Method for recycling waste saggar and saggar resistant to erosion of lithium battery material

Abstract

The invention provides a method for recycling a waste sagger and a sagger resistant to erosion of a lithium battery material. The method for recycling the waste saggar comprises the following steps: (1) separating an erosion layer from a matrix of the waste saggar, and crushing to obtain erosion layer fine powder and matrix fine powder; (2) coating mixed fine powder containing the erosion layer fine powder, an adhesive and a solvent are sequentially added into coating mixed aggregate, and a coating mixture is obtained; (3) sequentially adding bulk mixed fine powder containing the matrix fine powder, an adhesive and a solvent into the bulk mixed aggregate to obtain a bulk mixture; (4) sealing and ageing to respectively obtain a body aged material and a coating aged material; (5) the coating stale material is flatly laid at the bottom of a mold, then the mold is filled with a body stale material, compression molding and drying are conducted, and a green body is obtained; and (6) sintering the green body to obtain the sagger resistant to erosion of the lithium battery material. According to the method, efficient recycling of the waste saggar is achieved, and the saggar resistant to corrosion of the lithium battery material is prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, in particular to the preparation of electrode materials, and in particular to a method for recycling waste saggers and a sagger resistant to corrosion by lithium-ion batteries. Background Art

[0002] At present, the high-temperature solid-phase method is widely used in the industry to prepare lithium-ion battery positive electrode materials. During the high-temperature calcination process of the ternary positive electrode materials, the alkaline positive electrode materials and the sagger components are prone to corrosion reactions, generating lithium-containing corrosion phases such as LiAlO2, LiAlSiO4, and Li2SiO3. The formation of these lithium-containing corrosion products not only causes volume expansion, but also because their thermal expansion coefficients are significantly different from those of the sagger matrix, they are prone to cause structural failure problems such as peeling and cracking of the sagger surface after multiple thermal cycles.

[0003] CN11297929 discloses a coating for repairing used saggers and a method for using the same. The coating comprises the following raw materials in parts by weight: 30-70 parts fused white corundum powder, 1-10 parts mullite powder, 8-30 parts binding clay, 0-5 parts spodumene, 1-5 parts zirconium oxide, 5-25 parts α-Al2O3 micropowder, 1-20 parts magnesia-alumina spinel powder, 2-8 parts colloidal sol, 1-5 parts binder, 0.1-1 parts water reducer, and 16-22 parts water. The method comprises preparing the coating, polishing the used sagger, and repairing the used sagger to obtain a regenerated new sagger. The repaired sagger can be put back into use and has high strength, strong corrosion resistance, and good thermal shock resistance.

[0004] CN115838542A discloses a repair coating, its use method, and its application in repairing lithium manganese oxide saggers. Using washed kaolin, alumina, and water glass as raw materials, the invention features a simple preparation process, simple ingredients, minimal binder usage, high bond strength, and resistance to blistering and peeling. This reduces contact between the lithium manganese oxide positive electrode material and the binder, effectively preventing contamination of the lithium manganese oxide positive electrode material and ensuring its quality.

[0005] CN109746776A discloses a device for grinding the inner wall of a waste battery box to recover rare metals. The invention rotates a grinding rod and extends it into the battery box body to grind the inner wall of the battery box body and wipe off the rare metals on the inner wall. Under the rotation of the turntable, when the opening of the polished battery box body faces downward, the ground-off powder falls to the bottom of the grinding box body under the action of gravity. The entire operation process is simple, highly intelligent and efficient.

[0006] In the prior art, only the metal materials remaining on the surface of the waste saggers are recycled, while the main body is less utilized, resulting in a low utilization rate of the waste saggers. Therefore, it is of great significance to provide a method for efficiently recycling waste saggers and preparing long-life saggers. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a method for recycling waste saggers and a sagger resistant to corrosion by lithium battery materials. The present invention separates the erosion layer from the base of the waste sagger, prepares erosion layer fine powder and base fine powder respectively, and mixes them into the coating mixed fine powder and the main body mixed fine powder for utilization, thereby achieving efficient recycling of waste saggers and significantly reducing the cost of raw materials; the erosion layer fine powder is used as the functional component of the anti-corrosion coating, based on the lithium-containing phase in the erosion layer fine powder and the Li in the lithium battery material. + The chemical inertness of the coating significantly improves the corrosion resistance of the coating, and a sagger resistant to corrosion by lithium battery materials is prepared.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for recycling waste saggers, the method comprising:

[0010] (1) Separating and crushing the erosion layer and the matrix of the waste sagger to obtain erosion layer fine powder and matrix fine powder;

[0011] (2) adding coating mixed fine powder, a binder, and a solvent to the coating mixed aggregate in sequence to obtain a coating mixture; wherein the coating mixed fine powder includes the erosion layer fine powder;

[0012] (3) adding bulk mixed fine powder, a binder, and a solvent to the bulk mixed aggregate in sequence to obtain a bulk mixed material; the bulk mixed fine powder includes the matrix fine powder;

[0013] (4) sealing the coating mixture and the body mixture to obtain body stale material and coating stale material respectively;

[0014] (5) spreading the coating stale material on the bottom of the mold, then filling the body stale material, pressing and forming, and drying to obtain a green body;

[0015] (6) sintering the green body to obtain a sagger resistant to erosion by lithium battery materials;

[0016] The order of steps (2) and (3) is not critical.

