A process for producing basic copper carbonate from acidic copper-containing etching waste liquid

Abstract

The invention discloses a process for producing basic copper carbonate from acidic copper-containing etching waste liquid, belongs to the technical field of waste liquid recycling, and comprises the following steps: diluting the acidic copper-containing etching waste liquid with distilled water, adding anhydrous ethanol to obtain a mixed liquid, adding the mixed liquid dropwise to a mixed precipitant, obtaining a suspension, heating and stirring after the dropwise addition is completed, filtering while hot, washing the filter cake, and drying to obtain basic copper carbonate. The present invention adds anhydrous ethanol to the diluted acidic copper-containing etching waste liquid, when the hydrolysis reaction occurs, the generated basic copper carbonate particles are soaked in anhydrous ethanol, the surface tension of the basic copper carbonate particles is small, and the basic copper carbonate particles are not easy to agglomerate and grow. Then, the present invention adds a modified surfactant, which can be adsorbed on the surface of the basic copper carbonate particles to form a steric hindrance, plays a good dispersing effect, and effectively solves the problem of easy agglomeration between the basic copper carbonate particles.

Description

Technical Field

[0001] The invention belongs to the technical field of waste liquid recycling, and in particular relates to a process for producing basic copper carbonate from acidic copper-containing etching waste liquid. Background Art

[0002] Common PCB production processes include cutting and drilling, copper plating, pattern transfer plating, film stripping, etching, green oil printing, pad plating, molding inspection and other processes. Among them, the processing quality of the etching process directly affects the circuit performance of the PCB board and is an important link in PCB production. Copper-containing etching liquid is widely used in the manufacturing process of PCB because of its advantages such as fast speed, high efficiency and controllable etching effect. Therefore, with the expansion of the PCB industry, a large amount of etching waste liquid is also generated.

[0003] Etching waste liquid is mainly divided into two types: alkaline and acidic. The copper content is generally 100-160g / L. The main components of acidic copper chloride etching waste liquid are hydrochloric acid, copper chloride, etc. Using acidic copper-containing etching waste liquid to produce basic copper carbonate is a common way of utilizing waste liquid. Basic copper carbonate can be used as a precursor to obtain nano copper oxide through calcination. Nano copper oxide of different particle sizes has different optical, electrical, magnetic and other properties. In the prior art, the basic copper carbonate produced by acidic copper-containing etching waste liquid is mostly block agglomerates, which is not conducive to the subsequent development of basic copper carbonate. Therefore, by improving the process of producing basic copper carbonate from acidic copper-containing etching waste liquid and reducing the particle size range and particle size of basic copper carbonate, the subsequent processing cost of basic copper carbonate can be significantly reduced, which has positive significance. Summary of the invention

[0004] The object of the present invention is to provide a process for producing basic copper carbonate from acidic copper-containing etching waste liquid, so as to solve the problem that basic copper carbonate particles are prone to agglomeration.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A process for producing basic copper carbonate from acidic copper-containing etching waste liquid comprises the following steps:

[0007] The acidic copper-containing etching waste liquid is diluted with distilled water, and anhydrous ethanol is added to the diluted acidic copper-containing etching waste liquid with stirring to obtain a mixed liquid, and the mixed liquid is added dropwise to the mixed precipitant to obtain a suspension, and the dropping time is controlled to be 1 hour. When the dropping is completed, the pH of the suspension is controlled to be 7.0-8.0. After the dropping is completed, the temperature is raised to 70-80°C, stirred for 30 minutes, filtered while hot, and the filter cake is washed with distilled water until the conductivity of the washing liquid is less than 10S / cm, and dried at 105°C for 2.5 hours to obtain basic copper carbonate.

[0008] Furthermore, the volume ratio of the distilled water to the acidic copper-containing etching waste liquid is 3-4:1.

[0009] Furthermore, the volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and mixed precipitant is 8-10:5:50.

[0010] Furthermore, the mixed precipitant is prepared by mixing sodium carbonate and a modified surfactant in a ratio of 2g-3g:10mL.

