Method for recovering high-activity copper oxide from alkaline etching waste liquid based on ammonia distillation method

Abstract

The invention provides a method for recovering high-activity copper oxide from alkaline etching waste liquid based on an ammonia distillation method, and belongs to the field of resourceful treatment of copper-containing waste liquid. The method comprises the following steps: filtering the alkaline etching waste liquid to remove suspended matters; carrying out adsorption coupling on dimethyl glyoxime and diatomite to remove impurities; carrying out gradient ammonia distillation treatment combining normal-pressure ammonia distillation and negative-pressure ammonia distillation on the impurity-removed etching waste liquid to obtain a basic cupric carbonate crude product; dissolving the basic cupric carbonate crude product in a urea solution to obtain a copper tetraammine carbonate solution; carrying out secondary negative pressure ammonia distillation treatment to obtain a basic cupric carbonate fine product with a spherical honeycomb structure; and carrying out graded calcination and water vapor activation co-treatment to obtain high-activity copper oxide. According to the method, the dimethyl glyoxime-diatomite coupling impurity removal, gradient ammonia distillation, urea dissolution, secondary ammonia distillation, graded calcination and water vapor activation treatment processes are combined, the quality and performance of a copper oxide product are improved, the high-activity copper oxide powder for PCB electroplating is obtained, and efficient cyclic utilization of copper resources is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of resource treatment of copper-containing waste liquid, and particularly relates to a method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia evaporation method. Background Art

[0002] In the process of printed circuit board (PCB) processing, etching is an essential operation step. The purpose of etching is to remove the unprotected non-conductive part of copper on the patterned PCB to form circuits. Etching includes inner-layer etching and outer-layer etching. Acid etching is used for the inner layer, and alkaline etching is used for the outer layer. The alkaline etching solution is ammonium chloride + copper chloride + ammonia water + etching salt. A large amount of alkaline etching waste liquid containing copper ammonia complex (such as [Cu(NH3)4] 2+ ) is generated during the PCB etching process. Due to the high copper content in this waste liquid, if it is directly discharged without treatment, it will cause serious harm to the environment.

[0003] Traditional recovery methods (such as neutralization precipitation and electrolysis) have problems such as low purity, high energy consumption, or ammonia pollution. Although the ammonia evaporation method can release copper ions, direct precipitation is difficult to meet the requirements of electronic-grade copper oxide (purity ≥ 99.5%, specific surface area ≥ 30 m 2 / g) for PCB electroplating. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia evaporation method, aiming to solve at least one technical problem in the background art.

[0005] The present invention is realized as follows: A method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia evaporation method, which includes the following steps: Filter the alkaline etching waste liquid to remove suspended solids; Dimethylglyoxime - diatomite adsorption coupling for impurity removal; Perform gradient ammonia evaporation treatment by combining atmospheric ammonia evaporation and vacuum ammonia evaporation on the impurity-removed etching waste liquid to obtain crude basic copper carbonate; Dissolve the crude basic copper carbonate in a urea solution to obtain a tetraamminecopper carbonate solution; Perform secondary vacuum ammonia evaporation treatment to obtain high-quality basic copper carbonate with a spherical honeycomb structure; Perform hierarchical calcination and steam activation on the high-quality basic copper carbonate in a coordinated manner to obtain highly active copper oxide.

[0006] Further, the step of dimethylglyoxime - diatomite adsorption coupling for impurity removal specifically includes: Adjust the pH of the filtered etching waste liquid to weakly alkaline; Add 0.1wt%-0.3wt% dimethylglyoxime to the weakly alkaline etching waste liquid, stir at room temperature for 20min - 40min to form a precipitate of Ni impurities; After solid-liquid separation, the solution passes through a diatomite dynamic adsorption tower at a flow rate of 2BV / h - 3BV / h to adsorb colloids and organic impurities.

[0007] Further, the pH of the weakly alkaline etching waste liquid is 8.0 - 8.2.

[0008] Further, the step of subjecting the impurity-removed etching waste liquid to gradient ammonia distillation by combining atmospheric ammonia distillation and vacuum ammonia distillation specifically includes: Perform atmospheric ammonia distillation at 80°C - 95°C until the ammonia concentration < 20%; Perform vacuum ammonia distillation at 60°C - 70°C and a vacuum degree of -0.08MPa - -0.05MPa to remove residual ammonia and obtain crude basic copper carbonate; Wash with ethanol and water to remove adsorbed impurity ions on the surface.

