Construction of green extraction system and application of green extraction system in rhenium extraction

Abstract

The invention relates to the technical field of hydrometallurgy, and discloses construction of a green extraction system and application of the green extraction system in rhenium extraction. According to the specific scheme, the method comprises the following steps: synthesizing a plurality of functionalized ionic liquids, respectively preparing organic phases with a diluent according to a certain proportion by taking the functionalized ionic liquids as extraction agents, and forming a multi-element green extraction system by the organic phases and a water phase according to a set phase ratio; and rhenium is extracted under certain experimental conditions. The method is good in rhenium selectivity, the extraction rate can reach 99% or above, and compared with a traditional extraction mode, the adopted multi-element green extraction system is more environmentally friendly, higher in efficiency and beneficial to industrial development of rhenium extraction.

Description

Technical Field

[0001] The invention belongs to the field of hydrometallurgy, and in particular relates to the construction of a green extraction system and the application of the system in extracting rhenium. Background Art

[0002] Rhenium is a very valuable metal in industry. It has excellent ductility, formability, high temperature resistance, high strength and high resistance. It is widely used in cutting-edge scientific and technological fields such as national defense, aerospace, petrochemical, nuclear energy, thermal component manufacturing, electronics industry, high energy physics, etc. Among the abundant rare metals in my country, only rhenium has the smallest reserves, so it is urgent to explore more effective rhenium extraction processes.

[0003] At present, the main channel for recovering and extracting rhenium is the by-product of smelting molybdenum ore and copper ore. With the development of analytical science, many methods for separating and enriching rhenium have also emerged. For example, solvent extraction, liquid membrane separation, ion exchange, and so on. Liquid membrane separation has the characteristics of low energy consumption, high selectivity, high enrichment multiples, and simple and fast operation, but the application of this method is still in its early stages of development and there are still certain technical immaturity issues. In comparison, the ion exchange method has the advantages of high efficiency, low environmental pollution, and resin regeneration, but the operation process is complicated and time-consuming, and the sample is susceptible to contamination and damage.

[0004] Solvent extraction utilizes the different solubility of heavy metal ions in the organic phase or the aqueous phase, allowing them to enter the organic phase from the aqueous phase, thereby achieving the separation effect. Therefore, solvent extraction is the most effective technical means in industrial production. Amines are currently widely used as extractants for rare elements, with TOA and N235 being typical representatives. They have a high extraction rate for metal anions, and the extraction of rhenium is achieved through solvation reactions and anion exchange reactions. However, such extractants are highly toxic and volatile, and the extraction is mostly carried out in acidic or very weak alkaline media. Therefore, it is urgent to explore a green extraction system suitable for industrial production. Summary of the invention

[0005] The widely used rhenium extraction methods at present still have many shortcomings. The present invention provides a green extraction system. The system has good selectivity for rhenium and the extraction rate can be as high as 99% or more. The multi-element extraction system adopted is greener and more efficient than the traditional extraction method, and has good application prospects.

[0006] The technical solution for constructing a green extraction system and its application in extracting rhenium is: a method for constructing a green extraction system, and the construction method is as follows: synthesize a variety of functionalized ionic liquids, and then use them as extractants and diluents to prepare organic phases in a certain proportion, and the organic phase and the aqueous phase are compared according to the set ratio to form a multi-element green extraction system.

[0007] In the above-mentioned method for constructing a green extraction system, a plurality of functionalized ionic liquids are prepared by tetrabutylammonium chloride and di(2-ethylhexyl) phosphate, 2-ethylhexyl phosphate mono-2-ethylhexyl ester, and bis(2,4,4-trimethylpentyl)phosphonic acid, respectively. 4444 ][DEHP]、[N 4444 ][EHEHP]、[N 4444 ][BTMPP].

[0008] The above-mentioned method for constructing a green extraction system, the preparation method of multiple functionalized ionic liquids is as follows: 5 parts of di(2-ethylhexyl) phosphate, 2-ethylhexyl phosphate mono-2-ethylhexyl ester or di(2,4,4-trimethylpentyl)phosphonic acid are uniformly stirred with 100 parts of anhydrous ethanol, the pH is adjusted with sodium hydroxide solution, the ethanol is evaporated to remove, more than 5 parts of tetrabutylammonium chloride are added thereto, 100 parts of dichloromethane are added after stirring at room temperature for 48 hours, stirring is continued, the aqueous phase is separated, the organic phase is washed with deionized water, and finally rotary evaporation and vacuum drying are performed to remove dichloromethane and water to obtain a viscous ionic liquid [N 4444 ][DEHP]. [N 4444 ][EHEHP] and [N 4444 ][BTMPP]The synthesis method is the same as above.

