Extraction agent and preparation method and application thereof

Abstract

The present application provides an extractant and its preparation method and application, which belongs to the field of heavy metal purification in industrial wastewater, wherein the selective extraction of target metals by the extractant is regulated by changing the number of aliphatic chain primary alcohols and the length of their segments and the position of functional groups, and the diquaternary ammonium salt fragment structure ensures efficient extraction of target metals. Quaternary ammonium salts are linked by straight or cyclic aliphatic chain segments, which can be miscible with various solvents to the greatest extent, ensuring the spatial extension range of terminal diquaternary ammonium salts, and can achieve effective complexation with tungsten and molybdenum ions, which can meet various application scenarios and broaden the working environment of the extractant; in addition, the nitrogen atoms in the molecular structure of the extractant are derivatized by a specific number of aliphatic primary alcohols, which not only improves the selective extraction of molybdenum and tungsten, but also has good chemical stability and is difficult to be oxidized by conventional oxidants.

Description

Technical Field

[0001] The invention relates to the technical field of heavy metal purification in industrial wastewater, and in particular to an extractant and a preparation method and application thereof. Background Art

[0002] In order to solve the problem of heavy metal pollution in soil, chemical extraction is used to remove metal pollutants in soil. Due to its simple process operation, it is widely used in the field of remediation of contaminated sites. In the chemical extraction process, the selection of extractant is particularly important. While ensuring the extraction of target metal ions, the feasibility of the subsequent stripping process must also be taken into account. The separation and recycling of metals in industrial wastewater has both environmental and economic significance.

[0003] At present, the extractants used in the field of wastewater treatment containing tungsten and molybdenum have certain limitations: First, poor selectivity: it cannot meet the selective extraction of target metal ions in complex metal solutions. During the extraction stage, a large number of other metal ions will be extracted together. Second, poor antioxidant ability: in industry, the stripping stage of tungsten and molybdenum extracts requires the introduction of certain oxidants into the stripping agent. The introduction of oxidants will cause the extractant to react, and thus it is impossible to recover and recycle it. The above defects have greatly increased the cost of the enterprise.

[0004] In the prior art, the patent with publication number CN118480034A provides a degradable and environmentally friendly extractant and a method for separating molybdenum, tungsten and rhenium from industrial wastewater. The extractant used in the method has a straight-chain diamide as a molecular skeleton and can show good extraction effects on molybdenum, tungsten and rhenium. However, in the existing industry, sometimes only an extractant capable of extracting molybdenum and tungsten is needed, which requires the extractant to have high efficiency and selectivity to better meet specific industrial needs.

[0005] In view of this, it is necessary to design an extractant and a preparation method and application thereof to solve the above problems. Summary of the invention

[0006] In view of the technical problems existing in the background technology, the present application provides an extractant and a preparation method and application thereof, aiming to solve the technical problems of poor selectivity of target metal ions in existing extractants and poor antioxidant capacity of the extractants.

[0007] In a first aspect, the present invention provides a method for preparing an extractant, comprising the following steps:

[0008] S1. Add N-di-2-hydroxyethylamine and dibromododecane to anhydrous ethanol in a first predetermined ratio, and then add sodium hydroxide to obtain a mixed solution 1, and then place the mixed solution 1 at a predetermined temperature for reaction;

[0009] The first predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to dibromododecane is 6-8:1;

[0010] In the mixed solution 1, the concentration of N-di-2-hydroxyethylamine is 0.3-0.8 mol / L, the concentration of dibromododecane is 0.05-0.1 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L;

[0011] The reaction temperature is 50-100°C and the reaction time is 24-72h;

[0012] S2, distilling and extracting the mixed solution after the reaction to obtain an oily intermediate product, namely, extractant A-mid;

[0013] S3, adding the extractant A-mid and bromoethanol to anhydrous ethanol in a second predetermined ratio to prepare a second mixed solution, and then placing the second mixed solution at a predetermined temperature for reaction;

[0014] The second predetermined ratio is: the molar ratio of the extractant A-mid to bromoethanol is 1:3-5;

[0015] The reaction temperature is 50-100°C and the reaction time is 24-48 hours;

[0016] S4, the mixed solution after the reaction is subjected to a distillation-extraction treatment to obtain the target product, extractant A.

[0017] The present application also provides a method for preparing an extractant, comprising the following steps:

[0018] Sa. Add N-di-2-hydroxyethylamine and 1,4-bromocyclohexane to anhydrous ethanol in a third predetermined ratio, and then add sodium hydroxide to obtain a mixed solution three; and then place the mixed solution three at a predetermined temperature for reaction;

[0019] The third predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to 1,4-bromocyclohexane is 5-10:1;

[0020] In the mixed solution three, the concentration of N-di-2-hydroxyethylamine is 0.25-1 mol / L, the concentration of 1,4-bromocyclohexane is 0.05-0.1 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L;

[0021] The reaction temperature is 50-100°C and the reaction time is 24-72h;

[0022] Sb, distilling and extracting the mixed solution after the reaction to obtain an oily intermediate product, namely, extractant B-mid;

[0023] Sc, adding the extractant B-mid and bromoethanol to anhydrous ethanol-cyclohexane solution in a fourth predetermined ratio to prepare a mixed solution four, and then placing the mixed solution four at a predetermined temperature for reaction;

[0024] The fourth predetermined ratio is: the volume ratio of anhydrous ethanol to cyclohexane in the anhydrous ethanol-cyclohexane solution is 4-9:1, and the molar ratio of the extractant B-mid to bromoethanol is 1:3-5;

[0025] The reaction temperature is 50-100°C and the reaction time is 24-48 hours;

[0026] Sd, and the mixed solution after the reaction is further subjected to distillation-extraction treatment to obtain the target product, extractant B.

