Co-processing method of waste lithium battery pole powder and vulcanized slag waste

Abstract

The application belongs to the technical field of lithium battery recycling, and particularly relates to a co-treatment method for waste lithium battery pole powder and sulfurized slag waste, which comprises the following steps: S1, obtaining lithium battery pole powder and sulfurized slag waste, wherein the lithium battery pole powder comprises lithium battery positive pole powder; S2, slurry mixing the lithium battery pole powder and the sulfurized slag waste according to a mass ratio of (2-6):1 to obtain first slurry; S3, high-temperature leaching of the first slurry by using leaching acid, and then solid-liquid separation to obtain leaching liquid and leaching residue, and recycling the leaching liquid; by mixing the sulfurized slag and the lithium battery waste, the application does not need to additionally add oxidizing agent or reducing agent auxiliary materials in the battery pole powder leaching reaction process, reduces the production reagent cost, and simultaneously absorbs the difficult-to-handle sulfurized slag waste, so that efficient leaching of valuable metals such as nickel, cobalt, manganese and lithium is realized.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery recycling technology, specifically a method for co-processing waste lithium battery electrode powder and sulfide slag waste. Background Technology

[0002] Traditional industrial recycling processes for spent lithium-ion batteries typically involve first obtaining battery electrode powder rich in valuable metal elements through methods such as discharge, disassembly, crushing, heat treatment, and sorting. Then, a leaching agent is used to dissolve the metals, transferring them from the solid phase to the liquid phase. Chemical impurity removal and extraction methods are then used to separate the valuable metals, yielding related compound products. To improve metal recovery rates, the battery electrode powder usually undergoes high-temperature roasting pretreatment before being added to the leaching process. Reducing agents such as sodium metabisulfite, sulfur dioxide, and hydrogen peroxide are added during leaching to assist in the process, converting high-valence elements in the battery electrode powder to low-valence elements before they enter the solution. This process suffers from problems such as a long process flow, high reagent costs, the potential for toxic gas release, harsh operating environment, and high safety risks.

[0003] Therefore, researching a method for co-processing waste lithium battery electrode powder and sulfide slag is of great practical significance. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for the co-processing of waste lithium battery electrode powder and sulfide slag waste, comprising the following steps:

[0005] S1. Obtain lithium battery electrode powder and sulfide slag waste, wherein the lithium battery electrode powder includes lithium battery positive electrode powder;

[0006] S2. The lithium battery electrode powder and the sulfide slag waste are mixed in a mass ratio of (2-6):1 to obtain the first slurry;

[0007] S3. The first slurry is leached at high temperature using leaching acid, and then solid-liquid separation is performed to obtain leaching solution and leaching residue, and the leaching solution is recovered.

[0008] The lithium battery cathode powder includes lithium cobalt oxide and ternary nickel cobalt manganese oxide. The lithium battery cathode powder contains Co: 7wt%-10wt%, Ni: 25wt%-35wt%, Mn: 10wt%-15wt%, and Li: 6wt%-10wt%.

[0009] In step S1, the lithium battery electrode powder includes lithium battery positive electrode powder and lithium battery negative electrode powder. The lithium battery negative electrode powder is graphite powder. The lithium battery electrode powder contains Co: 3wt%-8wt%, Ni: 15wt%-26wt%, Mn: 3wt%-10wt%, Li: 2wt%-5wt%, and C: 15wt%-30wt%.

[0010] Following step S2, the following is also included:

[0011] S21. The first slurry is pre-leached at low temperature using pre-impregnation acid to obtain the second slurry.

[0012] Step S3 further includes: using the leaching acid to leach the second slurry at high temperature, then separating the solid and liquid to obtain the leaching residue and the leaching liquid, and recovering the leaching liquid.

[0013] In step S21, the pre-impregnation acid is sulfuric acid with a concentration of 1.0-3 mol / L, the reaction temperature of the low-temperature pre-impregnation is 60-80℃, the reaction time is 20-60 min, and the liquid-solid ratio is (5-9):1.

[0014] Furthermore, in step S21, the pre-impregnation acid is sulfuric acid, with a concentration of 1.0 mol / L, 2 mol / L, 3 mol / L, or a range between two of these; the low-temperature pre-impregnation reaction temperature is 60°C, 70°C, 80°C, or a range between two of these; the reaction time is 20 min, 30 min, 40 min, 50 min, 60 min, or a range between two of these; and the liquid-solid ratio is 5:1, 6:1, 7:1, 8:1, 9:1, or a range between two of these.

