Recycling method of electroplating liquid for integrated circuit

Abstract

The invention relates to the technical field of electroplating liquid regeneration, and particularly discloses a recycling method of electroplating liquid for an integrated circuit. The recycling method of the electroplating solution for the integrated circuit comprises the following steps: (1) enabling the electroplating solution to flow through copper ion selective adsorption resin at the flow speed of 14-16mL / min to obtain a mixed solution, eluting the copper ion selective adsorption resin after the adsorption capacity reaches 80%, and selecting sulfuric acid as an eluent to obtain an eluent; (2) adding a composite adsorbent, which is an activated carbon-zeolite composite adsorbent, into the mixed solution, adjusting the pH value to 4-6, stirring and oscillating for 6-7 hours, centrifuging, and filtering to obtain a filtrate; (3) mixing the eluent with the filtrate to prepare a regenerated electroplating solution; in addition, the preparation method has the advantage that the electroplating liquid for the integrated circuit can be recycled.

Description

Technical Field

[0001] This application relates to the technical field of electroplating solution regeneration, and more specifically, it relates to a method for recycling and regenerating electroplating solution for integrated circuits. Background Art

[0002] Electroplating solution is a crucial chemical solution in the electroplating process, which plays an irreplaceable role in the manufacturing industry, especially in the field of integrated circuits. Through the principle of electrolysis, electroplating technology deposits a thin layer on the surface of metals or other materials to improve their wear resistance, conductivity, and corrosion resistance. During the manufacturing process of integrated circuits, the integrated circuits need to go through an electroplating process to deposit a copper coating to improve their conductivity.

[0003] With the rapid development of the integrated circuit industry, the consumption of electroplating solution is increasing continuously, which also brings problems of resource consumption and environmental pollution. The electroplating solution contains various heavy metal ions and organic additives. If directly discharged without treatment, it will cause serious harm to the environment and human health. Therefore, the recovery and reuse of electroplating solution can not only reduce the emission and waste of heavy metals, but also recycle and save resources. Summary of the Invention

[0004] In order to enable the electroplating solution for integrated circuits to be recycled and regenerated, this application provides a method for recycling and regenerating electroplating solution for integrated circuits.

[0005] In the first aspect, this application provides a method for recycling and regenerating electroplating solution for integrated circuits, adopting the following technical solutions: A method for recycling and regenerating electroplating solution for integrated circuits includes the following steps: (1) Let the electroplating solution flow through a copper ion selective adsorption resin at a flow rate of 14 - 16 mL / min to obtain a mixed solution. After the adsorption amount reaches 80%, elute the copper ion selective adsorption resin. The eluent is sulfuric acid to obtain an eluate; (2) Add a composite adsorbent to the mixed solution and adjust the pH to 4 - 6. The composite adsorbent is an activated carbon zeolite composite adsorbent. After stirring and shaking for 6 - 7 h, centrifuge and filter to obtain a filtrate; (3) Mix the eluate and the filtrate to prepare a regenerated electroplating solution.

[0006] By adopting the above technical solution, the copper ion selective adsorption resin has good selective adsorption property for copper, can adsorb and enrich the copper ions in the electroplating solution, and is eluted with sulfuric acid, so that the copper ions in the electroplating solution are enriched in the eluent, and can provide copper ions for the regenerated electroplating solution. The composite adsorbent is an activated carbon zeolite composite adsorbent, which can remove zinc ions, iron ions and organic impurities in the mixed solution. The eluent is mixed with the filtrate, and after adjusting the pH to acidic, the copper ion concentration and pH are adjusted to regenerate the electroplating solution and put it into use.

[0007] Preferably, the preparation method of the activated carbon zeolite composite adsorbent includes the following steps: after mixing zeolite and activated carbon, adding a polyvinyl alcohol solution and then stirring, drying until the water content is 30 - 50%, extruding into a shape, and drying at 200 - 220 °C for 1 h to obtain the activated carbon zeolite composite adsorbent.

[0008] By adopting the above technical solution, polyvinyl alcohol has good viscosity. After mixing zeolite and activated carbon and adding a polyvinyl alcohol solution, it can effectively bond zeolite and activated carbon, making the zeolite activated carbon composite form an adsorbent, and adsorb and remove metal ions and organic impurities in the mixed solution.

[0009] Preferably, the mass ratio of the zeolite to the activated carbon is (0.8 - 1.1):(0.9 - 1.0).

