Extracting agent and method for separating high-economic-value metal in wastewater by using same

Abstract

The invention provides an extracting agent and a method for separating high-economic-value metal in waste water by using the extracting agent, and belongs to the technical field of waste water purification, the extracting agent takes binary heterocycle as a molecular skeleton, the binary heterocycle is large in space volume, it can be guaranteed that the molecular structure of the extracting agent presents a specific space structure, and selective extraction of target metal is guaranteed; through chemical derivatization of binary heterocycle, the length of a molecular chain segment is directionally regulated and controlled, the chemical activity of a functionalized functional group can be changed, and the dimension of spatial extension of a molecular main chain of the extraction agent is regulated and controlled; according to the invention, through esterification reaction with aliphatic cyclic mercaptan, thioester groups are formed, so that the introduction of activation sites of the extraction agent is realized, the purpose of selective chelation / complexation with target metal ions is achieved, the interference of other impurity metal ions in a wastewater solution system is avoided, and meanwhile, the extraction agent can be suitable for solution systems of various complex anion types.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater purification, and in particular to an extractant and a method for separating metals with high economic value from wastewater. Background Art

[0002] Metals with high economic value (gold, platinum, palladium, etc.) are indispensable raw materials for national economy and national defense construction, with an industrial correlation of more than 90%. They support the development of high-tech emerging industries and play an irreplaceable strategic role. At present, due to the low concentration of metals with high economic value in industrial wastewater, traditional treatment methods can be divided into: chemical precipitation, oxidation-reduction, solvent extraction, membrane separation, ion exchange, etc. Among them, the premise of chemical precipitation and oxidation-reduction methods to achieve separation, purification and enrichment of metals with high economic value is that the concentration of target metal ions in the solution is high, and low-concentration systems are difficult to achieve the expected separation purpose; membrane separation and ion exchange methods can achieve separation, purification and enrichment of low-concentration high-economic value metals, but the process flow is long, the working cycle is long, the initial investment of equipment is high, and the energy consumption is high, which restricts its application field.

[0003] Solution extraction can achieve the separation and enrichment of target metals of different concentrations and the purification of water bodies. Based on ion exchange reactions, the core of solution extraction is mainly focused on the selection of extractant types. Since the chemical properties of functionalized functional groups are affected by the types of anions in the solution, it is difficult to achieve effective separation, purification and enrichment when dealing with complex solution systems, such as a mixed solution system of gold ions and thiosulfate ions, or a mixed solution system of gold ions, platinum ions, palladium ions and glutamate anions.

[0004] In view of this, it is necessary to design an improved extractant and a method for separating high economic value metals in wastewater to solve the above problems. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides an extractant and a method for separating high economic value metals in wastewater, aiming to solve the technical problem that high economic value metals are difficult to effectively separate, purify and enrich in complex solution systems.

[0006] In a first aspect, the present application provides an extractant, the structural formula of the extractant is as follows: .

[0007] In a second aspect, the present application provides a method for separating metals of high economic value from wastewater using an extractant, wherein the extractant described in the first aspect is used for extraction, and the method comprises the following steps: Mixing and dissolving the extractant and the diluent to obtain an extractant dilution solution; The extractant diluent is added to wastewater containing target metals to achieve selective extraction of the target metals in the solution.

[0008] As a further improvement of the present application, the diluent is sulfonated kerosene.

[0009] As a further improvement of the present application, the mass ratio of the extractant to the diluent is 1:(9~59).

[0010] As a further improvement of the present application, the volume ratio of the extractant diluent to the wastewater containing the target metal is 1:(1~10).

[0011] As a further improvement of the present application, the target metal is one or more of gold, palladium and platinum.

[0012] As a further improvement of the present application, the wastewater containing the target metal is one or more of mine cyanide solution, petrochemical catalyst waste liquid, metallurgical waste liquid, and electroplating waste liquid.

[0013] As a further improvement of the present application, the anion system in the wastewater containing the target metal is one or more of chloride ion, cyanide ion, thiosulfate anion, glutamate anion, and glycine anion.

