1 is hydrogen, C 1-8 alkyl, C 3-6 cycloalkyl or phenyl, which C 1-8 alkyl, C 3-6 cycloalkyl or phenyl is optionally substituted by one or more groups selected from hydroxy, halogen, C 1-6 alkyl, C1-6 Substitution of alkoxy or nitro groups, wherein C 1-6 Alkyl or C 1-6 Alkoxy groups may optionally be further selected from one or more hydroxyl groups, halogens, C 1-6 Alkyl, C 1-6 Substitution of alkoxy or nitro groups;

[0083] R2, R3, R4, and R5 are each independently hydrogen, halogen, nitro, benzyloxy, or C. 1-6 Alkyl or C 1-16 Alkoxy, the benzyloxy group, C 1-6 Alkyl or C 1-16 The alkoxy group is optionally surrounded by one or more elements selected from hydroxyl, halogen, C 1-6 Alkyl, C 1-6 Substitution with alkoxy or nitro groups.

[0084] 2. The compound of formula (I) as described in embodiment 1, wherein R1 is C 1-6 Alkyl or phenyl, wherein C 1-6 Alkyl or phenyl groups may be optionally selected from one or more hydroxyl, halogen, C 1-6 Alkyl, phenyl or C 1-6 Substitution of alkoxy groups.

[0085] 3. The compound of formula (I) as described in any one of embodiments 1-2, wherein at least one of R2, R3, R4 and R5 is a nitro group.

[0086] 4. The compound of formula (I) as described in any one of embodiments 1-3, wherein at least one of R2, R3, R4 and R5 is a benzyloxy group or an unsubstituted or halogenated C group. 1-16 The alkoxy group, for example, R4 is a benzyloxy group or an unsubstituted or halogenated C group. 1-16 alkoxy groups.

[0087] 5. The compound of formula (I) as described in embodiment 4, wherein at least one of R2, R3, R4 and R5 is an unsubstituted or halogenated C 6-16 The alkoxy group, preferably R4 is an unsubstituted or halogenated C4. 6-16 alkoxy groups.

[0088] 6. The compound of formula (I) as described in any one of embodiments 1-5, wherein at least one of R2, R3, R4 and R5 is a halogen.

[0089] 7. The compound of formula (I) as described in any one of embodiments 1-6, wherein R2 is H, nitro or methoxy.

[0090] 8. The compound of formula (I) according to any one of embodiments 1 to 7, wherein R3 is H, nitro, methoxy, halogen or benzyloxy.

[0091] 9. The compound of formula (I) according to any one of embodiments 1 to 8, wherein R4 is H, nitro, C 1-16 alkoxy or benzyloxy.

[0092] 10. The compound of formula (I) according to any one of embodiments 1 to 9, wherein R5 is H, nitro or methoxy.

[0093] 11. The compound of formula (I) according to any one of embodiments 1 to 10, wherein:

[0094] R1 is methyl, ethyl, propyl or phenyl; and / or,

[0095] R2 is hydrogen, nitro or methoxy; and / or,

[0096] R3 is hydrogen, halogen, methoxy or nitro; and / or,

[0097] R4 is C 1-16 alkoxy; and / or,

[0098] R5 is hydrogen, methoxy, or nitro.

[0099] 13. The compound of formula (I) according to embodiment 1, selected from:

[0100]

[0101]

[0102]

[0103] 13. Use of a compound of formula (I) according to any one of embodiments 1 to 12 as lithium extractant in the extraction of lithium.

[0104] 14. A liquid organic mixture for the extraction of lithium, comprising:

[0105] one or more compounds of formula (I) according to any one of embodiments 1 to 12,

[0106] a synergist, and

[0107] optionally a diluent.

[0108] 15. The liquid organic mixture for the extraction of lithium according to embodiment 14, wherein,

[0109] The synergist is one or more of tributyl phosphate, trioctyl phosphate, tris(2-ethylhexyl)phosphate, trihexyl phosphate, tripentyl phosphate, butylphosphoric acid dibutyl ester, butylphosphoric acid dibutyl ester, dimethylphosphoric acid di(2-sec-octyl) ester, dimethylphosphoric acid di(2-iso-octyl) ester, diisopropylphosphoric acid di(2-iso-octyl) ester, diisopropylphosphoric acid di(2-iso-pentyl) ester, triphenylphosphine oxide, diphenylbenzylphosphine oxide, diphenyl(2-hydroxyphenylmethyl)phosphine oxide, 2,5-dihydroxyphenyl(diphenyl)phosphine oxide, trioctylphosphine oxide (or Cyanex 921), trialkylphosphine oxide TRPO (or Cyanex 923).

[0110] 16. The liquid organic mixture for extraction of lithium according to any one of embodiments 14 or 15, wherein

[0111] The diluent is one or more of kerosene, D80 solvent oil, D60 solvent oil, n-heptane, cyclohexane, octane, dodecane, petroleum ether, xylene, anisole, methyl isobutyl ketone, toluene, octanone, 5-nonanone, isoamyl alcohol, n-butyl alcohol, halogenated benzene.

[0112] 17. The liquid organic mixture for extraction of lithium according to any one of embodiments 14-16, wherein the total concentration of the compound of formula (I) in the liquid organic mixture for extraction of lithium is 0.03 mol / L to 1.0 mol / L; the concentration of the synergist in the liquid organic mixture for extraction of lithium is 0.01 mol / L to 2.0 mol / L; and the molar ratio of the compound of formula (I) to the synergist is 3:1 to 0.5:1.

[0113] 18. A method for extraction of lithium, comprising:

[0114] contacting the liquid organic mixture for extraction of lithium according to any one of embodiments 14-17 with an aqueous solution containing lithium ions, allowing the lithium ions in the aqueous solution to enter the organic layer by liquid-liquid demixing, and collecting the organic layer.

[0115] 19. The method according to embodiment 18, wherein the aqueous solution containing lithium ions has a pH value of 7 to 13 before being contacted with the liquid organic mixture for extraction of lithium.

[0116] 20. The method according to embodiment 19, wherein the alkalinity of the aqueous solution containing lithium ions is adjusted by adding alkali metal or ammonium hydroxide, carbonate, phosphate, or borate.

[0117] 21. The method according to embodiment 19, wherein the aqueous solution containing lithium ions is a natural brine with alkalinity; and the alkalinity of the natural brine with alkalinity is optionally further adjusted by adding alkali metal or ammonium hydroxide, carbonate, phosphate, or borate.

[0118] 22. The method according to any one of embodiments 18-20, wherein the aqueous solution containing lithium ions is a lithium precipitation mother liquor for producing lithium carbonate and / or a lithium precipitation mother liquor for producing lithium phosphate.

[0119] 23. The method according to embodiment 20, wherein the hydroxide of alkali metal or ammonium is one or more of sodium hydroxide, potassium hydroxide and ammonium hydroxide; the carbonate is one or more of sodium carbonate and potassium carbonate; the phosphate is one or more of trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate and diammonium hydrogen phosphate; and the borate is one or more of sodium metaborate, potassium metaborate, ammonium metaborate, sodium tetraborate, potassium tetraborate and ammonium tetraborate.

[0120] 24. The method according to embodiment 18, wherein the pH value of the aqueous solution containing lithium ions before being contacted with the liquid organic mixture for lithium extraction is 5-8; and the liquid organic mixture for lithium extraction is saponified with one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate or potassium bicarbonate aqueous solution before being contacted with the aqueous solution containing lithium ions.

[0121] 25. The use according to any one of embodiments 18-24, wherein the volume ratio of the aqueous solution containing lithium ions to the liquid organic mixture for lithium extraction is 30:1-1:30; and / or the lithium concentration in the aqueous solution containing lithium ions is 0.01-2.0 mol / L.

[0122] 26. The method according to any one of embodiments 18-25, further comprising the step of contacting an eluant with the organic layer to obtain an eluant containing lithium.

[0123] 27. The method according to embodiment 26, wherein the eluant is an aqueous acid solution.