[0009] The above-mentioned method for constructing a green extraction system, in which the diluent is 1-alkyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt [C n mim][NTf2] (n = 2 to 8) or 1-alkyl-3-methylimidazolium hexafluorophosphate [C n mim][PF6](n=2~8).

[0010] In the above-mentioned method for constructing a green extraction system, the aqueous phase is rhenium-containing wastewater in smelting production.

[0011] The above-mentioned method for constructing a green extraction system has a volume ratio of extractant: diluent = 1-10:30-100.

[0012] In the above-mentioned method for constructing a green extraction system, the volume ratio of the organic phase to the aqueous phase is 1:1.

[0013] The application of the green extraction system constructed by the above-mentioned construction method in the extraction of rhenium.

[0014] The above application method is as follows: use the above extraction system to extract rhenium, the extraction temperature is 20-60°C, stirring for 10-40 minutes, standing and stratifying to collect the rhenium-containing organic phase, and post-processing to obtain the rhenium product.

[0015] The beneficial effects of the present invention are:

[0016] The green multi-element extraction system used in the present invention can effectively replace the current traditional extraction system, making up for the high pollution, high cost and low extraction efficiency of the traditional system. The experimental conditions have good selectivity for rhenium and the extraction rate can be as high as 99% or more, which has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 For the ionic liquid of Example 1 [N 4444 ][DEHP] H NMR spectrum.

[0018] Figure 2 For the ionic liquid of Example 1 [N 4444 ][DEHP]NMR carbon spectrum.

[0019] Figure 3 For the ionic liquid of Example 2 [N 4444 ][EHEHP]NMR hydrogen spectrum.

[0020] Figure 4 For the ionic liquid of Example 2 [N 4444 ][EHEHP]NMR carbon spectrum.

[0021] Figure 5 For the ionic liquid of Example 3 [N 4444 ][BTMPP] H NMR spectrum.

[0022] Figure 6 For the ionic liquid of Example 3 [N 4444 ][BTMPP]NMR carbon spectrum. DETAILED DESCRIPTION

[0023] The following specific examples are provided to further illustrate the present invention, but they should not be construed as limitations of the present invention. Without departing from the spirit and substance of the present invention, any modification or replacement of the methods, steps or conditions of the present invention should be included in the scope of the claims of the present invention.

[0024] Example 1

[0025] 1) Functionalized ionic liquids [N 4444 Synthesis of ][DEHP]

[0026] Dissolve 5 parts of di(2-ethylhexyl) phosphate in 100 parts of anhydrous ethanol according to mass fractions, and use 1 mol·L -1 The NaOH solution was adjusted to neutrality and the ethanol was removed by rotary evaporation. More than 5 parts of tetrabutylammonium chloride were added thereto, and 100 parts of dichloromethane were added after stirring at 35°C for 48 hours, and stirring was continued for 5 hours. The organic phase was taken. The organic phase was washed with deionized water for several times to remove the excess tetrabutylammonium chloride, and finally rotary evaporation and vacuum drying were performed to remove dichloromethane and water to obtain a viscous ionic liquid [N4444 ][DEHP]. 1 H NMR and 13 C NMR data are shown in Figure 1 and Figure 2 As shown:

[0027] 1 H NMR(CDCl3,ppm):0.81~0.86(m,12H,4CH3),0.95~0.99(t,12H,4CH3),1.22~1.30(m,12H,6CH2),1.36~ 1.51(m,14H,6CH2+2CH), 1.58~1.69(m,8H,4CH2), 3.31~3.36(m,8H,4NCH2), 3.64~3.70(m,4H,2OCH2).

[0028] 13 C NMR(CDCl3,ppm):10.85(2CH3),13.57(4CH3),14.01(2CH3),19.59(4CH2),23.05(2CH2),23.22 (2CH2),23.91(4CH2),28.96(2CH2),30.02(2CH2),40.30(2CH),58.50(4NCH2),67.11(2OCH2).