[0009] Further, according to the molar ratio, urea:basic copper carbonate = 4 - 6:1; The temperature for dissolving the crude basic copper carbonate in the urea solution is 70°C - 90°C; The concentration of the urea solution is 20wt% - 30wt%.

[0010] Further, the temperature of the secondary vacuum ammonia distillation is 85°C - 95°C, and the vacuum degree is -0.03MPa - -0.01MPa.

[0011] Further, the step of subjecting the high-quality basic copper carbonate to hierarchical calcination and steam activation synergistically specifically includes: putting the dried high-quality basic copper carbonate into a microwave calcination furnace and performing gradient calcination activation treatment in an air atmosphere.

[0012] Further, the gradient calcination activation treatment specifically includes: Raise the temperature to 200°C - 300°C at the first heating rate and hold for 0.5h - 1.5h; Raise the temperature to 400°C - 500°C at the second heating rate, introduce 2wt% - 4wt% steam into the microwave calcination furnace, and hold for 0.5h - 1.5h to obtain highly active copper oxide.

[0013] Further, the first heating rate is 4°C / min - 6°C / min; the second heating rate is 8°C / min - 12°C / min.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention combines the processes of dimethylglyoxime - diatomite coupled impurity removal, gradient ammonia evaporation, urea dissolution + secondary ammonia evaporation, and fractional calcination + steam activation treatment to improve the quality and performance of copper oxide products, significantly reduce the time required for acid dissolution, obtain highly active copper oxide powder for PCB electroplating, and achieve the efficient recycling of copper resources.

[0015] 2. The method of the present invention is not only environmentally friendly but also easy to implement and suitable for industrial production applications.

[0016] 3. The copper oxide prepared by the present invention has the advantages of uniform particle size, high purity, few impurities, large specific surface area, fast acid dissolution rate, etc., and can be used as highly active copper oxide with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the process flow chart of the method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia evaporation method of the present invention; Figure 2 is the particle size distribution diagram of the copper oxide prepared in Example 1 of the present invention; Figure 3 is the SEM diagram of the copper oxide prepared in Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the following examples are used to further elaborate on the present invention in detail. It should be understood that the specific implementation cases described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] As Figure 1 shown, the method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia evaporation method includes steps S1 - step S6.

[0020] S1. Filter the alkaline etching waste liquid to remove suspended solids; The main components of the PCB alkaline etching waste liquid include copper ammonia complex, free ammonia, chloride, additives (such as oxidants, organic corrosion inhibitors, organic stabilizers, etc.) and metal impurities (mainly nickel Ni 2+ ), and due to the complex composition, it is very easy to form scum during homogenization in the adjustment tank, which is not conducive to subsequent treatment. Therefore, the PCB alkaline etching waste liquid is first filtered and pretreated to remove suspended solids.

[0021] S2. Dimethylglyoxime - diatomite adsorption coupled impurity removal; (1) Adjust the pH of the filtered etching waste liquid to weakly alkaline, specifically pH = 8.0 - 8.2; the weakly alkaline condition is beneficial for subsequent removal of metal impurities by dimethylglyoxime; (2) Add 0.1wt%-0.3wt% dimethylglyoxime (DMG) to the weakly alkaline etching waste liquid, stir at room temperature for 20 min to 40 min to form a precipitate of Ni impurities; the presence of copper ammonia complex and free ammonia in the PCB alkaline etching waste liquid inhibits the reaction between copper ions and dimethylglyoxime. Under the condition of adding a small amount of dimethylglyoxime, it reacts preferentially with Ni 2+ to form a chelate precipitate Ni(DMG)2; (3) After solid-liquid separation, the solution passes through a diatomite dynamic adsorption tower at a flow rate of 2BV / h to 3BV / h for further adsorption of colloids and organic impurities; the diatomite dynamic adsorption tower can effectively remove colloidal particles and some organic substances in the PCB alkaline etching waste liquid.

[0022] S3, gradient ammonia distillation treatment combining atmospheric ammonia distillation and vacuum ammonia distillation to obtain crude basic copper carbonate; (1) Perform atmospheric ammonia distillation at 80°C to 95°C until the ammonia concentration < 20%; (2) Perform vacuum ammonia distillation at 60°C to 70°C and a vacuum degree of -0.08 MPa to -0.05 MPa to remove residual ammonia; (3) Wash the solid product obtained by vacuum ammonia distillation with ethanol and water to remove the impurity ions adsorbed on the surface to obtain crude basic copper carbonate.