[0015] In step S1, the sulfide slag waste includes at least one of cobalt sulfide, nickel sulfide, and copper sulfide, and the sulfide slag includes S: 5wt%-8wt%, Co: 3wt%-10wt%, Ni: 2wt%-7wt%, and Cu: 1wt%-5wt%.

[0016] In step S3, the reaction temperature for high-temperature leaching is 110-160℃, and the reaction time is 2-5 hours.

[0017] Furthermore, in step S3, the reaction temperature of the high-temperature leaching is any one or a range between 110°C, 120°C, 130°C, 140°C, 150°C, and 160°C, and the reaction time is any one or a range between 2h, 3h, 4h, and 5h.

[0018] The step S3 is followed by:

[0019] S4. Wash the leaching residue to obtain a washing liquid and a washing residue. The washing liquid is used for slurry preparation in step S1. The mass fraction of valuable metals in the washing residue is less than 0.1 wt%. The valuable metals include at least one of cobalt, nickel, copper, and lithium. The washing residue includes graphite carbon residue.

[0020] In step S3, the leaching acid is sulfuric acid with a concentration of 1-3 mol / L.

[0021] The sulfidation slag waste is a byproduct of the sulfidation precipitation of the raffinate after P204 extraction to remove impurities and P507 nickel-cobalt separation in the cobalt-nickel wet refining process.

[0022] The leaching rate of the valuable metals, calculated based on the content of the valuable metals in the leaching residue and the leaching solution, can reach Ni≥96%, Co≥96%, Mn≥98%, and Li≥97%.

[0023] This invention mixes sulfide slag and lithium battery waste, eliminating the need for additional oxidants or reducing agents in the battery electrode powder leaching process. This reduces production reagent costs and simultaneously disposes of difficult-to-treat sulfide slag waste. It achieves highly efficient leaching of valuable metals such as nickel, cobalt, manganese, and lithium with a high leaching rate. The process is green, environmentally friendly, and free of secondary pollution, resulting in significant economic and environmental benefits. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating a specific embodiment of the present invention of a method for co-processing waste lithium battery electrode powder and sulfide slag waste.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This invention provides a method for the co-processing of waste lithium battery electrode powder and sulfide slag:

[0029] S1. Obtain lithium battery electrode powder and sulfide slag waste, wherein the lithium battery electrode powder includes lithium battery positive electrode powder;

[0030] The sulfide slag waste in the embodiments of the present invention is a by-product of the sulfide precipitation of the raffinate after P204 extraction to remove impurities and P507 nickel-cobalt separation in the cobalt-nickel wet refining process. It mainly includes: cobalt sulfide, nickel sulfide, and copper sulfide; the lithium battery cathode powder mainly includes at least one of: lithium cobalt oxide, ternary materials, and lithium iron phosphate.

[0031] S2. The lithium battery electrode powder and the sulfide slag waste are mixed in a mass ratio of (2-6):1 to obtain the first slurry;

[0032] The inventors of this invention discovered through research that battery electrode powder has relatively weak oxidizing properties. In order to improve the metal leaching rate in the synergistic leaching process, the mass ratio of the powder to cobalt sulfide slag is crucial, especially affecting the leaching rates of cobalt and lithium metals. When the mass ratio is too low, the metal leaching rate is low; when the mass ratio is too high, the lithium metal leaching rate will invert and gradually decrease.

[0033] S3. The first slurry is leached at high temperature using leaching acid, and then solid-liquid separation is performed to obtain leaching solution and leaching residue, and the leaching solution is recovered.

[0034] In some embodiments of the present invention, after step S2, i.e. before high-temperature leaching, the first slurry is pre-leached at low temperature using a pre-leaching acid to obtain a second slurry, which is then subjected to high-temperature leaching. The inventors have discovered that when lithium battery electrode powder includes both positive and negative electrode powders, when the first slurry is mixed and contacted with the leaching acid, lightweight carbon particles tend to aggregate on the solution surface to form a foam layer. The higher the temperature, the thicker the foam layer, which can easily lead to overflow. Therefore, to improve the safety of production operations, the first slurry can be pre-leached at low temperature, which can significantly reduce overflow in the leaching tank, thereby obtaining a second slurry with stable characteristics.

[0035] In the embodiments of the present invention, the concentration of sulfuric acid used as the leaching acid is also crucial. In some embodiments of the present invention, the sulfuric acid concentration ranges from 1.0 to 3 mol / L. The inventors have found through research that the sulfuric acid concentration has a significant impact on the leaching rates of cobalt and lithium metals. At low concentrations, the leaching rate of cobalt metal is low, but at high concentrations, the leaching rate of lithium metal decreases. In addition, excessively high sulfuric acid concentrations will increase the viscosity of the reaction system solution, reduce the effective mass transfer rate of metal ions, and increase the consumption of reagents.