[0027] In this embodiment, a quaternary ammonium salt is derivatized with an aliphatic chain primary alcohol to form a diquaternary ammonium salt fragment structure. The quaternary ammonium salt is linked by straight-chain or cyclic aliphatic chain segments, which can ensure the maximum miscibility with various solvents in industrial wastewater. In addition, the nitrogen atoms in the extractant are derivatized with an aliphatic primary alcohol, which not only improves the selective extraction of molybdenum and tungsten, but also has good chemical stability and is difficult to be oxidized by conventional oxidants.

[0028] In a second aspect, an embodiment of the present application provides an extractant, wherein the extractant includes an extractant A; the structural formula of the extractant A is:

[0029] ;

[0030] Among them, 6≤n≤12.

[0031] The present application also provides an extractant, which further includes an extractant B; the extractant B has a structural formula of:

[0032] ;

[0033] Among them, 2≤n≤4.

[0034] In this embodiment, the nitrogen atoms in the molecular structures of extractants A and B are derivatized with a specific number of aliphatic primary alcohols, which not only improve the selective extraction of molybdenum and tungsten, but also have good chemical stability and are difficult to be oxidized by conventional oxidants. In addition, the long-chain aliphatic segments of extractant A are arranged alternately in a zigzag shape, and as the carbon chain grows, spatial accumulation is avoided, further achieving effective complexation of active sites with tungsten and molybdenum ions; the cyclic aliphatic segments in extractant B are not in the same plane, showing spatial dislocation, ensuring the spatial extension range of the terminal diquaternary ammonium salt, and can achieve effective complexation with tungsten and molybdenum ions.

[0035] In a third aspect, an embodiment of the present application provides an application of an extractant, wherein any one of the above extractants is used to separate molybdenum and tungsten from industrial wastewater, specifically comprising the following steps:

[0036] SA, mixing the extractant with sulfonated kerosene, dissolving by ultrasonication, and obtaining a diluent;

[0037] SB, adjust the pH value of industrial wastewater solutions containing molybdenum and tungsten to acidic;

[0038] SC. Add the diluent in step SA to the solution obtained in step SB to extract molybdenum and tungsten in the industrial wastewater solution.

[0039] In the technical solution of the embodiment of the present application, by using an extractant that changes the type of derivatized functional groups, the number of functional groups, the length of the functional group chain segment, the molecular main chain structure and its steric hindrance, a qualitative change in the chelating effect of molybdenum and tungsten ions is achieved, thereby achieving efficient and selective extraction of molybdenum and tungsten, thereby improving the efficiency and selectivity of the extraction process.

[0040] In some embodiments, the industrial wastewater containing molybdenum and tungsten contains molybdenum in the form of HMoO4 - 、H2MoO4、MoO2 2+ exists in one or more forms.

[0041] In some embodiments, the industrial wastewater containing molybdenum and tungsten contains tungsten in the form of HWO4 - 、H2WO4、WO2 2+ One or more forms of exist.

[0042] In some embodiments, in the diluent, the volume ratio of the extractant to sulfonated kerosene is 1:10-100.

[0043] In some embodiments, the pH value in step SB ranges from 1 to 6.

[0044] In this embodiment, the pH of the industrial wastewater containing molybdenum and tungsten is adjusted to a range of 1 to 6 to avoid the existence of quaternary ammonium salts under alkaline conditions, which are converted from ammonium salts to amines and lose the activation site N + Therefore, it can ensure that the extractant can efficiently extract molybdenum and tungsten, and the extraction effect can reach more than 95%.

[0045] In some embodiments, the industrial wastewater containing molybdenum and tungsten includes one or more of ore solution, catalyst waste liquid, metallurgical waste liquid, and electronic waste leaching solution.

[0046] In this embodiment, by using the modified extractant, even if the quaternary ammonium salt is linked by straight-chain or cyclic aliphatic chain segments, it can be miscible with various solvents to the greatest extent, so as to meet the application scenarios of various industrial wastewaters, thereby broadening the working environment of the extractant.

[0047] 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

[0048] 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.

[0049] Figure 1 This is a schematic diagram of the preparation principle of the extractant A in the embodiment of the present application;

[0050] Figure 2 This is a schematic diagram of the preparation principle of the extractant B in the embodiment of the present application;

[0051] Figure 3 The synthetic route diagram of the extractant A in Example 1 of the present application;

[0052] Figure 4 This is the synthesis route diagram of the extractant B in Example 7 of the present application. DETAILED DESCRIPTION

[0053] The following embodiments of the technical solution of the present application are 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0058] In the prior art, tributyl phosphate is often used as an extractant in the field of wastewater treatment containing tungsten and molybdenum. However, tributyl phosphate has certain toxicity and will have long-term effects on aquatic organisms. In addition, there are certain limitations in the banning of tributyl phosphate in the food field: and in the extraction stage, a large number of other metal ions will be extracted together. In addition, in industry, the stripping stage of tungsten and molybdenum extracts requires the introduction of a certain oxidant into the stripping agent, and the introduction of the oxidant easily leads to oxidation of the extractant, and thus its recovery and recycling cannot be achieved. Therefore, it is particularly important to prepare an extractant that can not only extract molybdenum and tungsten efficiently and selectively, but also ensure that it is not easily oxidized during the extraction process.

