Wet dissociation method for all components of waste lithium battery

Abstract

The invention discloses an all-component wet dissociation method for a waste lithium battery, which comprises the following steps of: cutting the waste lithium battery into 20-100mm flaky materials by adopting a shear type tearing machine under the condition of spraying a neutralizing solution, and then dispersing in a hydraulic-ultrasonic coupling field; finally, the plastic diaphragm, the heavy flaky component and the graphite powder are obtained through one-time separation according to the density and size difference. The method has the advantages of high safety, high resource recovery rate, simple operation, economy and environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of resource treatment of waste lithium - ion batteries, and particularly relates to a method for wet dissociation of all components of waste lithium batteries. Background Art

[0002] Currently, the dry crushing and sorting process is generally adopted in the field of waste lithium - battery recycling. Under nitrogen protection, the battery is crushed into millimeter - sized particles by a high - speed crusher. This method has multiple technical bottlenecks: First, the waste lithium battery is prone to thermal runaway during the crushing process, and the risk of combustion and explosion is significant. Second, the violent mechanical action causes the iron shell, copper / aluminum foil to be mixed with black powder (positive and negative electrode materials), resulting in a high content of Fe / Cu / Al impurities in the black powder, which is difficult to reduce to less than 1%, seriously restricting the subsequent purification efficiency of hydrometallurgy. Third, the electrolyte components (such as LiPF6) volatilize at high temperatures during crushing (>60°C), causing lithium - ion loss, and the released HF gas causes secondary pollution. In addition, the traditional process requires the configuration of multiple - stage air - flow sorting and screening equipment, with a long process and increased energy consumption costs.

[0003] In the prior art, methods such as "a method for crushing and screening waste lithium - battery electrode materials" disclosed in Patent CN202210048078.5 and "a method and device for charged crushing of lithium batteries" disclosed in Patent CN202310421420.6 reduce the content of metal impurities through multi - stage separation. However, their core defects are as follows: ① In the crushing stage, a hammer - type crusher is used, resulting in over - crushing of the material, and the copper / aluminum foil forms micron - sized fragments that are difficult to effectively separate by screening. ② To prevent combustion and explosion during the crushing process, nitrogen needs to be continuously introduced to maintain the oxygen concentration below the critical value of combustion and explosion, which greatly increases the equipment sealing cost and it is difficult to avoid the combustion reaction of carbonate caused by local high - temperature points. ③ In the sorting stage, it relies on long processes such as cyclone separation - magnetic separation - vibration screening (density difference), and the single - pass separation efficiency of the plastic separator and black powder is low. It needs to be repeatedly processed to meet the industrial - level recycling requirements, significantly extending the processing cycle. More seriously, the prior art lacks a cooperative mechanism for in - situ treatment of electrolytes, resulting in the emission of toxic organic substances (such as DEC, EMC) with the waste gas, and an additional tail - gas treatment unit needs to be configured, pushing up the comprehensive cost. Although some technical equipment (such as the "improved wet charged crusher for waste lithium batteries" disclosed in CN201921916160.5) proposes to solve the combustion and explosion problem through wet crushing, its essence is still complete crushing, breaking the battery into micron - sized particles, and there are still problems such as difficult separation and metal mixing. These problems jointly restrict the large - scale application of waste lithium - battery resource technology. It is very urgent to develop an economically feasible treatment technology for short - range and high - efficiency dissociation of all components of waste lithium batteries. Summary of the Invention

[0004] The object of the present invention is to provide a method for wet dissociation of all components of waste lithium batteries, which has high safety and resource recovery rate, and is simple in operation, economical, environmentally friendly.

[0005] The technical solution of the present invention is as follows:

[0006] A method for wet dissociation of all components of waste lithium batteries, comprising the following steps:

[0007] (1) Using a shear tearing machine to tear the waste lithium battery into sheet components with a size of 20 - 100 mm. During the tearing process, a neutralizing solution is synchronously sprayed into the tearing chamber of the shear tearing machine to keep the temperature in the chamber ≤ 40 °C. Among them, the neutralizing solution is a carbonate or phosphate buffer solution system with a pH of 6 - 8;

[0008] (2) Transferring the sheet components to a hydraulic - ultrasonic coupling reaction tank, applying a hydraulic disturbance of 200 - 500 rpm and an ultrasonic field of 10 - 30 kHz, and dispersing for 5 - 10 min to obtain dissociated materials;

[0009] (3) Pumping the dissociated materials into a sedimentation tank, wherein the flow rate of the upward water flow in the sedimentation tank is 0.5 - 2 m / s, and a sieve plate with a pore size of 0.5 - 2 cm is provided in the sedimentation tank;

[0010] (4) Classifying and recovering the materials in the sedimentation tank. Among them, the floating materials above the liquid level in the sedimentation tank are the plastic diaphragms in the waste lithium batteries, the sediment materials on the sieve plate are the heavy components in the waste lithium batteries, and the sediment materials at the bottom of the sedimentation tank are the graphite powder in the waste lithium batteries.

