Method for producing cuprous oxide from PCB waste resin powder and copper-containing etching waste liquid

Abstract

The invention belongs to the technical field of waste liquid treatment, and particularly relates to a method for producing cuprous oxide from PCB waste resin powder and copper-containing etching waste liquid, and the method comprises the following steps: S1, mixing and reacting the PCB waste resin powder and the copper-containing etching waste liquid to obtain a cuprous solution 1; s2, phosphoric acid and ammonia water are added into the cuprous solution 1, stirring and filter pressing are conducted, and a cuprous solution 2 and impurity-removed filter residues are obtained; and S3, adding ammonia water into the cuprous solution 2, centrifuging and washing to obtain a cuprous oxide and ammonium chloride solution. According to the method provided by the invention, high-purity cuprous oxide can be obtained, the purity is greater than 99%, the copper recovery rate is greater than 99%, copper is not detected from the reacted PCB waste resin powder, the economic benefit is improved, and the cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of waste liquid treatment technology, specifically relating to a method for producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid. Background Technology

[0002] Printed circuit boards (PCBs), as a fundamental electronic component, are widely used in various electronic and related products. In recent years, my country's PCB industry has developed rapidly, resulting in a continuous increase in waste generated from PCB production. PCBs consist of metallic and non-metallic components. Non-metallic components mainly include resin, glass fiber, and additives. Currently, companies mainly focus on the recycling of metallic components in PCB waste, while research on the recycling of non-metallic components is relatively limited.

[0003] Chinese Patent Publication No. CN 112808742 B discloses a method and system for treating printed circuit board waste. The method includes copper dissolution reaction, impurity removal from browning waste liquid, and organic matter recycling. The system includes a copper dissolution reaction unit, a browning waste liquid impurity removal unit, an organic matter recycling unit, and a copper sulfate synthesis unit. This invention provides a method and system for treating printed circuit board waste that can simultaneously treat three types of waste: acidic etching waste liquid, browning waste liquid, and waste scraps. It enables the recovery and reuse of valuable components (copper metal and organic matter) from the waste. The resulting product has high purity and can be sold externally or used to prepare browning solutions for reuse. However, the resin residue after copper dissolution is not recycled in this technical solution.

[0004] Cuprous oxide is an important inorganic chemical product with wide applications in coatings, glass ceramics, chemical catalysis, and other fields. In the existing technology, Xu Gaojin et al. published "Recovery of Cuprous Oxide and Sodium Chloride from Acidic Copper Chloride Etching Waste Liquid" in the journal Electroplating and Finishing. The technical solution is to neutralize the acidic copper chloride etching waste liquid with sodium hydroxide and use hydrazine hydrate as a reducing agent to prepare cuprous oxide. However, this technical solution cannot recycle non-metallic waste generated by PCB.

[0005] Therefore, it is of great significance to provide a method for producing cuprous oxide from waste resin powder of PCB circuit boards and copper-containing etching waste liquid so as to achieve the simultaneous recovery of cuprous oxide from waste resin powder of PCB circuit boards and copper-containing etching waste liquid. Summary of the Invention

[0006] The present invention aims to solve one or more technical problems existing in the prior art, and at least provides a beneficial solution. Specifically, the present invention provides a method for producing cuprous oxide from PCB waste resin powder and copper-containing etching waste liquid. This method can obtain high-purity cuprous oxide with a purity greater than 99%, a copper recovery rate greater than 99%, and no copper is detected in the PCB waste resin powder after the reaction, thereby improving economic efficiency and reducing costs.

[0007] To achieve the above-mentioned objective, this invention provides a method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid, comprising the following steps:

[0008] S1. Mix waste resin powder from PCB circuit boards and copper-containing etching waste liquid, react, and obtain copper(II) solution 1.

[0009] S2. Add phosphoric acid and ammonia to cuprous solution 1, stir, filter under pressure to obtain cuprous solution 2 and impurity-removed filter residue;

[0010] S3. Add ammonia to cuprous solution 2, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution;

[0011] The amount of ammonia added in step S2 is to adjust the pH of cuprous solution 1 to 1.5-1.8;

[0012] The amount of ammonia added in step S3 is to adjust the pH of cuprous solution 2 to 5.5-7.

[0013] Optionally, the waste resin powder from the PCB circuit board mentioned in step S1 contains 0.5-1 wt% copper.