[0059] In order to solve the above-mentioned technical problems, the present application provides an extractant and a preparation method and application thereof, wherein the selective extraction of the target metal by the extractant is regulated by changing the number of aliphatic chain primary alcohols, the length of their chain segments, and the position of their functional groups; and by derivatizing the nitrogen atoms in the extractant with aliphatic primary alcohols, the selective extraction of molybdenum and tungsten is improved, thereby ensuring the technical effect that the extractant is difficult to be oxidized by an oxidant.

[0060] Please refer to Figure 1 In a first aspect, the present invention provides a method for preparing an extractant, comprising the following steps:

[0061] S1. Add N-di-2-hydroxyethylamine and dibromododecane to anhydrous ethanol in a first predetermined ratio, and then add sodium hydroxide to obtain a mixed solution 1, and then place the mixed solution 1 at a predetermined temperature for reaction;

[0062] S2, distillation-extraction treatment is carried out on the mixed solution after the reaction, and the specific process is:

[0063] Distilling the mixed solution after the reaction, and collecting the solid phase;

[0064] Add deionized water to the solid phase 1, perform ultrasonic dissolution and filtration in sequence, and collect the oily substance W;

[0065] Adding ether aqueous solution to the oily substance W for extraction, and collecting an organic phase 1;

[0066] The organic phase 1 is sequentially dried and filtered to collect the liquid phase 1, and then the liquid phase 1 is distilled to obtain an oily intermediate product, namely, an extractant A-mid;

[0067] S3, adding the extractant A-mid and bromoethanol to anhydrous ethanol in a second predetermined ratio to prepare a second mixed solution, and then placing the second mixed solution at a predetermined temperature for reaction;

[0068] S4, distilling and extracting the mixed solution after the reaction, the specific process is:

[0069] The mixed solution 2 after the reaction is distilled to obtain a viscous substance 1;

[0070] After adding ether to the viscous substance 1, washing and filtering are performed in sequence to collect the solid phase 2;

[0071] Deionized water (ie, solid phase two-deionized water solution) is added to the solid phase two for ultrasonic dissolution, and then acetone is added for recrystallization, and the target product, extractant A, is obtained after drying.

[0072] Further, in some embodiments, in step S1, the first predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to dibromododecane is 6-8:1; (wherein the amount of anhydrous ethanol is sufficient to completely dissolve the solute);

[0073] In the mixed solution 1, the concentration of N-di-2-hydroxyethylamine is 0.3-0.8 mol / L, the concentration of dibromododecane is 0.05-0.1 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L;

[0074] The reaction temperature is 50-100°C and the reaction time is 24-72h;

[0075] In step S2, the volume of diethyl ether in the diethyl ether aqueous solution is 50%; the diethyl ether aqueous solution is sufficient to completely dissolve the solute;

[0076] In step S3, the second predetermined ratio is: the molar ratio of the extractant A-mid to bromoethanol is 1:3-5; the amount of anhydrous ethanol is sufficient to completely dissolve the solute; the reaction temperature is 50-100° C., and the reaction time is 24-48 hours;

[0077] In step S4, the ether is capable of completely dissolving the solute; the volume ratio of the solid phase di-deionized water solution to the acetone is 100-10:1.

[0078] like Figure 2 As shown, the present application embodiment also provides a method for preparing an extractant, comprising the following steps:

[0079] Sa. Add N-di-2-hydroxyethylamine and 1,4-bromocyclohexane to anhydrous ethanol in a third predetermined ratio, and then add sodium hydroxide to obtain a mixed solution three; and then place the mixed solution three at a predetermined temperature for reaction;

[0080] Sb, the mixed solution after the reaction is subjected to distillation-extraction treatment, the specific steps are:

[0081] The mixed solution after the reaction is distilled to collect the oily substance;

[0082] Add deionized water to the oily substance, perform ultrasonic dissolution and filtration in sequence, and collect the oily substance M;

[0083] Adding cyclohexane aqueous solution to the substance M for extraction, and collecting organic phase 2;

[0084] The organic phase 2 is sequentially dried and filtered to collect the liquid phase 2, and then the liquid phase 2 is distilled to obtain an oily intermediate product, namely, the extractant B-mid;

[0085] Sc, adding the extractant B-mid and bromoethanol to anhydrous ethanol-cyclohexane solution in a fourth predetermined ratio to prepare a mixed solution four, and then placing the mixed solution four at a predetermined temperature for reaction;

[0086] Sd, the mixed solution after the reaction is further subjected to distillation-extraction treatment, the specific steps are:

[0087] The mixed solution 4 after the reaction is distilled to obtain a viscous substance 2;

[0088] After adding ether to the viscous substance 2, washing and filtering are performed in sequence to collect the solid phase 3;

[0089] Deionized water (ie, solid phase three-deionized water solution) is added to the solid phase three for ultrasonic dissolution, and then acetone is added for recrystallization, and the target product, extractant B, is obtained after drying.

