Method for separating and recycling acid and metal salt in aluminum profile pickling waste liquid

Abstract

The invention discloses a method for separating and recycling acid and metal salt in aluminum profile pickling waste liquid, which comprises the following steps: filling a sulfonic acid modified styrene-divinyl benzene copolymer serving as a solid-phase separation material into a separation column to obtain a chromatographic separation column; the method comprises the following steps: loading an aluminum profile pickling waste liquid containing sulfuric acid and aluminum sulfate to a chromatographic separation column, and adsorbing sulfuric acid and aluminum sulfate into a solid-phase separation material; pure water is adopted to elute the chromatographic separation column, and eluent is collected in two sections, so that sulfuric acid and aluminum sulfate are obtained through separation. The recovery rate of sulfuric acid is more than 95% and the recovery rate of aluminum sulfate is more than Compared with an existing aluminum profile pickling waste liquid separation process, the method has the advantages of being easy to operate, mild in reaction condition, high in economic benefit, high in reaction efficiency and simple in equipment requirement.

Description

Technical Field

[0001] The invention belongs to the technical field of waste acid resource treatment, and specifically relates to a method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid. Background Art

[0002] With the continuous advancement of the aluminum profile industry in my country and around the world, the amount of waste acid generated by anodizing is increasing. Faced with energy shortages, resource shortages and severe environmental pollution, environmental protection has become a global issue that has attracted the attention of the whole society and all mankind. The direct discharge of waste acid not only wastes resources and pollutes the environment, but also threatens human health. In order to protect the environment and human survival, and to recycle useful substances and rationally recycle resources to promote sustainable development, it is essential to recycle and reuse acid waste liquid.

[0003] The neutralization method is mainly used for the treatment of metal waste acid, which is costly and produces secondary pollution. Other treatment methods include roasting, ion exchange resin, membrane separation, concentration and impurity removal, extraction, chemical conversion, etc., which create economic and environmental benefits by utilizing waste acid resources, and have obvious advantages over the neutralization method. The Chinese government is committed to strengthening environmental protection and promoting green development. It has put forward strict requirements on the discharge of waste acid, which will prompt enterprises to invest more actively in the field of waste acid recovery and treatment. In addition, aluminum profile pickling waste liquid contains various metals, acidic substances and other resources. By recycling these substances, it can not only reduce the demand for primary resources, but also help improve resource utilization efficiency. In the case of resource shortage, waste acid recovery has become an important sustainable development method. There is still a huge market size for the recycling and treatment of aluminum profile pickling waste liquid, and it is expected that the market demand for its recycling and treatment will continue to increase in the next few years.

[0004] At present, various methods for treating aluminum profile pickling wastewater have their advantages and disadvantages: the ion exchange resin method has a short process flow, is easy to operate, and has low energy consumption, but the concentration of the recovered inorganic acid is low during room temperature treatment, and high-concentration new acid must be added before it can be used; the membrane separation method has a small processing capacity, and the concentration of the recovered acid is limited by the equilibrium concentration, and the residual liquid after recovery cannot be discharged directly; the roasting method does not produce new pollutants, and the recovered products can be recycled, which improves environmental protection; although the concentration method equipment is easy to scale and difficult to clean, the acid treated by this method can reach a higher concentration and can be used by spraying; the extraction method can separate metal ions from the acid under certain conditions, but the treated waste acid still contains a large amount of organic matter. Summary of the invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a new resource recovery method for aluminum profile pickling liquid in view of the shortcomings of the prior art, which realizes the full resource recovery of sulfuric acid and sulfate in waste acid through sulfuric acid separation and aluminum sulfate enrichment.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows: A method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid comprises the following steps: (1) filling a sulfonic acid-modified styrene-divinylbenzene copolymer as a solid phase separation material into a separation column to obtain a chromatographic separation column; (2) loading the aluminum profile pickling waste liquid containing sulfuric acid and aluminum sulfate onto the chromatographic separation column obtained in step (1), and adsorbing the sulfuric acid and aluminum sulfate into the solid phase separation material; (3) The chromatographic separation column of step (2) is eluted with pure water, and the eluate is collected in two sections, thereby separating sulfuric acid and aluminum sulfate.

[0007] Specifically, in step (1), the sulfonic acid-modified styrene-divinylbenzene copolymer has a styrene-divinylbenzene copolymer as a skeleton structure, and the terminal of the styrene-divinylbenzene copolymer is a sulfonic acid structure. Preferably, the molar content of the sulfonic acid structure in the solid phase separation material is 10-15%.