[0124] 28. The method according to embodiment 27, wherein the eluant is an aqueous solution of one or more of carbonic acid, sulfuric acid, sulfurous acid, hydrochloric acid, nitric acid and phosphoric acid; and / or the concentration of hydrogen ions in the eluant is 0.05-6 mol / L; and the volume ratio of the eluant to the organic layer is 1:1-1:50.

[0125] 29. The method according to embodiment 26, wherein the concentration of lithium in the eluant after the eluant is contacted with the organic layer is 0.05-10 mol / L.

[0126] 30. The method according to any one of embodiments 18-29, wherein the time for the liquid organic mixture for lithium extraction to be contacted with the aqueous solution containing lithium ions is 3-30 minutes.

[0127] 31. The method of embodiments 26-30, wherein the time of contact of the stripping agent with the organic layer is 3-30 minutes.

[0128] 32. The method of embodiments 18-31, wherein the contacting is performed in a mixer-settler, centrifugal contactor, or extraction column.

[0129] 33. The method of embodiments 18-32, wherein the liquid organic mixture for extraction of lithium is contacted with the same aqueous solution containing lithium one or more times.

[0130] 34. The method of embodiments 26-33, wherein concentrated acid is added to the lithium-containing stripping agent after the stripping agent has been contacted with the organic layer, and is used again to contact the organic layer with the stripping agent; the concentrated acid is 6-12 mol / L hydrochloric acid, 6-18 mol / L sulfuric acid, 6-14 mol / L nitric acid, or 6-15 mol / L phosphoric acid.

[0131] 35. The method of any one of embodiments 26-34, further comprising the operation of concentrating lithium by evaporating water in the lithium-containing stripping agent, and / or further precipitating lithium carbonate from the lithium-containing stripping agent.

[0132] Examples

[0133] The following examples are provided to further illustrate the present application. It is understood that these examples are merely illustrative of the present application and do not limit the scope of the present application. Unless otherwise indicated, the techniques and conditions used in the examples are described in the literature described in the literature or according to the product instructions. Unless otherwise indicated, the reagents or instruments used are conventional products that can be commercially available.

[0134] Example 1

[0135] Preparation of the extractant organic phase: 1 mmol of 2-hydroxybenzophenone (structure is ) and 1 mmol of trioctylphosphine oxide were added to 10 mL of cyclohexane, and the solid was shaken to completely dissolve in the liquid to form the extractant organic phase. 4 mL of lithium-containing aqueous solution B1 was added, and after shaking at 28°C for 10 min, the phases were allowed to separate, and the remaining aqueous phase R1 was discharged from the bottom. 0.2 mL of the aqueous phase was diluted to 50 mL, and the concentration of the components was detected by inductively coupled plasma spectrometer (ICP). The results are shown in the following table.

[0136] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.257 50.50 none 10.12

[0137] The extraction rates (E = (c B1- c R1 ) / c B1 × 100%, same below) were 68.2% and 10%, respectively, and the lithium / sodium separation factor (β Li / Na = (c Li / c Na ) B1-R1 / (c Li / c Na ) R1 , same below) was 19.2.

[0138] Example 2

[0139] Extraction agent organic phase configuration: 1 mmol of 2-hydroxybenzophenone (structure ) and 1 mmol of tributylphosphine oxide were added to 10 mL of cyclohexane, placed in a separatory funnel, and shaken until the solids were completely dissolved, forming the extraction agent organic phase. 4 mL of a lithium-containing aqueous solution of composition B1 were added, and after shaking for 10 min at 18°C, the phases were allowed to separate, and the remaining aqueous phase R1 was removed from the bottom. The results of the analysis are shown in the table below.

[0140] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.362 50.23 none -

[0141] The extraction efficiencies for lithium and sodium ions were 55.1% and 10.5%, respectively, and the lithium / sodium separation factor was 10.5.

[0142] Example 3

[0143] Extraction agent organic phase configuration: 0.5 mmol of 2-hydroxypropiophenone (structure ) and 1 mmol of tributylphosphine oxide were added to 10 mL of kerosene, placed in a separatory funnel, and shaken until the solids were completely dissolved, forming the extraction agent organic phase. 4 mL of a lithium-containing aqueous solution of composition B1 were added, and after shaking for 5 min, the phases were allowed to separate, and the remaining aqueous phase R1 was removed from the bottom. The results of the analysis are shown in the table below.

[0144] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.383 52.10 none -

[0145] The extraction efficiencies for lithium and sodium ions were 52.5% and 7.2%, respectively, and the lithium / sodium separation factor was 14.3.

[0146] Example 4

[0147] Extraction agent organic phase configuration: 0.5 mmol of 2-hydroxypropiophenone (structure ) and 0.5 mmol of trioctylphosphine oxide were added to 10 mL of kerosene, placed in a separatory funnel, and shaken until the solids were completely dissolved, forming the extraction agent organic phase. 4 mL of a lithium-containing aqueous solution of composition B1 were added, and after shaking for 5 min, the phases were allowed to separate, and the remaining aqueous phase R1 was removed from the bottom. The results of the analysis are shown in the table below.

[0148] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Example 1 Residual Aqueous Phase R1 0.322 53.42 none -

[0149] The extraction yields for lithium and sodium ions were 60.1% and 4.8%, respectively, and the lithium / sodium separation factor was 29.8.

[0150] Example 5

[0151] Extraction agent organic phase configuration: 1 mmol 2-hydroxypropiophenone and 2 mmol tributylphosphate were added to 10 mL kerosene, placed in a separatory funnel to form the extraction agent organic phase. 4 mL of lithium-containing aqueous solution with the following composition B1 was added, shaken for 5 min, and then allowed to separate into two phases. The remaining aqueous phase R1 at the bottom was discharged, and the results of the analysis are shown in the following table.

[0152] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.157 52.32 none -

[0153] The extraction yields for lithium and sodium ions were 80.5% and 6.8%, respectively, and the lithium / sodium separation factor was 57.0.

[0154] Example 6

[0155] Extraction agent organic phase configuration: 2 mmol 4-benzyloxy-2-hydroxyacetophenone (structure ) and 4 mmol trioctylphosphine oxide were added to 20 mL kerosene, placed in a separatory funnel to form the extraction agent organic phase. 4 mL of lithium-containing aqueous solution with the following composition B1 was added, shaken for 3 min, and then allowed to separate into two phases. The remaining aqueous phase R1 at the bottom was discharged, and the results of the analysis are shown in the following table.

[0156] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.527 55.34 none -

[0157] The extraction yields for lithium and sodium ions were 34.7% and 1.4%, respectively, and the lithium / sodium separation factor was 37.7.

[0158] Example 7

[0159] Extraction agent organic phase configuration: 1.5 mmol 4-pentyloxy-2-hydroxybenzophenone (structure ) and 1.5 mmol trioctylphosphine oxide were added to 10 mL cyclohexane, placed in a separatory funnel to form the extraction agent organic phase. 4 mL of lithium-containing aqueous solution with the following composition B1 was added, shaken for 10 min, and then allowed to separate into two phases. The remaining aqueous phase R1 at the bottom was discharged, and the results of the analysis are shown in the following table.

[0160] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.186 51.53 none -

[0161] The extraction yields for lithium and sodium ions were 77.0% and 8.2%, respectively, and the lithium / sodium separation factor was 37.5.

[0162] Example 8

[0163] Extraction agent organic phase configuration: 1 mmol of 4-hexyloxy-2- hydroxybenzophenone (structure ) and 1 mmol of trioctylphosphine oxide were added to 10 mL of D80 solvent oil in a separatory funnel to form the extraction agent organic phase. 4 mL of a lithium containing aqueous solution of composition B1 below was added and shaken for 10 minutes before allowing the phases to separate and the remaining aqueous phase R1 was removed from the bottom. The results of the analysis are shown in the table below.

[0164] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.266 52.50 none -

[0165] The extraction efficiencies for lithium and sodium ions were 67.0% and 6.5% respectively, giving a lithium / sodium separation factor of 29.5.