[0023] S4, prepare a solution of tetraamminecopper carbonate; According to the molar ratio, urea: basic copper carbonate = 4 to 6:1, preferably 5:1; the temperature for dissolving the crude basic copper carbonate in the urea solution is 70°C to 90°C, preferably 80°C; the concentration of the urea solution is 20wt% to 30wt%. In the present invention, urea is used to replace liquid ammonia or carbonated ammonia aqueous solution to dissolve the crude basic copper carbonate, controllably release ammonia, avoid the high risk of directly using liquid ammonia, the operation is safer, and there is no use of acid and alkali, which is more environmentally friendly.

[0024] S5, secondary vacuum ammonia distillation: Under the conditions of 85°C to 95°C and a vacuum degree of -0.03 MPa to -0.01 MPa, perform secondary vacuum ammonia distillation treatment on the tetraamminecopper carbonate solution prepared in S4 to obtain high-quality basic copper carbonate with a spherical honeycomb structure; heat the solution under vacuum conditions to volatilize free ammonia, destroy the copper ammonia complex equilibrium, and promote the re-precipitation of copper in the form of high-purity basic copper carbonate. At the same time, volatile impurities (such as residual ammonia and organic amines) are removed.

[0025] S6, hierarchical calcination + steam activation synergistic treatment of high-quality basic copper carbonate to obtain high-activity copper oxide; Put the dried high-quality basic copper carbonate into a microwave calcination furnace and perform gradient calcination activation treatment in an air atmosphere.

[0026] The gradient calcination activation treatment specifically includes: Heat up at a heating rate of 4°C / min to 6°C / min to 200°C to 300°C, keep warm for 0.5 h to 1.5 h, preferably 1 h; Heat up at a heating rate of 8°C / min to 12°C / min to 400°C to 500°C, introduce water vapor into the microwave calcination furnace, and its dosage is 2 wt% to 4 wt% of the high-quality basic copper carbonate, keep warm for 0.5 h to 1.5 h, preferably 1 h, to obtain highly active copper oxide.

[0027] The copper recovery rate of the present invention is ≥98%, the purity of copper oxide is ≥99.5%, and the Cl content is less than 10 ppm; The particle size distribution of the copper oxide prepared by the present invention is controllable, and the specific surface area is ≥30 m 2 / g, the complete dissolution time of 10 g of CuO in 200 mL of 10% dilute sulfuric acid is ≤10 s, meeting the performance requirements of highly active copper oxide for PCB electroplating.

[0028] Example 1 A method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia evaporation method, which includes the following steps: S1, filter the alkaline etching waste liquid to remove suspended solids.

[0029] S2, adjust the pH of the etching waste liquid after S1 treatment to 8.1; add 0.2 wt% dimethylglyoxime, stir at room temperature for 30 min, and after solid-liquid separation, the solution passes through a diatomite dynamic adsorption tower at a flow rate of 2.5 BV / h to further adsorb colloids and organic impurities.

[0030] S3, first perform atmospheric ammonia evaporation at 90°C until the ammonia concentration <20%; then perform negative pressure ammonia evaporation at 65°C and -0.06 MPa vacuum to remove residual ammonia; finally, wash the solid product obtained by negative pressure ammonia evaporation with ethanol and water to remove surface-adsorbed impurity ions to obtain crude basic copper carbonate.

[0031] S4, prepare a urea solution at a concentration of 25 wt%, add a certain amount of crude basic copper carbonate to the urea solution according to urea:basic copper carbonate = 5:1 (molar ratio), and heat up to 80°C for dissolution to obtain a tetraamminecopper carbonate solution.

[0032] S5, perform secondary negative pressure ammonia evaporation treatment at a temperature of 90°C and a vacuum of -0.02 MPa to obtain high-quality basic copper carbonate with a spherical honeycomb structure.

[0033] S6. Dry the high-quality basic copper carbonate obtained in S5, then put it into a microwave calcination furnace. Under an air atmosphere, first heat it to 250 °C at a heating rate of 5 °C / min and hold for 1 h; then heat it to 450 °C at a heating rate of 10 °C / min, introduce 3 wt% water vapor into the microwave calcination furnace, and hold for 1 h to obtain highly active copper oxide, whose particle size distribution is as Figure 2 shown, and its SEM is as Figure 3 shown.

