阅读说明：本技术 一种阴离子交换树脂及其制备方法和应用 (Anion exchange resin and preparation method and application thereof ) 是由 花榕 张雨 刘付平 孔杰 李阳 张峰 何非凡 冯宇 吴金虎 寇晓康 于 2020-03-03 设计创作，主要内容包括：本发明提供了一种阴离子交换树脂及其制备方法和应用,属于稀有金属分离富集技术领域。本发明提供的阴离子交换树脂的制备方法,包括以下步骤：将聚苯乙烯-二乙烯苯聚合物和氯甲醚混合,在氯化锌催化作用下进行氯甲基化反应,得到氯甲基化聚苯乙烯-二乙烯苯聚合物；将所述氯甲基化聚苯乙烯-二乙烯苯聚合物、正丁醇和三乙胺混合,在碱性条件下进行氨基化反应,得到阴离子交换树脂。采用本发明提供的方法制备得到的阴离子交换树脂,能够选择性吸附铼,实现其分离富集,且所述阴离子交换树脂吸附平衡时间短、pH值适用范围较大。(The invention provides an anion exchange resin and a preparation method and application thereof, belonging to the technical field of rare metal separation and enrichment. The preparation method of the anion exchange resin provided by the invention comprises the following steps: mixing a polystyrene-divinylbenzene polymer and chloromethyl ether, and carrying out chloromethylation reaction under the catalytic action of zinc chloride to obtain a chloromethylated polystyrene-divinylbenzene polymer; mixing the chloromethylated polystyrene-divinylbenzene polymer, n-butyl alcohol and triethylamine, and carrying out amination reaction under an alkaline condition to obtain the anion exchange resin. The anion exchange resin prepared by the method provided by the invention can selectively adsorb rhenium to realize separation and enrichment of the rhenium, and has short adsorption equilibrium time and wide pH value application range.)

1. A method for preparing anion exchange resin is characterized by comprising the following steps:

mixing a polystyrene-divinylbenzene polymer and chloromethyl ether, and carrying out chloromethylation reaction under the catalytic action of zinc chloride to obtain a chloromethylated polystyrene-divinylbenzene polymer;

mixing the chloromethylated polystyrene-divinylbenzene polymer, n-butyl alcohol and triethylamine, and carrying out amination reaction under an alkaline condition to obtain the anion exchange resin.

2. The preparation method according to claim 1, wherein the mass ratio of the polystyrene-divinylbenzene polymer to the chloromethyl ether to the zinc chloride is 5:20 to 30:8 to 12.

3. The method according to claim 1 or 2, wherein the chloromethylation reaction is carried out at a temperature of 40-50 ℃ for 20-28 h.

4. The preparation method according to claim 1, wherein the alkaline condition is such that the pH value of the system is 9-11, and the use amount ratio of the chloromethylated polystyrene-divinylbenzene polymer to n-butyl alcohol to triethylamine is 5g: 90-110 m L: 8-12 g.

5. The preparation method according to claim 1 or 4, wherein the temperature of the amination reaction is 60 to 70 ℃ and the time is 10 to 15 hours.

6. An anion exchange resin prepared by the preparation method of any one of claims 1 to 5.

7. Use of the anion exchange resin of claim 6 for separating enriched rhenium.

8. The application according to claim 7, wherein the application comprises: the rhenium-containing solution is adsorbed with the anion exchange resin and then desorbed.

9. Use according to claim 8, wherein the pH value of the rhenium-containing solution is 1 to 6.

10. Use according to claim 8 or 9, characterized in that the rhenium-containing solution also comprises uranium, which is present in the form of hexavalent uranium.

Technical Field

The invention relates to the technical field of rare metal separation and enrichment, in particular to anion exchange resin and a preparation method and application thereof.

Background

Rhenium is one of the most rare metals on earth, has no independent minerals and is often associated with molybdenite, banzite and sandstone-type uranium ores. Therefore, the development of efficient separation and enrichment technology is the first problem in rhenium production. The separation and enrichment methods of rhenium include a precipitation method, a solvent extraction method, an ion exchange method, a chromatographic separation method, a membrane separation method and the like, wherein the solvent extraction method and the ion exchange method are widely applied.