[0090] Further, in some embodiments, in step Sa, the third predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to 1,4-bromocyclohexane is 5-10:1; (wherein the amount of anhydrous ethanol is sufficient to completely dissolve the solute);

[0091] In the mixed solution three, the concentration of N-di-2-hydroxyethylamine is 0.25-1 mol / L, the concentration of 1,4-bromocyclohexane is 0.05-0.1 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L;

[0092] The reaction temperature is 50-100°C and the reaction time is 24-72h;

[0093] In step Sb, the volume of cyclohexane in the cyclohexane aqueous solution is 50%; the ether aqueous solution is sufficient to completely dissolve the substance M;

[0094] In step Sc, the fourth predetermined ratio is: the volume ratio of anhydrous ethanol to cyclohexane in the anhydrous ethanol-cyclohexane solution is 4-9:1, the molar ratio of the extractant B-mid to bromoethanol is 1:3-5; the anhydrous ethanol-cyclohexane solution is sufficient to completely dissolve the solute; the reaction temperature is 50-100° C., and the reaction time is 24-48 hours;

[0095] In step Sd, the ether is capable of completely dissolving the solute, including impurities, to achieve the effect of removing impurities; the volume ratio of the solid phase tri-deionized water solution to the acetone is 100-10:1;

[0096] Among them, aliphatic chain primary alcohols are derivatized to quaternary ammonium salts to form a diquaternary ammonium salt fragment structure. The quaternary ammonium salts are linked by straight or cyclic aliphatic chain segments, which can ensure the maximum miscibility with various solvents in industrial wastewater. In addition, the nitrogen atoms in the extractant are derivatized with aliphatic primary alcohols, which not only improves the selective extraction of molybdenum and tungsten, but also has good chemical stability and is difficult to be oxidized by conventional oxidants.

[0097] Please refer to Figure 2 In a second aspect, an embodiment of the present application provides an extractant, wherein the extractant includes an extractant A; the extractant A is prepared according to the above-mentioned preparation method;

[0098] The structural formula of the extractant A is:

[0099] ;

[0100] Among them, 6≤n≤12.

[0101] The length of the chain segment is regulated by adjusting the number of methylene groups in the main chain of the molecule (6≤n≤12); the molecular spatial structure of the extractant is regulated by introducing six hydroxyl functional groups at the end of the molecule while changing the number of aliphatic chain primary alcohols, thereby achieving the selective extraction of the target metal by the extractant. The diquaternary ammonium salt fragment structure in the molecular chain segment ensures the efficient extraction of the target metal. The long-chain aliphatic chain segment of the extractant A is arranged in a zigzag alternating pattern. As the carbon chain grows, the accumulation of space is avoided, and the active site can also be effectively complexed with tungsten and molybdenum ions.

[0102] The present application embodiment provides an extractant, which further comprises an extractant B; the extractant B is prepared according to the above preparation method; the structural formula of the extractant B is:

[0103] ;

[0104] Among them, 2≤n≤4.

[0105] By introducing a cyclic aliphatic chain segment, the structure of the extractant B is spatially dislocated, ensuring the spatial extension range of the terminal diquaternary ammonium salt, and achieving effective complexation with tungsten and molybdenum ions.

[0106] The nitrogen atoms in the molecular structures of extractants A and B are derivatized with a specific number of aliphatic primary alcohols, which improve the selective extraction of molybdenum and tungsten, have good chemical stability and are difficult to be oxidized by conventional oxidants. The long-chain aliphatic segments of extractant A are arranged alternately in a zigzag shape. As the carbon chain grows, the accumulation of space is avoided, and the active sites are further effectively complexed with tungsten and molybdenum ions; the cyclic aliphatic segments in extractant B are not in the same plane, showing spatial dislocation, which ensures the spatial extension range of the terminal diquaternary ammonium salt and can achieve effective complexation with tungsten and molybdenum ions.

[0107] In a third aspect, an embodiment of the present application provides an application of an extractant, using any of the above-mentioned extractants to separate molybdenum and tungsten from industrial wastewater, specifically comprising the following steps:

[0108] SA, mixing the extractant with sulfonated kerosene, dissolving by ultrasonication, and obtaining a diluent;

[0109] SB, adjust the pH value of industrial wastewater solutions containing molybdenum and tungsten to acidic;

[0110] SC. Add the diluent in step SA to the solution obtained in step SB to extract molybdenum and tungsten in the industrial wastewater solution.

[0111] Among them, by using extractants that change the type of derivatized functional groups, the number of functional groups, the length of the functional group chain segments, the molecular main chain structure and its steric hindrance, a qualitative change in the chelating effect of molybdenum and tungsten ions is achieved, thereby achieving efficient and selective extraction of molybdenum and tungsten.

[0112] Furthermore, in some embodiments, the industrial wastewater containing molybdenum and tungsten contains molybdenum in the form of HMoO4 - 、H2MoO4、MoO2 2+ One or more forms of exist.

[0113] Furthermore, in some embodiments, the industrial wastewater containing molybdenum and tungsten contains tungsten in the form of HWO4 - 、H2WO4、WO2 2+ One or more forms of exist.

[0114] Furthermore, in some embodiments, in the diluent, the volume ratio of the extractant to sulfonated kerosene is 1:10-100.

[0115] Furthermore, in some embodiments, the pH value in step SB is in the range of 1 to 6.

