Waste aluminum electrolytic capacitor recovery method

Abstract

The invention relates to the technical field of industrial waste resourceful treatment, in particular to a waste aluminum electrolytic capacitor recycling method which comprises the steps that waste A is obtained through a crusher, the waste A is conveyed to a cyclone dust collector to recycle crushed dust, and waste B is conveyed to a first-stage air separation machine; the waste material B is separated through a first-stage air separation machine to obtain electrolytic paper and a waste material C, the electrolytic paper is fed into a hydraulic crusher through a conveying belt to be crushed, a waste material D at a discharging opening of the hydraulic crusher is washed through a 6S shaking table to obtain a solid-liquid mixture, the solid-liquid mixture is fed into a filter press to obtain an electrolytic paper filter cake and press filtrate, and the press filtrate is subjected to chemical treatment; aluminum foil and waste E are separated from the waste C through a second-stage air separation machine; a guide pin and a waste material F are separated from the waste material E through a magnetic separator; aluminum sheets and rubber plugs are separated from the waste material F through a color sorter. According to the waste aluminum electrolytic capacitor recycling method, the waste aluminum electrolytic capacitor is harmlessly treated in a physical and chemical combined treatment mode, and the good separation and recycling effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of industrial waste resource utilization technology, and more specifically, to a method for recycling waste aluminum electrolytic capacitors. Background Technology

[0002] Aluminum electrolytic capacitors, hailed as the "industrial rice" of the modern electronics and information industry, are electronic components widely used in household appliances, automotive electronics, new energy vehicles, and industrial control. Aluminum electrolytic capacitors mainly consist of an aluminum cylindrical shell, a core, a rubber stopper, and a sleeve. The core is made of four layers of overlapping and wound aluminum foil, electrolytic paper, and cathode foil. The anode and cathode foils are connected at one end by positive and negative electrode pins with aluminum tongues. Each pin consists of a pin body and an aluminum tongue. The pin body is made of tin-plated copper-clad wire welded to one end with an aluminum tongue. The pin body is riveted to the aluminum foil via the aluminum tongue. After the core is impregnated with electrolyte, it is sealed with an aluminum shell and a rubber stopper, forming an electrolytic capacitor. A large number of waste aluminum electrolytic capacitors are generated during the production process and the recycling of various electronic appliances.

[0003] Currently, the treatment of these waste materials generally adopts direct incineration or high-temperature pyrolysis methods, which generate a large amount of secondary pollution while recovering valuable metals; some simple physical crushing methods are also used, but the analysis is crude and cannot achieve complete separation. For example, the existing Chinese patent announcement number CN110152854A discloses a method for recycling aluminum electrolytic capacitor waste, including the following steps: (1) The aluminum electrolytic capacitor waste is crushed by a crushing mechanism, which includes a box body, a crushing chamber at the top of the box body, a feed inlet at the top of the crushing chamber, a discharge outlet at the bottom, a screen above the discharge outlet, a crushing roller driven by a power source inside the crushing chamber, a moving blade installed on the crushing roller, and a fixed blade installed on the crushing chamber body; during operation, the fixed blade and the moving blade shear the waste material. The process involves: (1) Chopping to break down the waste aluminum electrolytic capacitors into metallic aluminum, conductor pins, electrolytic paper, and rubber stoppers; (2) Separating the conductor pins using a magnetic separation mechanism; (3) Separating the waste after the conductor pins are separated into metallic aluminum using an eddy current separation mechanism; (4) Separating the waste after the metallic aluminum is separated into rubber stoppers and paper using a sorting mechanism. The sorting mechanism includes a conveyor belt connected to the outlet of the eddy current separation mechanism, with the conveyor belt moving at an acute angle of 5° to 20° to the horizontal. Since the rubber stoppers are cylindrical, they roll off the conveyor belt into a rubber stopper collection hopper, while the electrolytic paper is fed into an electrolytic paper collection hopper by the conveyor belt. While this recycling method separates valuable metals from the waste electrolytic capacitors, it also generates a large amount of electrolytic paper impregnated with electrolyte. Incinerating this electrolyte-impregnated electrolytic paper still produces significant secondary pollution. Summary of the Invention