[0010] By adopting the above technical solution, controlling the mass ratio of zeolite to activated carbon can make the adsorption effect of the two on zinc ions, iron ions and organic impurities in the mixed solution better, and the removal effect is better.

[0011] Preferably, the addition amount of the polyvinyl alcohol is 13 - 15 wt% of the activated carbon zeolite composite adsorbent.

[0012] By adopting the above technical solution, controlling the addition amount of polyvinyl alcohol enables good mixing and bonding of activated carbon and zeolite. If the addition amount is too small, the connection between activated carbon and zeolite is likely to be loose.

[0013] Preferably, the activated carbon undergoes the following pretreatment: placing the activated carbon at 500 - 550 °C for activation for 1 - 1.2 h, dissolving chitosan in a 2 wt% acetic acid solution, adding the activated carbon and mixing, ultrasonicating for 15 - 20 min, adding glutaraldehyde, and performing microwave irradiation for 4 - 5 min while stirring at 45 - 50 °C, and then washing successively with 0.1 mol / L sodium hydroxide solution, absolute ethanol and water, and drying at 80 °C to obtain chitosan-modified activated carbon.

[0014] By adopting the above technical solution, chitosan contains a relatively large number of hydroxyl and amino groups, which can coordinate and bind with metal ions such as iron ions and zinc ions, thereby realizing the adsorption of metal ions. At the same time, it can also adsorb iron ions and zinc ions through ion exchange and physical adsorption and other methods.

[0015] Preferably, the mass ratio of the activated carbon to the chitosan is (1.65 - 1.79):(1.62 - 1.67).

[0016] By adopting the above technical solution, controlling the mass ratio of the activated carbon to the chitosan enables the chitosan to be fully coated on the outer side of the activated carbon and crosslinked. Chitosan contains a relatively large number of hydroxyl and amino groups, which can react with the activated carbon under the action of glutaraldehyde. Chitosan has good viscosity and can adsorb organic impurities and the like in the flowing mixed liquid well. If the addition amount of chitosan is reduced, the coordination binding effect of chitosan is likely to decrease. If the addition amount of chitosan is too much, the adhesiveness is likely to be too large, resulting in the pores of the activated carbon being blocked, and its adsorption performance deteriorates.

[0017] Preferably, the chitosan undergoes the following pretreatment: Dissolve ascorbic acid in water, add chitosan and dissolve it, mix evenly, let it stand overnight, filter to obtain a filtrate, and then freeze-dry to obtain modified chitosan.

[0018] By adopting the above technical solution, the reaction product of chitosan and ascorbic acid can form chelates with metal ions, improving the binding strength between the modified chitosan and metal ions, reducing the reverse reaction in the adsorption process, and thus improving the adsorption effect.

[0019] Preferably, the zeolite undergoes the following treatment: Place the zeolite in a 15 - 17wt% sodium hydroxide solution, activate it for 12 - 13h, and then calcine and fix it at 400 - 420 °C to obtain activated zeolite.

[0020] By adopting the above technical solution, after the zeolite is treated with the sodium hydroxide solution, the impurities in the zeolite react with the alkali solution, so that the pores in the zeolite are dredged, increasing the number of mesopores and micropores in the zeolite, and thus improving the specific surface area and adsorption performance of the activated zeolite.

[0021] In summary, the present application has the following beneficial effects: 1. Since the copper ion selective adsorption resin used in the present application has good selective adsorption for copper, it can adsorb and enrich the copper ions in the electroplating solution and elute them with sulfuric acid, so that the copper ions in the electroplating solution are enriched in the eluate, which can provide copper ions for the regeneration of the electroplating solution. The composite adsorbent is an activated carbon - zeolite composite adsorbent, which can remove zinc ions, iron ions and organic impurities in the mixed liquid. The eluate and the filtrate are mixed, the pH is adjusted to be acidic, and then the copper ion concentration and pH are adjusted to regenerate the electroplating solution and put it into use.

[0022] 2. In this application, polyvinyl alcohol is used to bond activated carbon and zeolite. Polyvinyl alcohol has good viscosity. After mixing zeolite and activated carbon, polyvinyl alcohol solution is added. Polyvinyl alcohol has good adhesiveness and can effectively bond zeolite and activated carbon, enabling the formation of a zeolite-activated carbon composite adsorbent to adsorb and remove metal ions and organic impurities in the mixed solution.

