An extractant, its preparation method and application

Abstract

The application provides an extractant and a preparation method and application thereof, and relates to the technical field of extraction separation. The extractant provided by the application introduces phosphonic acid groups (O=P-OH), amino groups and carboxyl groups, the phosphonic acid groups and the carboxyl groups have synergistic coordination effects, can form a more stable strong chelating ring, improve the combination capacity with metal ions, and improve the extraction capacity and efficiency; meanwhile, the functional groups present a symmetrical structure in space, which is more conducive to capturing and grabbing metal ions. The extractant has high extraction efficiency and selectivity for metal ions (Fe 3+ , Al 3+ , Cu 2+ , Zn 2+ ), and is stable in structure; the efficiency of single-stage simultaneous extraction of iron and aluminum and copper and zinc is high, and a multi-stage process is not needed; the extractant has a wide applicable acidity range; the extractant is in a solid state, is more convenient to store and transport, and does not need a diluent or a phase regulator; the extractant is easy to separate and regenerate, and has good cycle stability. The extractant is suitable for iron and aluminum purification in wet-process phosphoric acid and copper and zinc recovery in electroplating wastewater.

Description

Technical Field

[0001] This invention relates to the field of extraction and separation technology, and in particular to an extractant, its preparation method, and its application. Background Technology

[0002] In the fields of hydrometallurgy, wet phosphoric acid purification, and industrial wastewater treatment, the efficient separation and selective removal of metal ions are core technologies. Extraction methods, due to their advantages such as simple process, good selectivity, and ease of continuous and automated control, have become the mainstream technology for metal separation and purification. As the core functional component of the extraction system, the structure and performance of the extractant directly determine the separation efficiency, operating costs, and environmental friendliness.

[0003] Currently, organophosphorus compounds are the most widely used metal extractants in industry, such as bis(2-ethylhexyl) phosphate (P204), 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (P507), and bis(2,4,4-trimethylpentyl)phosphonic acid (Cyanex 272 or C272). While these extractants possess certain extraction capabilities in specific systems, they still suffer from several inherent drawbacks: they require large quantities of volatile organic solvents as diluents, are flammable, explosive, and highly toxic; the extraction process is prone to emulsification, slow phase separation, and severe entrainment; and they are also susceptible to metal ions (such as Fe)... 3+ Al 3+ (etc.) has a low single-stage extraction rate; it is not suitable for efficient separation of highly acidic (such as wet phosphoric acid) and complex systems with high impurities. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide an extractant, its preparation method, and its application. The extractant provided by the present invention requires no diluent or phase modifier, and is effective against metal ions (Fe... 3+ Al 3+ Cu 2+ Zn 2+ It has high extraction efficiency and selectivity, a wide applicable acidity range, and is suitable for the purification of phosphoric acid solutions.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an extractant having the structure shown in Formula I: Formula I, In Formula I, R1 is a phenylphosphino acid group, a phosphino acid group, or a phosphonite group, and R2 is any one of the following groups: , , , , , .

[0006] This invention provides a method for preparing the extractant described in the above technical solution, comprising the following steps: An aqueous solution of an inorganic acid containing an amino group is mixed with a phosphoric acid compound to obtain a mixture; wherein the phosphoric acid compound is phenylphosphinoic acid, phosphinoic acid, or phosphonic acid, and the amino group containing the amino group is iminodiacetic acid, diethyl iminodiacetic acid, aspartic acid, glycine, alanine, or glutamic acid. The mixture is mixed with terephthalaldehyde to carry out an addition reaction. The resulting reaction solution is then subjected to dehydration, washing, and drying to obtain the extractant.

[0007] Preferably, the molar ratio of the amino-containing compound to the phosphoric acid compound is 1:1 to 1:2; the mixing temperature of the aqueous solution of the amino-containing compound and the phosphoric acid compound is 90 to 120°C, and the mixing time is 1 to 3 hours.

[0008] Preferably, the molar ratio of the phosphoric acid compound to terephthalaldehyde is 1:1 to 2.5:1; the addition reaction is carried out at a temperature of 90 to 120°C for 5 to 8 hours.

[0009] This invention provides the application of the extractant described in the above technical solutions or the extractant prepared by the above technical solutions in the extraction of metal ions, wherein the metal ions include Fe. 3+ Al 3+ Cu 2+ and Zn 2+ One or more of them.

[0010] Preferably, the metal ions are derived from wet phosphoric acid or electroplating wastewater.

[0011] This invention provides a method for purifying iron and aluminum from wet-process phosphoric acid or for purifying copper and zinc from electroplating wastewater, comprising the following steps: The solution to be purified is mixed with an extractant for extraction, followed by solid-liquid separation to obtain a raffinate and an extract phase enriched with metal ions. The solution to be purified is wet-process phosphoric acid or electroplating wastewater, wherein the wet-process phosphoric acid contains Fe. 3+ And Al 3+ The electroplating wastewater contains Cu 2+ and Zn 2+ The extractant is the extractant described in the above technical solution or the extractant prepared by the preparation method described in the above technical solution.

[0012] Preferably, the concentration of the extractant in the mixture obtained by mixing the solution to be purified with the extractant is 0.02~0.06 mol / L; the extraction temperature is 25~50℃ and the extraction time is 30~90 min.

