Method for recovering metal copper from waste circuit board

Abstract

The invention discloses a method for recovering metal copper from a waste circuit board, which is suitable for a copper metal recovery system, and comprises an electrolytic bath, a positive electrode liquid collecting cylinder, a negative electrode liquid collecting cylinder, a copper dissolving liquid medicine storage pool, a dissolving pool, a filter tank and a high-copper liquid medicine storage pool, the electrolytic bath comprises an electrolytic cylinder, a positive electrode frame, a positive electrode plate and a negative electrode plate, the positive electrode frame is arranged in the electrolytic cylinder, the positive electrode plate is located in the positive electrode frame, and the negative electrode plate is located in the electrolytic cylinder; and an electrolyte is placed in the electrolysis cylinder and comprises Cu < 2 + >, SO4 < 2->, Fe < 3 + >, Fe < 2 + > and Cl <->. According to the scheme, the metal copper in the impure copper powder is converted into the copper ions through the solution containing the iron ions, then the copper ions are filtered, the obtained filtrate is electrolyzed, and therefore the metal copper with the high purity is obtained; in addition, the electric energy for obtaining the metal copper through electrolysis comes from an external power supply, can be directly used in the electrolysis process, is high in efficiency and can continuously act on production.

Description

Technical Field

[0001] The invention relates to the technical field of metal recovery, and in particular to a method for recovering metallic copper from waste circuit boards. Background Art

[0002] Printed circuit boards, as the foundation of the modern electronics industry, are the bridge and link between the components of various electronic products and are an indispensable component of any electronic product. However, as the production of circuit boards increases, the number of scrapped circuit boards also increases accordingly. If they are directly discarded, it will not only have a great negative impact on the environment, but also cause a huge waste of metal resources.

[0003] At present, the commonly used treatment method is to use a crusher to crush the circuit board to form copper-containing slag, and then use an air flow separator to screen the copper powder and fiber. However, the copper powder obtained by this method still contains a certain amount of non-metallic impurities, resulting in a low copper metal recovery rate. Summary of the invention

[0004] The purpose of the present invention is to provide a method for recovering metallic copper from waste circuit boards, which can effectively convert the low-value miscellaneous copper powder after the waste circuit boards are crushed into metallic copper plates with higher purity, and the recovery method has high efficiency and can be continuously used in production to overcome the shortcomings of the prior art.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A method for recovering metallic copper from waste circuit boards, applicable to a copper metal recovery system, wherein the copper metal recovery system comprises an electrolytic cell, a cathode liquid collection tank, a cathode liquid collection tank, a copper-dissolving solution storage tank, a dissolving tank, a filtering tank and a high-copper solution storage tank;

[0007] The electrolytic cell comprises an electrolytic cylinder, a positive electrode frame, an anode sheet and a cathode sheet, wherein the positive electrode frame is arranged inside the electrolytic cylinder, the anode sheet is arranged inside the positive electrode frame, and the cathode sheet is arranged inside the electrolytic cylinder; an electrolyte is placed inside the electrolytic cylinder, and the electrolyte comprises Cu 2+ 、SO4 2- , Fe 3+ , Fe 2+ and Cl - ;

[0008] The positive electrode frame and the positive electrode liquid collecting cylinder are sequentially connected along the conveying direction of the positive electrode liquid, and the positive electrode liquid circulates between the positive electrode frame and the positive electrode liquid collecting cylinder;

[0009] The electrolytic cylinder and the cathode liquid collection cylinder are sequentially connected along the conveying direction of the electrolyte, and the electrolyte circulates between the electrolytic cylinder and the cathode liquid collection cylinder;

[0010] The cathode liquid collection tank, the copper dissolving solution storage tank, the dissolving tank, the filtering tank, the high copper solution storage tank and the cathode liquid collection tank are connected in sequence;

[0011] The method for recovering metallic copper from waste circuit boards comprises the following steps:

[0012] A. crushing the waste circuit boards to obtain miscellaneous copper powder; the miscellaneous copper powder comprises copper and fiber;

