阅读说明：本技术 一种选择性吸附汞树脂材料的制备方法及其在含硒溶液中脱除汞的应用 (Preparation method of resin material for selectively adsorbing mercury and application of resin material in removing mercury in selenium-containing solution ) 是由 郭学益 朱明涛 许志鹏 田庆华 李栋 于 2021-06-16 设计创作，主要内容包括：本发明公开了一种选择性吸附汞树脂材料的制备方法：将由丙烯酸甲酯、二乙烯苯和致孔剂组成的油相与水相混合并搅拌,升温进行反应,得到丙烯酸甲酯-二乙烯苯球；将丙烯酸甲酯-二乙烯苯球在惰性溶剂A中溶胀1～2h,加入胺化剂进行胺化反应,得到胺化树脂；将胺化树脂在惰性溶剂B中溶胀3～6h后,升温至45～50℃,滴入改性剂进行反应,得到选择性吸附汞树脂材料。本发明还公开了该选择性吸附汞树脂材料在含硒溶液中脱除汞的应用。本发明制备方法制备的树脂材料含C＝N和巯基,通过双功能基离子交换树脂吸附含硒溶液中的汞,在两种功能基的协同作用下,使汞的脱除率可以达到99％以上,实现了杂质汞的深度脱除。(The invention discloses a preparation method of a resin material for selectively adsorbing mercury, which comprises the following steps: mixing an oil phase consisting of methyl acrylate, divinylbenzene and a pore-foaming agent with a water phase, stirring, and heating for reaction to obtain methyl acrylate-divinylbenzene spheres; swelling methyl acrylate-divinylbenzene spheres in an inert solvent A for 1-2 h, and adding an amination agent to carry out amination reaction to obtain aminated resin; swelling the aminated resin in an inert solvent B for 3-6 h, heating to 45-50 ℃, and dripping a modifier for reaction to obtain the selectively mercury-adsorbing resin material. The invention also discloses application of the selective mercury adsorption resin material in mercury removal in selenium-containing solution. The resin material prepared by the preparation method contains C-N and sulfydryl, the mercury in the selenium-containing solution is adsorbed by the double-functional group ion exchange resin, the mercury removal rate can reach more than 99 percent under the synergistic action of the two functional groups, and the deep removal of impurity mercury is realized.)

1. The preparation method of the resin material for selectively adsorbing mercury is characterized by comprising the following steps of:

(1) mixing an oil phase consisting of methyl acrylate, divinylbenzene and a pore-foaming agent with a water phase, stirring, heating for reaction, and after the reaction is finished, cooling, filtering, washing, drying and screening to obtain methyl acrylate-divinylbenzene spheres;

(2) swelling the methyl acrylate-divinylbenzene spheres in an inert solvent A for 1-2 h, adding an amination agent for amination reaction, and filtering and washing after the amination reaction is finished to obtain aminated resin;

(3) swelling the aminated resin in an inert solvent B for 3-6 h, heating to 45-50 ℃, dripping a modifier for reaction, and cooling, filtering, washing and drying after the reaction is finished to obtain the selective mercury adsorption resin material.

2. The preparation method according to claim 1, wherein in the step (1), the mass ratio of the methyl acrylate, the pore-forming agent and the divinylbenzene in the oil phase is (7.8-21): (6.9-19): 1, and the pore-forming agent is toluene or acetonitrile; the water phase mainly comprises deionized water, gelatin and sodium chloride, the dosage ratio of the deionized water to the gelatin is 118-185, the unit of the ratio is mL/g, and the mass ratio of the gelatin to the sodium chloride is 1 (30-60).

3. The method according to claim 1, wherein in the step (1), the temperature for the reaction is increased to 70 to 80 ℃ and the reaction time is increased to 5 to 10 hours.