[0014] Optionally, the copper concentration in the copper-containing etching waste liquid in step S1 is 8-11 wt%, and the acidity is 2-4 mol / L.

[0015] Optionally, the weight ratio of the PCB circuit board waste resin powder and the copper-containing etching waste liquid in step S1 is 80-120:1.

[0016] Optionally, the reaction temperature in step S1 is 25-30°C, and the reaction time is 10-12 hours.

[0017] Optionally, the amount of phosphoric acid added in step S2 is 1.3-1.7 times the total content of metal impurities in the copper-containing etching waste liquid.

[0018] Optionally, the metallic impurities in the copper-containing etching waste liquid include iron, nickel, zinc, calcium, and magnesium.

[0019] Optionally, activated carbon may be added in step S2 before adding phosphoric acid and ammonia.

[0020] Optionally, the amount of activated carbon added is 0.2-0.3% of the weight of the copper-containing etching waste liquid.

[0021] Optionally, the stirring temperature in step S2 is 25-30°C, and the stirring time is 20-40 min.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The method provided by this invention is the first to jointly recycle and utilize waste resin powder from PCB circuit boards and copper-containing etching waste liquid to prepare cuprous oxide. This method not only recycles and regenerates high-purity cuprous oxide (purity greater than 99%) for application in fields such as paint, cosmetics, medical treatment, and electroplating, but also reduces the generation of hazardous waste. The conditions of this invention are mild (room temperature and pressure), which not only avoids the problem of difficult-to-treat wastewater generated by the reaction, but also retains usable copper ions (copper recovery rate greater than 99%). At the same time, it improves the copper recovery rate of circuit boards (copper was not detected in the waste resin powder from PCB circuit boards after the reaction), improves economic efficiency, and greatly reduces costs. Attached Figure Description

[0024] Figure 1 This is a flowchart of the method for producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid in Embodiment 1 of the present invention.

[0025] Figure 2 Here is a photograph of the cuprous oxide prepared in Example 1 of this invention;

[0026] Figure 3 The image shows the XRD pattern of cuprous oxide prepared in Example 1 of this invention. Detailed Implementation

[0027] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0028] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.

[0029] Reference Figure 1 A method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid includes the following steps:

[0030] S1. Mix waste resin powder from PCB circuit boards and copper-containing etching waste liquid, react, and obtain copper(II) solution 1.

[0031] S2. Add phosphoric acid and ammonia to cuprous solution 1, stir, filter under pressure to obtain cuprous solution 2 and impurity-removed filter residue;

[0032] S3. Add ammonia to cuprous solution 2, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution;

[0033] The amount of ammonia added in step S2 is to adjust the pH of cuprous solution 1 to 1.5-1.8;

[0034] The amount of ammonia added in step S3 is to adjust the pH of cuprous solution 2 to 5.5-7.

[0035] The main component of PCB circuit board substrate is glass fiber reinforced plastic, and its reinforcing plastic component is mainly thermosetting resin. PCB circuit board waste resin powder refers to the waste resin powder after metals in waste copper clad laminates, circuit boards and circuit boards are recycled through crushing and sorting.

[0036] The waste resin powder of PCB circuit boards mentioned in step S1 of this invention is waste resin powder obtained after crushing and copper extraction on a shaking table from waste circuit boards.

[0037] In some preferred embodiments, the PCB waste resin powder in step S1 contains 0.5-1 wt% copper.

[0038] Specifically, the waste resin powder of the PCB circuit board mentioned in step S1 contains 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, and 1wt% copper, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] In some preferred embodiments, the copper concentration in the copper-containing etching waste liquid in step S1 is 8-11 wt%, and the acidity is 2-4 mol / L.

[0040] Specifically, the copper concentration in the copper-containing etching waste liquid in step S1 is 8wt%, 9wt%, 10wt%, or 11wt%, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. The acidity is 2mol / L, 3mol / L, or 4mol / L, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0041] If the copper concentration and acidity in the copper-containing etching waste liquid exceed the above range, sodium chlorate or hydrogen peroxide, ferrous oxide, cuprous ions, and water can be added to adjust the concentration, and ammonia or liquid alkali can be added to adjust the acidity.

[0042] In some preferred embodiments, the weight ratio of the PCB waste resin powder and the copper-containing etching waste liquid in step S1 is 80-120:1.