[0017] The present invention separates the erosion layer from the matrix of the waste sagger, prepares erosion layer fine powder and matrix fine powder respectively, and mixes them into coating mixed fine powder and body mixed fine powder respectively for utilization, thereby realizing efficient recycling of waste sagger and greatly reducing the cost of raw materials; the erosion layer fine powder is used as the functional component of the anti-erosion coating, based on the lithium-containing phase in the erosion layer fine powder and the Li in the lithium battery material, the erosion layer fine powder is recycled. + The chemical inertness of the coating significantly improves the corrosion resistance of the coating.

[0018] The present invention utilizes a coating mixed aggregate and a coating mixed fine powder to create a densified structure, reducing the apparent porosity of the sagger, effectively inhibiting the penetration and diffusion of the cathode material, and extending the service life of the sagger. The present invention utilizes a one-step compression molding process combined with a one-step sintering process to simultaneously achieve efficient composite formation of the coating and the body, combining the advantages of a simple process flow and low production costs.

[0019] The present invention further designs the components of the coating and selects a coating mixed aggregate including magnesium aluminum spinel, mullite and corundum. The prepared coating can undergo an interfacial reaction with the active lithium component in the lithium battery material during service to form a stable LiAlO2 or LiAlSiO4 interfacial erosion layer. This erosion layer can effectively inhibit the chemical erosion of the sagger by the highly active lithium component in the positive electrode material.

[0020] Preferably, the coating mixed aggregate includes a first cordierite aggregate, a first mullite aggregate, a first corundum aggregate and a magnesia-alumina spinel aggregate.

[0021] In the present invention, the size of the aggregate is characterized by particle size, which indicates the range of particles between two particle sizes (particle diameters). For example, 2-0.5 mm indicates that the particle size is less than 2 mm and greater than 0.5 mm. For example, 1-0 mm indicates that the particle size is less than 1 mm and greater than 0 mm. In the present invention, "0 mm" specifically refers to particles with a particle size of less than 1 μm.

[0022] Preferably, the particle size of the first cordierite aggregate is 2-0.2 mm.

[0023] Preferably, the particle size of the first mullite aggregate is 2-0.2 mm.

[0024] Preferably, the particle size of the first corundum aggregate is 1-0 mm.

[0025] Preferably, the particle size of the magnesia-alumina spinel aggregate is 1-0 mm.

[0026] Preferably, in the coating mixed aggregate, the mass ratio of the first cordierite aggregate, the first mullite aggregate, the first corundum aggregate and the magnesia-alumina spinel aggregate is 1:(1-3):(0.5-2):(0.5-2).

[0027] Preferably, the coating mixed fine powder includes first mullite fine powder, magnesia alumina spinel fine powder, first corundum fine powder, first alumina fine powder, zirconium oxide, first clay and the erosion layer fine powder.

[0028] Preferably, in the coating mixed fine powder, the average particle size of the first mullite fine powder, the magnesia alumina spinel fine powder, the first corundum fine powder, the first alumina fine powder and the zirconia fine powder is independently 45 μm or less.

[0029] Preferably, the average particle size of the first alumina powder is ≤1 μm.

[0030] Preferably, in the coating mixed fine powder, the mass ratio of the first mullite fine powder, magnesia-alumina spinel fine powder, the first corundum fine powder, the first alumina fine powder, zirconia, clay, erosion layer fine powder and the first cordierite aggregate in the coating mixed aggregate is (0.75-3):(0.25-1):(0.5-2):(0.05-1):(0.05-1):(0.05-1):(0.05-1):1.

[0031] Preferably, the bulk mixed aggregate includes a second cordierite aggregate, a second mullite aggregate and a second corundum aggregate.

[0032] Preferably, the particle size of the second cordierite aggregate is 2-0.2 mm.

[0033] Preferably, the particle size of the second mullite aggregate is 2-0.2 mm.

[0034] Preferably, the particle size of the second corundum aggregate is 1-0 mm.

[0035] Preferably, in the bulk mixed aggregate, the mass ratio of the second cordierite aggregate, the second mullite aggregate and the second corundum aggregate is 1:(0.75-3):(0.5-2).

[0036] Preferably, the bulk mixed fine powder includes a second mullite fine powder, a second corundum fine powder, a second alumina fine powder, a second clay and the matrix fine powder.

[0037] Preferably, the average particle size of the second mullite fine powder, the second corundum fine powder, and the second alumina fine powder are each independently 45 μm or less.

[0038] Preferably, in the bulk mixed fine powder, the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the bulk mixed aggregate is (1-3):(0.5-2):(0.05-1):(0.05-1):(0.5-2):1.

[0039] Preferably, the element composition of the erosion layer fine powder includes Li and M, and the M includes any one or a combination of at least two of Al, Si, Co, Mn or Ni.

[0040] Preferably, the material of the matrix fine powder includes one or a combination of at least two of Al2O3, MgO or SiO2.

[0041] Preferably, the average particle size of the eroded layer fine powder and the matrix fine powder is independently 180 μm or less.

[0042] Preferably, the material of the first cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles.

[0043] Preferably, in the first cordierite aggregate, the mass ratio of 2-1 mm cordierite particles to 1.5-0.2 mm cordierite particles is 1:(0.1-10).

[0044] Preferably, the material of the first mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles.