4. The method according to claim 1, wherein in the step (2), the inert solvent A is any one of dimethylformamide, dichloroethane, acetophenone and formamide, the aminating agent is ethylenediamine or N-ethylethylenediamine, and the amount of the aminating agent is 1.5 to 3 times that of methyl acrylate.

5. The preparation method according to claim 1, wherein in the step (2), the amination reaction temperature is 95-125 ℃ and the reaction time is 9-16 h.

6. The preparation method according to claim 1, wherein in the step (3), the inert solvent B is dimethylformamide or formamide, the modifier is one or two of mercaptoacetaldehyde, 2-mercaptopropionaldehyde, 4-mercaptobenzaldehyde, 2-thiosalicylaldehyde and 1, 2-dihydro-2-thio-3-pyridinecarboxaldehyde, and the amount of the modifier is 0.8 to 1 time of that of the aminating agent.

7. The method according to claim 1, wherein in the step (3), the dropping speed of the modifier is 0.5 to 6mL/min, and the reaction time is 6 to 12 hours.

8. The application of the selective mercury adsorption resin material prepared by the preparation method of any one of claims 1 to 7 in mercury removal in selenium-containing solution is characterized by comprising the following steps:

s1: introducing a selenium-containing solution into a resin column, removing mercury by adopting the selective mercury adsorption resin material prepared by the preparation method of any one of claims 1-7, and collecting selenium-containing effluent;

s2: washing the resin column until the effluent liquid is neutral;

s3: and introducing the desorption solution into a resin column, desorbing the resin, and circularly desorbing the desorption solution for 3-6 times to obtain high-concentration mercury-containing desorption solution so as to realize deep removal of mercury in the selenium-containing solution.

9. The preparation method of claim 8, wherein the selenium-containing solution is obtained by oxidizing and volatilizing crude selenium, and has a selenium content of 230-240 g/L, a mercury content of 20-40 mg/L, a tellurium content of 100-150 mg/L and an arsenic content of 10-30 mg/L.

10. The preparation method according to claim 8, wherein in S1, the flow rate of the selenium-containing solution introduced into the resin column is 3-6 BV/h, the exchange temperature is 20-60 ℃, the column passing mode is bottom-in-top-out, and the resin column adopts a single-column or double-column series connection mode;

in S3, the desorption solution is any one of concentrated hydrochloric acid, acidified thiourea solution and KI solution, the flow rate of the desorption solution is 5-7 BV/h, and the desorption solution is fed in and discharged out in a column passing mode.

Technical Field

The invention belongs to the field of purification of selenium-containing solutions, and particularly relates to a preparation method of a selective mercury adsorption resin material and application of the selective mercury adsorption resin material in mercury removal of selenium-containing solutions.

Background

The rare and dispersive metal selenium is not only a strategic element in high-tech electronic products, but also an essential trace element in organisms, and is widely applied to the fields of electronics, chemical pigments, metallurgy, agriculture, biology, cosmetics, medicine and health food industry and the like. In particular, high-purity selenium plays an important role as an important semiconductor material in the production of semiconductor devices, photoelectric and thermoelectric devices, selenium solar cells, optical instruments, electrophotography, laser devices, and the like. With the continuous progress and development of science and technology, the demand of high-purity selenium is increasing day by day, and the research on the purification and preparation methods of high-purity selenium is concerned by more and more researchers.

At present, 90 percent of selenium on the market is extracted from anode mud generated by copper electrorefining, and two main methods for industrially producing the selenium are as follows: one is to oxidize and calcine anode mud and SeO₂Distilling to obtain gaseous SeO₂Captured with solution in a scrubber and then in SO₂Precipitating selenium in an acid medium or an alkali liquor under the action of the selenium; and the other method is to add soda ash to sinter the anode mud in an oxidizing atmosphere to convert the selenium into a sodium selenide or sodium selenate water-soluble solution, and then separate the selenium from the solution through blowing and washing. However, the industrially extracted crude selenium still contains impurities such as tellurium, arsenic, copper, mercury, nickel and the like, and in order to meet the application of high-tech materials, the crude selenium obtained by industrial production must be prepared by high purification.