[0008] Specifically, in step (1), the preparation method of the sulfonic acid-modified styrene-divinylbenzene copolymer is as follows: The polymer microspheres are synthesized by a seed swelling method using styrene and diethylene as monomers, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and triallyl isocyanurate as crosslinking agents and a toluene-isopropanol mixed system as a pore-forming agent; then they are hydrolyzed in a sodium hydroxide environment and finally reacted with β-cyclodextrin in an epichlorohydrin environment to finally form polymer adsorption microspheres with sulfonic acid groups in the skeleton and multi-hydroxyl structures on the surface.

[0009] Preferably, in step (1), the particle size of the solid phase separation material is 20-100 μm.

[0010] Specifically, in step (1), the solid phase separation material is ultrasonically dispersed in water, the dispersion is added to the column barrel by a wet column packing method, the column packing pressure is controlled at 2-3 MPa, and the column is rinsed with pure water until there is no turbidity, thereby obtaining a chromatographic separation column.

[0011] Preferably, in step (2), in the aluminum profile pickling waste liquid, the mass concentration of sulfuric acid is 5-50wt%, and the mass concentration of aluminum sulfate is 1-10wt%.

[0012] Preferably, in step (2), the loading flow rate of the aluminum profile pickling waste liquid is 0.1-10 BV / min.

[0013] Specifically, in step (3), pure water is used to elute the chromatographic separation column in step (2), and the first eluent is collected at the same time until the mass concentration of sulfuric acid in the eluent is reduced to 2%, thereby separating and obtaining sulfuric acid.

[0014] Furthermore, in step (3), the chromatographic separation column is continuously eluted with pure water, and the first eluent is collected at the same time, until the mass concentration of sulfuric acid in the eluent is reduced to 1%, thereby obtaining an aluminum sulfate solution containing a small amount of sulfuric acid.

[0015] Furthermore, in step (3), the obtained aluminum sulfate containing a small amount of sulfuric acid is further deacidified and concentrated to separate and obtain aluminum sulfate.

[0016] Specifically, the time for collecting the eluent in the two stages of the present invention is 5 to 30 minutes.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) The present invention develops a novel method for recycling aluminum profile pickling liquid, using sulfonic acid-modified styrene-divinylbenzene copolymer as a chromatographic solid phase adsorption material, and realizing full resource recovery of sulfuric acid and sulfate in waste acid through sulfuric acid separation and aluminum sulfate enrichment. It has the advantages of low cost and high efficiency, and provides impetus for the further development of metal waste acid recovery and treatment.

[0019] (2) The solid phase separation material prepared by the present invention adsorbs sulfuric acid and aluminum sulfate by retardation, and separates hydrogen ions and metal ions by using the different diffusion speeds in the separation column. The sulfuric acid recovery rate is greater than 95%, and the aluminum sulfate recovery rate is greater than 97%. Compared with the existing aluminum profile pickling waste liquid separation process, the method described in the present invention has the advantages of simple operation, mild reaction conditions, high economic benefits, high reaction efficiency and simple equipment requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0021] Figure 1 The present invention is a flow chart for preparing the sulfonic acid modified styrene-divinylbenzene copolymer solid phase separation material.

[0022] Figure 2 This is a scanning electron microscope photograph of the sulfonic acid-modified styrene-divinylbenzene copolymer solid phase separation material of the present invention.

[0023] Figure 3 The present invention is a schematic diagram of the principle of separating the aluminum profile pickling waste liquid by the chromatography method. DETAILED DESCRIPTION

[0024] The present invention can be better understood with reference to the following examples.

[0025] like Figure 1 As shown, the sulfonic acid modified styrene-divinylbenzene copolymer of the present invention has the styrene-divinylbenzene copolymer as the skeleton structure, the terminal of the styrene-divinylbenzene copolymer is the sulfonic acid structure, and the molar content of the sulfonic acid structure is 10-15%.

[0026] The preparation method of the sulfonic acid-modified styrene-divinylbenzene copolymer of the present invention is as follows: The polymer microspheres are synthesized by a seed swelling method using styrene and diethylene as monomers, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and triallyl isocyanurate as crosslinking agents and a toluene-isopropanol mixed system as a pore-forming agent; then they are hydrolyzed in a sodium hydroxide environment and finally reacted with β-cyclodextrin in an epichlorohydrin environment to finally form polymer adsorption microspheres with sulfonic acid groups in the skeleton and multi-hydroxyl structures on the surface.

