CN107619951B

CN107619951B - Extraction composition, extraction system and application thereof

Info

Publication number: CN107619951B
Application number: CN201610561645.1A
Authority: CN
Inventors: 袁承业; 李晋峰
Original assignee: Shanghai Institute of Organic Chemistry of CAS
Current assignee: Shanghai Institute of Organic Chemistry of CAS
Priority date: 2016-07-15
Filing date: 2016-07-15
Publication date: 2020-12-29
Anticipated expiration: 2036-07-15
Also published as: CN107619951A

Abstract

The invention discloses an extraction composition and an extractionA system and an application thereof. The extraction composition comprises an extracting agent and a neutral phosphorus-oxygen compound shown as a formula A; the extractant comprises N, N-di (2-ethylhexyl) propionamide but does not comprise N, N-di (2-ethylhexyl) acetamide. According to the invention, the mixture of the amide compound with a specific structure and the neutral phosphorus-oxygen compound is selected as the extracting agent, so that the extraction rate of Li in the lithium-containing brine is up to 91.69%; the distribution coefficient of lithium and magnesium is up to 823; when the HCl is used for back extraction of lithium, the back extraction rate is 84.58-90.40%, the extraction and back extraction performance of lithium salt extracted from lithium-containing brine is greatly improved, the cost is saved, and the method is more suitable for industrial production.

Description

Extraction composition, extraction system and application thereof

Technical Field

The invention relates to an extraction composition, an extraction system and application thereof.

Background

Lithium has important applications not only in the defense industry, but also in the national economy, and in particular in the energy field:⁶li and⁷li is an important material for future nuclear fusion reactor fuels and nuclear fission reactions, respectively: it is also increasingly demanded as a battery material. Therefore, lithium is called "energy metal in the 21 st century". The demand for lithium is continuously increasing at home and abroad, and thus research, development and utilization of lithium resources are urgently needed.

Lithium-containing brines are an important source of lithium. China has abundant lithium-containing brine lithium resources, and the storage quantity of the lithium-containing brine lithium resources is in the forefront of the world. However, since brine contains many kinds of metal ions, the comprehensive utilization thereof and the technology of separating and extracting lithium from brine are important problems to be studied, and particularly, the technology of separating and extracting lithium from brine containing high-concentration magnesium and low-concentration lithium, namely, high magnesium-lithium ratio, is a recognized worldwide technical problem.

The solvent extraction technology is an effective technology for separating and extracting various metals from a solution, has the advantages of high separation efficiency, simple process and equipment, continuous operation, easy realization of automatic control and the like, and is considered to be one of the most promising methods for extracting and separating lithium from brine with a high magnesium-lithium ratio. Since the mid-sixties of the last century, several extraction systems and processes have been proposed at home and abroad, specifically as follows:

(1) in 1967, Nelli J.R. invented an extraction system and its process [1.Nelli J.R ].etal.Fr.1,535,818(1967)；USP3,537,813(1970).]: adding FeC1 into brine₃As a co-extraction agent, 80% diisobutyl ketone-20% tributyl phosphate is used as an organic phase, and Li and Fe are used as LiFeC1₄Form co-extraction is carried out into an organic phase and a large amount of MgC1 is mixed with an aqueous phase₂And other metals. The system has high selectivity for Li extraction, but the LiCl and FeC1 are generated by water back extraction₃The mixed solution needs to be extracted and separated again by a di (2-ethylhexyl) phosphoric acid-tributyl phosphate system to separate Li and Fe, so the process is long and the operation is complicated, and the application of the mixed solution in industrial production is not seen so far.

(2) In 1979, the research institute of Qinghai salt lake, Chinese academy of sciences proposed a system and a process for extracting lithium from kerosene solution of tributyl phosphate as a single extractant, thereby simplifying the extraction system, and semi-industrial experiments were conducted in 1984 for extracting lithium from lithium-containing brine of Dachai Dan, and in 1987, a Chinese patent of invention [3. Huangshi Qiang et al, Chinese patent of invention, CN137103431] was applied and granted. However, the extraction agent adopted in the system is tributyl phosphate, which has strong corrosivity to extraction equipment, and tributyl phosphate is not only dissolved and lost in water in long-term operation, but also easily degraded in an acidic medium, and particularly the severe swelling effect of tributyl phosphate on materials for manufacturing the extraction equipment limits the industrial large-scale application of tributyl phosphate.

(3) CN103055539A discloses a method for extracting lithium salt from lithium-containing brine, which adopts a co-extraction agent, an extraction agent and a diluent to extract lithium, solves the problem that the former two extraction systems and processes are highly corrosive to equipment and difficult to industrialize, and obtains better extraction and back-extraction performances. The method is still pure in various problems in the industrial process, such as low single-stage extraction rate, influence on yield and yield, and extraction stages are increased for obtaining high yield; the separation coefficient of lithium from magnesium, sodium and potassium is not large enough, the directly obtained product cannot meet the requirement of high purity, and the washing grade number or other post-treatment modes must be increased. Therefore, how to further improve the extraction and back-extraction performance of lithium salt from lithium-containing brine, save cost, and be more suitable for industrial production becomes a technical problem to be solved in the field.

Disclosure of Invention

The invention aims to solve the technical problems of long process, complex operation, strong corrosion to equipment, insufficient extraction rate and back-extraction performance and the like in the conventional extraction system and process for extracting lithium salt from lithium-containing brine, and provides an extraction composition, an extraction system and application thereof. According to the invention, the mixture of the amide compound with a specific structure and the neutral phosphorus-oxygen compound is selected as the extracting agent, so that the extraction rate of Li in the lithium-containing brine is up to 91.69%; the distribution coefficient of lithium and magnesium is up to 823; when the HCl is used for back extraction of lithium, the back extraction rate is 84.58-90.40%, the extraction and back extraction performance of lithium salt extracted from lithium-containing brine is greatly improved, the cost is saved, and the method is more suitable for industrial production.

