阅读说明：本技术 一种利用特种矮床酸阻滞树脂高效回收电极箔废酸的方法 (Method for efficiently recovering electrode foil waste acid by using special short bed acid retardation resin ) 是由 左选凤 居银栋 朱芬 黄珊 朱松峰 陈炎彬 黄莉君 于 2019-10-14 设计创作，主要内容包括：本发明公开了一种利用特种矮床酸阻滞树脂高效回收电极箔废酸的方法。该回收方法包括如下步骤：过滤除杂；填充活化：将特种酸阻滞树脂填充满矮床分离器的吸附柱,逆流注入活化剂浸泡,纯水顺流洗净盐分；高效分离：在柱内负压状态下,将除杂废酸液逆流经活化后的矮床分离器,游离酸被树脂颗粒选择性吸附,铝离子流出树脂床；洗脱再生：保持柱内负压,纯水顺流梯度洗脱阻滞酸,即得稀酸溶液。本发明针对电极箔废酸的处理引入矮床酸阻滞技术,结合特种酸阻滞树脂和特定矮床分离器,实现了电极箔废酸中铝、酸高效分离,工艺整体酸阻滞率最高可达95％以上,在柱内负压条件下进行酸阻滞与洗脱再生,增大了树脂吸附及再生过程通量,增加了回收酸的浓度。(The invention discloses a method for efficiently recovering electrode foil waste acid by using special short bed acid retardation resin. The recovery method comprises the following steps: filtering to remove impurities; filling and activating: filling the adsorption column of the short bed separator with special acid retardation resin, injecting an activating agent in a counter-current manner for soaking, and washing the salt with pure water in a forward-current manner; efficient separation: in the negative pressure state in the column, the impurity-removing waste acid liquid is reversely flowed through an activated short bed separator, the free acid is selectively adsorbed by the resin particles, and the aluminum ions flow out of the resin bed; elution and regeneration: keeping the negative pressure in the column, and carrying out pure water downstream gradient elution to block acid to obtain the dilute acid solution. The invention introduces short bed acid retardation technology aiming at the treatment of the electrode foil waste acid, combines special acid retardation resin and a special short bed separator, realizes the high-efficiency separation of aluminum and acid in the electrode foil waste acid, has the whole acid retardation rate of the process up to more than 95 percent, performs acid retardation and elution regeneration under the condition of negative pressure in a column, increases the flux of resin adsorption and regeneration processes, and increases the concentration of recovered acid.)

1. A method for efficiently recovering electrode foil waste acid by using special short bed acid retardation resin is characterized by comprising the following steps:

s1, filtering and removing impurities: filtering to remove coarse particles and suspended matter impurities in the electrode foil waste acid to obtain impurity-removed waste acid liquid;

s2, filling and activating: filling an adsorption column of a short bed separator with special acid-retarded resin, injecting an activating agent in a countercurrent manner, soaking for 2-4 h, continuously adding new resin after the resin is shrunk until the adsorption column is filled, sealing the short bed separator, flushing the adsorption column with pure water in a downstream manner, cleaning the activating agent on the adsorption column, and expanding the resin to a full bed compaction state;

s3, efficient separation: in the negative pressure state in the column, the impurity-removing waste acid solution in the S1 is subjected to countercurrent flow through an activated short bed separator, free acid is selectively adsorbed by resin particles, aluminum ions flow out of the resin bed until the adsorption capacity of the short bed separator is nearly saturated, and an aluminum-containing solution is collected;

s4, elution regeneration: keeping the negative pressure in the column, making the pure water flow through the S3 to the saturated short bed separator, gradient eluting the retarded acid on the resin particles to obtain the dilute acid solution, and reusing the regenerated special acid retarded resin in the step S3.

2. The method for efficiently recovering the electrode foil waste acid by using the special short bed acid retardation resin as claimed in claim 1, wherein the special acid retardation resin in S2 is a strong-base fine anion exchange resin, and the particle size of the special acid retardation resin is 0.2-0.4 mm.

3. The method for efficiently recovering the electrode foil waste acid by using the special short bed acid retardation resin as claimed in claim 1, wherein the diameter/height ratio of an adsorption column of the short bed separator in S2 is (1.5-3.5): 1.

4. the method for efficiently recovering the electrode foil waste acid by using the special short bed acid retardation resin as claimed in claim 1, wherein the countercurrent flow velocity of the impurity removal waste acid solution in S3 is 5-10 BV/h.