[0013] Preferably, after obtaining the metal ion-enriched extractant phase, the method further includes mixing the metal ion-enriched extractant phase with a back-extraction agent for back-extraction to obtain a metal ion-enriched aqueous phase and a regenerated extractant; the back-extraction agent is an acid solution, which is one or more of oxalic acid solution, hydrochloric acid, sulfuric acid and nitric acid, and the concentration of the acid solution is 0.5~2 mol / L.

[0014] Preferably, the ratio of the back-extraction agent to the metal ion enrichment extraction phase is (1~5) mL:1 g; the back-extraction temperature is 25~40℃ and the time is 15~60 min.

[0015] This invention provides an extractant having the structure shown in Formula I. The extractant provided by this invention has a multifunctional complex structure, incorporating functional groups such as phosphonic acid groups (O=P-OH), amino groups, and carboxyl groups. The phosphonic acid group and the carboxyl group exhibit a significant synergistic coordination effect during extraction: the P=O bond in the phosphonic acid group provides a strong coordination site, while the carboxyl group provides a complementary coordination mode and charge balancing ability, together forming a multidentate chelating environment. This results in a metal complex with significantly higher stability than that of single-functional-group extractants, improving extraction capacity and efficiency. The amino group, as the third coordinating active group, provides a lone pair of electrons with its nitrogen atom, forming an N-O multidentate coordination system with the phosphonic acid group and the carboxyl group, enhancing the chelation stability and selectivity of metal ions. The extractant exhibits selectivity, and the weak basicity of the amino group can regulate the overall acidity response range of the molecule, buffering local charge changes and broadening the applicable pH window of the extractant. Furthermore, the amino group assists the rigid framework in maintaining the pre-organized configuration of coordinating atoms through intramolecular hydrogen bonding, reducing coordination entropy increase and improving extraction kinetics. Moreover, the extractant provided by this invention possesses a rigid spatially symmetrical framework, ensuring that all coordinating atoms are in a pre-organized spatial state. When in contact with metal ions, optimal coordination geometry matching can be achieved without consuming a large amount of energy for conformational adjustment, significantly reducing entropy increase in the coordination process. This results in faster extraction reaction kinetics and more favorable thermodynamics, thereby further improving extraction efficiency and capacity. Compared with existing technologies, this invention has the following beneficial effects: The extractant provided by this invention has a multifunctional group complex synergistic effect and a spatially symmetrical structure, which is effective for metal ions (Fe). 3+ Al 3+ Cu 2+ Zn 2+ It has high extraction efficiency and selectivity, and its structure is stable; The extractant provided by this invention has high efficiency in single-stage simultaneous extraction of iron and aluminum, as well as simultaneous extraction of copper and zinc, without the need for multi-stage processes. It offers high operational flexibility and mild conditions. Emulsification does not occur during extraction, and separation is easy (simply by filtration). Furthermore, it has a wide applicable acidity range (pH 0.3~6) and can be used to purify metal ions in wet-process phosphoric acid (such as the purification of iron and aluminum in wet-process phosphoric acid). The extractant provided by this invention is in solid form, which makes it more stable, more convenient to store and transport, and requires no diluent or phase modifier. It is easy to use and low in cost. The extractant provided by this invention is easy to separate, easy to regenerate, and has good cycle stability.

[0016] This invention provides a method for preparing the extractant described in the above technical solution. The preparation method provided by this invention is free of volatile organic solvents, is green and safe, has a simple process flow, readily available raw materials, mild reaction conditions, and is easy to scale up industrially.

[0017] The results of the examples show that when the extractant provided by the present invention is used for the purification of iron and aluminum in wet-process phosphoric acid, Fe 3+ The extraction rate was 85.4%–97.1%, Al 3+ The extraction rate is 20.1~31.5%, used for copper and zinc recovery from electroplating wastewater. 2+ The extraction rate was 84.3%~98.3% for Zn. 2+ The extraction rate was 88.2%–96.7%, and it exhibited good selectivity. Attached Figure Description

[0018] Figure 1 The infrared spectrum of the extractant prepared for the example is shown. Detailed Implementation

[0019] This invention provides an extractant having the structure shown in Formula I: Formula I, In Formula I, R1 is a phenylphosphino acid group, a phosphino acid group, or a phosphonite group, and R2 is any one of the following groups (the following groups are not included in the formula). (Indicates the connection site) , , , , , .

[0020] With R1 being phenylphosphine group and R2 being For example, the structure of the extractant is as follows (chemical name: 1,4-bis[α-(N,N'-dicarboxymethyl)phenylphosphonic acid]benzene): .

[0021] With R1 as a phosphonic acid group and R2 as For example, the structure of the extractant is as follows: .

[0022] With R1 as a phosphonate group and R2 as For example, the structure of the extractant is as follows: .

[0023] The multifunctional group composite structure extractant provided by this invention introduces functional groups such as phosphonic acid group (O=P-OH), amino group, and carboxyl group. The phosphonic acid group and carboxyl group have a synergistic coordination effect, which can form a more stable strong chelate ring, improve the binding ability with metal ions, and improve the extraction capacity and efficiency. At the same time, the extractant provided by this invention has a spatially symmetrical structure, and the functional groups exhibit a symmetrical structure in space, which is more conducive to capturing and binding metal ions.

