CN107447117A - A kind of extracts composition, extraction system, extracting process and back extraction method - Google Patents

Abstract

The invention discloses a kind of extracts composition, extraction system, extracting process and back extraction method.The extracts composition of the present invention includes：Extractant and neutral phosphorus oxygen class compound；The extractant includes N, (2 ethylhexyl) acetamides of N bis- and N, N bis- (2 ethylhexyl) 2 methyl propanamides.Extracts composition itself ph stability of the present invention is good, and aqueous phase dissolved degree is small, and density, viscosity are smaller, is required without the extracting operation, small to equipment corrosion of complexity, and suitable for industrialization running.

Description

A kind of extracts composition, extraction system, extracting process and back extraction method

Technical field

The present invention relates to a kind of extracts composition, extraction system, extracting process and back extraction method.

Background technology

Lithium not only has important application in national defense industry, and its importance in national economy is also increasingly evident It is aobvious, particularly in energy field：⁶Li and⁷Li is fuel and the nuclear fission of following fusion reactor respectively Important materials used in reaction；It is also growing as the demand of battery material.Therefore, lithium has " 21 The title of the energy metal in century ".Both at home and abroad to the demand sustainable growth of lithium, therefore lithium resource is ground Study carefully and utilization seem extremely urgent.

Salt lake bittern is the valuable source of lithium.China has abundant salt lake bittern lithium resource, its reserves It is at the forefront in the world.But due to containing various metals ion in bittern, it comprehensively utilizes and from bittern The technology of separation and Extraction lithium is to need the important topic studied, especially for containing high concentration magnesium, low dense Separation and Extraction lithium in so-called " high Mg/Li ratio " bittern of lithium is spent, is generally acknowledged worldwide technological puzzle.

Solvent extraction technology is the effective technology of the various metals of separation and Extraction from solution, and there is separation to imitate for it Rate is high, technique and equipment are simple, operates serialization, is easily achieved the advantages that automatically controlling, it is considered to be One of most promising method of separating Li is extracted from " high Mg/Li ratio " bittern.From 60 years last century Since for mid-term, some extraction systems and technique have been had been presented for both at home and abroad.1967, the hair such as Nelli J.R. Understand a kind of extraction system and technique [1.Nelli J.R.et al.Fr.1,535,818 (1967)； USP3,537,813(1970).]：FeCl is added in bittern₃As co-extraction agent, with 80% diisobutyl ketone -20% Tributyl phosphate (TBP) is used as organic phase, by Li and Fe with LiFeCl₄Form coextraction enters organic A large amount of MgCl in phase, with aqueous phase₂And other metals separation.Though extraction tool of the system to Li is higher Selectivity, but be stripped with water and produce LiCl and FeCl₃Mixed liquor, must with di-(2-ethylhexyl)phosphoric acid- Tributyl phosphate system extract and separate Li and Fe again, causes technique tediously long, cumbersome, so far not See that it is used for industrial production.1979, Qinghai Salt Lake research institute of the Chinese Academy of Sciences was proposed with single extractant phosphorus The system and technique of the kerosin extraction lithium of sour tributyl, so as to simplify extraction system, and in 1984 Carry out extracting the pilot-plant test of lithium year from big bavin denier salt lake bittern, apply for China in 1987 Patent of invention [3. yellow teachers are strong etc., Chinese invention patent, 87103431], and authorized.But Tributyl phosphate concentration is higher in the system, stronger to the corrosivity of extraction equipment, and in long-term operating The extractant not only solution loss in water, and tributyl phosphate is degraded in acid medium, especially It is that its serious swelling action to the material for making extraction equipment limits its industrial-scale application.

Chinese invention patent (CN103055539A) is disclosed using amides compound or amide-type Compound and the mixture of neutral phosphorus oxygen class compound are extractant, ferric trichloride be co-extraction agent and aliphatic hydrocarbon or Aromatic hydrocarbon is the method that diluent carries out lithium extraction.But for its disclosed specific method, in industrialization During it is still pure in problems, as single-stage extraction rate is relatively low, influence yield and yield, want to obtain compared with Extraction series must be increased in high yield；The separation factor of lithium and magnesium, sodium, potassium is not big enough, directly obtains Product can not reach high-purity requirement, it is necessary to increase washing series or other post processing modes.

The content of the invention

Problem to be solved by this invention is, in order to overcome the existing extraction that lithium is extracted from bittern containing lithium Agent is serious to equipment corrosion, the molten damage of extractant is big, the low yield of single-stage extraction rate is low, purifying products technique length The shortcomings of, and a kind of extracts composition, extraction system, extracting process and back extraction method are provided.This hair Itself ph stability of bright extracts composition is good, and aqueous phase dissolved degree is small, and density, viscosity are smaller, lithium extraction Take rate and back extraction ratio height, lithium and sodium potassium magnesium separation factor big, small to equipment corrosion, and suitable for industry Change running to require.

The invention provides a kind of extracts composition, and it is included：Extractant and neutral phosphorus oxygen class compound； The extractant includes：(2- ethylhexyls) acetamide of N, N- bis- and N, N- bis- (2- ethylhexyls) -2- methyl-props Acid amides；

Neutral phosphorus oxygen class compound formula structure is following (formula A)：

Wherein, R¹And R²It independently is straight chain or the C with side chain₁-C₁₂Alkyl, straight chain or with branch The C of chain₁-C₁₂Alkoxy, thienyl, pyridine radicals, naphthyl, substituted or unsubstituted phenyl, Huo Zhequ Generation or unsubstituted phenoxy group；

When described phenyl is substituted, substituent is selected from following one or more：Halogen, C₁-C₆Alkane Base, hydroxyl, C₁-C₆Alkoxy, trifluoromethyl, trifluoromethoxy, phenoxy group, piperidyl, morpholine Base, pyrrole radicals, nafoxidine base, nitro, amino；It is described when the substituent on phenyl is multiple Substituent it is identical or different；

When described phenoxy group is substituted, substituent is selected from following one or more：Halogen, C₁-C₆ Alkyl, hydroxyl, C₁-C₆Alkoxy, trifluoromethyl, trifluoromethoxy, phenoxy group, piperidyl, Quinoline base, pyrrole radicals, nafoxidine base, nitro, amino；When the substituent on phenoxy group is multiple, Described substituent is identical or different.