[0023] 3. In this application, ascorbic acid reacts with chitosan. The reaction product of chitosan and ascorbic acid can form chelates with metal ions, enhancing the binding strength between the modified chitosan and metal ions, reducing the reverse reaction during the adsorption process, and thus improving the adsorption effect. Specific Embodiments

[0024] The following further elaborates on this application in conjunction with examples.

[0025] Preparation Examples 1 - 7 of Chitosan-Modified Activated Carbon Preparation Example 1 The activated carbon was activated at 500 °C for 1.2 h. Chitosan was dissolved in 90 mL of 2 wt% acetic acid solution with a chitosan concentration of 10.68 g / L. The activated carbon after activation was added and mixed. The mass ratio of activated carbon to chitosan was 1.65:1.62. After ultrasonic treatment for 15 min, 10 mL of glutaraldehyde was added, and microwave irradiation was carried out with stirring at 45 °C for 4 min. It was successively washed with 0.1 mol / L sodium hydroxide solution, absolute ethanol, and water, and dried at 80 °C to obtain chitosan-modified activated carbon.

[0026] Preparation Example 2 The activated carbon was activated at 550 °C for 1 h. Chitosan was dissolved in 120 mL of 2 wt% acetic acid solution with a chitosan concentration of 12.08 g / L. The activated carbon after activation was added and mixed. The mass ratio of activated carbon to chitosan was 1.79:1.67. After ultrasonic treatment for 20 min, 12 mL of glutaraldehyde was added, and microwave irradiation was carried out with stirring at 50 °C for 5 min. It was successively washed with 0.1 mol / L sodium hydroxide solution, absolute ethanol, and water, and dried at 80 °C to obtain chitosan-modified activated carbon.

[0027] Preparation Example 3 The activated carbon was activated at 530 °C for 1 h. Chitosan was dissolved in 110 mL of 2 wt% acetic acid solution with a chitosan concentration of 11.25 g / L. The activated carbon after activation was added and mixed. The mass ratio of activated carbon to chitosan was 1.72:1.65. After ultrasonic treatment for 18 min, 11 mL of glutaraldehyde was added, and microwave irradiation was carried out with stirring at 50 °C for 4 min. It was successively washed with 0.1 mol / L sodium hydroxide solution, absolute ethanol, and water, and dried at 80 °C to obtain chitosan-modified activated carbon.

[0028] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that in Preparation Example 4, the mass ratio of activated carbon to chitosan is 1.65:1.21.

[0029] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 1 is that in Preparation Example 5, the mass ratio of activated carbon to chitosan is 1.65:2.

[0030] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 1 is that in Preparation Example 6, chitosan is pretreated as follows: Dissolve ascorbic acid in water, add chitosan and dissolve it. The mass ratio of ascorbic acid to chitosan is 1.321:1.462. Mix evenly, let it stand overnight, then filter to obtain a filtrate, and freeze-dry to obtain modified chitosan.

[0031] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 1 is that in Preparation Example 7, chitosan is pretreated as follows: Dissolve ascorbic acid in water, add chitosan and dissolve it. The mass ratio of ascorbic acid to chitosan is 1.305:1.268. Mix evenly, let it stand overnight, then filter to obtain a filtrate, and freeze-dry to obtain modified chitosan.

[0032] Preparation Examples 8 - 23 of Activated Carbon Zeolite Composite Adsorbent Preparation Example 8 The preparation method of the activated carbon zeolite composite adsorbent includes the following steps: Mix zeolite and activated carbon with a mass ratio of 0.8:0.9, add a 2wt% polyvinyl alcohol solution and stir. The addition amount of polyvinyl alcohol is 13wt% of the activated carbon zeolite composite adsorbent. After drying to a water content of 30%, extrude it into a shape, and then dry it at 200°C for 1h to obtain the activated carbon zeolite composite adsorbent. In this preparation example, the activated carbon used is commercially available powdered activated carbon, and the zeolite used is zeolite particles obtained by cleaning, drying, and pulverizing clinoptilolite.