The present invention solves the above technical problems by the following technical solutions.

The invention provides an extraction composition, which comprises an extracting agent and a neutral phosphorus-oxygen compound shown as a formula A; the extractant comprises N, N-di (2-ethylhexyl) propionamide but does not comprise N, N-di (2-ethylhexyl) acetamide;

wherein, in the neutral phosphorus oxygen compound shown as the formula A, R¹And R²Independently is C₁-C₁₂Straight-chain or branched alkyl, C₁-C₁₂Linear or branched alkoxy, phenyl, substituted phenyl, phenoxy, substituted phenoxy, thienyl, pyridyl or naphthyl; said substituent of said substituted phenyl or said substituted phenoxy is one or more of the following groups: halogen, C₁-C₆Alkyl, hydroxy, C₁-C₆Alkoxy, trifluoromethyl, trifluoromethoxy, phenoxy, piperidinyl, morpholinyl, pyrrolyl, tetrahydropyrrolyl, nitro or amino; when the substituent is plural, the substituents may be the same or different.

In the neutral phosphorus-oxygen compound shown as the formula A, R¹And R²Preferably independently C₁-C₈Straight-chain or branched alkyl, or C₁-C₈Linear or branched alkoxy; wherein, said C₁-C₈The linear or branched alkyl group is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 1-methyl-heptyl or 2-ethyl-hexyl. Said C₁-C₈The linear or branched alkoxy group is preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, 1-methyl-heptoxy or 2-ethyl-hexyloxy.

The neutral phosphorus-oxygen compound shown in the formula A is preferably one or more of the following compounds:

in the extraction composition, the volume ratio of the extraction agent to the neutral phosphorus oxygen compound shown in the formula A can be the conventional proportion of the extraction system in the field. The volume ratio of the extracting agent to the neutral phosphorus-oxygen compound shown in the formula A is preferably 9:1-1:9, more preferably 5:2-2:5 (such as 2:1), and further preferably 5:4-2:3 (such as 1: 1).

The extractant may also preferably further comprise other amide compounds; the other amide-based compounds are preferably selected from one or more of the amide-based compounds shown as follows:

when the extractant further comprises other amide-based compounds as described above, the amount of the other amide-based compounds used may not be particularly limited as long as the extraction and stripping performance of the extractant is not affected. The content of the N, N-di (2-ethylhexyl) propionamide in the extracting agent is preferably 0.01 to 99.9 percent, and more preferably 10 to 60 percent. The volume ratio of the N, N-di (2-ethylhexyl) propionamide to other amide compounds is preferably 4:1-1:4, and more preferably 1: 1.

The extraction composition may further comprise a diluent. The diluent can be any diluent conventional in the art, preferably an aliphatic hydrocarbon (for example n-dodecane) or an aromatic hydrocarbon with a boiling point greater than or equal to 100 ℃ at atmospheric pressure, and can also be kerosene. The amount of the diluent to be used is not particularly limited as long as the extraction performance of the extractant is not affected. The volume content of the diluent is preferably 10% to 80%, more preferably 10% to 50%, most preferably 20% to 40%, and the percentage refers to the volume percentage of the diluent to the total volume of the extraction composition.

When the extraction composition contains other components in addition to the extractant and the neutral phosphorus oxy-compound, the extractant and the neutral phosphorus oxide are preferably present in the extraction composition in an amount of 20% to 90%, more preferably 50% to 80%, and most preferably 60% to 70% by volume.

The extraction composition may further comprise a co-extractant. The co-extractant can be dissolved in the water phase firstly during extraction, and can also be stabilized in the organic phase firstly. The co-extractant generally refers to ferric salt capable of obviously improving the extraction rate of lithium, and can be one or more of ferric trichloride, ferric sulfate, ferric nitrate and ferric phosphate, and preferably is ferric trichloride. The dosage of the co-extraction agent can be the conventional dosage in the fields of lithium-containing brine extraction and lithium back extraction, and is generally calculated according to the content of lithium in a substance to be extracted, and the substance to be extracted is preferably lithium-containing brine; the amount of the co-extractant used is generally such that the molar ratio of ferric ions to lithium ions is from 1:1 to 2:1, more preferably from 1:1 to 1.75:1, and still more preferably from 1.3:1 to 1.5: 1.

The extractant preferably consists of one or more of N, N-di (2-ethylhexyl) -2-methoxyacetamide, N-dihexylpropionamide and N, N-dihexylp-methylbenzamide and N, N-di (2-ethylhexyl) propionamide.

The extraction composition preferably consists of the extraction agent and the neutral phosphorus-oxygen compound shown as the formula A.

The extraction composition more preferably consists of the extractant, the neutral phosphorus oxygen compound shown in the formula A and the diluent.

The extraction composition further preferably comprises the extractant, the neutral phosphorus-oxygen compound shown in the formula A, the diluent and the co-extractant.

The invention also provides an extraction system comprising an extraction composition as described above and a lithium-containing brine.

The volume ratio of the organic phase of the extraction composition to the lithium-containing brine in the extraction system can be any volume ratio conventional in the art, preferably 1:5 or more, for example 1:2 to 10:1 (e.g., 1:1), more preferably 2:1 to 6: 1. In the present invention, the organic phase of the extraction composition generally does not contain a co-extractant.