[0013] B. preparing an electrolyte, adding the electrolyte to the electrolytic cell and then energizing for electrolysis;

[0014] C. Detecting the ORP value of the cathode liquid in the cathode liquid collection tank, and when the ORP value of the cathode liquid reaches a preset copper dissolving value, transporting the cathode liquid in the cathode liquid collection tank to the copper dissolving solution storage tank for storage to obtain a copper dissolving solution;

[0015] D. Adding the copper dissolving solution and the impure copper powder into the dissolving tank, stirring to obtain a dissolving solution; filtering the dissolving solution through the filter tank, and transporting the filtrate to the high-copper solution storage tank for storage to obtain a high-copper solution;

[0016] E. Detecting the specific gravity of the electrolyte in the cathode liquid collection tank, and when the specific gravity of the electrolyte is lower than the preset value for copper supplementation, transporting the high copper solution in the high copper solution storage tank to the cathode liquid collection tank for copper supplementation;

[0017] F. When the thickness of the metal copper plate obtained from the cathode sheet reaches 2 to 3 mm, the electrolytic cell is powered off and the metal copper plate is peeled off.

[0018] Preferably, the copper metal recovery system further comprises a hydrogen peroxide storage tank, and the outlet of the hydrogen peroxide storage tank is interconnected with the inlet of the dissolution tank, and the hydrogen peroxide storage tank is used to input hydrogen peroxide into the dissolution tank.

[0019] Preferably, step D further comprises:

[0020] The ORP value of the dissolved liquid in the dissolution tank is detected, and when the ORP value of the dissolved liquid is lower than a preset oxidation value, the hydrogen peroxide in the hydrogen peroxide storage tank is transported to the dissolution tank.

[0021] Preferably, the oxidation preset value is 400mV.

[0022] Preferably, the copper dissolution preset value is 380-400 mV.

[0023] Preferably, the copper supplementation preset value is 1.12-1.18.

[0024] Preferably, the electrolyte contains 30-40 g / L of Cu 2+ , 200~250g / L SO4 2- , 15~30g / L Fe 3+ 、35~50g / LFe 2+ and 40-90 mg / L Cl - .

[0025] Preferably, in step D, the stirring temperature is 30-40° C., and the stirring speed is 40-60 r / min.

[0026] Preferably, in step B, the current density of the electrolysis is 2 to 3 A / dm 2 .

[0027] The technical solution provided by the present invention may include the following beneficial effects:

[0028] In this scheme, the metallic copper in the miscellaneous copper powder is converted into copper ions by using a solution containing iron ions, and then filtered, and the obtained filtrate is electrolyzed to obtain metallic copper with higher purity. In addition, in this scheme, the electric energy for electrolyzing the metallic copper comes from an external power supply, which can be directly used in the electrolysis process, has high efficiency, and can be continuously used in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the copper metal recovery system in the present invention.

[0030] Among them: electrolysis cylinder 11, positive electrode frame 12, anode sheet 13, cathode sheet 14, positive electrode liquid collection cylinder 2, negative electrode liquid collection cylinder 3, copper dissolving solution storage tank 4, dissolution tank 5, filter tank 6, high copper solution storage tank 7, hydrogen peroxide storage tank 8. DETAILED DESCRIPTION

[0031] A method for recovering metallic copper from waste circuit boards, applicable to a copper metal recovery system, wherein the copper metal recovery system comprises an electrolytic cell, a cathode liquid collection tank 2, a cathode liquid collection tank 3, a copper-dissolving solution storage tank 4, a dissolving tank 5, a filtering tank 6 and a high-copper solution storage tank 7;

[0032] The electrolytic cell comprises an electrolytic cylinder 11, a positive electrode frame 12, an anode sheet 13 and a cathode sheet 14, wherein the positive electrode frame 12 is arranged inside the electrolytic cylinder 11, the anode sheet 13 is located inside the positive electrode frame 12, and the cathode sheet 14 is located inside the electrolytic cylinder 11; an electrolyte is placed inside the electrolytic cylinder 11, and the components of the electrolyte include Cu 2+ 、SO42- , Fe 3+ , Fe 2+ and Cl - ;