[0033] Preparation Example 9 The preparation method of the activated carbon zeolite composite adsorbent includes the following steps: Mix zeolite and activated carbon with a mass ratio of 1.1:1.0, add a 2wt% polyvinyl alcohol solution and stir. The addition amount of polyvinyl alcohol is 15wt% of the activated carbon zeolite composite adsorbent. After drying to a water content of 50%, extrude it into a shape, and then dry it at 220°C for 1h to obtain the activated carbon zeolite composite adsorbent. In this preparation example, the activated carbon used is commercially available powdered activated carbon, and the zeolite used is zeolite particles obtained by cleaning, drying, and pulverizing clinoptilolite.

[0034] Preparation Example 10 Preparation method of activated carbon zeolite composite adsorbent, comprising the following steps: Mix zeolite and activated carbon with a mass ratio of (0.8 - 1.1):(0.9 - 1.0), add 2wt% polyvinyl alcohol solution and stir. The addition amount of polyvinyl alcohol is 14wt% of the activated carbon zeolite composite adsorbent. After drying to a water content of 40%, extrude into shape, and then dry at 210°C for 1h to obtain the activated carbon zeolite composite adsorbent. In this preparation example, the activated carbon used is commercially available powdered activated carbon, and the zeolite used is zeolite particles prepared by cleaning, drying, and pulverizing clinoptilolite.

[0035] Preparation Example 11 The difference between Preparation Example 11 and Preparation Example 8 is that in Preparation Example 11, the activated carbon used is the chitosan-modified activated carbon prepared in Preparation Example 1.

[0036] Preparation Example 12 The difference between Preparation Example 12 and Preparation Example 8 is that in Preparation Example 12, the activated carbon used is the chitosan-modified activated carbon prepared in Preparation Example 2.

[0037] Preparation Example 13 The difference between Preparation Example 13 and Preparation Example 8 is that in Preparation Example 13, the activated carbon used is the chitosan-modified activated carbon prepared in Preparation Example 3.

[0038] Preparation Example 14 The difference between Preparation Example 14 and Preparation Example 8 is that in Preparation Example 14, the activated carbon used is the chitosan-modified activated carbon prepared in Preparation Example 4.

[0039] Preparation Example 15 The difference between Preparation Example 15 and Preparation Example 8 is that in Preparation Example 15, the activated carbon used is the chitosan-modified activated carbon prepared in Preparation Example 5.

[0040] Preparation Example 16 The difference between Preparation Example 16 and Preparation Example 8 is that in Preparation Example 16, the activated carbon used is the chitosan-modified activated carbon prepared in Preparation Example 6.

[0041] Preparation Example 17 The difference between Preparation Example 17 and Preparation Example 8 is that in Preparation Example 17, the activated carbon used is the chitosan-modified activated carbon prepared in Preparation Example 7.

[0042] Preparation Example 18 The difference between Preparation Example 18 and Preparation Example 8 is that in Preparation Example 18, the mass ratio of zeolite to activated carbon is 0.8:0.5.

[0043] Preparation Example 19 The difference between Preparation Example 19 and Preparation Example 8 is that in Preparation Example 19, the mass ratio of zeolite to activated carbon is 0.8:1.5.

[0044] Preparation Example 20 The difference between Preparation Example 20 and Preparation Example 8 is that in Preparation Example 20, the addition amount of polyvinyl alcohol is 8 wt% of the activated carbon zeolite composite adsorbent.

[0045] Preparation Example 21 The difference between Preparation Example 21 and Preparation Example 8 is that in Preparation Example 21, the addition amount of polyvinyl alcohol is 20 wt% of the activated carbon zeolite composite adsorbent.

[0046] Preparation Example 22 The difference between Preparation Example 22 and Preparation Example 8 is that in Preparation Example 22, the zeolite is treated as follows: The zeolite is placed in a 15 wt% sodium hydroxide solution, activated for 13 h, and then calcined and fixed at 400 °C to obtain activated zeolite.

[0047] Preparation Example 23 The difference between Preparation Example 23 and Preparation Example 8 is that in Preparation Example 23, the zeolite is treated as follows: The zeolite is placed in a 17 wt% sodium hydroxide solution, activated for 12 h, and then calcined and fixed at 420 °C to obtain activated zeolite. Examples

[0048] Example 1 A method for recycling and reusing an electroplating solution for integrated circuits, comprising the following steps: (1) The electroplating solution is passed through a copper ion selective adsorption resin at a flow rate of 14 mL / min to obtain a mixed solution. After the adsorption amount reaches 80%, the copper ion selective adsorption resin is eluted, and the eluent is sulfuric acid to obtain an eluate. The copper ion selective adsorption resin is of type D851; (2) A composite adsorbent is added to the mixed solution to adjust the pH to 4. The composite adsorbent is an activated carbon zeolite composite adsorbent, and the activated carbon zeolite composite adsorbent prepared in Preparation Example 8 is used. After stirring and shaking for 6 h, centrifugation and filtration are carried out to obtain a filtrate; (3) The eluate and the filtrate are mixed to obtain a regenerated electroplating solution.