The invention also provides the use of an extraction composition as hereinbefore described for extracting or stripping lithium from lithium-containing brines.

The application of extracting lithium from lithium-containing brine preferably comprises the following steps: mixing the extraction composition with lithium-containing brine, oscillating for balancing, and standing for layering.

The use of stripping lithium from lithium-containing brine preferably comprises the steps of:

(1) mixing the extraction composition with lithium-containing brine, oscillating for balancing, standing for layering to obtain an organic phase loaded with lithium ions;

(2) and mixing the lithium ion loaded organic phase with an acid aqueous solution, oscillating for balancing, and standing for layering.

In the application of extracting lithium from lithium-containing brine or the application of back-extracting lithium from lithium-containing brine, mass transfer is carried out by oscillation. In addition, the mass transfer and phase separation process can be completed by means of extraction equipment such as a centrifugal extractor, a mixing and clarifying tank, an extraction tower and the like. The centrifugal extractor, the mixer-settler and the extraction tower can be conventional extraction equipment in the field, and the using conditions and the method can refer to the conventional using conditions and the method for extracting lithium from the lithium-containing aqueous solution.

In the application of extracting lithium from lithium-containing brine or the application step (1) of extracting lithium from lithium-containing brine, the volume ratio of the organic phase of the extraction composition to the lithium-containing brine can be a volume ratio conventional in the art, and is preferably 1:5 or more, for example, 1:2 to 10:1 (e.g., 1:1), and more preferably 2:1 to 6: 1. In the present invention, the organic phase of the extraction composition generally refers to the extraction composition when no co-extractant is included.

In the step (1) of extracting from lithium-containing brine or extracting lithium from lithium-containing brine, the temperature of the extraction composition and the lithium-containing brine is preferably 10 ℃ to 50 ℃ (for example, 25 ℃ to 40 ℃) during the oscillating equilibrium, that is, the oscillating equilibrium is performed at 10 ℃ to 50 ℃. The period of equilibration of the oscillation may be conventional in the art, preferably 5 to 30 minutes.

In the application step (2) of stripping lithium from lithium-containing brine, the molar concentration of the aqueous acid solution is preferably 0.5mol/L-12.0mol/L, more preferably 4mol/L-10mol/L, and even more preferably 6mol/L-8mol/L, wherein the molar concentration refers to the ratio of the amount of acid substances to the total volume of the aqueous acid solution. The acid in the aqueous acid solution may be an acid conventional in the art, and is preferably an inorganic acid. The inorganic acid is preferably one or more of hydrochloric acid, sulfuric acid and nitric acid, more preferably hydrochloric acid. The volume ratio of the lithium ion-supporting organic phase to the aqueous acid solution may be a volume ratio conventionally used in the art, and is preferably 1:1 to 50:1, more preferably 5:1 to 40:1, and still more preferably 10:1 to 30: 1.

In the invention, the lithium-containing brine can be conventional lithium-containing brine in the field, and the lithium-containing brine with high magnesium-lithium ratio is preferred in the invention, and the magnesium-lithium ratio in the high magnesium-lithium ratio is preferably 2-30 (for example 16). The lithium-containing brine preferably comprises: 0.02mol/L to 2.0mol/L (e.g., 0.144mol/L, 0.29mol/L) of Li⁺2.0mol/L to 5.0mol/L (e.g., 4mol/L, 4.32mol/L, 4.64mol/L) of Mg²⁺0mol/L to 0.5mol/L (0.05mol/L, 0.1mol/L, 0.4mol/L) of Na⁺K of 0mol/L to 0.5mol/L (e.g., 0.02mol/L, 0.4mol/L)⁺And Cl of ≧ 6mol/L (e.g., 9.2mol/L, 9.8mol/L, 10.7mol/L)^-0mol/L to 0.90mol/L (0.01mol/L, 0.1mol/L) of B₂O₃And 0.001mol/L to 0.5mol/L (e.g., 0.04mol/L, 0.05mol/L, 0.3mol/L) of H⁺(acidity of brine), and the balance of water.

In the present invention, the normal pressure refers to 1 atmosphere, i.e., 101.325 kPa.

In the present invention, the volume ratio or volume fraction refers to the volume ratio or volume fraction of each substance at room temperature.

In the present invention, room temperature means 10 ℃ to 30 ℃.

In the present invention, the shaking operation may be performed by stirring or the like, and the purpose thereof is to uniformly mix the organic phase and the aqueous phase.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows: according to the invention, the mixture of the amide compound with a specific structure and the neutral phosphorus-oxygen compound is selected as the extracting agent, so that the extraction rate of Li in the lithium-containing brine is up to 91.69%; the distribution coefficient of lithium and magnesium is up to 823; when the HCl is used for back extraction of lithium, the back extraction rate is 84.58-90.40%, the extraction and back extraction performance of lithium salt extracted from lithium-containing brine is greatly improved, the cost is saved, and the method is more suitable for industrial production.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions. Unless otherwise specified, the parts referred to in the following examples refer to parts by volume.

In the following examples, the basic concepts of phase comparison, distribution ratio, extraction separation factor, and the like are as follows:

(1) compare

For a batch extraction process, the volume of organic phase extracted, V (m)³) Mixing with feed liquid waterPhase L (m)³) The ratio of the two is called the phase ratio; for a continuous extraction process, the extract phase volume flow rate V (m)³S) and volume flow L (m) of the feed liquid phase³The ratio/s), also referred to as phase ratio or two-phase flow ratio, is herein collectively referred to as O/A for two-phase volume or flow. Compared with the formula shown by R:

in the formula: v_oVolume of the extract phase, V_aIs the volume of the feed liquid phase

(2) Extraction rate

The extraction rate is the percentage of the extracted material transferred from the feed liquid phase to the extraction phase in the extraction process to the total amount of the extracted material in the feed liquid phase, and represents the degree of extraction separation. The formula for calculating the extraction rate E (%) is:

in the formula: n is_aN is the amount of extracted material in the feed solution_oThe amount of extracted material in the raffinate.