[0014] The beneficial effects of this application are: The present application provides an extractant and a method for separating metals of high economic value from wastewater. The extractant uses a binary heterocycle as a molecular skeleton. The binary cyclic molecule has a large spatial volume, which can ensure that the molecular structure of the extractant presents a unique spatial structure, thereby ensuring the selective extraction of the target metal. By chemically derivatizing the binary heterocycle, the length of the molecular chain segment can be directional regulated, the chemical activity of the functionalized functional group can be changed, and the dimension of the spatial extension of the main chain of the extractant molecule can be regulated. By reacting the esterification with an aliphatic cyclic thiol to form a thioester group, the activation site of the extractant is introduced, thereby achieving the purpose of selective chelation / complexation with the target metal ion, avoiding the interference of other impurity metal ions in the wastewater solution system, and at the same time being applicable to solution systems of various complex anion types.

[0015] The extractant of the present application presents a double activation site structure, that is, 1 mol of the extractant molecule contains 1 mol of thioester groups at both ends, which can react with the target metal ions to the greatest extent, ensuring the efficient chelating / complexing effect of the extractant.

[0016] The extractant of the present application achieves synergistic effects by regulating factors such as the spatial structure of the molecular skeleton, the length of the molecular chain segments, the number of activation sites, etc., thereby ensuring the selective and efficient extraction of the target metal, and ultimately achieving the resource utilization of metals with high economic value and the environmental protection purification of wastewater.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a physical picture of the gold-containing glycine system solution before and after extraction in Example 18 of the present application; Figure 2 is a synthetic route diagram of the extractant in Example 58 of the present application; Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the extractant in Example 58 of the present application. DETAILED DESCRIPTION

[0020] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0022] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0023] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0025] The existing technologies have the following problems in treating high economic value metals in low-concentration industrial wastewater: chemical precipitation and oxidation-reduction methods are difficult to achieve effective separation and enrichment in low-concentration systems; although membrane separation and ion exchange methods can treat low-concentration metals, their long process flow, long cycle, high equipment investment, and high energy consumption limit their application; although solution extraction can achieve separation and enrichment of metals of different concentrations, it is difficult to achieve effective separation, purification, and enrichment when treating complex solution systems due to the influence of anion types. These problems restrict the development and application of high economic value metal recovery technology.

[0026] In order to solve the technical problem that it is difficult to effectively separate, purify and enrich high economic value metals in complex solution systems, the present application provides an extractant and a method for separating high economic value metals in wastewater, wherein by preparing an extractant with a specific structure, the technical effect of resource utilization of high economic value metals and environmentally friendly purification of wastewater can be achieved.

[0027] In the first aspect, the present invention provides an extractant having the following structural formula: .

[0028] In the technical scheme of the embodiment of the present application, the extractant uses a binary heterocycle as a molecular skeleton, and the binary cyclic molecule has a large spatial volume, which can ensure that the molecular structure of the extractant presents a unique spatial structure, and ensures the selective extraction of the target metal. By chemically derivatizing the binary heterocycle, the length of the molecular chain segment can be directional regulated, which can change the chemical activity of the functionalized functional group (carboxyl group), and can also regulate the dimension of the spatial extension of the main chain of the extractant molecule. By esterification with aliphatic cyclic thiols, a thioester group is formed, and the introduction of the extractant activation site is achieved, so as to achieve the purpose of selective chelation / complexation with the target metal ion. The extractant presents a structure of double activation sites, that is, 1 mol of the extractant molecule contains 1 mol of thioester group at each end, a total of 2 mol of thioester group, which can react with the target metal ion to the greatest extent, ensuring the efficient chelation / complexation effect of the extractant.

[0029] In a second aspect, an embodiment of the present application provides a method for separating metals of high economic value from wastewater using an extractant, wherein the extractant described in the first aspect is used for extraction, and the method comprises the following steps: S1. The extractant and the diluent are mixed and dissolved to obtain an extractant diluent; S2. Adding an extractant diluent to the wastewater containing the target metal to achieve selective extraction of the target metal in the solution.