The methods for preparing high-purity selenium mainly comprise two main types of chemical purification and physical purification. The traditional production method of high-purity selenium mainly uses a chemical method, needs operations such as oxidation, extraction, hydrolysis and the like, and has the defects of long process flow, serious pollution, low recovery rate, high cost, difficult large-scale production and the like. On the other hand, in the preparation process of high-purity selenium, the physical and chemical properties of mercury element are similar to those of selenium, so that the separation difficulty is high. At present, the common methods for separating selenium and mercury are an alkaline leaching method, a CaO selenium fixation and mercury removal method and the like, but the methods have the problems of low recovery rate, high production cost, complex process flow, environmental pollution and the like, and if the content of mercury in high-purity selenium exceeds the standard, the electrical property of the prepared semiconductor material is also seriously influenced. Therefore, the simple and efficient method for removing mercury in the selenium-containing solution is of great significance to the preparation of the high-purity selenium material.

The ion exchange resin fixes the adsorbate on the surface of the resin or in the holes through the adsorption functional group and the holes capable of containing the adsorbate, thereby achieving the purpose of separating, removing and recycling some adsorbates. Compared with separation and enrichment methods such as a chemical precipitation method, an extraction method and the like, the ion exchange method has the advantages of simple process, rapidness, high efficiency and the like, so that the ion exchange method can be used for purifying selenium-containing solution to remove mercury. However, the prior mercury-removing resin has the defects of unsafe preparation process, low selectivity, high preparation cost, difficult regeneration of the resin and the like. The patent application with the publication number of CN107652377A discloses a preparation method of a polyfunctional group modified chelating resin, wherein styrene and stilbene are used as raw materials to prepare polymer microspheres, iminodiacetic acid, thiourea and aminothiol groups are introduced to the surfaces of the copolymer microspheres, and the prepared ion exchange resin contains a plurality of functional groups with different properties, so that various metals such as copper, lead, cadmium, zinc, mercury, silver, palladium and the like can be adsorbed, but the selectivity of the resin to specific metals is poor, and a highly toxic substance chloromethyl ether is required to be used for carrying out a chloromethylation reaction in the preparation process of the resin, so that the preparation method is not beneficial to safety and environmental protection. The prior common styrene ion exchange resin also has the problem of weak hydrophilicity, so that the time for the resin to reach adsorption equilibrium is longer. Application publication No. CN109666179A discloses a preparation method of macroporous weakly-basic acrylic exchange resin, which improves the water content and thermal stability of acrylic resin, but the preparation of the resin uses more raw materials, and has complex process and great difficulty in practical application. Publication No. CN109289807A discloses a preparation method of a mercury ion adsorption resin, the resin is obtained by the reaction of ester group-containing resin and a thiol-containing modifier, and the resin contains thiol, so that the resin has certain selectivity to mercury ions, and the adsorption capacity can reach 412.9mg/g, but the resin has poor applicability and stability, and has the problems of resin poisoning and the like, and the preparation process of the resin requires operations such as nitrogen protection and the like, so that the preparation cost is high, and the process is complex. Patent publication No. CN108975290A discloses a device and a method for removing impurities from mercury-containing crude selenium, wherein in the method, CH-95 type or CH-97 type ion exchange resin is used for removing mercury, but the CH-95 type ion exchange resin cannot be regenerated, so that the cost of selenium and mercury separation is increased.