[0029] By [N 4444 From the structural formula of ][DEHP], it can be seen that the synthetic product is the target ionic liquid [N 4444 ][DEHP].

[0030] 2) Extraction method

[0031] The rhenium waste liquid with a concentration of 0.19 g / L was used as the aqueous phase. The extractant [N 4444 ][DEHP] and diluent [C2mim][NTf2] form an organic phase, and the volume ratio of the organic phase to the aqueous phase is 1:1. The extraction temperature is 30°C and stirred for 30 minutes. Stand and separate, detect the rhenium content in the aqueous phase, calculate the extraction rate, collect the rhenium-containing organic phase, and post-treat to obtain the rhenium product.

[0032] The results are shown in Table 1. The extraction rate of rhenium is 99.32%.

[0033] Table 1. Rhenium content after adsorption

[0034]

[0035] Example 2

[0036] 1) Functionalized ionic liquids [N 4444Synthesis of ][EHEHP]

[0037] Dissolve 5 parts of 2-ethylhexyl phosphate mono-2-ethylhexyl ester in 100 parts of anhydrous ethanol by mass, and use 1 mol·L -1 The NaOH solution was adjusted to neutrality and the ethanol was removed by rotary evaporation. More than 5 parts of tetrabutylammonium chloride were added thereto, and 100 parts of dichloromethane were added after stirring at 35°C for 48 hours, and stirring was continued for 5 hours. The organic phase was taken. The organic phase was washed with deionized water for several times to remove the excess tetrabutylammonium chloride, and finally rotary evaporation and vacuum drying were performed to remove dichloromethane and water to obtain a viscous ionic liquid [N 4444 ][EHEHP]. 1 H NMR and 13 C NMR data are shown in Figure 3 and Figure 4 As shown:

[0038] 1 H NMR(CDCl3,ppm):0.76~0.85(m,12H,4CH3),0.93~0.98(t,12H,4CH3),1.19~ 1.67(m,36H,14CH2+2CH), 3.32~3.38(m,8H,4NCH2), 3.60~3.64(m,2H,OCH2).

[0039] 13 C NMR(CDCl3,ppm):10.32(CH3),10.94(CH3),13.61(4CH3),14.05(CH3),14.18(CH3),

[0040] 19.65(4CH2),23.09(CH2),23.31(CH2),23.99(4CH2),26.45(CH2),28.62(CH2),29.02(CH2),30.10 (CH2),30.77(CH2),33.52(CH2),33.80(PCH2),34.78(CH),40.55(CH),58.63(4NCH2),65.85(OCH2).

[0041] By [N 4444 From the structural formula of ][EHEHP], it can be seen that the synthesized product is the target ionic liquid [N 4444 ][EHEHP].

[0042] 2) Extraction method

[0043] The rhenium waste liquid with a concentration of 0.19 g / L was used as the aqueous phase. The extractant [N 4444][DEHP] and diluent [C2mim][NTf2] form an organic phase, and the volume ratio of the organic phase to the aqueous phase is 1:1. The extraction temperature is 30°C and stirred for 30 minutes. Stand and separate, detect the rhenium content in the aqueous phase, calculate the extraction rate, collect the rhenium-containing organic phase, and post-treat to obtain the rhenium product.

[0044] The results are shown in Table 2. The extraction rate of rhenium is 99.28%.

[0045] Table 2. Rhenium content after adsorption

[0046]

[0047] Example 3

[0048] 1) Functionalized ionic liquids [N 4444 Synthesis of ][BTMPP]

[0049] Dissolve 5 parts of bis(2,4,4-trimethylpentyl)phosphonic acid in 100 parts of anhydrous ethanol using 1 mol·L -1 The NaOH solution was adjusted to neutrality and the ethanol was removed by rotary evaporation. More than 5 parts of tetrabutylammonium chloride were added thereto, and 100 parts of dichloromethane were added after stirring at 35°C for 48 hours, and stirring was continued for 5 hours. The organic phase was taken. The organic phase was washed with deionized water for several times to remove the excess tetrabutylammonium chloride, and finally rotary evaporation and vacuum drying were performed to remove dichloromethane and water to obtain a viscous ionic liquid [N 4444 ][BTMPP]. 1 H NMR and 13 C NMR data are shown in Figure 5 and Figure 6 As shown:

[0050] 1 H NMR (CDCl3, ppm): 0.86 ~ 1.10 (m, 36H, 12CH3), 1.26 ~ 1.66 (m, 20H, 10CH2), 1.96 (s, 2H, 2CH), 3.27 ~ 3.33 (m, 8H, 4NCH2), 3.89 (s, 4H, 2PCH2).

