Metal extractant microcapsule and preparation method thereof

Abstract

The invention relates to the field of metal extractant preparation, in particular to a metal extractant microcapsule and a preparation method thereof. The preparation method of the metal extraction agent microcapsule comprises the following preparation steps: (1) uniformly mixing ethyl acrylate, methacrylamide, 2-acrylamido-2-sodium methylpropanesulfonate, a cross-linking agent and an initiator, dropwise adding an emulsifier solution under a stirring condition, carrying out ultrasonic treatment, irradiating with ultraviolet light under the stirring condition for 10-20 minutes, washing with pure water, and separating to obtain a metal extraction agent microcapsule; drying to obtain a hollow microcapsule; and (2) vacuumizing the hollow microcapsule obtained in the step (1), adding a metal chelating agent, carrying out ultrasonic treatment for 5-10 hours, filtering, and washing to obtain the metal extractant microcapsule. The preparation process of the metal extractant microcapsule is simple and easy to operate, and the metal extractant microcapsule has a relatively good encapsulation efficiency on a metal chelating agent and has a relatively high removal effect on various metal ions.

Description

Technical Field

[0001] The invention relates to the field of metal extractant preparation, and in particular to a metal extractant microcapsule and a preparation method thereof. Background Art

[0002] Sputtering targets have a wide range of applications, mainly in the electronics and information industries, such as integrated circuits, information storage, liquid crystal displays, laser storage, electronic control devices, etc. They can also be used in the field of glass coating, and can also be used in industries such as wear-resistant materials, high-temperature corrosion resistance, and high-end decorative products. High chemical purity is the basis of the quality of sputtering targets, which has a direct impact on the composition and performance of the sputtering film. High-purity sputtering targets can significantly reduce the impact of impurities on the film layer, ensuring that the film layer has excellent physical and chemical properties. This requires that the metal solution used to make the sputtering target must also have a higher purity, so the metal solution needs to be purified to meet the requirements of the sputtering target.

[0003] In the purification process of metallic nickel solution, there are often many impurity ions, such as magnesium ions, copper ions, lead ions, manganese ions and iron ions. Generally, the impurity ions are removed by extraction, but the adsorption effect of different metal ions on different kinds of metal ions using common extractants in the extraction process is different, and the properties of the compounds formed by them and impurity ions are unstable, resulting in an increase in the number of extraction stages, which will make the process in the purification process more complicated and the production cost higher. Patent CN114045394 A discloses a method for separating copper from nickel chloride solution by extraction, in which the organic phase composed of Lix984 and sulfonated kerosene is continuously countercurrently extracted with nickel chloride solution in the extraction section, and the high copper organic phase loaded with nickel and cobalt after extraction is continuously countercurrently stripped with nickel-cobalt acid, and then continuously countercurrently stripped with copper acid, and reused in the extraction section. Although the copper removal effect in the invention is good and other impurities will not be introduced, the data on the impurity removal effect of manganese ions, chromium ions and magnesium ions are missing. Therefore, the extraction method used in the purification process of the metal solution used for the sputtering target still needs to be improved.

[0004] Based on the problems existing in the prior art, a metal extractant is developed, which has a good removal effect on different types of metal ions under the control of process conditions, which is of great significance both to scientific and technological development and actual industrial production. Summary of the invention

[0005] In order to solve the above-mentioned technical problems, the present invention provides a metal extractant microcapsule and a preparation method thereof. The preparation process of the metal extractant microcapsule is simple and easy to operate, has a good encapsulation rate for metal chelating agents, and has a high removal effect on various metal ions.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] The first aspect of the present invention provides a method for preparing metal extractant microcapsules, comprising the following preparation steps:

[0008] (1) Ethyl acrylate, methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid sodium salt, a crosslinking agent, and an initiator are uniformly mixed, an emulsifier solution is added dropwise under stirring, ultrasonication is performed, ultraviolet light is irradiated under stirring for 10-20 minutes, and then the hollow microcapsules are washed with pure water, separated, and dried to obtain hollow microcapsules;

[0009] (2) evacuating the hollow microcapsules obtained in step (1), adding a metal chelating agent, ultrasonically treating for 5-10 hours, filtering, and washing to obtain metal extractant microcapsules.