[0049] Example 2 A method for recycling and reusing an electroplating solution for integrated circuits, comprising the following steps: (1) The electroplating solution is passed through a copper ion selective adsorption resin at a flow rate of 16 mL / min to obtain a mixed solution. After the adsorption amount reaches 80%, the copper ion selective adsorption resin is eluted, and the eluent is sulfuric acid to obtain an eluate. The copper ion selective adsorption resin is of type D711; (2) Add a composite adsorbent to the mixed solution and adjust the pH to 6. The composite adsorbent is an activated carbon zeolite composite adsorbent. Select the activated carbon zeolite composite adsorbent prepared in Preparation Example 9. After stirring and shaking for 7 h, centrifuge and filter to obtain a filtrate; (3) Mix the eluate and the filtrate to obtain a regenerated electroplating solution.

[0050] Example 3 A method for recycling and regenerating an electroplating solution for integrated circuits includes the following steps: (1) Pass the electroplating solution through a copper ion selective adsorption resin at a flow rate of 15 mL / min to obtain a mixed solution. After the adsorption amount reaches 80%, elute the copper ion selective adsorption resin. The eluent is sulfuric acid to obtain an eluate. The copper ion selective adsorption resin is of type D711; (2) Add a composite adsorbent to the mixed solution and adjust the pH to 5. The composite adsorbent is an activated carbon zeolite composite adsorbent. Select the activated carbon zeolite composite adsorbent prepared in Preparation Example 10. After stirring and shaking for 7 h, centrifuge and filter to obtain a filtrate; (3) Mix the eluate and the filtrate to obtain a regenerated electroplating solution.

[0051] Example 4 The difference between Example 4 and Example 1 is that in Example 4, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 11.

[0052] Example 5 The difference between Example 5 and Example 1 is that in Example 5, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 12.

[0053] Example 6 The difference between Example 6 and Example 1 is that in Example 6, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 13.

[0054] Example 7 The difference between Example 7 and Example 1 is that in Example 7, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 14.

[0055] Example 8 The difference between Example 8 and Example 1 is that in Example 8, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 15.

[0056] Example 9 The difference between Example 9 and Example 1 is that in Example 9, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 16.

[0057] Example 10 The difference between Example 10 and Example 1 is that in Example 10, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 17.

[0058] Example 11 The difference between Example 11 and Example 1 is that in Example 11, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 18.

[0059] Example 12 The difference between Example 12 and Example 1 is that in Example 12, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 19.

[0060] Example 13 The difference between Example 13 and Example 1 is that in Example 13, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 20.

[0061] Example 14 The difference between Example 14 and Example 1 is that in Example 14, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 21.

[0062] Example 15 The difference between Example 15 and Example 1 is that in Example 15, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 22.

[0063] Example 16 The difference between Example 16 and Example 1 is that in Example 16, the composite adsorbent is the activated carbon zeolite composite adsorbent prepared in Preparation Example 23.

[0064] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, the copper ion selective adsorption resin was not used, the composite adsorbent was directly added to the electroplating solution, the pH was adjusted to 4, stirred and shaken for 6 h, centrifuged, filtered, and an equal amount of eluent was added to obtain the regenerated electroplating solution.

[0065] Detection Method According to the recycling methods of Examples 1-16 and Comparative Example 1, the electroplating solution for integrated circuits was recycled. Before recycling, the contents of copper ions, iron ions, zinc ions, and organic impurity TOC in the electroplating solution were detected, and the contents of copper ions, iron ions, zinc ions, and organic impurity TOC in the recycled electroplating solution were detected. In each example and comparative example, the dosage of the eluent was the same. The retention rate of copper ions after recycling, as well as the removal rates of iron ions, zinc ions, and organic impurity TOC, were calculated, and the results were recorded in Table 1.