[0036] In the embodiments of the present invention, sulfuric acid is used as the leaching solvent. While meeting the requirements for metal leaching rate, the reagent cost is low and the equipment corrosion is relatively weak.

[0037] The inventors discovered through research that when the reaction temperature is increased to above 110°C, the leaching rate of cobalt can be significantly increased compared to leaching at room temperature. When the reaction temperature is above 160°C, the leaching rates of nickel, cobalt, manganese, and lithium elements approach equilibrium, and further increasing the temperature is meaningless.

[0038] In some embodiments of the present invention, step S3 is followed by step S4, washing the leaching residue to obtain a washing liquid and a washing residue. The washing liquid is used for slurry preparation in step S1. The mass fraction of valuable metals in the washing residue is less than 0.1 wt%. The valuable metals include at least one of cobalt, nickel, copper, and lithium. The washing residue includes graphite carbon residue.

[0039] Please see Figure 1 , Figure 1 The flowchart below shows a method for co-processing waste lithium battery electrode powder and sulfide slag according to a specific embodiment of the present invention. It includes the steps of washing the leaching slag and returning the washing liquid to step S1 for slurry preparation.

[0040] Example 1

[0041] A method for co-processing waste lithium battery electrode powder and sulfide slag.

[0042] S1. Obtain lithium battery electrode powder and sulfide slag waste, wherein the lithium battery electrode powder includes lithium battery positive electrode powder and lithium battery negative electrode powder.

[0043] S2. The lithium battery electrode powder and the sulfide slag waste are mixed in a mass ratio of 3:1 to obtain the first slurry;

[0044] S21. The first slurry is pre-leached at low temperature using a pre-leaching acid to obtain a second slurry; the pre-leaching acid is sulfuric acid with a concentration of 2 mol / L, the reaction temperature of the low-temperature pre-leaching is 60℃, the reaction time is 20 min, and the liquid-solid ratio is 6:1.

[0045] S3. The second slurry is leached at high temperature using the leaching acid, and then the leaching residue and the leaching liquid are obtained by solid-liquid separation, and the leaching liquid is recovered; the reaction temperature of the high-temperature leaching is 150°C and the reaction time is 2 hours.

[0046] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 99.18%, 96.81%, 99.8% and 99.26%, respectively.

[0047] Example 2

[0048] A method for co-processing waste lithium battery electrode powder and sulfide slag.

[0049] S1. Obtain lithium battery electrode powder and sulfide slag waste, wherein the lithium battery electrode powder includes lithium battery positive electrode powder and lithium battery negative electrode powder.

[0050] S2. The lithium battery electrode powder and the sulfide slag waste are mixed in a mass ratio of 4:1 to obtain the first slurry.

[0051] S21. The first slurry is pre-leached at low temperature using a pre-leaching acid to obtain a second slurry; the pre-leaching acid is sulfuric acid with a concentration of 3 mol / L, the reaction temperature of the low-temperature pre-leaching is 80℃, the reaction time is 30 min, and the liquid-solid ratio is 5:1.

[0052] S3. The second slurry is leached at high temperature using the leaching acid, and then the leaching residue and the leaching liquid are obtained by solid-liquid separation, and the leaching liquid is recovered; the reaction temperature of the high-temperature leaching is 160°C and the reaction time is 2 hours.

[0053] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 99.69%, 99.21%, 99.82% and 99.45%, respectively.

[0054] Example 3

[0055] A method for co-processing waste lithium battery electrode powder and sulfide slag.

[0056] S1. Obtain lithium battery electrode powder and sulfide slag waste, wherein the lithium battery electrode powder includes lithium battery positive electrode powder and lithium battery negative electrode powder.

[0057] S2. The lithium battery electrode powder and the sulfide slag waste are mixed into a slurry at a mass ratio of 6:1 to obtain the first slurry.

[0058] S21. The first slurry is pre-leached at low temperature using a pre-leaching acid to obtain a second slurry; the pre-leaching acid is sulfuric acid with a concentration of 3 mol / L, the reaction temperature of the low-temperature pre-leaching is 60℃, the reaction time is 20 min, and the liquid-solid ratio is 5:1.