[0166] Example 9

[0167] Extraction agent organic phase configuration: 1 mmol of 4-heptyloxy-2- hydroxybenzophenone (structure ) and 1 mmol of tris(2-ethylhexyl)phosphate were added to 10 mL of D80 solvent oil in a separatory funnel to form the extraction agent organic phase. 4 mL of a lithium containing aqueous solution of composition B1 below was added and shaken for 10 minutes before allowing the phases to separate and the remaining aqueous phase R1 was removed from the bottom. The results of the analysis are shown in the table below.

[0168] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.316 52.65 none -

[0169] The extraction efficiencies for lithium and sodium ions were 60.8% and 6.2% respectively, giving a lithium / sodium separation factor of 23.6.

[0170] Example 10

[0171] Extraction agent organic phase configuration: 1.5 mmol of 4-n-octyloxy-2- hydroxybenzophenone (structure ) and 1.5 mmol of trioctylphosphine oxide were added to 10 mL of cyclohexane in a separatory funnel to form the extraction agent organic phase. 4 mL of a lithium containing aqueous solution of composition B2 below was added and shaken for 10 minutes before allowing the phases to separate and the remaining aqueous phase R1 was removed from the bottom. The results of the analysis are shown in the table below.

[0172] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B2 0.947 51.63 none 10.77 Remaining aqueous phase R1 0.854 49.31 none -

[0173] The extraction efficiencies for lithium and sodium ions were 9.8% and 4.5% respectively, giving a lithium / sodium separation factor of 2.3.

[0174] Example 11

[0175] Extraction agent organic phase configuration: 1.5 mmol of 4-decyloxy-2- hydroxybenzophenone (structure ) and 1.5 mmol trioctylphosphine oxide were added to 10 mL cyclohexane and placed in a separatory funnel to form the extractant organic phase. 4 mL of a lithium containing aqueous solution of composition B3 below was added and after shaking for 10 minutes, the phases were allowed to separate and the remaining aqueous phase Rl was drained from the bottom. The results are shown in the table below.

[0176] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.908 118.01 42.65 -

[0177] The extraction efficiencies for lithium and sodium ions were 3.1% and 0.9%, respectively, and the lithium / sodium separation factor was 3.5.

[0178] Example 12

[0179] Extractant organic phase configuration: 2 mmol 4-n-octyloxy-5-nitro-2-hydroxybenzophenone (structure

[0180] ) and 2 mmol trioctylphosphine oxide were added to 20 mL n-heptane and placed in a separatory funnel to form the extractant organic phase. 4 mL of a lithium containing aqueous solution of composition B3 below was added and after shaking for 10 minutes, the phases were allowed to separate and the remaining aqueous phase Rl was drained from the bottom. The results are shown in the table below.

[0181]

[0182] The extraction efficiencies for lithium, sodium and potassium ions were 85.7%, 10.1% and 8.3%, respectively, and the lithium / sodium and lithium / potassium separation factors were 53.4 and 66.0, respectively.

[0183] Example 13

[0184] Extractant organic phase configuration: 1 mmol 4-n-octyloxy-5-nitro-2-hydroxybenzophenone (structure ) and 1 mmol trioctylphosphine oxide were added to 10 mL n-heptane and placed in a separatory funnel to form the extractant organic phase. 4 mL of a lithium containing aqueous solution of composition B3 below was added and after shaking for 10 minutes, the phases were allowed to separate and the remaining aqueous phase Rl was drained from the bottom. The results are shown in the table below.

[0185] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.331 112.87 41.14 -

[0186] The extraction efficiencies for lithium, sodium and potassium ions were 64.7%, 5.2% and 4.4%, respectively, and the lithium / sodium and lithium / potassium separation factors were 33.2 and 39.9, respectively.

[0187] Example 14

[0188] Extractant organic phase configuration: 2 mmol 4-dodecyloxy 2-hydroxy-5-bromo-benzophenone (structure ) and 2 mmol trioctylphosphine oxide into 20 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of a lithium containing aqueous solution of composition B4 was added, shaken for 10 min, allowed to separate, and the remaining aqueous phase Rl was drained from the bottom. The results are shown in the table below.

[0189] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B4 0.152 34.20 2.36 9.14 Remaining aqueous phase R1 0.078 32.20 1.77 -

[0190] The extraction percentages for lithium, sodium, and potassium ions were 48.7%, 5.8%, and 25.0%, respectively, and the lithium / sodium and lithium / potassium separation factors were 15.3 and 2.8, respectively.

[0191] Example 15

[0192] Extractant organic phase configuration: 2 mmol 4-dodecyloxy-5-nitro-2- hydroxybenzophenone (structure ) and 2 mmol trioctylphosphine oxide into 20 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of a lithium containing aqueous solution of composition B4 was added, shaken for 10 min, allowed to separate, and the remaining aqueous phase Rl was drained from the bottom. The results are shown in the table below.

[0193] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B4 0.152 34.20 2.36 9.14 Remaining aqueous phase R1 0.054 31.83 1.80 -

[0194] The extraction percentages for lithium, sodium, and potassium ions were 64.5%, 6.9%, and 23.7%, respectively, and the lithium / sodium and lithium / potassium separation factors were 24.4 and 5.8, respectively.

[0195] Example 16

[0196] Extractant organic phase configuration: 2 mmol 4-n-octyloxy-3,5 dinitro-2- hydroxybenzophenone (structure ) and 2 mmol trioctylphosphine oxide into 20 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of a lithium containing aqueous solution of composition B4 was added, shaken for 10 min, allowed to separate, and the remaining aqueous phase Rl was drained from the bottom. The results are shown in the table below.

[0197] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B5 0.261 39.98 7.61 9.49 Remaining aqueous phase R1 0.030 34.90 6.89 -

[0198] The extraction percentages for lithium, sodium, and potassium ions were 88.5%, 12.7%, and 9.5%, respectively, and the lithium / sodium and lithium / potassium separation factors were 52.9 and 73.7, respectively.

[0199] Example 17

[0200] Extractant organic phase configuration: 1 mmol 4-n-octyloxy-5-nitro-2- hydroxybenzophenone (structure ) and 1 mmol 4-n-octyloxy-3,5 dinitro-2-hydroxybenzophenone (structure ) and 2 mmol trioctylphosphine oxide were added to 20 mL of kerosene and placed in a separatory funnel to form the extractant organic phase. 4 mL of a lithium containing aqueous solution of composition B5 below was added and after shaking for 10 minutes, the phases were allowed to separate and the remaining aqueous phase Rl was removed from the bottom. The results are shown in the table below.

[0201] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B5 0.261 39.98 7.61 9.49 Remaining aqueous phase R1 0.035 34.67 6.25 -

[0202] The extraction percentages for lithium, sodium and potassium ions were 86.6%, 13.3% and 17.9% respectively and the lithium / sodium and lithium / potassium separation factors were 42.2 and 29.7 respectively.

[0203] Example 18

[0204] The extractant organic phase was prepared by adding 1.5 mmol 4-n-hexadecyloxy-5-nitro-2-hydroxybenzophenone (structure ) and 0.5 mmol 4-n-hexadecyloxy-2-hydroxybenzophenone (structure ) and 0.10 mmol trioctylphosphine oxide to 20 mL of kerosene and placing in a separatory funnel to form the extractant organic phase. 4 mL of a lithium containing aqueous solution of composition B5 below was added and after shaking for 10 minutes, the phases were allowed to separate and the remaining aqueous phase Rl was removed from the bottom. The results are shown in the table below.

[0205] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B5 0.261 39.98 7.61 9.49 Remaining aqueous phase R1 0.066 35.03 6.72 -

[0206] The extraction percentages for lithium, sodium and potassium ions were 74.7%, 12.4% and 11.7% respectively and the lithium / sodium and lithium / potassium separation factors were 20.9 and 22.3 respectively.

[0207] Example 19

[0208] The equilibrium aqueous solution from Example 14 was removed and the remaining lithium loaded organic mixture was added to 2 mL of 0.6 M aqueous sulfuric acid solution. After shaking for 5 minutes, the phases were allowed to separate and the remaining aqueous phase FC1 was removed from the bottom. The results are shown in the table below.