In described neutral phosphorus oxygen class compound, described " straight chain or the C with side chain₁-C₁₂Alkyl " is excellent Select " straight chain or the C with side chain₁-C₈Alkyl ", more preferably " straight chain or the C with side chain₄-C₈Alkyl ". Described " straight chain or the C with side chain₁-C₈Alkyl " preferably methyl, ethyl, n-propyl, isopropyl, Normal-butyl, isobutyl group, 1- methyl-heptyls or 2- ethyl hexyls.

In described neutral phosphorus oxygen class compound, described " straight chain or the C with side chain₁-C₁₂Alkoxy " It is preferred that " straight chain or the C with side chain₁-C₈Alkoxy ", more preferably " straight chain or the C with side chain₄-C₈Alkane Epoxide ".Described " straight chain or the C with side chain₁-C₈Alkoxy " preferably methoxyl group, ethyoxyl, positive third Epoxide, isopropoxy, n-butoxy, isobutoxy, 1- methyl-heptan epoxide or 2- ethyls-hexyloxy.

One kind or more in the described neutral preferred following compounds of phosphorus oxygen class compound as shown in formula A Kind：

In described extracts composition, described extractant and the volume ratio of neutral phosphorus oxygen class compound are preferred 7:1~1:8, more preferably 5:1-1:5, further preferred 4:1-1:2, most preferably 2:1-1:1, it is further excellent Select 3:2.

In described extractant, (2- ethylhexyls) acetamide of N, N- bis- and N, N- bis- (2- ethylhexyls) -2- The volume ratio of methyl propanamide preferably 10:1~1:10, more preferably 5:1-1:6, most preferably 3:1-1:2 (such as 2:1-1:1)。

Other amides compounds, other described amides compounds are may also include in described extractant It is preferred that N, N- dihexyl acetamide, N, N- dihexyls propionamide, N, N- dihexyl -2- methyl propanamides, N, N- dihexyl benzamide, N, N- dihexyls are to methyl benzamide and N, in N- dihexyl butanamides One or more：

In described extractant, when containing other amides compounds, other described amide-type chemical combination The dosage of thing does not have particular/special requirement, as long as not influenceing extraction and the back extraction performance of described extractant. In described extractant, when containing other amides compounds, described N, N- bis- (2- ethylhexyls) Acetamide and N, N- bis- (2- ethylhexyls) content of -2- methyl propanamides in extractant are preferred 0.01%-99.9%, more preferably 75%-85.6%, most preferably 80%.In described extractant, when containing During other amides compounds, (2- ethylhexyls) acetamide of described N, N- bis- and (the 2- ethyl hexyls of N, N- bis- Base) -2- methyl propanamides cumulative volume and other amides compounds volume ratio preferably 3:1-7:1, it is more excellent Select 4:1.

Diluent is preferably also included in described extracts composition, described diluent can be that this area is conventional Diluent.Under the preferred normal pressure of described diluent boiling point equal to or higher than 100 DEG C aliphatic hydrocarbon (such as Dodecane) or aromatic hydrocarbon, or kerosene.The preferred 10%-80% of dosage of described diluent, enters The preferred 20%-60% of one step, most preferably 30%-40%, percentage is diluent relative to extracts composition The percentage by volume of cumulative volume.

Co-extraction agent is preferably also included in described extracts composition, described co-extraction agent can be first in extraction It is dissolved in aqueous phase, first can also stabilizes it in organic phase.Described co-extraction agent refers generally to substantially to carry The molysite of the positive trivalent of high lithium extraction yield, can be ferric trichloride, ferric sulfate, ferric nitrate and/or ferric phosphate Deng preferred ferric trichloride.The dosage of described co-extraction agent can be according to the content of lithium ion in material to be extracted To determine, the mol ratio preferably 1 of ferric ion and lithium ion in material to be extracted in general co-extraction agent:1-2:1, Further preferred 1.5:1-1.75:1, more preferably 1.3:1-1.1:1.Described material to be extracted preferably bittern containing lithium.

When in described extracts composition except extractant and neutral phosphorus oxygen class compound also comprising other into Timesharing, the total content of described extractant and neutral phosphorus oxygen class compound in extracts composition organic phase are excellent Elect 20%-90%, more preferably 40%-80%, most preferably 60%-70% (percentage by volume) as.

Described extractant can be by N, (2- ethylhexyls) acetamides of N- bis- and N, N- bis- (2- ethylhexyls) -2- Methyl propanamide forms.Described extractant can also be by N, (2- ethylhexyls) acetamides of N- bis- and N, N- Two (2- ethylhexyls) -2- methyl propanamides, and N, N- dihexyl acetamide, N, N- dihexyls propionamide, N, N- dihexyl -2- methyl propanamides, N, N- dihexyls benzamide, N, N- dihexyls are to toluyl One or more compositions in amine and N, N- dihexyl butanamide.

Neutral phosphorus oxygen of the described extracts composition further preferably as described extractant, as shown in formula A Class compound and described diluent composition.

