CN107287456A - A kind of extracting process of separating-purifying heavy rare earth - Google Patents

Abstract

An extraction method for separating and purifying heavy rare earths, the method uses an organic relative sulfuric acid rare earth solution containing an extractant and a diluent for extraction; the extractant is an ether amide functional ionic liquid. The method adopts water as a back-extraction liquid to back-extract the rare earth elements extracted into the n-heptane to obtain a rare-earth-containing back-extraction liquid to realize the extraction and separation of the rare earth elements. In the present invention, because the ether oxygen bond in the ether amide functional ionic liquid structure improves its solubility in diluents and its affinity to rare earth ions, its separation ability between rare earth elements has been significantly improved, especially In the extraction process, the heavy rare earth elements are preferentially extracted, and there is no need for iron and aluminum pretreatment, and in the subsequent stripping process, the heavy rare earth stripping can usually be achieved with only water, reducing the consumption of acid and alkali. The present invention has good interface phenomenon in the extraction process, and the extraction and separation effect can be achieved without saponification of the extraction agent and without addition of a salting-out agent.

Description

An extraction method for separating and purifying heavy rare earth

technical field

The invention relates to an extraction method for separating and purifying heavy rare earths, belonging to the technical field of rare earth extraction.

Background technique

Rare earths have excellent optical, electrical and magnetic properties, and are widely used in the fields of national defense and military industry and high-tech new materials, and have the reputation of "industrial vitamins". Among them, the distribution of medium and heavy rare earths (samarium to lutetium and yttrium) in southern ion-adsorption rare earth mines is as high as 30% to 80%. Close, the product has high added value, and its irreplaceable important application in the fields of high-tech and national defense and military industry really restricts the development of related foreign fields, and it is a strategic resource with absolute competitive advantages.

At present, the separation of single rare earth mainly adopts the extraction and separation method of P507 (2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester) as the extractant. However, the separation of heavy rare earths in the P507 extraction system still has the problems of high acidity in stripping, incomplete stripping, and large acid-base consumption, which affects the separation and high purification of heavy rare earths. In addition, with the gradual improvement of national environmental protection requirements, the existing P507 extraction system has increasingly prominent problems such as large acid-base consumption and ammonia nitrogen pollution. From the perspective of source prevention, the development of new extraction agents with low acid-base consumption and high selectivity and The extraction system is crucial to the development of a new process for the efficient and clean separation of rare earths.

In recent years, functional ionic liquids have been widely concerned in the field of rare earth separation as a research hotspot in green chemistry. The prior art discloses a variety of methods for separating rare earths with functional ionic liquids as extraction agents. Publication No. CN101723975 discloses "A A kind of preparation method of quaternary ammonium bifunctional ionic liquid "This method adopts the neutralization reaction between quaternary ammonium base and organic phosphine (carboxylic) acid extractant to eliminate hydrogen ions on the extractant, and realizes non-saponification extraction. The prepared acid-base coupling type bifunctional ionic liquid extractant (code-named ABC-BIL) can effectively avoid the pollution caused by the saponification wastewater produced by the application of the phosphine (carboxylic) acid extractant; the publication number CN102618736 discloses a " "Extraction and Separation Method of Rare Earth Elements", using the above-mentioned ionic liquid to extract and separate rare earth elements; however, the functional ionic liquid generally used in the prior art has relatively weak ability to extract and separate trivalent rare earth elements in a sulfuric acid medium , especially the low removal rate of divalent metals such as iron, aluminum and zinc, which makes it difficult to obtain high-purity heavy rare earth products.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the prior art, and to provide an extraction method for separating and purifying heavy rare earths. The etheramide functional ionic liquid used does not need saponification, and has strong extraction ability for rare earth elements in sulfuric acid medium and is easy to reverse extract.