[0045] Preferably, in the first mullite aggregate, the mass ratio of 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles is 1:(0.5-15):(0.1-10).

[0046] Preferably, the material of the first corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles.

[0047] Preferably, in the first corundum aggregate, the mass ratio of 1-0 mm corundum particles to 1-0.5 mm corundum particles is 1:(0.1-10).

[0048] Preferably, the material of the magnesia-alumina spinel aggregate includes 1-0 mm magnesia-alumina spinel particles and 1-0.5 mm magnesia-alumina spinel particles.

[0049] Preferably, in the magnesia-alumina spinel aggregate, the mass ratio of 1-0 mm magnesia-alumina spinel particles to 1-0.5 mm magnesia-alumina spinel particles is 1:(0.1-10).

[0050] Preferably, the material of the second cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles.

[0051] Preferably, in the second cordierite aggregate, the mass ratio of 2-1 mm cordierite particles to 1.5-0.2 mm cordierite particles is 1:(0.1-10).

[0052] Preferably, the material of the second mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles.

[0053] Preferably, in the second mullite aggregate, the mass ratio of 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles is 1:(0.3-15):(0.067-15).

[0054] Preferably, the material of the second corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles.

[0055] Preferably, in the second corundum aggregate, the mass ratio of 1-0 mm corundum particles to 1-0 mm corundum particles is 1:(0.1-15).

[0056] Preferably, the sealing time is more than 12 hours.

[0057] Preferably, the compression molding pressure is 10 MPa to 40 MPa.

[0058] Preferably, the sintering temperature is 1200°C to 1300°C.

[0059] Preferably, the sintering time is 2 hours to 6 hours.

[0060] Preferably, the cooling method of the sintering is furnace cooling.

[0061] In a second aspect, the present invention provides a sagger resistant to corrosion by lithium battery materials, wherein the sagger is prepared by the method for recycling waste saggers described in the first aspect.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] (1) The method provided by the present invention separates the erosion layer of the waste sagger from the matrix and back-mixes it into the main body mixed fine powder, thereby realizing the efficient recycling of the waste sagger and greatly reducing the cost of raw materials; at the same time, the erosion layer fine powder is used as the functional component of the anti-erosion coating, based on the lithium-containing phase in the erosion layer fine powder and the Li in the lithium battery material. + The chemical inertness of the coating significantly improves the corrosion resistance of the coating.

[0064] (2) The present invention optimizes the particle grading and composition design of the sagger coating, reduces the apparent porosity of the sagger, effectively inhibits the penetration and diffusion of the positive electrode material, and improves the service life of the sagger.

[0065] (3) The present invention adopts a one-step pressing and molding process combined with a one-step sintering process to simultaneously achieve efficient composite of the coating and the body, and has the advantages of a simple process flow and low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a flow chart of preparing a sagger resistant to corrosion by lithium battery materials from waste saggers provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0067] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions.

[0069] In the description of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly indicate the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0070] In one embodiment, the present invention provides a method for recycling waste saggers, the method comprising:

[0071] (1) Separating and crushing the erosion layer and the matrix of the waste sagger to obtain erosion layer fine powder and matrix fine powder;

[0072] (2) adding coating mixed fine powder, a binder, and a solvent to the coating mixed aggregate in sequence to obtain a coating mixture; wherein the coating mixed fine powder includes the erosion layer fine powder;

[0073] (3) adding bulk mixed fine powder, a binder, and a solvent to the bulk mixed aggregate in sequence to obtain a bulk mixed material; the bulk mixed fine powder includes the matrix fine powder;

[0074] (4) sealing the coating mixture and the body mixture to obtain body stale material and coating stale material respectively;

[0075] (5) spreading the coating stale material on the bottom of the mold, then filling the body stale material, pressing and forming, and drying to obtain a green body;

[0076] (6) sintering the green body to obtain a sagger resistant to erosion by lithium battery materials;

[0077] The order of steps (2) and (3) is not critical.

[0078] The present invention separates the erosion layer from the matrix of the waste sagger, prepares erosion layer fine powder and matrix fine powder respectively, and mixes them into coating mixed fine powder and body mixed fine powder respectively for utilization, thereby realizing efficient recycling of waste sagger and greatly reducing the cost of raw materials; the erosion layer fine powder is used as the functional component of the anti-erosion coating, based on the lithium-containing phase in the erosion layer fine powder and the Li in the lithium battery material, the erosion layer fine powder is recycled. + The chemical inertness of the coating significantly improves the corrosion resistance of the coating.

[0079] The present invention utilizes a coating mixed aggregate and a coating mixed fine powder to create a densified structure, reducing the apparent porosity of the sagger, effectively inhibiting the penetration and diffusion of the cathode material, and extending the service life of the sagger. The present invention utilizes a one-step compression molding process combined with a one-step sintering process to simultaneously achieve efficient composite formation of the coating and the body, combining the advantages of a simple process flow and low production costs.

[0080] The present invention further designs the components of the coating and selects a coating mixed aggregate including magnesium aluminum spinel, mullite and corundum of a specific particle size. The prepared coating can undergo an interfacial reaction with the active lithium component in the lithium battery material during service to form a stable LiAlO2 or LiAlSiO4 interfacial corrosion layer. This corrosion layer can effectively inhibit the chemical corrosion of the sagger by the highly active lithium component in the positive electrode material.

[0081] In some embodiments, the binder comprises dextrin.