[0033] The positive electrode frame 12 and the positive electrode liquid collecting cylinder 2 are sequentially connected along the conveying direction of the positive electrode liquid, and the positive electrode liquid circulates between the positive electrode frame 12 and the positive electrode liquid collecting cylinder 2;

[0034] The electrolytic cylinder 11 and the cathode liquid collection cylinder 3 are sequentially connected along the conveying direction of the electrolyte, and the electrolyte circulates between the electrolytic cylinder 11 and the cathode liquid collection cylinder 3;

[0035] The cathode liquid collection cylinder 2, the copper dissolving solution storage tank 4, the dissolving tank 5, the filtering tank 6, the high copper solution storage tank 7 and the cathode liquid collection cylinder 3 are connected in sequence;

[0036] The method for recovering metallic copper from waste circuit boards comprises the following steps:

[0037] A. crushing the waste circuit boards to obtain miscellaneous copper powder; the miscellaneous copper powder comprises copper and fiber;

[0038] B. preparing an electrolyte, adding the electrolyte to the electrolytic cell and then energizing for electrolysis;

[0039] C. Detecting the ORP value of the cathode liquid in the cathode liquid collection cylinder 2. When the ORP value of the cathode liquid reaches a preset copper dissolving value, transporting the cathode liquid in the cathode liquid collection cylinder 2 to the copper dissolving solution storage tank 4 for storage to obtain a copper dissolving solution;

[0040] D. Add the copper dissolving solution and the impure copper powder into the dissolving tank 5, and stir to obtain a dissolved solution; after filtering the dissolved solution through the filter tank 6, transport the filtrate to the high-copper solution storage tank 7 for storage to obtain a high-copper solution;

[0041] E. Detecting the specific gravity of the electrolyte in the cathode liquid collection cylinder 3, and when the specific gravity of the electrolyte is lower than the preset value for copper supplementation, transporting the high copper solution in the high copper solution storage tank 7 to the cathode liquid collection cylinder 3 for copper supplementation;

[0042] F. When the thickness of the metal copper plate obtained by the cathode sheet 14 reaches 2 to 3 mm, the electrolytic cell is powered off and the metal copper plate is peeled off.

[0043] At present, the commonly used method for processing waste circuit boards is to use a crusher to crush the circuit boards to form copper-containing slag, and then use an air flow separator to screen the copper powder and fibers. However, the copper powder obtained by this method still contains a certain amount of non-metallic impurities, resulting in a low copper metal recovery rate.

[0044] Therefore, in order to effectively convert the low-value copper powder after the waste circuit boards are crushed into high-purity copper metal plates, the present technical solution proposes a method for recovering copper metal from waste circuit boards, which is suitable for Figure 1 The copper metal recovery system shown in the figure, since the raw materials in the miscellaneous copper powder are mainly copper and fiber, this scheme uses a solution containing iron ions to convert the metallic copper in the miscellaneous copper powder into copper ions and then filters them, and electrolyzes the obtained filtrate to obtain metallic copper with higher purity; in addition, the electric energy for electrolyzing the metallic copper in this scheme comes from an external power supply, which can be directly used in the electrolysis process, has high efficiency, and can be continuously used in production.

[0045] Specifically, the present invention firstly crushes the waste circuit boards to obtain the miscellaneous copper powder containing copper and fiber; then 2+ 、SO4 2- , Fe 3+ , Fe 2+ and Cl - The electrolyte is placed in the electrolytic cell and powered on for electrolysis. It should be noted that during the electrolysis process of the electrolytic cell, the electrode reactions are:

[0046] Cathode: Cu 2+ +2e-=Cu,

[0047] Anode: Fe 2+ -2e-=Fe 3+ ,

[0048] During the electrolysis process, the ORP value of the cathode liquid in the cathode liquid collection cylinder 2 is detected. When the ORP value of the cathode liquid reaches the preset value for copper dissolution, the cathode liquid in the cathode liquid collection cylinder 2 is transported to the copper dissolution solution storage tank 4 for storage to obtain Fe 3+ The copper dissolving solution contains a large amount of copper, and causes the following copper dissolving reaction to occur in the dissolving tank 5:

[0049] Cu+2Fe 3+ =Cu 2+ +2Fe 2+ ,

[0050] In the copper dissolving reaction in the dissolving tank 5, the copper in the copper powder is converted into copper ions, and the insoluble fibers in the copper powder are filtered by the filter tank 6, so that Cu can be obtained in the high copper solution storage tank 7. 2+ High-copper solution with a higher content; finally, when the specific gravity of the electrolyte reaches the preset value of copper supplement, the high-copper solution is transported to the electrolysis process for electrolysis, and a metal copper plate with a higher purity can be obtained in the cathode sheet 14.

[0051] It should be noted that the ORP value refers to the oxidation-reduction potential, which is a parameter that measures the relative strength of oxidants and reductants in water or solutions. It reflects the relative strength of oxidants and reductants in the water environment and is usually expressed in millivolts (mV).

[0052] To further illustrate, the copper metal recovery system also includes a hydrogen peroxide storage tank 8 , and the outlet of the hydrogen peroxide storage tank 8 is interconnected with the inlet of the dissolution tank 5 , and the hydrogen peroxide storage tank 8 is used to input hydrogen peroxide into the dissolution tank 5 .

[0053] In a preferred embodiment of the present technical solution, a hydrogen peroxide storage tank 8 is further provided in the copper metal recovery system for feeding hydrogen peroxide into the dissolution tank 5. The replenishment of hydrogen peroxide in the dissolution tank 5 is beneficial to oxidizing Fe 2+ , thereby assisting the dissolution of metallic copper in the miscellaneous copper powder to improve the copper dissolving efficiency of the dissolution tank 5.

[0054] To further illustrate, step D also includes:

[0055] The ORP value of the dissolved liquid in the dissolution tank 5 is detected. When the ORP value of the dissolved liquid is lower than a preset oxidation value, the hydrogen peroxide in the hydrogen peroxide storage tank 8 is transported to the dissolution tank 5 .

[0056] As a better embodiment of the above embodiment, when the ORP value of the dissolved liquid is lower than the preset oxidation value, the hydrogen peroxide in the hydrogen peroxide storage tank 8 is transported to the dissolving tank 5, and the timing of adding hydrogen peroxide is determined by detecting the ORP value of the dissolved liquid, which is more conducive to improving the controllability of the recovery method and avoiding the waste of hydrogen peroxide.

[0057] To further illustrate, the oxidation preset value is 400mV.

[0058] This is to improve the oxidizability of the solution in the dissolution tank 5 .

[0059] To further illustrate, the copper dissolution preset value is 380-400 mV.

[0060] To further illustrate, the preset value of copper supplementation is 1.12-1.18.

[0061] The above specific gravity corresponds to the amount of Cu in the electrolyte. 2+ The content is 30-40 g / L. When the copper ion content in the electrolyte is too low, it is easy to reduce the purity of the copper plate obtained by electrolysis in the cathode sheet 14 and the current efficiency of the electrolytic cell. Therefore, in order to ensure the purity of the copper plate and the current efficiency of the electrolytic cell, the preset value of copper supplementation is preferably 1.12-1.18 in this solution.

[0062] Further, the electrolyte comprises 30-40 g / L of Cu 2+, 200~250g / L SO4 2- , 15~30g / L Fe 3+ 、35~50g / LFe 2+ and 40-90 mg / L Cl - .