The technical solution for realizing the present invention is an extraction method for separating and purifying heavy rare earths, the method extracts with an organic relative sulfuric acid rare earth solution containing an extractant and a diluent; the extractant is an ether amide functional ionic liquid; the The method uses water as the stripping solution to strip the rare earth elements extracted into the n-heptane to obtain a stripping solution containing rare earths, so as to realize the extraction and separation of the rare earth elements.

The ether amide functional ionic liquid has the following general structural formula:

Wherein, R1 and R2 are independent straight-chain or branched-chain alkyl groups, at least one of which is an alkyl group with at least 4 carbon atoms, R3 is a straight-chain alkyl group with 2 to 8 carbon atoms, and X is chlorine One of anion, bromide anion, hexafluorophosphate, bis(trifluoroalkylsulfonyl)amide anion.

The preparation method steps of the ether amide functional ionic liquid are:

(1) Diglycolic anhydride and dialkylamine are reacted in THF to generate corresponding dialkyl diglycol amic acid with a molar ratio of 1.1:1;

(2) carry out amide reaction with dialkyl diglycol amic acid and 1-(3-aminopropyl) imidazole, dicyclohexyl carbodiimide, 1-hydroxybenzotriazole in organic reagent, pass through filtration, Washing, silica gel column chromatography separation steps to obtain ether amide functionalized imidazole;

(3) reacting the etheramide functionalized imidazole with the halide to generate the etheramide functional ionic liquid in which the anion is a halogen ion;

(4) Carry out anion exchange reaction with the ether amide functional ionic liquid whose anion is a halogen and the inorganic salt in the presence of an organic reagent, and then remove the inorganic salt and the organic reagent by filtering, washing, and vacuum distillation steps to obtain the corresponding ether amide function Sexual ionic liquids.

The mol ratio of described dialkyl diglycol amic acid and 1-(3-aminopropyl) imidazole, dicyclohexylcarbodiimide, 1-hydroxybenzotriazole reaction is 1.2:1:1.2:1.2, The reaction takes chloroform as a solvent, and the reaction is carried out under the protection of an inert gas;

The molar ratio of the ether amide functionalized imidazole to the alkyl halide reaction is 1:1.2, and the reaction takes acetonitrile as a solvent, and the reaction is carried out under the protection of an inert gas;

The molar ratio of the reaction between the ether amide functional ionic liquid whose anion is a halogen and the inorganic salt is 1:2.5, and the reaction uses acetonitrile as a solvent.

The concentration of the n-heptane solution of the ether amide functional ionic liquid is 0.01-0.1 mol/L.

The concentration of the rare earth sulfate solution is 0.2-3 mmol/L.

The rare earth includes one or more of Eu3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+, Y3+.

The beneficial effect of the present invention is that, in the present invention, since the ether oxygen bond in the ether amide functional ionic liquid structure improves its solubility in the diluent and the affinity to rare earth ions, making it resistant to rare earth elements The separation ability between them has been significantly improved, especially in the extraction process, heavy rare earth elements are preferentially extracted, no pre-treatment for iron and aluminum removal is required, and in the subsequent stripping process, heavy rare earth stripping can usually be achieved with only water, Reduced acid-base consumption. In addition, the method of the present invention has good interfacial phenomena during the extraction process, and the extraction and separation effect can be achieved without saponification of the extraction agent or addition of a salting-out agent.

Description of drawings

Fig. 1 is the structural formula figure of ether amide functional ionic liquid of the present invention;

Figure 2 is a dot diagram of [DGA][PF6] as the extractant when the solution equilibrium pH value and the extraction distribution ratio of rare earth ions;

Figure 3 is a dot diagram of the equilibrium pH value of the solution and the extraction distribution ratio of rare earth ions when [D2EHGA][PF6] is used as the extractant.