[0027] Combination Figure 2 As shown, the obtained polymer adsorption microspheres have uniform particle size and good stability, which can greatly improve the separation rate and shorten the separation time. Example 1

[0028] A certain amount of sulfonic acid-modified styrene-divinylbenzene copolymer was used as a solid phase separation material (sulfonic acid structure content of 13.45%, particle size of 20 microns), placed in 500 mL of water and ultrasonically vibrated for 15 minutes. Subsequently, 300 mL of the dispersion was added to the column (DAC dynamic column DAC50) by wet column packing method to ensure that there were no bubbles. The column packing pressure was 2.5 MPa, and 3 BV of pure water was used to rinse until there was no turbidity, and a chromatographic separation column C-20 was prepared. Example 2

[0029] A certain amount of sulfonic acid-modified styrene-divinylbenzene copolymer was used as a solid phase separation material (sulfonic acid structure content of 13.45%, particle size of 50 microns), placed in 500 mL of water and ultrasonically vibrated for 15 minutes. Subsequently, 300 mL of the dispersion was added to the column (DAC dynamic column DAC50) by wet column packing method to ensure that there were no bubbles. The column packing pressure was 2.5 MPa, and 3 BV of pure water was used to rinse until there was no turbidity, and a chromatographic separation column C-50 was prepared. Example 3

[0030] A certain amount of sulfonic acid-modified styrene-divinylbenzene copolymer was used as a solid phase separation material (sulfonic acid structure content of 13.45%, particle size of 100 microns), placed in 500 mL of water and ultrasonically vibrated for 15 minutes. Subsequently, 300 mL of the dispersion was added to the column (DAC dynamic column DAC50) by wet column packing method to ensure that there were no bubbles. The column packing pressure was 2.5 MPa, and 3 BV of pure water was used to rinse until there was no turbidity, and a chromatographic separation column C-100 was prepared. Example 4

[0031] Take the waste pickling liquid of aluminum sulfate profiles containing 1wt% aluminum sulfate and 5wt% aluminum sulfate, load it into the C-20 chromatographic column at a speed of 0.6 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluent is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluent is reduced to 1%, and it is collected as an aluminum sulfate recovery area, and the total elution time is 10 min. Under this condition, the recovery rate of sulfuric acid is 98.2%, and the recovery rate of aluminum sulfate is 98.4%.

[0032] Combination Figure 3 As shown, the principle of the chromatography method for separating the aluminum profile pickling waste liquid of the present invention is to use the solid phase separation material to adsorb sulfuric acid and aluminum sulfate through retardation, and to achieve separation by utilizing the different diffusion rates of hydrogen ions and metal ions in the separation column. Example 5

[0033] Take the pickling waste liquid containing 5wt% aluminum sulfate and 30wt% aluminum sulfate, load it into the C-20 chromatographic column at a speed of 0.6 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluent is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluent is reduced to 1%, and it is collected as an aluminum sulfate recovery area, and the total elution time is 10 min. Under this condition, the recovery rate of sulfuric acid is 97.9%, and the recovery rate of aluminum sulfate is 98.2%. Example 6

[0034] Take the pickling waste liquid containing 10wt% aluminum sulfate and 50wt% aluminum sulfate, load it into the C-20 chromatographic column at a speed of 0.6 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluate is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluate is reduced to 1%, and it is collected as an aluminum sulfate recovery area. The total elution time is 10 min. Under this condition, the recovery rate of sulfuric acid is 97.3%, and the recovery rate of aluminum sulfate is 97.6%. Example 7

[0035] Take the pickling waste liquid containing 5wt% aluminum sulfate and 30wt% aluminum sulfate, load it into the C-20 chromatographic column at a speed of 0.1 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluate is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluate is reduced to 1%, and it is collected as an aluminum sulfate recovery area, and the total elution time is 10 min. Under this condition, the recovery rate of sulfuric acid is 99.2%, and the recovery rate of aluminum sulfate is 98.9%. Example 8

[0036] Take the pickling waste liquid containing 5wt% aluminum sulfate and 30wt% aluminum sulfate, load it into the C-20 chromatographic column at a speed of 10 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluent is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluent is reduced to 1%, and it is collected as an aluminum sulfate recovery area. The total elution time is 10 min. Under this condition, the recovery rate of sulfuric acid is 96.4%, and the recovery rate of aluminum sulfate is 96.1%. Example 9

[0037] Take the pickling waste liquid containing 10wt% aluminum sulfate and 50wt% aluminum sulfate, load it into the C-50 chromatographic column at a speed of 0.6 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluate is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluate is reduced to 1%, and it is collected as an aluminum sulfate recovery area. The total elution time is 10 min. Under this condition, the recovery rate of sulfuric acid is 97.2%, and the recovery rate of aluminum sulfate is 98.1%. Example 10