[0010] In some embodiments, the molar ratio of ethyl acrylate, methacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid sodium salt is 1:(1.5-2.5):(1.5-2).

[0011] Preferably, the molar ratio of ethyl acrylate, methacrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt is 1:2:1.75.

[0012] In some embodiments, the crosslinking agent includes 1,4-butanediol dimethacrylate and hexanediol dimethacrylate in a mass ratio of (25-30):1.

[0013] Preferably, the crosslinking agent comprises 1,4-butanediol dimethacrylate and hexanediol dimethacrylate in a mass ratio of 28:1.

[0014] In some embodiments, the amount of the cross-linking agent used is 15-20% of the total mass of ethyl acrylate, methacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid sodium salt.

[0015] Preferably, the usage amount of the cross-linking agent is 17% of the total mass of ethyl acrylate, methacrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt.

[0016] In some embodiments, the initiator is one or more of benzoin and its derivatives, acetophenones, aromatic ketones and acylphosphine oxides.

[0017] Preferably, the initiator is one or more of benzoin and its derivatives, acetophenones, and aromatic ketones.

[0018] In some embodiments, the emulsifier in the emulsifier solution is one or more of sodium ethylenediamine ethanesulfonate, sodium dodecyl diphenyl oxide disulfonate, and dodecylbenzene sulfonate; and the mass concentration of the emulsifier solution is 2-4.5 wt %.

[0019] Preferably, the emulsifier in the emulsifier solution is sodium ethylenediamine ethanesulfonate and sodium dodecyl diphenyl oxide disulfonate; and the mass concentration of the emulsifier solution is 3.5wt%.

[0020] In some embodiments, the emulsifier is used in an amount of 16-18% of the total mass of ethyl acrylate, methacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid sodium salt.

[0021] Preferably, the usage amount of the emulsifier is 17% of the total mass of ethyl acrylate, methacrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt.

[0022] In some embodiments, the mass ratio of the hollow microcapsules to the metal chelating agent in step (2) is (1.6-2.3):1.

[0023] Preferably, the mass ratio of the hollow microcapsules to the metal chelating agent in step (2) is 1.95:1.

[0024] In some embodiments, the metal chelator has the structural formula:

[0025]

[0026] In some embodiments, the method for preparing the metal chelator comprises the following preparation steps:

[0027] (1) dissolving dibutanolamine in anhydrous ethanol, adding carbon disulfide, reacting for 5-8 hours at 0-5° C. in a nitrogen atmosphere, adjusting the pH to neutral with an aqueous sodium hydroxide solution, and rotary evaporating to obtain sodium di(4-hydroxybutyl)dithiocarbamate;

[0028] (2) Add 4-[bis(β-chloroethyl)amino]benzaldehyde, sodium di(4-hydroxybutyl)dithiocarbamate obtained in step (1) and a catalyst to anhydrous ethanol, heat to reflux, remove the anhydrous ethanol under reduced pressure, add the obtained solid to pure water and stir, extract and combine the organic phases, dry the water in the organic phases, concentrate, let stand for 10-20 hours, separate, and obtain a metal chelating agent.

[0029] The second aspect of the present invention provides a metal extractant microcapsule prepared by the above-mentioned preparation method.

[0030] The invention uses ethyl acrylate, methacrylamide and 2-acrylamide-2-methylpropanesulfonic acid sodium salt as raw materials through process control, polymerizes them to form hollow microcapsules, and then loads a metal chelating agent in the hollow structure of the microcapsules through ultrasound to obtain metal extractant microcapsules with high encapsulation rate and high adsorption performance for various metal ions.