detailed description

Example 1

Weigh 100g of diglycolic anhydride and dissolve it in 1000mL of tetrahydrofuran, add 189g of di-n-octylamine, and react at room temperature for 48 hours under the protection of argon, and dissolve the obtained solution in 400mL of chloroform after rotary evaporation, and wash with dilute hydrochloric acid solution After distillation and vacuum drying, dioctyl diglycol amic acid was obtained; 90g dioctyl diglycol amic acid, 37.2g aminopropyl imidazole, 61.2g dicyclohexylcarbodiimide, 40.2g 1-hydroxybenzene Dissolve triazole in 1000mL chloroform, react at room temperature under the protection of argon for 12h, filter the solution under reduced pressure, distill and dissolve it in 500mL ethyl acetate, wash with sodium carbonate solution to remove residual 1-hydroxybenzo Triazole, spin out ethyl acetate under vacuum condition, adopt silica gel column chromatography, use chloroform and methanol as mobile phase, obtain 2-[2-(aminopropyl imidazole-2 oxo)]-N,N -dioctylacetamide; Weigh 102g 2-[2-(aminopropylimidazole-2 oxo)]-N,N-dioctylacetamide, 37.14g bromobutane is dissolved in 1000mL acetonitrile, at 80 Stir the reaction at ℃ for 48 hours, wash with n-hexane to remove excess bromobutane, and remove acetonitrile by rotary evaporation to obtain ether amide functionalized imidazolium bromide salt; Mix the acetonitrile solution of lithium trifluoromethanesulfonyl imide, react at room temperature for 24h, wash with water to remove the residual lithium bistrifluoromethanesulfonimide, spin distill acetonitrile and water under vacuum conditions to obtain bistrifluoromethanesulfonyl The ether amide functional ionic liquid whose imide root is an anion is marked as [DGA-TSIL][Tf2N].

Example 2

Weigh 100g of diglycolic anhydride and dissolve in 1000mL of tetrahydrofuran, add 189g of di(2-ethylhexyl)amine, and react at room temperature for 48h under the protection of argon, and dissolve the obtained solution in 400mL of chloroform after rotary evaporation, and use After washing with dilute hydrochloric acid solution, distill and vacuum-dry to obtain bis(2-ethylhexyl) diglycol amic acid; 90g bis(2-ethylhexyl) diglycol amic acid, 37.2g aminopropyl imidazole, 61.2 g of dicyclohexylcarbodiimide and 40.2g of 1-hydroxybenzotriazole were dissolved in 1000mL of chloroform, reacted at room temperature under the protection of argon for 12h, and the solution was filtered under reduced pressure, distilled and dissolved in 500mL of ethyl acetate In, wash with sodium carbonate solution to remove residual 1-hydroxybenzotriazole, spin out ethyl acetate under vacuum condition, adopt silica gel column chromatography, use trichloromethane and methanol as mobile phase, obtain 2-[2- (Aminopropylimidazole-2oxo)]-N,N-di(2-ethylhexyl)acetamide; Weigh 102g 2-[2-(aminopropylimidazole-2oxo)]-N,N -Bis(2-ethylhexyl)acetamide, 37.14g bromobutane dissolved in 1000mL acetonitrile, stirred and reacted at 80°C for 48h, washed with n-hexane to remove excess bromobutane, and rotary evaporated to remove acetonitrile to obtain ether amide functionalized imidazolium bromide salt; 71g ether amide functionalized imidazolium bromide salt was dissolved in 600mL acetonitrile, mixed with 50.12g sodium hexafluorophosphate in acetonitrile solution, reacted at room temperature for 24h, washed with water to remove residual sodium hexafluorophosphate, vacuum Acetonitrile and water were evaporated under the conditions to obtain an etheramide-based functional ionic liquid with hexafluorophosphate as an anion, which was marked as [D2EHGA-TSIL][PF6].