[0038] Take the pickling waste liquid containing 10wt% aluminum sulfate and 50wt% aluminum sulfate, load it into the C-100 chromatographic column at a speed of 0.6 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluent is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluent is reduced to 1%, and it is collected as an aluminum sulfate recovery area, and the total elution time is 10 min. Under this condition, the recovery rate of sulfuric acid is 91.2%, and the recovery rate of aluminum sulfate is 90.7%. Embodiment 11

[0039] Take the pickling waste liquid containing 10wt% aluminum sulfate and 50wt% aluminum sulfate, load it into the C-20 chromatographic column at a speed of 0.6 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluent is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluent is reduced to 1%, and it is collected as an aluminum sulfate recovery area. The total elution time is 5 min. Under this condition, the recovery rate of sulfuric acid is 94.4%, and the recovery rate of aluminum sulfate is 95.7%. Example 12

[0040] Take the pickling waste liquid containing 10wt% aluminum sulfate and 50wt% aluminum sulfate, load it into the C-20 chromatographic column at a speed of 0.6 BV / min, elute with pure water from the other end of the chromatographic column after loading, and collect the recovered effluent in two sections. Among them, the first section is until the mass concentration of sulfuric acid in the eluate is reduced to 2%, and it is collected as a sulfuric acid mixed liquid, and the second section is until the mass concentration of sulfuric acid in the eluate is reduced to 1%, and it is collected as an aluminum sulfate recovery area. The total elution time is 30 min. Under this condition, the recovery rate of sulfuric acid is 98.3%, and the recovery rate of aluminum sulfate is 98.8%.

[0041] The present invention provides a method and idea for separating and recovering acid and metal salt in aluminum pickling waste liquid. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid, characterized in that: The steps include: (1) filling a sulfonic acid-modified styrene-divinylbenzene copolymer as a solid phase separation material into a separation column to obtain a chromatographic separation column; (2) loading the aluminum profile pickling waste liquid containing sulfuric acid and aluminum sulfate onto the chromatographic separation column obtained in step (1), and adsorbing the sulfuric acid and aluminum sulfate into the solid phase separation material; (3) The chromatographic separation column of step (2) is eluted with pure water, and the eluate is collected in two sections, thereby separating sulfuric acid and aluminum sulfate.

2. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 1, characterized in that: In step (1), the sulfonic acid-modified styrene-divinylbenzene copolymer has a styrene-divinylbenzene copolymer as a skeleton structure, the end of the styrene-divinylbenzene copolymer is a sulfonic acid structure, and the molar content of the sulfonic acid structure is 10-15%.

3. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 1, characterized in that: In step (1), the preparation method of the sulfonic acid-modified styrene-divinylbenzene copolymer is as follows: The polymer microspheres are synthesized by a seed swelling method using styrene and diethylene as monomers, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid and triallyl isocyanurate as crosslinking agents and a toluene-isopropanol mixed system as a pore-forming agent; then they are hydrolyzed in a sodium hydroxide environment and finally reacted with β-cyclodextrin in an epichlorohydrin environment to finally form polymer adsorption microspheres with sulfonic acid groups in the skeleton and multi-hydroxyl structures on the surface.

4. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 1, characterized in that: In step (1), the particle size of the solid phase separation material is 20-100 μm.

5. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 1, characterized in that: In step (1), the solid phase separation material is ultrasonically dispersed in water, and the dispersion is added to the column barrel by a wet column packing method. The column packing pressure is controlled at 2-3 MPa, and the column is rinsed with pure water until there is no turbidity, thereby obtaining a chromatographic separation column.

6. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 1, characterized in that: In step (2), in the aluminum profile pickling waste liquid, the mass concentration of sulfuric acid is 5-50wt%, and the mass concentration of aluminum sulfate is 1-10wt%.

7. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 1, characterized in that: In step (2), the sample loading flow rate of the aluminum profile pickling waste liquid is 0.1-10 BV / min.

8. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 1, characterized in that: In step (3), pure water is used to elute the chromatographic separation column of step (2), and the first eluent is collected at the same time, until the mass concentration of sulfuric acid in the eluent is reduced to 2%, and sulfuric acid is separated.

9. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 8, characterized in that: In step (3), pure water is used to continue eluting the chromatographic separation column, and the first eluent is collected at the same time, until the mass concentration of sulfuric acid in the eluent is reduced to 1%, thereby obtaining an aluminum sulfate solution containing a small amount of sulfuric acid.

10. The method for separating and recovering acid and metal salt in aluminum profile pickling waste liquid according to claim 9, characterized in that: In step (3), the obtained aluminum sulfate solution containing a small amount of sulfuric acid is further deacidified and concentrated to separate aluminum sulfate.

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