Neutral phosphorus oxygen class of the described extracts composition more preferably as described extractant, as shown in formula A Compound, described diluent and described co-extraction agent composition.

Present invention also offers a kind of extraction system, and it includes described extracts composition and bittern containing lithium.

In described extraction system, the bittern containing lithium can be the conventional bittern containing lithium in this area, this hair The bright preferably bittern containing lithium containing high Mg/Li ratio, described high Mg/Li ratio refer generally to Mg in bittern containing lithium²⁺/Li⁺ Mol ratio between 2~30, preferably 16.Described bittern containing lithium can include：0.02mol/L-2.0mol/L Li⁺, 2.0mol/L-5.0mol/L Mg²⁺, 0mol/L-0.5mol/L Na⁺、0mol/L-0.5mol/L K⁺, >=6mol/L Cl^-, 0mol/L-0.90mol/L B₂O₃With 0.001mol/L-0.5mol/L's H⁺(bittern acidity).Described bittern containing lithium preferably comprises：0.144mol/L-2.0mol/L Li⁺、 4mol/L-4.64mol/L Mg²⁺, 0.05mol/L-0.4mol/L Na⁺、0.02mol/L-0.4mol/L K⁺, 9.2-10.7mol/L Cl^-, 0mol/L-0.1mol/L B₂O₃And 0.04mol/L-0.3mol/L H⁺(bittern acidity).Described bittern containing lithium more preferably includes：0.29mol/L-2.0mol/L Li⁺、 4mol/L-4.32mol/L Mg²⁺, 0.05mol/L-0.1mol/L Na⁺、0.02mol/L-0.4mol/L K⁺, 9.8-10.7mol/L Cl^-, 0mol/L-0.01mol/L B₂O₃And 0.04mol/L-0.05mol/L H⁺(bittern acidity).

In described extraction system, described extracts composition organic phase (organic phase) and (water of bittern containing lithium Phase) volume ratio preferably 1:5-10:1, more preferably 1:2-6:1, most preferably 1:1-2:1.

In described extraction system, if described extracts composition contains co-extraction agent, described co-extraction agent exists Preferred 0.05mol/L-the 3.5mol/L of concentration in bittern containing lithium.

Present invention also offers a kind of extracting process, and it comprises the following steps：Combined using described extraction Thing extracts to bittern containing lithium.

Described extracting process can be the method for the conventional extraction lithium in this area, preferably include the following steps： Organic phase containing diluent, described extractant and neutral phosphorus oxygen class compound and the agent containing co-extraction are contained into lithium Bittern mixes, vibration or stirring balance, stratification.Wherein, by vibrating or stirring mass transfer.

In described extracting process, the temperature of organic phase and aqueous phase be preferably 10 DEG C -50 DEG C (preferably 20-40 DEG C, more preferably 25 DEG C -30 DEG C), i.e., extracted at 10 DEG C -50 DEG C.

Described extracting process can also be by extraction equipments such as centrifugal extractor, mixer-settler, extraction towers Complete mass transfer and phase process.Described centrifugal extractor, mixer-settler, extraction tower can be ability The conventional extraction equipment in domain, its use condition and method can refer to extracts the normal of lithium from the aqueous solution containing lithium Advise use condition and method.

Present invention also offers a kind of back extraction method, it comprises the following steps：Will be through above-mentioned extracting process The organic phase containing lithium obtained mixes with the aqueous solution of acid, vibration or stirring balance, stratification.Wherein, The lithium of organic phase load is transferred to aqueous phase.

In described back extraction method, the molar concentration of the described sour aqueous solution is preferably 0.5mol/L-12mol/L, it is more preferably 4-10mol/L, most preferably 6-8mol/L, described molar concentration Refer to that the amount of the material of acid accounts for the ratio of the aqueous solution cumulative volume of acid.

In described back extraction method, the acid in the described sour aqueous solution can be the conventional acid in this area, Preferably inorganic acid.Described inorganic acid is preferably one kind in hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid Or it is a variety of, it is more preferably hydrochloric acid.

In described back extraction method, the volume ratio of the organic phase containing lithium and the aqueous solution of acid can be this The conventional volume ratio in field, such as 1:1-50:1, preferably 5:1-40:1, more preferably 10:1-30:1.

Described back extraction method is preferably carried out at 10-50 DEG C, more preferably 24-25 DEG C.

In the present invention, organic phase refer to compared with aqueous phase not by co-extraction agent be contained in in the case of, organic phase with The volume ratio of aqueous phase.

In the present invention, described normal pressure refers to 1 atmospheric pressure, 101.325kPa.

Without prejudice to the field on the basis of common sense, above-mentioned each optimum condition, can be combined, and produce this Invent each preferred embodiments.

Agents useful for same and raw material of the present invention are commercially available.

The positive effect of the present invention is：Extractant itself ph stability is good, water-soluble, density With the smaller loss reduced in extraction process of viscosity, the purity for the lithium being obtained by extraction is improved, is overcome existing Have the shortcomings that the extractant that lithium is extracted from bittern containing lithium is serious to equipment corrosion, the molten damage of extractant is big.This Single-stage extraction rate and back extraction ratio height, lithium and sodium of extracts composition, extraction system and the method for invention to lithium Potassium magnesium separation factor is big, high income, purifying products are easy, is required suitable for industrialization running.

Embodiment

The present invention is further illustrated below by the mode of embodiment, but is not therefore limited the present invention to Among described scope of embodiments.The experimental method of unreceipted actual conditions in the following example, according to normal Rule method and condition, or selected according to catalogue.

The number being related in the following example refers both to volume parts.