[0024] When R2 is In addition, ester groups are introduced into the structure of the extractant. The ester group, phosphonic acid group and amino group work together. The phosphonic acid group and amino group provide the main coordination sites, while the ester group regulates the molecular polarity and spatial configuration, improves the utilization rate of active sites and the stability of organic phase, thereby improving the extraction efficiency and selectivity of the extractant.

[0025] In this embodiment of the invention, the extractant is referred to as aminophosphonic acid extractant.

[0026] This invention provides a method for preparing the extractant described in the above technical solution, comprising the following steps: An aqueous solution of an inorganic acid containing an amino group is mixed with a phosphoric acid compound to obtain a mixture; wherein the phosphoric acid compound is phenylphosphinoic acid, phosphinoic acid, or phosphonic acid, and the amino group containing the amino group is iminodiacetic acid, diethyl iminodiacetic acid, aspartic acid, glycine, alanine, or glutamic acid. The mixture is mixed with terephthalaldehyde to carry out an addition reaction. The resulting reaction solution is then subjected to dehydration, washing, and drying to obtain the extractant.

[0027] Unless otherwise specified, all raw materials involved in this invention are commercially available products well known in the art.

[0028] This invention involves mixing an aqueous solution of an inorganic acid containing an amino group with a phosphoric acid compound to obtain a mixed solution.

[0029] In this invention, the amino-containing compound is iminodiacetic acid, diethyl iminodiacetic acid, aspartic acid, glycine, alanine, or glutamic acid. In this invention, the aqueous solution of the amino-containing compound in an inorganic acid is a mixed solution of the amino-containing compound, an inorganic acid, and water; the inorganic acid is preferably one or more of hydrochloric acid, acetic acid, sulfuric acid, nitric acid, and phosphoric acid; the molar ratio of the amino-containing compound to the inorganic acid is preferably 1:3 to 1:1, and can be 1:1, 1:1.5, 1:2, or 1:3; the volume ratio of the amino-containing compound to water is preferably 0.2 mol:(80~160) mL, and can be 0.2 mol:100 mL. In an embodiment of this invention, the method for preparing the aqueous solution of the amino-containing compound in an inorganic acid is as follows: the amino-containing compound, the inorganic acid, and water are added sequentially to a reaction vessel, and the mixture is heated until the solution is clear and transparent; the heating temperature is preferably 90~120℃, and can be 90, 100, 110, or 120℃.

[0030] In this invention, the phosphoric acid compound is phenylphosphine, phosphinolic acid, or phosphonite. The molar ratio of the amino-containing compound to the phosphoric acid compound is preferably 1:1 to 1:2, and can be 1:1.05, 1:1.25, 1:1.5, or 1:2. Preferably, the phosphoric acid compound is added to an aqueous solution of the amino-containing compound in an inorganic acid solution. In this invention, the mixing temperature of the aqueous solution of the amino-containing compound in an inorganic acid solution and the phosphoric acid compound is preferably 90 to 120°C, and can be 90, 100, 110, or 120°C. The mixing time is preferably 1 to 3 hours, and can be 1, 2, or 3 hours. This invention controls the temperature at 90~120℃ and the time at 1~3h, which helps to ensure that the raw materials are fully dissolved and homogeneously mixed. The amino-containing compound and the phosphonic acid compound form a pre-activated system under acidic conditions and are heated. Homogeneous dispersion is achieved through acid-base interaction and hydrogen bonding, providing reaction sites for the subsequent condensation grafting reaction. If the temperature is too low, it will lead to uneven dissolution. If the temperature is too high, it will reduce the efficiency of subsequent functional group grafting. If the time is insufficient, the mixing and pre-activation will be inadequate.

[0031] After obtaining the mixture, the present invention mixes the mixture with terephthalaldehyde to carry out an addition reaction, and then sequentially removes the aqueous phase, washes and dries the resulting reaction solution to obtain the extractant.

[0032] In this invention, the molar ratio of the phosphate compound to terephthalaldehyde is preferably 1:1 to 2.5:1, and can be 1.5:1, 2:1, or 2.1:1. In this invention, the terephthalaldehyde is preferably added in the form of a mixture of terephthalaldehyde and water, and the addition method can be dropwise. The concentration of the terephthalaldehyde and water mixture can be 1 to 4 mol / L.

[0033] In this invention, the preferred temperature for the addition reaction is 90-120°C, which can be 90, 100, 110, or 120°C, and the preferred time is 5-8 hours, which can be 5, 6, 7, or 8 hours. This invention controls the temperature of the addition reaction within the range of 90-120°C, which is the optimal temperature range for efficient grafting of multifunctional groups, thus helping to avoid product structural defects and improve extraction performance.

[0034] In this invention, the washing reagent used is preferably an inorganic acid solution, which is preferably a sulfuric acid solution or a hydrochloric acid solution, and the concentration of the sulfuric acid solution or hydrochloric acid solution is preferably 1 mol / L; after washing, rotary evaporation is preferably performed, followed by drying.

