阅读说明：本技术 一种萃取剂及制备方法和分离稀土元素钇与镧系的方法 (Extracting agent, preparation method thereof and method for separating rare earth element yttrium from lanthanide ) 是由 王艳良 林锦池 吴玉远 肖文涛 于 2020-12-03 设计创作，主要内容包括：本发明属于稀土资源回收领域,提供了一种萃取剂,包括烷基苯基氧代丁酸；所述烷基苯基氧代丁酸包括式(I)和/或式(II)结构化合物中的一种或几种,其中,R-1、R-2和R-3独立的选自C1～C12的烷基。本发明提供的烷基苯基氧代丁酸萃取剂可直接应用于稀土金属离子的萃取分离,特别是稀土金属钇与其他镧系稀土金属离子的分离,具有良好的分离效果。本发明还提供了萃取剂的制备方法和分离稀土元素钇与镧系的方法。(The invention belongs to the field of rare earth resource recovery, and provides an extractant, which comprises alkyl phenyl oxobutyric acid; the alkyl phenyl oxo butyric acid comprises one or more compounds with the structures shown in formula (I) and/or formula (II), wherein R 1 、R 2 And R 3 Independently selected from alkyl of C1-C12. The alkyl phenyl oxobutyric acid extracting agent provided by the invention can be directly applied to extraction separation of rare earth metal ions, particularly separation of rare earth metal yttrium and other lanthanide rare earth metal ions, and has a good separation effect. The invention also provides a preparation method of the extracting agent and a method for separating rare earth element yttrium from lanthanide.)

1. An extractant comprising an alkylphenyloxybutyric acid; the alkyl phenyl oxo butyric acid comprises one or more compounds in the structures of formula (I) and/or formula (II):

wherein R is₁、R₂And R₃Independently selected from alkyl of C1-C12.

2. The extractant of claim 1, wherein R is₁Selected from C6-C12 alkyl groups.

3. The extractant of claim 1, wherein R is₂And R₃Independently selected from C1-C6 alkyl.

4. The extractant of claim 1, comprising compounds of formula (I) and formula (II) in a molar ratio of 1: 0.001 to 1: 1000.

5. the preparation method of the extracting agent is characterized by comprising the following steps of:

a) mixing succinic anhydride, an organic solvent and aluminum trichloride to obtain a mixed solution;

b) reacting the mixed solution with alkylbenzene to obtain a reaction solution;

c) mixing the reaction solution with water to obtain an oil phase and a water phase;

d) and carrying out reduced pressure distillation on the oil phase to obtain the extractant.

6. The method of claim 5, wherein the alkylbenzene has a structure of formula (III) or formula (IV):

wherein R is₁，R₂And R₃Independently selected from alkyl of C1-C12.

7. The method for preparing the extractant according to claim 5, wherein the organic solvent is one or more selected from petroleum ether, heptane, octane, dichloromethane and chloroform.

8. A method of separating a rare earth element yttrium from a lanthanide comprising:

A) saponifying the extractant of any one of claims 1 to 4 with an inorganic base and mixing with an organic solvent to obtain a saponified extractant solution;

B) mixing the saponified extractant solution and the rare earth solution for extraction, so that yttrium is left in a water phase, and yttrium-depleted rare earth enters an organic phase;

the rare earth elements in the rare earth solution comprise yttrium and one or more of lanthanide elements.

9. The method for separating yttrium, a rare earth element, from lanthanides as claimed in claim 8, wherein said organic solvent is selected from one or more of toluene, xylene and sulfonated kerosene; the inorganic alkali is selected from one or more of ammonia water, sodium hydroxide and potassium hydroxide.

10. The method for separating yttrium, a rare earth element, from lanthanides according to claim 8, wherein the concentration of the rare earth element in the rare earth solution is 0.05-1.5 mol/L; the pH value of the rare earth solution is 1-7.