[0209]

[0210] Example 20

[0211] The equilibrium aqueous solution from Example 16 was removed and the remaining lithium loaded organic mixture was added to 2 mL of 0.6 M aqueous sulfuric acid solution. After shaking for 3 minutes, the phases were allowed to separate and the remaining aqueous phase FC1 was removed from the bottom. The results are shown in the table below.

[0212]

[0213] Example 21

[0214] The extractant organic phase was prepared by dissolving 40 mmol of 2-hydroxyacetophenone in 80 mL of glacial acetic acid, adding 3 mL of 68 wt.% concentrated nitric acid, and reacting at 40 °C for 48 h. The product was obtained as a solid powder by evaporating the solvent at 70 °C under reduced pressure. The main component of the product was 2-hydroxy-3,5-dinitroacetophenone, which had the structure The extractant organic phase was prepared by dissolving 40 mmol of 2-hydroxyacetophenone in 80 mL of glacial acetic acid, adding 3 mL of 68 wt.% concentrated nitric acid, and reacting at 40 °C for 48 h. The product was obtained as a solid powder by evaporating the solvent at 70 °C under reduced pressure. The main component of the product was 2-hydroxy-3,5-dinitroacetophenone, which had the structure

[0215] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.098 110.09 40.85 - Back-extraction of aqueous phase FC1 0.800 3.56 0.45 Remaining aqueous phase R2 0.095 112.94 42.00 Back-extraction aqueous phase FC2 1.417 7.31 1.23 Remaining aqueous phase R3 0.099 112.25 41.74 Back-extraction aqueous phase FC3 2.046 9.52 1.48 Remaining aqueous phase R4 0.095 113.21 42.06 Back-extraction of aqueous phase FC4 2.524 10.65 1.61 Remaining aqueous phase R5 0.106 111.12 41.42 Back-extraction of aqueous phase FC5 2.959 11.13 1.64 Remaining aqueous phase R6 0.101 111.75 41.28 Back-extraction of aqueous phase FC6 3.416 12.31 2.09

[0216] Example 22

[0217] The extractant organic phase was prepared by dissolving 40 mmol of 2-hydroxyacetophenone in 80 mL of glacial acetic acid, adding 3 mL of 68 wt.% concentrated nitric acid, and reacting at 40 °C for 48 h. The product was obtained as a solid powder by evaporating the solvent at 70 °C under reduced pressure. The main component of the product was 2-hydroxy-3,5-dinitroacetophenone, which had the structure The extractant organic phase was prepared by dissolving 40 mmol of 2-hydroxyacetophenone in 80 mL of glacial acetic acid, adding 3 mL of 68 wt.% concentrated nitric acid, and reacting at 40 °C for 48 h. The product was obtained as a solid powder by evaporating the solvent at 70 °C under reduced pressure. The main component of the product was 2-hydroxy-3,5-dinitroacetophenone, which had the structure

[0218] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B5 0.947 51.63 - 10.77 Remaining aqueous phase R1 0.645 50.35 - 8.66

[0219] The extraction rates of lithium and sodium ions were 31.9% and 2.5%, respectively, and the lithium / sodium separation factor was 18.4.

[0220] Example 23

[0221] The extractant organic phase was prepared by dissolving 40 mmol of 2-hydroxyacetophenone in 80 mL of glacial acetic acid, adding 3 mL of 68 wt.% concentrated nitric acid, and reacting at 40 °C for 48 h. The product was obtained as a solid powder by evaporating the solvent at 70 °C under reduced pressure. The main component of the product was 2-hydroxy-3,5-dinitroacetophenone, which had the structure )2 mmol and 2 mmol tributylphosphine oxide were added to 20 mL of kerosene to form the extractant organic phase. 20 mL of lithium-containing aqueous solution of composition B2 was taken, 0.58 g of sodium carbonate was added, and after shaking to completely dissolve to form a clear aqueous solution, it was added to the separatory funnel containing the organic phase. After shaking for 10 min, the phases were allowed to separate, and the remaining aqueous phase R1 was discharged from the bottom. The results of the analysis are shown in the table below.

[0222]

[0223] The extraction rates for lithium and sodium ions were 80.0% and 9.5%, respectively, and the lithium / sodium separation factor was 38.1.

[0224] Example 24

[0225] The equilibrium aqueous solution in Example 12 was discharged, leaving the lithium-loaded organic mixture. After washing with 2 mL of water, 3 mL of 0.6 M aqueous sulfuric acid was added, and after shaking for 3 min, the phases were allowed to separate, and the remaining aqueous phase FC1 was discharged from the bottom. The results of the analysis are shown in the table below.

[0226]

[0227] Example 25

[0228] Extractant organic phase configuration: 20 mmol of 4-(2-ethylhexylalkoxy)-2- hydroxybenzophenone was dissolved in 40 mL of glacial acetic acid, 1.5 mL of 68 wt.% concentrated nitric acid was added, and it was reacted at 60°C for 10 h. It was evaporated to dryness under reduced pressure at 50°C to obtain the product as a solid powder (the main component structure is )2 mmol and 2 mmol tributylphosphine oxide were added to 20 mL of kerosene to form the extractant organic phase. 20 mL of lithium-containing aqueous solution of composition B2 was taken, 0.58 g of sodium carbonate was added, and after shaking to completely dissolve to form a clear aqueous solution, it was added to the separatory funnel containing the organic phase. After shaking for 10 min, the phases were allowed to separate, and the remaining aqueous phase R1 was discharged from the bottom. The results of the analysis are shown in the table below.

[0229] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B2 0.947 51.90 - 10.77 Remaining aqueous phase R1 0.616 49.71 - 8.44 Remaining aqueous phase R2 0.770 50.21 - 9.26 Remaining aqueous phase R3 0.856 51.51 - 9.61 Remaining aqueous phase FC1 3.842 2.64 - -

[0230] Example 26

[0231] The extraction and back-extraction experiment described in Example 25 was repeated 6 times. After each extraction, 0.08 mL of 10 M H2SO4 was added to the previous back-extraction solution FC1, and then back-extracted again with the acid-added FC1 to obtain lithium-rich back-extraction solution FC1. The sample analysis results are shown in the table below.

[0232] c Li (g / L) c Na (g / L) c K (g / L) pH Remaining aqueous phase FC1 19.21 14.55 - -

[0233] Example 27

[0234] Organic phase configuration of the extractant: The synthetic product in Example 25 (main component structure is as follows) 4 mmol and 8 mmol of tributylphosphine oxide were added to 40 mL of kerosene and placed in a separatory funnel to form the organic phase of the extractant. 50 mL of a lithium-containing aqueous solution with the following composition (B6) was added, and the mixture was shaken for 10 min. After standing, the phases were separated, and the remaining aqueous phase R1 at the bottom was discharged. The mixture was then washed with 4 mL of water, allowed to stand, and the remaining aqueous phase was discharged. 1.5 mL of 0.6 M H₂SO₄ aqueous solution was added, and the mixture was shaken for 5 min for back-extraction, discharging the remaining aqueous phase FC1 at the bottom. The analytical results are shown in the table below.

[0235] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B6 0.854 78.03 - 10.25 Remaining aqueous phase R1 0.483 65.88 - - Remaining aqueous phase FC1 3.324 1.92 -

[0236] Example 28

[0237] Organic phase preparation of the extractant: 1 mmol of 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (structure: 2 mmol of tri-n-octylphosphine oxide was added to 10 mL of cyclohexane and placed in a separatory funnel. The mixture was shaken to completely dissolve the solid, forming the organic phase of the extractant. 4 mL of a lithium-containing aqueous solution with the following composition B1 was added. After shaking at 18 °C for 10 min, the mixture was allowed to stand for phase separation. The remaining aqueous phase R1 at the bottom was discharged, and the analytical results are shown in the table below.

[0238] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.132 54.23 none -

[0239] The extraction rates for lithium and sodium ions were 83.6% and 3.4%, respectively, with a lithium / sodium separation factor of 146.7.