(3) Distribution ratio

The distribution ratio is also called the distribution coefficient. The partitioning behavior of extracted substance a in the two phases can be understood as the overall effect of a partitioning of a in the two phases in the various forms a1, a 2. In general, the experimentally determined values represent the total concentration of the various forms of extracted material present in each phase. The system partition coefficient is defined as the ratio of the total concentration of extracted substances in the extraction organic phase (O) to the total concentration in the feed liquid phase (A) under certain conditions when the system reaches equilibrium, and is represented by D:

the partition ratio represents the actual partition ratio of the extracted substances in the two phases after the extraction system reaches equilibrium and is generally determined experimentally. The larger the distribution ratio of the extracted substance is, the easier the substance is to be extracted, and the distribution ratio is related to the extraction conditions, such as the concentration and acidity of the extracted substance in the aqueous phase, other coexisting substances, the type and concentration of the extractant in the organic substance, the type of the diluent, the temperature during extraction, and the like.

(4) Separation factor

When extraction separation is performed under certain conditions, the ratio of the extraction distribution ratio of two substances to be separated between two phases is called extraction separation factor, also called extraction separation coefficient, and is usually expressed by beta. If A, B represents two substances to be separated, respectively, then there are:

in the formula: d_AIs the distribution ratio of A substance, D_BThe distribution ratio of the B substance is shown.

The extraction separation coefficient quantitatively represents the difficulty of a certain extraction system in separating two substances in a feed liquid phase. When the beta value is 1, the two substances cannot be separated, and the larger or smaller the beta value is, the better the separation effect is, namely, the higher the separation selectivity of the extractant is.

Examples 1 to 9

Organic phase: extracting agent, neutral phosphorus-oxygen compound and diluent

Water phase: lithium-containing brine

The ratio (O: A) represents the volume ratio of the organic phase to the aqueous phase.

The specific operation is as follows:

adding a certain amount of FeCl₃Adding the (co-extraction agent) into lithium-containing brine, shaking to dissolve the lithium-containing brine, adding an organic phase, shaking for balancing (the shaking time is 5-30 minutes), and standing for layering (obtaining a balanced organic phase containing lithium ions and an aqueous phase). Separately measuring Li in equilibrium aqueous phase and organic phase⁺、Na⁺、K⁺And Mg²⁺From the concentration of (b), the extraction rate of Li, was calculated⁺、Mg²⁺、Na⁺And K⁺Partition ratio of (1), separation system of Li/Mg, Li/Na, and Li/KAnd (4) counting.

Example 10

Organic phase: extracting agent, neutral phosphorus oxide and diluent;

water phase: a lithium-containing brine;

comparison (O: A): refers to the volume ratio of the organic phase to the aqueous phase;

the specific operation is as follows:

adding a certain amount of FeCl₃Adding the (co-extraction agent) into an organic phase, then adding an aqueous phase, oscillating for balancing (oscillation time is 30 minutes), standing for layering to obtain a balanced aqueous phase and an organic phase containing lithium ions. Separately measuring Li in equilibrium aqueous phase and organic phase⁺、Na⁺、K⁺And Mg²⁺From the concentration of (b), the extraction rate of Li, was calculated⁺、Mg²⁺、Na⁺And K⁺Partition ratio of (A), separation coefficient of Li/Mg, Li/Na, and Li/K.

The experimental procedures of comparative examples 1 to 4 were the same as those of example 1.

The detailed information of examples 1 to 10 and comparative examples 1 to 4 is shown in tables 1, 2 and 3.

TABLE 1 ingredients and specific contents (mol/L) of Li-containing brine in examples 1-10 and comparative examples 1-4

TABLE 2 extraction conditions and operating parameters in examples 1-10 and comparative examples 1-4

TABLE 3 extraction results of examples 1-10 and comparative examples 1-4

Note: except that the phase is three after extraction in the comparative example 2, the phase separation effect of other examples and comparative examples is good, the water phase is colorless, and the interface of the two phases is clear.

Example 11

An efficient extraction system is required to have not only excellent extraction performance but also good back-extraction performance.

Organic phase: the lithium-containing organic phases obtained in examples 1, 5, 10 and comparative examples 5, 6;

water phase: 6mol/L hydrochloric acid aqueous solution;

(ii) compared to (O/a) 30: 1;

30 parts of each of the lithium-containing organic phases equilibrated by extraction in examples 1, 5 and 10 was mixed with 1 part of 6mol/L aqueous hydrochloric acid, and the mixture was shaken at 25 ℃ for 10 minutes to carry out back extraction and then allowed to stand for delamination. The lithium ion concentration in the two phases of the stripping equilibrium is measured. Specific parameters and results are shown in table 4 below.