[0011] Furthermore, the modified surfactant is prepared by the following steps:

[0012] A1. Add N,N-dialkylethylenediamine to anhydrous ethanol, raise the temperature to 45°C, stir at constant temperature until the solid is completely dissolved, slowly drop a saturated aqueous solution of sodium bromoacetate into the solution, and during the reaction, adjust the pH of the system to 8.8-9.2 using an anhydrous methanol solution of sodium hydroxide, reflux for 18 hours, and obtain a solution after the reaction is completed;

[0013] A2. Add 35% concentrated hydrochloric acid to the above solution to adjust the pH to 1.5-2.0, stir and let stand for 10 minutes, a white solid precipitate appears, filter, wash the filter cake three times with anhydrous ethanol and deionized water, and dry to obtain a modified surfactant.

[0014] Furthermore, in step A1, the dosage ratio of N,N-dialkylethylenediamine and saturated aqueous solution of sodium bromoacetate is 0.125 mol:0.25 mol.

[0015] Further, the N,N-dialkylethylenediamine is prepared by the following steps:

[0016] B1. Add ethylenediamine to n-propanol with stirring, raise the temperature to 95-98° C., add 1-bromodecane dropwise to the n-propanol under the reflux condition, adjust the pH of the system to 7.5-8.0 with anhydrous methanol solution of sodium hydroxide during the reaction, stir for 24 hours, filter while hot after the reaction is completed, and evaporate the solvent from the filtrate by rotary evaporation to obtain a solid product;

[0017] B2. Add the above solid product to a 30% sodium hydroxide aqueous solution, stir for 4 hours, heat to boiling in a boiling water bath, and then cool to room temperature to precipitate a solid, filter, and take a filter cake. Wash the filter cake three times with anhydrous ethanol and distilled water to obtain an intermediate product. The intermediate product is recrystallized using anhydrous acetone to obtain N,N-dialkylethylenediamine.

[0018] Furthermore, in step B1, the usage ratio of n-propanol, ethylenediamine and 1-bromododecane is 100 mL: 0.05 moL: 0.11 moL.

[0019] Beneficial effects of the present invention:

[0020] In the process of producing basic copper carbonate by using acidic copper-containing etching waste liquid, firstly, anhydrous ethanol is added to the diluted acidic copper-containing etching waste liquid by stirring, and copper chloride in the etching waste liquid is dissolved in the anhydrous ethanol in the form of molecules, and when a hydrolysis reaction occurs, the generated basic copper carbonate particles are immersed in the anhydrous ethanol, the surface tension of the basic copper carbonate particles is small, and the basic copper carbonate particles are not easy to agglomerate and grow.

[0021] Then, the present invention adds a modified surfactant, which is adsorbed on the surface of the basic copper carbonate particles to form a steric hindrance, plays a good dispersing role, and hinders the agglomeration of the basic copper carbonate particles. At the same time, the modified surfactant in the present invention uses an ethylenediamine group as a connecting group, a -CH2COOH hydrophilic group connected to a nitrogen atom, and a long carbon chain as a hydrophobic group to form an amino acid surfactant. The amino acid structure in the amino acid surfactant has a pH-sensitive group (carboxyl group, etc.). During the hydrolysis process of producing basic copper carbonate from acidic copper-containing etching waste liquid, the pH changes continuously. The modified surfactant prepared by the present invention can better adapt to the changes in the pH environment of the system and effectively prevent the occurrence of agglomeration. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] Preparation of N,N-dialkylethylenediamine:

[0025] B1. Add ethylenediamine to n-propanol with stirring, raise the temperature to 95°C, and add 1-bromodecane dropwise under the reflux condition of n-propanol. During the reaction, adjust the pH of the system to 7.5 with anhydrous methanol solution of sodium hydroxide, stir for 24 hours, and after the reaction is completed, filter while hot, and evaporate the solvent from the filtrate by rotary evaporation to obtain a light yellow solid product; wherein the dosage ratio of n-propanol, ethylenediamine and 1-bromodecane is 100mL:0.05moL:0.11moL.