Technical Field

The invention belongs to the technical field of rare earth element separation, and particularly relates to an extracting agent, a preparation method of the extracting agent and a method for separating rare earth element yttrium from lanthanide.

Background

In the field of rare earth metal element separation, naphthenic acid is mainly used as an extractant to extract and separate yttrium element from a rare earth metal mixture in the industry at present. Naphthenic acid is a byproduct in petrochemical industry, has limited source and complex components, can extract rare earth only under the condition of higher pH, and has easily changed components after long-term use, thereby influencing the stability of the separation process. Therefore, there is a need in the art to develop new extractants to replace commercial naphthenic acids.

Disclosure of Invention

In view of the above, the present invention aims to provide an extractant and a method for separating rare earth yttrium from lanthanide, and the extractant provided by the present invention has a good rare earth separation effect.

The invention provides an extractant, which comprises alkyl phenyl oxo-butyric acid; the alkyl phenyl oxo butyric acid comprises one or more compounds in the structures of formula (I) and/or formula (II):

wherein R is₁、R₂And R₃Independently selected from alkyl of C1-C12.

The alkyl phenyl oxo butyric acid can only comprise one or more compounds with the structure of formula (I), also can only comprise one or more compounds with the structure of formula (II), and also can simultaneously comprise one or more compounds with the structure of formula (I) and one or more compounds with the structure of formula (II).

Preferably, said R is₁Selected from C6-C12 alkyl groups.

Preferably, said R is₂And R₃Independently selected from C1-C6 alkyl.

Preferably, the compound comprises a compound with a structure shown in a formula (I) and/or a compound with a structure shown in a formula (II), wherein the molar ratio of the compound with a structure shown in the formula (I) to the compound with a structure shown in the formula (II) is 1: 0.001 to 1: 1000, parts by weight; or 1: 0.01-1: 100, respectively; or 1: 0.1-1: 10.

the invention provides a preparation method of an extracting agent, which comprises the following steps:

a) mixing succinic anhydride, an organic solvent and aluminum trichloride to obtain a mixed solution;

b) reacting the mixed solution with alkylbenzene to obtain a reaction solution;

c) mixing the reaction solution with water to obtain an oil phase and a water phase;

d) and carrying out reduced pressure distillation on the oil phase to obtain the extractant.

Preferably, the alkylbenzene has the structure of formula (III) or formula (IV):

wherein R is₁，R₂And R₃Independently selected from alkyl of C1-C12.

Preferably, the organic solvent is selected from one or more of petroleum ether, heptane, octane, dichloromethane and chloroform.

The invention also provides a method for separating rare earth element yttrium from lanthanide, which comprises the following steps:

A) saponifying the extracting agent in the technical scheme by using inorganic alkali, and mixing the saponifying agent with an organic solvent to obtain a saponified extracting agent solution;

B) mixing the saponified extractant solution and the rare earth solution for extraction, so that yttrium is left in a water phase, and yttrium-depleted rare earth enters an organic phase;

the rare earth elements in the rare earth solution comprise yttrium and one or more of lanthanide elements.

Preferably, the organic solvent is one or more selected from toluene, xylene and sulfonated kerosene.

Preferably, the inorganic base is selected from one or more of ammonia water, sodium hydroxide and potassium hydroxide.

Preferably, the concentration of the rare earth element in the rare earth solution is 0.05-1.5 mol/L.

Preferably, the pH value of the rare earth solution is 1-7.

The alkyl phenyl oxobutyric acid extracting agent provided by the invention has better chemical stability, simple synthesis and low price; compared with the industrial naphthenic acid, the extraction agent of the alkyl phenyl oxobutyric acid has obviously higher separation coefficient of La-Ho and yttrium ions (Y), close separation coefficient of Er, Tm, Yb and Lu and the yttrium ions (Y), and good separation effect of lanthanide ions and the yttrium ions, and is a potential novel extraction agent capable of replacing the naphthenic acid.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other examples, which may be modified or appreciated by those of ordinary skill in the art based on the examples given herein, are intended to be within the scope of the present invention. It should be understood that the embodiments of the present invention are only for illustrating the technical effects of the present invention, and are not intended to limit the scope of the present invention. In the examples, the methods used were all conventional methods unless otherwise specified.

