METHOD FOR RECOVERING ALUMINUM RESIDUE WITH CONTROLLED PARTICLE SIZE, AND USE THEREOF

Abstract

The present disclosure belongs to the technical field of battery recycling, and discloses a method for recovering an aluminum residue with a controlled particle size, and use thereof. The method includes the following steps: crushing and sieving a positive electrode sheet of a waste power battery, then, crushing at 198 C. to 196 C. with addition of liquid nitrogen to obtain a granular material; roasting, cooling, and grinding the granular material, adding water, shaking, settling into layers, and separating the layers to obtain a positive electrode active powder layer, a transition layer, and an aluminum residue particle layer; and shaking the aluminum residue particle layer and the transition layer for a second time, settling into layers, and collecting aluminum residue particles and a positive electrode active powder.

Claims

1. A method for recovering an aluminum residue with a controlled particle size, comprising the following steps: (1) crushing and sieving a positive electrode sheet of a waste power battery, then, crushing at 198 C. to 196 C. with addition of liquid nitrogen to obtain a granular material; (2) roasting the granular material, collecting a gaseous binder produced from the roasting with an alkaline solution, cooling, and grinding a residue to obtain a waste positive electrode sheet powder; (3) adding water to the waste positive electrode sheet powder, shaking, settling into layers, and separating the layers to obtain a positive electrode active powder layer, a transition layer, and an aluminum residue particle layer; and (4) shaking the aluminum residue particle layer and the transition layer for a second time, settling into layers, and collecting aluminum residue particles and a positive electrode active powder, in step (1), the granular material has a particle size of 0.01 m to 500 m; in step (2), the gaseous binder is polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); in step (2), a grinder used in the grinding has a treatment capacity of <100 kg/h and a rotational speed of 120 rpm to 180 rpm; in steps (3) and (4), during shaking, the waste positive electrode sheet powder are kept immersed in water in a container; and the water is deionized water; steps (3) and (4) are repeated 1 to 10 times until the aluminum residue particles and the positive electrode active powder in the particles are completely separated and collected.

2. The method according to claim 1, wherein in step (1), the liquid nitrogen is added at an amount of 5% to 30% of a mass of the positive electrode sheet of the waste power battery.

3. The method according to claim 1, wherein in step (2), the roasting is conducted in an inert gas atmosphere; and an inert gas of the inert gas atmosphere is one from the group consisting of He, Ne, and Ar.

4. The method according to claim 1, wherein in step (2), the roasting is conducted at 350 C. to 500 C. for 30 min to 60 min.

5. The method according to claim 1, wherein the alkaline solution is at least one from the group consisting of Mg(OH).sub.2, NaOH, and Ca(OH).sub.2.

6. The method according to claim 1, wherein in steps (3) and (4), a shaker used in the shaking has a shaking frequency of 5 Hz to 20 Hz and a shaking amplitude of 0.5 cm to 2 cm, and the shaking is conducted for 5 min to 10 min.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0032] The sole figure is a flowchart of the method for recovering an aluminum residue with a controlled particle size according to an example of the present disclosure.

DETAILED DESCRIPTION

[0033] The concepts and technical effects of the present disclosure are clearly and completely described below in conjunction with examples, so as to allow the objectives, features and effects of the present disclosure to be fully understood. Apparently, the described examples are merely some rather than all of the examples of the present disclosure. All other examples obtained by those skilled in the art based on the examples of the present disclosure without creative efforts should fall within the protection scope of the present disclosure.

Example 1

[0034] A method for recovering an aluminum residue with a controlled particle size was provided, including the following specific steps: [0035] (1) preparation of waste positive electrode sheet particles: a waste positive electrode sheet produced in a power battery production process was recovered, and then coarsely crushed mechanically and sieved; and 9% liquid nitrogen was added, and then fine crushing was conducted to obtain waste positive electrode sheet particles with impurities, which had a particle size of 0.01 m to 500 m; [0036] (2) roasting: 113 kg of the waste positive electrode sheet particles was placed in an electric resistance furnace; the electric resistance furnace was filled with He, a temperature of the electric resistance furnace was increased and controlled at 360 C., and the roasting was stably conducted for 55 min, where a heating rate for the electric resistance furnace was controlled at 15 C./min; and a gas produced during the roasting was collected through a Ca(OH).sub.2 alkaline solution; [0037] (3) cooling and grinding: on the basis of step (2), the waste positive electrode sheet particles in the electric resistance furnace were cooled to room temperature, and then cooled waste positive electrode sheet particles were ground on a disc grinder for about 1.5 h to obtain a waste positive electrode sheet powder, where the grinder had a discharge amount of about 80 kg/h and a rotational speed of 160 rpm; [0038] (4) first shaking: on the basis of step (3), 30 kg of the waste positive electrode sheet powder was transferred into a stainless steel cuboid container, and deionized water was added to just immerse the waste positive electrode sheet powder in the container; and the cuboid container was fixed on a horizontal shaker and shaken for 6 min to obtain a positive electrode active powder layer, a transition layer, and an aluminum residue particle layer, where the horizontal shaker had a shaking frequency of 8 Hz and a shaking amplitude of 1.0 cm; [0039] (5) second shaking: on the basis of step (4), the positive electrode active powder layer in the container was transferred into another container, and the aluminum residue particle layer and the transition layer were collected and transferred to a clean stainless steel cuboid container, and shaken for 6 min to obtain an aluminum residue particle layer and a positive electrode active powder layer, where a shaker had a shaking frequency of 8 Hz and a shaking amplitude of 1.0 cm, and during shaking, the waste positive electrode sheet powder was kept immersed in deionized water in the container; [0040] (6) steps (4) and (5) were repeated 3 times such that the aluminum residue particles and the positive electrode active powder in 118 kg of the waste positive electrode sheet particles were completely recovered.