Unless defined, the term being related in the present invention is explained as follows：

1st, compare

For interrupted extraction process, organic phase volume V (m are extracted³) and feed liquid aqueous phase L (m³) the ratio between be referred to as Compare；For continuous extraction process, extraction phase volume flow V (m³/ s) and feed liquid phase volume flow L (m³/s) The ratio between also referred to as compare or two-phase flow ratio, it is unified herein to represent two-phase volume or flow with O/A.Compare Represented with R：

In formula：V_oFor the volume of extraction phase, V_aFor the volume of feed liquid phase

2nd, extraction yield

Extraction yield, which represents to be extracted material in extraction process the amount of extraction phase is mutually transferred to by feed liquid, to be accounted for and is extracted The percentage of material total amount in raw material liquid phase, it represents the degree of extract and separate.Extraction yield E (%) meter Calculating formula is：

In formula：n_aTo be extracted the amount of material, n in feed liquid_oTo be extracted the amount of material in extraction raffinate.

3rd, distribution ratio

Distribution ratio is also known as distribution coefficient.Distribution behavior of the substance A in two-phase is extracted to can be understood as The gross effect of A the variform A1 present in two-phase, A2 ..., An distribution.Under normal conditions, Measured value of experiment is extracted the total concentration of a variety of existing forms of material in representing per phase.System distribution coefficient is determined Justice is under certain condition, when system reaches balance, to be extracted material in extraction organic phase (O) The ratio between total concentration and total concentration in feed liquid phase (A), are represented with D：

Distribution ratio represents that extraction system is extracted actual allocation proportion of the material in two-phase after reaching balance, Typically by measuring.It is bigger by the distribution ratio of extraction thing, show that the material is more easily extracted, distribute simultaneously The size of ratio is also relevant with extraction conditions except with being had outside the Pass by the property of extraction thing, as in aqueous phase by extraction thing Concentration, acidity, the other materials coexisted, the species and concentration of extractant, the kind of diluent in organic matter Temperature when class and extraction etc. is relevant.

4th, separation factor

When carrying out extract and separate under certain condition, two kinds of materials to be separated are in two alternate distribution coefficients Ratio, referred to as extract and separate factor, also known as extract and separate coefficient, commonly use β and represent.If A, B distinguishes Two kinds of materials to be separated are represented, then are had：

In formula：D_AFor the distribution ratio of A materials, D_BFor the distribution ratio of B substance.

Extract and separate quantifies illustrate the difficulty or ease of two kinds of materials in some extraction system separating material liquid phase Degree.Both materials can not be separated when β value is 1, and β value is bigger or smaller, and separating effect is got over Good, i.e. the separation selectivity of extractant is higher.

Embodiment 1

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- The content of (2- ethylhexyls) -2- methyl propanamides, TBP in kerosin is respectively 25%, 5%, 30% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is taken, adds FeC1₃As co-extraction agent, make Fe in aqueous phase³⁺/Li⁺Mol ratio is 1.3, fully dissolving.Add 2 parts of above-mentioned organic phase (extraction phase ratio, organic phases/aqueous phase, i.e. O/A=2:1), Two-phase is sufficiently mixed under the conditions of 25 DEG C to be extracted.After mixing terminates, stratification, split-phase effect Good, aqueous phase is colourless, and two-phase interface is clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺、 Mg²⁺Concentration, the extraction yield for thus calculating Li are 84.58%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution Than being respectively 2.743,0.038,0.041,0.00558.Li/Mg, Li/Na and Li/K separation Respectively 491,72.2,66.9.

Embodiment 2

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- The content of (2- ethylhexyls) -2- methyl propanamides, TBP in kerosin is respectively 10%, 60%, 10% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is added in a separatory funnel, adds FeC1₃As co-extraction agent, make in aqueous phase Fe³⁺/Li⁺Mol ratio is 1.1,1 part of above-mentioned organic phase (comparing O/A=1/1) is added, in 25 DEG C of bars Two-phase is sufficiently mixed under part to be extracted.After mixing terminates, stratification, split-phase effect is good, aqueous phase Colourless, two-phase interface is clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺And Mg²⁺, Thus the extraction yield for calculating Li is 85.36%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution ratio be respectively 5.831, 0.096、0.109、0.0116.Li/Mg, Li/Na and Li/K separation are respectively 503,60.7, 53.5。

Embodiment 3

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- The content of (2- ethylhexyls) -2- methyl propanamides, TBP in kerosin is respectively 5%, 5%, 80% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is added in a separatory funnel, adds FeC1₃As co-extraction agent, make in aqueous phase Fe³⁺/Li⁺Mol ratio is 1.75, adds 6 parts of above-mentioned organic phases and (is compared as extracts composition O/A=6/1), it is sufficiently mixed two-phase under the conditions of 40 DEG C to be extracted.After mixing terminates, stand and divide Layer, split-phase effect is good, and aqueous phase is colourless, and two-phase interface is clear.Measure respectively in balance aqueous phase and organic phase Li⁺、Na⁺、K⁺And Mg²⁺, the extraction yield for thus calculating Li is 92.89%, Li⁺、Na⁺、K⁺With Mg²⁺Distribution ratio be respectively 2.177,0.016,0.024,0.00253.Li/Mg, Li/Na and Li/K Separation be respectively 861,136.1,90.7.