The invention provides an extracting agent, which comprises alkyl phenyl oxo butyric acid. In the present invention, the extractant is preferably an extractant for separating rare earth, and more preferably an extractant for separating yttrium from lanthanide rare earth elements.

In the present invention, the alkylphenyloxybutyric acid includes one or more of the structures of formula (I) and/or formula (II):

wherein R is₁、R₂And R₃Independently selected from alkyl of C1-C12.

In the present invention, the alkylphenyloxybutyric acid may contain only one or more compounds having a structure represented by formula (I), may contain only one or more compounds having a structure represented by formula (II), and may contain both one or more compounds having a structure represented by formula (I) and one or more compounds having a structure represented by formula (II).

When the extracting agent comprises the compound with the structure shown in the formula (I) and/or the compound with the structure shown in the formula (II), the mol ratio of the compound with the structure shown in the formula (I) to the compound with the structure shown in the formula (II) is 1: 0.001 to 1: 1000, parts by weight; or 1: 0.01-1: 100, respectively; or 1: 0.1-1: 10.

in the present invention, said R₁Preferably a C1 alkyl group, C2 alkyl group, C3 alkyl group, C4 alkyl group, C5 alkyl group, C6 alkyl group, C7 alkyl group, C8 alkyl group, C9 alkyl group, C10 alkyl group, C11 alkyl group, C12 alkyl group, more preferably a methyl group, t-octyl group or dodecyl group; the R is₂Preferably C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, C9 alkyl, C10 alkyl, C11 alkyl, C12 alkyl, more preferably methyl or t-butyl; the R is₃Preferred are C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, C9 alkyl, C10 alkyl, C11 alkyl, C12 alkyl, and more preferred is methyl or t-butyl.

In the present invention, the preparation method of the extractant, specifically the preparation method of the alkylphenyl oxobutanoic acid, preferably includes the steps of:

a) mixing succinic anhydride, an organic solvent and aluminum trichloride to obtain a mixed solution;

b) reacting the mixed solution with alkylbenzene to obtain a reaction solution;

c) mixing the reaction solution with water to obtain an oil phase and a water phase;

d) and distilling the oil phase under reduced pressure to obtain the alkyl phenyl oxo-butyric acid (extractant).

In the present invention, the organic solvent used in the preparation of the mixed solution is preferably one or more selected from petroleum ether, heptane, octane, dichloromethane, and chloroform.

In the present invention, the aluminum trichloride is preferably anhydrous aluminum trichloride.

In the invention, the succinic anhydride, the organic solvent and the aluminum trichloride are preferably mixed under the condition of stirring, and the mixing temperature is preferably 20-30 ℃, and more preferably 25 ℃; the mixing time is preferably 5-15 min, and more preferably 10 min.

In the present invention, the alkylbenzene preferably has a structure of formula (III) or formula (IV):

wherein R is₁，R₂And R₃Independently selected from alkyl of C1-C12.

In the present invention, said R₁Preferably a C1 alkyl group, C2 alkyl group, C3 alkyl group, C4 alkyl group, C5 alkyl group, C6 alkyl group, C7 alkyl group, C8 alkyl group, C9 alkyl group, C10 alkyl group, C11 alkyl group, C12 alkyl group, more preferably a methyl group, t-octyl group or dodecyl group; the R is₂Preferably C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, C9 alkyl, C10 alkyl, C11 alkyl, C12 alkyl, more preferably methyl or t-butyl; the R is₃Preferred are C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, C9 alkyl, C10 alkyl, C11 alkyl, C12 alkyl, and more preferred is methyl or t-butyl.