Example 3

Weigh 100g of diglycolic anhydride and dissolve it in 1000mL of tetrahydrofuran, add 189g of di-n-octylamine, and react at room temperature for 48 hours under the protection of argon, and dissolve the obtained solution in 400mL of chloroform after rotary evaporation, and wash with dilute hydrochloric acid solution After distillation and vacuum drying, dioctyl diglycol amic acid was obtained; 90g dioctyl diglycol amic acid, 37.2g aminopropyl imidazole, 61.2g dicyclohexylcarbodiimide, 40.2g 1-hydroxybenzene Dissolve triazole in 1000mL chloroform, react at room temperature under the protection of argon for 12h, filter the solution under reduced pressure, distill and dissolve it in 500mL ethyl acetate, wash with sodium carbonate solution to remove residual 1-hydroxybenzo Triazole, spin out ethyl acetate under vacuum condition, adopt silica gel column chromatography, use chloroform and methanol as mobile phase, obtain 2-[2-(aminopropyl imidazole-2 oxo)]-N,N - Dioctyl acetamide; Weigh 102g 2-[2-(aminopropylimidazole-2 oxo)]-N,N-dioctyl acetamide, 37.14g chlorobutane is dissolved in 1000mL acetonitrile, at 90 Stir the reaction at ℃ for 48 hours, wash with n-hexane to remove excess chlorobutane, and remove acetonitrile by rotary evaporation to obtain ether amide functionalized imidazolium chloride salt; dissolve 65.87 g of ether amide functionalized imidazolium chloride salt in 600 mL of acetonitrile, and Mix sodium hexafluorophosphate and acetonitrile solution, react at room temperature for 24 hours, wash with water to remove residual sodium hexafluorophosphate, spin out acetonitrile and water under vacuum conditions, and obtain etheramide functional ionic liquid with hexafluorophosphate as anion , marked as [DGA-TSIL][PF6].

Example 4

Weigh 100g of diglycolic anhydride and dissolve in 1000mL of tetrahydrofuran, add 189g of di(2-ethylhexyl)amine, and react at room temperature for 48h under the protection of argon, and dissolve the obtained solution in 400mL of chloroform after rotary evaporation, and use After washing with dilute hydrochloric acid solution, distill and vacuum-dry to obtain bis(2-ethylhexyl) diglycol amic acid; 90g of bis(2-ethylhexyl) diglycol amic acid, 37.2g aminopropyl imidazole, 61.2 g of dicyclohexylcarbodiimide and 40.2g of 1-hydroxybenzotriazole were dissolved in 1000mL of chloroform, reacted at room temperature under the protection of argon for 12h, and the solution was filtered under reduced pressure, distilled and dissolved in 500mL of ethyl acetate In, wash with sodium carbonate solution to remove residual 1-hydroxybenzotriazole, spin out ethyl acetate under vacuum condition, adopt silica gel column chromatography, use chloroform and methanol as mobile phase, obtain 2-[2- (Aminopropylimidazole-2oxo)]-N,N-di(2-ethylhexyl)acetamide; Weigh 102g 2-[2-(aminopropylimidazole-2oxo)]-N,N -Bis(2-ethylhexyl)acetamide, 37.14g chlorobutane dissolved in 1000mL acetonitrile, stirred and reacted at 85°C for 48h, washed with n-hexane to remove excess chlorobutane, and rotary evaporated to remove acetonitrile to obtain ether amide functionalized imidazolium bromide salt; 65.87g ether amide functionalized imidazolium chloride salt was dissolved in 600mL acetonitrile, mixed with 85.2g acetonitrile solution of lithium bistrifluoromethanesulfonylimide, reacted at room temperature for 24h, washed with water to remove residual Lithium bistrifluoromethanesulfonylimide, acetonitrile and water were evaporated under vacuum conditions to obtain an etheramide-based functional ionic liquid with bistrifluoromethanesulfonylimide as an anion, marked as [D2EHGA-TSIL][Tf2N ].