[0035] The preparation method provided by this invention has a simple process flow, few steps, readily available raw materials, mild reaction conditions, no need for volatile organic solvents, lower energy consumption, is green and environmentally friendly, simple post-processing, high yield (70.6~85.6%), and is easy to industrialize.

[0036] This invention provides the application of the extractant described in the above technical solutions or the extractant prepared by the above technical solutions in the extraction of metal ions, wherein the metal ions include Fe. 3+ Al 3+ Cu 2+ and Zn 2+ One or more of them.

[0037] In this invention, the metal ions preferably come from wet phosphoric acid or electroplating wastewater.

[0038] The extractant provided by this invention is effective for Fe 3+ Al 3+ Cu 2+ Zn 2+ It features high extraction efficiency and selectivity, easy back-extraction and regeneration, and recyclability. It is suitable for the purification of iron and aluminum from wet-process phosphoric acid and the recovery of copper and zinc from electroplating wastewater. It also has a wide applicable acidity range (suitable for purification of phosphoric acid solutions with concentrations up to 5 mol / L) and stable structure (exhibiting good extraction effects at temperatures ranging from 25 to 50°C). Furthermore, it requires no diluent or phase modifier, making it simple to use and low in cost. In addition, the extractant provided by this invention is in solid (powder) form, resulting in greater stability and easier storage and transportation.

[0039] This invention provides a method for purifying iron and aluminum from wet-process phosphoric acid or for purifying copper and zinc from electroplating wastewater, comprising the following steps: The solution to be purified is mixed with an extractant for extraction, followed by solid-liquid separation to obtain a raffinate and an extract phase enriched with metal ions. The solution to be purified is wet-process phosphoric acid or electroplating wastewater, wherein the wet-process phosphoric acid contains Fe. 3+ And Al 3+The electroplating wastewater contains Cu 2+ and Zn 2+ The extractant is the extractant described in the above technical solution or the extractant prepared by the preparation method described in the above technical solution.

[0040] In this invention, the concentration of phosphoric acid in the wet-process phosphoric acid is preferably 3-5 mol / L, and can be 3, 3.5, 4, 4.5, or 5 mol / L. 3+ The preferred concentration is 1.5~2.5 g / L, and can be 1.5, 1.7, 2, 2.1 or 2.2 g / L. Al 3+ The preferred concentration is 2~2.5 g / L, and can be 2, 2.1, 2.2, 2.3, 2.4 or 2.5 g / L; the Cu in the electroplating wastewater 2+ The preferred concentration is 0.1~0.5 g / L, and can be 0.1, 0.2, 0.3, 0.4 or 0.5 g / L, Zn 2+ The concentration is preferably 0.1~0.4 g / L, and can be 0.1, 0.15, 0.2, 0.3 or 0.4 g / L.

[0041] In this invention, the extractant is preferably added to the solution to be purified. In this invention, the concentration of the extractant in the mixture obtained by mixing the solution to be purified and the extractant is preferably 0.02~0.06 mol / L, and can be 0.02, 0.03, 0.04, 0.05, or 0.06 mol / L; the extraction temperature is preferably 25~50℃, and can be 25, 30, 35, 40, 45, or 50℃; the extraction time is preferably 30~90 min, and can be 40, 45, 50, 60, 70, 80, or 90 min; the extraction is preferably carried out under stirring conditions.

[0042] This invention does not impose any particular requirements on the solid-liquid separation method; any solid-liquid separation method well-known to those skilled in the art can be used. After solid-liquid separation, a raffinate and a solid extract phase are obtained. The solid extract phase includes an extractant and enriched metal ions. When the solution to be purified is wet-process phosphoric acid, the enriched metal ion is Fe. 3+ And Al 3+ When the solution to be purified is electroplating wastewater, the enriched metal ions are Cu. 2+ and Zn 2+ .

[0043] In this invention, after obtaining the metal ion-enriched extractant phase, the process preferably further includes mixing the metal ion-enriched extractant phase with a back-extraction agent for back-extraction to obtain a metal ion-enriched aqueous phase and a regenerated extractant. In this invention, the back-extraction agent is preferably an acid solution, preferably one or more of oxalic acid solution, hydrochloric acid, sulfuric acid, and nitric acid. The concentration of the acid solution is preferably 0.5~2 mol / L, and can be 1, 1.2, 1.5, 1.6, or 2 mol / L. The ratio of the back-extraction agent to the metal ion-enriched extractant phase is preferably (1~5) mL:1 g, and can be 2 mL:1 g or 3 mL:1 g. In this invention, the back-extraction (also known as acid washing) temperature is preferably 25~40℃, and can be 25, 30, 35, or 40℃. The time is preferably 15~60 min, and can be 20, 30, 40, 45, 50, or 60 min. In this invention, the regenerated extractant can be recycled.

[0044] The extractant provided by this invention can be used to purify iron and aluminum in wet-process phosphoric acid or copper and zinc in electroplating wastewater. It offers high efficiency for single-stage simultaneous extraction of iron and aluminum, as well as copper and zinc, eliminating the need for multi-stage processes. The extractant is easy to separate, regenerate, and exhibits good cycle stability. The extractant provided by this invention shows promising application prospects in phosphoric acid purification and metal ion purification of industrial wastewater.

