Anhydride modified chelate resin and preparation method and application thereof
阅读说明：本技术 一种酸酐改性螯合树脂及其制备方法和应用 (Anhydride modified chelate resin and preparation method and application thereof ) 是由 蔡建国 石洪燕 刘锐 张锋 于 2021-02-07 设计创作，主要内容包括：本发明涉及一种酸酐改性螯合树脂及其制备方法和应用,制备方法包括以下步骤：将氯甲基聚苯乙烯树脂与AlCl-3溶液、PCl-3溶液混合搅拌,过滤,洗涤,得到改性后的树脂；将金属化合物与水解抑制剂混合搅拌,与改性后的树脂混合；将得到的混合物减压蒸馏,去除多余溶液,加入酸酐搅拌,过滤,洗涤至中性,干燥,得到回收氢氟酸的改性树脂。本发明的改性螯合树脂用于强酸中的氢氟酸与其它无机酸分离,在任意无机酸的存在下显示出更高的除氟能力和亲和力,回收率可达95％以上,通过键合的方式形成稳定的络合物,可防止金属离子流失,不同除氟机理协同作用,提高了除氟吸附能力,用酸洗后可再生,环保经济。(The invention relates to an anhydride modified chelate resin and a preparation method and application thereof, wherein the preparation method comprises the following steps: mixing chloromethyl polystyrene resin with AlCl 3 Solution, PCl 3 Mixing and stirring the solution, filtering and washing to obtain modified resin; mixing and stirring a metal compound and a hydrolysis inhibitor, and mixing the metal compound and the modified resin; distilling the obtained mixture under reduced pressure, removing excessive solution, adding anhydride, stirring, filtering, washing to neutrality, and dryingTo obtain the modified resin for recovering hydrofluoric acid. The modified chelating resin is used for separating hydrofluoric acid from other inorganic acids in strong acid, shows higher defluorination capacity and affinity in the presence of any inorganic acid, has a recovery rate of over 95 percent, forms a stable complex in a bonding mode, can prevent metal ions from losing, has synergistic effect of different defluorination mechanisms, improves defluorination adsorption capacity, is renewable after acid cleaning, and is environment-friendly and economical.)
1. An anhydride modified chelate resin, characterized in that the structure of the modified resin is shown as the following formula:
wherein the content of the first and second substances,the polystyrene resin is chloromethyl polystyrene resin with polymerization degree of 1-10, M is cerium, aluminum or zirconium, and n is 1 or 4.
2. A method for preparing the modified chelating resin of claim 1, comprising the steps of:
(1) mixing chloromethyl polystyrene resin with AlCl3Solution, PCl3Mixing and stirring the solution, filtering and washing to obtain modified resin;
(2) mixing and stirring a metal compound and a hydrolysis inhibitor, and mixing the metal compound and the modified resin obtained in the step (1);
(3) and (3) distilling the mixture obtained in the step (2) under reduced pressure, removing redundant solution, adding acid anhydride, stirring, filtering, washing to be neutral, and drying to obtain the modified resin for recovering hydrofluoric acid.
3. The method of claim 2, wherein: in the step (1), chloromethyl polystyrene resin, AlCl3、PCl3The mass ratio of (A) to (B) is 4-20:1-4: 4-16.
4. The method of claim 2, wherein: in the step (1), the AlCl3Solutions and PCl3The concentration of the solution is 0.25% -4% w/v and 1% -16% w/v, respectively.
5. The method of claim 2, wherein: in step (2), the metal compound is selected from one or more of nitrates, sulfates, hydrochlorides and oxides of cerium, aluminum and zirconium.
6. The method of claim 2, wherein: in the step (2), the hydrolysis inhibitor is selected from a mixed solution of ethanol and water in a volume ratio of 1:1-5 or an acid solution with a mass fraction of 1% -20%.
7. The method of claim 2, wherein: in the step (3), reduced pressure distillation is carried out for 3-8h at the temperature of 60-100 ℃.