5. The method for efficiently recovering the electrode foil waste acid by using the special short bed acid retardation resin as claimed in claim 4, wherein the pure water downstream flow rate in S4 is 5-8 BV/h.

6. The method for efficiently recovering the electrode foil waste acid by using the special short bed acid retardation resin as claimed in claim 5, wherein the amount of the pure water used in S4 is 1-2 BV.

7. The method for efficiently recovering the electrode foil waste acid by using the special short bed acid retardation resin as claimed in claim 1, wherein the negative pressure in the column in S3 and S4 is-0.1 to-0.2 MPa.

8. The method for efficiently recycling the waste acid from the electrode foil by using the special short bed acid retardation resin as claimed in any one of claims 1 to 7, wherein the waste acid from the electrode foil is one or more of aluminum-containing hydrochloric acid, sulfuric acid or nitric acid.

9. The method for high-efficiency recovery of electrode foil waste acid by using special type dwarf acid retardant resin as claimed in claim 8, wherein the aluminum content of the electrode foil waste acid in S1 is Al³⁺1.0-3.0% in terms of acidity H⁺The amount is 3 to 5 mol/L.

Technical Field

The invention relates to the technical field of electrode foil waste acid recovery, in particular to a method for efficiently recovering electrode foil waste acid by using special short bed acid retardation resin.

Background

The electrode foil is a key part of an aluminum electrolytic capacitor, a high value-added product taking high-purity aluminum foil as a main raw material is used, the production process of the electrode foil mainly comprises two working procedures of corrosion and formation, and the purpose of corrosion is to carry out high-concentration H₂SO₄、HCl、HNO₃And under the action of the mixed acid, orderly etching pits are formed on the surface of the high-purity optical foil to increase the surface area of the electrode, so that the capacitance of the finished foil is increased. In this process, H in the bath is etched⁺Is continuously consumed and is replaced by Al³⁺In order to maintain the chemical composition of the bath solution in the etching bath stable, fresh acid solution must be continuously added to the etching bath to replace part of the used bath solution, thereby causing a large amount of acid consumption and waste acid generation. Therefore, the electrode foil waste acid contains a large amount of unconsumed acid and a certain amount of aluminum resources, and if the electrode foil waste acid is simply treated, the production and treatment costs of enterprises are increased, and the electrode foil waste acid is also a serious waste of resources. At present, the prior art on electrode foil waste acid recovery in the market mainly comprises a diffusion dialysis method, a concentration crystallization method, an extraction separation method and the like, but due to technical limitations, the methods are not widely popularized and applied. In contrast, the current mature industrialized resource recycling technology in China is mainly transferred to the hazardous waste disposal units in the region for comprehensive utilization and preparation of the aluminum water purification material, but along with the comprehensive utilization and preparation of the aluminum water purification materialThe national environmental protection situation is severe day by day, the actual requirements of increasingly strict environmental protection policies are difficult to meet by the existing industrial technology, and the disposal industry faces technical barriers due to the high risk and complexity of hazardous wastes. In recent years, the country greatly encourages the transformation of the hazardous waste disposal industry to a high-tech and intelligent equipment direction, and a competent enterprise can establish a disposal facility by itself, so that the reduction, harmlessness and recycling of hazardous wastes are realized from the source, the maximum regeneration and recovery of resources are promoted, the effective utilization rate of market resources is improved, and the long-term win-win situation of a hazardous waste production-consumption enterprise is realized.

Regarding the treatment of waste acid from electrode foil corrosion, the prior art CN108862348A discloses a method for recycling waste sulfuric acid from electrode foil corrosion, which prepares an aluminum sulfate product by preheating, evaporation, sulfuric acid supplementation, cooling, condensation crystallization, filter pressing and separation, the whole recycling process is long, preheating, evaporation, condensation crystallization are required, energy consumption is high, sulfuric acid is required to be supplemented externally, the risk is high, and the overall acid recycling rate of the process is also to be improved. The short bed acid retardation technology can realize the normal temperature recovery of waste acid, and avoid heat treatment such as preheating, evaporation or condensation, etc., although the short bed acid retardation technology also has related application examples on the treatment or recovery of waste acid in other industries or fields, such as the separation and recovery of iron and acid resources in iron-containing waste acid in the titanium white industry, the technology has limited adsorption and regeneration flux, long working period, large regeneration water consumption under normal pressure, and the concentration of recovered acid and the recovery efficiency of acid are also required to be improved. Therefore, the need of the art is to provide an economical, energy-saving, environment-friendly and simple method for efficiently recycling electrode foil corrosion waste acid, so as to further improve the current situation of poor recycling effect of electrode foil waste acid resources.