[0026] B2. Add the solid product to a 30% aqueous sodium hydroxide solution, stir for 4 hours, heat to boiling in a boiling water bath, and then cool to room temperature to precipitate a light yellow solid. Filter and take the filter cake. Wash the filter cake three times with anhydrous ethanol and distilled water to obtain a white solid product. The white solid product is recrystallized with anhydrous acetone to obtain white needle-shaped N,N-dialkylethylenediamine.

[0027] Example 2

[0028] Preparation of N,N-dialkylethylenediamine:

[0029] B1. Add ethylenediamine to n-propanol with stirring, raise the temperature to 96°C, and add 1-bromodecane dropwise under the reflux condition of n-propanol. During the reaction, adjust the pH value of the system to 7.8 with anhydrous methanol solution of sodium hydroxide. Stir for 24 hours. After the reaction is completed, filter while hot, and evaporate the solvent from the filtrate by rotary evaporation to obtain a light yellow solid product; wherein the dosage ratio of n-propanol, ethylenediamine and 1-bromodecane is 100mL:0.05moL:0.11moL.

[0030] B2. Add the solid product to a 30% aqueous sodium hydroxide solution, stir for 4 hours, heat to boiling in a boiling water bath, and then cool to room temperature to precipitate a light yellow solid. Filter and take the filter cake. Wash the filter cake three times with anhydrous ethanol and distilled water to obtain a white solid product. The white solid product is recrystallized with anhydrous acetone to obtain white needle-shaped N,N-dialkylethylenediamine.

[0031] Example 3

[0032] Preparation of N,N-dialkylethylenediamine:

[0033] B1. Add ethylenediamine to n-propanol with stirring, raise the temperature to 98°C, and add 1-bromodecane dropwise under the reflux condition of n-propanol. During the reaction, adjust the pH of the system to 8.0 with anhydrous methanol solution of sodium hydroxide, stir for 24 hours, and after the reaction is completed, filter while hot, and evaporate the solvent from the filtrate by rotary evaporation to obtain a light yellow solid product; wherein the dosage ratio of n-propanol, ethylenediamine and 1-bromodecane is 100mL:0.05moL:0.11moL.

[0034] B2. Add the solid product to a 30% aqueous sodium hydroxide solution, stir for 4 hours, heat to boiling in a boiling water bath, and then cool to room temperature to precipitate a light yellow solid. Filter and take the filter cake. Wash the filter cake three times with anhydrous ethanol and distilled water to obtain a white solid product. The white solid product is recrystallized with anhydrous acetone to obtain white needle-shaped N,N-dialkylethylenediamine.

[0035] Example 4

[0036] Preparation of modified surfactant:

[0037] A1. Add N,N-dialkylethylenediamine prepared in Example 1 to anhydrous ethanol, heat to 45°C, stir at constant temperature until the solid is completely dissolved, slowly dropwise add saturated aqueous solution of sodium bromoacetate, and during the reaction, adjust the pH of the system to 8.8 using an anhydrous methanol solution of sodium hydroxide, reflux for 18 hours, and after the reaction, obtain a light yellow solution; wherein, the amount ratio of N,N-dialkylethylenediamine to the saturated aqueous solution of sodium bromoacetate is 0.125 mol: 0.25 mol.

[0038] A2. Add 35% concentrated hydrochloric acid to the light yellow solution to adjust the pH to 1.5, stir and let stand for 10 minutes, a white solid precipitate appears, filter, wash the filter cake three times with anhydrous ethanol and deionized water, and dry to obtain a modified surfactant.

[0039] Example 5

[0040] Preparation of modified surfactant:

[0041] A1. Add N,N-dialkylethylenediamine prepared in Example 2 to anhydrous ethanol, heat to 45°C, stir at constant temperature until the solid is completely dissolved, slowly dropwise add saturated aqueous solution of sodium bromoacetate, and during the reaction, adjust the pH of the system to 9.0 using an anhydrous methanol solution of sodium hydroxide, reflux for 18 hours, and after the reaction, obtain a light yellow solution; wherein, the amount ratio of N,N-dialkylethylenediamine to the saturated aqueous solution of sodium bromoacetate is 0.125 mol:0.25 mol.