[0011] In each of the above steps, in step (1), the waste lithium battery is first torn into sheet components with a size of 20 - 100 mm in an environment of spraying a neutralizing solution. During the process, the residual electric energy is released by the tearing and chopping method, and the neutralizing solution is used to absorb the energy, avoiding combustion and explosion accidents caused by short - circuit discharge and the escape of electrolyte components. At the same time, setting the tearing size at 20 - 100 mm can prevent the mixing of metal components and graphite powder due to too small size of the sheet components in subsequent steps or insufficient dissociation of the battery due to too large size. In addition, the neutralizing solution can also react with the hydrolysis products of the electrolyte in the waste lithium battery during the subsequent electrolyte treatment process.

[0012] In each of the above steps, in step (2), the different components in the sheet components are fully dispersed by the action of hydraulic disturbance and ultrasonic field. Specifically, since the binder in the negative electrode sheet (graphite and copper foil sheet) is water - soluble, the binder dissolves in the water environment, and the graphite powder fully falls off with the assistance of hydraulic disturbance and ultrasonic field. LiPF6 in the electrolyte components can also hydrolyze in the mixed environment of the neutralizing solution and water, and its product HF reacts with the neutralizing solution, while organic substances such as carbonates are enriched in the water phase and avoid escape.

[0013] In the above steps, in step (3), the separation of the plastic diaphragm, heavy components, and graphite powder is achieved in one step by using density and size differences.

[0014] In some preferred embodiments, two layers of sieve plates are provided in the settling tank, and the pore size of the upper sieve plate is larger than that of the lower sieve plate. The above technical solution can effectively prevent the sieve plate from being blocked by piled materials.

[0015] In some preferred embodiments, the sieve plate is inclined in the settling tank.

[0016] In some preferred embodiments, the drop ratio of the sieve plate is 0.15 - 0.25.

[0017] In some preferred embodiments, the sieve plate is a vibrating sieve plate, and 1 - 5 Hz pulse vibration is implemented.

[0018] In some preferred embodiments, the rotational speed of the shear - type tearing machine is 20 - 100 rpm, and the blade gap of the shear - type tearing machine is 3 - 8 mm. In the above technical solution, by optimizing the matching of the blade gap and the rotational speed, over - fragmentation and mixing of components such as iron, copper, and aluminum foil sheets can be avoided.

[0019] In some preferred embodiments, the power ratio of the hydraulic disturbance to the ultrasonic field is 1:0.8 - 1.2.

[0020] In some preferred embodiments, step (3) and step (4) are carried out simultaneously. The above technical solution can prevent excessive piled materials on the sieve plate from affecting the screening effect. In other possible implementation manners, those skilled in the art can judge whether step (3) is completed and whether step (4) can be carried out according to the amount of piled materials on the sieve plate.

[0021] The present invention has at least the following beneficial effects:

[0022] (1) Improved safety: The shredded method of tearing is used to release residual electric energy and the neutralizing liquid is used to absorb energy. Nitrogen protection is not required during the dissociation process, the risk of combustion and explosion is zero, and the electrolyte volatilization rate is significantly reduced;

[0023] (2) Resource - based efficiency improvement: Lithium (LiPF6) in the electrolyte does not escape due to high temperature and can be effectively enriched and recovered; the size of the metal foil sheets is appropriate, and the impurity mixing rate in the black powder is less than 0.5%, which can improve the efficiency of the subsequent separation and recovery process;

[0024] (3) Process simplification: The sorting process is reduced from the traditional 3 - 5 levels to 1 level, and the processing cycle is shortened;

[0025] (4) This method is simple to operate, economical, environmentally friendly, easy to be applied on a large scale, and has broad industrial application potential. Description of the Drawings

[0026] Figure 1 It is the process flow diagram of the wet whole-group dissociation method for waste lithium batteries provided by the present invention;

[0027] Figure 2 It is the schematic diagram of the wet whole-group dissociation method for waste lithium batteries provided by the present invention. Specific embodiments

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention; the technical features designed in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be noted that all terms (including technical terms and scientific terms) used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the technical field to which the present invention belongs, and should not be construed as a limitation to the present invention; it should be further understood that the terms used in the present invention should be understood as having meanings consistent with their meanings in the context of this specification and the relevant fields, and should not be understood in an idealized or overly formal sense, unless clearly defined as such in the present invention.