Aiming at various defects in the prior art, the development of a resin material which is safe, environment-friendly, high in selectivity, easy to regenerate, simple in preparation process and low in cost for the purification and mercury removal process of the selenium-containing solution is of great significance.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects and shortcomings mentioned in the background technology, and provide a preparation method of a selective mercury adsorption resin material and application thereof in mercury removal in selenium-containing solution.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a preparation method of a resin material for selectively adsorbing mercury comprises the following steps:

(1) preparation of resin balls: mixing an oil phase consisting of methyl acrylate, divinylbenzene and a pore-foaming agent with a water phase, stirring, heating for reaction, and after the reaction is finished, cooling, filtering, washing with water, air-drying and screening to obtain a methyl acrylate-divinylbenzene macroporous white sphere;

(2) amination modification: swelling the methyl acrylate-divinylbenzene macroporous white spheres in an inert solvent A for 1-2 h, adding an amination agent for amination reaction, and filtering and washing after the amination reaction is finished to obtain aminated resin;

(3) schiff base reaction: swelling the aminated resin in an inert solvent B for 3-6 h, heating to 45-50 ℃, dripping a modifier for reaction, and after the reaction is finished, cooling, filtering, washing and drying to obtain a resin material for selectively adsorbing mercury, namely the macroporous acrylic acid ion exchange resin containing C ═ N and sulfydryl.

In the preparation method, preferably, in the step (1), the mass ratio of the methyl acrylate, the pore-forming agent and the divinylbenzene in the oil phase is (7.8-21): 6.9-19): 1, and the pore-forming agent is toluene or acetonitrile; the water phase mainly comprises deionized water, gelatin and sodium chloride, the dosage ratio of the deionized water to the gelatin is 118-185, the unit of the ratio is mL/g, and the mass ratio of the gelatin to the sodium chloride is 1 (30-60). In the step (1), the acrylic polymer with good hydrophilicity is used as a resin framework, so that the use of highly toxic substance chloromethyl ether is avoided, the subsequent modification is easy, and the acrylic resin has good hydrophilicity and can improve the adsorption efficiency.

In the preparation method, preferably, in the step (1), the temperature of the temperature-rising reaction is 70-80 ℃, and the time of the temperature-rising reaction is 5-10 hours.

In the preparation method, in the step (2), the inert solvent a is any one of dimethylformamide, dichloroethane, acetophenone and formamide, the amination agent is ethylenediamine or N-ethyl ethylenediamine, and the amount of the amination agent substance is 1.5 to 3 times that of methyl acrylate. The inert solvent A is selected to have a boiling point higher than the temperature of the amination reaction, and the aminating agent is selected to contain a secondary amine to reduce the occurrence of side reactions, by which the amine groups required for the subsequent Schiff base reaction are introduced.

In the preparation method, preferably, in the step (2), the amination reaction temperature is 95-125 ℃, and the reaction time is 9-16 hours.

In the preparation method, preferably, in the step (3), the inert solvent B is dimethylformamide or formamide, the modifier is one or two of mercaptoacetaldehyde, 2-mercaptopropionaldehyde, 4-mercaptobenzaldehyde, 2-thiosalicylaldehyde and 1, 2-dihydro-2-thio-3-pyridinecarboxaldehyde, the amount of the modifier is 0.8-1 time of that of the aminating agent, and the mass fraction of the modifier is 30% -80%.

Further, in the step (3) of the present invention, in the Schiff base reaction, a nucleophilic addition reaction is performed between aldehyde and ketone compounds containing carbonyl groups and primary amine compounds, the nucleophilic reagent is an amine compound, and when the reaction is performed, a nitrogen atom with a lone electron pair attacks a carbon atom with a positive charge on a carbonyl group, and the nucleophilic addition reaction is completed to form an intermediate α -hydroxylamine compound, but the intermediate product is unstable and is rapidly dehydrated to generate a compound containing a C ═ N double bond, and the Schiff base reaction schematic diagram is shown in fig. 1 (taking ethylenediamine and mercaptoacetaldehyde as examples). The sp2 hybridized orbit of the nitrogen atom has a pair of lone pair electrons, so the coordination compound has good coordination performance, can be chelated with mercury, and has good selectivity to the mercury. Furthermore, in the Schiff base reaction, a group with smaller steric hindrance is selected, so that the reaction is more favorably carried out, and the Schiff compound obtained by the reaction has better stability and coordination to specific metal, and can also be used in the fields of catalysis, medicines and the like.