Embodiment 5-8

Embodiment 5 adopts Eu3+ as the rare earth ion, Y3+ as the rare earth ion in Embodiment 6, Yb3+ as the rare earth ion in Embodiment 7, and Lu3+ as the rare earth ion in Embodiment 8 to prepare rare earth solutions respectively.

Using 0.05mol/L [DGA-TSIL][PF6]n-heptane solution as the extraction organic phase, prepare the rare earth solution with the concentration of rare earth ions at 5.0×10-4mol/L and the concentration of sulfuric acid at 0.2mol/L. They are Eu3+, Y3+, Yb3+ and Lu3+ respectively. Mix the organic phase with a volume ratio of 1:1 and the rare earth solution, shake and extract at room temperature for 15 minutes, and the extraction order is 1. After the extraction, the concentration of rare earth ions in the water phase was measured, and the distribution ratios of Eu3+, Y3+, Yb3+ and Lu3+ were calculated to be 5.59, 25.29, 6.85 and 9.26, respectively.

Examples 9-12

The rare earth solutions were prepared by using Eu3+ as the rare earth ion in Example 9, Y3+ as the rare earth ion in Example 10, Yb3+ as the rare earth ion in Example 11, and Lu3+ as the rare earth ion in Example 12.

With 0.05mol/L [D2EHGA-TSIL][PF6]n-heptane solution as the extraction organic phase, prepare rare earth ion concentration of 5.0×10-4mol/L, sulfuric acid concentration of 0.2mol/L rare earth solution, rare earth ion They are Eu3+, Y3+, Yb3+ and Lu3+ respectively. Mix the organic phase with a volume ratio of 1:1 and the rare earth solution, shake and extract at room temperature for 15 minutes, and the extraction order is 1. After the extraction, the concentration of rare earth ions in the water phase was measured, and the distribution ratios of Eu3+, Y3+, Yb3+ and Lu3+ were calculated to be 1.22, 7.09, 3.28 and 5.16, respectively.

Examples 13-16

In Example 13, the rare earth ion is Eu3+, in Example 14, the rare earth ion is Y3+, in Example 15, the rare earth ion is Yb3+, and in Example 16, the rare earth ion is Lu3+ to prepare rare earth solutions.

With 0.05mol/L [DGA-TSIL][Tf2N] n-heptane solution as the extraction organic phase, the rare earth ion concentration is 5.0×10-4mol/L, the concentration of sulfuric acid is 0.2mol/L rare earth solution, the rare earth ion They are Eu3+, Y3+, Yb3+ and Lu3+ respectively. Mix the organic phase with a volume ratio of 1:1 and the rare earth solution, shake and extract at room temperature for 15 minutes, and the extraction order is 1. After the extraction, the concentration of rare earth ions in the water phase was measured, and the distribution ratios of Eu3+, Y3+, Yb3+ and Lu3+ were calculated to be 2.75, 12.26, 5.22 and 6.38, respectively.

Examples 17-20

Example 17 uses Eu3+ as the rare earth ion, Example 18 uses Y3+ as the rare earth ion, Example 19 uses Yb3+ as the rare earth ion, and Example 20 uses Lu3+ as the rare earth ion to prepare rare earth solutions respectively.

Using 0.05mol/L [D2EHGA-TSIL][Tf2N]n-heptane solution as the extraction organic phase, prepare rare earth ion concentration of 5.0×10-4mol/L, sulfuric acid concentration of 0.2mol/L rare earth solution, rare earth ion They are Eu3+, Y3+, Yb3+ and Lu3+ respectively. Mix the organic phase with a volume ratio of 1:1 and the rare earth solution, shake and extract at room temperature for 15 minutes, and the extraction order is 1. After the extraction, the concentration of rare earth ions in the water phase was measured, and the distribution ratios of Eu3+, Y3+, Yb3+ and Lu3+ were calculated to be 1.50, 4.54, 2.71 and 3.95, respectively.