8. The method of claim 2, wherein: in the step (3), the acid anhydride is carboxylic anhydride, and the molar ratio of the carboxylic anhydride to the metal compound is 0.01-0.5: 1-5.
9. The method of claim 2, wherein: in the step (3), stirring is carried out for 2-3h at 25-80 ℃.
10. Use of the anhydride-modified chelate resin according to claim 1 for recovering hydrofluoric acid from a waste water containing an inorganic acid.
Technical Field
The invention relates to the field of strong-acid fluorine-containing wastewater defluorination, in particular to an anhydride modified chelating resin and a preparation method and application thereof.
Background
Hydrofluoric acid is used for carving glass, cleaning residual sand on castings, controlling fermentation, electropolishing and cleaning corroded semiconductor silicon wafers and oxygen-containing impurities on the surfaces of stainless steel, and is widely applied to the fields of integrated circuits, photovoltaics, liquid crystal panels and the like. The generated inorganic mixed acid containing hydrofluoric acid is very corrosive acid, and is easy to corrode positions of pipe welding openings, valves, pumps, interfaces and the like, so that industrial leakage is caused. At present, the treatment method of strong acid wastewater comprises the following steps: a neutralization precipitation method, a fluidized bed method or a spray roasting method, a reduced pressure distillation method, a membrane diffusion dialysis method and the like.
The neutralization precipitation method generally utilizes calcium ions and fluoride ions in lime to generate CaF2The fluoride ions are removed by precipitation, and partial industrial enterprises adopt a neutralization method to treat the acid-containing waste liquid so far, but the treated waste residue is large in quantity, and a large amount of generated solid waste is difficult to treat, so that a large amount of acid and metal resources are wasted while secondary pollution is caused. With the strict management of acid washing sludge and the incorporation of dangerous solid wastes in China, the treatment method is necessarily eliminated.
The spray roasting method is widely applied due to relatively low operation energy consumption, but the greatest defect of the spray roasting method is that the by-product is easy to drift and has serious secondary pollution; the by-products of the fluidized bed method and the reduced pressure distillation method do not have secondary dust pollution, but the equipment requirement of the whole set of treatment process is high, and the investment is large.
The membrane diffusion dialysis method is only about 1/5 of roasting method, and has many advantages of ion exchange resin, excellent inorganic ion removing ability, regeneration ability and simple device. According to the Pearson's soft and hard acid-base theory, fluoride is a hard and alkaline substance that exhibits strong affinity for hard and acidic polyvalent metal ions, i.e., Al (III), La (III), Ce (III), Zr (IV), Ti (IV), Mn (II, IV). Based on the above-mentioned properties of fluorides, metal chelate adsorbents have attracted much attention in recent years as an effective defluorination technique. CN108996598A adopts bifunctional metal chelating resin adsorbent to remove fluorine, chelating metal is hydrolyzed under alkaline condition to obtain hydroxyl, and then exchange with anion, and fluorine can not be removed under strong acid environment; CN103274539B removes fluorine in drinking water by controlling pH for many times, and the operation process is complicated.
Disclosure of Invention
In order to solve the technical problems, the invention provides the anhydride modified chelating resin and the preparation method and application thereof, the modified resin chelates metal ions, and then the anhydride modified chelating resin obtains metal oxyhydroxide, different defluorination mechanisms have synergistic effects, the adsorption performance is improved, the modified chelating resin is easy to clean, acid-resistant, alkali-resistant and corrosion-resistant, can be regenerated after acid washing, and has the advantages of low cost, simple preparation process, convenient operation, repeated use, environmental protection and economy.
The structure of the anhydride modified chelating resin is shown as the following formula:
wherein the content of the first and second substances,the polystyrene resin is chloromethyl polystyrene resin with polymerization degree of 1-10, M is cerium, aluminum or zirconium, and n is 1 or 4.
