Method for recovery of valuable metals from lithium ion batteries

Abstract

The application discloses a recycling method of valuable metals in lithium ion batteries, and relates to the technical field of battery recycling. The application adopts waste rubber particles as fuel and reducing agent, mixes the waste rubber particles with lithium ion battery electrode powder to granulate, and then carries out one-time and two-time roasting pyrolysis, so that the gas generated by the waste rubber particles has high calorific value and strong reducibility, the ternary lithium battery electrode powder can be reduced into soluble lithium oxide, and the lithium metal can be recycled through water immersion, the metal recovery rate is high, the energy consumption is low, the resource recycling rate can be improved by using the waste rubber particles, and the method is economical and environment-friendly.

Description

Technical Field

[0001] This application relates to the field of battery recycling, and more particularly to a method for recycling valuable metals from lithium-ion batteries. Background Technology

[0002] With the improvement and maturation of new energy vehicle technology in my country, the sales of lithium-ion battery-powered vehicles have continued to climb. However, due to the limited lifespan of power batteries, the number of scrapped power batteries has been increasing since 2020. Waste ternary lithium-ion batteries contain a large amount of valuable metals, typically including large amounts of Co, Ni, and Li, as well as small amounts of Cu, Al, and Fe. They may also contain organic compounds and plastics, making them highly valuable for recycling.

[0003] To date, many recycling technologies for spent ternary lithium-ion batteries based on high-temperature metallurgy and hydrometallurgical processes have been developed. However, high-temperature metallurgy processes face problems such as high material loss and high energy consumption. For the recovery of valuable metals from spent lithium-ion batteries, most methods employ conventional acid leaching in hydrometallurgy, which also suffers from long reaction times and low recovery rates. Summary of the Invention

[0004] This application provides a method for recycling valuable metals from lithium-ion batteries, using waste rubber particles as fuel and reducing agent to extract valuable metals from lithium-ion batteries in a low-energy-consumption and high-recovery-rate manner, which is economical and environmentally friendly.

[0005] To address the aforementioned technical problems, this application aims to provide a method for recovering valuable metals from lithium-ion batteries, comprising the following steps: mixing powder containing waste rubber particles, lithium-ion battery electrode powder, and a binder for granulation; spray drying followed by a first calcination pyrolysis reaction and a second calcination pyrolysis reaction; treating the waste residue after the calcination pyrolysis reaction with water to obtain a lithium-containing solution and residual residue; and recovering the residual residue to extract cobalt metal.

[0006] The reaction temperature of the primary calcination pyrolysis reaction is 200℃~500℃;

[0007] The reaction temperature of the secondary roasting pyrolysis reaction is 1100℃~1550℃.

[0008] In one embodiment, the mass ratio of the waste rubber particles to the lithium-ion battery electrode powder is (2-3):1.

[0009] In one embodiment, the powder also includes waste wood chips.

[0010] In one embodiment, the mass ratio of the waste wood chips to the lithium-ion battery electrode powder is (0.5-2):1.

[0011] Adding waste wood chips during the granulation process increases the binding properties of the granules, making their structure more stable. Because waste wood chips are small and have a low ignition point, they are more easily ignited during subsequent pyrolysis. The combustion of wood chips raises the reaction temperature to the initial temperature of the pyrolysis reaction. During combustion, waste wood chips are converted into C or CO, exhibiting a certain reducing effect. Simultaneously, the pyrolysis combustion process increases porosity, facilitating the contact and reaction of the reducing gases produced by pyrolysis with the electrode powder, thus improving reduction efficiency. However, excessive addition of waste wood chips can negatively impact reduction efficiency and increase pollutants. Limiting the amount of waste wood chips added ensures effective reduction while reducing pollution.

[0012] In one embodiment, the adhesive includes at least one of a compound adhesive, epoxy resin, phenolic resin, silicate, and phosphate, wherein the compound adhesive is glucose and citric acid in a mass ratio of (1-2):1.