In the present invention, the alkylbenzene is preferably one selected from the group consisting of di-tert-butylbenzene, tert-octylbenzene, dodecylbenzene and m-xylene.

In the invention, the mass ratio of the succinic anhydride, the organic solvent, the aluminum trichloride and the alkylbenzene is preferably (20-23): 100: 70: (40-45), more preferably (21-22): 100: 70: (42-43).

In the invention, the reaction temperature is preferably 20-30 ℃, and more preferably 25 ℃.

In the present invention, the reaction is preferably carried out under stirring; the reaction time is preferably 20-40 min, and more preferably 30 min.

In the invention, the water is preferably ice water, the water is preferably deionized water, and the mass ratio of the water to an organic solvent (succinic anhydride, the organic solvent and the organic solvent in the mixture of aluminum trichloride) is preferably (200-400): 100, more preferably (250-350): 100, most preferably 300: 100.

in the invention, the temperature of the reduced pressure distillation is preferably 90-100 ℃, and more preferably 95 ℃.

The invention provides a method for separating rare earth element yttrium from lanthanide, which comprises the following steps:

A) saponifying the extracting agent in the technical scheme by using inorganic alkali, and mixing the saponifying agent with an organic solvent to obtain a saponified extracting agent solution;

B) mixing the saponified extractant solution and the rare earth solution for extraction, so that yttrium is left in a water phase, and yttrium-depleted rare earth enters an organic phase;

the rare earth elements in the rare earth solution comprise yttrium and one or more of lanthanide series.

In the present invention, the organic solvent used in the preparation of the organic phase is preferably one or more selected from the group consisting of toluene, xylene, and sulfonated kerosene.

In the present invention, the inorganic base is preferably selected from one or more of ammonia, sodium hydroxide and potassium hydroxide; the ammonia water is preferably ammonia water solution, and the mass concentration of the ammonia water solution is preferably 20-30%, more preferably 23-27%, and most preferably 25%.

In the present invention, the amount ratio of the extractant, the organic solvent (the organic solvent in the mixture of the extractant and the organic solvent) and the inorganic base is preferably (48.4 to 81.4) g: 880mL of: (10-20) g, more preferably (55-75) g: 880mL of: (12-15) g, most preferably (60-70): 880mL of: 13.6 g.

In the invention, the lanthanide series includes one or more of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and scandium.

In the invention, the concentration of the rare earth element in the rare earth solution is preferably 0.05-1.5 mol/L, more preferably 0.1-1.2 mol/L, more preferably 0.3-1 mol/L, and most preferably 0.5-0.8 mol/L.

In the invention, the pH value of the rare earth solution is preferably 1-7, more preferably 2-6, and most preferably 3-5.

In the present invention, the preparation method of the rare earth solution preferably includes:

and dissolving the mixed rare earth oxide with hydrochloric acid to obtain a mixed rare earth solution, diluting with deionized water, and adjusting the pH value to 1-7 with hydrochloric acid.

In the present invention, the saponification degree of the saponified extractant solution is preferably 80 to 90%, more preferably 83 to 87%, and most preferably 85%.

In the invention, the volume ratio of the saponified extractant solution to the rare earth solution is preferably (55-65): (35-45), more preferably (58-62): (38-42), most preferably 60: 40.

in the present invention, the extraction is preferably performed under stirring; the extraction temperature is preferably room temperature, more preferably 20-30 ℃, and most preferably 25 ℃; the extraction time is preferably 1.5-2.5 hours, and more preferably 2 hours.

In the invention, after the yttrium-poor rare earth enters the organic phase, the organic phase is preferably washed by using an inorganic acid solution, so that the yttrium-poor rare earth enters the water phase.

In the present invention, the inorganic acid in the inorganic acid solution is preferably selected from one or more of hydrochloric acid, nitric acid and sulfuric acid.

In the invention, the concentration of the inorganic acid solution is preferably 0.5-12 mol/L, more preferably 1-10 mol/L, more preferably 3-8 mol/L, and most preferably 4-6 mol/L.