[0004] This invention provides a method for recycling waste aluminum electrolytic capacitors. It uses a combination of physical and chemical treatment to harmlessly process the waste aluminum electrolytic capacitors, separating them into electrolytic paper, aluminum foil, aluminum sheets, guide needles, and rubber stoppers, etc., which has a better separation and recycling effect, and can also effectively recycle the filtrate.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for recycling waste aluminum electrolytic capacitors is provided, including the following steps:

[0007] (1) Waste aluminum electrolytic capacitors are crushed by a crusher to obtain waste material A. The crushed and separated waste material A is transported by a negative pressure fan through a duct to the cyclone dust collector at the rear end of the crusher. The upper air outlet of the cyclone dust collector is connected to a pulse dust collector to recover crushed dust. The waste material B at the lower outlet is sent to the first-stage air separation unit via a conveyor belt.

[0008] (2) Waste B is separated into electrolytic paper and waste C by a primary air separator. The electrolytic paper is fed into a hydraulic crusher for crushing by a conveyor belt. A 6S shaking table and a filter press connected by a diaphragm pump are installed below the discharge port of the hydraulic crusher. Waste D from the discharge port of the hydraulic crusher is washed by the 6S shaking table to obtain a solid-liquid mixture. The solid-liquid mixture is fed into the filter press by a diaphragm pump to obtain an electrolytic paper filter cake and a filter liquid containing electrolyte. The filter liquid is chemically treated.

[0009] (3) The waste C is separated into aluminum foil and waste E by a two-stage air separation unit;

[0010] (4) The waste material E is separated into guide needles and waste material F by a magnetic separator;

[0011] (5) The waste material F is separated into aluminum sheets and rubber stoppers by a color sorter.

[0012] Furthermore, the treatment of the filtrate includes: adding 1%-5% by mass of an organic carboxylate, 0.05%-0.1% by mass of polyethylene glycol, and then adding 1%-5% by mass of sodium carbonate or sodium hydroxide to adjust the pH value to 7.0-7.5.

[0013] Optionally, the organic carboxylate includes one or more of sodium citrate or sodium tartrate.

[0014] Optionally, the degree of polymerization of the polyethylene glycol is one or more of 4000-10000.

[0015] Furthermore, the filter press is provided with a storage tank for containing the filtrate, and the storage tank is connected to the water spray pipe of the hydraulic crusher via a self-priming pump.

[0016] Furthermore, the primary air separation unit includes a frame, a feeding vibrating screen, an air duct fixed on the frame, a blower, and a primary cyclone dust collector; the feeding vibrating screen has a discharge port, and the air duct is arranged in the direction perpendicular to the ground from the discharge port; the lower part of the primary cyclone dust collector is provided with a first wind shield; the air duct includes a feed inlet, an air outlet, a baffle structure, a blower, and a second wind shield, the feed inlet being connected to the discharge port; the air outlet is located at the upper part of the air duct and is connected to the primary cyclone dust collector through a mesh pipe, the preliminarily separated electrolytic paper enters the primary cyclone dust collector from the air outlet and falls from the outlet of the first wind shield into the conveyor belt and is sent to the hydraulic crusher; the baffle structure is arranged inside the air duct; the blower is located at the lower part of the air duct and is connected to the blower through a pipe, the second wind shield is located at the bottom of the air duct, and the waste C falls from the outlet of the second wind shield into the conveyor belt and is sent to the secondary air separation unit.

[0017] Preferably, the baffle structure in the air duct is a multi-level baffle forming a serpentine structure. Each level of the baffle is composed of parallel baffles, and the center lines of two adjacent layers of baffles are set at 45° to each other. Two adjacent layers of baffles are connected by baffles on opposite sides of each layer, and the connection point between adjacent baffles on the same side in the air duct is located on a vertical line.