[0013] In one embodiment, the adhesive is prepared by mixing glucose and citric acid thoroughly and heating to 40°C to 50°C to obtain the adhesive.

[0014] When glucose and citric acid are mixed and heated, they have a certain viscosity, which can be used for granulation of materials. This facilitates the thorough mixing of waste rubber granules and electrode powder, improving the pyrolysis effect. At the same time, since glucose is a polyhydroxy aldehyde containing a -CHO group, it has a certain reducing property. This property can assist the reducing gas generated by the waste rubber granules in the simultaneous reduction of the electrode powder. In addition, glucose is also flammable, providing the calorific value required for reduction, thus improving the overall reduction efficiency.

[0015] In one embodiment, the mass ratio of the powder to the binder is (2-4):1.

[0016] In one embodiment, the waste rubber particles have a particle size of 0.2 mm to 0.5 mm, and the lithium-ion battery electrode powder has a particle size of 0.2 mm to 0.5 mm.

[0017] The smaller the particle size of waste rubber granules and lithium-ion battery electrode powder, the better the final reduction effect and the higher the metal recovery rate, but the smaller the particle size, the higher the relative crushing cost.

[0018] In one embodiment, the waste rubber particles are derived from waste tires, waste belts, waste rubber hoses, or waste composite insulators.

[0019] Tire rubber is typically composed of natural rubber (NR), styrene-butadiene rubber (SBR), polybutadiene or butyl rubber, and small amounts of organic and inorganic additives. Since waste tire rubber is mainly composed of long-chain hydrocarbons, valuable hydrocarbons can be recovered from waste tires as energy and chemical raw materials if the tires are processed. The main gaseous components of tire pyrolysis are hydrogen (H2), methane (CH4), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), and butane (C4H4). 10 The primary degradation products of tire rubber during pyrolysis include high concentrations of olefins and dienes, particularly butadiene. Secondary reactions of the pyrolysis gases in the reactor's hot zone also lead to the formation of light hydrocarbons from the oil vapor produced during pyrolysis. These gases have a high calorific value, ranging from 20 MJ to 65 MJ / m³, which is sufficient for the reduction reaction. When waste tires are used as fuel and reducing agent, the pyrolysis temperature is relatively low, and the resulting gases have a high calorific value, which promotes the reduction reaction. The following reactions may occur:

[0020] 2LiCoO2+C==Li2CO3+CoO+Co;

[0021] 2LiCoO2+CO==Li2CO3+2CoO;

[0022] 2LiCoO2+CH4==L i2O+CO+2Co+2H2O;

[0023] 4LiCoO2+C2H4==2L i2CO3+4Co+2H2O;

[0024] 2LiCoO2+H2==L i2O+2CoO+H2O;

[0025] Subsequently, during a further high-temperature pyrolysis process, lithium carbonate is decomposed into water-soluble lithium oxide and carbon dioxide. The lithium metal is then recovered through water leaching, and the cobalt-containing residue is further recycled.

[0026] In one embodiment, the waste rubber granules are prepared by: separating the steel wires inside the waste tires using mechanical equipment, subjecting the waste tire rubber to a low temperature treatment of -120℃ to -70℃, and then crushing and screening them.

[0027] The lithium-ion battery electrode powder is prepared by subjecting the lithium-ion battery to low-temperature treatment at -120℃ to -70℃, followed by crushing and screening.

[0028] Liquid nitrogen can be used to treat waste tires and batteries at low temperatures, allowing for vitrification at temperatures of -70 to -120°C. When the rubber in waste tires is cooled to a certain temperature, it loses its elasticity, hardens, and becomes brittle, which is conducive to mechanical crushing. Deep cooling of batteries can freeze the electrolyte, which is beneficial for the safe breakage of the batteries.

[0029] In one embodiment, the lithium-ion battery electrode powder is a ternary lithium-ion battery positive electrode powder.

[0030] In one embodiment, the calcination pyrolysis reaction time is 30 min to 60 min.

[0031] In one embodiment, the secondary calcination pyrolysis reaction time is 60 min to 90 min.