[0045] Extraction rate (E) can intuitively show the extraction capacity of the extractant, while back-extraction rate (S) can reflect the regeneration capacity of the extractant. The concentration of metal ions in the initial aqueous phase, raffinate, and back-extraction raffinate (i.e., the aqueous phase enriched with metal ions) is determined by ICP-OES, and the extraction rate (E) and back-extraction rate (S) are calculated by formulas (1) to (2), respectively: Formula (1), Formula (2), In formulas (1) to (2), C0, C1, and C2 represent the metal ion concentrations in the initial aqueous phase, raffinate, and back-raffinate, respectively.

[0046] To further illustrate the present invention, the extractant, its preparation method, and its application provided by the present invention are described in detail below with reference to examples, but these should not be construed as limiting the scope of protection of the present invention.

[0047] Example 1 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.3 mol sulfuric acid (AR, 95~98% mass fraction), and 100 mL water in sequence, mix and heat to 90 °C to obtain a clear and transparent solution; (2) Add 0.21 mol of phenylphosphine to the clear and transparent solution in step (1) and mix at a constant temperature of 90°C for 2 hours; (3) Slowly add a mixture of 0.1 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 90°C for 6 h; (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L sulfuric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 77.6%.

[0048] Example 2 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.2 mol sulfuric acid (AR, 95~98% mass fraction), and 100 mL water in sequence, mix and heat to 100 °C to obtain a clear and transparent solution; (2) Add 0.3 mol of phenylphosphine to the clear and transparent solution in step (1) and mix at a constant temperature of 100°C for 3 h; (3) Slowly add a mixture of 0.2 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 100 °C for 6 h. (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L sulfuric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 80.1%.

[0049] Example 3 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.4 mol hydrochloric acid (AR, 36~38% mass fraction) and 100 mL water in sequence, mix and heat to 110 °C to obtain a clear and transparent solution; (2) Add 0.3 mol of phenylphosphine to the clear and transparent solution in step (1) and mix at a constant temperature of 110℃ for 2 h; (3) Slowly add a mixture of 0.15 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 110 °C for 8 h. (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L hydrochloric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 85.6%. Figure 1 The infrared spectrum of the obtained aminophosphonic acid extractant is shown.

[0050] Example 4 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.6 mol hydrochloric acid (AR, 36~38% mass fraction) and 100 mL water in sequence, mix and heat to 120 °C to obtain a clear and transparent solution; (2) Add 0.25 mol of phenylphosphine to the clear and transparent solution in step (1) and mix at a constant temperature of 120°C for 3 h; (3) Slowly add a mixture of 0.25 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 120 °C for 8 h. (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L hydrochloric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 72.5%.

[0051] Comparative Example 1 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.3 mol sulfuric acid (AR, 95~98% mass fraction) and 100 mL water in sequence, mix and heat to 140 °C to obtain a clear and transparent solution; (2) Add 0.21 mol of phenylphosphine to the clear and transparent solution in step (1) and mix at a constant temperature of 140℃ for 1 h; (3) Slowly add a mixture of 0.1 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 140 °C for 7 h; (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L sulfuric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 52.4%.

[0052] Comparative Example 2 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.3 mol sulfuric acid (AR, 95~98% mass fraction) and 100 mL water in sequence, mix and heat to 70 °C to obtain a clear and transparent solution; (2) Add 0.21 mol of phenylphosphine to the clear and transparent solution in step (1) and mix at a constant temperature of 70°C for 1 h; (3) Slowly add a mixture of 0.1 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 70°C for 7 h; (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L sulfuric acid solution. The gelatinous substance is then rotary evaporated and dried to obtain aminophosphonic acid extractant with a yield of 40.9%.

[0053] Example 5 The aminophosphonic acid extractant prepared in Example 3 was used to purify metal ions in a phosphoric acid solution. The method was as follows: the extractant was added to the phosphoric acid solution, thoroughly stirred and mixed, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was measured. 3+ The extraction rate was 97.1%, Al 3+ The extraction rate was 31.5%. After eluting the extract phase with oxalic acid solution (extraction agent), Fe-enriched phase was obtained. 3+ Al 3+ The solution and regenerated extractant, Fe 3+ The extraction rate was 98%, Al 3+ The back-extraction rate was 90%. After repeated extraction and regeneration recycling 8 times, Fe... 3+ The back-extraction rate decreased by 2.5%, Al 3 + The back-extraction rate decreased by 2.1%.

[0054] The phosphoric acid solution contained a phosphoric acid concentration of 5 mol / L, Fe 3+ The concentration was 2.2 g / L, Al 3+ The concentration of the extractant was 2.5 g / L, the extractant was 0.04 mol / L, the extraction reaction time was 70 min, the reaction temperature was 35 ℃, the back-extraction agent was 1.5 mol / L oxalic acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing temperature was 30 ℃, and the acid washing time was 50 min.

[0055] Example 6 The aminophosphonic acid extractant prepared in Example 3 was used to purify metal ions in electroplating wastewater. The method was as follows: the extractant was added to the electroplating wastewater, thoroughly stirred and mixed, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was measured. 2+ The extraction rate was 98.3%, Zn 2+ The extraction rate was 96.7%. After eluting the extract phase with hydrochloric acid solution (extraction agent), Cu-enriched phase was obtained. 2+ Zn 2+ The solution and the regenerated extractant, Cu 2+ The extraction rate was 97.8%, Zn 2+ The back-extraction rate was 96.1%.