[0042] A2. Add 35% concentrated hydrochloric acid to the light yellow solution to adjust the pH to 1.8, stir and let stand for 10 minutes, a white solid precipitate appears, filter, wash the filter cake three times with anhydrous ethanol and deionized water, and dry to obtain a modified surfactant.

[0043] Example 6

[0044] Preparation of modified surfactant:

[0045] A1. Add N,N-dialkylethylenediamine prepared in Example 3 to anhydrous ethanol, heat to 45°C, stir at constant temperature until the solid is completely dissolved, slowly dropwise add saturated aqueous solution of sodium bromoacetate, and during the reaction, adjust the pH of the system to 9.2 using anhydrous methanol solution of sodium hydroxide, reflux for 18 hours, and after the reaction, obtain a light yellow solution; wherein, the amount ratio of N,N-dialkylethylenediamine to saturated aqueous solution of sodium bromoacetate is 0.125 mol:0.25 mol.

[0046] A2. Add 35% concentrated hydrochloric acid to the light yellow solution to adjust the pH to 2.0, stir and let stand for 10 minutes, a white solid precipitate appears, filter, wash the filter cake three times with anhydrous ethanol and deionized water, and dry to obtain a modified surfactant.

[0047] Example 7

[0048] A process for producing basic copper carbonate from acidic copper-containing etching waste liquid:

[0049] The main chemical composition of acidic copper-containing etching waste liquid: Cu 2+ 106.0g / L, Cl - 211.7 g / L;

[0050] The acidic copper-containing etching waste liquid is diluted with distilled water, and the volume ratio of distilled water to the acidic copper-containing etching waste liquid is 3:1. Anhydrous ethanol is added to the diluted acidic copper-containing etching waste liquid with stirring to obtain a mixed liquid, and the mixed liquid is added dropwise to a mixed precipitant, wherein the mixed precipitant is prepared by mixing sodium carbonate and the modified surfactant prepared in Example 4 according to 2g:10mL, wherein the volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and the mixed precipitant is 8:5:50. After the dropwise addition is completed, a suspension is obtained, and the dropwise addition time is controlled to be 1h. When the dropwise addition is completed, the pH of the suspension is controlled to be 7.0. After the dropwise addition is completed, the temperature is raised to 70°C, stirred for 30min, filtered while hot, and the filter cake is washed with distilled water until the conductivity of the washing liquid is 10S / cm, and dried at 105°C for 2.5h to obtain basic copper carbonate. According to particle size detection, the particle size range of the prepared basic copper carbonate particles is 24-67nm, and the prepared basic copper carbonate particles have uniform particle size.

[0051] Example 8

[0052] A process for producing basic copper carbonate from acidic copper-containing etching waste liquid:

[0053] The main chemical composition of acidic copper-containing etching waste liquid: Cu 2+ 106.0g / L, Cl - 211.7 g / L;

[0054] The acidic copper-containing etching waste liquid is diluted with distilled water, the volume ratio of distilled water to the acidic copper-containing etching waste liquid is 3.5:1, anhydrous ethanol is added to the diluted acidic copper-containing etching waste liquid with stirring to obtain a mixed liquid, and the mixed liquid is added dropwise to a mixed precipitant, wherein the mixed precipitant is prepared by mixing sodium carbonate and the modified surfactant prepared in Example 5 at a ratio of 2.5 g:10 mL, wherein the volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and the mixed precipitant is 9:1. : 5:50, after the addition is completed, a suspension is obtained, the dropping time is controlled to be 1h, and the pH value of the suspension is controlled to be 7.6 when the dropping is completed. After the addition is completed, the temperature is raised to 75°C, stirred for 30min, filtered while hot, and the filter cake is washed with distilled water until the conductivity of the washing liquid is 8.2S / cm. It is dried at 105°C for 2.5h to obtain basic copper carbonate. The particle size detection shows that the particle size range of the prepared basic copper carbonate particles is 25-54nm, and the prepared basic copper carbonate particles have uniform particle size.