[0116] In the technical solution of the embodiment of the present application, the pH of the industrial wastewater containing molybdenum and tungsten is adjusted to a range of 1 to 6 to avoid the existence of quaternary ammonium salt under alkaline conditions, which is converted from ammonium salt to amine and loses the activation site N + Therefore, it can ensure that the extractant can efficiently extract molybdenum and tungsten, and the extraction effect can reach more than 95%.

[0117] Furthermore, in some embodiments, the industrial wastewater containing molybdenum and tungsten includes one or more of ore solution, catalyst waste liquid, metallurgical waste liquid, and electronic waste leaching solution.

[0118] In the technical solution of the embodiment of the present application, by using a modified extractant, even if the quaternary ammonium salt is linked by a straight chain or a cyclic aliphatic chain segment, it can be miscible with various solvents to the greatest extent, so as to meet the application scenarios of various industrial wastewaters, thereby broadening the working environment of the extractant.

[0119] 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.

[0120] Example 1

[0121] Preparation of Extractant A:

[0122] like Figure 3 As shown, the preparation method of extractant A comprises the following steps:

[0123] S1. Add N-di-2-hydroxyethylamine and dibromododecane to anhydrous ethanol in a first predetermined ratio, and then add sodium hydroxide to obtain a mixed solution 1, and then place the mixed solution 1 at a predetermined temperature for reaction;

[0124] The first predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to dibromododecane is 6:1;

[0125] In the mixed solution 1, the concentration of N-di-2-hydroxyethylamine is 0.3 mol / L, the concentration of dibromododecane is 0.05 mol / L, and the concentration of sodium hydroxide is 0.1 mol / L;

[0126] The reaction temperature was 75°C and the reaction time was 48h;

[0127] S2, distilling the mixed solution 1 after the reaction and collecting the solid phase 1;

[0128] Deionized water is added to the solid phase 1, and ultrasonic dissolution and filtration are performed in sequence to collect the oily substance W;

[0129] Adding ether aqueous solution to the substance W for extraction, and collecting organic phase 1;

[0130] The organic phase 1 is sequentially dried and filtered to collect the liquid phase 1, and then the liquid phase 1 is distilled to obtain an oily intermediate product, namely, the extractant A-mid;

[0131] The volume of diethyl ether in the diethyl ether aqueous solution is 50%;

[0132] S3, adding the extractant A-mid and bromoethanol to anhydrous ethanol in a second predetermined ratio to prepare a second mixed solution, and then placing the second mixed solution at a predetermined temperature for reaction;

[0133] In step S3, the second predetermined ratio is: the molar ratio of the extractant A-mid to bromoethanol is 1:3; the reaction temperature is 75° C., and the reaction time is 48 hours;

[0134] S4, distilling the mixed solution 2 after the reaction to obtain a viscous substance 1;

[0135] After adding ether to the viscous substance 1, washing and filtering are performed in sequence to collect the solid phase 2;

[0136] Deionized water was added to the solid phase II for ultrasonic dissolution, and then acetone was added for recrystallization, and the target product extractant A was obtained after drying; the ratio of the viscous substance I to the ether was 10 g:1 mL; the volume ratio of the solid phase II-deionized water solution to the acetone was 50:1;

[0137] The structural formula of the extractant A is:

[0138] ;

[0139] Among them, 6≤n≤12.

[0140] Application of extraction agent:

[0141] The extraction agent A is used to separate molybdenum and tungsten from industrial wastewater, which specifically includes the following steps:

[0142] SA, mixing the extractant A with sulfonated kerosene, dissolving them by ultrasonication, and obtaining a diluent; in the diluent, the volume ratio of the extractant A to the sulfonated kerosene is 1:10.

[0143] SB, adjust the pH value of the industrial wastewater solution containing molybdenum and tungsten to 1; the industrial wastewater containing molybdenum and tungsten includes one or more of ore solution, catalyst waste liquid, metallurgical waste liquid, and electronic waste leaching solution; in the industrial wastewater containing molybdenum and tungsten, molybdenum is in the form of HMoO4 - 、H2MoO4、MoO2 2+ Tungsten exists in the form of HWO4 - 、H2WO4、WO2 2+ exists in the form of.

[0144] SC. At room temperature, add the diluent (100 mL) in step SA to the solution (50 mL) obtained in step SB, and shake in a water bath oscillator for 5 min, then take the organic phase, and detect the concentrations of molybdenum and tungsten in the inorganic liquid phase solution by ICP-OES, and finally calculate the extraction rate of extractant A.

[0145] Embodiment 2~6

[0146] Examples 2 to 6 respectively provide an application of an extractant, which differs from Example 1 in that step SB adjusts the pH value of the industrial wastewater solution containing molybdenum and tungsten differently. The pH values ​​of Examples 2 to 6 are 2, 3, 4, 5, and 6, respectively. The remaining steps are consistent with Example 1 and are not repeated here.

[0147] Comparative Examples 1 to 3

[0148] Comparative Examples 1 to 3 respectively provide an application of an extractant, which differs from Example 1 in that step SB adjusts the pH value of the industrial wastewater solution containing molybdenum and tungsten differently. The pH values ​​of Comparative Examples 1 to 3 are 7, 8, and 12, respectively. The remaining steps are consistent with Example 1 and are not repeated here.

[0149] The effect of pH on the adsorption of molybdenum and tungsten by the extractant A used in Examples 1 to 6 and Comparative Examples 1 to 3 is shown in Table 1.