Wherein the extraction composition of comparative example 5 was 20% N, N-bis (2-ethylhexyl) acetamide + 30% TBP + kerosene and the extraction composition of comparative example 6 was 80% TBP + kerosene, each loaded with an organic phase lithium ion concentration as shown in table 4 below. (see patent CN103055539B)

TABLE 4 stripping results for examples 1, 5, 10 and comparative examples 5, 6

Preparation example 1: preparation of the extractant

General procedure of the experiment: in a 2L three-necked flask equipped with a thermometer, a dropping funnel having a constant pressure, and mechanical stirring, 1mol of dialkylamine, 400mL of methylene chloride, and 153mL (1.1mol) of triethylamine were charged, respectively, stirring was turned on, and the system was cooled to 0 ℃ while placing 1.05mol of acid chloride and about 200mL of a methylene chloride solution in the dropping funnel and starting the dropwise addition while keeping the temperature of the system at 15 ℃ or less, and the dropwise addition was completed in about 30 minutes. The ice bath was removed and the reaction was allowed to proceed overnight at room temperature. Adding water with the same volume to dissolve the generated solid, separating by a separating funnel, washing the organic phase by dilute hydrochloric acid and saturated saline solution, drying by anhydrous sodium sulfate, removing the solvent, and distilling under reduced pressure.

Wherein Yield is Yield, IR (thin film) is infrared (thin film method), EA is elementary analysis, calcd.

3.13-3.34(m,2H),3.14(d,2H),2.09(s,1H),1.59-1.68(m,2H),1.23-1.39(m,16H),0.85-0.91(m,12H)；¹³CNMR(100MHz,CDCl₃)170.903,52.095,48.311,38.284,36.898,30.561,30.473,28.752,28.716,23.859,23.764,23.035,22.991,21.970,14.022,13.985,10.806,10.638；IR(thin film):2961,2929,2873,2857,1651,1463,1379,1234,1185,1037cm^-1；MS(ESI):284.7(M⁺+1),306.3(M⁺+Na)；EA:calcd.for C₁₈H₃₇NO:C,76.26；H,13.14；N,4.94,Found:C,76.29；H,13.19；N,4.91.

CDCl₃)3.21-3.32(m,2H),3.13(d,2H),2.35(dd,2H),1.56-1.57(m,1H),1.65-1.68(m,1H)1.23-1.35(m,16H),1.14(t,3H),0.84-0.89(m,12H)；¹³CNMR(100MHz,CDCl₃)174.450,51.384,48.827,38.423,36.959,30.576,30.498,28.771,28.701,26.555,23.898,23.774,23.053,23.007,14.036,14.013,10.844,10.666,9.868；IR(thin film):2959,2929,2873,1651,1464,1425,1378,1220，1205，1071cm^-1；MS(ESI):298.8(M⁺+1)；EA:calcd.for C₁₉H₃₉NO:C,76.70；H,13.21；N,4.71,Found:C,76.41；H,13.47；N,4.86.

83％；130～132℃/7×10^-3mba；¹H NMR(400 MHz,CDCl₃)4.08(s,2H),3.40(s,2H),3.21-3.33(m,2H),3.10(d,2H),1.55-1.56(m,1H),1.64-1.67(m,1H),1.21-1.26(m,16H),0.83-0.88(m,12H)；¹³CNMR(100MHz,CDCl₃)169.516,71.425,59.014,49.951,47.898,37.881,36.610,30.498,28.771,28.670,23.782,23.030,22.976,14.028,13.990,10.860,10.573；IR(thin film):2958,2929,2873,2823,1651,1459,1379,1263,1196,1116cm^-1；MS(ESI):314.3(M⁺+1),336.3(M⁺+Na)；EA:calcd.for C₁₉H₃₉NO₂:C,72.79；H,12.54；N,4.47,Found:C,72.30；H,12.85.；N,4.56.

1.10(s,3H),1.11(s,3H),0.84-0.90(m,12H)；¹³CNMR(100MHz,CDCl₃)177.789,51.422,49.091,38.950,37.083,30.529,30.459,30.250,28.771,28.716,23.851,23.720,23.053,23.007,19.575,14.036,14.005,10.868,10.651；IR(thin film):2960,2929,2873,1647,1467,1430,1380,1220,1126,1085cm^-1；MS(ESI):312.7(M⁺+1),334.3(M⁺+Na)；EA:calcd.for C₂₀H₄₁NO:C,77.10；H,13.27；N,4.50,Found:C,76.98；H,13.59；N,4.76.

3.28-3.30(m,4H),1.60-1.63(m,2H),1.18-1.32(m,25H),0.85-0.89(m,12H)；¹³CNMR(100MHz,CDCl₃)178.355,39.492,30.545,29.220,29.166,29.096,28.988,28.895,23.875,23.053,14.036,11.077,11.030,10.984；IR(thin film):2959,2929,2873,1633,1464,1412,1379,1364,1187,1120cm^-1；MS(ESI):326.7(M⁺+1)；EA:calcd.for C₂₁H₄₃NO:C,77.47；H,13.31；N,4.30,Found:C,77.54；H,13.38；N,4.49.

2H),3.14(t,2H),2.07(s,3H),1.50-1.53(m,4H),1.27-1.28(m,12H),0.85-0.88(m,6H)；¹³CNMR(100MHz,CDCl₃)170.174,48.866,45.829,31.606,31.490,28.856,27.678,26.679,26.516,22.550,21.404,13.998,13.951；IR(thin film):2957,2929,2873,2858,1648,1458,1422,1378,1260,1108cm^-1；MS(ESI):228.6(M⁺+1),250.3(M⁺+Na)；EA:calcd.for C₁₄H₂₉NO:C,73.95；H,12.86；N,6.16,Found:C,73.00；H,12.87；N,6.15.

3.13-3.35(m,2H),2.33(dd,2H),1.14-1.16(m,4H),1.20-1.35(m,12H),1.13(t,3H),0.81-0.91(m,6H)；¹³CNMR(100MHz,CDCl₃)173.373,47.913,45.992,31.544,31.464,29.003,27.702,26.609,22.558,13.966,9.682；IR(thin film):2957,2929,2858,1651,1465,1425,1375,1193,1074cm^-1；MS(ESI):242.7(M⁺+1),264.3(M⁺+Na)；EA:calcd.for C₁₅H₃₁NO:C,74.63；H,12.94；N,5.80,Found:C,74.05；H,13.48；N,5.98.