Furthermore, in the step (3) of the present invention, the thiol group in the modifier contains S, and according to the principle of hard soft acid base, the thiol group as soft base has a strong affinity with metallic mercury as soft acid, and the introduction of the thiol group can form a synergistic adsorption with Schiff base (C ═ N), thereby further increasing the adsorption capacity of the resin and the selectivity for mercury.

In the preparation method, preferably, in the step (3), the dropping speed of the modifier is 0.5-6 mL/min, and the reaction time is 6-12 h. The dropping speed of the modifier has great influence on the success of modification, and if the dropping speed is too high, the polymerization reaction of aldehydes per se is possibly aggravated, and the reaction yield is reduced; if the dropping speed is too slow, the production efficiency is lowered. The reaction time is controlled in a proper interval, the reaction time is too short, the reaction is incomplete, and the adsorption capacity of the product is reduced; if the reaction time is too long and side reactions increase, the yield of the target product decreases.

As a general inventive concept, the present invention also provides an application of the selective mercury adsorption resin material prepared by the above preparation method in mercury removal from selenium-containing solution, comprising the following steps:

s1: introducing the selenium-containing solution into a resin column, removing mercury by adopting the selective mercury-adsorbing resin material prepared by the preparation method, and collecting selenium-containing effluent liquid;

s2: washing the resin column until the effluent liquid is neutral;

s3: and introducing the desorption solution into a resin column, desorbing the resin, and circularly desorbing the desorption solution for 3-6 times to obtain high-concentration mercury-containing desorption solution so as to realize deep removal of mercury in the selenium-containing solution.

The adsorption process in the above preparation method, S1, is schematically shown in fig. 2.

In the preparation method, the selenium-containing solution is preferably obtained by oxidizing and volatilizing crude selenium and separating the crude selenium from high-boiling-point substances such as Fe, Ni, Cu, Pb, Ag and the like, wherein the selenium content is 230-240 g/L, the mercury content is 20-40 mg/L, the tellurium content is 100-150 mg/L, and the arsenic content is 10-30 mg/L.

In the preparation method, preferably, in S1, the flow rate of the selenium-containing solution introduced into the resin column is 3-6 BV/h, the exchange temperature is 20-60 ℃, the column passing mode is that the selenium enters from the bottom and goes out from the top, and the resin column adopts a single-column or double-column series connection mode; when the flow rate of the feed liquid is too high, the contact time of the resin and the filtrate is shortened, and the mercury removal rate of the resin is reduced; and when the liquid inlet flow rate is too small, the treatment time is prolonged, the mercury removal efficiency is reduced, and the liquid inlet flow rate is preferably 5-6 BV/h.

In S3, the desorption solution is any one of concentrated hydrochloric acid, acidified thiourea solution and KI solution, the flow rate of the desorption solution is 5-7 BV/h, and the desorption solution is fed in and discharged out in a column passing mode.

Compared with the prior art, the invention has the advantages that:

(1) the resin material prepared by the preparation method contains C ═ N and sulfydryl, mercury in a selenium-containing solution is adsorbed by the double-functional group ion exchange resin, under the synergistic action of the two functional groups, the resin material has larger adsorption capacity and mercury selectivity compared with a single-functional group resin, and the applicability and stability of the mercury-removing resin in a complex environment are also improved by introducing Schiff base reaction; in the practical application of removing mercury from selenium-containing solution, loss of selenium and introduction of impurity elements are avoided through selective adsorption of the resin, so that the removal rate of mercury can reach more than 99%, and the deep removal of impurity mercury is realized.