The ion exchange method is to use the active groups of the ion exchange resin to carry out ion exchange with the rhenium-containing ions in the solution, thereby realizing the separation of rhenium from other substances, and has the advantages of simple process, convenient operation and less environmental hazard. In addition, rhenium is predominantly perrhenate ion (ReO) in slightly acidic and neutral solutions₄ ^-) The form exists, so that the anion exchange resin can be used for effectively separating and enriching rhenium. Liuhong Cao and the like (static adsorption performance of alkalescent resin to rhenium in leacheate [ J)]Rare metal, 2017, 41 (09): 1028-1034) by using a weak alkaline resin to perform static adsorption on rhenium in leacheate, wherein the saturated adsorption capacity of the weak alkaline resin is 60.4 mg-g^-1But the adsorption equilibrium time is longer; pinus Yelloensis et al (Synthesis of weakly basic anion exchange resin and research on adsorption and desorption behaviors of Pinus Yelloensis to rhenium ion [ J)]Ion exchange and adsorption, 2015, 31 (2): 107-114) The saturated adsorption capacity of the weak-base anion exchange resin synthesized by the irradiation grafting technology to rhenium ions is 84.1mg g^-1But it is greatly affected by pH.

Disclosure of Invention

The invention aims to provide anion exchange resin and a preparation method and application thereof, the anion exchange resin prepared by the method can selectively adsorb rhenium to realize separation and enrichment; and the anion exchange resin has short adsorption equilibrium time and larger pH value application range.

In order to achieve the above object, the present invention provides the following technical solutions:

a method for preparing an anion exchange resin, comprising the steps of:

mixing a polystyrene-divinylbenzene polymer and chloromethyl ether, and carrying out chloromethylation reaction under the catalytic action of zinc chloride to obtain a chloromethylated polystyrene-divinylbenzene polymer;

mixing the chloromethylated polystyrene-divinylbenzene polymer, n-butyl alcohol and triethylamine, and carrying out amination reaction under an alkaline condition to obtain the anion exchange resin.

Preferably, the mass ratio of the polystyrene-divinylbenzene polymer to the chloromethyl ether to the zinc chloride is 5: 20-30: 8-12.

Preferably, the temperature of the chloromethylation reaction is 40-50 ℃ and the time is 20-28 h.

Preferably, the alkaline condition is that the pH value of the system is 9-11, and the dosage ratio of the chloromethylated polystyrene-divinylbenzene polymer to the n-butyl alcohol to the triethylamine is 5g: 90-110 m L: 8-12 g.

Preferably, the temperature of the amination reaction is 60-70 ℃, and the time is 10-15 h.

The invention provides the anion exchange resin prepared by the preparation method in the technical scheme.

The invention provides application of the anion exchange resin in the technical scheme in separating and enriching rhenium.

Preferably, the application comprises: the rhenium-containing solution is adsorbed with the anion exchange resin and then desorbed.

Preferably, the pH value of the rhenium-containing solution is 1-6.

Preferably, the rhenium-containing solution also includes uranium, which is present in the form of hexavalent uranium.

The invention provides a preparation method of anion exchange resin, which comprises the following steps: mixing a polystyrene-divinylbenzene polymer and chloromethyl ether, and carrying out chloromethylation reaction under the catalytic action of zinc chloride to obtain a chloromethylated polystyrene-divinylbenzene polymer; mixing the chloromethylated polystyrene-divinylbenzene polymer, n-butyl alcohol and triethylamine, and carrying out amination reaction under an alkaline condition to obtain the anion exchange resin. The anion exchange resin prepared by the method contains-N (CH)₂CH₃)₃The Cl functional group can selectively adsorb rhenium to realize separation and enrichment of the rhenium; and the anion exchange resin has short adsorption equilibrium time and larger pH value application range (namely good acid-base stability).