[0056] Cu in electroplating wastewater 2+ The concentration is 0.3 g / L, Zn2+ The concentration of the extractant was 0.15 g / L, the extractant was 0.03 mol / L, the extraction reaction time was 70 min, the reaction temperature was 30 ℃, the back-extraction agent was 1.2 mol / L hydrochloric acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing time was 45 min, and the acid washing temperature was 25 ℃.

[0057] Example 7 The aminophosphonic acid extractant prepared in Example 3 was used to purify metal ions in a phosphoric acid solution. The method was as follows: the extractant was added to the phosphoric acid solution, thoroughly stirred and mixed, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was measured. 3+ The extraction rate was 90.2%, Al 3+ The extraction rate was 27.4%. After eluting the extract phase with oxalic acid solution (extraction agent), Fe-enriched phase was obtained. 3+ Al 3+ The solution and regenerated extractant, Fe 3+ The extraction rate was 96%, Al 3+ The back-extraction rate was 88%.

[0058] The phosphoric acid solution contained a phosphoric acid concentration of 5 mol / L, Fe 3+ The concentration was 2.1 g / L, Al 3+ The concentration of the extractant was 2.2 g / L, the extractant was 0.05 mol / L, the extraction reaction time was 60 min, the reaction temperature was 45 ℃, the back-extraction agent was 1.6 mol / L oxalic acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing temperature was 30 ℃, and the acid washing time was 45 min.

[0059] Example 8 The aminophosphonic acid extractant prepared in Example 3 was used to purify metal ions in a phosphoric acid solution. The method was as follows: the extractant was added to the phosphoric acid solution, stirred and mixed thoroughly, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was then measured. 3+ The extraction rate was 96%, Al 3+ The extraction rate was 24%, Mg 2+ The extraction rate was 3.1%, Ca 2+ The extraction rate was 2.6%, PO4 3- The loss rate is less than 1%.

[0060] The phosphoric acid solution contained a phosphoric acid concentration of 4 mol / L, Fe 3+ The concentration was 1.7 g / L, Al 3+ The concentration is 2 g / L, Mg 2+ The concentration was 1.0 g / L, Ca 2+The concentration of the extractant was 0.8 g / L; the extractant concentration was 0.03 mol / L; the extraction reaction time was 60 min; and the reaction temperature was 25 °C.

[0061] Example 9 The aminophosphonic acid extractant prepared in Example 3 was used to purify and refine metal ions in electroplating wastewater. The extractant was added to the electroplating wastewater and thoroughly stirred and mixed. After solid-liquid separation, the extract phase and raffinate were obtained, and the concentration of metal ions in the raffinate was measured. 2+ The extraction rate of Zn was 97%. 2+ The extraction rate was 95%, Ni + The extraction rate was 29.2%, Na + The extraction rate was 1.1%, Ca 2+ The extraction rate was 1.4%. Cu in electroplating wastewater 2+ The concentration is 0.2 g / L, Zn 2+ The concentration of Ni is 0.1 g / L. + The concentration was 0.05 g / L, Na + The concentration was 4.0 g / L, Ca 2+ The concentration of the extractant was 0.3 g / L, the extractant was 0.02 mol / L, the extraction reaction time was 60 min, and the reaction temperature was 25℃.

[0062] Comparative Example 3 (1) Using No. 260 solvent oil as a diluent, solutions of D2EHPA, naphthenic acid, and Cyanex 272 with a concentration of 0.5 mol / L were prepared as the organic phase; the organic phase was then mixed with a phosphoric acid solution (phosphoric acid concentration of 4 mol / L, Fe...) 3+ The concentration was 1.8 g / L, Al 3+ The solution (with a concentration of 2.1 g / L) was mixed at a volume ratio of 5:1 and extracted for 45 min at a temperature of 25 °C. After extraction, the solution was centrifuged and phase-separated to obtain Fe-enriched solution. 3+ Al 3+ The organic phase and raffinate were analyzed, and the Fe content in the raffinate was determined. 3+ Al 3+ The concentration was used to calculate the extraction rate, and the results are shown in Table 1. (2) As a comparison, the aminophosphonic acid extractant prepared in Example 3 was added to a phosphoric acid solution (extractant 0.05 mol / L), mixed thoroughly, and allowed to precipitate. The extraction time was 45 min, and the extraction temperature was 25 °C. After solid-liquid separation, the extract phase and raffinate were obtained, and the Fe in the raffinate was determined. 3+ Al 3+ The concentration was used to calculate the extraction rate, and the results are shown in Table 1.

[0063] Table 1. Effects of different extractants on Fe in phosphoric acid solution 3+ Al 3+ extraction rate

[0064] Example 10 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol diethyl iminodiacetate, 0.3 mol hydrochloric acid (AR, 36~38% mass fraction), and 100 mL water in sequence, mix and heat to 100 °C to obtain a clear and transparent solution; (2) Add 0.21 mol of phosphonic acid to the clear and transparent solution in step (1) and react at a constant temperature of 100℃ for 2 h; (3) Slowly add a mixture of 0.1 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2), and continue the reaction at 100 °C for 6 h. (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L hydrochloric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 70.6%.