[0032] In one embodiment, the specific steps for extracting lithium metal from the waste residue by water leaching are as follows: the waste residue and water are mixed at a solid-liquid ratio of 3:1, stirred and reacted for 30-60 minutes, and filtered to obtain a lithium-containing solution and the remaining residue.

[0033] In one embodiment, the specific steps for recycling the remaining residue to extract cobalt metal are as follows: mixing the residue with a leachate, wherein the leachate comprises 300 g / L sulfuric acid and hydrogen peroxide in a volume ratio of (3-6):1.

[0034] In one embodiment, the spray drying temperature is 80-200°C and the time is 5-30 seconds.

[0035] Compared with the prior art, this application has the following beneficial effects:

[0036] 1. This application utilizes the high calorific value of the gas generated by the pyrolysis of waste rubber particles. During the tire heating process, various hydrocarbons (gas), pyrolysis oil (liquid), and carbon black (solid) are generated, forming a solid-liquid-gas three-phase reaction. The calorific value is higher and the reduction reaction is more thorough. It can reduce ternary lithium battery electrode powder to Co3O2, CoO, Li2CO3, Co, Li2O and other components in a short time. In the further roasting and pyrolysis process, lithium carbonate is decomposed into lithium oxide. Lithium metal can be recovered by water leaching. The metal recovery rate is high and the energy consumption is low.

[0037] 2. This application uses waste rubber pellets as fuel and reducing agent, which is beneficial to the recycling and treatment of waste rubber pellets, improves the recycling efficiency of waste resources, reduces the cost of lithium-ion battery metal extraction, and at the same time reduces the environmental burden caused by waste rubber, thus having the advantages of being economical and environmentally friendly. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the steps in a method for recovering valuable metals from lithium-ion batteries according to this application.

[0039] Figure 2 The XRD results are those of the untreated ternary lithium-ion battery cathode powder in step (2) and the waste residue after the first calcination pyrolysis reaction in step (5) of this application. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0041] Example 1

[0042] A method for recovering valuable metals from lithium-ion batteries, such as... Figure 1 As shown, it includes the following steps:

[0043] (1) The steel wire inside the tire bead is completely separated by a mechanical cutting and drawing machine. The steel wire can be recycled. Liquid nitrogen is used to treat the waste tire rubber and the charged battery at low temperature. Glass conversion is carried out at a temperature of -70℃. The waste tire rubber will lose its elasticity and become hard and brittle after the temperature drops to a certain level. The waste tire rubber is crushed into granules and powder by a shredder. The waste tire rubber granules are washed with 60g / L sulfuric acid to remove aluminum. The charged battery is cryogenically cooled to freeze the electrolyte, which is beneficial to the safe crushing of the battery. Waste tire rubber granules with a particle size of 0.2mm and ternary lithium (LiCoO2) ion battery positive electrode powder are screened out.

[0044] (2) Glucose and citric acid are thoroughly mixed at a mass ratio of 2:1, and then heated to 45°C to prepare a biomass binder;

[0045] (3) Waste wood chips, waste tire rubber granules and ternary lithium-ion battery positive electrode powder are mixed in a mass ratio of 1:2:1 to form powder, and then the powder and biomass binder are granulated in a mass ratio of 3:1.

[0046] (4) The granulated material is spray-dried by passing it through an atomizer using a high-pressure pump at a temperature of 100°C for 15 seconds. The material is atomized into mist particles that come into direct contact with hot air for heat exchange, and drying is completed in a short time.

[0047] (5) After drying, the material undergoes a first roasting pyrolysis reaction in the absence of air. The reaction temperature is 220℃ and the reaction time is 60min. During this process, the waste tire rubber components can be effectively decomposed and reacted with the battery to generate components such as Co3O2, CoO, Li2CO3, Co, and Li2O. Then, a second roasting pyrolysis reaction is carried out in the absence of air. The reaction temperature is 1280℃ and the reaction time is 60min. At this temperature, lithium carbonate can be decomposed into waste residue whose main components are soluble lithium oxide and carbon dioxide.