Example 21

Effect of solution equilibrium pH value on distribution ratio of single rare earth ion extracted by [DGA-TSIL][PF6]:

0.05mol/L [DGA-TSIL][PF6]n-heptane solution was used as the extraction organic phase, and the concentration of rare earth ions was prepared to be 5.0×10-4mol/L, and the rare earth ions were Lu3+, Y3+, and Eu3+ respectively. Mix the organic phase with a volume ratio of 1:1 and the rare earth solution, shake and extract at room temperature for 15 minutes, and the extraction order is 1. After the extraction is completed, the equilibrium pH value of the water phase and the concentration of rare earth ions in the corresponding water phase are measured respectively, and the extraction distribution ratio of the rare earth ions is calculated. Figure 2 is a dot diagram of the solution equilibrium pH value and rare earth extraction distribution ratio when [DGA-TSIL][PF6] is the extractant. It can be seen from the figure that at higher acidity, the distribution ratio of rare earth ions increases with the equilibrium The pH value increases and decreases, and at lower acidity, when the equilibrium pH value increases, the distribution ratio of rare earth ions increases.

Example 22

The effect of solution equilibrium pH value on the distribution ratio of single rare earth ion extracted by [D2EHGA-TSIL][PF6]:

0.05mol/L [D2EHGA-TSIL][PF6] n-heptane solution was used as the extraction organic phase, and the concentration of rare earth ions was prepared to be 5.0×10-4mol/L, and the rare earth ions were Lu3+, Y3+, Eu3+ respectively. Mix the organic phase with a volume ratio of 1:1 and the rare earth solution, shake and extract at room temperature for 15 minutes, and the extraction order is 1. After the extraction is completed, the equilibrium pH value of the water phase and the concentration of rare earth ions in the corresponding water phase are measured respectively, and the extraction distribution ratio of the rare earth ions is calculated. Figure 3 is a point diagram of the equilibrium pH value of the solution and the distribution ratio of rare earth extraction when [D2EHGA-TSIL][PF6] is the extractant. It can be seen from the figure that at higher acidity, when the equilibrium pH value increases, The distribution ratio of rare earth ions decreases, and at lower acidity, the distribution ratio of rare earth ions increases with the increase of equilibrium pH.

Example 23

Take the 0.10mol/L [DGA-TSIL][PF6]n-heptane solution as the organic phase for extraction, take the mixed aqueous solution, the total concentration of metal ions is 3.5×10-3mol/L, and the mixed solution of sulfuric acid concentration is 0.2mol/L , wherein the metal ions are Eu3+, Y3+, Yb3+, Lu3+, Fe3+, Al3+, Zn2+ respectively, and the concentration is 5.0×10-4mol/L. The organic phase and the mixed solution with a volume ratio of 1:1 were shaken and extracted at room temperature for 15 minutes, and the extraction order was 1. After the extraction was completed, measure the concentration of metal ions in the aqueous phase, and calculate the extraction rates of Eu3+, Y3+, Yb3+, Lu3+ to be 87.52%, 97.34%, 88.95%, 91.92% respectively, while Al3+ and Zn2+ were not extracted, and the extraction rates of Fe3+< 5%, the results show that under high acidity conditions, [DGA-TSIL][PF6] preferentially extracts rare earth elements, and almost does not extract impurity elements such as iron, aluminum, and zinc.

Example 24

Take 0.10mol/L of [D2EHGA-TSIL][PF6]n-heptane solution as the extraction organic phase, take the mixed aqueous solution, the total concentration of metal ions is 3.5×10-3mol/L, and the mixed solution of sulfuric acid concentration is 0.2mol/L , wherein the metal ions are Eu3+, Y3+, Yb3+, Lu3+, Fe3+, Al3+, Zn2+ respectively, and the concentration is 5.0×10-4mol/L. Mix the organic phase with a volume ratio of 1:1 and the rare earth sulfate solution, shake and extract at room temperature for 15 minutes, and the extraction order is 1. After the extraction was completed, the concentration of metal ions in the water phase was measured, and the extraction rates of Eu3+, Y3+, Yb3+, and Lu3+ were calculated to be 74.02%, 83.72%, 77.58%, and 80.16% respectively, while Fe3+, Al3+ and Zn2+ were not extracted. The results showed that in Under high acidity conditions, [D2EHGA-TSIL][PF6] preferentially extracts rare earth elements, and does not extract impurity elements such as iron, aluminum, and zinc.