[0043] Specifically, the weight ratio of PCB circuit board waste resin powder and copper-containing etching waste liquid in step S1 is 80:1, 90:1, 100:1, 110:1, 120:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0044] In some preferred embodiments, the reaction temperature in step S1 is 25-30°C, and the reaction time is 10-12 hours.

[0045] Specifically, the reaction temperature in step S1 is 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. The reaction time is 10h, 10.5h, 11h, 11.5h, or 12h, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0046] In some preferred embodiments, the amount of phosphoric acid added in step S2 is 1.3-1.7 times the total content of metal impurities in the copper-containing etching waste liquid.

[0047] Specifically, the amount of phosphoric acid added in step S2 is 1.3 times, 1.4 times, 1.5 times, 1.6 times, and 1.7 times the total content of metal impurities in the copper-containing etching waste liquid.

[0048] The copper-containing etching waste liquid contains metallic impurities including iron, nickel, zinc, calcium, and magnesium.

[0049] Specifically, the amount of ammonia added in step S2 is to adjust the pH of the cuprous solution 1 to 1.5, 1.6, 1.7, or 1.8, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0050] In some preferred embodiments, activated carbon may be added in step S2 before adding phosphoric acid and ammonia.

[0051] In some preferred embodiments, the amount of activated carbon added is 0.2-0.3% of the weight of the copper-containing etching waste liquid.

[0052] In some preferred embodiments, the stirring temperature in step S2 is 25-30°C, and the stirring time is 20-40 min.

[0053] Specifically, the stirring temperature in step S2 is 25℃, 26℃, 27℃, 28℃, 29℃, or 30℃, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. The stirring time is 20min, 30min, or 40min, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0054] Specifically, the amount of ammonia added in step S3 is to adjust the pH of the cuprous solution 2 to 5.5, 6, 6.5, or 7, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0055] The ammonium chloride solution obtained in step S3 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0056] The mechanism of the technical solution of this invention is as follows:

[0057] In step S1, the waste resin powder from the PCB circuit board and the copper-containing etching waste liquid react to generate Cu. + : ;

[0058] In step S2, phosphoric acid and ammonia solution react with metallic impurities in cuprous solution 1 under specific pH conditions to form a precipitate, which can be removed by pressure filtration. , Represents metallic impurities;

[0059] In step S3, ammonia is added to hydrolyze cuprous solution 2 to generate cuprous oxide slurry, which is then obtained by centrifugation and washing. ; .

[0060] This invention is the first to jointly recycle and utilize waste resin powder from PCB circuit boards and copper-containing etching waste liquid to prepare cuprous oxide. This not only enables the recycling and regeneration of high-purity cuprous oxide for applications in paint, cosmetics, medical, and electroplating fields, but also reduces the generation of hazardous waste. The mild conditions of this invention (room temperature and pressure) not only avoid the problem of difficult-to-treat wastewater generated by the reaction, but also retain usable copper ions. At the same time, it improves the copper recovery rate of circuit boards, increases economic benefits, and greatly reduces costs.

[0061] During the experiment, the inventors discovered that the pH of the cuprous solution 1 in step S2 needs to be controlled at 1.5-1.8, and the pH of the cuprous solution 2 in step S3 needs to be controlled at 5.5-7; otherwise, the purity of cuprous oxide and the copper recovery rate will be reduced.

[0062] Example 1

[0063] The copper-containing etching waste liquid used in this embodiment is a circuit board etching waste liquid from a circuit board factory, with the following composition: w(Cu): 10.87%; Fe: 28.5 mg / L; Ni: 5.3 mg / L; Zn: 15.9 mg / L; Ca: 8.6 mg / L; Mg: 8.8 mg / L; acidity: 2.33 mol / L; PCB circuit board waste resin powder contains 1 wt% copper.

[0064] A method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid:

[0065] S1. Mix PCB waste resin powder and copper-containing etching waste liquid (the weight ratio of PCB waste resin powder and copper-containing etching waste liquid is 100:1), and react at 25°C for 12 hours to obtain copper(II) solution 1.

[0066] S2. Add activated carbon (0.25% of the weight of copper-containing etching waste liquid) and phosphoric acid (1.5 times the total content of iron, nickel, zinc, calcium and magnesium impurities) to copper solution 1. Adjust the pH to 1.5 with ammonia water. Stir for 30 minutes at 25°C and filter under pressure to obtain copper solution 2 and impurity-removed filter residue.

[0067] S3. Add ammonia to cuprous solution 2 to adjust the pH to 5.5, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution.