Disclosure of Invention

The invention aims to solve the technical problems of poor recovery effect and long treatment period of the conventional electrode foil corrosion waste acid, and provides a method for efficiently recovering the electrode foil waste acid by using special short bed acid retardation resin.

The above purpose of the invention is realized by the following technical scheme:

a method for efficiently recovering electrode foil waste acid by using special short bed acid retardation resin comprises the following steps:

s1, filtering and removing impurities: filtering to remove coarse particles and suspended matter impurities in the electrode foil waste acid to obtain impurity-removed waste acid liquid;

s2, filling and activating: filling an adsorption column of a short bed separator with special acid-retarded resin, injecting an activating agent in a countercurrent manner, soaking for 2-4 h, continuously adding new resin after the resin is shrunk until the adsorption column is filled, sealing the short bed separator, flushing the adsorption column with pure water in a downstream manner, cleaning salt on the adsorption column, and expanding the resin to a full bed compaction state;

s3, efficient separation: in the negative pressure state in the column, the impurity-removing waste acid solution in the S1 is subjected to countercurrent flow through an activated short bed separator, free acid is selectively adsorbed by resin particles, aluminum ions flow out of the resin bed until the adsorption capacity of the short bed separator is nearly saturated, and an aluminum-containing solution is collected;

s4, elution regeneration: keeping the negative pressure in the column, making the pure water flow through the S3 to the saturated short bed separator, gradient eluting the retarded acid on the resin particles to obtain the dilute acid solution, and reusing the regenerated special acid retarded resin in the step S3.

Wherein, it is required to be noted that:

in S1, coarse particles and suspended impurities in the electrode foil waste acid are removed by filtering and impurity removal, so that the particles and impurities are prevented from entering a short bed separator, blocking the pores of a rotary water distributor, a water combing grate plate and filter cloth and polluting resin.

S2, an activating agent used for activation can be 10% NaCl solution, the effect of soaking the special acid retardation resin is to remove soluble impurities, mechanical impurities and broken resin in the resin, meanwhile, the volume of the resin can be reduced, so that more resin can be filled in the adsorption column, after pure water is used for cleaning salt, the resin in the column can absorb water to expand and finally reach a full bed compaction state, and the subsequent acid retardation and acid stripping effects are prevented from being influenced by gaps among the resin and surrounding air or bubbles.

The short bed separator in S2 comprises an upper semi-arc cover plate, a lower semi-arc cover plate, a rotary water distributor, an adsorption column, an upper water combing grate plate, a lower water combing grate plate and filter cloth, wherein the aperture of the rotary water distributor is less than or equal to 0.1mm, the aperture of the water combing grate plate is 0.5-1.0 mm, and the aperture of the filter cloth is 50-100 mu m.

The invention introduces short bed acid retardation technology aiming at the treatment of the electrode foil waste acid, realizes the high-efficiency separation of aluminum and acid in the electrode foil waste acid by using special acid retardation resin and a special short bed separator, and the overall acid retardation rate of the process can reach more than 95 percent at most.

The aluminum-containing solution obtained by the separation of the invention can be used for preparing aluminum water purifying agents.

Preferably, the special acid retardation resin in S2 is a strong-base fine anion exchange resin, and the particle size of the special acid retardation resin is 0.2-0.4 mm. For example, the special acid retardation resin of the invention can be selected from Tulsion A-853EFine mesh type strong-alkaline fine type anion exchange resin.

More preferably, the specific acid-blocking resin in S2 is a strongly basic fine type anion exchange resin having a particle size of 0.2 mm.

Effect of resin particle size on separation: the particle size of the resin particles is relatively small, the specific surface area is larger, so that the exchange kinetics is greatly improved, the contact adsorption is more sufficient when acid blocks, and the aluminum-acid separation effect is better.

Preferably, the diameter/height ratio of the adsorption column of the short bed separator in S2 is (1.5-3.5): 1. for example, it may be 1.5:1, 2.5:1 or 3.5:1, preferably 2.5: 1.

Influence of adsorption column diameter/height ratio on separation: in the short bed process, maintaining the proper diameter/height ratio of the adsorption column can reduce the height of the inactive area of the resin, more effectively utilize the remaining resin, and reduce the pressure drop and the equipment size. Meanwhile, when the depth of the mass transfer area is reduced to a certain range, the reaction kinetics can be effectively increased.