[0065] Example 11 (1) In a 500mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2mol aspartic acid, 0.3mol hydrochloric acid (AR, 36~38% mass fraction) and 100mL water in sequence, mix and heat to 100℃ to obtain a clear and transparent solution; (2) Add 0.21 mol of phosphonite to the clear and transparent solution in step (1) and react at a constant temperature of 100℃ for 2 hours; (3) Slowly add a mixture of 0.1 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2), and continue the reaction at 100 °C for 6 h. (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L hydrochloric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 75.4%.

[0066] Example 12 The aminophosphonic acid extractant prepared in Example 10 was used to purify metal ions in a phosphoric acid solution. The method was as follows: the extractant was added to the phosphoric acid solution, thoroughly stirred and mixed, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was measured. 3+ The extraction rate was 86.3%, Al 3+The extraction rate was 20.1%. After eluting the extract phase with oxalic acid solution (extraction agent), Fe-enriched phase was obtained. 3+ Al 3+ The solution and regenerated extractant, Fe 3+ The back-extraction rate was 89.2%, Al 3+ The back-extraction rate was 77.5%.

[0067] The phosphoric acid solution contained a phosphoric acid concentration of 4 mol / L, Fe 3+ The concentration was 1.7 g / L, Al 3+ The concentration of the extractant was 2.0 g / L, the extractant was 0.03 mol / L, the extraction reaction time was 60 min, the reaction temperature was 25 ℃, the back-extraction agent was 1.5 mol / L oxalic acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing temperature was 30 ℃, and the acid washing time was 45 min.

[0068] Example 13 The aminophosphonic acid extractant prepared in Example 11 above was used to purify and refine metal ions in electroplating wastewater. The method was as follows: the extractant was added to the electroplating wastewater solution, thoroughly stirred and mixed, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was measured. 2+ The extraction rate was 84.3%, Zn 2+ The extraction rate was 88.7%. After eluting the extract phase with hydrochloric acid solution (extraction agent), Cu-enriched phase was obtained. 2+ Zn 2+ The solution and the regenerated extractant, Cu 2+ The extraction rate was 85.9%, Zn 2+ The back-extraction rate was 89.4%.

[0069] Among them, electroplating wastewater Cu 2+ The concentration is 0.3 g / L, Zn 2+ The concentration of the extractant was 0.15 g / L, the extractant was 0.03 mol / L, the extraction reaction time was 70 min, the reaction temperature was 30 ℃, the back-extraction agent was 1.2 mol / L hydrochloric acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing time was 45 min, and the acid washing temperature was 25 ℃.

[0070] Example 14 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.3 mol sulfuric acid (AR, 95~98% mass fraction), and 100 mL water in sequence, mix and heat to 90 °C to obtain a clear and transparent solution; (2) Add 0.21 mol of phosphonic acid to the clear and transparent solution in step (1) and mix at a constant temperature of 90°C for 2 hours; (3) Slowly add a mixture of 0.1 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 90°C for 6 h; (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L sulfuric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 71.3%.

[0071] Example 15 (1) In a 500 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, add 0.2 mol iminodiacetic acid, 0.3 mol sulfuric acid (AR, 95~98% mass fraction), and 100 mL water in sequence, mix and heat to 90 °C to obtain a clear and transparent solution; (2) Add 0.21 mol of phosphonic acid to the clear and transparent solution in step (1) and mix at a constant temperature of 90°C for 2 hours; (3) Slowly add a mixture of 0.1 mol terephthalaldehyde and 100 mL water to the solution obtained in step (2) and keep the reaction at 90°C for 6 h; (4) After the reaction in step (3) is completed, the upper aqueous phase is removed, and the gelatinous substance after removing the aqueous phase is washed with 1 mol / L sulfuric acid solution. The gelatinous substance is then obtained by rotary evaporation and drying, with a yield of 74.8%.

[0072] Example 16 The aminophosphonic acid extractant prepared in Example 15 was used to purify metal ions in a phosphoric acid solution. The method was as follows: the extractant was added to the phosphoric acid solution, thoroughly stirred and mixed, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was measured. 3+ The extraction rate was 89.9%, Al 3+ The extraction rate was 24.6%. After eluting the extract phase with oxalic acid solution (extraction agent), Fe-enriched phase was obtained. 3+ Al 3+ The solution and regenerated extractant, Fe 3+ The back-extraction rate was 95.3%, Al 3+ The back-extraction rate was 87.1%.

[0073] The phosphoric acid solution contained a phosphoric acid concentration of 5 mol / L, Fe 3+ The concentration was 2.2 g / L, Al 3+ The concentration of the extractant was 2.5 g / L, the extractant was 0.04 mol / L, the extraction reaction time was 70 min, the reaction temperature was 35 ℃, the back-extraction agent was 1.5 mol / L oxalic acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing temperature was 30 ℃, and the acid washing time was 50 min.