[0068] The ammonium chloride solution obtained in step S3 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0069] The cuprous oxide obtained in this example has a purity of 99.6%, a chloride ion content of 85 ppm, no detected sulfate, no detected metallic impurities, and a copper recovery rate of 99.9%.

[0070] Meanwhile, the waste resin powder from the reacted PCB circuit board was tested, and no copper was detected.

[0071] Example 2

[0072] The copper-containing etching waste liquid used in this embodiment is an iron-based copper-containing waste liquid with the following composition: w(Fe): 1.54%; w(Cu): 9.74%; Ni: 22.2 mg / L; Zn: 5.2 mg / L; Ca: 9.1 mg / L; Mg: 18.8 mg / L; acidity: 3.61 mol / L; and PCB circuit board waste resin powder containing 0.5 wt% copper.

[0073] A method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid:

[0074] S1. Mix PCB waste resin powder and copper-containing etching waste liquid (the weight ratio of PCB waste resin powder and copper-containing etching waste liquid is 100:1), and react at 25°C for 12 hours to obtain copper(II) solution 1.

[0075] S2. Add activated carbon (0.25% of the weight of copper-containing etching waste liquid) and phosphoric acid (1.5 times the total content of iron, nickel, zinc, calcium and magnesium impurities) to copper solution 1. Adjust the pH to 1.5 with ammonia water. Stir for 30 minutes at 25°C and filter under pressure to obtain copper solution 2 and impurity-removed filter residue.

[0076] S3. Add ammonia to cuprous solution 2 to adjust the pH to 7, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution.

[0077] The ammonium chloride solution obtained in step S3 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0078] The cuprous oxide obtained in this example has a purity of 99.8%, a chloride ion content of 92 ppm, no detected sulfate, no detected metallic impurities, and a copper recovery rate of 99.9%.

[0079] Meanwhile, the waste resin powder from the reacted PCB circuit board was tested, and no copper was detected.

[0080] Comparative Example 1

[0081] The copper-containing etching waste liquid used in this comparative example was PCB etching waste liquid from a PCB factory, with the following composition: w(Cu): 10.87%; Fe: 28.5 mg / L; Ni: 5.3 mg / L; Zn: 15.9 mg / L; Ca: 8.6 mg / L; Mg: 8.8 mg / L; acidity: 2.33 mol / L; PCB waste resin powder contains 1 wt% copper.

[0082] A method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid:

[0083] S1. Mix PCB waste resin powder and copper-containing etching waste liquid (the weight ratio of PCB waste resin powder and copper-containing etching waste liquid is 100:1), and react at 25°C for 12 hours to obtain copper(II) solution 1.

[0084] S2. Add activated carbon (0.25% of the weight of copper-containing etching waste liquid) and phosphoric acid (1.5 times the total content of iron, nickel, zinc, calcium and magnesium impurities) to cuprous solution 1. Adjust the pH to 1.3 with ammonia water, stir for 30 min at 25℃, filter under pressure to obtain cuprous solution 2 and impurity-removed filter residue.

[0085] S3. Add ammonia to cuprous solution 2 to adjust the pH to 5.5, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution.

[0086] The ammonium chloride solution obtained in step S3 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0087] The cuprous oxide obtained in this comparative example had a purity of 96.2%, a chloride ion content of 100 ppm, and no detected sulfate. The concentrations were: Fe: 17.2 mg / L; Ni: 3.6 mg / L; Zn: 12.8 mg / L; Ca: 3.8 mg / L; Mg: 5.9 mg / L, and the copper recovery rate was 99.1%.

[0088] Meanwhile, the waste resin powder from the reacted PCB circuit board was tested, and no copper was detected.

[0089] As can be seen from the comparison between Example 1 and Comparative Example 1, when the pH of the cuprous oxide solution 1 is adjusted to be lower than 1.5 by ammonia in step S2, the purity of cuprous oxide decreases significantly.

[0090] Comparative Example 2

[0091] The copper-containing etching waste liquid used in this comparative example was PCB etching waste liquid from a PCB factory, with the following composition: w(Cu): 10.87%; Fe: 28.5 mg / L; Ni: 5.3 mg / L; Zn: 15.9 mg / L; Ca: 8.6 mg / L; Mg: 8.8 mg / L; acidity: 2.33 mol / L; PCB waste resin powder contains 1 wt% copper.