[0034] Example 2 A method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia distillation method, which includes the following steps: S1. Filter the alkaline etching waste liquid to remove suspended solids.

[0035] S2. Adjust the pH of the etching waste liquid treated in S1 to 8.0; add 0.3 wt% dimethylglyoxime, stir at room temperature for 40 min, and after solid-liquid separation, the solution passes through a diatomite dynamic adsorption tower at a flow rate of 3 BV / h for further adsorption of colloids and organic impurities.

[0036] S3. First, perform atmospheric ammonia distillation at 80 °C until the ammonia concentration < 20%; then perform negative-pressure ammonia distillation at 60 °C and a vacuum degree of -0.08 MPa to remove residual ammonia; finally, wash the solid product obtained by negative-pressure ammonia distillation with ethanol and water to remove the impurity ions adsorbed on the surface to obtain crude basic copper carbonate.

[0037] S4. Prepare a urea solution at a concentration of 30 wt%, add a certain amount of crude basic copper carbonate to the urea solution according to the ratio of urea:basic copper carbonate = 4:1 (molar ratio), and heat it to 70 °C for dissolution to obtain a tetraamminecopper carbonate solution.

[0038] S5. Perform secondary negative-pressure ammonia distillation treatment at a temperature of 85 °C and a vacuum degree of -0.02 MPa to obtain high-quality basic copper carbonate with a spherical honeycomb structure.

[0039] S6. Dry the high-quality basic copper carbonate obtained in S5, then put it into a microwave calcination furnace. Under an air atmosphere, first heat it to 200 °C at a heating rate of 4 °C / min and hold for 1 h; then heat it to 400 °C at a heating rate of 8 °C / min, introduce 2 wt% water vapor into the microwave calcination furnace, and hold for 1 h to obtain highly active copper oxide.

[0040] Example 3 A method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia distillation method, which includes the following steps: S1. Filter the alkaline etching waste liquid to remove suspended solids.

[0041] S2. Adjust the pH of the etched waste liquid after S1 treatment to 8.2; add 0.1 wt% dimethylglyoxime, stir at room temperature for 40 min, and after solid-liquid separation, the solution passes through a diatomite dynamic adsorption column at a flow rate of 3 BV / h for further adsorption of colloids and organic impurities.

[0042] S3. First, perform atmospheric ammonia evaporation at 80 °C until the ammonia concentration < 20%; then perform negative pressure ammonia evaporation at 70 °C and a vacuum degree of -0.05 MPa to remove residual ammonia; finally, wash the solid product obtained by negative pressure ammonia evaporation with ethanol and water to remove the impurity ions adsorbed on the surface to obtain crude basic copper carbonate.

[0043] S4. Prepare a urea solution at a concentration of 20 wt%, and add a certain amount of crude basic copper carbonate to this urea solution according to the molar ratio of urea:basic copper carbonate = 6:1, and heat up to 90 °C for dissolution to obtain a tetraamminecopper carbonate solution.

[0044] S5. Perform secondary negative pressure ammonia evaporation treatment at a temperature of 95 °C and a vacuum degree of -0.02 MPa to obtain high-quality basic copper carbonate with a spherical honeycomb structure.

[0045] S6. Dry the high-quality basic copper carbonate prepared in S5, and then put it into a microwave calcination furnace. First, heat it up to 300 °C at a heating rate of 6 °C / min in an air atmosphere and keep it warm for 1 h; then heat it up to 500 °C at a heating rate of 12 °C / min, and introduce 4 wt% water vapor into the microwave calcination furnace and keep it warm for 1 h to obtain highly active copper oxide.

[0046] Comparative Example 1 Based on Example 1, in this comparative example, the gradient ammonia evaporation treatment in step S3 is adjusted to a single atmospheric ammonia evaporation, and other steps and conditions are the same as those in Example 1.

[0047] Step S3 in this comparative example is specifically as follows: perform atmospheric ammonia evaporation at 90 °C to remove ammonia; wash the solid product obtained by negative pressure ammonia evaporation with ethanol and water to remove the impurity ions adsorbed on the surface to obtain crude basic copper carbonate.