3.19-3.30(m,4H),2.69-2.76(m,1H),1.46-1.55(m,4H),1.21-1.35(m,12H),1.11(s,3H),1.09(s,3H),0.83-0.91(m,6H)；¹³CNMR(100MHz,CDCl₃)176.821,31.544,30.119,26.571,22.558,19.699,13.966；IR(thin film):2959,2929,2858,1644,1470,1425,1378,1135,1085cm^-1；MS(ESI):256.7(M⁺+1),278.3(M⁺+Na)；EA:calcd.for C₁₆H₃₃NO:C,75.23；H,13.02；N,5.48,Found:C,74.88；H,13.40；N,5.87.

(m,5H),3.35-3.54(m,2H),3.07-3.30(m,2H),1.48-1.63(m,4H),1.00-1.48(m,12H),0.61-0.74(m,6H)；¹³C NMR(100 MHz,CDCl₃)171.638,137.296,134.523,130.549,128.992,128.860,128.829,128.310,128.155,126.428,126.304,126.265,48.998,48.874,44.729,44.636,31.598,31.498,31.288,31.157,28.554,28.430,27.585,27.469,27.376,26.780,26.679,26.524,26.253,26.206,22.496,13.959；IR(thin film):2956,2929,2857,1636,1466,1423,1379,1300,1267,1107,1074cm^-1；MS(ESI):290.6(M⁺+1),312.3(M⁺+Na)；EA:calcd.for C₁₉H₃₁NO:C,78.84；H,10.80；N,4.84,Found:C,78.35；H,10.62；N,4.96.

CDCl₃)7.16-7.18(m,2H),7.19-7.26(m,2H),3.30-3.48(m,2H),3.19-3.29(m,2H),2.36(s,3H),1.42-1.65(m,4H),1.00-1.39(m,12H),0.75-0.91(m,6H)；¹³CNMR(100MHz,CDCl₃)171.832,138.970,134.322,130.611,129.550,128.891,126.505,49.021,48.959,44.900,44.791,44.737,44.698,31.451,31.226,28.585,28.476,28.438,28.414,28.391,28.329,27.616,27.562,27.500,27.477,27.407,26.811,26.656,26.540,26.540,26.501,26.346,26.299,26.121,22.511,21.318,13.959；IR(thin film):2956,2928,2858,1636,1466,1422,1378,1180,1105,1020cm^-1；MS(ESI):304.7(M⁺+1),326.3(M⁺+Na)；EA:calcd.for C₂₀H₃₃NO:C,79.15；H,10.96；N,4.62,Found:C,78.95；H,11.04；N,4.61.

(m,4H),2.26(t,2H),1.60-1.71(m,2H),1.42-1.55(m,4H),1.20-1.35(m,12H),0.88-1.02(m,9H)；¹³CNMR(100MHz,CDCl₃)172.599,47.991,47.952,45.907,34.953,31.529,29.081,27.717,26.671,26.547,22.558,18.924,13.966；IR(thin film):2958,2929,2858,1647,1465,1423,1378,1297,1250,1191,1145,1093cm^-1；MS(ESI):304.7(M⁺+1),326.3(M⁺+Na)；EA:calcd.for C₁₆H₃₃NO:C,75.23；H,13.02；N,5.48,Found:C,74.68；H,13.31；N,5.60.

A solution of acetoxyacetyl chloride (25 g, 0.183mol) in methylene chloride (30 mL) was added dropwise to a reaction flask containing diisooctylamine (52 mL, 0.183mol), triethylamine (31 mL, 0.222mol) and methylene chloride (150 mL) at 0 ℃ and then the mixture was reacted at room temperature overnight. Adding water with the same volume to dissolve the generated solid and separating out an organic phase, washing with dilute hydrochloric acid and water, drying with anhydrous sodium sulfate, and removing the solvent to obtain a crude product. The crude product obtained is reacted with 11g (0.262mol) of lithium hydroxide monohydrate dissolved in 180mL of methanol and 30mL of water with stirring at room temperature for 1 hour. Most of methanol is removed by rotation, and then dichloromethane is used for extraction, diluted hydrochloric acid is used for washing, anhydrous sodium sulfate is used for drying, then the solvent is removed, and reduced pressure distillation is carried out.

4.14(s,2H),3.27-3.38(m,3H),2.94(d,2H),1.57-1.60(m,1H),1.66-1.69(m,1H),1.22-1.27(m,16H),0.85-0.90(m,12H)；¹³CNMR(100MHz,CDCl₃)172.033,59.905,49.044,48.587,37.610,36.641,30.475,28.763,28.631,23.797,23.774,23.015,22.945,14.021,13.990,10.821,10.573；IR(thin film):3411，2959,2929,2873,2859,1648,1464,1404,1380,1278,1087cm^-1；MS(ESI):300.8(M⁺+1),322.4(M⁺+Na)；EA:calcd.for C₁₈H₃₇NO₂:C,72.19；H,12.45；N,4.68,Found:C,72.10；H,12.67；N,4.90.