[0031] The applicant found that by selecting ethyl acrylate, methacrylamide, and 2-acrylamide-2-methylpropanesulfonic acid sodium salt as polymerization monomers, under the action of a photoinitiator and a specific emulsifier, by controlling the molar ratio of the polymerization monomers, the amount of the initiator and the emulsifier, metal extractant microcapsules with a high encapsulation rate for metal chelators can be successfully prepared. Under the condition of the same usage amount, the metal extractant microcapsules have a stronger adsorption capacity for different metal ions than metal chelators, which greatly reduces the production cost and improves the resource utilization rate. Among them, the acrylamide group in 2-acrylamide-2-methylpropanesulfonic acid sodium salt will accelerate the polymerization reaction; the two side methyl groups and sodium methyl sulfonate are combined behind the amino group, which can inhibit the hydrolysis and thermal degradation of the microcapsules; the sulfonated group can make the monomer show higher hydrophilicity and ionic characteristics under any pH. And the use of 2-acrylamide-2-methylpropanesulfonic acid sodium salt can also reduce the amount of emulsifier used and improve the water boundary resistance and thermal stability of the microcapsules.

[0032] The metal chelating agent used in the present invention has good dispersibility and solubility in various solvents, and forms a stable metal chelate by coordination chelation with heavy metal ions through nitrogen atoms, oxygen atoms and sulfur atoms. On the one hand, the metal chelating agent contains more hydroxyl groups, which can improve the performance of the metal chelating agent to a certain extent; on the other hand, the hydroxybutyl group in the structure can also increase the electron density on the surface of the chelating agent molecule and enhance the bonding strength between atoms in the chelating agent molecule. Moreover, the hydroxybutyl group in the chelating agent is symmetrically distributed, the symmetry of the chelating agent molecule is higher, and it is easier to combine with metal ions to form a symmetrical chelate ring, thereby improving the stability of the chelate.

[0033] In addition, in the process of loading the metal chelator in the hollow microcapsules, the metal chelator is more evenly dispersed in the hollow microcapsules by ultrasound, and the hydroxyl group in the metal chelator can form hydrogen bonds with the amide groups on the methacrylamide and 2-acrylamide-2-methylpropanesulfonic acid sodium salt in the wall material, making the interaction between the two more solid, thereby improving the adhesion of the metal chelator on the microcapsules; on the other hand, the hydroxyl group can also produce intermolecular electrostatic effects with the sulfonic acid groups on the 2-acrylamide-2-methylpropanesulfonic acid sodium salt, thereby further improving the stability of the metal extractant microcapsules. And the emulsifier in the present invention is preferably sodium ethylenediamine ethanesulfonate and sodium dodecyl diphenyl ether disulfonate, which, when used in combination, not only have good emulsification, water resistance, and good compatibility with the raw materials used in the system, but also can promote the formation of microcapsules, improve the uniformity and stability of the hollow microcapsules, and thus improve the stability of the metal extractant microcapsules.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The present invention uses process control to take ethyl acrylate, methacrylamide and 2-acrylamide-2-methylpropanesulfonic acid sodium salt as raw materials, polymerizes them to form hollow microcapsules, and then loads the metal chelating agent in the hollow structure of the microcapsules through ultrasound to obtain metal extractant microcapsules with high encapsulation rate and high adsorption performance for various metal ions, which greatly reduces production costs and improves resource utilization.

[0036] 2. In the process of loading the metal chelating agent into the hollow microcapsules of the present invention, the hydroxyl groups in the metal chelating agent can form hydrogen bonds with the amide groups on the methacrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt in the wall material, making the interaction between the two stronger, and can also generate intermolecular electrostatic effects with the sulfonic acid groups, so that the metal extractant microcapsules have better stability.

[0037] 3. The metal chelating agent used in the present invention has good dispersibility and solubility in a variety of solvents, can coordinate and chelate with heavy metal ions through nitrogen atoms, oxygen atoms, and sulfur atoms, has high adsorption performance, and the formed metal chelate is relatively stable. DETAILED DESCRIPTION

[0038] Now describe in detail various exemplary embodiments of the present invention, this detailed description should not be considered as limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing a particular embodiment, and are not used to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the range.

[0039] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. Various modifications and variations may be made to the specific embodiments of the present invention specification without departing from the scope or spirit of the present invention, which will be apparent to those skilled in the art. Other embodiments obtained from the present invention specification will be apparent to the technician. The present application specification and examples are exemplary only.

[0040] The words “include,” “including,” “have,” or “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0041] In Preparation Example 1 of the present invention, the catalyst used is potassium iodide, the extractant used is dichloromethane, and the initiator used is photosensitizer 651.