[0150] Table 1 Extraction capacity of extractant A for molybdenum and tungsten at different pH values

[0151]

[0152] Note: “—” indicates that the value is below the detection limit of ICP-OES.

[0153] As shown in Table 1, when the pH of industrial wastewater containing molybdenum and tungsten is adjusted in the range of 1-6, extractant A can extract molybdenum and tungsten efficiently, and the extraction effect is more than 95%; when the pH of industrial wastewater containing molybdenum and tungsten is ≥7, the extraction ability of extractant A is negatively affected. The main reason is that the existence form of quaternary ammonium salt under alkaline conditions is transformed from ammonium salt to amine, and the activation site N is lost. + .

[0154] The extractant A prepared in Example 1 was used to extract and separate molybdenum and tungsten from various coexisting ion solutions. The specific operation steps are as follows:

[0155] A series of mixed solutions containing different concentration ratios of molybdenum, tungsten and iron, zinc, tin and rhenium were prepared. 10 ml of extractant A was added to 10 ml of the mixed solution, and after shaking for 5 minutes, the inorganic liquid phase was taken and the concentration of each metal ion in the solution was detected by ICP-OES to calculate the extraction rate.

[0156] The extraction effects of extractant A on various metal ions in the blend solution are shown in Table 2.

[0157] Table 2 Extraction ability of extractant A for each metal ion in the blend solution

[0158]

[0159] Note: “—” indicates that the value is lower than the detection limit of ICP-OES.

[0160] As can be seen from Table 2, extractant A has excellent extraction selectivity for molybdenum and tungsten, but basically does not extract other coexisting metal ions such as tin, zinc, aluminum and rhenium. The main reason is attributed to the unique molecular structure of the prepared extractant A.

[0161] Example 7

[0162] Preparation of Extractant B:

[0163] like Figure 4 As shown, the preparation method of extractant B comprises the following steps:

[0164] Sa. Add N-di-2-hydroxyethylamine and 1,4-bromocyclohexane to anhydrous ethanol in a third predetermined ratio, and then add sodium hydroxide to obtain a mixed solution three; and then place the mixed solution three at a predetermined temperature for reaction;

[0165] The third predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to 1,4-bromocyclohexane is 5:1;

[0166] In the mixed solution three, the concentration of N-di-2-hydroxyethylamine is 0.25 mol / L, the concentration of 1,4-bromocyclohexane is 0.05 mol / L, and the concentration of sodium hydroxide is 0.1 mol / L;

[0167] The reaction temperature was 75°C and the reaction time was 48h;

[0168] Sb, distilling the mixed solution after the reaction and collecting the oil;

[0169] Add deionized water to the oily substance, perform ultrasonic dissolution and filtration in sequence, and collect substance M;

[0170] Adding cyclohexane aqueous solution to the substance M for extraction, and collecting organic phase 2;

[0171] The organic phase 2 is sequentially dried and filtered to collect the liquid phase 2, and then the liquid phase 2 is distilled to obtain an oily intermediate product, namely, the extractant B-mid;

[0172] In step Sb, the volume of cyclohexane in the cyclohexane aqueous solution is 50%;

[0173] Sc, adding the extractant B-mid and bromoethanol to anhydrous ethanol-cyclohexane solution in a fourth predetermined ratio to prepare a mixed solution four, and then placing the mixed solution four at a predetermined temperature for reaction;

[0174] The fourth predetermined ratio is: the volume ratio of anhydrous ethanol to cyclohexane in the anhydrous ethanol-cyclohexane solution is 4:1, the molar ratio of the extractant B-mid to bromoethanol is 1:3; the reaction temperature is 75° C., and the reaction time is 48 hours;

[0175] Sd, distilling the mixed solution 4 after the reaction to obtain a viscous substance 2;

[0176] After adding ether to the viscous substance 2, washing and filtering are performed in sequence to collect the solid phase 3;

[0177] Deionized water is added to the solid phase three for ultrasonic dissolution, and then acetone is added for recrystallization. After drying, the target product, extractant B, is obtained.

[0178] The ratio of the viscous substance 2 to the ether is 10 g:1 mL; the volume ratio of the solid phase tri-deionized water solution to the acetone is 50:1.

[0179] The structural formula of the extractant B is:

[0180] ;

[0181] Among them, 2≤n≤4.

[0182] Application of extraction agent:

[0183] The extraction agent B is used to separate molybdenum and tungsten from industrial wastewater, which specifically includes the following steps:

[0184] SA, mixing the extractant B with sulfonated kerosene, dissolving them by ultrasonication, and obtaining a diluent; in the diluent, the volume ratio of the extractant B to the sulfonated kerosene is 1:10.

[0185] SB, adjust the pH value of the industrial wastewater solution containing molybdenum and tungsten to 1; the industrial wastewater containing molybdenum and tungsten includes one or more of ore solution, catalyst waste liquid, metallurgical waste liquid, and electronic waste leaching solution; in the industrial wastewater containing molybdenum and tungsten, molybdenum is in the form of HMoO4 - 、H2MoO4、MoO2 2+ Tungsten exists in the form of HWO4 - 、H2WO4、WO2 2+ exists in the form of.