[0082] In some embodiments, the solvent comprises water.

[0083] In some embodiments, the coating mixed aggregate includes a first cordierite aggregate, a first mullite aggregate, a first corundum aggregate, and a magnesia-alumina spinel aggregate.

[0084] In some embodiments, the particle size of the first cordierite aggregate is 2-0.2 mm.

[0085] In some embodiments, the particle size of the first mullite aggregate is 2-0.2 mm.

[0086] In some embodiments, the particle size of the first corundum aggregate is 1-0 mm.

[0087] In some embodiments, the particle size of the magnesia-alumina spinel aggregate is 1-0 mm.

[0088] In some embodiments, in the coating mixed aggregate, the mass ratio of the first cordierite aggregate, the first mullite aggregate, the first corundum aggregate and the magnesia-alumina spinel aggregate is 1:(1-3):(0.5-2):(0.5-2), for example, it can be 1:1:0.5:0.5, 1:1.25:0.75:1, 1:1.5:1:1.2, 1:1.75:1.25:1.4, 1:2:1.5:1.6, 1:2.5:1.75:1.8 or 1:3:2:2, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0089] In some embodiments, the coating mixed fine powder includes a first mullite fine powder, a magnesium aluminum spinel fine powder, a first corundum fine powder, a first alumina fine powder, zirconium oxide, a first clay, and the erosion layer fine powder.

[0090] In some embodiments, in the coating mixed fine powder, the average particle size of the first mullite fine powder, the magnesia spinel fine powder, the first corundum fine powder, the first alumina fine powder and the zirconia is independently less than 45 μm, for example, it can be 45 μm, 44 μm, 43 μm, 42 μm, 41 μm, 40 μm, 35 μm, 30 μm or 20 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0091] In some embodiments, the average particle size of the first alumina fine powder is ≤1 μm, for example, 1 μm, 0.8 μm, 0.6 μm or 0.5 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0092] In some embodiments, in the coating mixed fine powder, the mass ratio of the first mullite fine powder, the magnesia-alumina spinel fine powder, the first corundum fine powder, the first alumina fine powder, the zirconia, the clay, the erosion layer fine powder and the first cordierite aggregate in the coating mixed aggregate is (0.75-3):(0.25-1):(0.5-2):(0.05-1):(0.05-1):(0.05-1):(0.05-1):1, for example, it can be 0.75:0.25:0.5:0.05:0.05:0.05:1, 1:0.35:0.75:0.1:0.1:0.1, 1.5:0.5:1:0.3:0.25:0.2:1, 2:0.65:1.25:0.5:0.5:0.6:1 , 2.5:0.85:1.5:0.75:0.75:0.8:1 or 3:1:2:1:1:1:1, including but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0093] In some embodiments, the bulk mixed aggregate includes a second cordierite aggregate, a second mullite aggregate, and a second corundum aggregate.

[0094] In some embodiments, the particle size of the second cordierite aggregate is 2-0.2 mm.

[0095] In some embodiments, the particle size of the second mullite aggregate is 2-0.2 mm.

[0096] In some embodiments, the particle size of the second corundum aggregate is 1-0 mm.

[0097] In some embodiments, in the bulk mixed aggregate, the mass ratio of the second cordierite aggregate, the second mullite aggregate, and the second corundum aggregate is 1:(0.75-3):(0.5-2), for example, it can be 1:0.75:0.5, 1:1:0.75, 1:1.5:1.25, 1:2:1.5, 1:2.5:1.75 or 1:3:2, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0098] In some embodiments, the bulk mixed fine powder includes a second mullite fine powder, a second corundum fine powder, a second alumina fine powder, a second clay, and the matrix fine powder.

[0099] In some embodiments, the average particle size of the second mullite fine powder, the second corundum fine powder, and the second alumina fine powder are each independently less than 45 μm, for example, 45 μm, 44 μm, 43 μm, 42 μm, 41 μm, 40 μm, 35 μm, 30 μm, or 20 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0100] In some embodiments, the average particle size of the first alumina fine powder is ≤1 μm, for example, 1 μm, 0.8 μm, 0.6 μm or 0.5 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0101] In some embodiments, in the bulk mixed fine powder, the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the bulk mixed aggregate is (1-3):(0.5-2):(0.05-1):(0.05-1):(0.5-2):1, for example, it can be 1:0.5:0.05:0.05:0.05:1, 1.5:1:0.1:0.125:0.5:1, 2:1.25:0.25:0.25:1:1, 2.5:1.5:0.75:0.5:1.5:1 or 3:2:1:1:2:1, including but not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable.

[0102] In some embodiments, the elemental composition of the erosion layer fine powder includes Li and M, and the M includes any one or a combination of at least two of Al, Si, Co, Mn or Ni. Typical but non-limiting combinations include a combination of Al and Si, a combination of Co and Mn, or a combination of Ni and Co.

[0103] In some embodiments, the material of the matrix fine powder includes one or a combination of at least two of Al2O3, MgO or SiO2. Typical but non-limiting combinations include a combination of Al2O3 and MgO, a combination of SiO2 and Al2O3, or a combination of Al2O3, MgO and SiO2.