[0059] S3. The second slurry is leached at high temperature using the leaching acid, and then the leaching residue and the leaching liquid are obtained by solid-liquid separation, and the leaching liquid is recovered; the reaction temperature of the high-temperature leaching is 150°C and the reaction time is 5 hours.

[0060] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 99.41%, 98.77%, 99.54% and 98.53%, respectively.

[0061] Example 4

[0062] A method for co-processing waste lithium battery electrode powder and sulfide slag.

[0063] S1. Obtain lithium battery electrode powder and sulfide slag waste, wherein the lithium battery electrode powder includes lithium battery positive electrode powder and lithium battery negative electrode powder.

[0064] S2. The lithium battery electrode powder and the sulfide slag waste are mixed in a mass ratio of 3:1 to obtain the first slurry;

[0065] S21. The first slurry is pre-leached at low temperature using a pre-leaching acid to obtain a second slurry; the pre-leaching acid is sulfuric acid with a concentration of 1 mol / L, the reaction temperature of the low-temperature pre-leaching is 50°C, the reaction time is 60 min, and the liquid-to-solid ratio is 9:1.

[0066] S3. The second slurry is leached at high temperature using the leaching acid, and then the leaching residue and the leaching solution are obtained by solid-liquid separation, and the leaching solution is recovered; the reaction temperature of the high-temperature leaching is 110°C and the reaction time is 3 hours.

[0067] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 96.35%, 97.36%, 98.43% and 97.13%, respectively.

[0068] Example 5

[0069] A method for co-processing waste lithium battery electrode powder and sulfide slag.

[0070] S1. Obtain lithium battery electrode powder, wherein the lithium battery electrode powder is only lithium battery positive electrode powder.

[0071] S2. The lithium battery electrode powder and the sulfide slag waste are mixed in a mass ratio of 3:1 to obtain the first slurry;

[0072] S3. The first slurry is directly leached at high temperature using the leaching acid, and then the leaching residue and the leaching solution are obtained by solid-liquid separation, and the leaching solution is recovered; the leaching acid is sulfuric acid with a concentration of 3 mol / L, the reaction temperature of the high-temperature leaching is 140℃, the reaction time is 3h, and the liquid-solid ratio is 6:1.

[0073] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 99.24%, 98.96%, 99.13% and 99.44%, respectively.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that the waste lithium battery electrode powder is not mixed with sulfide slag waste to form a slurry.

[0076] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 88.95%, 80.54%, 91.24% and 88.25%, respectively.

[0077] Comparative Example 2

[0078] The difference from Example 1 is that the cobalt sulfide slag is not mixed with lithium battery electrode powder to form a slurry.

[0079] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni and Co were 91.25% and 90.54%, respectively.

[0080] Comparative Example 3

[0081] The difference from Example 2 is that the liquid-to-solid ratio is 3:1.

[0082] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 98.31%, 95.42%, 98.95% and 96.03%, respectively.

[0083] Comparative Example 4

[0084] The difference from Example 3 is that the temperature inside the high-temperature leaching vessel is 105°C.

[0085] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 98.89%, 91.22%, 99.35% and 98.22%, respectively.

[0086] Comparative Example 5

[0087] The difference from Example 4 is that the high-temperature leaching reaction time is 8 hours.

[0088] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 95.31%, 97.11%, 96.42% and 96.13%, respectively.

[0089] Comparative Example 6

[0090] The difference from Example 1 is as follows:

[0091] S1. Lithium battery electrode powder and sulfide slag waste are mixed in a mass ratio of 1:1 to obtain the first slurry;

[0092] S21. The first slurry is pre-leached at low temperature using a pre-leaching acid to obtain a second slurry; the pre-leaching acid is sulfuric acid with a concentration of 2 mol / L, the reaction temperature of the low-temperature pre-leaching is 40℃, the reaction time is 20 min, and the liquid-solid ratio is 4:1.

[0093] S3. The second slurry is leached at high temperature using the leaching acid, and then the leaching residue and the leaching solution are obtained by solid-liquid separation, and the leaching solution is recovered; the reaction temperature of the high-temperature leaching is 100°C and the reaction time is 1 hour.

[0094] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 86.73%, 76.51%, 89.12% and 85.89%, respectively.

[0095] Comparative Example 7

[0096] The difference from Example 1 is as follows:

[0097] S1. Lithium battery electrode powder and sulfide slag waste are mixed in a mass ratio of 7:1 to obtain the first slurry;

[0098] S21. The first slurry is pre-leached at low temperature using a pre-leaching acid to obtain a second slurry; the pre-leaching acid is sulfuric acid with a concentration of 2 mol / L, the reaction temperature of the low-temperature pre-leaching is 90℃, the reaction time is 20 min, and the liquid-solid ratio is 10:1.