[0042] Preparation Example 1

[0043] The preparation method of the metal chelating agent used in the examples and comparative examples comprises the following preparation steps:

[0044] (1) Dissolve 1 mol of dibutanolamine in 500 mL of anhydrous ethanol, add 1.1 mol of carbon disulfide, react for 6 h at 0° C. in a nitrogen atmosphere, adjust the pH to neutral with a 2 mol / L sodium hydroxide aqueous solution, and perform rotary evaporation to obtain sodium di(4-hydroxybutyl)dithiocarbamate;

[0045] (2) 0.1 mol of 4-[bis(β-chloroethyl)amino]benzaldehyde, 0.235 mol of sodium di(4-hydroxybutyl)dithiocarbamate obtained in step (1) and 4.19 mmol of catalyst were added to 500 mL of anhydrous ethanol, and the mixture was heated under reflux at 90° C. for 25 h. The anhydrous ethanol was removed under reduced pressure, and the obtained solid was added to 500 mL of pure water and stirred. The mixture was then extracted three times with 250 mL of an extractant, and the organic phases were combined. 15 g of sodium sulfate was added to dry the water in the organic phase, and the mixture was concentrated to 50 mL. The mixture was allowed to stand for 20 h and filtered to obtain a metal chelating agent.

[0046] Preparation Example 2

[0047] Preparation steps of cross-linking agent:

[0048] 1,4-Butanediol dimethacrylate and hexanediol dimethacrylate in a mass ratio of 28:1 were mixed evenly to obtain a cross-linking agent.

[0049] Preparation Example 3

[0050] Preparation steps of cross-linking agent:

[0051] 1,4-Butanediol dimethacrylate and hexanediol dimethacrylate in a mass ratio of 20:1 were mixed evenly to obtain a cross-linking agent.

[0052] Preparation Example 4

[0053] Preparation steps of cross-linking agent:

[0054] 1,4-Butanediol dimethacrylate and hexanediol dimethacrylate in a mass ratio of 35:1 were mixed evenly to obtain a cross-linking agent.

[0055] Preparation Example 5

[0056] Preparation steps of emulsifier solution:

[0057] Take 2 g of sodium ethylenediamine ethanesulfonate and 1.5 g of sodium dodecyl diphenyl ether disulfonate and dissolve them in 100 g of pure water to obtain an emulsifier solution.

[0058] Preparation Example 6

[0059] Preparation steps of emulsifier solution:

[0060] 3.5 g of sodium dodecylbenzene sulfonate was dissolved in 100 g of pure water to obtain an emulsifier solution.

[0061] Example 1

[0062] A method for preparing metal extractant microcapsules comprises the following preparation steps:

[0063] (1) 0.1 mol of ethyl acrylate, 0.15 mol of methacrylamide, 0.15 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 8.57 g of a crosslinking agent, and 2.56 g of an initiator were uniformly mixed, 261 mL of an emulsifier solution was added dropwise under stirring at 150 r / min, ultrasonicated at 40 kHz for 15 min, irradiated with a 2000 W ultraviolet lamp at a distance of 10 cm for 10 min under stirring at 150 r / min, washed with pure water three times, filtered, and vacuum dried to obtain hollow microcapsules;

[0064] (2) 32 g of the hollow microcapsules obtained in step (1) were evacuated, 20 g of a metal chelating agent was added, ultrasonic treatment was performed at 20 kHz for 5 h, filtration was performed, and pure water was washed three times to obtain metal extractant microcapsules.

[0065] The cross-linking agent used is obtained from Preparation Example 2; the emulsifier solution used is obtained from Preparation Example 5.