[0030] In the following embodiments, the water used can be one or more of distilled water, purified water, and drinking water; unless otherwise specified, the detection methods in the following embodiments are all conventional detection methods; unless otherwise specified, the reagents in the following embodiments are all purchased from commercial channels.

[0031] The technical solutions of the present invention are further illustrated and described below through specific embodiments. However, the protection scope of the present invention is not limited thereto.

[0032] The present application has no special limitation on the feeding ratio of waste lithium batteries and neutralizing liquid. The temperature in the tearing cavity can be detected by conventional technical means such as infrared detectors and the spraying amount of the neutralizing liquid can be adjusted according to the actual situation. According to the tests of the applicant, the neutralizing liquid used in the following examples and comparative examples is sufficient to achieve a good cooling effect and fully react with HF generated after the hydrolysis of LiPF6 to prevent HF from escaping in the form of gas at a feeding ratio of 3:0.8 - 1.2 in terms of the mass ratio of waste lithium batteries to the neutralizing liquid. The following examples and comparative examples are all sprayed according to a mass ratio of 3:1 of waste lithium batteries to the neutralizing liquid. At the same time, the dissociation process is carried out in the collected neutralizing liquid; after the neutralizing liquid is purified (fluorine / phosphorus removal) and lithium is recovered, buffer substances are appropriately added and it can be recycled.

[0033] The equipment used in the present application can be obtained by those skilled in the art by combining or modifying existing equipment without special description and limitation. Among them, the settling tank is a hydraulic classification and settling device that drives the accumulated materials to move upward by the upward water flow in the opposite direction of the settling direction and then separates them by density. In the present application, a sieve plate is arranged in the settling tank. Those skilled in the art should be able to understand that the sieve plate matches the shape and size of the cross-section of the settling tank where the sieve plate is arranged. Otherwise, the materials will directly settle to the bottom of the tank without being sorted by the sieve plate, which violates the inventive concept of the present application.

[0034] The heavy components mentioned in the present application include the positive electrode sheet (including the positive electrode current collector such as aluminum foil, the positive electrode powder loaded on the current collector as the active material, and the water-insoluble binder that binds the positive electrode current collector and the positive electrode powder), the current collector of the negative electrode (such as copper foil), and iron sheets. In the present application, after the waste lithium batteries are dispersed in step (2), the heavy components are separated by density and size differences. Those skilled in the art can further recover and process the heavy components by common technical means in the art.

[0035] The drop ratio of the sieve plate mentioned in the present application refers to the ratio of the vertical drop of the sieve surface (i.e., the height difference between the feeding end and the discharging end of the sieve surface) to the horizontal length of the sieve surface.

[0036] Example 1

[0037] This example provides a wet full-component dissociation method for waste lithium batteries, referring to Figure 1 and Figure 2 , including the following steps:

[0038] (1) Use a shear tearing machine to tear the waste lithium batteries into sheet components of 20 mm, and synchronously spray the neutralizing liquid into the tearing cavity of the shear tearing machine during the tearing process to make the temperature in the cavity ≤ 40 °C;

[0039] Among them, the neutralizing solution used in this embodiment is a carbonate buffer solution (a composite solution of 10 wt% sodium carbonate and 1 wt% citric acid), the rotation speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0040] (2) Transfer the sheet-like components to a hydro-ultrasonic coupling reaction tank, and obtain dissociated materials after dispersing for 5 minutes;

[0041] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotation speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0042] (3) Pump the dissociated materials into a settling tank provided with double-layer inclined sieve plates. Among them, the head loss ratio of the settling tank is 0.15, the flow velocity of the upward flow of water is 0.5 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. The aperture of the upper sieve plate is 2.0 cm, the aperture of the lower sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 1 Hz and the amplitude is 3 mm.

[0043] (4) While performing step (3), classify and recover the materials in the settling tank;

[0044] Among them, scrape the floating materials above the liquid level of the settling tank and obtain a plastic diaphragm after drying. Filter the water from the settled materials 1 on the sieve plate and dry them to obtain sheet-like heavy components, and collect and dry the settled materials 2 at the bottom of the tank to obtain graphite powder.

[0045] In this embodiment, the recovery rate of the plastic diaphragm is 90.21%, and the recovery rate of the graphite powder is 93.12%.

