Lithium battery recycling cement kiln high sealing castable and preparation method and application thereof

Abstract

The application provides a lithium battery recycling cement kiln high-sealing castable and a preparation method and application thereof, and relates to the technical field of castables. Each component includes the following mass fractions: 55-60 parts of lightweight mullite, 30-40 parts of quartz sand, 3-5 parts of microsilica, 12-15 parts of cement, 0.1-0.3 parts of sodium tripolyphosphate, and 0.03-0.05 parts of an anti-explosion agent. The castable has a low air permeability, which blocks the corrosion of corrosive gases on the steel shell and improves the service life of the lithium battery recycling cement kiln.

Description

Technical Field

[0001] This invention relates to the field of castable technology, specifically to a high-sealing castable for lithium battery recycling cement kilns, its preparation method, and its application. Background Technology

[0002] Since the launch of the first commercial lithium-ion battery in 1991, global demand for lithium-ion batteries has been steadily increasing. In 2021, total global lithium-ion battery shipments reached 562.4 GWh, and are projected to reach 1223 GWh by 2025. Currently, the main cathode materials for lithium-ion batteries are lithium nickel manganese cobalt oxide, lithium cobalt oxide, and lithium iron phosphate. The lifespan of lithium-ion batteries is typically 3-7 years. Therefore, as the lithium-ion battery market continues to expand, a large number of used lithium-ion batteries urgently require industrial-scale processing.

[0003] Currently, the main sources of spent lithium batteries include retired lithium batteries and defective, substandard, and experimental products manufactured by battery manufacturers. The recycling of spent lithium batteries typically involves processes such as preheating, crushing and sorting, roasting, dissolving, and evaporation crystallization. The roasting process transforms the non-oxides of metals such as Ni, Co, Mn, Li, Cu, and Al in the spent batteries into metal oxides. These metal oxides are then transferred to solution or reduced to their metallic state during subsequent processing, thus being extracted.

[0004] Low-cement castables are widely used in cement kilns due to their high strength, wear resistance, thermal shock resistance, erosion resistance, and impermeability, as well as their strong volume stability and low water consumption during construction. However, corrosive gases are generated during lithium battery roasting. If the castable has poor sealing, these gases can permeate through the castable and contact the steel shell, causing corrosion of the cement kiln's steel shell under high temperatures and reducing its service life. Furthermore, the poor sealing performance of existing low-cement castables results in a shorter service life for lithium battery recycling cement kilns. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a high-sealing castable for lithium battery recycling cement kilns, its preparation method, and its application, solving the technical problem of poor sealing performance of existing low-cement castables.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A high-sealing castable refractory comprises the following components in parts by weight:

[0010]

[0011] Preferably, the light mullite has a particle size distribution of 0.1 mm to 5 mm, wherein the mass ratio of light mullite with particle sizes of 0.1 mm to 1 mm, 1 mm to 3 mm, and 3 mm to 5 mm is (5-7):(20-22):(30-31).

[0012] Preferably, the particle size distribution of the quartz sand is 0.1 mesh-200 mesh, wherein the mass ratio of quartz sand with particle sizes of 0.1 mesh-0.5 mesh, 0.5 mesh-10.5 mesh, 10.5 mesh-100 mesh, and 100 mesh-200 mesh is (3-5):(7-10):(6-8):(14-17).

[0013] Preferably, the cement is selected from pure calcium aluminate cement.

[0014] Preferably, the micro silica fume is grade 95.

[0015] Preferably, the explosion retardant is selected from at least one of metallic aluminum powder and azodicarbonamide.

[0016] On the other hand, a method for preparing a high-sealing castable involves mixing the components evenly, adding water and stirring, and then self-flowing and molding the mixture.

[0017] On the other hand, a high-sealing castable is used in the preparation of lithium battery recycling cement kilns, wherein the high-sealing castable has an air permeability of (1.5-2.1)×10⁻⁶. 4 m 2 .

[0018] (III) Beneficial Effects

[0019] This invention provides a high-sealing castable for lithium battery recycling cement kilns and its preparation method. Compared with the prior art, it has the following advantages:

[0020] 1. The high-sealing castable of this invention includes quartz sand with a particle size distribution of 0.1 mesh-200 mesh. The mass ratio of quartz sand with particle sizes of 0.1 mesh-0.5 mesh, 0.5 mesh-10.5 mesh, 10.5 mesh-100 mesh, and 100 mesh-200 mesh is (3-5):(7-10):(6-8):(14-17). Through scientific gradation, quartz sand particles and fine powder are added. This utilizes the volume change caused by the crystal transformation of quartz sand at high temperatures to achieve an average linear expansion coefficient of (8.1-8.9)×10⁻⁶. -6 / ℃, meeting the requirement of synchronous expansion with the steel shell, ensuring the integrity and sealing of the lining; on the other hand, the combination of quartz sand of different particle sizes improves the density of the castable, thereby ensuring its low air permeability, blocking corrosive gases from corroding the steel shell, and improving the service life of the lithium battery recycling cement kiln.