[0018] Preferably, the baffle structure is a serpentine structure composed of four levels of baffles.

[0019] Compared with existing technologies, the waste aluminum electrolytic capacitor recycling method of this invention uses a combination of physical and chemical treatment to harmlessly process waste aluminum electrolytic capacitors. First, the waste material (B) is sequentially processed by a crusher and a cyclone dust collector to recover crushed dust. Then, it is fed into a primary air separation unit, where it is separated into electrolytic paper and waste material (C). The electrolytic paper is then processed sequentially by a hydraulic crusher, a 6S shaking table, and a filter press to obtain electrolytic paper filter cake and filtrate. The filtrate is chemically treated for recycling. Waste material (C) is then separated into aluminum foil, guide pins, aluminum sheets, and rubber stoppers. This waste aluminum electrolytic capacitor recycling method of the present invention has low cost, requires no complex equipment, and uses a combination of physical and chemical treatment to separate waste aluminum electrolytic capacitors into electrolytic paper, aluminum foil, aluminum sheets, guide pins, and rubber stoppers, achieving excellent separation and recycling effects. Furthermore, the filtrate can be effectively recycled, resulting in significant economic and social benefits. Attached Figure Description

[0020] Figure 1 This is a flowchart of a waste aluminum electrolytic capacitor recycling method in an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the first-stage air separation unit in an embodiment of the present invention.

[0022] Figure 3 This is a partial schematic diagram of the first-stage air separation unit in an embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It should be understood that terms such as "upper," "lower," "left," "right," "top," "bottom," "inner," and "outer," indicating orientation or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms describing positional relationships in the drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] like Figure 1 , Figure 2 The figure shown is an embodiment of the waste aluminum electrolytic capacitor recycling method of the present invention.

[0025] like Figure 1 As shown, the waste aluminum electrolytic capacitor recycling method of the present invention includes the following steps:

[0026] First, waste aluminum electrolytic capacitors are crushed by a crusher to obtain waste material A. The crushed and separated waste material A is transported by a negative pressure fan through a duct to the cyclone dust collector at the rear of the crusher. The upper air outlet of the cyclone dust collector is connected to a pulse dust collector to recover crushed dust. The waste material B at the lower outlet is sent to the first-stage air separation unit via a conveyor belt.

[0027] Secondly, waste B is separated into electrolytic paper and waste C by a primary air separator. The electrolytic paper is fed into a hydraulic crusher for crushing via a conveyor belt. A 6S shaking table and a filter press connected by a diaphragm pump are installed below the discharge port of the hydraulic crusher. Waste D from the discharge port of the hydraulic crusher is washed by the 6S shaking table to obtain a solid-liquid mixture. The solid-liquid mixture is fed into the filter press by a diaphragm pump to obtain an electrolytic paper filter cake and a filter liquid containing electrolyte. The filter liquid is then chemically treated.

[0028] Next, waste C is separated into aluminum foil and waste E by a secondary air separation unit;

[0029] Then, waste E is separated into guide needles and waste F by a magnetic separator;

[0030] Finally, waste F is separated into aluminum sheets and rubber stoppers by a color sorter.

[0031] In the above steps, organic carboxylates and polyethylene glycol can be added when treating the filtrate, followed by the addition of sodium carbonate or sodium hydroxide to adjust the pH. Multiple experimental tests have shown that adding 1%-5% organic carboxylates, 0.05%-0.1% polyethylene glycol, and 1%-5% sodium carbonate or sodium hydroxide can adjust the pH of the treated filtrate to 7.0-7.5.

[0032] In embodiments of the present invention, the organic carboxylate may include one or more of sodium citrate or sodium tartrate, and the degree of polymerization of polyethylene glycol may be one or more of 4000-10000.