[0048] Comparative Example 2 Based on Example 1, in this comparative example, the gradient ammonia evaporation treatment in step S3 is adjusted to a single negative pressure ammonia evaporation, and other steps and conditions are the same as those in Example 1.

[0049] Step S3 in this comparative example is specifically as follows: perform negative pressure ammonia evaporation at 65 °C and a vacuum degree of -0.06 MPa to remove ammonia; wash the solid product obtained by negative pressure ammonia evaporation with ethanol and water to remove the impurity ions adsorbed on the surface to obtain crude basic copper carbonate.

[0050] Comparative Example 3 On the basis of Example 1, this comparative example deletes step S2, and other steps and conditions are the same as those in Example 1.

[0051] Comparative Example 4 On the basis of Example 1, this comparative example replaces urea in step S4 with liquid ammonia solution, and other steps and conditions are the same as those in Example 1.

[0052] Comparative Example 5 On the basis of Example 1, this comparative example replaces the gradient calcination in step S6 with single-stage calcination, and other steps and conditions are the same as those in Example 1.

[0053] Step S6 in this comparative example is specifically as follows: drying the basic copper carbonate product obtained in S5, then putting it into a microwave calcination furnace, heating it to 450 °C at a heating rate of 10 °C / min in an air atmosphere, introducing 3 wt% water vapor into the microwave calcination furnace, and keeping it warm for 2 h to obtain copper oxide.

[0054] Comparative Example 6 On the basis of Example 1, this comparative example does not introduce 3 wt% water vapor during the gradient calcination in step S6, and other steps and conditions are the same as those in Example 1.

[0055] The products prepared in Examples 1 to 3 and Comparative Examples 1 to 6 were detected. The CuO purity, specific surface area, and impurity Cl content were respectively detected, and their acid dissolution rates were measured. The detection method of the acid dissolution rate: the time required for completely dissolving 10 g of the product to be detected in 200 mL of 10% dilute sulfuric acid. The longer the time, the slower the acid dissolution rate. The results are shown in Table 1. Among them, the speed of the acid dissolution rate directly reflects the activity of copper oxide. A fast acid dissolution rate indicates high activity, and a slow acid dissolution rate indicates low activity.

[0056] Table 1

[0057] From the data in Table 1, it can be seen that the copper oxide products prepared in the examples of the present invention have a purity of ≥99.5%, a Cl content of less than 10 ppm, a specific surface area of ≥30 m 2 / g, and a relatively fast acid dissolution rate, meeting the performance requirements of high-activity electronic copper oxide for electronic industries such as PCB electroplating.

[0058] Comparing Comparative Example 1 and Comparative Example 2 with Example 1 respectively, it can be seen that in S3, single normal pressure or negative pressure ammonia evaporation is used for ammonia evaporation. The purity of the obtained copper oxide product decreases, the Cl content increases, the time required for acid dissolution increases to more than 15 seconds, and the specific surface area decreases significantly. It can be seen that the copper oxide purity and activity of the products prepared in Comparative Example 1 and Comparative Example 2 are lower than those in Example 1.

[0059] Comparing Comparative Example 3 with Example 1, it can be seen that in the case of deleting the dimethylglyoxime - diatomite adsorption coupling impurity removal in step S2, the time required for acid dissolution of the obtained product and the change in specific surface area are not obvious, but the purity of copper oxide drops significantly and the Cl content increases significantly. It can be seen that the purity of copper oxide in the product obtained in Comparative Example 3 is significantly lower than that in Example 1.

[0060] Comparing Comparative Example 4 with Example 1, it can be seen that the urea in S4 is replaced with an ammonia solution. The purity of the obtained copper oxide product drops slightly, the Cl content increases, the time required for acid dissolution increases, and the specific surface area decreases significantly. It can be seen that the activity of the copper oxide product obtained in Comparative Example 4 is lower than that in Example 1.

[0061] Comparing Comparative Example 5 with Example 1, it can be seen that the gradient calcination in step S6 is replaced with primary calcination. The purity change of the obtained copper oxide product is not obvious, the Cl content increases slightly, but the specific surface area decreases and the time required for acid dissolution increases. It can be seen that the activity of the copper oxide product obtained in Comparative Example 5 is significantly lower than that in Example 1.

[0062] Comparing Comparative Example 6 with Example 1, it can be seen that no steam is introduced for activation treatment during calcination. The purity of the obtained copper oxide product hardly changes, the Cl content increases slightly, but the time required for acid dissolution increases and the specific surface area decreases significantly. It can be seen that the activity of the copper oxide product obtained in Comparative Example 6 is lower than that in Example 1.