In the embodiment of the invention, through static adsorption and dynamic adsorption-desorption tests, the influence of factors such as solution acidity, initial concentration, adsorption time, adsorption temperature and the like on the adsorption performance of the anion exchange resin is systematically examined, and the result shows that the initial concentration of the rhenium-containing solution is 100 mg-L under the condition of room temperature (25 ℃)^-1The anion exchange resin is balanced after adsorption for 400min, the acidity has little influence on the adsorption of rhenium, the uranium-rhenium separation effect is optimal when the pH value is 1.5, and the separation coefficient can reach 41.68; the saturated adsorption capacity of the anion exchange resin reaches 129.3mg g^-1The adsorption process accords with an L angmuir adsorption isothermal model and a quasi-second-order kinetic model from the thermodynamic and kinetic analysis, and the adsorption is a spontaneous endothermic process, and in a dynamic adsorption-desorption test, the flow rate of the rhenium-containing solution is controlled to be 0.5m L min^-1The adsorption saturation was reached at 540 resin bed volumes, and the dynamic saturation adsorption capacity reached 76.17 g. L^-1Saturated ratio of 2.35, 1mol · L^-1The ammonia water has better effect of desorbing rhenium, and the rhenium can be desorbed by 8 resin bedsThe desorption is complete, so that the enrichment multiple is close to 70 times, and the method has good industrial application prospect.

Drawings

FIG. 1 is an infrared spectrum of L SC-Re resin before and after adsorbing rhenium;

FIG. 2 is an SEM image of L SC-Re resin before and after adsorbing rhenium;

FIG. 3 is an EDS elemental spectrum before and after rhenium adsorption by L SC-Re resin;

FIG. 4 is a graph of pH versus adsorbed amount of ammonium perrhenate solution;

FIG. 5 is D_U、D_Re、β_Re/UA curve relating to pH;

FIG. 6 is a graph showing the relationship between adsorption time and adsorption amount;

FIG. 7 is a quasi-first order, quasi-second order kinetic curve;

fig. 8 is a graph showing the relationship between the concentration of ammonium perrhenate solution and the amount of adsorption;

FIG. 9 is an adsorption isotherm of L angmuir and Freundlich;

FIG. 10 is a graph of adsorption temperature versus adsorption amount and a thermodynamically fitted curve;

fig. 11 is a dynamic adsorption-desorption curve.

Detailed Description

The invention provides a preparation method of anion exchange resin, which comprises the following steps:

mixing a polystyrene-divinylbenzene polymer and chloromethyl ether, and carrying out chloromethylation reaction under the catalytic action of zinc chloride to obtain a chloromethylated polystyrene-divinylbenzene polymer;

mixing the chloromethylated polystyrene-divinylbenzene polymer, n-butyl alcohol and triethylamine, and carrying out amination reaction under an alkaline condition to obtain the anion exchange resin.

The invention takes the polystyrene-divinylbenzene polymer as the raw material to prepare the anion exchange resin, the source of the polystyrene-divinylbenzene polymer is not specially limited, and the anion exchange resin can be prepared by adopting the method well known by the technicians in the field; in the present invention, the preparation method of the polystyrene-divinylbenzene polymer preferably comprises the following steps:

mixing styrene, divinylbenzene, an initiator and a pore-foaming agent to obtain a first mixed material;

mixing the sodium chloride solution and the carboxymethyl cellulose to obtain a second mixed material;

and mixing the first mixed material and the second mixed material, and then carrying out cross-linking polymerization reaction to obtain the polystyrene-divinylbenzene polymer.

The invention mixes styrene, divinylbenzene, an initiator and a pore-foaming agent to obtain a first mixed material. In the present invention, the initiator is preferably benzoyl peroxide or diethyl hexanoic acid; the pore-foaming agent is preferably polyethylene glycol, toluene, liquid paraffin or 200# gasoline; the mass ratio of the styrene to the divinylbenzene to the initiator to the pore-foaming agent is preferably 40: 5.5-6.5: 0.4-0.6: 18-22, and more preferably 40:6:0.5: 20.