[0104] In some embodiments, the average particle size of the erosion layer fine powder and the matrix fine powder is independently less than 180 μm, for example, it can be 180 μm, 170 μm, 160 μm, 150 μm, 140 μm, 130 μm, 120 μm, 110 μm, 100 μm or 50 μm, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0105] In some embodiments, the material of the first cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles, and the mass ratio of the 2-1 mm cordierite particles to the 1.5-0.2 mm cordierite particles is 1:(0.1-10), for example, it can be 1:0.1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0106] In some embodiments, the material of the first mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles, and the mass ratio of the 2-1 mm mullite particles, the 1-0.2 mm mullite particles and the 1.5-0.2 mm mullite particles is 1:(0.5-15):(0.1-10), for example, it can be 1:0.5:0.1, 1:1:1, 1:3:2, 1:5:3, 1:7:4, 1:9:5, 1:11:6, 1:13:8 or 1:15:10, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0107] In some embodiments, the material of the first corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles, and the mass ratio of the 1-0 mm corundum particles to the 1-0.5 mm corundum particles is 1:(0.1-10), for example, it can be 1:0.1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0108] In some embodiments, the material of the magnesia-alumina spinel aggregate includes 1-0 mm magnesia-alumina spinel particles and 1-0.5 mm magnesia-alumina spinel particles, and the mass ratio of the 1-0 mm magnesia-alumina spinel particles to the 1-0.5 mm magnesia-alumina spinel particles is 1:(0.1~10), for example, it can be 1:0.1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0109] In some embodiments, the material of the second cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles, and the mass ratio of the 2-1 mm cordierite particles to the 1.5-0.2 mm cordierite particles is 1:(0.1-10), for example, it can be 1:0.1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0110] In some embodiments, the material of the second mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles, and the mass ratio of the 2-1 mm mullite particles, the 1-0.2 mm mullite particles and the 1.5-0.2 mm mullite particles is 1:(0.3-15):(0.067-15), for example, it can be 1:0.3:0.067, 1:1:1.5, 1:3:4.5, 1:5:7.5, 1:7:9, 1:9:11, 1:11:12, 1:13:13 or 1:15:15, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0111] In some embodiments, the material of the second corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles, and the mass ratio of the 1-0 mm corundum particles to the 1-0 mm corundum particles is 1:(0.1-15), for example, it can be 1:0.1, 1:1, 1:3, 1:4, 1:7, 1:9, 1:11, 1:13 or 1:15, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0112] In some embodiments, the sealing time is more than 12 hours, for example, it can be 12 hours, 13 hours, 14 hours, 15 hours or 20 hours, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0113] In some embodiments, the compression molding pressure is 10 MPa to 40 MPa, for example, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa or 40 MPa, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0114] In some embodiments, the sintering temperature is 1200°C to 1300°C, for example, 1200°C, 1220°C, 1240°C, 1260°C, 1280°C or 1300°C, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0115] In some embodiments, the sintering time is 2 hours to 6 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, including but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0116] In some embodiments, the sintering cooling method is furnace cooling.

[0117] In another specific embodiment, the present invention provides a sagger resistant to corrosion by lithium battery materials, and the sagger is prepared by the method for recycling waste saggers described in the aforementioned specific embodiment.

[0118] Example 1

[0119] This embodiment provides a method for recycling waste saggers, and the preparation method includes:

[0120] (1) Separating the waste sagger to obtain an erosion layer and a matrix, crushing the erosion layer and the matrix respectively to obtain an erosion layer fine powder with an average particle size of 173 μm and a composition including Li, Al, Si, Co, Mn and Ni, and a matrix fine powder with an average particle size of 175 μm and a composition including Al2O3, MgO or SiO2;

[0121] (2) a first cordierite aggregate with a particle size of 2-0.2 mm, a first mullite aggregate with a particle size of 2-0.2 mm, a first corundum aggregate with a particle size of 1-0 mm, and a magnesia-alumina spinel aggregate with a particle size of 1-0 mm are mixed in a mass ratio of 1:2:1:1 to obtain a coating mixed aggregate; wherein the material of the first cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles in a mass ratio of 1:5, The material of the first mullite aggregate includes 2-1mm mullite particles, 1-0.2mm mullite particles and 1.5-0.2mm mullite particles in a mass ratio of 1:7:6, the material of the first corundum aggregate includes 1-0mm corundum particles and 1-0.5mm corundum particles in a mass ratio of 1:6, and the material of the magnesia-alumina spinel aggregate includes 1-0.5mm magnesia-alumina spinel particles and 1-0.5mm magnesia-alumina spinel particles in a mass ratio of 1:7;

[0122] Then, the coating mixed fine powder is added to the mixed aggregate in sequence, and the mass ratio of the first mullite fine powder, magnesia-alumina spinel fine powder, first corundum fine powder, first alumina fine powder, zirconia, clay and erosion layer fine powder in the coating mixed fine powder to the first cordierite aggregate in the coating mixed aggregate is 2:0.5:1:0.75:0.5:0.5:0.8:1. After stirring evenly, dextrin is added, and after stirring evenly again, water is added to obtain a coating mixture; the mass ratios of dextrin and water to the first cordierite aggregate are 0.5:1 and 0.2:1, respectively; the average particle size of the second mullite fine powder is 40 μm, the average particle size of the second corundum fine powder is 43 μm, and the average particle size of the second alumina fine powder is 45 μm.