[0033] The equipment used in the waste aluminum electrolytic capacitor recycling method of this invention is simple. The primary air separation unit in this invention plays a significant role in the subsequent separation and recycling. For example... Figure 2 As shown, the primary air separation unit includes a frame 10, a feeding vibrating screen 20, an air duct 30 fixed to the frame 10, a blower 40, and a primary cyclone dust collector 50. The feeding vibrating screen 20 has a discharge port, and the air duct 30 is positioned vertically from the discharge port to the ground. The primary cyclone dust collector 50 has a first windbreak 51 at its lower part. Figure 2 As shown, the air duct 30 includes a feed inlet 31, an air outlet 32, a baffle structure 33, a blower 34, and a second windbreak 35. The feed inlet 31 is connected to the discharge port. The air outlet 32 ​​is located at the upper part of the air duct 30 and is connected to the primary cyclone dust collector 50 through a mesh pipe. The electrolytic paper, after preliminary separation, enters the primary cyclone dust collector 50 from the air outlet 32 ​​and falls from the outlet of the first windbreak 51 into the conveyor belt and is sent to the hydraulic crusher. The baffle structure 33 is located inside the air duct 30. The blower 34 is located at the lower part of the air duct 30 and is connected to the blower 40 through a pipe. The second windbreak 35 is located at the bottom of the air duct 30. Waste C falls from the outlet of the second windbreak 35 into the conveyor belt and is sent to the secondary air separator.

[0034] like Figure 3As shown, in this embodiment of the invention, the baffle structure 33 in the air duct 30 is a multi-level baffle that forms a serpentine structure. Each level of baffle is composed of mutually parallel baffle plates 331. The center lines of two adjacent layers of baffles are set at 45° to each other. Two adjacent layers of baffles are connected by baffle plates 331 on opposite sides of each layer, and the connection point between adjacent baffles on the same side in the air duct 30 is located on a vertical line. In actual use, waste material B enters the feed inlet 31 of the air duct 30 through the discharge port of the feeding vibrating screen 20, and then enters the baffle structure 33 of the air duct 30 for primary sorting. Since the lower part of the serpentine air duct 30 is connected to the blower 40, air flows from bottom to top through the serpentine air duct 30, performing double sorting on the waste material fed in from the top. At this time, the crushed electrolytic paper is separated from the air outlet 32 ​​at the top of the air duct 30 and falls through the primary cyclone dust collector 50, exiting from the outlet of the first windproof device 51 at the bottom of the primary cyclone dust collector 50 and falling into the conveyor belt to be sent to the hydraulic crusher. Secondly, since the bottom of the serpentine air duct 30 is equipped with a second windproof device 35, the waste material C separated from the electrolytic paper is exited from the outlet of the second windproof device 35 and falls into the conveyor belt to be sent to the secondary air separator. In one embodiment, the serpentine duct 30 is 60 cm wide and 240 cm high, and can be configured as a serpentine structure consisting of four levels of baffles. In practical applications, different substances can be separated by adjusting the airflow velocity, specific gravity, etc.

[0035] Furthermore, in the above embodiments, the filter press may also be equipped with a storage tank for containing the filtrate. The storage tank is connected to the water spray pipe of the hydraulic crusher via a self-priming pump. After the filtrate undergoes the aforementioned chemical treatment, it can be recycled and periodically tested with a density meter. For example, in one embodiment, when the density of the filtrate reaches or approaches a set value, it can be completely extracted and stored as a basic additive for the separation of alloys such as copper and tin.

[0036] Furthermore, it is understood that the recycling devices used in the waste aluminum electrolytic capacitor recycling method of the present invention, such as crushers, cyclone dust collectors, primary air separation units, hydraulic crushers, and secondary air separation units, are installed sequentially according to the process, and automatic conveying mechanisms such as conveyor belts are arranged between them.

[0037] The waste aluminum electrolytic capacitor recycling method of the present invention adopts a combination of physical and chemical treatment to harmlessly treat waste aluminum electrolytic capacitors. This recycling method has low cost, does not require complex equipment, and can separate waste aluminum electrolytic capacitors into electrolytic paper, aluminum foil, aluminum sheets, guide needles and rubber stoppers by using a combination of physical and chemical treatment methods. It has a better separation and recycling effect, and can also effectively recycle the filtrate, which has very good economic and social benefits.