[0046] Example 2

[0047] This embodiment provides a method for wet full-component dissociation of waste lithium batteries, referring to Figure 1 and Figure 2 , including the following steps:

[0048] (1) Use a shear tearing machine to tear the waste lithium battery into sheet-like components of 100 mm. During the tearing process, synchronously spray a neutralizing solution into the tearing chamber of the shear tearing machine so that the temperature in the chamber ≤ 40 °C;

[0049] Among them, the neutralizing solution used in this embodiment is a carbonate buffer solution (a composite solution of 10 wt% sodium carbonate and 1 wt% citric acid), the rotation speed of the shear tearing machine is 20 rpm, and the blade gap is 8 mm.

[0050] (2) Transfer the sheet-like components to a hydro-ultrasonic coupling reaction tank, and obtain dissociated materials after dispersing for 5 minutes;

[0051] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotational speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0052] (3) Pump the dissociated materials into a settling tank equipped with double-layer inclined sieve plates. Among them, the drop ratio of the settling tank is 0.15, the flow velocity of the upward flow is 0.5 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. The aperture of the upper sieve plate is 2.0 cm, the aperture of the lower sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 1 Hz and the amplitude is 3 mm.

[0053] (4) While performing step (3), classify and recover the materials in the settling tank;

[0054] Among them, scrape the floating materials above the liquid level of the settling tank and obtain a plastic diaphragm after drying. Filter and dry the settled materials 1 on the sieve plate to obtain flaky heavy components, and collect and dry the settled materials 2 at the bottom of the tank to obtain graphite powder.

[0055] In this embodiment, the recovery rate of the plastic diaphragm is 83.18%, and the recovery rate of graphite powder is 92.37%.

[0056] Example 3

[0057] This embodiment provides a wet whole-component dissociation method for waste lithium batteries. Refer to Figure 1 and Figure 2 , including the following steps:

[0058] (1) Use a shear tearing machine to tear the waste lithium battery into sheet components of 20 mm. During the tearing process, spray a neutralizing liquid into the tearing chamber of the shear tearing machine synchronously so that the temperature in the chamber ≤ 40 °C;

[0059] Among them, the neutralizing liquid used in this embodiment is a carbonate buffer solution (10 wt% sodium carbonate and 1 wt% citric acid composite solution). The rotational speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0060] (2) Transfer the sheet components to a hydraulic-ultrasonic coupling reaction tank and disperse for 5 min to obtain dissociated materials;

[0061] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotational speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 30 kHz, the power is 2.4 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:1.2.

[0062] (3) Pump the dissociated materials into a settling tank equipped with double-layer inclined sieve plates. Among them, the head difference ratio of the settling tank is 0.15, the flow velocity of the upward flow of water is 0.5 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. Among them, the aperture of the upper sieve plate is 2.0 cm, the aperture of the lower sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 1 Hz and the amplitude is 3 mm.

[0063] (4) While performing step (3), classify and recover the materials in the settling tank;

[0064] Among them, use a scraper to collect the floating materials above the liquid level of the settling tank, and obtain a plastic diaphragm after drying. Filter and dry the sediment 1 on the sieve plate to obtain a flaky heavy component, and collect and dry the sediment 2 at the bottom of the tank to obtain graphite powder.

[0065] In this embodiment, the recovery rate of the plastic diaphragm is 92.21%, and the recovery rate of graphite powder is 97.12%.

[0066] Example 4

[0067] This embodiment provides a method for wet full-component dissociation of waste lithium batteries. Refer to Figure 1 and Figure 2 , and includes the following steps:

[0068] (1) Use a shear tearing machine to tear the waste lithium battery into sheet components of 20 mm. During the tearing process, spray a neutralizing liquid into the tearing cavity of the shear tearing machine synchronously so that the temperature in the cavity ≤ 40°C;

[0069] Among them, the neutralizing liquid used in this embodiment is a carbonate buffer solution (a composite solution of 10 wt% sodium carbonate and 1 wt% citric acid). The rotation speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0070] (2) Transfer the sheet components to a hydraulic-ultrasonic coupling reaction tank, and obtain dissociated materials after dispersing for 5 minutes;

[0071] Among them, this embodiment uses an impeller to achieve hydraulic disturbance. The rotation speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0072] (3) Pump the dissociated materials into a settling tank equipped with double-layer inclined sieve plates. Among them, the head difference ratio of the settling tank is 0.25, the flow velocity of the upward flow of water is 0.5 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. Among them, the aperture of the upper sieve plate is 2.0 cm, the aperture of the lower sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 1 Hz and the amplitude is 3 mm.

[0073] (4) While performing step (3), the materials in the settling tank are classified and recovered;

[0074] Among them, the floating materials above the liquid level of the settling tank are collected by a scraper, dried to obtain a plastic diaphragm, the settled material 1 on the sieve plate is filtered and dried to obtain a sheet-like heavy component, and the settled material 2 at the bottom of the tank is collected and dried to obtain graphite powder.