Embodiment 4

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- The content of (2- ethylhexyls) -2- methyl propanamides, trioctyl phosphate in kerosin is respectively 25%, 25%th, 10% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is taken, adds FeC1₃As co-extraction agent, make the Fe in aqueous phase³⁺/Li⁺Mol ratio For 1.3, fully dissolving.Adding 2 parts of above-mentioned organic phases, (extraction phase compares O/A=2:1), in 25 DEG C of conditions Under two-phase is sufficiently mixed extracted.Mixing terminate after, stratification, split-phase effect is good, aqueous phase without Color, two-phase interface are clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺、Mg²⁺Concentration, Thus the extraction yield for calculating Li is 83.55%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution ratio be respectively 2.540, 0.024、0.036、0.00468.Li/Mg, Li/Na and Li/K separation are respectively 543,105.8, 70.5。

Embodiment 5

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- The content of (2- ethylhexyls) -2- methyl propanamides, di-iso-octylmethylphosphonate in kerosene is respectively 10%, 10%th, 20% (each composition accounts for the percentage of organic phase cumulative volume).

1 part of bittern containing lithium is taken, adds FeC1₃As co-extraction agent, make the Fe in aqueous phase³⁺/Li⁺Mol ratio For 1.3, fully dissolving.Adding 2 parts of above-mentioned organic phases, (extraction phase compares O/A=2:1), in 25 DEG C of conditions Under two-phase is sufficiently mixed extracted.Mixing terminate after, stratification, split-phase effect is good, aqueous phase without Color, two-phase interface are clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺、Mg²⁺Concentration, Thus the extraction yield for calculating Li is 83.25%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution ratio be respectively 2.485, 0.042、0.037、0.00475.Li/Mg, Li/Na and Li/K separation are respectively 523,59.2, 67.2。

Embodiment 6

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- (2- ethylhexyls) -2- methyl propanamides, N, the content difference of N- dihexyls acetamide, TBP in kerosene For 20%, 10%, 10%, 10% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is taken, adds FeC1₃As co-extraction agent, make the Fe in aqueous phase³⁺/Li⁺Mol ratio For 1.5, fully dissolving.Adding 2 parts of above-mentioned organic phases, (extraction phase compares O/A=2:1), in 25 DEG C of conditions Under two-phase is sufficiently mixed extracted.Mixing terminate after, stratification, split-phase effect is good, aqueous phase without Color, two-phase interface are clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺、Mg²⁺Concentration, Thus the extraction yield for calculating Li is 88.95%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution ratio be respectively 4.025, 0.043、0.058、0.00687.Li/Mg, Li/Na and Li/K separation are respectively 586,93.6, 69.4。

Embodiment 7

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- (2- ethylhexyls) -2- methyl propanamides, N, N- dihexyl -2- methyl propanamides, TBP are in kerosin Content be respectively 10%, 60%, 10%, 10% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is taken, adds FeC1₃As co-extraction agent, make the Fe in aqueous phase³⁺/Li⁺Mol ratio For 1.1, fully dissolving.Adding 2 parts of above-mentioned organic phases, (extraction phase compares O/A=2:1), in 25 DEG C of conditions Under two-phase is sufficiently mixed extracted.Mixing terminate after, stratification, split-phase effect is good, aqueous phase without Color, two-phase interface are clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺、Mg²⁺Concentration, Thus the extraction yield for calculating Li is 84.17%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution ratio be respectively 2.659, 0.038、0.041、0.00459.Li/Mg, Li/Na and Li/K separation are respectively 579,70.0, 64.8。

Embodiment 8

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- (2- ethylhexyls) -2- methyl propanamides, N, N- dihexyls are to methyl benzamide, TBP in kerosin In content be respectively 30%, 10%, 10%, 10% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is taken, adds FeC1₃As co-extraction agent, make the Fe in aqueous phase³⁺/Li⁺Mol ratio For 1.5, fully dissolving.Adding 2 parts of above-mentioned organic phases, (extraction phase compares O/A=2:1), in 25 DEG C of conditions Under two-phase is sufficiently mixed extracted.Mixing terminate after, stratification, split-phase effect is good, aqueous phase without Color, two-phase interface are clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺、Mg²⁺Concentration, Thus the extraction yield for calculating Li is 89.56%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution ratio be respectively 4.289, 0.047、0.069、0.00692.Li/Mg, Li/Na and Li/K separation are respectively 620,91.3, 62.2。

Embodiment 9

Bittern containing lithium forms：

Organic phase：Using kerosene as diluent, compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- (2- ethylhexyls) -2- methyl propanamides, N, N- dihexyls butanamide, TBP containing in kerosin Amount is respectively 10%, 20%, 10%, 10% (each composition accounts for the percentage of organic phase cumulative volume)；

1 part of bittern containing lithium is taken, adds FeC1₃As co-extraction agent, make the Fe in aqueous phase³⁺/Li⁺Mol ratio For 1.5, fully dissolving.Adding 2 parts of above-mentioned organic phases, (extraction phase compares O/A=2:1), in 25 DEG C of conditions Under two-phase is sufficiently mixed extracted.Mixing terminate after, stratification, split-phase effect is good, aqueous phase without Color, two-phase interface are clear.Li in balance aqueous phase and organic phase is measured respectively⁺、Na⁺、K⁺、Mg²⁺Concentration, Thus the extraction yield for calculating Li is 86.42%, Li⁺、Na⁺、K⁺And Mg²⁺Distribution ratio be respectively 3.182, 0.036、0.048、0.00444.Li/Mg, Li/Na and Li/K separation are respectively 717,88.4, 66.3。

Embodiment 10

Bittern containing lithium forms：

Organic phase：Compound N, N- bis- (2- ethylhexyls) acetamide, N, N- bis- (2- ethylhexyls) -2- methyl Propionamide, TBP content are respectively that 30%, 30%, 40% (each composition accounts for the hundred of organic phase cumulative volume Divide ratio)；

2 parts of above-mentioned organic phases are taken, by Fe in aqueous phase³⁺/Li⁺Mol ratio is 2, is added into the organic phase FeC1₃.1 part of bittern containing lithium is taken, contains FeC1 with above-mentioned₃Organic phase (extraction phase compares O/A=2:1) Mix, be sufficiently mixed two-phase under the conditions of 40 DEG C and extracted.After mixing terminates, stratification, point Phase effect is good, and aqueous phase is colourless, and two-phase interface is clear.Li in balance aqueous phase and organic phase is measured respectively⁺、 Na⁺、K⁺、Mg²⁺Concentration, the extraction yield for thus calculating Li are 90.63%, Li⁺、Na⁺、K⁺With Mg²⁺Distribution ratio be respectively 4.836,0.051,0.074,0.00789.Li/Mg, Li/Na and Li/K Separation be respectively 613,94.8,65.4.