[0038] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for recycling waste aluminum electrolytic capacitors, characterized in that, Includes the following steps: Waste aluminum electrolytic capacitors are crushed by a crusher to obtain waste material A. The crushed and separated waste material A is transported by a negative pressure fan through a duct to a cyclone dust collector at the rear end of the crusher. The upper outlet of the cyclone dust collector is connected to a pulse dust collector to recover crushed dust. The waste material B at the lower outlet is sent to the first-stage air separation unit via a conveyor belt. Waste B is separated into electrolytic paper and waste C by a primary air separator. The electrolytic paper is fed into a hydraulic crusher for crushing via a conveyor belt. A 6S shaking table and a filter press connected by a diaphragm pump are installed below the discharge port of the hydraulic crusher. Waste D from the discharge port of the hydraulic crusher is washed by the 6S shaking table to obtain a solid-liquid mixture. The solid-liquid mixture is fed into the filter press by the diaphragm pump to obtain an electrolytic paper filter cake and a filter liquid containing electrolyte. The filter liquid is then chemically treated. The waste material C is separated into aluminum foil and waste material E by a two-stage air separation unit; The waste material E is separated into guide needles and waste material F by a magnetic separator; The waste material F is separated into aluminum sheets and rubber stoppers by a color sorter.

2. The method for recycling waste aluminum electrolytic capacitors according to claim 1, characterized in that, The treatment of the filtrate includes: adding 1%-5% by mass of organic carboxylate, 0.05%-0.1% by mass of polyethylene glycol, and then adding 1%-5% by mass of sodium carbonate or sodium hydroxide to adjust the pH value to 7.0-7.

5.

3. The method for recycling waste aluminum electrolytic capacitors according to claim 2, characterized in that, The organic carboxylic acid salt includes one or more of sodium citrate or sodium tartrate.

4. The method for recycling waste aluminum electrolytic capacitors according to claim 2, characterized in that, The degree of polymerization of the polyethylene glycol is one or more of the range 4000-10000.

5. The method for recycling waste aluminum electrolytic capacitors according to claim 2, characterized in that, The filter press is equipped with a storage tank for containing the filtrate, and the storage tank is connected to the water spray pipe of the hydraulic crusher via a self-priming pump.

6. The method for recycling waste aluminum electrolytic capacitors according to claim 1, characterized in that, The primary air separation unit includes a frame, a feeding vibrating screen, an air duct fixed on the frame, a blower, and a primary cyclone dust collector. The feeding vibrating screen is provided with a discharge port, and the air duct is arranged in the direction perpendicular to the ground from the discharge port; the lower part of the primary cyclone dust collector is provided with a first wind shield; The air duct includes a feed inlet, an air outlet, a baffle structure, a blower, and a second wind shield. The feed inlet is connected to the discharge inlet. The air outlet is located at the upper part of the air duct and is connected to the primary cyclone dust collector via a mesh pipe. The electrolytic paper, after preliminary separation, enters the primary cyclone dust collector from the air outlet and falls from the outlet of the first wind shield into the conveyor belt and is fed into the hydraulic crusher. The baffle structure is located inside the air duct. The blower is located at the lower part of the air duct and is connected to the blower via a pipe. The second wind shield is located at the bottom of the air duct. The waste material C falls from the outlet of the second wind shield into the conveyor belt and is fed into the secondary air separator.

7. The method for recycling waste aluminum electrolytic capacitors according to claim 6, characterized in that, The baffle structure in the air duct is a multi-level baffle that forms a serpentine structure. Each level of the baffle is composed of parallel baffles. The center lines of two adjacent layers of baffles are set at 45° to each other. Two adjacent layers of baffles are connected by baffles on opposite sides of each layer, and the connection point between adjacent baffles on the same side in the air duct is located on a vertical line.

8. The method for recycling waste aluminum electrolytic capacitors according to claim 7, characterized in that, The baffle structure is a serpentine structure composed of four levels of baffles.

Images