The preparation method of the anhydride modified chelating resin comprises the following steps:
(1) mixing chloromethyl polystyrene resin with AlCl3Solution, PCl3Mixing and stirring the solution, filtering and washing to obtain modified resin;
(2) mixing and stirring a metal compound and a hydrolysis inhibitor, and mixing the metal compound and the modified resin obtained in the step (1);
(3) and (3) distilling the mixture obtained in the step (2) under reduced pressure, removing redundant solution, adding acid anhydride, stirring, filtering, washing to be neutral, and drying to obtain the modified resin for recovering hydrofluoric acid. The synthetic process of the modified resin comprises the following steps:
further, in the step (1), chloromethyl polystyrene resin, AlCl3、PCl3The mass ratio of (A) to (B) is 4-20:1-4: 4-16. Chloromethyl polystyrene resin replaces the traditional resin loaded with metal ions, and AlCl3Solution, PCl3After the solution is mixed, the chlorine-containing group is modified into a phosphate group, and the phosphate group has good complexing ability on metal.
Further, in the step (1), AlCl3Solutions and PCl3The concentrations of the solutions were 0.25% -4% w/v and 1% -16% w/v, respectively, in g/100 mL. Adding AlCl3The purpose of (A) is to catalyze the modification of chlorine-containing groups of chloromethyl polystyrene resin into phosphoric acid groups.
Further, in the step (2), the metal compound is selected from one or more of nitrates, sulfates, hydrochlorides and oxides of cerium, aluminum and zirconium. The metal salt solution is used as a precursor to dip the chloromethyl polystyrene resin, free metal ions in the solution and phosphate groups on the chloromethyl polystyrene resin are chelated in a bonding mode to form a complex, the chemical bond is stable, and the metal ions can be prevented from losing; cerium, aluminum and zirconium are cheap metal elements, form stable phosphate compounds, and show higher defluorination capacity and affinity in the presence of any inorganic acid.
Further, in the step (2), the hydrolysis inhibitor is selected from a mixed solution of ethanol and water in a volume ratio of 1:1-5 or an acid solution with a mass fraction of 1% -20%.
Further, in the step (3), the distillation is carried out for 3 to 8 hours at 60 to 100 ℃ under reduced pressure.
Further, in the step (3), the acid anhydride is a carboxylic anhydride, and the molar ratio of the carboxylic anhydride to the metal compound is 0.01-0.5: 1-5. Acid anhydride is used as a modifier, metal ions chelated on the phosphate group of the resin are further modified by a hydrothermal method to obtain metal oxyhydroxide, and the oxyhydroxide carried by the metal is utilized to remove fluorine in a strong acid environment. The defluorination mechanism is as follows:
ion exchange:
surface synergy:
③ electrostatic adsorption:
further, in step (3), stirring is carried out at 25-80 ℃ for 2-3 h.
The invention also claims the application of the acid anhydride modified chelating resin in recovering hydrofluoric acid from waste water containing inorganic acid.
By the scheme, the invention at least has the following advantages:
(1) after chelating metal ions, the resin material is further modified by anhydride to obtain oxyhydroxide, the adsorption performance is improved through the synergistic action of different mechanisms such as electrostatic adsorption, surface synergy and ion exchange, the defluorination can be realized in a strong acid environment, and the separation recovery rate of hydrofluoric acid and other inorganic acids can reach more than 95%.
(2) According to the invention, chloromethyl polystyrene resin is used as a carrier, chlorine-containing groups are modified into phosphoric acid groups, and metal is loaded on the modified chloromethyl polystyrene resin in a bonding manner, so that the metal is not easy to dissolve and damage, easy to clean, acid-resistant, alkali-resistant, corrosion-resistant, low in cost, low in energy consumption and environment-friendly.
(3) The resin material of the invention can be regenerated after being washed by carboxylic acid, has simple preparation process, convenient operation, repeated use and no other impurities, has low cost, has strong adsorption potential of nontoxic carboxyl functional groups, and can effectively remove fluorine ions.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following description is made with reference to the preferred embodiments of the present invention and the accompanying detailed drawings.