[0063] In another preferred embodiment of the present technical solution, the composition and concentration of the electrolyte are also optimized. 2- It mainly enhances the conductivity of the solution and prevents copper sulfate from hydrolyzing into copper hydroxide precipitation. If the sulfuric acid concentration is too low, the dispersion ability of the electrolyte may decrease and the bright range of the copper layer may decrease. If the sulfuric acid concentration is too high, although the dispersion ability of the electrolyte is good, the ductility of the copper layer may decrease. 3+ When the content is high, it will react with the metallic copper produced by electrolysis, reducing the efficiency of cathode electrolysis. However, since a certain amount of Fe is required in the copper dissolution process, 2+ Oxidized to Fe 3+ Therefore, this scheme will be Fe in the electrolyte 3+ and Fe 2+ The total is preferably 50 to 80 g / L.

[0064] To further illustrate, in step D, the stirring temperature is 30-40° C., and the stirring speed is 40-60 r / min.

[0065] Furthermore, in this solution, the temperature of the stirring process in the dissolution tank 5 is preferably set to 30-40°C, at which the copper powder can be well dissolved; in addition, the speed of the stirring process in the dissolution tank 5 is also preferably set to 40-60r / min. If the speed is too low, the copper powder dissolves slowly. If the speed is too high, when there are more solids in the dissolution tank 5, it is difficult to stir.

[0066] Preferably, the stirring speed is 50 r / min.

[0067] Further, in step B, the current density of the electrolysis is 2 to 3 A / dm 2 .

[0068] The current density in the electrolysis process is preferably 2 to 3 A / dm 2 , a relatively strong and flat copper plate can be electrolyzed at this current density. If the current density is too high, copper powder may appear on the surface of the copper plate, affecting the flatness of the copper layer; if the current density is too low, the electrolysis efficiency is reduced, and it is difficult to electrolyze copper.

[0069] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0070] Example 1

[0071] A copper metal recovery system comprises an electrolytic cell, a cathode liquid collection tank 2, a cathode liquid collection tank 3, a copper-dissolving solution storage tank 4, a dissolving tank 5, a filtering tank 6 and a high-copper solution storage tank 7.

[0072] The electrolytic cell comprises an electrolytic cylinder 11, a positive electrode frame 12, an anode sheet 13 and a cathode sheet 14, wherein the positive electrode frame 12 is arranged inside the electrolytic cylinder 11, the anode sheet 13 is located inside the positive electrode frame 12, and the cathode sheet 14 is located inside the electrolytic cylinder 11; an electrolyte is placed inside the electrolytic cylinder 11, and the electrolyte comprises 30 g / L of Cu 2+ , 200g / L SO4 2- , 15g / L Fe 3+ 、35g / LFe 2+ and 40 mg / L Cl - .

[0073] The positive electrode frame 12 and the positive electrode liquid collecting cylinder 2 are sequentially connected along the conveying direction of the positive electrode liquid, and the positive electrode liquid circulates between the positive electrode frame 12 and the positive electrode liquid collecting cylinder 2;

[0074] The electrolytic cylinder 11 and the cathode liquid collection cylinder 3 are sequentially connected along the conveying direction of the electrolyte, and the electrolyte circulates between the electrolytic cylinder 11 and the cathode liquid collection cylinder 3;

[0075] The cathode liquid collection cylinder 2, the copper dissolving solution storage tank 4, the dissolving tank 5, the filtering tank 6, the high copper solution storage tank 7 and the cathode liquid collection cylinder 3 are connected in sequence.

[0076] The above copper metal recovery system is used to recover the copper metal in the waste circuit boards, including the following steps:

[0077] A. Crush the waste circuit boards to obtain miscellaneous copper powder including copper and fiber; then, divide the miscellaneous copper powder into three equal parts.