[0240] Example 29

[0241] Organic phase preparation of the extractant: 1 mmol of 2-hydroxybenzophenone (structure: ) and 1 mmol tri-n-octylphosphine oxide into 10 mL cyclohexane, placed in a separatory funnel, shaken to completely dissolve the solid, forming the extractant organic phase. Added 4 mL 0.5 mol / L aqueous NaOH solution, shaken for 30 min, then allowed to stand to separate into two phases, and the remaining aqueous phase at the bottom was discharged. Added the lithium-containing aqueous solution of B2, shaken for 10 min at room temperature, then allowed to stand to separate into two phases, and the remaining aqueous phase R1 at the bottom was discharged. The analysis results are shown in the following table.

[0242] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B2 0.947 51.63 none 10.77 Remaining aqueous phase R1 0.214 49.31 none -

[0243] The extraction rates of lithium and sodium ions were 73.3% and 2.32%, respectively, and the lithium / sodium separation factor was 72.8.

[0244] Example 30

[0245] Extractant organic phase configuration: 1 mmol 2-hydroxy-5-methoxyacetophenone (structure is ) and 1 mmol tri-n-octylphosphine oxide were added to 10 mL n-heptane, placed in a separatory funnel, forming the extractant organic phase. Added 4 mL lithium-containing aqueous solution of B7 with the following composition, shaken for 10 min at 26°C, then allowed to stand to separate into two phases, and the remaining aqueous phase R1 at the bottom was discharged. The analysis results are shown in the following table.

[0246] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.331 49.56 4.99 10.30

[0247] The extraction rates of lithium, sodium, and potassium ions were 60.26%, 10.86%, and 7.08%, respectively, and the lithium / sodium separation factor was 12.4.

[0248] Example 31

[0249] Extractant organic phase configuration: 1 mmol 2-hydroxy-6-methoxyacetophenone (structure is ) and 1 mmol tri-n-octylphosphine oxide were added to 10 mL n-heptane, placed in a separatory funnel, forming the extractant organic phase. Added 4 mL lithium-containing aqueous solution of B7 with the following composition, shaken for 10 min at 26°C, then allowed to stand to separate into two phases, and the remaining aqueous phase R1 at the bottom was discharged. The analysis results are shown in the following table.

[0250] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.388 50.11 5.20 -

[0251] The extraction rates of lithium, sodium, and potassium ions were 53.42%, 9.86%, and 3.2%, respectively, and the lithium / sodium separation factor was 10.5.

[0252] Example 32

[0253] Extractant organic phase configuration: 1 mmol 2-hydroxy-5-benzyloxyacetophenone (structure is ) and 1 mmol trioctylphosphine oxide into 10 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of lithium containing aqueous solution of composition B7 below was added, shaken for 10 min at 26°C, allowed to settle and separate into phases, and the remaining aqueous phase R1 was drained from the bottom. The results of the analysis are shown in the table below.

[0254] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.445 51.26 5.01 -

[0255] The extraction efficiencies for lithium, sodium, and potassium ions were 46.6%, 7.8%, and 6.7%, respectively, and the lithium / sodium separation factor was 10.3.

[0256] Example 33

[0257] Extractant organic phase configuration: 1 mmol 2-hydroxy-3,4-dimethoxyacetophenone (structure ) and 1 mmol trioctylphosphine oxide were added to 10 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of lithium containing aqueous solution of composition B7 below was added, shaken for 10 min at 26°C, allowed to settle and separate into phases, and the remaining aqueous phase R1 was drained from the bottom. The results of the analysis are shown in the table below.

[0258] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.416 48.96 4.95 -

[0259] The extraction efficiencies for lithium, sodium, and potassium ions were 50.06%, 11.94%, and 7.8%, respectively, and the lithium / sodium separation factor was 7.4.

[0260] Example 34

[0261] Extractant organic phase configuration: 1 mmol 2-hydroxy-3-nitroacetophenone (structure ) and 1 mmol trioctylphosphine oxide were added to 10 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of lithium containing aqueous solution of composition B7 below was added, shaken for 10 min at 26°C, allowed to settle and separate into phases, and the remaining aqueous phase R1 was drained from the bottom. The results of the analysis are shown in the table below.

[0262] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.056 51.06 5.12 -

[0263] The extraction efficiencies for lithium, sodium, and potassium ions were 93.28%, 8.17%, and 4.5%, respectively, and the lithium / sodium separation factor was 156.

[0264] Example 35

[0265] Extractant organic phase configuration: 1 mmol 2-hydroxy-4-nitroacetophenone (structure ) and 1 mmol trioctylphosphine oxide into 10 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of lithium containing aqueous solution of composition B7 below was added, shaken for 10 minutes at 26°C, allowed to settle and separate into phases, and the remaining aqueous phase Rl was drained from the bottom. The results of the analysis are shown in the table below.

[0266] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.069 51.66 5.21 -

[0267] The extraction efficiencies for lithium, sodium, and potassium ions were 91.72%, 7.09%, and 3.0%, respectively, and the lithium / sodium separation factor was 145.

[0268] Example 36

[0269] Extractant organic phase configuration: 1 mmol 2-hydroxy-6-nitroacetophenone (structure ) and 0.8 mmol trioctylphosphine oxide were added to 10 mL of n-heptane, placed in a separatory funnel to form the extractant organic phase. 5 mL of lithium containing aqueous solution of composition B7 below was added, shaken for 10 minutes at 26°C, allowed to settle and separate into phases, and the remaining aqueous phase Rl was drained from the bottom. The results of the analysis are shown in the table below.

[0270] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.157 51.03 4.87 -

[0271] The extraction efficiencies for lithium, sodium, and potassium ions were 81.1%, 8.2%, and 9.3%, respectively, and the lithium / sodium separation factor was 48.

[0272] Example 37

[0273] Extractant organic phase configuration: 1 mmol 5-chloro-2-hydroxy-3-nitroacetophenone (structure ) and 0.8 mmol trioctylphosphine oxide were added to 10 mL of D80 solvent oil, placed in a separatory funnel to form the extractant organic phase. 5 mL of lithium containing aqueous solution of composition B7 below was added, shaken for 10 minutes at 26°C, allowed to settle and separate into phases, and the remaining aqueous phase Rl was drained from the bottom. The results of the analysis are shown in the table below.

[0274] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.066 50.76 4.93 -

[0275] The extraction efficiencies for lithium, sodium, and potassium ions were 92.1%, 8.7%, and 9.2%, respectively, and the lithium / sodium separation factor was 120.

[0276] Example 38

[0277] Extractant organic phase configuration: 1 mmol 2-hydroxy-5-chlorobenzophenone (structure ) and 1 mmol trioctylphosphine oxide into 10 mL D60 solvent oil, placed in a separatory funnel to form the extractant organic phase. Add 5 mL of lithium-containing aqueous solution of B7 composition as follows, shake at 26°C for 10 min, then stand to separate the phases, and release the remaining aqueous phase R1 at the bottom, the analysis results are as follows.

[0278] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.366 50.81 4.99 -

[0279] The extraction rates of lithium, sodium, and potassium ions are 56.06%, 8.7%, and 7.1%, respectively, and the lithium / sodium separation factor is 13.5.

[0280] Example 39

[0281] Extractant organic phase configuration: add 1 mmol 2-hydroxy-5-iodoacetophenone (structure is ) and 1 mmol trioctylphosphine oxide into 10 mL D60 solvent oil, placed in a separatory funnel to form the extractant organic phase. Add 5 mL of lithium-containing aqueous solution of B7 composition as follows, shake at 26°C for 10 min, then stand to separate the phases, and release the remaining aqueous phase R1 at the bottom, the analysis results are as follows.

[0282] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.432 49.86 4.91 -

[0283] The extraction rates of lithium, sodium, and potassium ions are 48%, 10.3%, and 8.5%, respectively, and the lithium / sodium separation factor is 8.

[0284] Example 40

[0285] Extractant organic phase configuration: add 1 mmol 2-hydroxy-5-fluoroacetophenone (structure is ) and 1 mmol trioctylphosphine oxide into 10 mL D60 solvent oil, placed in a separatory funnel to form the extractant organic phase. Add 5 mL of lithium-containing aqueous solution of B7 composition as follows, shake at 26°C for 10 min, then stand to separate the phases, and release the remaining aqueous phase R1 at the bottom, the analysis results are as follows.