[0063] In the electronics industry such as PCB electroplating, electronic copper oxide is required to have properties such as high activity, high purity, and low chlorine. It is difficult for the copper oxides obtained in Comparative Examples 1 to 6 to meet the above performance requirements.

[0064] The above - described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia distillation method, characterized in that, The method includes the following steps: Filter the alkaline etching waste liquid to remove suspended solids; Perform impurity removal by the adsorption coupling of dimethylglyoxime - diatomite; Perform gradient ammonia evaporation treatment on the etching waste liquid after impurity removal by combining atmospheric ammonia evaporation and vacuum ammonia evaporation to obtain crude basic copper carbonate; Dissolve the crude basic copper carbonate in a urea solution to obtain a tetraamminecopper(II) carbonate solution; Perform secondary vacuum ammonia evaporation treatment to obtain high-quality basic copper carbonate with a spherical honeycomb structure; Perform synergistic treatment on the high-quality basic copper carbonate by hierarchical calcination and steam activation to obtain highly active copper oxide.

2. The method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia distillation method according to claim 1, characterized in that, The step of performing impurity removal by the adsorption coupling of dimethylglyoxime - diatomite specifically includes: Adjust the pH of the filtered etching waste liquid to weakly alkaline; Add 0.1wt% - 0.3wt% dimethylglyoxime to the weakly alkaline etching waste liquid, stir at room temperature for 20 min - 40 min to form a precipitate of Ni impurities; After solid-liquid separation, the solution passes through a diatomite dynamic adsorption tower at a flow rate of 2 BV / h - 3 BV / h to adsorb colloids and organic impurities.

3. The method for recovering highly active copper oxide from alkaline etching waste liquor based on the ammonia distillation method according to claim 2, characterized in that, The pH of the weakly alkaline etching waste liquid is 8.0 - 8.

2.

4. The method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia distillation method according to claim 1, characterized in that, The step of performing gradient ammonia evaporation treatment on the etching waste liquid after impurity removal by combining atmospheric ammonia evaporation and vacuum ammonia evaporation specifically includes: Perform atmospheric ammonia evaporation at 80°C - 95°C until the ammonia concentration < 20%; Perform vacuum ammonia evaporation at 60°C - 70°C and a vacuum degree of -0.08 MPa - -0.05 MPa to remove residual ammonia and obtain crude basic copper carbonate; Wash with ethanol and water to remove adsorbed impurity ions on the surface.

5. The method for recovering highly active copper oxide from alkaline etching waste liquor based on the ammonia distillation method according to claim 1, characterized in that, According to the molar ratio, urea:basic copper carbonate = 4 - 6:1; The temperature for dissolving the crude basic copper carbonate in the urea solution is 70°C - 90°C; The concentration of the urea solution is 20wt% - 30wt%.

6. The method for recovering highly active copper oxide from alkaline etching waste liquor based on the ammonia distillation method according to claim 1, characterized in that, The temperature of the secondary vacuum ammonia evaporation is 85°C - 95°C, and the vacuum degree is -0.03 MPa - -0.01 MPa.

7. The method for recovering highly active copper oxide from alkaline etching waste liquor based on the ammonia distillation method according to claim 1, characterized in that, The step of performing synergistic treatment on the high-quality basic copper carbonate by hierarchical calcination and steam activation specifically includes: Put the dried high-quality basic copper carbonate into a microwave calcination furnace and perform gradient calcination activation treatment in an air atmosphere.

8. The method for recovering highly active copper oxide from alkaline etching waste liquid based on the ammonia distillation method according to claim 7, characterized in that, The gradient calcination activation treatment specifically includes: Heat up to 200°C - 300°C at the first heating rate and keep it warm for 0.5 h - 1.5 h; Heat up to 400°C - 500°C at the second heating rate, introduce 2wt% - 4wt% steam into the microwave calcination furnace, and keep it warm for 0.5 h - 1.5 h to obtain highly active copper oxide.

9. The method for recovering highly active copper oxide from alkaline etching waste liquor based on the ammonia distillation method according to claim 8, characterized in that, The first heating rate is 4°C / min - 6°C / min; the second heating rate is 8°C / min - 12°C / min.

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