(2) In the preparation process of the selective mercury adsorption resin material, the acrylic polymer is used as a resin framework, so that the use of chloromethyl ether which is a highly toxic carcinogenic substance in the preparation process of conventional styrene resin is avoided, and the acrylic resin has strong pollution resistance and is not easy to generate a poisoning phenomenon in the use process; meanwhile, the skeleton of the acrylic resin has certain hydrophilicity, and the solution of the acrylic resin can quickly infiltrate the resin, so that the resin is swelled, the time for the metal ions to diffuse into the resin is shortened, and the resin can quickly reach adsorption balance, thereby improving the adsorption efficiency.

(3) According to the invention, the number of functional groups is increased by modifying the methyl acrylate-divinylbenzene macroporous white spheres, so that the adsorption capacity of the resin is improved; in the process of modifying the resin, only one Schiff base reaction is needed, two functional groups with high selectivity to mercury, namely C-N and sulfydryl, can be introduced simultaneously, the preparation process flow of the multifunctional-group ion exchange resin is simplified, and meanwhile, the reaction conditions required by the reaction are mild, so that the preparation cost of the resin is reduced.

(4) The preparation process of the selective mercury adsorption resin material is low in cost and easy to regenerate after adsorption, when the selective mercury adsorption resin material is desorbed in a strong acid solution, mercury is more easily desorbed due to protonation of amine groups, the resin poisoning degree is low, the cyclic use performance of the resin is improved, and the resin can be recycled for more than 15 times on the premise of not reducing the adsorption capacity.

Description of the drawings:

FIG. 1 is a schematic diagram of the Schiff base reaction principle according to the present invention.

FIG. 2 is a schematic view of the adsorption of a resin according to the present invention.

Detailed Description

In order to facilitate an understanding of the invention, the invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

Example 1:

the preparation method of the selective mercury adsorption resin material comprises the following steps:

(1) preparation of resin balls: adding gelatin and sodium chloride in a mass ratio of 1:40 into a reaction kettle with a volume of 10L, then adding deionized water (the mass ratio of the deionized water to the gelatin is 150:1) to form a water phase, stirring and heating to 35 ℃, adding an oil phase (divinylbenzene, toluene and methyl acrylate in a mass ratio of 1:11:13) into the reaction kettle to be mixed with the water phase, wherein the mass ratio of the water phase to the oil phase is 2.2:1, heating to 70 ℃, reacting for 6.5 hours, then finishing the reaction, cooling, vacuum filtering to remove mother liquor, washing with deionized water, air-drying and screening to obtain the methyl acrylate-divinylbenzene macroporous white spheres.

(2) Amination modification: adding the methyl acrylate-divinylbenzene macroporous resin white spheres obtained in the step (1) into a reaction kettle, swelling in dimethylformamide for 2h, raising the temperature to 100 ℃, adding ethylenediamine into the reaction kettle, wherein the mass ratio of the ethylenediamine to the methyl acrylate is 2.2:1, stirring and reacting for 11h, finishing, carrying out vacuum filtration to obtain resin spheres, washing for 3 times by using deionized water until a washing liquid is neutral, and obtaining the aminated modified resin.

(3) Schiff base reaction: swelling the aminated resin obtained in the step (2) in dimethylformamide for 3h, heating to 45 ℃, starting stirring, slowly dripping mercaptoacetaldehyde at a speed of 4mL/min, wherein the mass ratio of mercaptoacetaldehyde to ethylenediamine is 1:1, the reaction time is 8h, after the reaction is finished, carrying out vacuum filtration after the product is cooled, repeatedly washing the obtained resin ball with deionized water until the washing liquid is neutral, and finally drying to obtain the macroporous acrylic acid ion exchange resin containing C ═ N and sulfydryl.