[0286] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B7 0.833 55.60 5.37 12.05 Remaining aqueous phase R1 0.417 49.81 4.86 -

[0287] The extraction rates of lithium, sodium, and potassium ions are 50%, 10.4%, and 9.5%, respectively, and the lithium / sodium separation factor is 8.6.

[0288] Example 41

[0289] Extractant organic phase configuration: add 1 mmol 2-hydroxy-2-phenylacetophenone (structure is ) and 1 mmol trioctylphosphine oxide into 10 mL cyclohexane, put into a separatory funnel, shake to make the solid completely dissolved, form the extractant organic phase. Add 4 mL lithium-containing aqueous solution of B1, shake at 28°C for 10 min, then stand to separate the phases, release the remaining aqueous phase R1 at the bottom, take 0.2 mL diluted to 50 mL, then use an inductively coupled plasma spectrometer (ICP) to detect the concentration of components (the detection method of subsequent examples is the same), the results are as follows.

[0290] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.248 49.50 none 10.1

[0291] The extraction rates of lithium and sodium ions (E = (c B1 -c R1 ) / c B1 × 100%, same below) are 69.3% and 11.8% respectively, and the lithium / sodium separation factor is 16.8.

[0292] Comparative Example 1: (β-diketone: benzoylacetone)

[0293] Extractant organic phase configuration: 0.5 mmol benzoylacetone and 0.5 mmol tri-n-octylphosphine oxide are added to 10 mL cyclohexane, put into a separatory funnel, shake to make the solid completely dissolved, form the extractant organic phase. Add 4 mL lithium-containing aqueous solution of B3, shake at room temperature for 10 min, then stand to separate the phases, release the remaining aqueous phase R1 at the bottom, and the analysis results are as follows.

[0294] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.440 112.63 41.79 -

[0295] The extraction rates of lithium and sodium ions are 53.0% and 5.43% respectively, and the lithium / sodium separation factor is 19.6.

[0296] Comparative Example 2: (β-diketone: benzoylacetone)

[0297] Extractant organic phase configuration: 0.5 mmol benzoylacetone and 0.5 mmol tri-n-octylphosphine oxide are added to 10 mL cyclohexane, put into a separatory funnel, shake to make the solid completely dissolved, form the extractant organic phase. Add 4 mL lithium-containing aqueous solution of B5, shake at room temperature for 10 min, then stand to separate the phases, release the remaining aqueous phase R1 at the bottom, and the analysis results are as follows.

[0298] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B5 0.261 39.98 7.61 9.49 Remaining aqueous phase R1 0.200 38.20 7.52 -

[0299] The extraction rates of lithium and sodium ions are 23.4% and 4.45% respectively, and the lithium / sodium separation factor is 6.54.

[0300] Comparative Example 3: (β-diketone: 1,3-diphenyl-1,3-propanedione)

[0301] Extraction organic phase configuration: 0.5 mmol 1,3-diphenyl-1,3- propanedione and 0.5 mmol tri-n-octylphosphine oxide were added to 10 mL cyclohexane in a separatory funnel, shaken to completely dissolve the solids, forming the extraction organic phase. 4 mL of the lithium containing aqueous solution of B3 was added, shaken for 10 minutes at room temperature, allowed to settle and separate, and the remaining aqueous phase R1 was drained from the bottom. The results of the analysis are shown in the table below.

[0302] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.377 115.32 43.21 -

[0303] The extraction percentages for lithium and sodium ions were 59.76% and 3.17%, respectively, and the lithium / sodium separation factor was 45.3.

[0304] Comparative Example 4: (β-diketone: 1,3-diphenyl-1,3-propanedione)

[0305] Extraction organic phase configuration: 0.5 mmol 1,3-diphenyl-1,3- propanedione and 0.5 mmol tri-n-octylphosphine oxide were added to 10 mL cyclohexane in a separatory funnel, shaken to completely dissolve the solids, forming the extraction organic phase. 4 mL of the lithium containing aqueous solution of B5 was added, shaken for 10 minutes at room temperature, allowed to settle and separate, and the remaining aqueous phase R1 was drained from the bottom. The results of the analysis are shown in the table below.

[0306] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.261 39.98 7.61 9.49 Remaining aqueous phase R1 0.186 38.12 7.60 -

[0307] The extraction percentages for lithium and sodium ions were 28.73% and 4.65%, respectively, and the lithium / sodium separation factor was 8.3.

[0308] Comparative Example 5: (β-diketone: stearoylbenzoylmethane)

[0309] Extraction organic phase configuration: 0.5 mmol stearoylbenzoylmethane and 0.5 mmol tri-n-octylphosphine oxide were added to 10 mL cyclohexane in a separatory funnel, shaken to completely dissolve the solids, forming the extraction organic phase. 4 mL of the lithium containing aqueous solution of B3 was added, shaken for 10 minutes at room temperature, allowed to settle and separate, and the remaining aqueous phase R1 was drained from the bottom. The results of the analysis are shown in the table below.

[0310] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.577 113.57 41.03 -

[0311] The extraction percentages for lithium and sodium ions were 38.42% and 4.64%, respectively, and the lithium / sodium separation factor was 12.8.

[0312] Comparative Example 6: (fluorine containing β-diketone: 4,4,4-trifluoro-1-(4- tolyl)-1,3-butanedione)

[0313] Extraction agent organic phase configuration: 0.5 mmol 4,4,4-trifluoro-l-(4- methylphenyl)-l,3-butanedione and 0.5 mmol tri-n-octylphosphine oxide were added to 10 mL cyclohexane in a separatory funnel, shaken to completely dissolve the solids, forming the extraction agent organic phase. 4 mL of the lithium-containing aqueous solution of B3 was added, shaken for 10 minutes at room temperature, allowed to settle and separate, and the remaining aqueous phase Rl was drained from the bottom. The results of the analysis are shown in the table below.

[0314] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.177 115.17 42.11 -

[0315] The extraction efficiencies for lithium and sodium ions were 81.11% and 3.30%, respectively, and the lithium / sodium separation factor was 125.8.

[0316] Comparative Example 7: (l-phenyl-3-methyl-4-benzoyl-5-pyrazolone)

[0317] Extraction agent organic phase configuration: 1 mmol l-phenyl-3-methyl-4- benzoyl-5-pyrazolone and 1 mmol tri-n-octylphosphine oxide were added to 10 mL cyclohexane in a separatory funnel, shaken to completely dissolve the solids, forming the extraction agent organic phase. 4 mL of the lithium-containing aqueous solution of B3 was added, shaken for 10 minutes at room temperature, allowed to settle and separate, and the remaining aqueous phase Rl was drained from the bottom. The results of the analysis are shown in the table below.

[0318] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B3 0.937 119.10 43.03 9.60 Remaining aqueous phase R1 0.925 117.80 42.96 -

[0319] The extraction efficiencies for lithium and sodium ions were 1.28% and 1.09%, respectively, and the lithium / sodium separation factor was 1.17.

[0320] Comparative Example 8: (l-phenyl-3-methyl-4-benzoyl-5-pyrazolone)

[0321] Extraction agent organic phase configuration: 1 mmol l-phenyl-3-methyl-4- benzoyl-5-pyrazolone and 1 mmol tri-n-octylphosphine oxide were added to 10 mL cyclohexane in a separatory funnel, shaken to completely dissolve the solids, forming the extraction agent organic phase. 4 mL of the lithium-containing aqueous solution of B3 was added, shaken for 10 minutes at room temperature, allowed to settle and separate, and the remaining aqueous phase Rl was drained from the bottom. The results of the analysis are shown in the table below.

[0322] c Li (g / L) c Na (g / L) c K (g / L) pH Lithium-containing solution B1 0.807 56.12 none 11.48 Remaining aqueous phase R1 0.747 53.65 none -

[0323] The extraction efficiencies for lithium and sodium ions were 7.43% and 4.40%, respectively, and the lithium / sodium separation factor was 1.74.