Drawings
In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which
FIG. 1 shows the results of the fluorine content test of the modified resin prepared in example 2 after treating wastewater containing different interfering ions;
FIG. 2 shows the results of the fluorine content test of effluent water obtained by 30 times of adsorption regeneration of the modified resin prepared in example 4.
Detailed Description
The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.
Example 1
(1) 2g chloromethyl polystyrene resin added to 0.5g aluminum chloride, 2g phosphorus chloride in 100mL aqueous solution, at 0 degrees C stirring for 12 hours after filtering, deionized water washing 3 times.
(2) 2mol of Ce (NO)3)3Dissolving in a mixed solution of ethanol and water at a volume ratio of 1:1, and stirring at room temperature for 10 min.
(3) Adding the resin into the nitrate solution, distilling at 100 ℃ under reduced pressure for 8h, filtering the redundant solution, adding 40mL of 20% acetic anhydride, and stirring at room temperature for 3 h.
(4) The excess mixed solution was filtered, washed to neutrality with deionized water, and dried in an oven at 60 ℃.
And (3) testing the defluorination performance effect:
5mL of the modified resin of example 1 was taken and placed in 3 of the same containersIn a 100mL beaker. Respectively taking fluorine-containing wastewater (hydrochloric acid concentration is 15%, fluorine-containing C) in hydrochloric acidF2000ppm) and waste water containing fluorine in sulfuric acid (sulfuric acid concentration 15%, C)F2000ppm) and waste water containing fluorine in nitric acid (nitric acid concentration 15%, C)F- (2000 ppm) 25mL each was added to the above 3 beakers. Stirring was continued in a temperature-controlled constant temperature shaker for 3 hours at a stirring speed of 500 rpm. After the adsorption was completed, the adsorbent was separated from the fluorine-containing wastewater using filter paper. The change in fluoride concentration in the batch solution was measured using a fluoride ion selective electrode (Retzen PHS-3C type pH meter). The results of the fluoride concentration changes of the treated fluorine-containing wastewater with different inorganic acids are shown in Table 1.
TABLE 1 treatment results of fluorine-containing wastewater with different inorganic acids
As can be seen from Table 1, after the fluorine-containing wastewater containing different inorganic acids was treated with the modified resin prepared in example 1, the fluoride concentration of the fluorine-containing wastewater in hydrochloric acid was reduced by 99%, the fluoride concentration of the fluorine-containing wastewater in sulfuric acid was reduced by 98.25%, and the fluoride concentration of the fluorine-containing wastewater in nitric acid was reduced by 97.9%.
Example 2
(1) 6g chloromethyl polystyrene resin added to 0.5g aluminum chloride, 5g phosphorus chloride in 100mL aqueous solution, at 10 degrees C under stirring for 10 hours after filtering, deionized water washing 3 times.
(2) Adding 3mol of Zr (SO)4)2Dissolved in 2% sulfuric acid solution and stirred at room temperature for 10 min.
(3) Adding the resin into the sulfate solution, distilling at 80 ℃ under reduced pressure for 7h, filtering the redundant solution, adding 50mL of 40% acetic anhydride, and stirring at 30 ℃ for 2 h.
(4) The excess mixed solution was filtered, washed to neutrality with deionized water, and dried in an oven at 80 ℃.
And (3) testing the defluorination performance effect:
5mL of the modified resin of example 2 was taken and put into 7 identical 100mL beakers. Respectively taking out the metal cations (Fe) containing different metals2+、Cu2+、Mn2+、Ni2+、Na+、K+、Mg2+) Sulfuric acid (sulfuric acid concentration 15%, C)F- (2000 ppm) 25mL each was added to the above 7 beakers. Stirring was continued in a temperature-controlled constant temperature shaker for 3 hours at a stirring speed of 500 rpm. After the adsorption was completed, the adsorbent was separated from the fluorine-containing wastewater using filter paper. The change in fluoride concentration in the batch solution was measured using a fluoride ion selective electrode (Retzen PHS-3C type pH meter). The results of the fluoride concentration changes of effluent containing different interfering metal ions are shown in FIG. 1.