[0186] SC. At room temperature, add the diluent (100 mL) in step SA to the solution (50 mL) obtained in step SB, and shake in a water bath oscillator for 5 min, then take the organic phase, and detect the concentrations of molybdenum and tungsten in the inorganic liquid phase solution by ICP-OES, and finally calculate the extraction rate of extractant B.

[0187] Embodiments 8 to 12

[0188] Examples 8 to 12 respectively provide an application of an extractant, which differs from Example 7 in that step SB adjusts the pH value of the industrial wastewater solution containing molybdenum and tungsten differently. The pH values ​​of Examples 8 to 12 are 2, 3, 4, 5, and 6, respectively. The remaining steps are consistent with Example 7 and will not be repeated here.

[0189] Comparative Examples 4 to 6

[0190] Comparative Examples 4 to 6 respectively provide an application of an extractant, which differs from Example 7 in that step SB adjusts the pH value of the industrial wastewater solution containing molybdenum and tungsten differently. The pH values ​​of Comparative Examples 4 to 6 are 7, 8, and 12, respectively. The remaining steps are consistent with Example 7 and are not repeated here.

[0191] The effect of pH on the adsorption of molybdenum and tungsten by the extractant B used in Examples 7 to 12 and Comparative Examples 4 to 6 is shown in Table 3.

[0192] Table 3 Extraction capacity of extractant B for molybdenum and tungsten at different pH values

[0193]

[0194] Note: “—” indicates that the value is below the detection limit of ICP-OES.

[0195] As shown in Table 3, when the pH of industrial wastewater containing molybdenum and tungsten is adjusted in the range of 1-6, extractant B can extract molybdenum and tungsten efficiently, and the extraction effect is more than 95%. When the pH of industrial wastewater containing molybdenum and tungsten is ≥7, the extraction ability of extractant B is negatively affected. The main reason is that the existence form of quaternary ammonium salt under alkaline conditions is transformed from ammonium salt to amine, and the activation site N is lost. + .

[0196] The extractant B prepared in Example 7 was used to extract and separate molybdenum and tungsten from various coexisting ion solutions. The specific operation steps are as follows:

[0197] A series of mixed solutions containing different concentration ratios of molybdenum, tungsten, aluminum, zinc, and tin were prepared. 10 ml of extractant B was added to 10 mL of the mixed solution, and after shaking for 5 minutes, the inorganic liquid phase was taken and the concentration of each metal ion in the solution was detected by ICP-OES to calculate the extraction rate.

[0198] The extraction effects of extractant B on each metal ion in the blend solution are shown in Table 4.

[0199] Table 4 Extraction ability of extractant B for each metal ion in the blend solution

[0200]

[0201] Note: “—” indicates that the value is lower than the detection limit of ICP-OES.

[0202] As can be seen from Table 4, extractant B has excellent extraction selectivity for molybdenum and tungsten, and basically does not extract other coexisting metal ions tin, zinc, and aluminum. The main reason is attributed to the unique molecular structure of the prepared extractant B.

[0203] It can be seen that the extractant B prepared by the present invention achieves a qualitative change in the chelating effect of molybdenum and tungsten ions by designing the type of derivatized functional groups, the number of functional groups, the length of the functional group chain segment, the molecular main chain structure and its steric hindrance, and the synergy of the above series of variables, thereby achieving efficient and selective extraction of molybdenum and tungsten, and avoiding interference from impurities such as rhenium, tin, zinc, and aluminum.

[0204] It should be noted that: the patent with publication number CN118480034A provides a degradable and environmentally friendly extractant and a method for separating molybdenum, tungsten and rhenium from industrial wastewater. The extractant used in this method uses a straight-chain diamide as a molecular skeleton, and this application uses a straight-chain long-chain / cyclic aliphatic diamine as a molecular skeleton. It is not difficult to see that compared with the extractant used in "Degradable and environmentally friendly extractant and a method for separating molybdenum, tungsten and rhenium from industrial wastewater", the end of the molecular structure of the extractant prepared in this application has a "high-density" hydroxyl structure, that is, 1 mol of the extractant has 6 mol of hydroxyl groups, which is more conducive to regulating the spatial arrangement of the entire molecular chain segment, so that the extractant molecular skeleton has a good spatial dimensional anisotropic expansion effect, presenting a specific spatial structure, and providing a prerequisite for the subsequent selective extraction of tungsten and molybdenum. In addition, the selective extraction of tungsten and molybdenum in the extractant used in "Degradable and Environmentally Friendly Extractant and Method for Separating Molybdenum, Tungsten and Rhenium from Industrial Waste Water" is also due to the anion structure in the structure - sulfonated sulfate; while the selective extraction of tungsten and molybdenum in the extractant prepared in this application is also due to the anion structure in the structure - bromide ion.