[0048] (6) Valuable metals can be recovered from the calcined residue. The residue can be leached in water to generate a soluble lithium solution from Li2O. The solid-liquid ratio is 3:1 (g / ml), the stirring speed is 200 rpm, and the reaction time is 60 min. The remaining Co-containing residue can be recycled to prepare cobalt salt. The residue is soaked for 180 min by mixing 300 g / L sulfuric acid and hydrogen peroxide at a volume ratio of 4:1.

[0049] Example 2

[0050] A method for recovering valuable metals from lithium-ion batteries, such as... Figure 1 As shown, it includes the following steps:

[0051] (1) The steel wire inside the tire bead is completely separated by a mechanical cutting and drawing machine. The steel wire can be recycled. Liquid nitrogen is used to treat the waste tire rubber and the charged battery at low temperature. Glass conversion is carried out at a temperature of -80℃. The waste tire rubber will lose its elasticity and become hard and brittle after the temperature drops to a certain level. The waste tire rubber is crushed into granules and powder by a shredder. The waste tire rubber granules are cleaned with 60g / L sulfuric acid to remove aluminum. The charged battery is cryogenically cooled to freeze the electrolyte, which is beneficial to the safe crushing of the battery. Waste tire rubber granules with a particle size of 0.5mm and ternary lithium-ion battery positive electrode powder are screened out.

[0052] (2) Glucose and citric acid are thoroughly mixed at a mass ratio of 2:1, and then heated to 45°C to prepare a biomass binder;

[0053] (3) Waste wood chips, waste tire rubber granules and ternary lithium-ion battery positive electrode powder are mixed in a mass ratio of 1:2:1 to form powder, and then the powder and biomass binder are granulated in a mass ratio of 3:1.

[0054] (4) The granulated material is spray-dried by a high-pressure pump through an atomizer at a temperature of 80°C for 30 seconds. The material is atomized into mist particles and comes into direct contact with hot air for heat exchange, thus completing the drying process in a short time.

[0055] (5) After drying, the material undergoes a first roasting pyrolysis reaction in the absence of air. The reaction temperature is 420℃ and the reaction time is 30min. During this process, the waste tire rubber components can be effectively decomposed and reacted with the battery to generate components such as Co3O2, CoO, Li2CO3, Co, and Li2O. Then, a second roasting pyrolysis reaction is carried out in the absence of air. The reaction temperature is 1480℃ and the reaction time is 80min. At this temperature, lithium carbonate can be decomposed into waste residue whose main components are soluble lithium oxide and carbon dioxide.

[0056] (6) Valuable metals can be recovered from the calcined residue. The residue can be leached with water to generate a soluble lithium solution from Li2O. The solid-liquid ratio is 3:1 (g / ml), the stirring speed is 200 rpm, and the reaction time is 60 min. The remaining Co-containing residue can be recycled to prepare cobalt salt. The residue is soaked for 180 min by mixing 300 g / L sulfuric acid and hydrogen peroxide at a volume ratio of 4:1.

[0057] Example 3

[0058] A method for recovering valuable metals from lithium-ion batteries, such as... Figure 1 As shown, it includes the following steps:

[0059] (1) The steel wire inside the tire bead is completely separated by a mechanical cutting and drawing machine. The steel wire can be recycled. Liquid nitrogen is used to treat the waste tire rubber and the charged battery at low temperature. Glass conversion is carried out at a temperature of -120℃. The waste tire rubber will lose its elasticity and become hard and brittle after the temperature drops to a certain level. The waste tire rubber is crushed into granules and powder by a shredder. The waste tire rubber granules are cleaned with 60g / L sulfuric acid to remove aluminum. The charged battery is cryogenically cooled to freeze the electrolyte, which is beneficial to the safe crushing of the battery. Waste tire rubber granules with a particle size of 0.2mm and ternary lithium-ion battery positive electrode powder are screened out.