[0066] Table 1 Changes in Ions and Organic Impurities before and after Electroplating Solution Recycling Project Copper ion / % Iron ion / % Zinc ion / % TOC / % Example 1 94.12 85.26 83.18 84.84 Example 2 93.92 86.61 84.64 83.67 Example 3 94.08 86.24 83.26 84.62 Example 4 97.65 94.91 93.81 95.18 Example 5 96.01 93.32 91.61 94.37 Example 6 97.91 94.15 92.59 93.67 Example 7 92.61 91.67 90.63 91.51 Example 8 93.57 89.91 88.45 89.91 Example 9 94.12 98.24 96.18 97.52 Example 10 93.39 97.61 97.64 98.61 Example 11 92.91 81.81 79.91 80.84 Example 12 93.35 82.27 81.31 81.38 Example 13 92.92 82.64 80.25 80.27 Example 14 94.15 85.91 84.64 84.67 Example 15 93.62 89.26 88.16 90.18 Example 16 92.89 90.51 86.81 89.94 Comparative Example 1 65.23 72.64 75.60 81.68 Combined with Examples 1-3, Comparative Example 1, and Table 1, it can be seen that the content of copper ions in the recycled electroplating solution of Examples 1-3 is higher than that of Comparative Example 1, and the removal rates of iron ions, zinc ions, and TOC are higher than those of Comparative Example 1. This shows that the recycling methods of Examples 1-3 have better recycling effects on electroplating than Comparative Example 1. In Comparative Example 1, a copper ion selective adsorption resin was not used to adsorb and elute copper ions, and a composite adsorbent was directly added to the electroplating solution. During the adsorption process of the composite adsorbent, some copper ions were adsorbed, resulting in an increase in the loss of copper ions. At the same time, since some adsorption sites were occupied by copper ions, the adsorption amount and adsorption effect of the composite adsorbent on iron ions, zinc ions, and organic impurities were reduced, leading to an increase in the removal rate. In Examples 1-3, a copper ion selective adsorption resin was used to adsorb and elute copper ions to achieve the separation of copper ions. The main adsorption targets of the composite adsorbent were iron ions, zinc ions, and organic impurities, etc. The interference of copper ions was reduced, and the removal rate was improved. Finally, the eluent containing copper ions was mixed with the filtrate from which impurities had been removed to obtain the recycled electroplating solution.

[0067] Combined with Examples 4-6 and Examples 1-3, it can be seen that the removal rates of iron ions, zinc ions, and TOC in Examples 4-6 have increased. In Examples 4-6, chitosan-modified activated carbon was used. Chitosan contains many hydroxyl groups and amino groups, which can coordinate with iron ions, zinc ions, etc. to achieve the adsorption of metal ions, thereby increasing the removal rates of iron ions, zinc ions, etc. At the same time, chitosan has good viscosity and can adsorb organic impurities, resulting in an increase in the removal rates of iron ions, zinc ions, and TOC in Examples 4-6.

[0068] It can be seen from Examples 7-8 in combination with Examples 4-6 that the removal rates of iron ions, zinc ions and TOC in Examples 7-8 decreased. In the preparation process of chitosan-modified activated carbon in Examples 7-8, the mass ratio of activated carbon to chitosan was adjusted. During the modification process, chitosan could coat the outside of the activated carbon and crosslink with the activated carbon. The addition amount of chitosan decreased, resulting in a decrease in the content of chitosan in the chitosan-modified activated carbon, and the coordination binding effect between chitosan and metals decreased. An increase in the addition amount of chitosan was likely to cause blockage of the pores of the activated carbon, resulting in a decrease in its adsorption performance.

[0069] It can be seen from Examples 9-10 in combination with Examples 4-6 that the removal rates of iron ions, zinc ions and TOC in Examples 9-10 increased. In Examples 9-10, chitosan was pretreated with ascorbic acid before use. The reaction product of chitosan and ascorbic acid could form chelates with metal ions, which was beneficial to improving the binding strength between chitosan and metal ions, reducing the reverse reaction during the adsorption process of the composite adsorbent, and thus improving the adsorption effect.

[0070] It can be seen from Examples 11-12 in combination with Examples 1-3 that the removal rates of iron ions, zinc ions and TOC in Examples 11-12 decreased. In Examples 11-12, the mass ratio of activated carbon to zeolite was changed, indicating that the mass ratio of activated carbon to zeolite had an impact on the adsorption effect of the composite adsorbent. Activated carbon and zeolite had different adsorption selectivities for organic impurities. After the activated carbon and zeolite were compounded in a certain proportion, they could effectively adsorb the impurities in the mixed solution. When the mass ratio changed, the contents of zeolite and activated carbon changed, resulting in a decrease in the adsorption effect.