The extractant provided by the invention can effectively separate yttrium from other lanthanide elements, and compared with the naphthenic acid extractant applied in industry, the extractant has single component, is not emulsified, and has more stable extraction process; furthermore, compared with other alkyl substituted phenoxy carboxylic acid extracting agents, the 4-alkyl phenyl-4-oxobutyric acid extracting agent keeps higher separation coefficient of light rare earth elements and yttrium, improves the separation coefficient of heavy rare earth elements and yttrium, can further reduce extraction stages, shortens the process, saves economic cost and improves production efficiency.

The raw materials used in the following examples and comparative examples of the present invention are commercially available products.

In the following examples and comparative examples, the content of yttrium and other rare earths in the aqueous phase of the examples and comparative examples of the present invention was measured by using an inductively coupled plasma emission spectrometer (hereinafter referred to as ICP-OES), which is JY ULTIMA 2, manufactured by france; ICP excitation power is 1.3kW, atomizer flow is 0.75L/min, solution lifting amount is 1.50mL/min, and observation height is 1.4 cm; the analysis method refers to GB/T18114.8-2010 method for determining the proportion of fifteen rare earth element oxides in the eighth part of rare earth concentrate chemical analysis method for detection; the separation effect of yttrium and other rare earth metal ions is measured by a separation coefficient beta, and the calculation method is as follows: the concentrations of different metal ions M1 and M2 before and after extraction are respectively Ci1, Ci2, Cr1 and Cr 2; the extraction rate E of the metal ions M1 and M2 is as follows:

separation coefficient beta of metal ions M1 and M2_M1/M2Expressed as:

EXAMPLE 14 Synthesis of dimethylphenyl-4-oxobutanoic acid

a) Adding 20g of succinic anhydride and 100g of heptane into a 500mL single-mouth bottle, quickly adding 70g of anhydrous aluminum trichloride, mixing and uniformly stirring, keeping the reaction temperature at 25 ℃, and reacting for 10min to obtain a mixed solution;

b) adding 45g of dimethylbenzene into the mixed solution, continuing to react, keeping the reaction temperature at 25 ℃, and reacting for 30min to obtain a reaction solution;

c) slowly adding 200mL of deionized water into the reaction solution, stirring, standing, separating into an oil phase and a water phase, and separating out the oil phase;

d) and distilling the oil phase at 95 ℃ under reduced pressure to obtain a product, namely 4-dimethylphenyl-4-oxobutyric acid.

Through acid-base titration and nuclear magnetic resonance detection, the 4-dimethylphenyl-4-oxobutanoic acid prepared in example 1 of the present invention has the following structure:

the purity of the 4-dimethylphenyl-4-oxobutyric acid prepared in the embodiment 1 of the invention reaches 98%, and the yield reaches 95%.

EXAMPLE 24 Synthesis of dodecylphenyl-4-oxobutanoic acid

a) Adding 23g of succinic anhydride and 100g of octane into a 500mL single-mouth bottle, quickly adding 70g of anhydrous aluminum trichloride, mixing and uniformly stirring, keeping the reaction temperature at 25 ℃, and reacting for 10min to obtain a mixed solution;

b) adding 40g of dodecylbenzene into the mixed solution, continuing to react, keeping the reaction temperature at 25 ℃, and reacting for 30min to obtain a reaction solution;

c) slowly adding 400mL of deionized water into the reaction solution, stirring, standing, separating into an oil phase and a water phase, and separating out the oil phase;

d) and distilling the oil phase at 95 ℃ under reduced pressure to obtain a product, namely 4-dodecylphenyl-4-oxobutyric acid.

Through acid-base titration and nuclear magnetic resonance detection, the structure of the 4-dodecylphenyl-4-oxobutyric acid prepared in the embodiment 2 of the invention is as follows:

the purity of the 4-dodecylphenyl-4-oxobutyric acid prepared in the embodiment 2 of the invention reaches 96%, and the yield reaches 94%.