[0123] (3) According to a mass ratio of 1:1.5:1.6, a second cordierite aggregate with a particle size of 2-0.2 mm, a second mullite aggregate with a particle size of 2-0.2 mm, and a second corundum aggregate with a particle size of 1-0 mm are mixed to obtain a bulk mixed aggregate; bulk mixed fine powder is sequentially added to the bulk mixed aggregate, wherein the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the bulk mixed aggregate is 2:1.5:0.75:0.75:1.8:1, after stirring evenly, dextrin is added, and after stirring evenly again, water is added to obtain a bulk mixed aggregate; dextrin and water are mixed with the first The mass ratios of the cordierite aggregate are 0.4:1 and 0.6:1 respectively; the material of the second cordierite aggregate includes 2-1mm cordierite particles and 1.5-0.2mm cordierite particles in a mass ratio of 1:5, the material of the second mullite aggregate includes 2-1mm mullite particles, 1-0.2mm mullite particles and 1.5-0.2mm mullite particles in a mass ratio of 1:8:6, and the material of the second corundum aggregate includes 1-0mm corundum particles and 1-0.5mm corundum particles in a mass ratio of 1:12; the average particle size of the second mullite fine powder is 43μm, the average particle size of the second corundum fine powder is 40μm, and the average particle size of the second alumina fine powder is 45μm;

[0124] (4) sealing the coating mixture and the main body mixture for 18 hours to obtain the main body aged material and the coating aged material respectively;

[0125] (5) Spreading the coating aged material on the bottom of the mold, and then pressing the main aged material at 25 MPa, and drying at 80 ° C to obtain a green body;

[0126] (6) Sintering the green body at 1300° C. for 4 h and cooling it in the furnace to obtain a sagger resistant to corrosion by lithium battery materials.

[0127] Example 2

[0128] This embodiment provides a method for recycling waste saggers, and the preparation method includes:

[0129] (1) separating the waste sagger to obtain an erosion layer and a matrix, crushing the erosion layer and the matrix respectively to obtain an erosion layer fine powder with an average particle size of 176 μm and a composition including Li, Al, Si, Co, Mn and Ni, and a matrix fine powder with an average particle size of 178 μm and a composition including Al2O3, MgO or SiO2;

[0130] (2) A first cordierite aggregate with a particle size of 2-0.2 mm, a first mullite aggregate with a particle size of 2-0.2 mm, a first corundum aggregate with a particle size of 1-0 mm, and a magnesia-alumina spinel aggregate with a particle size of 1-0 mm are mixed in a mass ratio of 1:1:0.5:0.5 to obtain a coating mixed aggregate; wherein the material of the first cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles in a mass ratio of 1:1. The material of the first mullite aggregate includes 2-1mm mullite particles, 1-0.2mm mullite particles and 1.5-0.2mm mullite particles in a mass ratio of 1:3:4, the material of the first corundum aggregate includes 1-0mm corundum particles and 1-0.5mm corundum particles in a mass ratio of 1:2, and the material of the magnesia-alumina spinel aggregate includes 1-0.5mm magnesia-alumina spinel particles and 1-0.5mm magnesia-alumina spinel particles in a mass ratio of 1:1;

[0131] Then, the coating mixed fine powder is added to the mixed aggregate in sequence, and the mass ratio of the first mullite fine powder, magnesia-alumina spinel fine powder, first corundum fine powder, first alumina fine powder, zirconia, clay and erosion layer fine powder in the coating mixed fine powder to the first cordierite aggregate in the coating mixed aggregate is 0.75:0.25:0.5:0.05:0.05:0.05:0.1:1. After stirring evenly, dextrin is added, and after stirring evenly again, water is added to obtain a coating mixture; the mass ratios of dextrin and water to the first cordierite aggregate are 0.5:1 and 0.2:1, respectively; the average particle size of the second mullite fine powder is 42 μm, the average particle size of the second corundum fine powder is 40 μm, and the average particle size of the second alumina fine powder is 1 μm.

[0132] (3) According to a mass ratio of 1:0.75:0.5, a second cordierite aggregate with a particle size of 2-0.2 mm, a second mullite aggregate with a particle size of 2-0.2 mm, and a second corundum aggregate with a particle size of 1-0 mm are mixed to obtain a bulk mixed aggregate; bulk mixed fine powder is sequentially added to the bulk mixed aggregate, wherein the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the bulk mixed aggregate is 1:0.5:0.05:0.05:0.5:1, after stirring evenly, dextrin is added, and after stirring evenly again, water is added to obtain a bulk mixed aggregate; dextrin and water are mixed with the first cordierite aggregate and the first cordierite aggregate. The mass ratios of the bluestone aggregate are 0.4:1 and 0.6:1 respectively; the material of the second cordierite aggregate includes 2-1mm cordierite particles and 1.5-0.2mm cordierite particles in a mass ratio of 1:0.5, the material of the second mullite aggregate includes 2-1mm mullite particles, 1-0.2mm mullite particles and 1.5-0.2mm mullite particles in a mass ratio of 1:1:3, and the material of the second corundum aggregate includes 1-0mm corundum particles and 1-0.5mm corundum particles in a mass ratio of 1:1.3; the average particle size of the second mullite fine powder is 45μm, the average particle size of the second corundum fine powder is 43μm, and the average particle size of the second alumina fine powder is 42μm;

[0133] (4) sealing the coating mixture and the main body mixture for 14 hours to obtain the main body aged material and the coating aged material respectively;

[0134] (5) Spreading the coating aged material on the bottom of the mold, and then pressing the main aged material under 10 MPa, and drying at 90 ° C to obtain a green body;

[0135] (6) Sintering the green body at 1200° C. for 2 h and cooling it in the furnace to obtain a sagger resistant to corrosion by lithium battery materials.

