Device for dissolving metal from waste printed board and using method thereof

Abstract

The invention discloses a device for dissolving metal from a waste printed board and a using method, the device comprises a preparation cylinder, a dissolving cylinder and a recovery cylinder, the preparation cylinder is connected with the dissolving cylinder through a first pipeline, and the dissolving cylinder is connected with the recovery cylinder through a second pipeline. According to the recycling dissolving cylinder provided by the invention, metals in the waste printed boards and the leftover materials can be dissolved by adding the CuCl2-HCl-H2O2 system solution for dissolving, so that the metals in the waste printed boards and the leftover materials are recycled.

Description

Technical Field

[0001] The invention relates to the technical field of metal recovery from waste printed circuit boards, and more particularly to a device for dissolving metal from waste printed circuit boards and a method for using the device. Background Art

[0002] Waste printed circuit boards and waste scraps are mainly composed of glass fiber, resin and various metals. Waste printed circuit boards and waste scraps mainly contain common metals such as copper, nickel, lead and tin, as well as precious metals such as gold and palladium. The average content of metals in waste printed circuit boards and waste scraps is greater than 10%, while the content of rich ore metals in nature is 3%-5%, so waste printed circuit boards and waste scraps have a high recycling metal value, and can save resources and benefit the environment. The recycling technologies of waste printed circuit boards and waste scraps mainly include mechanical treatment, pyrolysis and chemical metallurgy. Chemical metallurgy includes pyrometallurgy and hydrometallurgy. In the recycling process, one of the methods can be used, or a combination of several methods can be used to dissolve the metal. Hydrometallurgy is a method of reacting waste printed circuit boards or waste scraps with strong oxidizing media such as hydrochloric acid, nitric acid, sulfuric acid or other mixtures to dissolve the metals in the waste printed circuit boards or waste scraps into the liquid phase, separate the metals from the non-metals, and then recover the metals in the liquid phase through reduction, electrolysis or extraction. Hydrometallurgy can directly dissolve the metals in waste printed circuit boards or waste scraps, and can also be used as a method of dissolving metals in the enriched metals after the waste printed circuit boards or waste scraps are separated by mechanical separation.

[0003] At present, the hydrometallurgical method used to dissolve metals from discarded printed circuit boards and waste scraps mainly uses nitric acid, hydrochloric acid, sulfuric acid and aqua regia solutions. This method can dissolve a wide variety of metals, but nitric acid and the like are prone to secondary pollution. H2SO4 and H2O2 can also dissolve metals, but the consumption of H2O2 is relatively large. There are other dissolution methods that mainly have the problems of few types of dissolved metals, secondary pollution and large material input. The above dissolution methods cannot be recycled;

[0004] The present invention designs a study on dissolving metals such as copper, nickel, lead, tin, gold and palladium from waste printed circuit boards and waste scraps using a CuCl2-HCl-H2O2 system solution. The method has low investment cost, high metal dissolving efficiency, and the system solution after dissolving the metal can be recycled by adding relevant reagents, and is environmentally friendly. Summary of the invention

[0005] In view of this, the present invention provides a device for dissolving metal from waste printed circuit boards using a CuCl2-HCl-H2O2 system solution and a method for using the device, which can effectively solve the technical problems in the background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A device for dissolving metal from waste printed circuit boards comprises a preparation tank, a dissolving tank and a recovery tank. The preparation tank is connected to the dissolving tank via a first pipeline, and the dissolving tank is connected to the recovery tank via a second pipeline.

[0008] Preferably, a first mechanical stirring device is provided in the preparation cylinder, and the first mechanical stirring device is vertically arranged at the center of the preparation cylinder.

[0009] Preferably, a second mechanical stirring device, an air stirring device and a heater are provided in the dissolution cylinder, wherein the second mechanical stirring device is vertically arranged at the center of the dissolution cylinder, the air stirring device is horizontally arranged at the bottom of the dissolution cylinder, and the heater is arranged on one side close to the inner wall of the dissolution cylinder.

[0010] Preferably, the first mechanical stirring device is 10 cm higher than the bottom of the preparation tank.