[0092] A method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid:

[0093] S1. Mix PCB waste resin powder and copper-containing etching waste liquid (the weight ratio of PCB waste resin powder and copper-containing etching waste liquid is 100:1), and react at 25°C for 12 hours to obtain copper(II) solution 1.

[0094] S2. Add activated carbon (0.25% of the weight of copper-containing etching waste liquid) and phosphoric acid (1.5 times the total content of iron, nickel, zinc, calcium and magnesium impurities) to cuprous solution 1. Adjust the pH to 2 with ammonia water, stir for 30 min at 25℃, and filter under pressure to obtain cuprous solution 2 and impurity-removed filter residue.

[0095] S3. Add ammonia to cuprous solution 2 to adjust the pH to 5.5, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution.

[0096] The ammonium chloride solution obtained in step S3 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0097] The comparative sample yielded cuprous oxide with a purity of 98.1%, a chloride ion content of 85 ppm, no detected sulfate, Fe: 3.3 mg / L; Ni: not detected; Zn: 0.9 mg / L; Ca: 0.08 mg / L; Mg: 0.15 mg / L, and a copper recovery rate of 94.5%.

[0098] Meanwhile, the waste resin powder from the reacted PCB circuit board was tested, and no copper was detected.

[0099] As can be seen from the comparison between Example 1 and Comparative Example 2, when the pH of the cuprous solution 1 is adjusted to be higher than 1.8 with ammonia in step S2, the purity of cuprous oxide decreases slightly and the copper recovery rate decreases significantly.

[0100] Comparative Example 3

[0101] The copper-containing etching waste liquid used in this comparative example was PCB etching waste liquid from a PCB factory, with the following composition: w(Cu): 10.87%; Fe: 28.5 mg / L; Ni: 5.3 mg / L; Zn: 15.9 mg / L; Ca: 8.6 mg / L; Mg: 8.8 mg / L; acidity: 2.33 mol / L; PCB waste resin powder contains 1 wt% copper.

[0102] A method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid:

[0103] S1. Mix PCB waste resin powder and copper-containing etching waste liquid (the weight ratio of PCB waste resin powder and copper-containing etching waste liquid is 100:1), and react at 25°C for 12 hours to obtain copper(II) solution 1.

[0104] S2. Add activated carbon (0.25% of the weight of copper-containing etching waste liquid) and phosphoric acid (1.5 times the total content of iron, nickel, zinc, calcium and magnesium impurities) to copper solution 1. Adjust the pH to 1.5 with ammonia water. Stir for 30 minutes at 25°C and filter under pressure to obtain copper solution 2 and impurity-removed filter residue.

[0105] S3. Add ammonia to cuprous solution 2 to adjust the pH to 5.3, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution.

[0106] The ammonium chloride solution obtained in step S3 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0107] The cuprous oxide obtained in this comparative example had a purity of 99.6%, a chloride ion content of 155 ppm, no detected sulfate, no detected metallic impurities, and a copper recovery rate of 88.1%.

[0108] Meanwhile, the waste resin powder from the reacted PCB circuit board was tested, and no copper was detected.

[0109] As can be seen from the comparison between Example 1 and Comparative Example 3, when the pH of the cuprous solution 2 is adjusted to be lower than 5.5 with ammonia in step S3, the copper recovery rate decreases significantly.

[0110] Comparative Example 4

[0111] The copper-containing etching waste liquid used in this comparative example was PCB etching waste liquid from a PCB factory, with the following composition: w(Cu): 10.87%; Fe: 28.5 mg / L; Ni: 5.3 mg / L; Zn: 15.9 mg / L; Ca: 8.6 mg / L; Mg: 8.8 mg / L; acidity: 2.33 mol / L; PCB waste resin powder contains 1 wt% copper.

[0112] A method for producing cuprous oxide from waste resin powder from PCB circuit boards and copper-containing etching waste liquid:

[0113] S1. Mix PCB waste resin powder and copper-containing etching waste liquid (the weight ratio of PCB waste resin powder and copper-containing etching waste liquid is 100:1), and react at 25°C for 12 hours to obtain copper(II) solution 1.

[0114] S2. Add activated carbon (0.25% of the weight of copper-containing etching waste liquid) and phosphoric acid (1.5 times the total content of iron, nickel, zinc, calcium and magnesium impurities) to copper solution 1. Adjust the pH to 1.5 with ammonia water. Stir for 30 minutes at 25°C and filter under pressure to obtain copper solution 2 and impurity-removed filter residue.