[0074] Example 17 The aminophosphonic acid extractant prepared in Example 15 was used to purify metal ions in electroplating wastewater. The method was as follows: the extractant was added to the electroplating wastewater, thoroughly stirred and mixed, and after solid-liquid separation, the extract phase and raffinate were obtained. The concentration of metal ions in the raffinate was measured. 2+ The extraction rate was 90.7%, Zn 2+ The extraction rate was 88.2%. After eluting the extract phase with hydrochloric acid solution (extraction agent), Cu-enriched phase was obtained. 2+ Zn 2+ The solution and the regenerated extractant, Cu 2+ The extraction rate was 89.5%, Zn 2+ The back-extraction rate was 87.8%.

[0075] Cu in electroplating wastewater 2+ The concentration is 0.3 g / L, Zn 2+ The concentration of the extractant was 0.15 g / L, the extractant was 0.03 mol / L, the extraction reaction time was 70 min, the reaction temperature was 30 ℃, the back-extraction agent was 1.2 mol / L hydrochloric acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing time was 45 min, and the acid washing temperature was 25 ℃.

[0076] Example 18 The aminophosphonic acid extractant prepared in Example 14 was used to purify metal ions in a phosphoric acid solution. The method involved adding the extractant to the phosphoric acid solution, mixing thoroughly, and then separating the extract and raffinate. The concentration of metal ions in the raffinate was measured. (Fe...) 3+ The extraction rate was 85.4%, Al 3+ The extraction rate was 21.7%. After eluting the extract phase with oxalic acid solution (extraction agent), Fe-enriched phase was obtained. 3+ Al 3+ The solution and regenerated extractant, Fe 3+ The back-extraction rate was 90.6%, Al 3+ The back-extraction rate was 84.1%.

[0077] The phosphoric acid solution contained a phosphoric acid concentration of 5 mol / L, Fe 3+ The concentration was 2.2 g / L, Al 3+ The concentration of the extractant was 2.5 g / L, the extractant was 0.04 mol / L, the extraction reaction time was 70 min, the reaction temperature was 35 ℃, the back-extraction agent was 1.5 mol / L oxalic acid solution, added at a liquid-solid ratio of 3 mL: 1 g, the acid washing temperature was 30 ℃, and the acid washing time was 50 min.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An extractant, characterized in that, It has the structure shown in Equation I: Formula I, In Formula I, R1 is a phenylphosphino acid group, a phosphino acid group, or a phosphonite group, and R2 is any one of the following groups: 、 、 、 、 、 。 2. The method for preparing the extractant according to claim 1, characterized in that, Includes the following steps: An aqueous solution of an inorganic acid containing an amino group is mixed with a phosphoric acid compound to obtain a mixture; wherein the phosphoric acid compound is phenylphosphinoic acid, phosphinoic acid, or phosphonic acid, and the amino group containing the amino group is iminodiacetic acid, diethyl iminodiacetic acid, aspartic acid, glycine, alanine, or glutamic acid. The mixture is mixed with terephthalaldehyde to carry out an addition reaction. The resulting reaction solution is then subjected to dehydration, washing, and drying to obtain the extractant.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the amino-containing compound to the phosphoric acid compound is 1:1 to 1:2; the mixing temperature of the aqueous solution of the amino-containing compound and the phosphoric acid compound is 90 to 120°C, and the mixing time is 1 to 3 hours.

4. The preparation method according to claim 2, characterized in that, The molar ratio of the phosphoric acid compound to terephthalaldehyde is 1:1 to 2.5:1; the addition reaction is carried out at a temperature of 90 to 120°C for 5 to 8 hours.

5. The application of the extractant according to claim 1 or the extractant prepared by any one of claims 2 to 4 in the extraction of metal ions, wherein the metal ions include Fe. 3+ Al 3+ Cu 2+ and Zn 2+ One or more of them.

6. The application according to claim 5, characterized in that, The metal ions are derived from wet phosphoric acid or electroplating wastewater.

7. A method for purifying iron and aluminum from wet-process phosphoric acid or copper and zinc from electroplating wastewater, characterized in that, Includes the following steps: The solution to be purified is mixed with the extractant for extraction, and after solid-liquid separation, the raffinate and the extract phase enriched with metal ions are obtained. The solution to be purified is wet-process phosphoric acid or electroplating wastewater, wherein the wet-process phosphoric acid contains Fe. 3+ And Al 3+ The electroplating wastewater contains Cu 2+ and Zn 2+ The extractant is the extractant described in claim 1 or the extractant prepared by the preparation method described in any one of claims 2 to 4.

8. The method according to claim 7, characterized in that, The concentration of the extractant in the mixture obtained by mixing the solution to be purified with the extractant is 0.02~0.06mol / L; the extraction temperature is 25~50℃ and the extraction time is 30~90min.

9. The method according to claim 7, characterized in that, After obtaining the metal ion-enriched extractant phase, the process further includes mixing the metal ion-enriched extractant phase with a back-extraction agent for back-extraction to obtain a metal ion-enriched aqueous phase and a regenerated extractant; the back-extraction agent is an acid solution, which is one or more of oxalic acid solution, hydrochloric acid, sulfuric acid and nitric acid, and the concentration of the acid solution is 0.5~2 mol / L.

10. The method according to claim 9, characterized in that, The ratio of the back-extraction agent to the metal ion enrichment extraction phase is (1~5) mL:1 g; the back-extraction temperature is 25~40℃ and the time is 15~60 min.

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