[0075] In this embodiment, the recovery rate of the plastic diaphragm is 91.34%, and the recovery rate of graphite powder is 94.23%.

[0076] Example 5

[0077] This embodiment provides a wet whole-component dissociation method for waste lithium batteries. Referring to Figure 1 and Figure 2 , it includes the following steps:

[0078] (1) Use a shear tearing machine to tear the waste lithium battery into sheet-like components of 20 mm. During the tearing process, a neutralizing solution is synchronously sprayed into the tearing chamber of the shear tearing machine to make the temperature in the chamber ≤ 40°C;

[0079] Among them, the neutralizing solution used in this embodiment is a carbonate buffer solution (a composite solution of 10 wt% sodium carbonate and 1 wt% citric acid). The rotation speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0080] (2) Transfer the sheet-like components to a hydraulic-ultrasonic coupling reaction tank, and disperse for 5 minutes to obtain dissociated materials;

[0081] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotation speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0082] (3) Pump the dissociated materials into a settling tank equipped with a double-layer inclined sieve plate. Among them, the head difference ratio of the settling tank is 0.15, the flow velocity of the rising water flow is 0.5 m / s. The above sieve plate is a vibrating sieve plate made of 304 stainless steel. The aperture of the upper sieve plate is 2.0 cm, the aperture of the lower sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 5 Hz and the amplitude is 3 mm.

[0083] (4) While performing step (3), the materials in the settling tank are classified and recovered;

[0084] Among them, the floating materials above the liquid level of the settling tank are collected by a scraper, dried to obtain a plastic diaphragm, the settled material 1 on the sieve plate is filtered and dried to obtain a sheet-like heavy component, and the settled material 2 at the bottom of the tank is collected and dried to obtain graphite powder.

[0085] In this embodiment, the recovery rate of the plastic diaphragm is 94.32%, and the recovery rate of the graphite powder is 96.43%.

[0086] Example 6

[0087] This embodiment provides a method for wet whole-group dissociation of waste lithium batteries, referring to Figure 1 and Figure 2 , and includes the following steps:

[0088] (1) Use a shear tearing machine to tear the waste lithium battery into sheet components of 20 mm. During the tearing process, spray a neutralizing solution into the tearing chamber of the shear tearing machine synchronously to make the temperature in the chamber ≤ 40°C;

[0089] Among them, the neutralizing solution used in this embodiment is a carbonate buffer solution (a composite solution of 10 wt% sodium carbonate and 1 wt% citric acid). The rotation speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0090] (2) Transfer the sheet components to a hydraulic-ultrasonic coupling reaction tank and obtain dissociated materials after dissociation for 5 minutes;

[0091] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotation speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0092] (3) Pump the dissociated materials into a sedimentation tank equipped with double-layer inclined sieve plates. Among them, the drop ratio of the sedimentation tank is 0.15, the flow velocity of the upward flow of water is 2 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. The aperture of the upper sieve plate is 2.0 cm, the aperture of the lower sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 5 Hz and the amplitude is 3 mm.

[0093] (4) While performing step (3), classify and recover the materials in the sedimentation tank;

[0094] Among them, use a scraper to collect the floating materials above the liquid level of the sedimentation tank, dry them to obtain a plastic diaphragm, filter and dry the settled materials 1 on the sieve plate to obtain sheet-like heavy components, and collect and dry the settled materials 2 at the bottom of the tank to obtain graphite powder.

[0095] In this embodiment, the recovery rate of the plastic diaphragm is 95.21%, and the recovery rate of the graphite powder is 93.45%.

[0096] Example 7

[0097] This embodiment provides a method for wet whole-group dissociation of waste lithium batteries, referring to Figure 1 and Figure 2 , and includes the following steps:

[0098] (1) Use a shear tearing machine to tear the waste lithium battery into sheet components with a size of 20 mm. During the tearing process, spray neutralizing liquid into the tearing chamber of the shear tearing machine synchronously to keep the temperature in the chamber ≤ 40°C;

[0099] Among them, the neutralizing liquid used in this embodiment is a carbonate buffer solution (a composite solution of 10 wt% sodium carbonate and 1 wt% citric acid). The rotation speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0100] (2) Transfer the sheet components to a hydro - ultrasonic coupling reaction tank, and obtain dissociated materials after dispersing for 10 min;

[0101] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotation speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0102] (3) Pump the dissociated materials into a sedimentation tank equipped with double - layer inclined sieve plates. Among them, the drop ratio of the sedimentation tank is 0.15, the flow velocity of the upward flow of water is 0.5 m / s. The above - mentioned sieve plates are vibrating sieve plates made of 304 stainless steel. The aperture of the upper - layer sieve plate is 2.0 cm, the aperture of the lower - layer sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 1 Hz and the amplitude is 3 mm.