Comparative example 1~3

Organic phase is replaced with into N, (2- the ethylhexyls) -2- of (2- ethylhexyls) acetamides of N- bis-+N, N- bis- respectively (the 2- ethyl hexyls of hydroxyl acetamide+TBP kerosin, N, N- bis- (2- ethylhexyls) acetamide+N, N- bis- Base) t-butyl carboxamide+TBP kerosin, N, (the 2- ethyl hexyls of (2- ethylhexyls) acetamides of N- bis-+N, N- bis- Base) -2- ethojqracetamides+TBP kerosin, remaining operation and condition with embodiment 1.Experiment knot Fruit is as shown in the table：

Embodiment 11 (back extraction)

One effective extraction system, excellent extraction ability is not only required, and had good It is stripped performance.

Organic phase：The organic phase containing lithium ion that embodiment 2,4,9 obtains；

Aqueous phase：The aqueous hydrochloric acid solution of different molar concentrations；

By the combined of the organic phase containing lithium ion and different molar concentrations, (mixed proportion is shown in Table 1), vibrated 10 minutes at 24 DEG C, stratification, Li in measure balance two-phase⁺Concentration.Design parameter See below list 1.

Comparative example 4 and 5：N in patent CN103055539A, N- bis- (2- ethylhexyls) acetamide+TBP, TBP is stripped Example, and actual conditions is as follows：The organic phase of 30 parts of extraction back loading lithiums is taken, is added 1 part of 6mol/L HCl (comparing O/A=30), vibrate 10 minutes, temperature is 24 DEG C of room temperature, is stripped Take, stratification.Determine the Li concentration in stripping equilibria organic phase and aqueous phase.

Table 1

The preparation of the extractant of embodiment 12

Universal preparation method：Equipped with thermometer, constant pressure funnel, churned mechanically 2L three In neck bottle, amine reactant 1mol, 400mL dichloromethane and 153mL (1.1mol) are separately added into Triethylamine, stirring is opened, and system is cooled to 0 DEG C, while by 1.05mol acyl chlorides and about 200mL Dichloromethane solution be placed in dropping funel and start to be added dropwise, keep system temperature be no more than 15 DEG C, about It is added dropwise within 30 minutes.Ice bath is removed, room temperature reaction is overnight.Add consolidating for isometric water dissolving generation Body, after separatory funnel layering, organic phase watery hydrochloric acid and saturated common salt water washing, and use anhydrous sodium sulfate Dry, after desolvation, be evaporated under reduced pressure.

N, N- bis- (2- ethylhexyls) acetamide：

Amine reactant：Diisooctyl amine；Acyl chlorides：Chloroacetic chloride.Yield:90%；138~143 DEG C /9×10^-2mba；¹H NMR(400MHz,CDCl₃)δ3.13-3.34(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)；¹³C NMR (100MHz,CDCl₃)δ170.903,52.095,48.311,38.284,36.898,30.561,30.473, 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.

N, N- bis- (2- ethylhexyls) -2- methyl propanamides：

Amine reactant：Diisooctyl amine；Acyl chlorides：2- methyl propionyl chlorides.Yield:90%；138~146 DEG C /1.6×10^-2mba；¹H NMR(400MHz,CDCl₃)δ3.19-3.30(m,2H),3.15(d,2H), 2.77-2.83(m,1H),1.66-1.70(m,1H),1.53-1.56(m,1H),1.17-1.35(m,16H), 1.10(s,3H),1.11(s,3H),0.84-0.90(m,12H)；¹³C NMR(100MHz,CDCl₃)δ 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.

N, N- dihexyl acetamide：

Amine reactant：Dihexyl amine；Acyl chlorides：Chloroacetic chloride.Yield:97%；130~142 DEG C/6 × 10^-2mba；¹H NMR(400MHz,CDCl₃)δ3.27(t,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)；¹³C NMR(100MHz,CDCl₃)δ 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.

N, N- dihexyl propionamide：

Amine reactant：Dihexyl amine；Acyl chlorides：Propionyl chloride.Yield:97%；114~126 DEG C/6 × 10^-2mba；¹H NMR(400MHz,CDCl₃)δ3.13-3.35(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)；¹³C NMR(100MHz, CDCl₃)δ173.373,47.913,45.992,31.544,31.464,29.003,27.702,26.609, 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.

N, N- dihexyl -2- methyl propanamides：

Amine reactant：Dihexyl amine；Acyl chlorides：2- methyl propionyl chlorides.Yield:94%；130~138 DEG C /5.8×10^-2mba；¹H NMR(400MHz,CDCl₃)δ3.19-3.30(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)；¹³C NMR(100MHz,CDCl₃)δ176.821,31.544,30.119,26.571,22.558, 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.