[0030] In the technical scheme of the embodiment of the present application, by using a specific extractant, metals with high economic value can be effectively separated from wastewater, thereby improving resource utilization. Specifically, in order to speed up the reaction rate, the reaction solution can be oscillated in a water bath at 25-28°C for 5-10 minutes, and the target metal in the solution can be selectively extracted. After the extraction is completed, the organic phase is separated, and the concentration of the target metal in the inorganic liquid phase solution is detected and the extraction rate is calculated. This method can selectively extract the target metal in the solution, reduce the interference of other impurities, and improve the purity of the metal. By recovering valuable metals from wastewater, pollution to the environment is reduced, which is conducive to achieving sustainable development. This method has simple steps and is easy to operate, which is conducive to promotion and application in actual production.

[0031] Further, in some embodiments, the diluent is sulfonated kerosene.

[0032] In the technical solution of the embodiment of the present application, sulfonated kerosene has good compatibility, can be effectively mixed with the extractant to form a stable extraction system, and forms two-phase separation during the extraction process, which is convenient for the extraction and recovery of metals. Sulfonated kerosene has high chemical stability and is not easy to react with metal ions or other chemicals in wastewater, thereby maintaining the effect of the extractant.

[0033] Furthermore, in some embodiments, the mass ratio of the extractant to the diluent is 1:(9~59).

[0034] In the technical solution of the embodiment of the present application, by adjusting the ratio of the extractant to the diluent, the extractant can maximize its extraction capacity and improve the recovery rate of the metal. The appropriate diluent ratio helps to form a good two-phase separation system, making it easier to separate the extraction phase and the aqueous phase, which is convenient for subsequent processing steps.

[0035] Furthermore, in some embodiments, the volume ratio of the extractant diluent to the wastewater containing the target metal is 1:(1-10).

[0036] In the technical solution of the embodiment of the present application, by adjusting the volume ratio of the extractant diluent to the wastewater, the extraction process can be optimized to ensure sufficient contact area and time to improve the extraction efficiency of metal ions. At the same time, the appropriate volume ratio can reduce the amount of extractant used, ensuring the extraction effect while reducing the processing cost.

[0037] Furthermore, in some embodiments, the target metal is one or more of gold, palladium, and platinum.

[0038] In the technical solution of the embodiment of the present application, the extractant has a highly efficient coordination ability for gold, palladium and platinum, and can efficiently and selectively extract these precious metals during the wastewater treatment process.

[0039] Furthermore, in some embodiments, the wastewater containing the target metal is one or more of mine cyanide solution, petrochemical catalyst waste liquid, metallurgical waste liquid, and electroplating waste liquid.

[0040] In the technical solution of the embodiment of the present application, the extractant can effectively extract metals with high economic value from different types of wastewater while ensuring the environmental protection, safety and economic benefits of the process.

[0041] Further, in some embodiments, the anion system in the wastewater containing the target metal is one or more of chloride ion, cyanide ion, thiosulfate anion, glutamate anion, and glycine anion.

[0042] In the technical solution of the embodiment of the present application, the extractant has high selectivity and can preferentially extract the target metal even when multiple anions coexist. At the same time, different anion systems have different acidity and alkalinity, and the extractant can remain chemically stable in the environment where the above anions exist, and is not easy to decompose or produce side reactions.

[0043] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0044] Example 1 This embodiment provides a method for separating metals of high economic value from wastewater using an extractant. The extractant used is ; Specifically including the following steps: S1. The extractant and sulfonated kerosene are mixed and dissolved in a mass ratio of 1:9 to obtain an extractant dilution solution; S2. Adjust the pH value of the industrial wastewater containing the thiosulfate solution system of gold ions to 8; at room temperature, weigh 10 mL of the above-mentioned extractant dilution solution, put it into 100 mL of industrial wastewater containing the thiosulfate system of gold ions, oscillate in a water bath oscillator at 25°C for 5 minutes, separate the organic phase, and use ICP-OES (inductively coupled plasma emission spectrometer) to detect the concentration of gold ions in the inorganic liquid phase solution, thereby calculating the extraction rate of the extractant, wherein the detection error of ICP-OES is ±2%.