[0060] (2) Glucose and citric acid are thoroughly mixed at a mass ratio of 1:1, and then heated to 45°C to prepare a biomass binder;

[0061] (3) Waste wood chips, waste tire rubber granules and ternary lithium-ion battery positive electrode powder are mixed in a mass ratio of 1:3:1 to form powder, and then the powder and biomass binder are granulated in a mass ratio of 3:1.

[0062] (4) The granulated material is spray-dried by a high-pressure pump through an atomizer at a temperature of 200°C for 5 seconds. The material is atomized into mist particles and comes into direct contact with hot air for heat exchange, thus completing the drying process in a short time.

[0063] (5) After drying, the material undergoes a first roasting pyrolysis reaction in the absence of air. The reaction temperature is 420℃ and the reaction time is 30min. During this process, the waste tire rubber components can be effectively decomposed and reacted with the battery to generate components such as Co3O2, CoO, Li2CO3, Co, and Li2O. Then, a second roasting pyrolysis reaction is carried out in the absence of air. The reaction temperature is 1480℃ and the reaction time is 90min. At this temperature, lithium carbonate can be decomposed into waste residue whose main components are soluble lithium oxide and carbon dioxide.

[0064] (6) Valuable metals can be recovered from the calcined residue. The residue can be leached with water to generate a soluble lithium solution from Li2O. The solid-liquid ratio is 3:1 (g / ml), the stirring speed is 200 rpm, and the reaction time is 60 min. The remaining Co-containing residue can be recycled to prepare cobalt salt. The residue is soaked for 180 min by mixing 300 g / L sulfuric acid and hydrogen peroxide at a volume ratio of 4:1.

[0065] Example 4

[0066] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (2), the biomass binder is replaced by epoxy resin.

[0067] Example 5

[0068] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (3), the amount of waste wood chips added is 0.

[0069] Example 6

[0070] A method for recycling valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (3), the mass ratio of waste wood chips, waste tire rubber particles and ternary lithium-ion battery positive electrode powder is 0.5:2:1.

[0071] Example 7

[0072] A method for recycling valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (3), the mass ratio of waste wood chips, waste tire rubber particles and ternary lithium-ion battery positive electrode powder is 2:2:1.

[0073] Example 8

[0074] A method for recycling valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (3), waste wood chips, waste tire rubber particles and ternary lithium-ion battery positive electrode powder are mixed into powder at a mass ratio of 1:1:1.

[0075] Example 9

[0076] A method for recycling valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (2), the particle size of waste tire rubber particles and ternary lithium (LiCoO2) battery positive electrode powder is 0.8 mm.

[0077] Example 10

[0078] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (5), the pyrolysis temperature for the first roasting is 500°C.

[0079] Example 11

[0080] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (5), the pyrolysis temperature for the first roasting is 200°C.

[0081] Example 12

[0082] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (5), the secondary roasting pyrolysis temperature is 1100℃.

[0083] Example 13

[0084] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (5), the secondary roasting pyrolysis temperature is 1550℃.

[0085] Comparative Example 1

[0086] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (5), the dried material is subjected to a calcination pyrolysis reaction at a temperature of 220°C for a time of 60 min; in step (6), the waste residue after the calcination pyrolysis is subjected to water leaching to prepare a soluble lithium solution, and the remaining residue is recycled to prepare cobalt salt.

[0087] Comparative Example 2

[0088] A method for recovering valuable metals from lithium-ion batteries, wherein each step and the reagents and process parameters used in each step are the same as in Example 1, except that in step (5), the dried material is directly subjected to calcination pyrolysis reaction at a reaction temperature of 1280℃ and a reaction time of 60min; in step (6), the waste residue after secondary calcination pyrolysis is subjected to water leaching to prepare a soluble lithium solution, and the remaining residue is recycled to prepare cobalt salt.