[0055] Example 9

[0056] A process for producing basic copper carbonate from acidic copper-containing etching waste liquid:

[0057] The main chemical composition of acidic copper-containing etching waste liquid: Cu 2+ 106.0g / L, Cl - 211.7 g / L;

[0058] The acidic copper-containing etching waste liquid is diluted with distilled water, and the volume ratio of distilled water to the acidic copper-containing etching waste liquid is 4:1. Anhydrous ethanol is added to the diluted acidic copper-containing etching waste liquid with stirring to obtain a mixed liquid, and the mixed liquid is added dropwise to a mixed precipitant, wherein the mixed precipitant is prepared by mixing sodium carbonate and the modified surfactant prepared in Example 6 according to 3g:10mL, wherein the volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and the mixed precipitant is 10:5:50. After the dropwise addition is completed, a suspension is obtained, and the dropwise addition time is controlled to be 1h. When the dropwise addition is completed, the pH of the suspension is controlled to be 8.0. After the dropwise addition is completed, the temperature is raised to 80°C, stirred for 30min, filtered while hot, and the filter cake is washed with distilled water until the conductivity of the washing liquid is 9.4S / cm. It is dried at 105°C for 2.5h to obtain basic copper carbonate. According to particle size detection, the particle size range of the prepared basic copper carbonate particles is 28-70nm, and the prepared basic copper carbonate particles have uniform particle size.

[0059] Comparative Example 1

[0060] A process for producing basic copper carbonate from acidic copper-containing etching waste liquid: (for comparison with Example 7)

[0061] The acidic copper-containing etching waste liquid is diluted with distilled water, and the volume ratio of distilled water to the acidic copper-containing etching waste liquid is 3:1. Anhydrous ethanol is added to the diluted acidic copper-containing etching waste liquid with stirring to obtain a mixed liquid, and the mixed liquid is added dropwise to a mixed precipitant, wherein the mixed precipitant is prepared by mixing sodium carbonate and sodium dodecyl sulfate according to 2g:10mL, wherein the volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and the mixed precipitant is 8:5:50. After the dropwise addition is completed, a suspension is obtained, and the dropwise addition time is controlled to be 1h. When the dropwise addition is completed, the pH of the suspension is controlled to be 7.0. After the dropwise addition is completed, the temperature is raised to 70°C, stirred for 30min, filtered while hot, and the filter cake is washed with distilled water until the conductivity of the washing liquid is 10S / cm, and dried at 105°C for 2.5h to obtain basic copper carbonate. According to the particle size detection, the particle size range of the prepared basic copper carbonate particles is 58-132nm.

[0062] Comparative Example 2

[0063] A process for producing basic copper carbonate from acidic copper-containing etching waste liquid: (for comparison with Example 8)

[0064] The acidic copper-containing etching waste liquid is diluted with distilled water, and the volume ratio of distilled water to the acidic copper-containing etching waste liquid is 3.5:1. Anhydrous ethanol is added to the diluted acidic copper-containing etching waste liquid with stirring to obtain a mixed liquid, and the mixed liquid is added dropwise to a mixed precipitant, wherein the mixed precipitant is prepared by mixing sodium carbonate and distilled water according to 2.5g:10mL, wherein the volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and the mixed precipitant is 9:5:50. After the dropwise addition is completed, a suspension is obtained, and the dropwise addition time is controlled to be 1h. When the dropwise addition is completed, the pH of the suspension is controlled to be 7.6. After the dropwise addition is completed, the temperature is raised to 75°C, stirred for 30min, filtered while hot, and the filter cake is washed with distilled water until the conductivity of the washing liquid is 8.2S / cm. It is dried at 105°C for 2.5h to obtain basic copper carbonate. According to the particle size detection, the particle size range of the prepared basic copper carbonate particles is 75-280nm.

[0065] Comparative Example 3

[0066] A process for producing basic copper carbonate from acidic copper-containing etching waste liquid: (for comparison with Example 9)

[0067] The acidic copper-containing etching waste liquid is diluted with distilled water, and the volume ratio of distilled water to the acidic copper-containing etching waste liquid is 4:1 to obtain a mixed liquid, and the mixed liquid is added dropwise to a mixed precipitant, wherein the mixed precipitant is prepared by mixing sodium carbonate and the modified surfactant prepared in Example 6 according to 3g:10mL, wherein the volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and the mixed precipitant is 10:5:50, and after the dropwise addition is completed, a suspension is obtained, and the dropwise addition time is controlled to be 1h. When the dropwise addition is completed, the pH of the suspension is controlled to be 8.0. After the dropwise addition is completed, the temperature is raised to 80°C, stirred for 30min, filtered while hot, and the filter cake is washed with distilled water until the conductivity of the washing liquid is 9.4S / cm, and dried at 105°C for 2.5h to obtain basic copper carbonate. According to particle size detection, the particle size range of the prepared basic copper carbonate particles is 65-175nm.