According to the invention, a sodium chloride solution and carboxymethyl cellulose are mixed to obtain a second mixed material, the concentration of the sodium chloride solution is preferably 1 mol/L, and the using amount ratio of the sodium chloride solution to the carboxymethyl cellulose to styrene is preferably 90-110 m L: 0.7-1.3 g:40g, and more preferably 100m L: 1g:40 g.

After the first mixed material and the second mixed material are obtained, the first mixed material and the second mixed material are mixed and then are subjected to cross-linking polymerization reaction to obtain the polystyrene-divinylbenzene polymer. In the present invention, the first mixture and the second mixture are preferably mixed by adding the first mixture to a three-neck flask containing the second mixture by a tubular injection method, and then performing a cross-linking polymerization reaction. In the invention, the temperature of the cross-linking polymerization reaction is preferably 75-85 ℃, and more preferably 80 ℃; the time is preferably 10-15 h, and more preferably 12 h. In the invention, the styrene and divinylbenzene are subjected to a cross-linking polymerization reaction to generate a polystyrene-divinylbenzene polymer, wherein the reaction formula is shown as formula 1:

after the crosslinking polymerization reaction is finished, the method preferably selects filtration, the obtained solid material is washed by water and dried in the air, and then the solid material is screened to obtain the polystyrene-divinylbenzene polymer with the particle size of 0.3-0.5 mm.

After the polystyrene-divinylbenzene polymer is obtained, the polystyrene-divinylbenzene polymer and chloromethyl ether are mixed, and chloromethylation reaction is carried out under the catalysis of zinc chloride to obtain the chloromethylated polystyrene-divinylbenzene polymer. In the invention, the mass ratio of the polystyrene-divinylbenzene polymer to the chloromethyl ether to the zinc chloride is preferably 5: 20-30: 8-12, and more preferably 1:5: 2. The preparation method preferably comprises the steps of mixing the polystyrene-divinylbenzene polymer with chloromethyl ether, swelling for 50-70 min at room temperature, and then adding zinc chloride to carry out chloromethylation reaction. In the invention, the temperature of the chloromethylation reaction is preferably 40-50 ℃, and more preferably 45 ℃; the time is preferably 20-28 h, and more preferably 24 h. In the invention, the polystyrene-divinylbenzene polymer and chloromethyl ether are subjected to chloromethylation reaction to obtain chloromethylated polystyrene-divinylbenzene polymer, wherein the reaction formula is shown as formula 2:

after the chloromethylation reaction is finished, the filtering is preferably carried out, the obtained solid material is washed by absolute ethyl alcohol and deionized water in sequence and then is dried in the air, and the chloromethylated polystyrene-divinylbenzene polymer is obtained.

After obtaining the chloromethylated polystyrene-divinylbenzene polymer, mixing the chloromethylated polystyrene-divinylbenzene polymer, n-butyl alcohol and triethylamine, and carrying out an amination reaction under an alkaline condition to obtain an anion exchange resin, wherein the alkaline condition is preferably that the pH value of a system is 9-11, the alkaline condition is preferably provided by sodium hydroxide, the dosage ratio of the chloromethylated polystyrene-divinylbenzene polymer, the n-butyl alcohol and the triethylamine is preferably 5g: 90-110 m L: 8-12 g, and more preferably 5g:100m L: 10g, the chloromethylated polystyrene-divinylbenzene polymer and the n-butyl alcohol are preferably added into a three-mouth flask provided with a thermometer, a reflux condenser and an electric stirrer, the three-mouth flask is swelled for 50-70 min at room temperature, then sodium hydroxide is added into the three-mouth flask, the temperature of the system is controlled to be 60-70 ℃, the triethylamine is added into the three-mouth flask for the amination reaction, the triethylamine is preferably added into the three-mouth flask at a rate of 2-3 g/min, the temperature of the amination reaction is preferably 60-70 ℃, the triethylamine is more preferably added into the three-mouth flask, the triethylamine is preferably, the triethylamine is added into the three-mouth flask, the amination reaction is preferably carried out at a time of 60-mouth reaction, the anion exchange reaction is preferably 10 h, the anion exchange reaction is preferably represented by a simple formula shown in the formula:

after the amination reaction is finished, the invention preferably selects filtration, and the obtained solid material is washed by deionized water and toluene in sequence and then is filtered to be dry, so as to obtain the anion exchange resin.