N, N- dihexyl benzamide：

Amine reactant：Dihexyl amine；Acyl chlorides：Chlorobenzoyl chloride.Yield:95%；138~148 DEG C /7×10^-2mba；¹H NMR(400MHz,CDCl₃)δ7.34-7.37(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(100MHz,CDCl₃)δ171.638,137.296,134.523,130.549,128.992, 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.

N, N- dihexyl are to methyl benzamide：

Amine reactant：Dihexyl amine；Acyl chlorides：4- methyl benzoyl chlorides.Yield:96%；150~170 DEG C /7×10^-2mba；¹H NMR(400MHz,CDCl₃)δ7.16-7.18(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)；¹³C NMR(100MHz,CDCl₃)δ171.832,138.970, 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.

N, N- dihexyl butanamide：

Amine reactant：Dihexyl amine；Acyl chlorides：N-butyryl chloride.Yield:93%；126~136 DEG C /6×10^-2mba；¹H NMR(400MHz,CDCl₃)δ3.12-3.27(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)；¹³C NMR(100MHz,CDCl₃)δ172.599,47.991,47.952,45.907,34.953,31.529, 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.

Claims (14)

1. a kind of extracts composition, it is included：Extractant and neutral phosphorus oxygen class compound；The extraction Agent includes：(2- ethylhexyls) acetamide of N, N- bis- and N, N- bis- (2- ethylhexyls) -2- methyl propanamides；

Neutral phosphorus oxygen class compound formula structure is as shown in formula A：

Wherein, R¹And R²It independently is straight chain or the C with side chain₁-C₁₂Alkyl, straight chain or with branch The C of chain₁-C₁₂Alkoxy, thienyl, pyridine radicals, naphthyl, substituted or unsubstituted phenyl, Huo Zhequ Generation or unsubstituted phenoxy group；

When described phenyl is substituted, substituent is selected from following one or more：Halogen, C₁-C₆Alkane Base, hydroxyl, C₁-C₆Alkoxy, trifluoromethyl, trifluoromethoxy, phenoxy group, piperidyl, morpholine Base, pyrrole radicals, nafoxidine base, nitro, amino；It is described when the substituent on phenyl is multiple Substituent it is identical or different；

When described phenoxy group is substituted, substituent is selected from following one or more：Halogen, C₁-C₆ Alkyl, hydroxyl, C₁-C₆Alkoxy, trifluoromethyl, trifluoromethoxy, phenoxy group, piperidyl, Quinoline base, pyrrole radicals, nafoxidine base, nitro, amino；When the substituent on phenoxy group is multiple, Described substituent is identical or different.

2. extracts composition as claimed in claim 1, it is characterised in that：Described neutral phosphorus oxygen class In compound, described " straight chain or the C with side chain₁-C₁₂Alkyl " is " straight chain or with side chain C₁-C₈Alkyl ", preferably " straight chain or the C with side chain₄-C₈Alkyl ", more preferably methyl, ethyl, just Propyl group, isopropyl, normal-butyl, isobutyl group, 1- methyl-heptyls or 2- ethyl hexyls；

And/or in described neutral phosphorus oxygen class compound, described " straight chain or the C with side chain₁-C₁₂ Alkoxy " is " straight chain or the C with side chain₁-C₈Alkoxy ", preferably " straight chain or the C with side chain₄-C₈ Alkoxy ", more preferably methoxyl group, ethyoxyl, positive propoxy, isopropoxy, n-butoxy, isobutyl Epoxide, 1- methyl-heptan epoxide or 2- ethyls-hexyloxy.

3. extracts composition as claimed in claim 1, it is characterised in that：

Described neutral phosphorus oxygen class compound is the one or more in following compounds：

4. extracts composition as claimed in claim 1, it is characterised in that：Described extracts composition In, the volume ratio of described extractant and neutral phosphorus oxygen class compound is 7:1~1:8, preferably 5:1-1:5, More preferably 4:1-1:2, most preferably 2:1-1:1, further preferred 3:2；

And/or in described extractant, (2- ethylhexyls) acetamide of N, N- bis- and (the 2- ethyl hexyls of N, N- bis- Base) -2- methyl propanamides volume ratio be 10:1~1:10, preferably 5:1-1:6, most preferably 3:1-1:2, enter One step preferably 2:1-1:1；

And/or other amides compounds are may also include in described extractant, other described amide-types The preferred N of compound, N- dihexyls acetamide, N, N- dihexyls propionamide, N, N- dihexyl -2- methyl propionyl Amine, N, N- dihexyls benzamide, N, N- dihexyls are to methyl benzamide and N, the positive butyryl of N- dihexyls One or more in amine：

5. extracts composition as claimed in claim 4, it is characterised in that：In described extractant, When containing other amides compounds, (2- ethylhexyls) acetamide of described N, N- bis- and the (2- of N, N- bis- Ethylhexyl) the content of -2- methyl propanamides in extractant be 0.01%-99.9%, preferably 75%-85.6%, More preferably 80%；

And/or in described extractant, when containing other amides compounds, (the 2- of described N, N- bis- Ethylhexyl) acetamide and N, N- bis- (2- ethylhexyls) -2- methyl propanamides cumulative volume and other acid amides The volume ratio of class compound is 3:1-7:1, preferably 4:1；

And/or diluent is also included in described extracts composition, boiled under the preferred normal pressure of described diluent Aliphatic hydrocarbon (such as dodecane) or aromatic hydrocarbon of the point equal to or higher than 100 DEG C, or kerosene；

And/or co-extraction agent is also included in described extracts composition, the preferably positive trivalent of described co-extraction agent Molysite, can be ferric trichloride, ferric sulfate, ferric nitrate and/or ferric phosphate, preferably ferric trichloride；

And/or when in described extracts composition except extractant and neutral phosphorus oxygen class compound also include it During his composition, described extractant and neutral phosphorus oxygen class compound account for always containing in extracts composition organic phase It is percentage by volume to measure as 20%-90%, preferably 40%-80%, more preferably 60%-70%, percentage.