[0103] (4) While performing step (3), classify and recover the materials in the sedimentation tank;

[0104] Among them, use a scraper to collect the floating materials above the liquid level of the sedimentation tank, and obtain a plastic diaphragm after drying. Filter and dry the sediment 1 on the sieve plate to obtain sheet - shaped heavy components, and collect and dry the sediment 2 at the bottom of the tank to obtain graphite powder.

[0105] In this embodiment, the recovery rate of the plastic diaphragm is 92.72%, and the recovery rate of graphite powder is 95.33%.

[0106] Example 8

[0107] This embodiment provides a method for wet - type full - component dissociation of waste lithium batteries. Refer to Figure 1 and Figure 2 , including the following steps:

[0108] (1) Use a shear tearing machine to tear the waste lithium battery into sheet components with a size of 20 mm. During the tearing process, spray neutralizing liquid into the tearing chamber of the shear tearing machine synchronously to keep the temperature in the chamber ≤ 40°C;

[0109] Among them, the neutralizing solution used in this embodiment is phosphate buffer solution (0.5M Na2HPO4 + 0.2M citric acid + 0.1wt% polyacrylamide). The rotation speed of the shearing type tearing machine is 100rpm, and the blade gap is 3mm.

[0110] (2) Transfer the flaky components to a hydro - ultrasonic coupling reaction tank, and obtain dissociated materials after dispersing for 5 minutes;

[0111] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotation speed of the impeller is 300rpm, the power is 2kW, the frequency of the ultrasonic field is 20kHz, the power is 1.6kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0112] (3) Pump the dissociated materials into a sedimentation tank equipped with double - layer inclined sieve plates. Among them, the head - drop ratio of the sedimentation tank is 0.15, the flow velocity of the upward flow of water is 0.5m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. The aperture of the upper sieve plate is 2.0cm, the aperture of the lower sieve plate is 0.5cm, and the pulse vibration frequency of the vibrating sieve plate is 1Hz, and the amplitude is 3mm.

[0113] (4) While performing step (3), classify and recover the materials in the sedimentation tank;

[0114] Among them, the floating materials above the liquid surface of the sedimentation tank are collected by a scraper, and after drying, a plastic diaphragm is obtained. The sediment 1 on the sieve plate is filtered and dried to obtain flaky heavy components, and the sediment 2 at the bottom of the tank is collected and dried to obtain graphite powder.

[0115] In this embodiment, the recovery rate of the plastic diaphragm is 91.01%, and the recovery rate of graphite powder is 92.98%.

[0116] Comparative Example 1

[0117] The comparative example includes the following steps:

[0118] (1) Use a shearing type tearing machine to tear the waste lithium battery into flaky components with a size < 20mm. During the tearing process, a neutralizing solution is synchronously sprayed into the tearing chamber of the shearing type tearing machine to make the temperature in the chamber ≤ 40°C;

[0119] Among them, the neutralizing solution used in this embodiment is carbonate buffer solution (a composite solution of 10wt% sodium carbonate and 1wt% citric acid). The rotation speed of the shearing type tearing machine is 200rpm, and the blade gap is 2mm.

[0120] (2) Transfer the flaky components to a hydro - ultrasonic coupling reaction tank, and obtain dissociated materials after dispersing for 5 minutes;

[0121] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotational speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0122] (3) Pump the dissociated materials into a settling tank equipped with double-layer inclined sieve plates. Among them, the head difference ratio of the settling tank is 0.15, the flow velocity of the upward flow is 0.5 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. The aperture of the upper sieve plate is 2.0 cm, and the aperture of the lower sieve plate is 0.5 cm. The pulse vibration frequency of the vibrating sieve plate is 1 Hz, and the amplitude is 3 mm.

[0123] (4) While performing step (3), classify and recover the materials in the settling tank;

[0124] Among them, scrape the floating materials above the liquid surface of the settling tank and obtain a plastic diaphragm after drying. Filter the water from the sediment on the lower sieve plate and dry it to obtain flaky partial heavy components. Collect and dry the sediment at the bottom of the tank to obtain a mixed metal and graphite powder.

[0125] Filter the water from the sediment 1 on the sieve plate and dry it to obtain flaky heavy components. Collect and dry the sediment 2 at the bottom of the tank. The metal is seriously mixed in the obtained graphite powder, and the quality is poor.