The invention provides the anion exchange resin prepared by the preparation method in the technical scheme. In the invention, the anion exchange resin comprises a resin framework and a functional group connected to the resin framework, as shown in formula 3, the resin framework is a methylated polystyrene-divinylbenzene polymer, and the functional group is-N (CH)₂CH₃)₃Cl. in the invention, the degree of crosslinking of the anion exchange resin is preferably 7 to 9, and the content of the functional group is preferably 2 to 3mmol/m L (specifically, calculated by the stacking volume of the anion exchange resin). in the invention, the anion exchange resin is spherical particles, and the diameter is preferably 0.3 to 0.5 mm.

The invention provides application of the anion exchange resin in the technical scheme in separating and enriching rhenium. In the present invention, the application includes: the rhenium-containing solution is adsorbed with the anion exchange resin and then desorbed.

The anion exchange resin is adopted to adsorb rhenium-containing solution. In the invention, the pH value of the rhenium-containing solution is preferably 1-6, under the condition, rhenium exists in the form of positive heptavalent rhenium (Re (VII)), specifically, perrhenate ion (ReO)₄ ^-) The form exists; the rhenium-containing solution preferably also comprises uranium, preferably in the form of hexavalent uranium (u (vi)), in the embodiment of the invention, u (vi) is provided in particular by uranyl sulfate, i.e. u (vi) is UO₂(SO₄)₂ ^2-In the invention, the concentration of Re (VII) in the rhenium-containing solution is preferably 50-180 mg/L, more preferably 100 mg/L, and the concentration of U (VI) is preferably 80-120 mg/L, more preferably 100 mg/L.

In the present invention, the adsorption may be static adsorption or dynamic adsorption, and the present invention is not particularly limited thereto, and may realize efficient adsorption of rhenium.

In the invention, the static adsorption method preferably comprises the following steps of fully swelling the anion exchange resin in distilled water for 10-15 h, mixing the swollen anion exchange resin with a rhenium-containing solution, and adopting the concentration of 2 mol-L^-1H of (A) to (B)₂SO₄Or the concentration is 3 mol. L^-1The ammonia water is used for adjusting the pH value of the system to be 1-6, and then the system is adsorbed in a constant temperature oscillator, in the static adsorption, the dosage ratio of the anion exchange resin to the rhenium-containing solution is preferably 0.02-0.04 g to 20m L, more preferably 0.02g to 20m L, the adsorption temperature is preferably room temperature, i.e. no additional heating or cooling is needed, in the embodiment of the invention, the adsorption is carried out under the condition of 25 ℃, and the adsorption equilibrium time is preferably 4-7 h.

After the static adsorption is finished, the invention preferably carries out desorption; the specific operation steps and the used reagent of desorption are not specially limited, and the desorption method can be selected according to actual needs.

In the present invention, the dynamic adsorption method preferably comprises the steps of wet packing an anion exchange resin in a U-type column of 6.8 phi 6.8 × 75mm in diameter with a bed height of 60mm (about 2m L) and a concentration of 2mol L^-1H of (A) to (B)₂SO₄Or the concentration is 3 mol. L^-1Adjusting the pH value of the rhenium-containing solution to 1-6 by using the ammonia water, then enabling the rhenium-containing solution to flow through the exchange column, and controlling the flow rate of the rhenium-containing solution to be 0.5m L & min^-1And the rhenium is adsorbed.

After the dynamic adsorption is completed, the desorption is preferably carried out in the present invention, and the desorption method preferably comprises the step of using the concentration of 1mol L^-1The ammonia water is used for eluting the exchange column adsorbed with rhenium for a plurality of times until the effluent liquid does not contain rhenium, and the desorption is finished.

The separation and enrichment of rhenium in the rhenium-containing solution can be realized by adopting the method, and the rhenium-containing desorption solution is preferably further processed according to actual needs, such as further concentration, and the method is not particularly limited in this respect.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.