[0045] Examples 2-7 and Comparative Examples 1-7 Examples 2-7 and Comparative Examples 1-7 respectively provide a method for separating high economic value metals in wastewater with an extractant. Compared with Example 1, the only difference is that the pH value of the wastewater is different, and sodium hydroxide or hydrochloric acid is used to adjust the pH value to a predetermined value, as shown in Table 1. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0046] As shown in Table 1, for the thiosulfate solution system containing gold ions, the extractant provided in the present application has a high efficiency in extracting gold within a specific pH range (8-14), and the extraction effect is more than 90%. The main reason can be attributed to the chemical properties of the anion (thiosulfate) of the solution system under different pH environments. When the pH value is less than 8, the thiosulfate in the liquid phase decomposes to produce S 2- , and gold ions generate gold sulfide precipitation, gold ions are separated from the solution system, and gold ions in the solid phase cannot achieve target ion interface migration, resulting in failure to extract. The extractant has a wide use window in the thiosulfate solution system, especially suitable for a strong alkaline environment (pH 12-14), and the gold extraction rate in a strong alkaline environment is greater than 95%.

[0047] Example 8-21 Examples 8-21 respectively provide a method for separating high economic value metals in wastewater using an extractant. Compared with Example 1, the only difference is that the wastewater to be treated is a glycine solution system containing gold, and sodium hydroxide or hydrochloric acid is used to adjust the pH value of the solution to a predetermined value, as shown in Table 2. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0048] As shown in Table 2, for the glycine solution system containing gold, the extractant provided by the present application has a high-efficiency extraction ability for gold in the pH range of 1 to 14, and the extraction effect is more than 80%. The extraction effect shows a trend of first increasing and then decreasing. The main reason can be attributed to the different existence forms of gold ions in the solution system under different pH environments. When the pH value is less than 9, the glycine solution system in the liquid phase exists in the form of glycine molecules or the protonated form of glycine acid, and has no chelating effect on gold ions. At this time, the gold ions are in the form of AuCl4 - In the form of extractant and AuCl4 - A competitive chelation reaction occurs to achieve the extraction of gold ions. When pH ≥ 9, the glycine solution system in the liquid phase exists in the form of glycine anions, which has a chelating effect on gold ions. The extractant and the glycine-gold chelate undergo a competitive chelation reaction to achieve the extraction of gold ions. At the same time, since the stability of the glycine-gold chelate is less than that of AuCl4 - In this environment, the extraction effect of gold is high. The extraction effect diagram when the pH value is 11 is as follows Figure 1 As shown, it can be seen that the solution becomes clear and transparent after extraction with the extractant. When pH ≥ 12, the gold extraction rate decreases slightly. The main reason is that under strong alkaline conditions, part of the glycine-gold chelate is hydrolyzed to form precipitated Au(OH)3, which is separated from the solution system and cannot be extracted across the interface, resulting in a decrease in the extraction efficiency, but it is still higher than 90%.

[0049] Examples 22-35 Examples 22-35 respectively provide a method for separating high economic value metals in wastewater using an extractant. Compared with Example 1, the only difference is that the wastewater to be treated is a glycine solution system containing palladium, and sodium hydroxide or hydrochloric acid is used to adjust the pH value of the solution to a predetermined value, as shown in Table 3. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0050] As shown in Table 3, for the glycine solution system containing palladium, the extractant has a high extraction capacity for palladium in the pH range of 1-14, and the extraction effect is 85% or more. The extraction effect shows a trend of first increasing and then stabilizing. The main reason can be attributed to the different existence forms of palladium ions in the solution system under different pH environments. When the pH is less than 9, the glycine anionic solution system in the liquid phase exists in the form of glycine molecules or the protonated form of glycine acid, which has no chelating effect on palladium ions. At this time, palladium ions exist in the form of PdCl4 2- In the form of extractant and PdCl4 2-A competitive chelation reaction occurs to achieve the extraction of palladium ions. When pH ≥ 12, the extraction rate of palladium remains stable. The main reason is that under strong alkaline conditions, the glycine-palladium chelate is not completely hydrolyzed to Pd(OH) x (Gly) y (palladium-hydroxy-glycine complex, x and y represent the stoichiometric numbers of hydroxyl and glycine respectively) in the form of palladium, which has good solubility and will not leave the solution system, and thus the palladium extraction rate remains stable under strong alkaline conditions (pH ≥ 12).