[0011] Preferably, the second mechanical stirring device is 10 cm higher than the bottom of the dissolution tank, the air stirring device is 10 cm higher than the bottom of the dissolution tank, and the second mechanical stirring device is not in contact with the air stirring device.

[0012] Preferably, the heater is 30 cm higher than the bottom of the dissolving tank and the distance from the inner wall of the dissolving tank is greater than 20 cm.

[0013] Preferably, a filter screen is provided in the dissolving tank, and the filter screen is provided between the air stirring device and the bottom of the dissolving tank.

[0014] Preferably, a first circulation pump is provided on the first pipeline, and a carbon core is provided in the first circulation pump;

[0015] The second pipeline is provided with a second circulation pump, and the second circulation pump is provided with a carbon core.

[0016] Preferably, a metal ion concentration detector is provided at the bottom of the dissolution tank, and the metal ion concentration detector, the first circulation pump and the second circulation pump are all electrically connected to an external controller.

[0017] Another object of the present invention is to provide a method for using a device for dissolving metal from waste printed circuit boards, comprising the following steps:

[0018] (1) Adding tap water of half the volume of the required CuCl2-HCl-H2O2 system solution into a preparation tank, dissolving CuCl2·2H2O in water and injecting it into the preparation tank, then dissolving HCl in water and injecting it into the preparation tank, injecting tap water into the preparation tank to the required volume, starting a first mechanical stirring device to stir, and completely dissolving the solution;

[0019] (2) Turn off the first mechanical stirring device, start the first circulation pump to pump the prepared solution in the preparation tank into the dissolution tank, start the second mechanical stirring device and the heater, when the solution temperature in the dissolution tank reaches 50°C, put the waste printed circuit boards and waste scraps into the dissolution tank, start the air stirring device, and when the metal ion concentration detector detects that the various metal ions reach the specified concentration, start the second circulation pump to pump the solution into the recovery tank to recover the metal.

[0020] Preferably, the concentration of the CuCl2·2H2O is 4 g / L, and the concentration of the HCl is 100 mL / L.

[0021] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0022] The recycling dissolving cylinder provided by the present invention can dissolve the metal in the waste printed circuit boards and scraps through a chemical liquid phase dissolving method, thereby realizing the recovery of the metal in the waste printed circuit boards and scraps;

[0023] The present invention achieves no waste liquid or waste water discharge and no environmental pollution;

[0024] The invention can dissolve metals in waste printed circuit boards and waste scraps. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 It is a structural diagram of the device of the present invention.

[0027] Among them, in the figure:

[0028] 1-preparation tank; 2-first mechanical stirring device; 3-first circulation pump; 4-first pipeline; 5-dissolution tank; 6-second mechanical stirring device; 7-air stirring device; 8-heater; 9-second circulation pump; 10-second pipeline; 11-recovery tank; 12-filter; 13-metal ion concentration detector. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in 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.

[0030] Example 1

[0031] like Figure 1 As shown, a device for dissolving metal from waste printed circuit boards includes a preparation cylinder 1, a dissolving cylinder 5 and a recovery cylinder 11, wherein the preparation cylinder 1 is connected to the dissolving cylinder 5 via a first pipeline 4, and the dissolving cylinder 5 is connected to the recovery cylinder 11 via a second pipeline 10.

[0032] In this embodiment, a first mechanical stirring device 2 is installed inside the preparation tank 1 . The first mechanical stirring device 2 is inserted deep into the preparation tank 1 and is 10 centimeters higher than the bottom of the preparation tank 1 .

[0033] In this embodiment, a second mechanical stirring device 6 , an air stirring device 7 and a heating device 8 are installed inside the dissolving tank 5 . The second mechanical stirring device 6 penetrates deep into the dissolving tank 5 and is 20 cm higher than the bottom of the dissolving tank 5 .

[0034] The air stirring device 7 is 10 cm higher than the bottom of the dissolving tank 5, and the air stirring device can increase the uniformity of the liquid.