40mL (0.423mol) of ethoxyacetic acid was placed in a 250mL flask, 38mL (0.443mol) of oxalyl chloride and several drops of pyridine were added as a catalyst, the mixture was refluxed at 80 ℃ for 2 hours, and then excess oxalyl chloride was removed to prepare a 50% dichloromethane solution, which was then placed in a dropping funnel, added dropwise to a reaction flask containing 100mL (0.333mol) of diisooctylamine, 51mL (0.368mol) of triethylamine and 250mL of dichloromethane at 0 ℃ and reacted overnight at room temperature after the addition. Adding water with the same volume to dissolve the generated solid and separating out an organic phase, washing with dilute hydrochloric acid and water, drying with anhydrous sodium sulfate, removing the solvent to obtain a crude product, and distilling under reduced pressure.

CDCl₃)4.12(s,2H),3.55(dd,2H),3.20-3.31(m,2H),3.12(d,2H),1.65-1.67(m,1H),1.55-1.57(m,1H),1.20-1.26(m,19H),0.75-0.91(m,12H)；¹³CNMR(100MHz,CDCl₃)169.864,69.775，66.777,50.594，50.570，50.067，47.983,37.904,36.603,35.456，35.441，30.498,30.359,28.794,28.685,28.224，28.221，23.782,23.658,23.642,23.022，22.976,22.821,15.035，14.021,13.990,10.868,10.597，10.132，10.101；IR(thin film):2959,2929,2873,1647,1459,1379,1276,1229,1112,1030cm^-1；MS(ESI):304.7(M⁺+1),326.3(M⁺+Na)；EA:calcd.for C₂₀H₄₁NO₂:C,73.34；H,12.62；N,4.28,Found:C,72.53；H,12.92；N,4.50.

Claims

1. An extraction composition is characterized by comprising an extracting agent and a neutral phosphorus-oxygen compound shown as a formula A; the extraction composition further comprises a diluent, wherein the volume content of the diluent is 30-80%, and the percentage refers to the volume percentage of the diluent in the total volume of the extraction composition; the extractant comprises N, N-di (2-ethylhexyl) propionamide but does not comprise N, N-di (2-ethylhexyl) acetamide;

2. The extraction composition of claim 1, wherein R is the neutral phosphorus oxygen compound of formula A¹And R²Independently is C₁-C₈Straight-chain or branched alkyl, or C₁-C₈Linear or branched alkoxy.

3. The extraction composition of claim 2, wherein R is¹And R²In (b), the C₁-C₈Straight-chain or branched alkyl is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 1-methyl-heptyl or 2-ethyl-hexyl;

and/or, R¹And R²In (b), the C₁-C₈Straight-chain or branched alkoxy is methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, 1-methyl-heptyloxy or 2-ethyl-hexyloxy.

4. The extraction composition according to any one of claims 1 to 3, wherein the neutral phosphorus oxygen compound of formula A is one or more of the following compounds:

5. the extraction composition of claim 1, wherein the volume ratio of the extractant to the neutral phosphorus oxygen compound of formula a is from 9:1 to 1: 9.

6. The extraction composition of claim 5, wherein the volume ratio of the extractant to the neutral phosphorus oxygen compound of formula A is from 5:2 to 2: 5.

7. The extraction composition of claim 6, wherein the volume ratio of the extractant to the neutral phosphorus oxygen compound of formula A is from 5:4 to 2: 3.

8. The extraction composition of claim 1, wherein the extractant further comprises other amide compounds.

9. The extraction composition according to claim 8, wherein the other amide compound is selected from one or more of the following amide compounds:

10. an extraction composition according to claim 8 or 9, wherein when the extraction reagent further comprises other amide compounds, the N, N-bis (2-ethylhexyl) propionamide is present in the extraction reagent in an amount of from 0.01% to 99.9%;

and/or the volume ratio of the N, N-di (2-ethylhexyl) propionamide to other amide compounds is 4:1-1: 4.

11. The extraction composition according to claim 10, wherein when the extraction agent further comprises other amide compounds, the content of N, N-bis (2-ethylhexyl) propionamide in the extraction agent is 10% to 60%;

and/or the volume ratio of the N, N-di (2-ethylhexyl) propionamide to other amide compounds is 1: 1.

12. The extraction composition of claim 1, wherein the diluent is one or more of an aliphatic hydrocarbon having a boiling point at atmospheric pressure of 100 ℃ or higher, an aromatic hydrocarbon having a boiling point at atmospheric pressure of 100 ℃ or higher, and kerosene.

13. The extraction composition of claim 1 wherein said extractant and said neutral phosphorus oxide are present in said extraction composition in an amount of from 20% to 90% by volume.

14. The extraction composition of claim 13 wherein said extractant and said neutral phosphorus oxide are present in said extraction composition in an amount of from 50% to 80% by volume.

15. The extraction composition of claim 14 wherein said extractant and said neutral phosphorus oxide are present in said extraction composition in an amount of from 60% to 70% by volume.

16. The extraction composition of any one of claims 1, 12-15, further comprising a co-extractant.

17. The extraction composition of claim 16, wherein the co-extractant is one or more of ferric chloride, ferric sulfate, ferric nitrate, and ferric phosphate;

and/or the dosage of the co-extraction agent is calculated by the content of lithium in the material to be extracted, and the material to be extracted is lithium-containing brine;

and/or the dosage of the co-extraction agent is that the molar ratio of ferric ions to lithium ions is 1:1-2: 1.

18. The extraction composition of claim 17, wherein the co-extractant is used in an amount such that the molar ratio of ferric ion to lithium ion is from 1:1 to 1.75: 1.

19. The extraction composition of claim 18, wherein the co-extractant is used in an amount such that the molar ratio of ferric ion to lithium ion is from 1.3:1 to 1.5: 1.

20. An extraction system comprising the extraction composition of any one of claims 1-19 and a lithium-containing brine.

21. Use of an extraction composition according to any one of claims 1 to 19 for extracting or stripping lithium from lithium-containing brine.