[0324] Comparing the control example and the embodiment, it can be found that the structure proposed in the present application can well achieve the effect of replacing the lithium extraction agent of β-diketone. When the benzene ring of the compound of formula (I) is not substituted, the effect is equivalent to that of β-diketone without trifluoromethyl, and a high lithium extraction rate is often obtained under high alkaline conditions, but the former has a lower manufacturing cost; and when the benzene ring of the compound of formula (I) is partially substituted with halogen or nitro, the effect can be equivalent to that of β-diketone with trifluoromethyl, and a high lithium extraction rate can be obtained even under lower alkaline conditions, but the manufacturing cost of the former is still much lower than that of the latter. Therefore, the change of the substituents R1-R5 in the compound of formula (I) of the present application will significantly affect its lithium extraction capacity, lithium / sodium, lithium / potassium separation capacity, alkalinity required for lithium extraction, raw material cost, and process cost.

[0325] Dissolution loss rate

[0326] The dissolution loss rate is evaluated by the solubility in water. The solubility in pure water at room temperature (the solubility of the lithium extraction agent of the present application is determined by ultraviolet-visible absorption spectrometry; the data of the control example is derived from the public literature www.chemicalbook.com):

[0327] 4-n-octyloxy-3-nitro-2-hydroxybenzophenone 0.01 g / L

[0328] 4-n-octyloxy-2-hydroxybenzophenone <0.01 g / L

[0329] 4-pentyloxy-2-hydroxybenzophenone 0.05 g / L

[0330] Salicylaldehyde (structure is ) solubility 4.9 g / L

[0331] 2-hydroxyacetophenone (structure is ) solubility 0.2 g / L

[0332] 2,4-dihydroxybenzophenone (structure is ) solubility 0.7 g / L [J. Chem. Eng. Data 2008, 53, 8, 1996-1998]

[0333] 2-hydroxy-4-methoxybenzophenone (structure ) solubility <1.0 g / L

[0334] 2-hydroxy-4-octyloxy-5-nitrobenzophenone (structure ) solubility 0.01 g / L

[0335] Control example: benzoyltrifluoropropenone (β-diketone) 0.24 g / L

[0336] Comparative Example: benzoylacetone (β-diketone) 0.38 g / L

[0337] As can be seen from the example, the dissolution loss of the typical lithium extraction agent in the present disclosure is far lower than that of the β-diketone, and in particular, the solubility of 4-n-octyloxy-5-nitro-2-hydroxybenzophenone, which is equivalent to benzoyl trifluoroacetone in lithium extraction effect, in pure water is extremely low, and is 2 orders of magnitude lower than the solubility of benzoyl trifluoroacetone.

[0338] The above merely describes exemplary embodiments of the present application, but is not intended to limit the protection scope of the present application, which is defined by the appended claims.

Claims

1. The use of liquid organic mixtures as lithium extraction agents in lithium extraction, wherein, The liquid organic mixture comprises: One or more compounds of formula (I), (I) Wherein, R1 is hydrogen, C 1-8 Alkyl or phenyl, wherein the phenyl group is optionally oxidized by one or more radicals selected from hydroxyl, C 1-6 Alkyl and C 1-6 Substitution of alkoxy groups; R2, R3, R4, and R5 are each independently hydrogen, halogen, nitro, benzyloxy, or C. 1-6 Alkyl or C 1-16 Alkoxy Synergist, wherein the synergist is a neutral phosphine oxide, and Optional diluent.

2. The use as described in claim 1, wherein, R1 is C 1-6 Alkyl or phenyl, wherein the phenyl group is optionally substituted with one or more radicals selected from hydroxyl, C 1-6 Alkyl and C 1-6 Substitution of alkoxy groups.

3. The use as described in claim 1, wherein, At least one of R2, R3, R4, and R5 is a nitro group.

4. The use as described in claim 1, wherein, R2, R3, R4, and R5 must all be benzyloxy or C 1-16 Alkyl group.

5. The use as described in claim 4, wherein, At least one of R2, R3, R4, and R5 is C. 6-16 alkoxy groups.

6. The use as described in claim 1, wherein, At least one of R2, R3, R4, and R5 is a halogen.

7. The use as described in claim 1, wherein, R2 is H, nitro, or methoxy.

8. The use as described in claim 1, wherein, R3 can be H, nitro, methoxy, halogen, or benzyloxy.

9. The use as described in claim 1, wherein, R4 represents H, nitro, and C. 1-16 Alkyl or benzyloxy.

10. The use as described in claim 1, wherein, R5 can be H, nitro, or methoxy.

11. The use as described in claim 1, wherein: R1 is methyl, ethyl, propyl, or phenyl; and / or, The R2 is hydrogen, nitro, or methoxy; and / or, The R3 is hydrogen, halogen, methoxy, or nitro; and / or, R4 is C 1-16 alkoxy groups; and / or, R5 is hydrogen, methoxy, or nitro.

12. The use as described in claim 1, wherein the compound of formula (I) is selected from: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 , and .

13. The use as described in any one of claims 1-12, wherein, The synergist is one or more of the following: tributyl phosphate, trioctyl phosphate, tri(2-ethylhexyl) phosphate, trihexyl phosphate, tripentyl phosphate, dibutyl butyl phosphate, dibutyl butyl phosphate, di-2-octyl methyl phosphate, diisooctyl methyl phosphate, diisooctyl methyl phosphate, diisopentyl methyl phosphate, triphenylphosphine oxide, diphenylbenzylphosphine oxide, diphenyl(2-hydroxyphenylmethyl)phosphine oxide, 2,5-dihydroxyphenyl(diphenyl)phosphine oxide, trioctylphosphine oxide (Cyanex921), and trialkylphosphine oxide TRPO (Cyanex923). The diluent is one or more of the following: kerosene, D80 solvent oil, D60 solvent oil, n-heptane, cyclohexane, octane, dodecane, petroleum ether, xylene, anisole, methyl isobutyl ketone, toluene, octanone, 5-nonanone, isoamyl alcohol, n-butanol, and halobenzene.

14. A liquid organic mixture for lithium extraction, comprising: One or more compounds of formula (I): (I) in, R1 is hydrogen, C 1-8 Alkyl or phenyl, wherein the phenyl group is optionally oxidized by one or more radicals selected from hydroxyl, C 1-6 Alkyl and C 1-6 Substitution of alkoxy groups; R2, R3, R4, and R5 are each independently hydrogen, halogen, nitro, benzyloxy, or C. 1-6 Alkyl or C 1-16 Alkoxy The synergist, wherein the synergist is one or more selected from the following: tributyl phosphate, trioctyl phosphate, tri(2-ethylhexyl) phosphate, trihexyl phosphate, tripentyl phosphate, dibutyl butyl phosphate, dibutyl butyl phosphate, di-sec-octyl methyl phosphate, diisooctyl methyl phosphate, diisooctyl methyl phosphate, diisopentyl methyl phosphate, triphenylphosphine oxide, diphenylbenzylphosphine oxide, diphenyl(2-hydroxyphenylmethyl)phosphine oxide, 2,5-dihydroxyphenyl(diphenyl)phosphine oxide, trioctylphosphine oxide (Cyanex921), and trialkylphosphine oxide TRPO (Cyanex923). Optional diluent, wherein the diluent is one or more selected from kerosene, D80 solvent oil, D60 solvent oil, n-heptane, cyclohexane, octane, dodecane, petroleum ether, xylene, anisole, methyl isobutyl ketone, toluene, octanone, 5-nonanone, isoamyl alcohol, n-butanol, and halobenzene.

15. The liquid organic mixture for lithium extraction as described in claim 14, wherein, R1 is C 1-6 Alkyl or phenyl, wherein the phenyl group is optionally substituted with one or more radicals selected from hydroxyl, C 1-6 Alkyl or C 1-6 Substitution of alkoxy groups.

16. The liquid organic mixture for lithium extraction as described in claim 14, wherein, At least one of R2, R3, R4, and R5 is a nitro group.

17. The liquid organic mixture for lithium extraction as described in claim 14, wherein, R2, R3, R4, and R5 must all be benzyloxy or C 1-16 Alkyl group.

18. The liquid organic mixture for lithium extraction as described in claim 14, wherein, R2, R3, R4, and R5 must each be an unsubstituted or halogenated C3. 6-16 alkoxy groups.