[0051] 13 C NMR(CDCl3,ppm):13.37(4CH3),19.36(4CH2),23.73(4CH2),24.01(2CH3),25.36(2CH ),29.94(6CH3),30.82(2PCH2),42.00(CH2),43.16(CH2),53.82(2C),58.28(4NCH2).

[0052] By [N 4444From the structural formula of ][BTMPP], it can be seen that the synthesized product is the target ionic liquid [N 4444 ][BTMPP].

[0053] 2) Extraction method

[0054] The rhenium waste liquid with a concentration of 0.19 g / L was used as the aqueous phase. The extractant [N 4444 ][DEHP] and diluent [C2mim][NTf2] form an organic phase, and the volume ratio of the organic phase to the aqueous phase is 1:1. The extraction temperature is 30°C and stirred for 30 minutes. Stand and separate, detect the rhenium content in the aqueous phase, calculate the extraction rate, collect the rhenium-containing organic phase, and post-treat to obtain the rhenium product.

[0055] The results are shown in Table 3. The extraction rate of rhenium is 99.35%.

[0056] Table 3. Rhenium content after adsorption

[0057]

Claims

1. A method for constructing a green extraction system, characterized in that: The construction method is as follows: synthesize a variety of functionalized ionic liquids, then use them as extractants and diluents to prepare organic phases in a certain proportion, and then use the organic phase and the aqueous phase to form a multi-element green extraction system according to a set ratio.

2. The method for constructing a green extraction system according to claim 1, characterized in that: A variety of functionalized ionic liquids were prepared by reacting tetrabutylammonium chloride with di(2-ethylhexyl) phosphate, 2-ethylhexyl phosphate mono-2-ethylhexyl ester, and bis(2,4,4-trimethylpentyl)phosphonic acid [N 4444 ][DEHP]、[N 4444 ][EHEHP]、[N 4444 ][BTMPP].

3. The method for constructing a green extraction system according to claim 2, characterized in that: The preparation methods of various functionalized ionic liquids are as follows: 5 parts of di(2-ethylhexyl) phosphate, 2-ethylhexyl phosphate mono-2-ethylhexyl ester or di(2,4,4-trimethylpentyl)phosphonic acid are uniformly stirred with 100 parts of anhydrous ethanol, the pH is adjusted with sodium hydroxide solution, the ethanol is evaporated to remove, more than 5 parts of tetrabutylammonium chloride are added thereto, 100 parts of dichloromethane are added after stirring at room temperature for 48 hours, stirring is continued, the aqueous phase is separated, the organic phase is washed with deionized water, and finally rotary evaporation and vacuum drying are performed to remove dichloromethane and water to obtain a viscous ionic liquid [N 4444 ][DEHP]. [N 4444 ][EHEHP] and [N 4444 ][BTMPP]The synthesis method is the same as above.

4. The method for constructing a green extraction system according to claim 1, characterized in that: In the green extraction system, the diluent is 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt [C n mim][NTf2] (n = 2 to 8) or 1-alkyl-3-methylimidazolium hexafluorophosphate [C n mim][PF6](n=2~8).

5. The method for constructing a green extraction system according to claim 1, characterized in that: The water phase is rhenium-containing wastewater from smelting production.

6. The method for constructing a green extraction system according to claim 1, characterized in that: By volume ratio, extractant: diluent = 1-10:30-100.

7. The method for constructing a green extraction system according to claim 1, characterized in that: The volume ratio of the organic phase to the aqueous phase was 1:

1.

8. Use of the green extraction system constructed according to the construction method of claim 1 in extracting rhenium.

9. The use according to claim 8, characterized in that: The method is as follows: extracting rhenium using the extraction system described in claim 1, the extraction temperature is 20-60° C., stirring for 10-40 minutes, standing and stratifying to collect the rhenium-containing organic phase, and post-processing to obtain the rhenium product.

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