[0136] Example 3

[0137] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2, except that the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the body mixed aggregate is 1:0.5:0.05:0.05:2:1.

[0138] Example 4

[0139] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2, except that the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the body mixed aggregate is 1:0.5:0.05:0.05:2:1, and the sintering temperature of the green body is 1250°C.

[0140] Example 5

[0141] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2, except that the mass ratio of the first mullite fine powder, magnesia-alumina spinel fine powder, first corundum fine powder, first alumina fine powder, zirconia, clay and erosion layer fine powder in the coating mixed fine powder to the first cordierite aggregate in the coating mixed aggregate is 0.75:0.25:0.5:0.05:0.05:0.05:1:1.

[0142] Example 6

[0143] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2, except that the mass ratio of the first mullite fine powder, magnesia-alumina spinel fine powder, first corundum fine powder, first alumina fine powder, zirconia, clay and erosion layer fine powder in the coating mixed fine powder to the first cordierite aggregate in the coating mixed aggregate is 0.75:0.25:0.5:0.05:0.05:0.05:1:1, and the sintering temperature is 1300°C.

[0144] Example 7

[0145] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2 except that the sintering temperature is 1400°C.

[0146] Example 8

[0147] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2 except that the sintering temperature is 1100°C.

[0148] Example 9

[0149] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2, except that the mass ratio of the first mullite fine powder, magnesia-alumina spinel fine powder, first corundum fine powder, first alumina fine powder, zirconia, clay and erosion layer fine powder in the coating mixed fine powder to the first cordierite aggregate in the coating mixed aggregate is 0.75:0.25:0.5:0.05:0.05:0.05:1.5:1.

[0150] Example 10

[0151] This embodiment provides a method for recycling waste saggers. The preparation method is the same as that of Example 2, except that the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the body mixed aggregate is 1:0.5:0.05:0.05:2.5:1.

[0152] Comparative Example 1

[0153] This comparative example provides a method for preparing a sagger from waste saggers. The preparation method is the same as that of Example 2 except that no base fine powder is added to the main body mixed fine powder.

[0154] Comparative Example 2

[0155] This comparative example provides a method for preparing a sagger from waste saggers. The preparation method is the same as that of Example 2, except that the erosion layer fine powder is not added to the coating mixed fine powder.

[0156] Comparative Example 3

[0157] This comparative example provides a method for preparing a sagger from waste saggers. The preparation method is the same as that of Example 2, except that the erosion layer fine powder is not added to the coating mixed fine powder and the base fine powder is not added to the body mixed fine powder.

[0158] Performance testing:

[0159] According to the GB / T2997-2015 test standard, the apparent porosity of the saggers prepared in all the above embodiments and comparative examples was tested. The test results are shown in Table 1.

[0160] According to the GB / T3001-2017 test standard, the flexural strength of the saggers prepared in all the above embodiments and comparative examples was tested. The test results are shown in Table 1.

[0161] According to the GB / T30873-2014 test standard, the thermal shock stability of the saggers prepared in all the above examples and comparative examples was tested. The test conditions were: the saggers were heated to 1100° C. and cooled with circulating air three times. The strength retention rate before and after the test was calculated. The test results are shown in Table 1.

[0162] Table 1

[0163]

[0164]

[0165] The present invention crushes the eroded layer and matrix of a waste sagger into eroded layer fine powder and aggregate fine powder, respectively, and adds the eroded layer fine powder and aggregate fine powder, respectively, to a coating mixed fine powder and a bulk mixed fine powder to prepare a new sagger, thereby achieving efficient recycling of the waste sagger. Furthermore, according to the test results of Example 2 and Comparative Examples 1 to 3, the present invention reduces the apparent porosity of the sagger and simultaneously improves its flexural strength and thermal shock resistance after adding the eroded layer fine powder and matrix fine powder to the coating mixed fine powder and bulk mixed fine powder, thereby successfully preparing a sagger resistant to erosion by lithium battery materials.

[0166] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for recycling waste saggers, characterized in that: The method comprises: (1) Separating and crushing the erosion layer and the matrix of the waste sagger to obtain erosion layer fine powder and matrix fine powder; (2) adding coating mixed fine powder, a binder, and a solvent to the coating mixed aggregate in sequence to obtain a coating mixture; wherein the coating mixed fine powder includes the erosion layer fine powder; (3) adding bulk mixed fine powder, a binder, and a solvent to the bulk mixed aggregate in sequence to obtain a bulk mixed material; the bulk mixed fine powder includes the matrix fine powder; (4) sealing the coating mixture and the main body mixture to obtain coating stale material and main body stale material respectively; (5) spreading the coating stale material on the bottom of the mold, then filling the body stale material, pressing and forming, and drying to obtain a green body; (6) sintering the green body to obtain a sagger resistant to erosion by lithium battery materials; The order of steps (2) and (3) is not critical.