[0078] B. Prepare an electrolyte, add the electrolyte to the electrolytic cell and then conduct electrolysis, wherein the current density of the electrolysis is 2A / dm 2 ;

[0079] C. Detecting the ORP value of the cathode liquid in the cathode liquid collection cylinder 2. When the ORP value of the cathode liquid reaches 380 mV, transporting the cathode liquid in the cathode liquid collection cylinder 2 to the copper-dissolving solution storage tank 4 for storage to obtain copper-dissolving solution;

[0080] D. Add the copper-dissolving solution and the first portion of the miscellaneous copper powder in step A into the dissolving tank 5, and stir to obtain a dissolved solution; after filtering the dissolved solution through the filter tank 6, transport the filtrate to the high-copper solution storage tank 7 for storage to obtain a high-copper solution;

[0081] E. Detecting the specific gravity of the electrolyte in the cathode liquid collection cylinder 3. When the specific gravity of the electrolyte is lower than 1.12, transporting the high-copper solution in the high-copper solution storage tank 7 to the cathode liquid collection cylinder 3 for copper supplementation;

[0082] F. When the thickness of the metal copper plate obtained by the cathode sheet 14 reaches 2 mm, the electrolytic cell is powered off and the metal copper plate is peeled off; wherein the purity of the metal copper plate is 99%.

[0083] Example 2

[0084] A copper metal recovery system comprises an electrolytic cell, a cathode liquid collection tank 2, a cathode liquid collection tank 3, a copper-dissolving solution storage tank 4, a dissolving tank 5, a filtering tank 6 and a high-copper solution storage tank 7.

[0085] The electrolytic cell comprises an electrolytic cylinder 11, a positive electrode frame 12, an anode sheet 13 and a cathode sheet 14, wherein the positive electrode frame 12 is arranged inside the electrolytic cylinder 11, the anode sheet 13 is located inside the positive electrode frame 12, and the cathode sheet 14 is located inside the electrolytic cylinder 11; an electrolyte is placed inside the electrolytic cylinder 11, and the composition of the electrolyte comprises 35 g / L of Cu 2+ , 225g / L SO4 2- , 20g / L Fe 3+ 、40g / LFe 2+ and 60 mg / L Cl - .

[0086] The positive electrode frame 12 and the positive electrode liquid collecting cylinder 2 are sequentially connected along the conveying direction of the positive electrode liquid, and the positive electrode liquid circulates between the positive electrode frame 12 and the positive electrode liquid collecting cylinder 2;

[0087] The electrolytic cylinder 11 and the cathode liquid collection cylinder 3 are sequentially connected along the conveying direction of the electrolyte, and the electrolyte circulates between the electrolytic cylinder 11 and the cathode liquid collection cylinder 3;

[0088] The cathode liquid collection cylinder 2, the copper dissolving solution storage tank 4, the dissolving tank 5, the filtering tank 6, the high copper solution storage tank 7 and the cathode liquid collection cylinder 3 are connected in sequence.

[0089] The above copper metal recovery system is used to recover the copper metal in the waste circuit boards, including the following steps:

[0090] A. Obtain the second portion of miscellaneous copper powder in step A of Example 1;

[0091] B. Prepare an electrolyte, add the electrolyte to the electrolytic cell and then conduct electrolysis, wherein the current density of the electrolysis is 2.5A / dm 2 ;

[0092] C. Detecting the ORP value of the cathode liquid in the cathode liquid collection cylinder 2. When the ORP value of the cathode liquid reaches 390 mV, transporting the cathode liquid in the cathode liquid collection cylinder 2 to the copper-dissolving solution storage tank 4 for storage to obtain copper-dissolving solution;

[0093] D. Add the copper dissolving solution and the second portion of the miscellaneous copper powder in step A into the dissolving tank 5, and stir to obtain a dissolved solution; after filtering the dissolved solution through the filter tank 6, transport the filtrate to the high-copper solution storage tank 7 for storage to obtain a high-copper solution;

[0094] E. Detecting the specific gravity of the electrolyte in the cathode liquid collection cylinder 3, and when the specific gravity of the electrolyte is lower than 1.15, transporting the high copper solution in the high copper solution storage tank 7 to the cathode liquid collection cylinder 3 for copper supplementation;

[0095] F. When the thickness of the metal copper plate obtained by the cathode sheet 14 reaches 2.5 mm, the electrolytic cell is powered off and the metal copper plate is peeled off; wherein the purity of the metal copper plate is 99%.