The above descriptions are only preferred embodiments of the present invention, and it should be pointed out that various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented without departing from the present invention. It is implemented in other embodiments without departing from its spirit or scope. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. a kind of extracting process of separating-purifying heavy rare earth, it is characterised in that methods described is with comprising extractant and diluent Organic phase is extracted to rare earth sulfate solution；The extractant is ether amide functional ionic liquids；Methods described uses water As strip liquor, the rare earth element being extracted in normal heptane is stripped, the anti-stripping agent containing rare earth is obtained, realizes rare earth The extraction separation of element.

2. a kind of extracting process of separating-purifying heavy rare earth according to claim 1, it is characterised in that the ether amide work( Energy property ionic liquid has following general structure：

Wherein, R1 and R2 is each independent straight or branched alkyl, and at least one is the alkyl base with least four carbon atom Group, R3 is the straight chained alkyl that carbon number is 2~8, and X is chlorine anion, bromine anion, hexafluoro-phosphate radical, double (trifluoroalkyl sulphurs Acyl group) one kind in amido anion.

3. a kind of extracting process of separating-purifying heavy rare earth according to claim 2, it is characterised in that the ether amide work( Can the preparation method step of property ionic liquid be：

(1) it is 1.1 by mol ratio:1 anhydride diethylene glycol and dialkylamine reacts the corresponding dialkyl group of generation in tetrahydrofuran Diethylene glycol (DEG) amic acid；

(2) by dialkyl group diethylene glycol (DEG) amic acid and 1- (3- aminopropyls) imidazoles, dicyclohexylcarbodiimide, 1- hydroxy benzos three Azoles carries out acid amides reaction in organic reagent, and ether amide functionalization miaow is obtained by filtering, washing, silica gel column chromatography separating step Azoles；

(3) ether amide functionalization imidazoles and halide are reacted into the ether amide functional ion liquid that generation anion is halide ion Body；

(4) by anion for ether amide functional ionic liquids and the inorganic salts of halogen is carried out in the presence of organic reagent the moon from Sub- exchange reaction, then corresponding ether amide work(is obtained by filtering, washing, vacuum distillation step removing inorganic salts and organic reagent Can property ionic liquid.

4. a kind of extracting process of separating-purifying heavy rare earth according to claim 3, it is characterised in that the dialkyl group two Glycol amic acid and the mol ratio of 1- (3- aminopropyls) imidazoles, dicyclohexylcarbodiimide, I-hydroxybenzotriazole reaction are 1.2:1:1.2:1.2, react using chloroform as solvent, reaction is carried out under inert gas shielding；

The ether amide functionalization imidazoles is 1 with alkyl halide reaction mol ratio:1.2, react using acetonitrile as solvent, react in inertia Carried out under gas shield；

The anion is the ether amide functional ionic liquids of halogen and the mol ratio of inorganic salt reaction is 1:2.5, reaction with Acetonitrile is solvent.

5. a kind of extracting process of separating-purifying heavy rare earth according to claim 2, the ether amide functional ion liquid The concentration of the n-heptane solution of body is 0.01~0.1mol/L.

6. a kind of extracting process of separating-purifying heavy rare earth according to claim 1, it is characterised in that the sulfuric acid rare earth The concentration of solution is 0.2~3mmol/L.

7. the extracting process of a kind of separating-purifying heavy rare earth according to claim 1, it is characterised in that the rare earth includes Eu3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+, Y3+ one or more.