[0126] Comparative Example 2

[0127] The comparative example includes the following steps:

[0128] (1) Use a shear tearing machine to tear the waste lithium battery into sheet components with a size > 100 mm. During the tearing process, synchronously spray a neutralizing liquid into the tearing chamber of the shear tearing machine so that the temperature in the chamber ≤ 40°C;

[0129] Among them, the neutralizing liquid used in this embodiment is a carbonate buffer solution (10 wt% sodium carbonate and 1 wt% citric acid composite solution). The rotational speed of the shear tearing machine is 10 rpm, and the blade gap is 10 mm.

[0130] (2) Transfer the sheet components to a hydraulic-ultrasonic coupling reaction tank and disperse for 5 minutes to obtain dissociated materials;

[0131] Among them, in this embodiment, an impeller is used to achieve hydraulic disturbance. The rotational speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0132] (3) Pump the dissociated material into a settling tank equipped with double-layer inclined sieve plates. Among them, the head difference ratio of the settling tank is 0.15, and the flow velocity of the upward flow of water is 0.5 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. Among them, the aperture of the upper sieve plate is 2.0 cm, and the aperture of the lower sieve plate is 0.5 cm. The pulse vibration frequency of the vibrating sieve plate is 1 Hz and the amplitude is 3 mm.

[0133] (4) While performing step (3), classify and recover the materials in the settling tank;

[0134] Among them, use a scraper to collect the floating materials above the liquid level of the settling tank, and obtain a small amount of plastic diaphragm after drying. Collect and dry the sediment 2 at the bottom of the tank to obtain a small amount of graphite powder. Filter and dry the sediment 1 on the sieve plate to obtain a heavy flaky component.

[0135] Due to the too large crushing size of the waste lithium battery, the dispersion in step (2) is incomplete. Most of the plastic diaphragm and graphite powder are mixed in the sediment 1, and the production of floating materials and sediment 2 is small.

[0136] Comparative Example 3

[0137] The comparative example includes the following steps:

[0138] (1) Use a shear tearing machine to tear the waste lithium battery into sheet components of 20 mm. During the tearing process, spray a neutralizing liquid into the tearing chamber of the shear tearing machine synchronously to make the temperature in the chamber ≤ 40 °C;

[0139] Among them, the neutralizing liquid used in this example is a carbonate buffer solution (10 wt% sodium carbonate and 1 wt% citric acid composite solution). The rotation speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0140] (2) Transfer the sheet components to a hydraulic-ultrasonic coupling reaction tank, and obtain dissociated materials after dispersing for 5 minutes;

[0141] Among them, this example uses an impeller to achieve hydraulic disturbance. The rotation speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 5 kHz, and the power is 0.4 kW. The power ratio of hydraulic disturbance to the ultrasonic field is lower than 1:0.2.

[0142] (3) Pump the dissociated material into a settling tank equipped with double-layer inclined sieve plates. Among them, the head difference ratio of the settling tank is 0.15, and the flow velocity of the upward flow of water is 0.5 m / s. The above sieve plates are vibrating sieve plates made of 304 stainless steel. Among them, the aperture of the upper sieve plate is 2.0 cm, and the aperture of the lower sieve plate is 0.5 cm. The pulse vibration frequency of the vibrating sieve plate is 1 Hz and the amplitude is 3 mm.

[0143] (4) While performing step (3), classify and recover the materials in the settling tank;

[0144] Among them, the floating materials above the liquid surface of the settling tank are collected by a scraper, dried to obtain a plastic diaphragm, the settled materials 1 on the sieve plate are dehydrated and dried to obtain sheet-like heavy components, and the settled materials 2 at the bottom of the tank are collected and dried to obtain graphite powder.

[0145] In this comparative example, the recovery rate of the plastic diaphragm is 88.12%, and the recovery rate of the graphite powder is 43.45%. This is because the power of the ultrasonic field in step (2) is weak, resulting in insufficient dispersion of the graphite powder and poor recovery effect.

[0146] Comparative Example 4

[0147] This comparative example includes the following steps:

[0148] (1) Use a shear tearing machine to tear the waste lithium battery into sheet-like components with a size of 20 mm. During the tearing process, a neutralizing solution is synchronously sprayed into the tearing chamber of the shear tearing machine to keep the temperature in the chamber ≤ 40°C;

[0149] Among them, the neutralizing solution used in this example is a carbonate buffer solution (a composite solution of 10 wt% sodium carbonate and 1 wt% citric acid), the rotation speed of the shear tearing machine is 100 rpm, and the blade gap is 3 mm.