[0205] In summary, the extractant provided by the present invention and the method for separating tungsten and molybdenum therefrom, the extractant is derivatized with quaternary ammonium salt by aliphatic chain primary alcohol, and the selective extraction of target metal by the extractant is regulated by changing the number of aliphatic chain primary alcohols and the length of its chain segments and the position of functional groups, and the diquaternary ammonium salt fragment structure ensures the efficient extraction of target metal. The quaternary ammonium salt is linked by a straight chain or annular aliphatic chain segment, and can be miscible with various solvents to the greatest extent, can meet various application scenarios, and broaden the working environment of the extractant. In addition, the nitrogen atom in the molecular structure of the extractant is derivatized with aliphatic primary alcohols of a specific number, and on the basis of improving the selective extraction of molybdenum and tungsten, it also has good chemical stability and is difficult to be oxidized by conventional oxidants. The annular aliphatic chain segments in the extractant are not in a plane, presenting spatial dislocation, ensuring the spatial extension range of the terminal diquaternary ammonium salt, and can achieve effective complexation with tungsten and molybdenum ions; the long-chain aliphatic chain segments are arranged in a zigzag alternating manner, and as the carbon chain grows, the accumulation of space is avoided, and the active sites can also be effectively complexed with tungsten and molybdenum ions. By changing the type of derivatized functional groups, the number of functional groups, the length of the functional group chain segments, the molecular main chain structure and its steric hindrance, the synergy of the above series of variables achieves a qualitative change in the chelating effect of molybdenum and tungsten ions, thereby achieving efficient and selective extraction of molybdenum and tungsten.

[0206] 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 extractant includes extractant A; the structural formula of the extractant A is: ； Among them, 6≤n≤12.

2. An extractant, characterized in that The extractant further comprises an extractant B; the structural formula of the extractant B is: ； Among them, 2≤n≤4.

3. A method for preparing an extractant, characterized in that: The steps include: S1. Add N-di-2-hydroxyethylamine and dibromododecane to anhydrous ethanol in a first predetermined ratio, and then add sodium hydroxide to obtain a mixed solution 1, and then place the mixed solution 1 at a predetermined temperature for reaction; The first predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to dibromododecane is 6-8:1; In the mixed solution 1, the concentration of N-di-2-hydroxyethylamine is 0.3-0.8 mol / L, the concentration of dibromododecane is 0.05-0.1 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L; The reaction temperature is 50-100°C and the reaction time is 24-72h; S2, performing distillation-extraction treatment on the mixed solution after the reaction to obtain an oily intermediate product, namely, extractant A-mid; S3, adding the extractant A-mid and bromoethanol to anhydrous ethanol in a second predetermined ratio to prepare a second mixed solution, and then placing the second mixed solution at a predetermined temperature for reaction; The second predetermined ratio is: the molar ratio of the extractant A-mid to bromoethanol is 1:3-5; The reaction temperature is 50-100°C and the reaction time is 24-48 hours; S4, the mixed solution after the reaction is subjected to distillation-extraction treatment to obtain the target product, extractant A; the synthesis formula of the extractant A is: 。 4. A method for preparing an extractant, characterized in that: The following steps are also included: Sa. Add N-di-2-hydroxyethylamine and 1,4-bromocyclohexane to anhydrous ethanol in a third predetermined ratio, and then add sodium hydroxide to obtain a mixed solution three; and then place the mixed solution three at a predetermined temperature for reaction; The third predetermined ratio is: the molar ratio of N-di-2-hydroxyethylamine to 1,4-bromocyclohexane is 5-10:1; In the mixed solution three, the concentration of N-di-2-hydroxyethylamine is 0.25-1 mol / L, the concentration of 1,4-bromocyclohexane is 0.05-0.1 mol / L, and the concentration of sodium hydroxide is 0.1-0.5 mol / L; The reaction temperature is 50-100°C and the reaction time is 24-72h; Sb, distilling and extracting the mixed solution after the reaction to obtain an oily intermediate product, namely, extractant B-mid; Sc, adding the extractant B-mid and bromoethanol to anhydrous ethanol-cyclohexane solution in a fourth predetermined ratio to prepare a mixed solution four, and then placing the mixed solution four at a predetermined temperature for reaction; The fourth predetermined ratio is: the volume ratio of anhydrous ethanol to cyclohexane in the anhydrous ethanol-cyclohexane solution is 4-9:1, and the molar ratio of the extractant B-mid to bromoethanol is 1:3-5; The reaction temperature is 50-100°C and the reaction time is 24-48 hours; Sd, and further distilling and extracting the mixed solution 4 after the reaction to obtain the target product, extractant B; The synthetic formula of the extractant B is: 。 5. An application of an extractant, characterized in that: The method of separating molybdenum and tungsten from industrial wastewater by using the extractant described in any one of claims 1 to 2 specifically comprises the following steps: SA, mixing the extractant with sulfonated kerosene, dissolving by ultrasonication, and obtaining a diluent; SB, adjust the pH value of industrial wastewater solutions containing molybdenum and tungsten to acidic; SC. Add the diluent in step SA to the solution obtained in step SB to extract molybdenum and tungsten in the industrial wastewater solution.

6. The use of the extractant according to claim 5, characterized in that: In the industrial wastewater containing molybdenum and tungsten, molybdenum is in the form of HMoO4 - 、H2MoO4、MoO2 2+ exists in one or more forms.

7. The use of the extractant according to claim 5, characterized in that: In the industrial wastewater containing molybdenum and tungsten, tungsten is in the form of HWO4 - 、H2WO4、WO2 2+ One or more forms of exist.

8. The use of the extractant according to claim 5, characterized in that: In the diluent, the volume ratio of the extractant to sulfonated kerosene is 1:10-100.

9. The use of the extractant according to claim 5, characterized in that: The pH value in step SB is in the range of 1 to 6.

10. The use of the extractant according to claim 5, characterized in that: The industrial wastewater containing molybdenum and tungsten includes one or more of ore solution, catalyst waste liquid, metallurgical waste liquid, and electronic waste leaching solution.

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