19. The liquid organic mixture for lithium extraction as described in claim 14, wherein, At least one of R2, R3, R4, and R5 is a halogen.

20. The liquid organic mixture for lithium extraction as described in claim 14, wherein, R2 is H, nitro, or methoxy.

21. The liquid organic mixture for lithium extraction as described in claim 14, wherein, R3 can be H, nitro, methoxy, halogen, or benzyloxy.

22. The liquid organic mixture for lithium extraction as described in claim 14, wherein, R4 represents H, nitro, and C. 1-16 Alkyl or benzyloxy.

23. The liquid organic mixture for lithium extraction as described in claim 14, wherein, R5 can be H, nitro, or methoxy.

24. The liquid organic mixture for lithium extraction as described in claim 14, wherein: R1 is methyl, ethyl, propyl, or phenyl; and / or, The R2 is hydrogen, nitro, or methoxy; and / or, The R3 is hydrogen, halogen, methoxy, or nitro; and / or, R4 is C 1-16 alkoxy groups; and / or, R5 is hydrogen, methoxy, or nitro.

25. The liquid organic mixture for lithium extraction as described in claim 14, wherein, The compound of formula (I) is selected from: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 , , , and .

26. The liquid organic mixture for lithium extraction as described in claim 14, wherein, The concentration of the compound of formula (I) in the liquid organic mixture used for lithium extraction is 0.03 mol / L to 1.0 mol / L; The concentration of the synergist in the liquid organic mixture used for lithium extraction is 0.01 mol / L to 2.0 mol / L; The molar ratio of the compound of formula (I) to the synergist is 3:1 to 0.5:

1.

27. A method for extracting lithium, comprising: The liquid organic mixture for lithium extraction as described in any one of claims 14-26 is brought into contact with an aqueous solution containing lithium ions. Through liquid-liquid separation, lithium ions in the aqueous solution enter the organic layer, and the organic layer is collected.

28. The method of claim 27, wherein, The aqueous solution containing lithium ions has a pH of 7 to 13 before contacting the liquid organic mixture for lithium extraction.

29. The method of claim 28, wherein, The alkalinity of the aqueous solution containing lithium ions is adjusted by adding alkali metal or ammonium hydroxides, carbonates, phosphates, or borates.

30. The method of claim 28, wherein, The lithium-ion-containing aqueous solution is an alkaline natural brine; the alkalinity of the alkaline natural brine may optionally be further adjusted by adding alkali metal or ammonium hydroxides, carbonates, phosphates, or borates.

31. The method of claim 28, wherein, The aqueous solution containing lithium ions is a lithium precipitation mother liquor for the production of lithium carbonate and / or a lithium precipitation mother liquor for the production of lithium phosphate.

32. The method of claim 29, wherein, The hydroxide of the alkali metal or ammonium is one or more of sodium hydroxide, potassium hydroxide, and ammonium hydroxide; The carbonate is one or more of sodium carbonate and potassium carbonate; The phosphate is one or more of trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, and diammonium hydrogen phosphate; The borate is one or more selected from sodium metaborate, potassium metaborate, ammonium metaborate, sodium tetraborate, potassium tetraborate, and ammonium tetraborate.

33. The method of claim 27, wherein, The pH value of the lithium-ion-containing aqueous solution is 5 to 8 before it comes into contact with the liquid organic mixture for lithium extraction. The liquid organic mixture used for lithium extraction is saponified with one or more of the following aqueous solutions: sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, or potassium bicarbonate, before being brought into contact with the aqueous solution containing lithium ions.

34. The method according to any one of claims 27-33, wherein, The volume ratio of the lithium-ion-containing aqueous solution to the liquid organic mixture used for lithium extraction is 30:1 to 1:30; and / or, The lithium concentration in the aqueous solution containing lithium ions is 0.01 mol / L to 2.0 mol / L.

35. The method of any one of claims 27-33, further comprising the step of contacting the desorbent with the organic layer to obtain a lithium-containing desorbent.

36. The method of claim 35, wherein, The stripping agent is an aqueous solution of acid.

37. The method of claim 36, wherein, The stripping agent is an aqueous solution of one or more of the following: carbonic acid, sulfuric acid, sulfurous acid, hydrochloric acid, nitric acid, and phosphoric acid; and / or, In the desorption agent, the concentration of hydrogen ions is 0.05 mol / L to 6 mol / L; The volume ratio of the desiccant to the organic layer is 1:1 to 1:

50.

38. The method of claim 35, wherein, After the descaling agent comes into contact with the organic layer, the lithium concentration in the lithium-containing descaling agent is 0.05 mol / L to 10 mol / L.

39. The method according to any one of claims 27-33, wherein, The contact time between the liquid organic mixture used for lithium extraction and the aqueous solution containing lithium ions is 3 to 30 minutes.

40. The method of claim 35, wherein, The contact time between the desiccant and the organic layer is 3 to 30 minutes.

41. The method according to any one of claims 27-33, wherein, The contact is carried out in a mixing and clarification tank, a centrifugal extractor, or an extraction tower.

42. The method according to any one of claims 27-33, wherein, The liquid organic mixture used for lithium extraction is contacted once or multiple times with the same aqueous solution containing lithium ions.

43. The method of claim 35, wherein, After the desiccant comes into contact with the organic layer, concentrated acid is added to the lithium-containing desiccant, which is then used as a desiccant to come into contact with the organic layer again. The concentrated acid is 6-12 mol / L hydrochloric acid, 6-18 mol / L sulfuric acid, 6-14 mol / L nitric acid, or 6-15 mol / L phosphoric acid.

44. The method of claim 43, further comprising the operation of concentrating lithium by evaporating water in the lithium-containing extractant, and / or further precipitating lithium carbonate from the lithium-containing extractant.

45. The use of liquid organic mixtures as lithium extraction agents in lithium extraction, wherein, The liquid mixture comprises: Selected from one or more of the following compounds: 、 、 ,and ; Synergist, wherein the synergist is a neutral phosphine oxide; and Optional diluent.

46. ​​The use as described in claim 45, wherein: The synergist is one or more of the following: tributyl phosphate, trioctyl phosphate, tri(2-ethylhexyl) phosphate, trihexyl phosphate, tripentyl phosphate, dibutyl butyl phosphate, dibutyl butyl phosphate, di-sec-octyl methyl phosphate, diisooctyl methyl phosphate, diisooctyl methyl phosphate, diisopentyl methyl phosphate, triphenylphosphine oxide, diphenylbenzylphosphine oxide, diphenyl(2-hydroxyphenylmethyl)phosphine oxide, 2,5-dihydroxyphenyl(diphenyl)phosphine oxide, trioctylphosphine oxide, and trialkylphosphine oxide (TRPO). The diluent is one or more of the following: kerosene, D80 solvent oil, D60 solvent oil, n-heptane, cyclohexane, octane, dodecane, petroleum ether, xylene, anisole, methyl isobutyl ketone, toluene, octanone, 5-nonanone, isoamyl alcohol, n-butanol, and halobenzene.

47. A liquid organic mixture for lithium extraction, comprising: Selected from one or more of the following compounds: 、 、 ,and ; Synergists, among which, The synergist is one or more of the following: tributyl phosphate, trioctyl phosphate, tri(2-ethylhexyl) phosphate, trihexyl phosphate, tripentyl phosphate, dibutyl butyl phosphate, dibutyl butyl phosphate, di-2-octyl methyl phosphate, diisooctyl methyl phosphate, diisooctyl methyl phosphate, diisopentyl methyl phosphate, triphenylphosphine oxide, diphenylbenzylphosphine oxide, diphenyl(2-hydroxyphenylmethyl)phosphine oxide, 2,5-dihydroxyphenyl(diphenyl)phosphine oxide, trioctylphosphine oxide, and trialkylphosphine oxide (TRPO); and The diluent is one or more of the following: kerosene, D80 solvent oil, D60 solvent oil, n-heptane, cyclohexane, octane, dodecane, petroleum ether, xylene, anisole, methyl isobutyl ketone, toluene, octanone, 5-nonanone, isoamyl alcohol, n-butanol, and halobenzene.

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