[0035] The heating device 8 goes deep into the dissolving tank 5 and is 30 cm higher than the bottom of the dissolving tank 5 . The heating device 8 is 20 cm away from the edge of the dissolving tank 5 . A filter screen 12 is installed inside the dissolving tank 5 to retain the dissolved solids in the filter screen 12 .

[0036] In this embodiment, a first circulation pump 3 is provided at the center of the second pipeline 10. In this embodiment, a first circulation pump 3 is provided at the center of the first pipeline 4. A carbon core is installed in the first circulation pump 3. The first circulation pump 3 cooperates with the carbon core to play the role of circulating pump liquid and perform carbon adsorption and filtration on the liquid.

[0037] There is a second circulation pump 9, and a carbon core is also installed in the second circulation pump 9. The second circulation pump 9 cooperates with the carbon core to play the role of circulating pump liquid and perform carbon adsorption and filtration on the liquid.

[0038] In this embodiment, a metal ion concentration detector 13 is installed inside the dissolution tank 5, and the metal ion concentration detector 13, the first circulation pump 3, and the second circulation pump 9 are all electrically connected to an external controller.

[0039] Example 2

[0040] This embodiment provides a method for using the device for dissolving metal from waste printed circuit boards in Embodiment 1, comprising the following steps:

[0041] (1) Adding tap water of half the volume of the required CuCl2-HCl-H2O2 system solution into a preparation tank, dissolving CuCl2·2H2O with a concentration of 4 g / L in water and injecting it into the preparation tank, then dissolving HCl with a concentration of 100 ml / L in water and injecting it into the preparation tank, injecting tap water into the preparation tank to the required volume, starting a first mechanical stirring device to stir, and dissolving the solution completely;

[0042] (2) Turn off the first mechanical stirring device, start the first circulation pump to pump the prepared solution in the preparation tank into the dissolution tank, start the second mechanical stirring device and the heater, when the solution temperature in the dissolution tank reaches 50°C, put the waste printed circuit boards and waste scraps into the dissolution tank, start the air stirring device, and when the metal ion concentration detector detects that the various metal ions reach the specified concentration, start the second circulation pump to pump the solution into the recovery tank to recover the metal.

[0043] The reactions that occur in the dissolving tank are as follows:

[0044] (1) Reaction formula with copper:

[0045] Cu(s) 0 +Cu 2+ →2Cu + …………………………………………………………(1)

[0046] Cu + +nCl - →CuCln 1-n …………………………………………………………(2)

[0047] Cu 0 +Cu 2+ +2Cl - →2CuCl(s)(ΔG0(20℃)=-41kJ / mol)………(3)

[0048] Cu 0 +Cu 2+ +4Cl - →2CuCl 2- (ΔG0(20℃)=-25kJ / mol)………(4)

[0049] Cu 2+ and Cl - The generated ligand CuCln 2-n (2≤n≤4) has many forms.

[0050] (2) Reaction formula with lead:

[0051] Cu 2+ +Pb + (x+2)Cl - →CuCl2 - +PbCl x 2-x ………………………………(5)

[0052] X=1,2,3……

[0053] (3) Reaction formula with tin:

[0054] Cu 2+ +Sn + (x+2)Cl - →CuCl2 - +SnCl x 2-x ………………………………(6)

[0055] X=1,2,3……

[0056] (4) Reaction formula with nickel:

[0057] Cu 2+ +Ni + (x+2)Cl - →CuCl2 - +NiCl x 2-x ………………………………(7)

[0058] X=1,2,3……

[0059] (5) Reaction formula with palladium:

[0060] 2Cu 2+ +Pd 0 +8Cl - →2CuCl2 - +PdCl4 - …………………………………………(8)

[0061] (5) Reaction formula with H2O2:

[0062] 4CuCl2 - +H2O2+4H + →4Cu 2+ +8Cl - +3H2O……………………(9)4CuCl2 - +H2O2+4H + →4CuCl- +4Cl - +3H2O……………………(10)4CuCl2 - +H2O2+4H + →4CuCl 2(aq) +3H2O……………………(11)

[0063] (6) Reaction formula with O2:

[0064] 4CuCl2 - +O 2(aq) +4H + →4Cu 2+ +8Cl - +2H2O……………………(12)4CuCl2 - +O 2(aq) +4H + →4CuCl - +4Cl - +2H2O……………………(13)4CuCl2 - +O 2(aq) +4H + →4CuCl 2(aq) +2H2O……………………………………(14) The dissolution of metals after dissolution using the method of Example 2 is shown in Table 1:

[0065] Table 1

[0066] Metal Type Metal dissolution copper Completely dissolved nickel Completely dissolved lead Completely dissolved tin Completely dissolved palladium Completely dissolved gold Undissolved

[0067] The CuCl2-HCl-H2O2 system solution can dissolve the copper layer under the gold layer from the side of the discarded printed circuit board, so that the gold layer forms flakes and floats on the surface of the solution for filtration and recovery.

[0068] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0069] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for dissolving metal from waste printed circuit boards, characterized in that: It comprises a preparation cylinder, a dissolution cylinder and a recovery cylinder. The preparation cylinder is connected with the dissolution cylinder through a first pipeline, and the dissolution cylinder is connected with the recovery cylinder through a second pipeline.

2. The device for dissolving metal from waste printed circuit boards according to claim 1, characterized in that: A first mechanical stirring device is arranged in the preparation cylinder, and the first mechanical stirring device is vertically arranged at the center of the preparation cylinder.

3. The device for dissolving metal from waste printed circuit boards according to claim 2, characterized in that: A second mechanical stirring device, an air stirring device and a heater are arranged in the dissolving cylinder, wherein the second mechanical stirring device is vertically arranged at the center of the dissolving cylinder, the air stirring device is horizontally arranged at the bottom of the dissolving cylinder, and the heater is arranged on one side close to the inner wall of the dissolving cylinder.

4. The device for dissolving metal from waste printed circuit boards according to claim 2, characterized in that: The first mechanical stirring device is 10 cm higher than the bottom of the preparation tank.

5. The device for dissolving metal from waste printed circuit boards according to claim 3, characterized in that: The second mechanical stirring device is 10 cm higher than the bottom of the dissolution tank, the air stirring device is 10 cm higher than the bottom of the dissolution tank, and the second mechanical stirring device is not in contact with the air stirring device.

6. The device for dissolving metal from waste printed circuit boards according to claim 3, characterized in that: The heater is 30 cm higher than the bottom of the dissolving tank and the distance from the inner wall of the dissolving tank is greater than 20 cm.

7. A device for dissolving metal from waste printed circuit boards according to claim 5 or 6, characterized in that: A filter screen is arranged in the dissolving cylinder, and the filter screen is arranged between the air stirring device and the bottom of the dissolving cylinder.

8. The device for dissolving metal from waste printed circuit boards according to claim 7, characterized in that: The first pipeline is provided with a first circulation pump, and a carbon core is provided in the first circulation pump; the second pipeline is provided with a second circulation pump, and a carbon core is provided in the second circulation pump.

9. The device for dissolving metal from waste printed circuit boards according to claim 8, characterized in that: A metal ion concentration detector is arranged at the bottom of the dissolving tank, and the metal ion concentration detector, the first circulation pump and the second circulation pump are all electrically connected to an external controller.

10. The method for using the device for dissolving metal from waste printed circuit boards as claimed in claim 9, characterized in that: The following steps are involved: (1) Adding tap water of half the volume of the required CuCl2-HCl-H2O2 system solution into a preparation tank, dissolving CuCl2·2H2O in water and injecting it into the preparation tank, then dissolving HCl in water and injecting it into the preparation tank, injecting tap water into the preparation tank to the required volume, starting a first mechanical stirring device to stir, and completely dissolving the solution; (2) Turn off the first mechanical stirring device, start the first circulation pump to pump the prepared solution in the preparation tank into the dissolution tank, start the second mechanical stirring device and the heater, when the solution temperature in the dissolution tank reaches 50°C, put the waste printed circuit boards and waste scraps into the dissolution tank, start the air stirring device, and when the metal ion concentration detector detects that the various metal ions reach the specified concentration, start the second circulation pump to pump the solution into the recovery tank to recover the metal.

Images