[0096] Example 3

[0097] A copper metal recovery system comprises an electrolytic cell, a cathode liquid collection tank 2, a cathode liquid collection tank 3, a copper dissolving solution storage tank 4, a dissolving tank 5, a filtering tank 6, a high copper solution storage tank 7 and a hydrogen peroxide storage tank 8.

[0098] The electrolytic cell comprises an electrolytic cylinder 11, a positive electrode frame 12, an anode sheet 13 and a cathode sheet 14, wherein the positive electrode frame 12 is arranged inside the electrolytic cylinder 11, the anode sheet 13 is located inside the positive electrode frame 12, and the cathode sheet 14 is located inside the electrolytic cylinder 11; an electrolyte is placed inside the electrolytic cylinder 11, and the electrolyte comprises 40 g / L of Cu 2+ , 250g / L SO4 2- , 30g / L Fe 3+ 、50g / LFe 2+ and 90 mg / L Cl - .

[0099] The positive electrode frame 12 and the positive electrode liquid collecting cylinder 2 are sequentially connected along the conveying direction of the positive electrode liquid, and the positive electrode liquid circulates between the positive electrode frame 12 and the positive electrode liquid collecting cylinder 2;

[0100] The electrolytic cylinder 11 and the cathode liquid collection cylinder 3 are sequentially connected along the conveying direction of the electrolyte, and the electrolyte circulates between the electrolytic cylinder 11 and the cathode liquid collection cylinder 3;

[0101] The cathode liquid collection cylinder 2, the copper dissolving solution storage tank 4, the dissolving tank 5, the filtering tank 6, the high copper solution storage tank 7 and the cathode liquid collection cylinder 3 are connected in sequence.

[0102] The outlet of the hydrogen peroxide storage tank 8 is connected to the inlet of the dissolution tank 5 , and the hydrogen peroxide storage tank 8 is used to input hydrogen peroxide into the dissolution tank 5 .

[0103] The above copper metal recovery system is used to recover the copper metal in the waste circuit boards, including the following steps:

[0104] A. Obtain the third portion of miscellaneous copper powder in step A of Example 1;

[0105] B. Prepare an electrolyte, add the electrolyte to the electrolytic cell and then conduct electrolysis, wherein the current density of the electrolysis is 3A / dm 2 ;

[0106] C. Detecting the ORP value of the cathode liquid in the cathode liquid collection cylinder 2. When the ORP value of the cathode liquid reaches 400 mV, transporting the cathode liquid in the cathode liquid collection cylinder 2 to the copper-dissolving solution storage tank 4 for storage to obtain the copper-dissolving solution;

[0107] D. Add the copper-dissolving solution and the third portion of the miscellaneous copper powder in step A into the dissolving tank 5, and stir to obtain a dissolved solution; after filtering the dissolved solution through the filter tank 6, transport the filtrate to the high-copper solution storage tank 7 for storage to obtain a high-copper solution;

[0108] The ORP value of the dissolved liquid in the dissolution tank 5 is detected, and when the ORP value of the dissolved liquid is lower than 400 mV, the hydrogen peroxide in the hydrogen peroxide storage tank 8 is transported to the dissolution tank 5 .

[0109] E. Detecting the specific gravity of the electrolyte in the cathode liquid collection cylinder 3, and when the specific gravity of the electrolyte is lower than 1.18, transporting the high-copper solution in the high-copper solution storage tank 7 to the cathode liquid collection cylinder 3 for copper supplementation;

[0110] F. When the thickness of the metal copper plate obtained by the cathode sheet 14 reaches 3 mm, the electrolytic cell is powered off and the metal copper plate is peeled off; wherein the purity of the metal copper plate is 99%.