[0068] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0069] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for producing basic copper carbonate from acidic copper-containing etching waste liquid, characterized in that: The following steps are involved: Dilute the acidic copper-containing etching waste liquid with distilled water, add anhydrous ethanol to the diluted acidic copper-containing etching waste liquid with stirring to obtain a mixed liquid, add the mixed liquid dropwise to the mixed precipitant to obtain a suspension, control the dropping time to be 1 hour, control the pH of the suspension to be 7.0-8.0 when the dropping is completed, raise the temperature to 70-80° C. after the dropping is completed, stir for 30 minutes, filter while hot, wash the filter cake with distilled water until the conductivity of the washing liquid is less than 10S / cm, and dry at 105° C. for 2.5 hours to obtain basic copper carbonate; The mixed precipitant is prepared by mixing sodium carbonate and a modified surfactant in a ratio of 2g-3g:10mL; The modified surfactant is prepared by the following steps: A1. Add N,N-dialkylethylenediamine to anhydrous ethanol, raise the temperature to 45°C, and stir at a constant temperature until the solid is completely dissolved. Slowly drop a saturated aqueous solution of sodium bromoacetate thereto. During the reaction, adjust the pH of the system to 8.8-9.2 using an anhydrous methanol solution of sodium hydroxide. Reflux for 18 hours. After the reaction is completed, a solution is obtained. A2. Add 35% concentrated hydrochloric acid to the above solution to adjust the pH to 1.5-2.0, stir and let stand for 10 minutes, a white solid precipitate will appear, filter, wash the filter cake three times with anhydrous ethanol and deionized water, and dry to obtain a modified surfactant.

2. A process for producing basic copper carbonate from an acidic copper-containing etching waste liquid according to claim 1, characterized in that: The volume ratio of the distilled water to the acidic copper-containing etching waste liquid is 3-4:

1.

3. A process for producing basic copper carbonate from an acidic copper-containing etching waste liquid according to claim 1, characterized in that: The volume ratio of the diluted acidic copper-containing etching waste liquid, anhydrous ethanol and mixed precipitant is 8-10:5:

50.

4. The process for producing basic copper carbonate from an acidic copper-containing etching waste liquid according to claim 1, characterized in that: The usage ratio of N,N-dialkylethylenediamine and saturated aqueous solution of sodium bromoacetate in step A1 is 0.125 mol:0.25 mol.

5. The process for producing basic copper carbonate from acidic copper-containing etching waste liquid according to claim 1, characterized in that: The N,N-dialkylethylenediamine is prepared by the following steps: B1. Add ethylenediamine to n-propanol with stirring, raise the temperature to 95-98° C., add 1-bromodecane dropwise thereto under the reflux condition of n-propanol, adjust the pH of the system to 7.5-8.0 with anhydrous methanol solution of sodium hydroxide during the reaction, stir for 24 hours, filter while hot after the reaction is completed, and evaporate the solvent from the filtrate by rotary evaporation to obtain a solid product; B2. Add the above solid product to a 30% sodium hydroxide aqueous solution, stir for 4 hours, heat to boiling in a boiling water bath, and then cool to room temperature to precipitate a solid, filter, and take a filter cake. Wash the filter cake three times with anhydrous ethanol and distilled water to obtain an intermediate product. The intermediate product is recrystallized using anhydrous acetone to obtain N,N-dialkylethylenediamine.

6. The process for producing basic copper carbonate from acidic copper-containing etching waste liquid according to claim 5, characterized in that: The usage ratio of n-propanol, ethylenediamine and 1-bromododecane in step B1 is 100 mL: 0.05 mol: 0.11 mol.