[0089] Comparative Example 3

[0090] A method for recovering valuable metals from lithium-ion batteries includes the following steps:

[0091] (1) The steel wire inside the tire bead is completely separated by a mechanical cutting and drawing machine. The steel wire can be recycled. Liquid nitrogen is used to treat the waste tire rubber and the charged battery at low temperature. Glass conversion is carried out at a temperature of -70℃. The waste tire rubber will lose its elasticity and become hard and brittle after the temperature drops to a certain level. The waste tire rubber is crushed into granules and powder by a shredder. The waste tire rubber granules are cleaned with 60g / L sulfuric acid to remove aluminum. The charged battery is cryogenically cooled to freeze the electrolyte, which is beneficial to the safe crushing of the battery. Waste tire rubber granules with a particle size of 0.2mm and ternary lithium-ion battery positive electrode powder are screened out.

[0092] (2) Waste wood chips, waste tire rubber granules and ternary lithium-ion battery positive electrode powder are mixed into powder at a mass ratio of 3:1;

[0093] (3) The powder is subjected to a first roasting pyrolysis reaction in the absence of air. The reaction temperature is 220℃ and the reaction time is 60min. During this process, the waste tire rubber component can be effectively decomposed and reacted with the battery to generate components such as Co3O2, CoO, Li2CO3, Co, and Li2O. Then, a second roasting pyrolysis reaction is carried out in the absence of air. The reaction temperature is 1280℃ and the reaction time is 60min. At this temperature, lithium carbonate can be decomposed into waste residue whose main components are soluble lithium oxide and carbon dioxide.

[0094] (6) Valuable metals can be recovered from the calcined residue. Water leaching of the residue can generate a soluble lithium solution from Li2O. The solid-liquid ratio is 3:1 (g / ml), and the stirring reaction time is 60 min. The remaining Co-containing residue can be recycled to prepare cobalt salt. The residue is soaked for 180 min by mixing 300 g / L sulfuric acid and hydrogen peroxide at a volume ratio of 4:1.

[0095] Performance testing

[0096] 1. Reduction effect: XRD analysis was performed on the untreated ternary lithium-ion battery cathode powder from step (2) of Example 1 and the waste residue after secondary calcination and pyrolysis reaction in step (5). The results are as follows: Figure 2 As shown, the untreated ternary lithium-ion battery cathode powder contains a large amount of LiCoO3 components, while the waste residue obtained after secondary roasting pyrolysis and high-temperature reduction mainly consists of Co3O2, CoO, Co, Li2O and other components, and does not contain LiCoO3 components. This indicates that the LiCoO3 components are transformed and decomposed by high-temperature reduction with waste tire rubber components during the two roasting pyrolysis processes.

[0097] 2. Metal recovery rate: The metal content of the lithium salt solution and cobalt salt solution obtained in step (6) of the examples and comparative examples was determined, and the calculated metal recovery rate is shown in Table 1.

[0098] Table 1 - Recovery rates of lithium and cobalt metals in the examples and comparative examples of this application.

[0099] Testing items Lithium metal recovery rate (%) Cobalt metal recovery rate (%) Example 1 91.5％ 94.2％ Example 2 91.8％ 94.5％ Example 3 92.2％ 94.9％ Example 4 88.6％ 92.2％ Example 5 88.6％ 92.2％ Example 6 91％ 93.3％ Example 7 91.8％ 94.9％ Example 8 90.8％ 93.2％ Example 9 89.8％ 92.5％ Example 10 91.8％ 94.9％ Example 11 89.1％ 91.3％ Example 12 92.2％ 94.9％ Example 13 88.6％ 92.2％ Comparative Example 1 83.6％ 85.2％ Comparative Example 2 81％ 83.1％ Comparative Example 3 84.8％ 86.9％

[0100] Comparing the performance test results of Example 1 and Comparative Examples 1-2 in Table 1, it can be seen that Comparative Example 1, which only performs one roasting step, and Comparative Example 2, which only performs two roasting steps, have insufficient calorific value required for the reduction reaction or uneven contact with the reducing gas, making it difficult for the reducing gas to completely reduce the ternary lithium battery electrode powder during the tire heating process, resulting in a significant reduction in the recovery rate of lithium metal and cobalt metal.