Preferably, the countercurrent flow velocity of the impurity-removing waste acid liquid in the S3 is 5-10 BV/h. For example, it may be 5BV/h, 8BV/h or 10BV/h, preferably 8 BV/h.

When acid retardation operation is carried out, the flow rate of the impurity-removing waste acid solution is controlled as follows: during acid retardation operation, the flow rate of the waste acid liquor is too low, so that the reaction process is too slow, the working period is too long, and the acid retardation function of the short bed separator is not embodied and optimally utilized to the maximum extent; too large flow velocity of waste acid liquid can cause too short retention time and too late absorption, the acid retardation effect is poor, and aluminum and acid resources cannot be efficiently separated.

Preferably, the pure water downstream flow rate in S4 is 5-8 BV/h. Wherein the pure water downstream flow rate is preferably 5BV/h for better elution effect.

The reason why the flow rate of pure water is controlled when the acid elution operation is performed is as follows: when the acid elution is carried out, the flow rate of pure water is too low, so that the elution process is too slow and the period is too long; the flow rate of pure water is too large, so that the elution effect is poor, the water consumption in the elution process is large, and the concentration of the recovered acid is lower due to the dilution effect.

Preferably, the amount of the pure water used in S4 is 1-2 BV. Wherein, in order to ensure the resin regeneration to be complete and not to influence the secondary use, the using amount of the pure water is preferably 2 BV.

The reason why the amount of pure water is controlled when the acid elution operation is performed is as follows: the same acid-washing effect is achieved, and the lower the pure water consumption is, the higher the concentration of the recovered acid is, and the lower the comprehensive utilization cost of the subsequent resources is, the higher the value is.

Preferably, the negative pressure in the column in S3 and S4 is-0.1 to-0.2 MPa, preferably-0.2 MPa.

The reasons for controlling the negative pressure in the column when carrying out acid retardation and acid stripping operations are as follows: and certain negative pressure in the column is kept to prevent air from entering the adsorption column or generating bubbles in gaps of the resin and around the adsorption column during operation, so that the waste acid liquid or pure water cannot be in full contact with the resin particles, and the final effects of acid retardation and acid stripping are influenced. Meanwhile, certain negative pressure in the column is beneficial to increasing the flux of the resin adsorption and regeneration process, accelerating the reaction process, shortening the working period, reducing the water consumption in the regeneration process and increasing the concentration of the recovered acid. However, the negative pressure in the column cannot be too large, and after a certain limit is exceeded, the retention time of the waste acid liquid or the pure water in the adsorption column is too short in the operation process, so that the ideal acid retardation or acid stripping effect cannot be achieved.

Preferably, the electrode foil waste acid is one or more of aluminum-containing hydrochloric acid, sulfuric acid or nitric acid.

Preferably, the aluminum content (in Al) of the electrode foil waste acid in S1³⁺Calculated) is 1.0 to 3.0 percentAcidity (in H)⁺In terms of) is 3 to 5 mol/L. The method for recycling the waste acid of the electrode foil can be applied to treating the waste acid solution of the electrode foil with various aluminum contents and acidity, and is particularly suitable for treating the common waste acid with the aluminum content of 1.0-3.0% and the acidity of 3-5 mol/L.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention provides a method for efficiently recovering electrode foil waste acid by using special short bed acid retardation resin, which introduces a short bed acid retardation technology aiming at the treatment of the electrode foil waste acid, realizes the efficient separation of aluminum and acid in the electrode foil waste acid by using the special acid retardation resin and combining a special short bed separator, and has the highest overall acid retardation rate of the process of more than 95 percent;

(2) the recovery method of the invention carries out acid retardation and elution regeneration under the condition of negative pressure in the column, increases the flux of the resin adsorption and regeneration process, shortens the working period, reduces the energy consumption of flow transportation, reduces the water consumption in the regeneration process and increases the concentration of the recovered acid;

(3) the regenerated and recovered aluminum and acid resources are concentrated and recycled, the electrode foil waste acid resources are pushed to be recycled to the maximum extent, and the effective utilization rate of market resources is improved.

Detailed Description

The present invention will be further described with reference to specific embodiments, but the present invention is not limited to the examples in any way. The starting reagents employed in the examples of the present invention are, unless otherwise specified, those that are conventionally purchased.

The basic chemical properties of the electrode foil waste acid of the present invention are shown in table 1.

TABLE 1 basic chemistry of the raw materials

Raw materials	Aluminum content (in terms of Al)3+Calculated)/	Acidity (in H)+meter)/(mol/L)
			Electrode foil waste acid	2.54	4.65