[0111] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A method for recovering metallic copper from waste circuit boards, characterized in that: Applicable to a copper metal recovery system, the copper metal recovery system comprising an electrolytic cell, a cathode liquid collection tank, a cathode liquid collection tank, a copper-dissolving solution storage tank, a dissolving tank, a filtering tank and a high-copper solution storage tank; The electrolytic cell comprises an electrolytic cylinder, a positive electrode frame, an anode sheet and a cathode sheet, wherein the positive electrode frame is arranged inside the electrolytic cylinder, the anode sheet is arranged inside the positive electrode frame, and the cathode sheet is arranged inside the electrolytic cylinder; an electrolyte is placed inside the electrolytic cylinder, and the electrolyte comprises Cu 2+ 、SO4 2- , Fe 3+ , Fe 2+ and Cl - ; The positive electrode frame and the positive electrode liquid collecting cylinder are sequentially connected along the conveying direction of the positive electrode liquid, and the positive electrode liquid circulates between the positive electrode frame and the positive electrode liquid collecting cylinder; The electrolytic cylinder and the cathode liquid collection cylinder are sequentially connected along the conveying direction of the electrolyte, and the electrolyte circulates between the electrolytic cylinder and the cathode liquid collection cylinder; The cathode liquid collection tank, the copper dissolving solution storage tank, the dissolving tank, the filtering tank, the high copper solution storage tank and the cathode liquid collection tank are connected in sequence; The method for recovering metallic copper from waste circuit boards comprises the following steps: A. crushing the waste circuit boards to obtain miscellaneous copper powder; the miscellaneous copper powder comprises copper and fiber; B. preparing an electrolyte, adding the electrolyte to the electrolytic cell and then energizing for electrolysis; C. Detecting the ORP value of the cathode liquid in the cathode liquid collection tank, and when the ORP value of the cathode liquid reaches a preset copper dissolving value, transporting the cathode liquid in the cathode liquid collection tank to the copper dissolving solution storage tank for storage to obtain a copper dissolving solution; D. Adding the copper dissolving solution and the impure copper powder into the dissolving tank, stirring to obtain a dissolving solution; filtering the dissolving solution through the filter tank, and transporting the filtrate to the high-copper solution storage tank for storage to obtain a high-copper solution; E. Detecting the specific gravity of the electrolyte in the cathode liquid collection tank, and when the specific gravity of the electrolyte is lower than the preset value for copper supplementation, transporting the high copper solution in the high copper solution storage tank to the cathode liquid collection tank for copper supplementation; F. When the thickness of the metal copper plate obtained from the cathode sheet reaches 2 to 3 mm, the electrolytic cell is powered off and the metal copper plate is peeled off.

2. A method for recovering metallic copper from waste circuit boards according to claim 1, characterized in that: The copper metal recovery system also includes a hydrogen peroxide storage tank, and the outlet of the hydrogen peroxide storage tank is connected to the inlet of the dissolution tank, and the hydrogen peroxide storage tank is used to input hydrogen peroxide into the dissolution tank.

3. The method for recovering metallic copper from waste circuit boards according to claim 2, characterized in that: Step D also includes: The ORP value of the dissolved liquid in the dissolution tank is detected, and when the ORP value of the dissolved liquid is lower than a preset oxidation value, the hydrogen peroxide in the hydrogen peroxide storage tank is transported to the dissolution tank.

4. The method for recovering metallic copper from waste circuit boards according to claim 3, characterized in that: The oxidation preset value is 400mV.

5. The method for recovering metallic copper from waste circuit boards according to claim 1, characterized in that: The copper dissolution preset value is 380-400 mV.

6. The method for recovering metallic copper from waste circuit boards according to claim 1, characterized in that: The copper supplementation preset value is 1.12-1.

18.

7. The method for recovering metallic copper from waste circuit boards according to claim 1, characterized in that: The electrolyte comprises 30-40 g / L of Cu 2+ , 200~250g / L SO4 2- , 15~30g / L Fe 3+ 、35~50g / LFe 2+ and 40-90 mg / L Cl - .

8. The method for recovering metallic copper from waste circuit boards according to claim 1, characterized in that: In step D, the stirring temperature is 30-40° C., and the stirring speed is 40-60 r / min.

9. The method for recovering metallic copper from waste circuit boards according to claim 1, characterized in that: In step B, the current density of the electrolysis is 2 to 3 A / dm 2 .

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