EXAMPLE 34 Synthesis of p-tert-octylphenyl-4-oxobutanoic acid

a) Adding 23g of succinic anhydride and 100g of heptane into a 500mL single-mouth bottle, quickly adding 70g of anhydrous aluminum trichloride, mixing and uniformly stirring, keeping the reaction temperature at 25 ℃, and reacting for 8min to obtain a mixed solution;

b) adding 42g of tert-octylbenzene into the mixed solution, continuing to react, keeping the reaction temperature at 25 ℃, and reacting for 30min to obtain a reaction solution;

c) slowly adding 250mL of deionized water into the reaction solution, stirring, standing, separating into an oil phase and a water phase, and separating out the oil phase;

d) and distilling the oil phase at 95 ℃ under reduced pressure to obtain a product, namely 4-p-tert-octylphenyl-4-oxobutyric acid.

Through acid-base titration and nuclear magnetic resonance detection, the structure of the 4-p-tert-octylphenyl-4-oxobutyric acid prepared in the embodiment 3 of the invention is as follows:

the purity of the 4-p-tert-octylphenyl-4-oxobutyric acid prepared in the embodiment 3 of the invention reaches 98%, and the yield reaches 96%.

EXAMPLE 44 Synthesis of di-t-butylphenyl-4-oxobutanoic acid

a) Adding 21g of succinic anhydride and 100g of octane into a 500mL single-mouth bottle, quickly adding 70g of anhydrous aluminum trichloride, mixing and uniformly stirring, keeping the reaction temperature at 25 ℃, and reacting for 15min to obtain a mixed solution;

b) adding 44g of di-tert-butyl benzene into the mixed solution, continuing to react, keeping the reaction temperature at 25 ℃, and reacting for 30min to obtain a reaction solution;

c) slowly adding 250mL of deionized water into the reaction solution, stirring, standing, separating into an oil phase and a water phase, and separating out the oil phase;

d) and distilling the oil phase at 95 ℃ under reduced pressure to obtain a product 4-di-tert-butylphenyl-4-oxobutanoic acid.

Through acid-base titration and nuclear magnetic resonance detection, the structure of the 4-di-tert-butylphenyl-4-oxobutanoic acid prepared in embodiment 4 of the present invention is:

the purity of the 4-di-tert-butylphenyl-4-oxobutanoic acid prepared in example 4 of the present invention reaches 95%, and the yield reaches 94%.

Example 5 separation of rare earths

The steps for separating the rare earth element yttrium from the lanthanide series are as follows:

A) preparing a rare earth solution: and dissolving the mixed rare earth oxide with hydrochloric acid to obtain a mixed rare earth solution, diluting the mixed rare earth solution with deionized water, and adjusting the pH value with hydrochloric acid, wherein the total concentration of the rare earth solution is 0.132mol/L, and the pH value is 5, and the concentrations of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium are all 0.0088 mol/L.

B)48.4g of 4-dimethylphenyl-4-oxobutanoic acid prepared in example 1 was saponified with 13.6g of a commercially available aqueous ammonia solution having a mass concentration of 25 wt.% (degree of saponification: 85%, ratio of carboxylic acid reacted with aqueous ammonia to all carboxylic acids) and mixed with 880.0mL of toluene to give a saponified extractant solution having a concentration of 0.267 mol/L.

C) Mixing 60mL of saponified extractant solution with 40mL of the rare earth solution at room temperature, extracting for 2h (single-stage extraction), testing the concentration of rare earth ions in the aqueous phase before and after extraction, and calculating the relative separation coefficient beta of each rare earth ion (Ln) relative to yttrium ion (Y)_Ln/YThe test results are shown in table 1.