The macroporous acrylic acid ion exchange resin containing C ═ N and mercapto groups prepared in this example was used to remove mercury from selenium-containing solutions, and the specific procedure was as follows:

s1: after the content of the main elements of the selenium-containing solution (see table 1) was measured, the selenium-containing solution was introduced into a resin column at a flow rate of 5BV/h, the exchange temperature was 25 ℃, the column-passing mode was downward-in-upward-out, the resin column was a single column, the macroporous acrylic ion exchange resin containing C ═ N and mercapto groups prepared in this example was used for demercuration, and the effluent containing selenium was collected, and after adsorption by the resin, the mercury content of the solution was reduced from 33.57mg/L to 0.34mg/L, and the result was shown in table 1, and the adsorption rate of the resin to mercury was 99.0%.

S2: washing the resin column by using deionized water until the effluent liquid is neutral;

s3: and introducing 6mol/L concentrated hydrochloric acid serving as desorption liquid into a resin column at the flow rate of 6BV/h, and desorbing the resin, wherein the desorption rate is 98.5%.

TABLE 1 EXAMPLE 1 content of major elements (mg/L) in the solution before and after resin treatment

Element(s)	Selenium	Mercury	Arsenic (As)	Tellurium
					Before treatment	236712	33.57	10.23	101.17
After treatment	236796	0.34	9.92	101.09

Example 2:

the preparation method of the selective mercury adsorption resin material comprises the following steps:

(1) preparation of resin balls: adding gelatin and sodium chloride in a mass ratio of 1:43.5 into a reaction kettle with a volume of 10L, adding deionized water (the mass ratio of the deionized water to the gelatin is 145:1) to form a water phase, stirring and heating to 35 ℃. Adding an oil phase (divinylbenzene, toluene and methyl acrylate in a mass ratio of 1:12.5: 14) into a reaction kettle, mixing with a water phase, wherein the mass ratio of the water phase to the oil phase is 2.3:1, heating to 75 ℃, and reacting for 8 hours. And after the reaction is finished, sequentially cooling, vacuum filtering to remove mother liquor, washing with deionized water, air-drying and screening to obtain the methyl acrylate-divinylbenzene macroporous white spheres.

(2) Amination modification: adding the methyl acrylate-divinylbenzene macroporous white spheres obtained in the step (1) into a reaction kettle, swelling in dimethylformamide for 1.5h, raising the temperature to 110 ℃, adding N-ethyl ethylenediamine into the reaction kettle in a mass ratio of 3:1 to methyl acrylate, stirring and reacting for 13h, finishing, carrying out vacuum filtration to obtain resin spheres, washing for 3 times by using deionized water until a washing solution is neutral, and obtaining the aminated modified resin.

(3) Schiff base reaction: swelling the aminated resin obtained in the step (2) in dimethylformamide for 4h, heating to 50 ℃, starting stirring, slowly dropping 2-thiosalicylaldehyde at the speed of 6mL/min, wherein the mass ratio of the 2-thiosalicylaldehyde to the N-ethyl ethylenediamine is 0.9:1, reacting for 10h, cooling after the reaction is finished, then carrying out vacuum filtration, repeatedly washing the obtained resin ball with deionized water until the washing liquid is neutral, and finally drying to obtain the macroporous acrylic acid ion exchange resin containing C ═ N and sulfydryl.

The macroporous acrylic acid ion exchange resin containing C ═ N and mercapto groups prepared in this example was used to remove mercury from selenium-containing solutions, and the specific procedure was as follows:

s1: after the content of the main elements of the selenium-containing solution (see table 2) was measured, the selenium-containing solution was introduced into a resin column at a flow rate of 6BV/h, the exchange temperature was 25 ℃, the column-passing mode was downward-in-upward-out, the resin column was a single column, the macroporous acrylic ion exchange resin containing C ═ N and mercapto groups prepared in this example was used for mercury removal, and the effluent containing selenium was collected, and after adsorption by the resin, the mercury content of the solution was reduced from 34.73mg/L to 0.25mg/L, and the result is shown in table 2, and the adsorption rate of the resin to mercury was 99.3%.