6. extracts composition as claimed in claim 5, it is characterised in that：

When also including diluent in described extracts composition, the dosage of described diluent is 10%-80%, preferably 20%-60%, more preferably 30%-40%, percentage are diluent relative to extraction The percentage by volume of composition cumulative volume；

When also including co-extraction agent in described extracts composition, the dosage of described co-extraction agent makes ferric iron The mol ratio of ion and lithium ion in material to be extracted is 1:1-2:1, further preferred 1.5:1-1.75:1, it is more excellent Select 1.3:1-1.1:1；Described material to be extracted preferably bittern containing lithium.

7. extracts composition as claimed in claim 1, it is characterised in that：

Described extractant is by N, (2- ethylhexyls) acetamides of N- bis- and N, N- bis- (2- ethylhexyls) -2- first Base propionamide forms；

It is preferred that described extractant is by N, (2- ethylhexyls) acetamides of N- bis- and (the 2- ethyl hexyls of N, N- bis- Base) -2- methyl propanamides, and N, N- bis- (2- ethylhexyls) -2- methyl propanamides, N, N- dihexyl second Acid amides, N, N- dihexyls propionamide, N, N- dihexyl -2- methyl propanamides, N, N- dihexyls benzamide, N, N- dihexyl are to methyl benzamide and N, one or more compositions in N- dihexyl butanamides；

It is preferred that neutral phosphorus oxygen class of the described extracts composition as described extractant, as shown in formula A Compound and described diluent composition；

It is preferred that neutral phosphorus oxygen class of the described extracts composition as described extractant, as shown in formula A Compound, described diluent and described co-extraction agent composition.

8. a kind of extraction system, it include extracts composition as described in any one of claim 1~7 and Bittern containing lithium.

9. extraction system as claimed in claim 8, it is characterised in that：In described extraction system, Described bittern containing lithium is the bittern containing lithium containing high Mg/Li ratio, and described high Mg/Li ratio is in bittern containing lithium Mg²⁺/Li⁺Mol ratio between 2~30, preferably 16；

Described bittern containing lithium can include：0.02mol/L-2.0mol/L Li+, 2.0mol/L-5.0mol/L Mg²⁺, 0mol/L-0.5mol/L Na⁺, 0mol/L-0.5mol/L K⁺, >=6mol/L Cl^-、 0mol/L-0.90mol/L B₂O₃With 0.001mol/L-0.5mol/L H⁺；Described bittern containing lithium is excellent Choosing includes：0.144mol/L-2.0mol/L Li⁺, 4mol/L-4.64mol/L Mg²⁺、 0.05mol/L-0.4mol/L Na⁺, 0.02mol/L-0.4mol/L K⁺, 9.2-10.7mol/L Cl^-、 0mol/L-0.1mol/L B₂O₃With 0.04mol/L-0.3mol/L H⁺；Described bittern containing lithium is more excellent Choosing includes：0.29mol/L-2.0mol/L Li⁺, 4mol/L-4.32mol/L Mg²⁺、 0.05mol/L-0.1mol/L Na⁺, 0.02mol/L-0.4mol/L K⁺, 9.8-10.7mol/L Cl^-、 0mol/L-0.01mol/L B₂O₃With 0.04mol/L-0.05mol/L H⁺；

In described extraction system, described extracts composition organic phase and the volume ratio of the bittern containing lithium are preferred 1:5-10:1, more preferably 1:2-6:1, most preferably 1:1-2:1；

In described extraction system, if described extracts composition contains co-extraction agent, described co-extraction agent exists Preferred 0.05mol/L-the 3.5mol/L of concentration in bittern containing lithium.

10. a kind of extracting process, it comprises the following steps：Using as described in any one of claim 1~7 Extracts composition bittern containing lithium is extracted.

11. extracting process as claimed in claim 10, it is characterised in that：When described extraction is combined When thing includes diluent and co-extraction agent, described extracting process comprises the following steps：Diluent, institute will be contained The extractant and the described extracts composition organic phase of neutral phosphorus oxygen class compound stated and the agent containing co-extraction Bittern containing lithium mixes, vibration or stirring balance, stratification.

12. extracting process as claimed in claim 10, it is characterised in that：

In described extracting process, the temperature of extracts composition organic phase and the bittern containing lithium is 10 DEG C -50 DEG C, It is preferred that 20-40 DEG C, more preferably 25 DEG C -30 DEG C.

13. a kind of back extraction method, it comprises the following steps：Will be through any one of such as claim 10~12 The organic phase containing lithium that described extracting process obtains mixes with the aqueous solution of acid, vibration or stirring balance, quiet Put layering.

14. back extraction method as claimed in claim 13, it is characterised in that：

In described back extraction method, the molar concentration of the described sour aqueous solution is 0.5mol/L-12mol/L, preferably 4-10mol/L, preferably 6-8mol/L, described molar concentration are The amount for referring to the material of acid accounts for the ratio of sour aqueous solution cumulative volume；

And/or in described back extraction method, the acid in the described sour aqueous solution is inorganic acid；It is described Inorganic acid be preferably one or more in hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, be more preferably hydrochloric acid；

And/or in described back extraction method, the organic phase containing lithium and the volume ratio of the aqueous solution of acid For 1:1-50:1, preferably 5:1-40:1, more preferably 10:1-30:1；

And/or described back extraction method is carried out at 10-50 DEG C, preferably 24-25 DEG C.