[0051] Examples 36-49 Examples 36-49 respectively provide a method for separating high economic value metals in wastewater using an extractant. Compared with Example 1, the only difference is that the wastewater to be treated is a glycine solution system containing platinum, and sodium hydroxide or hydrochloric acid is used to adjust the pH value of the solution to a predetermined value, as shown in Table 4. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0052] As shown in Table 4, for the glycine solution system containing platinum, the extractant has a high extraction capacity for platinum in the pH range of 1-14, and the extraction effect is more than 80%. The extraction effect shows a trend of first increasing and then stabilizing. The main reason can be attributed to the different existence forms of platinum ions in the solution system under different pH environments. When the pH is less than 9, the glycine anionic solution system in the liquid phase exists in the form of glycine molecules or protonated forms of glycine acid, which has no chelating effect on platinum ions. At this time, platinum ions exist in the form of PtCl6 2- In the form of extractant and PtCl6 2- Competitive chelation reaction occurs to achieve the extraction of platinum ions. When pH ≥ 10, the extraction rate of platinum remains stable. The main reason is that under strong alkaline conditions, the hydrolysis product of glycine-platinum chelate is Pt(OH) x (Gly) y (platinum-hydroxy-glycine complex, x and y represent the stoichiometric numbers of hydroxyl and glycine respectively) in the form of platinum, which has good solubility and will not leave the solution system, so that the extraction rate of platinum remains stable under strong alkaline conditions (pH ≥ 10).

[0053] Comparative Examples 8-21 Comparative Examples 8-21 respectively provide a method for separating high economic value metals in wastewater using an extractant. Compared with Example 1, the only difference is that the wastewater to be treated is a glycine solution system containing copper, and sodium hydroxide or hydrochloric acid is used to adjust the pH value of the solution to a predetermined value, as shown in Table 5. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0054] It can be seen from Table 5 that the extractant provided in the present application has a certain extraction ability for copper, but cannot achieve an efficient extraction effect in the entire pH range, indicating that the extractant only has a highly efficient and selective chelating effect on the target metal.

[0055] Examples 50-57 Examples 50-57 respectively provide a method for separating metals of high economic value from wastewater using an extractant, wherein the extractant provided in Example 1 is used to extract and separate target metals from a variety of coexisting ion solutions, and the specific operation steps are as follows: A series of glycine mixed solution systems containing different concentrations of gold, platinum, palladium, copper and cobalt were prepared, the pH value of the solution was adjusted to 10, 50 mL of the extractant dilution was added to 50 mL of the solution respectively, and the solution was oscillated in a water bath oscillator at 25°C for 5 min. The inorganic liquid phase was taken, and the concentration of each metal ion in the solution was detected by ICP-OES and the extraction rate was calculated.

[0056] As shown in Table 6, the extractant provided by the present application has a selective extraction effect on gold, platinum and palladium. When the metal ion concentration is ≥200ppm, copper and cobalt metal ions will not be extracted. The unique spatial structure of the extractant molecule realizes the difference between the activated functional group in the extractant and the metal extraction rate, ensuring the selective extraction of the target metal by the extractant. When the metal ion concentration is less than 200ppm, the excess extractant reacts with the impurity metal, but the generated chelate is unstable and easy to decompose, and the extraction rate of the impurity metal is less than 10%.