[0066] Example 2

[0067] A method for preparing metal extractant microcapsules comprises the following preparation steps:

[0068] (1) 0.1 mol of ethyl acrylate, 0.25 mol of methacrylamide, 0.2 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 15.41 g of a crosslinking agent, and 3.52 g of an initiator were uniformly mixed, 396 mL of an emulsifier solution was added dropwise under stirring at 150 r / min, ultrasonicated at 40 kHz for 15 min, irradiated with a 2000 W ultraviolet lamp at a distance of 20 cm for 10 min under stirring at 150 r / min, washed with pure water three times, filtered, and vacuum dried to obtain hollow microcapsules;

[0069] (2) 46 g of the hollow microcapsules obtained in step (1) were evacuated, 20 g of a metal chelating agent was added, ultrasonic treatment was performed at 20 kHz for 10 h, filtration was performed, and pure water was washed three times to obtain metal extractant microcapsules.

[0070] The cross-linking agent used is obtained from Preparation Example 2; the emulsifier solution used is obtained from Preparation Example 5.

[0071] Example 3

[0072] A method for preparing metal extractant microcapsules comprises the following preparation steps:

[0073] (1) 0.1 mol of ethyl acrylate, 0.2 mol of methacrylamide, 0.175 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 11.40 g of a crosslinking agent, and 3.04 g of an initiator were uniformly mixed, 326 mL of an emulsifier solution was added dropwise under a stirring condition of 150 r / min, ultrasonicated at 40 kHz for 15 min, irradiated with a 2000 W ultraviolet lamp at a distance of 15 cm for 10 min under a stirring condition of 150 r / min, washed with pure water three times, filtered, and vacuum dried to obtain hollow microcapsules;

[0074] (2) 39 g of the hollow microcapsules obtained in step (1) were evacuated, 20 g of a metal chelating agent was added, ultrasonic treatment was performed at 20 kHz for 8 h, filtration was performed, and the microcapsules were washed with pure water for 3 times to obtain metal extractant microcapsules.

[0075] The cross-linking agent used is obtained from Preparation Example 2; the emulsifier solution used is obtained from Preparation Example 5.

[0076] Example 4

[0077] A method for preparing metal extractant microcapsules, the specific implementation method is the same as Example 3, the difference is that the cross-linking agent used is obtained from Preparation Example 3.

[0078] Example 5

[0079] A method for preparing metal extractant microcapsules, the specific implementation method is the same as Example 3, except that the cross-linking agent used is obtained from Preparation Example 4.

[0080] Example 6

[0081] A method for preparing metal extractant microcapsules, the specific implementation method is the same as Example 3, the difference is that the emulsifier solution used is obtained from Preparation Example 6.

[0082] Example 7

[0083] A method for preparing metal extractant microcapsules comprises the following preparation steps:

[0084] (1) 0.1 mol of ethyl acrylate, 0.1 mol of methacrylamide, 0.175 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 9.96 g of a crosslinking agent, and 2.4 g of an initiator were uniformly mixed, 326 mL of an emulsifier solution was added dropwise under stirring conditions of 150 r / min, ultrasonicated at 40 kHz for 15 min, irradiated with a 2000 W ultraviolet lamp at a distance of 15 cm for 10 min under stirring conditions of 150 r / min, washed with pure water three times, filtered, and vacuum dried to obtain hollow microcapsules;

[0085] (2) 39 g of the hollow microcapsules obtained in step (1) were evacuated, 20 g of a metal chelating agent was added, ultrasonic treatment was performed at 20 kHz for 8 h, filtration was performed, and the microcapsules were washed with pure water for 3 times to obtain metal extractant microcapsules.

[0086] The cross-linking agent used is obtained from Preparation Example 2; the emulsifier solution used is obtained from Preparation Example 5.

[0087] Example 8

[0088] A method for preparing metal extractant microcapsules comprises the following preparation steps:

[0089] (1) 0.1 mol of ethyl acrylate, 0.2 mol of methacrylamide, 0.1 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 8.48 g of a crosslinking agent, and 2.56 g of an initiator were uniformly mixed, 326 mL of an emulsifier solution was added dropwise under stirring at 150 r / min, ultrasonicated at 40 kHz for 15 min, irradiated with a 2000 W ultraviolet lamp at a distance of 15 cm for 10 min under stirring at 150 r / min, washed with pure water three times, filtered, and vacuum dried to obtain hollow microcapsules;

[0090] (2) 39 g of the hollow microcapsules obtained in step (1) were evacuated, 20 g of a metal chelating agent was added, ultrasonic treatment was performed at 20 kHz for 8 h, filtration was performed, and the microcapsules were washed with pure water for 3 times to obtain metal extractant microcapsules.