Example 6

Rare earth was separated as described in example 5, except that 81.4g of 4-dodecylphenyl-4-oxobutanoic acid prepared in example 2 was saponified with 13.6g of a commercially available aqueous ammonia solution having a mass concentration of 25 wt.% (degree of saponification: 85%) and then mixed with 880.0mL of sulfonated kerosene to give an extractant solution having a concentration of 0.267 mol/L.

The detection was carried out in accordance with the method of example 5, and the concentrations of the rare earth ions in the aqueous phase before and after the extraction were measured, and the relative separation coefficient β of each rare earth ion (Ln) with respect to the yttrium ion (Y) was calculated_Ln/YThe test results are shown in table 1.

Example 7

Rare earth was separated as described in example 5, except that 68.1g of 4-p-tert-octylphenyl-4-oxobutanoic acid prepared in example 3 was saponified with 40g of a 20 wt.% sodium hydroxide solution (degree of saponification: 85%) and mixed with 880.0mL of xylene to give an extractant solution having a concentration of 0.267 mol/L.

The detection was carried out in accordance with the method of example 5, and the concentrations of the rare earth ions in the aqueous phase before and after the extraction were measured, and the relative separation coefficient of each rare earth ion (Ln) with respect to the yttrium ion (Y) was calculatedβ_Ln/YThe test results are shown in table 1.

Example 8

Rare earth was separated as described in example 5, except that 68.1g of 4-di-tert-butylphenyl-4-oxobutanoic acid prepared in example 4 was saponified with 40g of a 20 wt.% sodium hydroxide solution (degree of saponification: 85%) and mixed with 880.0mL of xylene to give an extractant solution having a concentration of 0.267 mol/L.

The detection was carried out in accordance with the method of example 5, and the concentrations of the rare earth ions in the aqueous phase before and after the extraction were measured, and the relative separation coefficient β of each rare earth ion (Ln) with respect to the yttrium ion (Y) was calculated_Ln/YThe test results are shown in table 1.

Example 9

Rare earth was separated as described in example 5, except that a mixture of 4-p-tert-octylphenyl-4-oxobutanoic acid prepared in example 3 and 4-di-tert-butylphenyl-4-oxobutanoic acid prepared in example 4 was used as an extractant in a molar ratio of 10:1, and the total mass of the extractants was 68.2g (62 g of 4-p-tert-octylphenyl-4-oxobutanoic acid, 6.2g of 4-di-tert-butylphenyl-4-oxobutanoic acid), and 40g of a 20 wt.% sodium hydroxide solution was saponified and then mixed with 880.0mL of xylene after saponification (degree of saponification: 85%) to obtain an extractant solution having a concentration of 0.267 mol/L.

The detection was carried out in accordance with the method of example 5, and the concentrations of the rare earth ions in the aqueous phase before and after the extraction were measured, and the relative separation coefficient β of each rare earth ion (Ln) with respect to the yttrium ion (Y) was calculated_Ln/YThe test results are shown in table 1.

Comparative example 1

Rare earth was separated according to the method described in example 5, which is different from example 5 in that 40.0g of a naphthenic acid extractant for industrial use (naphthenic acid product provided by tombarthite, ltd.) was saponified with aqueous ammonia (degree of saponification: 85%) and mixed with 880.0mL of toluene to obtain an extractant solution having a concentration of 0.267 mol/L.

The assay was carried out as described in example 5, and the assay results are shown in Table 1.

TABLE 1 separation coefficient beta of each rare earth ion from yttrium ion in inventive example and comparative example_Ln/Y

As can be seen from Table 1, the separating coefficient beta of the extractant prepared in the example of the present invention for other rare earth ions (Ln) and yttrium ions (Y)_Ln/YThe extraction agent prepared by the embodiment of the invention is a potential extraction agent capable of replacing naphthenic acid, and has a good application prospect. In addition, from example 9, when the extracting agent contains both the compound having the structure of formula (I) and the compound having the structure of formula (II), the extracting effect is better than that when the extracting agent contains only the compound having the structure of formula (I) or only the compound having the structure of formula (II).

While only the preferred embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.