22. The use of claim 21, wherein:

the application of extracting lithium from lithium-containing brine comprises the following steps: mixing the extraction composition with lithium-containing brine, oscillating for balancing, and standing for layering;

the application of the lithium stripping from the lithium-containing brine comprises the following steps: (1) mixing the extraction composition with lithium-containing brine, oscillating for balancing, standing for layering to obtain an organic phase loaded with lithium ions; (2) and mixing the lithium ion loaded organic phase with an acid aqueous solution, oscillating for balancing, and standing for layering.

23. The use of claim 22, wherein in said use of extracting lithium from a lithium-containing brine or said use of back-extracting lithium from a lithium-containing brine step (1), the volume ratio of said organic phase of the extraction composition to said lithium-containing brine is 1:5 or more;

and/or, the organic phase of the extraction composition does not comprise a co-extractant;

and/or, in said application of extraction from lithium-containing brine or application step (1) of back-extracting lithium from lithium-containing brine, the temperature of said extraction composition and said lithium-containing brine at said oscillating equilibrium is between 10 ℃ and 50 ℃;

and/or, in the application of extraction from lithium-containing brine or the application step (1) of stripping lithium from lithium-containing brine, the time of the oscillation equilibrium is 5 to 30 minutes;

and/or in the application step (2) for stripping lithium from lithium-containing brine, the molar concentration of the aqueous solution of the acid is 0.5-12.0 mol/L, and the molar concentration refers to the ratio of the amount of the substance of the acid to the total volume of the aqueous solution of the acid;

and/or, in the application step (2) for stripping lithium from lithium-containing brine, the acid in the acid aqueous solution is an inorganic acid;

and/or in the application step (2) for back-extracting lithium from lithium-containing brine, the volume ratio of the lithium ion-loaded organic phase to the acid aqueous solution is 1:1-50: 1;

and/or in the application of extracting lithium from lithium-containing brine or the application of back extracting lithium from lithium-containing brine, the ratio of magnesium to lithium in the lithium-containing brine is 2-30;

and/or, the lithium-containing brine comprises the following components in percentage by weight: 0.02mol/L-2.0mol/L Li⁺2.0mol/L to 5.0mol/L of Mg²⁺0mol/L to 0.5mol/L of Na⁺0mol/L to 0.5mol/L of K⁺Cl of not less than 6mol/L^-0mol/L to 0.90mol/L of B₂O₃And 0.001mol/L to 0.5mol/L of H⁺And the balance of water.

24. The use of claim 23, wherein in said use of extracting lithium from a lithium-containing brine or said use of extracting lithium from a lithium-containing brine in step (1), the volume ratio of said organic phase of the extraction composition to said lithium-containing brine is from 1:2 to 10: 1;

and/or, in said application of extraction from lithium-containing brine or application step (1) of back-extracting lithium from lithium-containing brine, the temperature of said extraction composition and said lithium-containing brine at said oscillating equilibrium is between 25 ℃ and 40 ℃;

and/or in the application step (2) for stripping lithium from lithium-containing brine, the molar concentration of the aqueous solution of the acid is 4-10 mol/L, and the molar concentration refers to the ratio of the amount of substances of the acid to the total volume of the aqueous solution of the acid;

and/or in the application step (2) for back-extracting lithium from lithium-containing brine, the acid in the acid aqueous solution is an inorganic acid, and the inorganic acid is one or more of hydrochloric acid, sulfuric acid and nitric acid;

and/or in the application step (2) for stripping lithium from lithium-containing brine, the volume ratio of the lithium ion-loaded organic phase to the acid aqueous solution is 5:1-40: 1;

and/or in the application of extracting lithium from the lithium-containing brine or the application of back-extracting lithium from the lithium-containing brine, the ratio of magnesium to lithium in the lithium-containing brine is 16;

and/or, said lithium-containing brine, said Li⁺The concentration of (A) is 0.144mol/L-0.29 mol/L;

and/or, said lithium-containing brine, said Mg²⁺The concentration of (A) is 4mol/L-4.64 mol/L;

and/or, the lithium-containing brine, the Na⁺The concentration of (A) is 0.05mol/L-0.4 mol/L;

and/or, said lithium-containing brine, said K⁺The concentration of (A) is 0.02mol/L-0.4 mol/L;

and/or, said lithium-containing brine, said Cl^-The concentration of (A) is 9.2mol/L-10.7 mol/L;

and/or, said lithium-containing brine, said B₂O₃The concentration of (A) is 0.01mol/L-0.1 mol/L;

and/or the presence of a gas in the gas,in the lithium-containing brine, the hydrogen⁺The concentration of (b) is 0.05mol/L to 0.3 mol/L.

25. The use of claim 24, wherein in said use of extracting lithium from a lithium-containing brine or said use of extracting lithium from a lithium-containing brine in step (1), the volume ratio of said organic phase of the extraction composition to said lithium-containing brine is from 2:1 to 6: 1;

and/or in the application step (2) for stripping lithium from lithium-containing brine, the molar concentration of the aqueous solution of the acid is 6-8 mol/L, and the molar concentration refers to the ratio of the amount of substances of the acid to the total volume of the aqueous solution of the acid;

and/or in the application step (2) for stripping lithium from lithium-containing brine, the volume ratio of the lithium ion-loaded organic phase to the acid aqueous solution is 10:1-30: 1;

and/or, said lithium-containing brine, said Mg²⁺The concentration of (A) is 4.32 mol/L;

and/or, the lithium-containing brine, the Na⁺The concentration of (A) is 0.1 mol/L;

and/or, said lithium-containing brine, said Cl^-The concentration of (2) was 9.8 mol/L.