[0071] It can be seen from Examples 13-14 in combination with Examples 1-3 that the removal rates of iron ions, zinc ions and TOC in Example 13 decreased, and the removal rates of iron ions, zinc ions and TOC in Example 14 were similar to those in Examples 1-3. In Examples 13-14, the addition amount of polyvinyl alcohol was changed. Polyvinyl alcohol had good viscosity and could bond zeolite and activated carbon. When the addition amount of the polyvinyl alcohol solution decreased, the mixed bonding strength of the two decreased, making the connection between the activated carbon and zeolite loose, and the formability of the composite adsorbent was poor. When the addition amount of the polyvinyl alcohol solution increased, the removal rate did not increase significantly.

[0072] It can be seen from Examples 15-16 in combination with Examples 1-3 that the removal rates of iron ions, zinc ions and TOC in Examples 15-16 increased. In Examples 15-16, the zeolite was activated. After the zeolite was treated with sodium hydroxide solution, the alkali solution reacted with the impurities in the zeolite, dredging the pores of the zeolite, increasing the number of mesopores and micropores in the zeolite, and thus increasing the specific surface area and adsorption performance of the activated zeolite.

[0073] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A method for recycling an integrated circuit electroplating solution, characterized in that: The following steps are involved: (1) The electroplating solution is passed through a copper ion selective adsorption resin at a flow rate of 14-16 mL / min to obtain a mixed solution. After the adsorption amount reaches 80%, the copper ion selective adsorption resin is eluted using sulfuric acid as an eluent to obtain an eluent; (2) adding a composite adsorbent to the mixed solution, adjusting the pH to 4-6, wherein the composite adsorbent is an activated carbon zeolite composite adsorbent, stirring and shaking for 6-7 hours, centrifuging, filtering, and obtaining a filtrate; (3) The eluent and the filtrate are mixed to obtain a regenerated electroplating solution.

2. The method for recycling an integrated circuit electroplating solution according to claim 1, characterized in that: The preparation method of the activated carbon zeolite composite adsorbent comprises the following steps: mixing zeolite and activated carbon, adding polyvinyl alcohol solution and stirring, drying to a water content of 30-50%, extruding and molding, and drying at 200-220° C. for 1 hour to obtain the activated carbon zeolite composite adsorbent.

3. The method for recycling an integrated circuit electroplating solution according to claim 2, characterized in that: The mass ratio of the zeolite to the activated carbon is (0.8-1.1):(0.9-1.0).

4. The method for recycling an integrated circuit electroplating solution according to claim 2, characterized in that: The added amount of the polyvinyl alcohol is 13-15wt% of the activated carbon zeolite composite adsorbent.

5. The method for recycling an integrated circuit electroplating solution according to claim 2, characterized in that: The activated carbon is pretreated as follows: the activated carbon is activated at 500-550° C. for 1-1.2 hours, chitosan is dissolved in a 2wt% acetic acid solution, the activated activated carbon is added and mixed, ultrasonicated for 15-20 minutes, glutaraldehyde is added, microwave irradiation is performed at 45-50° C. for 4-5 minutes while stirring, and the activated carbon is washed with 0.1 mol / L sodium hydroxide solution, anhydrous ethanol and water in sequence, and dried at 80° C. to obtain chitosan-modified activated carbon.

6. The method for recycling an integrated circuit electroplating solution according to claim 5, characterized in that: The mass ratio of the activated carbon to chitosan is (1.65-1.79):(1.62-1.67).

7. The method for recycling an integrated circuit electroplating solution according to claim 5, characterized in that: The chitosan is pretreated as follows: ascorbic acid is dissolved in water, chitosan is added and dissolved, mixed evenly, left to stand overnight, filtered to obtain a filtrate, and freeze-dried to obtain modified chitosan.

8. The method for recycling an integrated circuit electroplating solution according to claim 2, characterized in that: The zeolite is treated as follows: the zeolite is placed in a 15-17 wt% sodium hydroxide solution, activated for 12-13 hours, and then calcined at 400-420° C. to obtain an activated zeolite.