S2: washing the resin column by using deionized water until the effluent liquid is neutral;

s3: introducing 2.5mol/L acidified thiourea solution serving as desorption solution into a resin column at the flow rate of 7BV/h, and desorbing the resin, wherein the desorption rate is 98.0%.

TABLE 2 EXAMPLE 2 content of major elements (mg/L) in the solution before and after resin treatment

Element(s)	Selenium	Mercury	Arsenic (As)	Tellurium
					Before treatment	236989	34.73	9.96	116.47
After treatment	236982	0.25	9.89	116.38

Example 3:

the preparation method of the selective mercury adsorption resin material comprises the following steps:

(1) preparation of resin balls: adding gelatin and sodium chloride in a mass ratio of 1:52.4 into a reaction kettle with the volume of 10L, then adding deionized water (the mass ratio of the deionized water to the gelatin is 147.6:1) to form a water phase, stirring and heating to 35 ℃. Adding an oil phase (divinylbenzene, toluene and methyl acrylate in a mass ratio of 1:10: 11) into a reaction kettle, mixing with a water phase, wherein the mass ratio of the water phase to the oil phase is 2.35:1, heating to 80 ℃, and reacting for 9.5 hours. And after the reaction is finished, sequentially cooling, removing the mother liquor by vacuum filtration, washing with deionized water, air-drying and screening to obtain the methyl acrylate-divinylbenzene macroporous white spheres.

(2) Amination modification: adding the methyl acrylate-divinylbenzene macroporous white spheres obtained in the step (1) into a reaction kettle, swelling in acetophenone for 2h, heating to 125 ℃, adding ethylenediamine into the reaction kettle according to the mass ratio of 2:1 to methyl acrylate, stirring and reacting for 14h, finishing, carrying out vacuum filtration to obtain resin spheres, washing for 3 times by using deionized water until a washing liquid is neutral, and obtaining the aminated modified resin.

(3) Schiff base reaction: swelling the aminated resin obtained in the step (2) in formamide for 5h, heating to 50 ℃, starting stirring, slowly dropping 2-mercaptopropionaldehyde at a speed of 5mL/min, wherein the mass ratio of the 2-mercaptopropionaldehyde to the ethylenediamine is 0.95:1, reacting for 12h, cooling after the reaction is finished, carrying out vacuum filtration, repeatedly washing the obtained resin ball with deionized water until the washing liquid is neutral, and finally drying to obtain the macroporous acrylic acid ion exchange resin containing C ═ N and mercapto.

The macroporous acrylic acid ion exchange resin containing C ═ N and mercapto groups prepared in this example was used to remove mercury from selenium-containing solutions, and the specific procedure was as follows:

s1: after the content of main elements in the selenium-containing solution (see table 3) is measured, the selenium-containing solution is introduced into a resin column at the flow rate of 6BV/h, the exchange temperature is 25 ℃, the column passing mode is downward-in-upward-out, the resin column adopts a single column, the macroporous acrylic acid series ion exchange resin containing C ═ N and sulfydryl prepared in the embodiment is used for removing mercury, the effluent liquid containing selenium is collected, after the absorption of the resin, the mercury content of the solution is reduced from 32.14mg/L to 0.20mg/L, and the result is shown in table 3, and the mercury absorption rate of the resin reaches 99.4%;

s2: washing the resin column by using deionized water until the effluent liquid is neutral;

s3: introducing 6mol/L concentrated hydrochloric acid desorption solution into a resin column at the flow rate of 6BV/h, and desorbing the resin, wherein the desorption rate is 98.3%.

TABLE 3 EXAMPLE 3 content of major elements (mg/L) in the solution before and after resin treatment

Element(s)	Selenium	Mercury	Arsenic (As)	Tellurium
					Before treatment	237036	32.14	9.37	125.66
After treatment	237031	0.20	9.22	125.50