[0115] S3. Add ammonia to cuprous solution 2 to adjust the pH to 7.2, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution.

[0116] The ammonium chloride solution obtained in step S3 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0117] The cuprous oxide obtained in this comparative example had a purity of 99.6%, a chloride ion content of 88 ppm, no detected sulfate, no detected metallic impurities, and a copper recovery rate of 90.3%.

[0118] Meanwhile, the waste resin powder from the reacted PCB circuit board was tested, and no copper was detected.

[0119] As can be seen from the comparison between Example 1 and Comparative Example 4, when the pH of the cuprous solution 2 is adjusted to be higher than 7 by ammonia in step S3, the copper recovery rate decreases significantly.

[0120] Comparative Example 5

[0121] The copper-containing etching waste liquid used in this comparative example was PCB etching waste liquid from a PCB factory, with the following composition: w(Cu): 10.87%; Fe: 28.5 mg / L; Ni: 5.3 mg / L; Zn: 15.9 mg / L; Ca: 8.6 mg / L; Mg: 8.8 mg / L; acidity: 2.33 mol / L; the PCB waste circuit board contained 20 wt% copper.

[0122] A method for producing cuprous oxide from waste PCB circuit boards and copper-containing etching waste liquid:

[0123] S1. Mix the PCB circuit board and copper-containing etching waste liquid (the weight ratio of PCB waste circuit board and copper-containing etching waste liquid is 1:2), and react at 25°C for 12 hours to obtain copper(II) solution 1.

[0124] S2. Add ammonia to cuprous solution 1 to adjust the pH to 5.5, centrifuge and wash to obtain cuprous oxide and ammonium chloride solution.

[0125] The ammonium chloride solution obtained in step S2 is evaporated and crystallized to obtain ammonium chloride byproduct.

[0126] The cuprous oxide obtained in this comparative example had a purity of 78.9%, a chloride ion content of 75 ppm, and no detected sulfate. The concentrations were: Fe: 28.2 mg / L; Ni: 5.3 mg / L; Zn: 15.8 mg / L; Ca: 8.5 mg / L; Mg: 8.8 mg / L, and the copper recovery rate was 91.5%.

[0127] Meanwhile, the waste PCB boards after the reaction were tested and found to contain 3wt% copper.

[0128] As can be seen from the comparison between Example 1 and Comparative Example 5, directly using waste PCB circuit boards leads to a significant decrease in the purity of cuprous oxide and the copper recovery rate.

[0129] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid, characterized by, The method comprises the following steps: S1, mixing PCB waste resin powder and copper-containing etching waste liquid, reacting to obtain cuprous solution 1; S2, adding phosphoric acid and ammonia water to the cuprous solution 1, stirring, pressure filtering to obtain cuprous solution 2 and impurity removal filter residue; S3, adding ammonia water to the cuprous solution 2, centrifuging and washing to obtain cuprous oxide and ammonium chloride solution; The adding amount of the ammonia water in step S2 is to adjust the pH of the cuprous solution 1 to 1.5-1.8; The adding amount of the ammonia water in step S3 is to adjust the pH of the cuprous solution 2 to 5.5-7.

2. The method of producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid according to claim 1, characterized by, The copper content of the PCB waste resin powder in step S1 is 0.5-1wt%.

3. The method of producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid according to claim 2, characterized by, The copper concentration of the copper-containing etching waste liquid in step S1 is 8-11wt%, and the acidity is 2-4mol / L.

4. The method of producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid according to claim 3, characterized by, The weight ratio of the PCB waste resin powder to the copper-containing etching waste liquid in step S1 is 80-120:

1.

5. The method of producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid according to claim 4, characterized by, The reaction temperature in step S1 is 25-30℃, and the reaction time is 10-12h.

6. The method of producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid according to claim 5, characterized by, The adding amount of the phosphoric acid in step S2 is 1.3-1.7 times of the total content of metal impurities in the copper-containing etching waste liquid.

7. The method of producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid according to claim 6, characterized by, The metal impurities in the copper-containing etching waste liquid include iron, nickel, zinc, calcium and magnesium.

8. The method of producing cuprous oxide from PCB circuit board waste resin powder and copper-containing etching waste liquid according to claim 7, characterized by, The stirring temperature in step S2 is 25-30℃, and the stirring time is 20-40min.

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