[0091] The cross-linking agent used is obtained from Preparation Example 2; the emulsifier solution used is obtained from Preparation Example 5.

[0092] Example 9

[0093] A method for preparing metal extractant microcapsules, the specific implementation method is the same as that of Example 3, except that 30g of metal chelating agent is used.

[0094] Comparative Example 1

[0095] A method for preparing metal extractant microcapsules, the specific implementation method is the same as that of Example 3, except that an equal molar amount of styrene is used instead of methacrylamide.

[0096] Performance test of metal extractant microcapsules

[0097] The following performance tests were performed on the embodiments and comparative examples:

[0098] 1. Encapsulation efficiency test of metal extractant microcapsules

[0099] Weigh 5 g of the metal extractant microcapsules obtained in the embodiment and the comparative example, grind them in a mortar for 10 min, add 10 mL of dichloromethane, ultrasonicate at 40 KHz for 15 min, and centrifuge to obtain a supernatant and a solid. Repeat this extraction process 5 times, and dry the solid in a vacuum oven to a constant weight, weigh it and record it as M, and calculate it according to the following formula: Encapsulation efficiency (%) = 100% * (1-M / 5); 5 is the mass of the metal extractant microcapsules. The specific test results are shown in Table 1.

[0100] Table 1

[0101]

[0102] As shown in Table 1, the encapsulation rate of the metal chelating agent in the microcapsules of Examples 1-3 is relatively high, reaching more than 75%. Compared with Example 3, the amount of 1,4-butanediol dimethacrylate and hexanediol dimethacrylate used in the cross-linking agent in Examples 4 and 5 is changed, so that the cross-linking effect of ethyl acrylate, methacrylamide and 2-acrylamide-2-methylpropanesulfonic acid sodium salt is weakened, thereby reducing the encapsulation rate of the wall material for the metal chelating agent; the emulsifier solution used in Example 6 is composed of sodium dodecylbenzene sulfonate dissolved in water, and the emulsification effect of sodium dodecylbenzene sulfonate is worse than the emulsification effect of the emulsifier formed by the compounding of sodium ethylenediamine ethanesulfonate and sodium dodecyl diphenyl oxide disulfonate, which affects the formation of the wall material. Thus, the encapsulation rate is reduced; in Examples 7 and 8, the molar ratios of ethyl acrylate, methacrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt are changed respectively, which affects the occurrence of polymerization reaction and changes the performance of the wall material, thereby reducing the encapsulation rate; in Example 9, the amount of metal chelating agent used is relatively large, which is prone to agglomeration and also causes a decrease in the encapsulation rate; and in Comparative Example 1, styrene is used instead of methacrylamide, which, on the one hand, affects the formation of the wall material, and on the other hand, styrene lacks functional groups that are easy to generate intermolecular forces with the functional groups of the metal chelating agent, so that the encapsulation rate is reduced to a certain extent.

[0103] 2. Adsorption performance test of metal extractant microcapsules

[0104] Based on the data of Test 1, the metal extractant microcapsules obtained in Example 3 and Comparative Example 1 were selected to perform metal ion adsorption performance tests:

[0105] 1 g of the metal extractant microcapsules of Example 3 and Comparative Example 1 and 1 g of the metal chelating agent of Preparation Example 1 were respectively placed in 200 mL of a pH=5 mixed solution (the mixed solution included 0.03 mol of copper sulfate pentahydrate, 0.001 mol of lead sulfate, 0.001 mol of nickel sulfate, 0.001 mol of zinc sulfate, 0.001 mol of iron sulfate, 0.001 mol of cobalt sulfate, 0.001 mol of magnesium sulfate, and 0.001 mol of chromium sulfate), allowed to stand for 20 min, filtered with a 1 micron filter membrane, and then the metal ion concentration in the solution was tested, and the removal rate was calculated according to the following formula: R=100%*(C0-C1) / C0, wherein C0 is the concentration of each metal ion in the solution before the test; C1 is the concentration of each metal ion in the solution after the test (unit: mol / L);