[0150] (2) Transfer the sheet-like components to a hydro-ultrasonic coupling reaction tank, and disperse for 5 minutes to obtain dissociated materials;

[0151] Among them, in this example, an impeller is used to achieve hydraulic disturbance. The rotation speed of the impeller is 300 rpm, the power is 2 kW, the frequency of the ultrasonic field is 20 kHz, the power is 1.6 kW, and the power ratio of hydraulic disturbance to the ultrasonic field is 1:0.8.

[0152] (3) Pump the dissociated materials into a settling tank equipped with a double-layer inclined sieve plate. Among them, the head loss ratio of the settling tank is 0.15, the flow velocity of the upward flow of water is 0.5 m / s. The above sieve plate is a vibrating sieve plate made of 304 stainless steel. The aperture of the upper sieve plate is 2.0 cm, the aperture of the lower sieve plate is 0.5 cm, and the pulse vibration frequency of the vibrating sieve plate is 0 Hz and the amplitude is 3 mm.

[0153] (4) While performing step (3), the materials in the settling tank are classified and recovered;

[0154] Among them, the floating materials above the liquid surface of the settling tank are collected by a scraper, dried to obtain a plastic diaphragm, the settled materials 1 on the sieve plate are dehydrated and dried to obtain sheet-like heavy components, and the settled materials 2 at the bottom of the tank are collected and dried to obtain graphite powder.

[0155] The recovery rate of the plastic diaphragm is 89.86%, and the recovery rate of the graphite is 64.12%. This is because of the micro-vibration of the sieve plate, resulting in the accumulation of some settled materials and the decline of the separation effect.

[0156] In addition, those skilled in the art should understand that although there are many problems in the prior art, each embodiment or technical solution of the present invention can be improved in only one or several aspects, and it is not necessary to solve all the technical problems listed in the prior art or the background art at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be regarded as a limitation to that claim.

[0157] Although terms such as waste lithium iron phosphate black powder, acid leaching residue, alkaline metal compounds, salinization conversion, water washing and filtration are used more frequently herein, the possibility of using other terms is not excluded. The use of these terms is only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention; the terms "first", "second", etc. (if any) in the specification, claims and the above-mentioned drawings of the embodiments of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wet dissociation method for all components of waste lithium batteries, characterized in that, It includes the following steps: (1) Use a shearing tear machine to tear the waste lithium battery into sheet components with a size of 20 - 100 mm. During the tearing process, spray a neutralizing liquid into the tearing chamber of the shearing tear machine synchronously to keep the temperature in the chamber ≤ 40°C. Among them, the neutralizing liquid is a carbonate or phosphate buffer solution system with a pH of 6 - 8; (2) Transfer the sheet components to a hydraulic - ultrasonic coupling reaction tank, apply a hydraulic disturbance of 200 - 500 rpm and an ultrasonic field of 10 - 30 kHz, and disperse for 5 - 10 minutes to obtain dissociated materials; (3) Pump the dissociated materials into a sedimentation tank. Among them, the flow rate of the upward water flow in the sedimentation tank is 0.5 - 2 m / s, and a sieve plate with a pore size of 0.5 - 2 cm is set in the sedimentation tank; (4) Classify and recover the materials in the sedimentation tank. Among them, the floating materials above the liquid level in the sedimentation tank are the plastic diaphragms in the waste lithium battery, the sediment materials on the sieve plate are the heavy components in the waste lithium battery, and the sediment materials at the bottom of the sedimentation tank are the graphite powder in the waste lithium battery.

2. The wet dissociation method for all components of waste lithium batteries according to claim 1, wherein There are two layers of the sieve plates arranged up and down in the sedimentation tank, and the pore size of the upper sieve plate is larger than that of the lower sieve plate.

3. The wet dissociation method for all components of waste lithium batteries according to claim 2, wherein, The sieve plate is inclined in the sedimentation tank.

4. The wet dissociation method for all components of waste lithium batteries according to claim 3, wherein, The drop ratio of the sieve plate is 0.15 - 0.

25.

5. The wet dissociation method for all components of waste lithium batteries according to claim 2, wherein, The sieve plate is a vibrating sieve plate, and a pulse vibration of 1 - 5 Hz is implemented.

6. The wet dissociation method for all components of waste lithium batteries according to claim 1, characterized in that The rotation speed of the shearing tear machine is 20 - 100 rpm, and the blade gap of the shearing tear machine is 3 - 8 mm.

7. The wet dissociation method for all components of waste lithium batteries according to claim 1, characterized in that, The power ratio of the hydraulic disturbance and the ultrasonic field is 1:0.8 - 1.

2.

8. The wet dissociation method for all components of waste lithium batteries according to claim 1, characterized in that, The step (3) and the step (4) are carried out simultaneously.

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