[0021] 2. The high-sealing castable of the present invention includes lightweight high-strength mullite. By selecting lightweight high-strength mullite hollow spheres as aggregate, the basic strength of the high-sealing castable is guaranteed, and lightweighting and thermal conductivity are achieved.

[0022] 3. The high-sealing castable of the present invention includes pure calcium aluminate cement as a binder, which avoids the mid-temperature strength decay defect of ordinary high-alumina cement and ensures that the strength of the high-sealing castable does not decrease at the operating temperature. Detailed Implementation

[0023] 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 are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all 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.

[0024] This application provides a high-sealing castable for lithium battery recycling cement kilns, its preparation method, and its application, solving the problem that the density of existing low-cement castables cannot meet the requirements of lithium battery recycling cement kilns.

[0025] The technical solution in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0026] 1. The high-sealing castable of this invention includes quartz sand with a particle size distribution of 0.1 mesh-200 mesh. The mass ratio of quartz sand with particle sizes of 0.1 mesh-0.5 mesh, 0.5 mesh-10.5 mesh, 10.5 mesh-100 mesh, and 100 mesh-200 mesh is (3-5):(7-10):(6-8):(14-17). Through scientific gradation, quartz sand particles and fine powder are added. This utilizes the volume change caused by the crystal transformation of quartz sand at high temperatures to achieve an average linear expansion coefficient of (8.1-8.9)×10⁻⁶. -6 / ℃, meeting the requirement of synchronous expansion with the steel shell, ensuring the integrity and sealing of the lining; on the other hand, the combination of quartz sand of different particle sizes improves the density of the castable, thereby ensuring its low air permeability, blocking corrosive gases from corroding the steel shell, and improving the service life of the lithium battery recycling cement kiln.

[0027] 2. The high-sealing castable of the present invention includes lightweight high-strength mullite. By selecting lightweight high-strength mullite hollow spheres as aggregate, the basic strength of the high-sealing castable is guaranteed, and lightweighting and thermal conductivity are achieved.

[0028] 3. The high-sealing castable of the present invention includes pure calcium aluminate cement as a binder, which avoids the mid-temperature strength decay defect of ordinary high-alumina cement and ensures that the strength of the high-sealing castable does not decrease at the operating temperature.

[0029] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0030] Example 1:

[0031] This embodiment provides a high-sealing castable, comprising the following components:

[0032]

[0033] The particle size distribution of lightweight mullite is 0.1mm-5mm, and the mass ratio of lightweight mullite with particle sizes of 0.1mm-1mm, 1mm-3mm, and 3-5mm is 5:20:30.

[0034] The particle size distribution of the quartz sand is 0.1 mesh-200 mesh, and the mass ratio of quartz sand with particle sizes of 0.1 mesh-0.5 mesh, 0.5 mesh-10.5 mesh, 10.5 mesh-100 mesh, and 100 mesh-200 mesh is 3:7:6:14.

[0035] After the components are mixed evenly, water is added and stirred. After stirring evenly, the mixture is allowed to flow and solidify.

[0036] Example 2:

[0037] This embodiment provides a high-sealing castable, comprising the following components:

[0038]

[0039] The particle size distribution of lightweight mullite is 0.1mm-5mm, and the mass ratio of lightweight mullite with particle sizes of 0.1mm-1mm, 1mm-3mm, and 3-5mm is 6:21:30.5.

[0040] The particle size distribution of the quartz sand is 0.1 mesh-200 mesh, and the mass ratio of quartz sand with particle sizes of 0.1 mesh-0.5 mesh, 0.5 mesh-10.5 mesh, 10.5 mesh-100 mesh, and 100 mesh-200 mesh is 4:8:7:15.

[0041] After the components are mixed evenly, water is added and stirred. After stirring evenly, the mixture is allowed to flow and solidify.

[0042] Example 3:

[0043] This embodiment provides a high-sealing castable, comprising the following components:

[0044]

[0045] 0.05 parts of azodicarbonamide.