[0101] By comparing the performance test results of Examples 1 and 5 and Comparative Example 3 in Table 1, it can be seen that the present application granulates the lithium-ion battery electrode powder to increase the contact area between the electrode powder and the reducing gas. At the same time, the use of sawdust for ignition during the calcination process results in a lower ignition point, and the pores generated during the burning of sawdust facilitate the contact between the electrode powder and the reducing gas, thereby improving the reduction efficiency of lithium cobalt metal.

[0102] By comparing the performance test results of Examples 1 and 4 in Table 1, it can be seen that in the process of granulating lithium-ion battery electrode powder, this application uses glucose and citric acid to increase viscosity. At the same time, glucose itself has a certain reducing property, which can assist the reducing gas generated by waste rubber particles to reduce the electrode powder simultaneously. In addition, glucose is flammable and provides the calorific value required for the reduction reaction, thereby improving the overall reduction rate of lithium cobalt metal.

[0103] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application.

Claims

1. A method for recovery of valuable metals in a lithium ion battery, characterized by, The method comprises the following steps: mixing a powder containing waste rubber particles, lithium ion battery electrode powder and a binder to granulate, spray drying, sequentially performing a first calcination pyrolysis reaction and a second calcination pyrolysis reaction, and performing water immersion treatment on the waste residue after the calcination pyrolysis reaction to obtain a lithium-containing solution and residual residue, and performing recovery treatment on the residual residue to obtain cobalt metal; the powder further comprises waste wood chips; the binder comprises a compounded binder, the compounded binder is glucose and citric acid in a mass ratio of (1-2):1; and the preparation method of the compounded binder comprises the following steps: mixing the glucose and the citric acid, heating to 40-50 DEG C, and preparing the compounded binder. The reaction temperature of the first calcination pyrolysis reaction is 200-500 DEG C. The reaction temperature of the second calcination pyrolysis reaction is 1100-1550 DEG C.

2. The method of recovering valuable metals from a lithium ion battery according to claim 1, wherein The mass ratio of the waste rubber particles to the lithium ion battery electrode powder is (2-3):

1.

3. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The mass ratio of the waste wood chips to the lithium ion battery electrode powder is (0.5-2):

1.

4. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The mass ratio of the powder to the binder is (2-4):

1.

5. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The particle size of the waste rubber particles is 0.2-0.5 mm, and the particle size of the lithium ion battery electrode powder is 0.2-0.5 mm.

6. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The waste rubber particles are derived from waste tires, waste belts, waste rubber tubes or waste composite insulators.

7. The method of recovering valuable metals from a lithium ion battery according to claim 6, wherein The preparation method of the waste rubber particles comprises the following steps: separating the steel wires in the waste tires by mechanical equipment, performing low-temperature treatment on the waste tire rubber at-120 DEG C to-70 DEG C, and crushing and screening. The preparation method of the lithium ion battery electrode powder comprises the following steps: performing low-temperature treatment on the lithium ion battery at-120 DEG C to-70 DEG C, and crushing and screening.

8. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The lithium ion battery electrode powder is ternary lithium ion battery positive electrode sheet powder.

9. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The first calcination pyrolysis reaction time is 30-60 min, and the second calcination pyrolysis reaction time is 60-90 min.

10. The method of claim 1, wherein the lithium ion battery is a lithium ion battery for electric vehicles. The specific steps for extracting lithium metal by water immersion treatment on the waste residue are as follows: mixing the waste residue and water according to a solid-liquid ratio of 3:1, stirring and reacting for 30-60 min, and filtering to obtain a lithium-containing solution and residual residue.

11. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The specific steps for extracting cobalt metal by recovery treatment on the residual residue are as follows: mixing the residual residue and leaching liquid, and the leaching liquid comprises 300 g / L sulfuric acid and hydrogen peroxide in a volume ratio of (3-6):

1.

12. The method of recovering valuable metals from a lithium ion battery of claim 1, wherein, The temperature of the spray drying is 80-200 DEG C, and the time is 5-30 s.

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