[0057] Embodiment 58 This example provides a method for preparing the extractant in Example 1. The synthetic route is as follows: Figure 2 As shown, the specific steps include: S1. 0.5 mol of raw material A, 100 mL of pyridine and 150 mL of dichloromethane were put into a 500 mL three-necked flask, stirred for 10 min in an ice-water bath under a nitrogen atmosphere, 0.7 mol of trifluoromethanesulfonic anhydride was slowly added dropwise to the flask, reacted at room temperature for 1 h, 100 mL of deionized water was added to quench the mixed solution, and the mixed solution was separated after standing, and the organic phase was collected, dried over anhydrous magnesium sulfate, decolorized with activated carbon, filtered, and rotary evaporated to obtain a first solid intermediate product; S2. In an ice-water bath with nitrogen atmosphere, 5 g of sodium hydride was added to 1 L of anhydrous tetrahydrofuran solution and stirred for 30 min until the solution was suspended. Then 0.5 mol of diethyl malonate was added dropwise to the solution and reacted for 0.5 h to obtain a solution system. S3. The first solid intermediate product obtained in step S1 was dissolved in 500 mL of anhydrous tetrahydrofuran solution, and added dropwise to the solution system obtained in step S2, and the reaction was allowed to react for 2 h. After the reaction was completed, the reaction was quenched with 50 mL of deionized water, and then extracted three times with 1 L of dichloromethane. The organic phase was collected, dried, filtered, and rotary evaporated to obtain a second solid intermediate product; S4. Mix the second solid intermediate obtained in step S3 with 1L of 1mol / L hydrochloric acid and heat to reflux for 24 h. After the reaction is completed, wash with 0.5L of ether for 3 times, collect the water layer, then add 0.5L of pyridine and heat to reflux for 5h. After the reaction is completed, remove pyridine by rotary evaporation, collect the brown-red oil, add 1L of 1mol / L hydrochloric acid to the brown-red oil and acidify for 3h, then extract with excess ethyl acetate, finally dry, filter, and rotary evaporate. After recrystallizing the obtained crude product with ether twice, separate it by column chromatography with a mixed solution of toluene and ethyl acetate (volume ratio 1:1), and rotary evaporate to obtain white crystalline product B with a yield of 21%; S5. Add 0.05 mol of product B and raw material C at a molar ratio of 1:8 to 500 mL of a mixed solution of dimethyl sulfoxide and acetonitrile (volume ratio 4:1), add 1 mmol of n-butyl titanate solution to 20 mL of a mixed solution of dimethyl sulfoxide and acetonitrile (volume ratio 4:1), and add the mixture to the mixed solution of product B and raw material C in batches, and react for 12 hours. After the reaction is completed, remove the organic solvent by vacuum distillation, dissolve the oil in excess ethanol, ultrasonically dissolve for 30 minutes, filter, collect the undissolved matter, and finally dissolve the undissolved matter in a small amount of a mixed solution of dimethyl sulfoxide and acetonitrile. After the solution is completely dissolved, rotary evaporate to obtain a transparent oily product D, which is the extractant, with a yield of 43%. Its nuclear magnetic resonance hydrogen spectrum is as follows: Figure 3 shown.

[0058] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. An extractant, characterized in that The structural formula of the extractant is as follows: 。 2. A method for separating metals of high economic value from wastewater using an extractant, wherein the extractant according to claim 1 is used for extraction, characterized in that: The following steps are involved: Mixing and dissolving the extractant and the diluent to obtain an extractant dilution solution; The extractant diluent is added to wastewater containing target metals to achieve selective extraction of the target metals in the solution.

3. The method for separating high economic value metals from wastewater by an extractant according to claim 2, characterized in that: The diluent is sulfonated kerosene.

4. The method for separating high economic value metals from wastewater by an extractant according to claim 3, characterized in that: The mass ratio of the extractant to the diluent is 1:(9-59).

5. The method for separating high economic value metals from wastewater by an extractant according to claim 2, characterized in that: The volume ratio of the extractant diluent to the wastewater containing the target metal is 1:(1-10).

6. The method for separating high economic value metals from wastewater by an extractant according to claim 2, characterized in that: The target metal is one or more of gold, palladium and platinum.

7. The method for separating high economic value metals from wastewater by an extractant according to claim 6, characterized in that: The wastewater containing the target metal is one or more of mining cyanide solution, petrochemical catalyst waste liquid, metallurgical waste liquid, and electroplating waste liquid.

8. The method for separating high economic value metals from wastewater by an extractant according to claim 7, characterized in that: The anion system in the wastewater containing the target metal is one or more of chloride ion, cyanide ion, thiosulfate anion, glutamate anion, and glycine anion.

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