As can be seen from FIG. 1, the fluoride concentration of the effluent is 35ppm when no interfering ions exist, the recovery rate reaches 98.25%, the fluoride concentration of the effluent is kept between 35ppm and 50ppm under the condition that different metal cations exist, and the recovery rate of the fluoride reaches more than 97%, which shows that the modified resin prepared by the method has high stability, is less affected by the interfering ions and has high fluorine removal efficiency.
Example 3
(1) 4g chloromethyl polystyrene resin added to 2g aluminum chloride, 7g phosphorus chloride in 120mL aqueous solution, at 25 degrees C stirring for 8 hours after filtering, deionized water washing 3 times.
(2) 4mol of CeCl3Dissolved in 8% hydrochloric acid solution and stirred at room temperature for 10 min.
(3) Adding the resin into the hydrochloric acid salt solution, distilling at 100 ℃ under reduced pressure for 5h, filtering the redundant solution, adding 30mL of 10% oxalic anhydride, and stirring at 40 ℃ for 3 h.
(4) And filtering the redundant mixed solution, washing the mixed solution to be neutral by deionized water, and drying the mixed solution in an oven at 100 ℃.
And (3) testing the defluorination performance effect:
5mL of the modified resin of example 3 was taken and placed in a 100mL beaker. 10mL of fluorine-containing wastewater (hydrochloric acid concentration 20%, fluorine-containing 0.15%) of A. Anhui, Metal materials Ltd was added to the beaker. Stirring was continued in a temperature-controlled constant temperature shaker for 3 hours at a stirring speed of 500 rpm. After the adsorption was completed, the adsorbent was separated from the fluorine-containing wastewater using filter paper. The change in fluoride concentration in the solution was measured using a fluoride ion selective electrode (Retzen PHS-3C type pH meter). The results of the fluoride concentration change test are shown in table 2.
TABLE 2 fluoride concentration Change test results
As shown in Table 2, the modified resin prepared in example 3 exhibited a fluoride adsorption amount of 99.5% or more.
Example 4
(1) 4g chloromethyl polystyrene resin added to 0.5g aluminum chloride, 5g phosphorus chloride in 80mL aqueous solution, at 8 degrees C under stirring for 6-12 hours after filtering, deionized water washing 3 times.
(2) 2mol of Al (NO)3)3Dissolved in 20% acetic acid solution and stirred at room temperature for 10 min.
(3) Adding the resin into the nitrate solution, distilling at 60 ℃ under reduced pressure for 3h, filtering the redundant solution, adding 40mL of 25% oxalic anhydride, and stirring at 80 ℃ for 2 h.
(4) The excess mixed solution was filtered, washed to neutrality with deionized water, and dried in an oven at 80 ℃.
And (3) testing the effect of the circulation stability performance:
5mL of the modified resin of example 4 was loaded into a glass column, and the aspect ratio was 3: 1, the flow rate is 1BV/H, 5mL of fluoride wastewater (raw water C) is pumped in by a peristaltic pumpF1000ppm, adjusting the fluoride waste water pH to 1). After every 20BV of the fluorine-containing wastewater is adsorbed, 0.1M acetic acid 1BV is used for desorption (2BV/H), and the adsorption process is repeated to test the relative stability. The change in fluoride concentration in the solution was measured using a fluoride ion selective electrode (Retzen PHS-3C type pH meter). The results are shown in FIG. 2.
As can be seen from FIG. 2, the fluoride concentration of the effluent water is maintained at 2-4ppm during 30 times of adsorption regeneration, and the recovery rate of fluoride reaches more than 99%.
The resin material prepared by the method has the fluoride recovery rate of over 95 percent, is not influenced by interference ions, is easy to clean, acid-resistant, alkali-resistant and corrosion-resistant, can be regenerated after acid washing, has simple preparation process and simple operation, can be repeatedly used, and is environment-friendly and economical.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.
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