[0099] S3. The second slurry is leached at high temperature using the leaching acid, and then the leaching residue and the leaching liquid are obtained by solid-liquid separation, and the leaching liquid is recovered; the reaction temperature of the high-temperature leaching is 170°C and the reaction time is 6 hours.

[0100] The leaching rates of valuable metals were detected and calculated. The leaching rates of Ni, Co, Mn and Li were 99.6%, 98.08%, 99.76% and 96.11%, respectively.

[0101] Please refer to Table 1, which compares the leaching rates of Examples 1-4 and Comparative Examples 1-5.

[0102] Table 1

[0103]

[0104] As can be seen from the data in Table 1, the waste lithium battery electrode powder treatment method provided by this invention fully utilizes the oxidizing properties of the waste lithium battery electrode powder material and the reducing properties of the sulfide slag waste. It adopts a method of first-stage room temperature pre-leaching followed by second-stage high-temperature continuous leaching. By leveraging the redox characteristics of the raw materials themselves, it achieves synergistic decomposition, realizing the efficient leaching of valuable elements such as nickel, cobalt, manganese, and lithium. The leaching rate can reach Ni≥96%, Co≥96%, Mn≥98%, and Li≥97%. The process does not require the addition of additional oxidants and reducing agents, has a short process flow, and has significant economic and environmental benefits.

[0105] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for co-processing waste lithium battery electrode powder and sulfide slag, characterized in that, Includes the following steps: S1. Obtain lithium battery electrode powder and sulfide slag waste, wherein the lithium battery electrode powder includes lithium battery positive electrode powder; S2. The lithium battery electrode powder and the sulfide slag waste are mixed at a mass ratio of (2-6):1 to obtain a first slurry. The first slurry is then pre-leached at low temperature using pre-leaching acid to obtain a second slurry. The pre-leaching acid is sulfuric acid with a concentration of 1.0-3 mol / L. The reaction temperature of the low-temperature pre-leaching is 60-80℃, the reaction time is 20-60 min, and the liquid-solid ratio is (5-9):

1. S3. The second slurry is leached at high temperature using leaching acid, and then solid-liquid separation is performed to obtain leaching residue and leaching solution, and the leaching solution is recovered; wherein, the leaching acid is sulfuric acid with a concentration of 1-3 mol / L, the reaction temperature of the high-temperature leaching is 110-160℃, and the reaction time is 2-5h.

2. The method for co-processing waste lithium battery electrode powder and sulfide slag waste according to claim 1, characterized in that, The lithium battery cathode powder includes: lithium cobalt oxide and ternary nickel cobalt manganese oxide. The lithium battery cathode powder contains Co: 7wt%-10wt%, Ni: 25wt%-35wt%, Mn: 10wt%-15wt%, and Li: 6wt%-10wt%.

3. The method for co-processing waste lithium battery electrode powder and sulfide slag waste according to claim 1, characterized in that, In step S1, the lithium battery electrode powder also includes lithium battery negative electrode powder, which is graphite powder. The lithium battery electrode powder includes Co: 3wt%-8wt%, Ni: 15wt%-26wt%, Mn: 3wt%-10wt%, Li: 2wt%-5wt%, and C: 15wt%-30wt%.

4. The method for co-processing waste lithium battery electrode powder and sulfide slag waste according to claim 1, characterized in that, In step S1, the sulfide slag waste includes cobalt sulfide, nickel sulfide, and copper sulfide. The sulfide slag contains S: 5wt%-8wt%, Co: 3wt%-10wt%, Ni: 2wt%-7wt%, and Cu: 1wt%-5wt%.

5. The method for co-processing waste lithium battery electrode powder and sulfide slag waste according to claim 4, characterized in that, Following step S3, the following is also included: S4. Wash the leaching residue to obtain a washing liquid and a washing residue. The washing liquid is used for slurry preparation in step S1. The mass fraction of valuable metals in the washing residue is less than 0.1 wt%. The valuable metals include at least one of cobalt, nickel, copper, and lithium. The washing residue includes graphite carbon residue.

6. The method for co-processing waste lithium battery electrode powder and sulfide slag waste according to claim 1, characterized in that, The sulfide slag waste is a byproduct of the sulfide precipitation of the raffinate after P204 extraction to remove impurities and P507 nickel-cobalt separation in the cobalt-nickel wet refining process.

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