2. The method according to claim 1, wherein The coating mixed aggregate includes a first cordierite aggregate, a first mullite aggregate, a first corundum aggregate and a magnesia-alumina spinel aggregate; Preferably, the particle size of the first cordierite aggregate is 2-0.2 mm; Preferably, the particle size of the first mullite aggregate is 2-0.2 mm; Preferably, the particle size of the first corundum aggregate is 1-0 mm; Preferably, the particle size of the magnesia-alumina spinel aggregate is 1-0 mm; Preferably, in the coating mixed aggregate, the mass ratio of the first cordierite aggregate, the first mullite aggregate, the first corundum aggregate and the magnesia-alumina spinel aggregate is 1:(1-3):(0.5-2):(0.5-2); Preferably, the coating mixed fine powder includes a first mullite fine powder, a magnesia-alumina spinel fine powder, a first corundum fine powder, a first alumina fine powder, zirconium oxide, a first clay and the erosion layer fine powder; Preferably, in the coating mixed fine powder, the average particle size of the first mullite fine powder, the magnesia alumina spinel fine powder, the first corundum fine powder, the first alumina fine powder and the zirconia fine powder is independently 45 μm or less; Preferably, in the coating mixed fine powder, the mass ratio of the first mullite fine powder, magnesia-alumina spinel fine powder, the first corundum fine powder, the first alumina fine powder, zirconia, clay, erosion layer fine powder and the first cordierite aggregate in the coating mixed aggregate is (0.75-3):(0.25-1):(0.5-2):(0.05-1):(0.05-1):(0.05-1):(0.05-1):

1.

3. The method according to claim 1 or 2, wherein: The bulk mixed aggregate includes a second cordierite aggregate, a second mullite aggregate and a second corundum aggregate; Preferably, the particle size of the second cordierite aggregate is 2-0.2 mm; Preferably, the particle size of the second mullite aggregate is 2-0.2 mm; Preferably, the particle size of the second corundum aggregate is 1-0 mm; Preferably, in the bulk mixed aggregate, the mass ratio of the second cordierite aggregate, the second mullite aggregate, and the second corundum aggregate is 1:(0.75-3):(0.5-2); Preferably, the bulk mixed fine powder includes a second mullite fine powder, a second corundum fine powder, a second alumina fine powder, a second clay and the matrix fine powder; Preferably, the average particle size of the second mullite fine powder, the second corundum fine powder and the second alumina fine powder are each independently less than 45 μm; Preferably, in the bulk mixed fine powder, the mass ratio of the second mullite fine powder, the second corundum fine powder, the second alumina fine powder, the second clay, the matrix fine powder and the second cordierite aggregate in the bulk mixed aggregate is (1-3):(0.5-2):(0.05-1):(0.05-1):(0.5-2):

1.

4. The method according to any one of claims 1 to 3, wherein: The element composition of the erosion layer fine powder includes Li and M, and the M includes any one or a combination of at least two of Al, Si, Co, Mn or Ni; Preferably, the material of the matrix fine powder includes one or a combination of at least two of Al2O3, MgO or SiO2.

5. The method according to any one of claims 1 to 4, characterized in that The average particle size of the eroded layer fine powder and the matrix fine powder is independently 180 μm or less.

6. The method according to any one of claims 2 to 5, wherein: The material of the first cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles; Preferably, in the first cordierite aggregate, the mass ratio of 2-1 mm cordierite particles to 1.5-0.2 mm cordierite particles is 1:(0.1-10); Preferably, the material of the first mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles; Preferably, in the first mullite aggregate, the mass ratio of 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles is 1:(0.5-15):(0.1-10); Preferably, the material of the first corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles; Preferably, in the first corundum aggregate, the mass ratio of 1-0 mm corundum particles to 1-0.5 mm corundum particles is 1:(0.1-10); Preferably, the material of the magnesia-alumina spinel aggregate includes 1-0 mm magnesia-alumina spinel particles and 1-0.5 mm magnesia-alumina spinel particles; Preferably, in the magnesia-alumina spinel aggregate, the mass ratio of 1-0 mm magnesia-alumina spinel particles to 1-0.5 mm magnesia-alumina spinel particles is 1:(0.1-10).

7. The method according to any one of claims 2 to 6, wherein: The material of the second cordierite aggregate includes 2-1 mm cordierite particles and 1.5-0.2 mm cordierite particles; Preferably, in the second cordierite aggregate, the mass ratio of 2-1 mm cordierite particles to 1.5-0.2 mm cordierite particles is 1:(0.1-10); Preferably, the material of the second mullite aggregate includes 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles; Preferably, in the second mullite aggregate, the mass ratio of 2-1 mm mullite particles, 1-0.2 mm mullite particles and 1.5-0.2 mm mullite particles is 1:(0.3-15):(0.067-15); Preferably, the material of the second corundum aggregate includes 1-0 mm corundum particles and 1-0.5 mm corundum particles; Preferably, in the second corundum aggregate, the mass ratio of 1-0 mm corundum particles to 1-0 mm corundum particles is 1:(0.1-15).

8. The method according to any one of claims 1 to 7, characterized in that The sealing time is more than 12 hours; Preferably, the compression molding pressure is 10 MPa to 40 MPa.

9. The method according to claim 1, wherein The sintering temperature is 1200° C. to 1300° C.; Preferably, the sintering time is 2h to 6h; Preferably, the cooling method of the sintering is furnace cooling.

10. A sagger resistant to corrosion by lithium battery materials, characterized in that: The sagger is prepared by the method for recycling waste saggers according to any one of claims 1 to 9.

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