[0106] Among them, the copper ion concentration is determined according to the sodium diethyldithiocarbamate spectrophotometry in the national standard GB / T 7474-87; the lead ion concentration is determined according to the dithizone spectrophotometry in the national standard GB / T 7470-87; the nickel ion concentration is determined according to the dimethylglyoxime spectrophotometry in the national standard GB 11910-89; the zinc ion concentration is determined according to the dithizone spectrophotometry in the national standard GB 7472-87; the iron ion is determined according to the o-phenanthroline spectrophotometry in the national standard HJ / T 345-2007; the cobalt ion is determined according to the flame atomic absorption spectrophotometry in the national standard HJ 957-2018; the magnesium ion concentration is determined according to the ion chromatography in the national standard HJ 812-2016; the chromium ion concentration is determined according to the flame atomic absorption spectrophotometry in the national standard HJ 757-2015. The specific test results are shown in Table 2.

[0107] Table 2

[0108]

[0109] As shown in Table 2, at the same usage amount, the metal extractant microcapsules prepared in Example 3 have better adsorption performance for metal ions than the metal chelating agent obtained in Preparation Example 1, and have better removal effects on copper ions, lead ions, nickel ions, zinc ions, iron ions, cobalt ions, magnesium ions and chromium ions, which can reduce production costs to a certain extent. Compared with Example 3, styrene is used instead of methacrylamide in Comparative Example 1, which affects the formation of microcapsule wall materials and the encapsulation rate of metal chelating agents on the one hand, and on the other hand, the adsorption performance of the prepared metal extractant microcapsules on metals is also reduced.

[0110] The above is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present application. Although the present application is disclosed as above in the preferred embodiment, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution.

Claims

1. A method for preparing metal extractant microcapsules, characterized in that: The method comprises the following preparation steps: (1) Ethyl acrylate, methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid sodium salt, a crosslinking agent, and an initiator are uniformly mixed, an emulsifier solution is added dropwise under stirring, ultrasonication is performed, ultraviolet light is irradiated under stirring for 10-20 minutes, and then the hollow microcapsules are washed with pure water, separated, and dried to obtain hollow microcapsules; (2) evacuating the hollow microcapsules obtained in step (1), adding a metal chelating agent, ultrasonically treating for 5-10 hours, filtering, and washing to obtain metal extractant microcapsules.

2. The method for preparing metal extractant microcapsules according to claim 1, characterized in that: The molar ratio of the ethyl acrylate, methacrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt is 1:(1.5-2.5):(1.5-2).

3. The method for preparing metal extractant microcapsules according to claim 1, characterized in that: The crosslinking agent includes 1,4-butanediol dimethacrylate and hexanediol dimethacrylate in a mass ratio of (25-30):

1.

4. The method for preparing metal extractant microcapsules according to claim 3, characterized in that: The usage amount of the cross-linking agent is 15-20% of the total mass of ethyl acrylate, methacrylamide and 2-acrylamide-2-methylpropanesulfonic acid sodium salt.

5. The method for preparing metal extractant microcapsules according to claim 1, characterized in that: The initiator is one or more of benzoin and its derivatives, acetophenones, aromatic ketones and acylphosphine oxides.

6. The method for preparing metal extractant microcapsules according to claim 1, characterized in that: The emulsifier in the emulsifier solution is one or more of sodium ethylenediamine ethanesulfonate, sodium dodecyl diphenyl ether disulfonate, and dodecylbenzene sulfonate; and the mass concentration of the emulsifier solution is 2-4.5wt%.

7. The method for preparing metal extractant microcapsules according to claim 6, characterized in that: The usage amount of the emulsifier is 16-18% of the total mass of ethyl acrylate, methacrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt.

8. The method for preparing metal extractant microcapsules according to claim 1, characterized in that: The mass ratio of the hollow microcapsules to the metal chelating agent in step (2) is (1.6-2.3):

1.

9. The method for preparing metal extractant microcapsules according to claim 1, characterized in that: The structural formula of the metal chelator is:

10. A metal extractant microcapsule prepared by the preparation method according to any one of claims 1 to 9.

Images