[0046] The particle size distribution of lightweight mullite is 0.1mm-5mm, and the mass ratio of lightweight mullite with particle sizes of 0.1mm-1mm, 1mm-3mm, and 3-5mm is 7:22:31.

[0047] The particle size distribution of the quartz sand is 0.1 mesh-200 mesh, and the mass ratio of quartz sand with particle sizes of 0.1 mesh-0.5 mesh, 0.5 mesh-10.5 mesh, 10.5 mesh-100 mesh, and 100 mesh-200 mesh is 5:10:8:17.

[0048] After the components are mixed evenly, water is added and stirred. After stirring evenly, the mixture is allowed to flow and solidify.

[0049] Comparative Example 1:

[0050] The difference between this comparative example and Example 1 is that the particle size of the quartz sand is 200 mesh.

[0051] Comparative Example 2:

[0052] The difference between this comparative example and Example 1 is that the particle size of the quartz sand is 0.1 mesh.

[0053] Test case

[0054] The performance of the high-sealing castables prepared in Examples 1-3 and Comparative Examples 1 and 2 was tested. The test methods are as follows, and the results are shown in Table 1.

[0055] Sample preparation: The high-sealing castables prepared in Examples 1-3 and Comparative Examples 1 and 2 were self-formed into 40mm×40mm×160mm strips, φ180mm×(20-25)mm discs, and φ50mm×50mm and φ10mm×50mm cylinders. After curing at room temperature for 24 hours, the samples were demolded and dried at 110℃ for 24 hours.

[0056] 1. Density:

[0057] The air permeability of a φ50mm×50mm cylinder after drying at 350℃ under a pressure of 15KPa was measured according to GB / T 3000-2016.

[0058] 2. Average linear expansion coefficient:

[0059] The average linear expansion coefficient of a φ10mm×50mm cylinder after heat treatment at 1200℃ at 200℃ was measured according to GB / T 7320-2018.

[0060] 3. Strength:

[0061] The room temperature flexural strength and room temperature compressive strength of a 40mm×40mm×160mm specimen after drying at 110℃ and heat treatment at 1200℃ were measured according to GB / T 4513.6-2017.

[0062] 4. Thermal insulation performance:

[0063] The thermal conductivity of a φ180mm×(20-25)mm disk after heat treatment at 1200℃ was measured using a PBD-12-4P thermal conductivity meter at a surface temperature of 500℃.

[0064] Table 1. Performance test results of the high-sealing castables prepared in Examples 1-3 and Comparative Examples 1 and 2.

[0065]

[0066] Analysis of Table 2 shows that, compared with Examples 1-3, the castables of Comparative Examples 1 and 2 have lower average linear expansion coefficients and higher air permeability. This indicates that in this invention, quartz sand of different particle sizes works synergistically to increase the average linear expansion coefficient of the castable and reduce its air permeability.

[0067] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-sealing castable for lithium battery recycling cement kilns, characterized in that, The components include the following parts by weight: The quartz sand has a particle size distribution of 0.1 mesh to 200 mesh, wherein the mass ratio of quartz sand with particle sizes of 0.1 mesh to 0.5 mesh, 0.5 mesh to 10.5 mesh, 10.5 mesh to 100 mesh, and 100 mesh to 200 mesh is (3-5):(7-10):(6-8):(14-17).

2. The high-sealing castable for lithium battery recycling cement kilns as described in claim 1, characterized in that, The light mullite has a particle size distribution of 0.1 mm to 5 mm, wherein the mass ratio of light mullite with particle sizes of 0.1 mm to 1 mm, 1 mm to 3 mm, and 3 mm to 5 mm is (5-7):(20-22):(30-31).

3. The high-sealing castable for lithium battery recycling cement kilns as described in claim 1, characterized in that, The cement is selected from pure calcium aluminate cement.

4. The high-sealing castable for lithium battery recycling cement kilns as described in claim 1, characterized in that, The micro silica fume is grade 95.

5. The high-sealing castable for lithium battery recycling cement kilns as described in claim 1, characterized in that, The explosion-proof agent is selected from at least one of metallic aluminum powder and azodicarbonamide.

6. A method for preparing a high-sealing castable for lithium battery recycling cement kilns as described in any one of claims 1-5, characterized in that, After the components are mixed evenly, water is added and stirred. After stirring evenly, the mixture is self-flowing and molded to obtain the final product.

7. The application of the high-sealing castable for lithium battery recycling cement kilns according to any one of claims 1-5 in the preparation of lithium battery recycling cement kilns, characterized in that, The air permeability of the high-sealing castable is (1.5-2.1)×10⁻⁶. 4 m 2 .

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