Example 2

[0041] A method for recovering an aluminum residue with a controlled particle size was provided, including the following specific steps: [0042] (1) preparation of waste positive electrode sheet particles: a waste positive electrode sheet produced in a power battery production process was recovered, and then coarsely crushed mechanically and sieved; and 15% liquid nitrogen was added, and then fine crushing was conducted to obtain a granular material with a particle size of 0.01 m to 500 m; [0043] (2) roasting: 261 kg of the granular material was placed in an electric resistance furnace; the electric resistance furnace was filled with He, a temperature of the electric resistance furnace was increased and controlled at 420 C., and the roasting was stably conducted for 40 min, where a heating rate for the electric resistance furnace was controlled at 15 C./min; and a gas produced during the roasting was collected through a Ca(OH).sub.2 alkaline solution; [0044] (3) cooling and grinding: on the basis of step (2), the waste positive electrode sheet particles in the electric resistance furnace were cooled to room temperature, and then cooled waste positive electrode sheet particles were ground on a disc grinder for about 1.5 h to obtain a waste positive electrode sheet powder, where the grinder had a discharge amount of about 80 kg/h and a rotational speed of 160 rpm; [0045] (4) first shaking: on the basis of step (3), 30 kg of the waste positive electrode sheet powder was transferred into a stainless steel cuboid container, and deionized water was added to just immerse the waste positive electrode sheet powder in the container; and the cuboid container was fixed on a horizontal shaker and shaken for 6 min to obtain a positive electrode active powder layer, a transition layer, and an aluminum residue particle layer, where the horizontal shaker had a shaking frequency of 8 Hz and a shaking amplitude of 1.0 cm; [0046] (5) second shaking: on the basis of step (4), the positive electrode active powder layer in the container was transferred into another container, and the aluminum residue particle layer and the transition layer were collected and transferred to a clean stainless steel cuboid container, and shaken for 6 min to obtain an aluminum residue particle layer and a positive electrode active powder layer, where a shaker had a shaking frequency of 8 Hz and a shaking amplitude of 1.0 cm, and during shaking, the waste positive electrode sheet particles were kept immersed in deionized water in the container; [0047] (6) steps (4) and (5) were repeated 3 times such that the aluminum residue particles and the positive electrode active powder in 118 kg of the waste positive electrode sheet particles were completely recovered.

Example 3

[0048] A method for recovering an aluminum residue with a controlled particle size was provided, including the following specific steps: [0049] (1) preparation of waste positive electrode sheet particles: a waste positive electrode sheet produced in a power battery production process was recovered, and then coarsely crushed mechanically and sieved; and 22% liquid nitrogen was added, and then fine crushing was conducted to obtain a granular material with a particle size of 0.01 m to 500 m; [0050] (2) roasting: 387 kg of the granular material was placed in an electric resistance furnace; the electric resistance furnace was filled with He, a temperature of the electric resistance furnace was increased and controlled at 460 C., and the roasting was stably conducted for 35 min, where a heating rate for the electric resistance furnace was controlled at 18 C./min; and a gas produced during the roasting was collected through a Mg(OH).sub.2 alkaline solution; [0051] (3) cooling and grinding: on the basis of step (2), the waste positive electrode sheet particles in the electric resistance furnace were cooled to room temperature, and then cooled waste positive electrode sheet particles were ground on a disc grinder for about 4.8 h to obtain a waste positive electrode sheet powder, where the grinder had a treatment capacity of about 80 kg/h and a rotational speed of 120 rpm; [0052] (4) first shaking: about 80 kg of the waste positive electrode sheet powder was transferred into a stainless steel cuboid container, and deionized water was added to just immerse the waste positive electrode sheet powder in the container; and the cuboid container was fixed on a horizontal shaker and shaken for 10 min to obtain a positive electrode active powder layer, a transition layer, and an aluminum residue particle layer, where the horizontal shaker had a shaking frequency of 15 Hz and a shaking amplitude of 0.5 cm; [0053] (5) second shaking: on the basis of step (4), the positive electrode active powder layer in the container was transferred into another container, and the aluminum residue particle layer and the transition layer were collected and transferred to a clean stainless steel cuboid container, and shaken for 10 min to obtain an aluminum residue particle layer and a positive electrode active powder layer, where a shaker had a shaking frequency of 15 Hz and a shaking amplitude of 0.5 cm, and during shaking, the waste positive electrode sheet particles were kept immersed in deionized water in the container; [0054] (6) steps (4) and (5) were repeated 4 times such that the aluminum residue particles and the positive electrode active powder in 387 kg of the waste positive electrode sheet particles were completely recovered.

Comparative Example 1

[0055] A method for recovering an aluminum residue was provided, including the following specific steps:

[0056] This comparative example was different from Example 1 in that the shaking in steps (4) and (5) was not conducted, and the waste positive electrode sheet particles were directly ground and sieved to obtain a positive electrode active powder and aluminum residue particles.

Comparative Example 2

[0057] A method for recovering an aluminum residue with a controlled particle size was provided, including the following specific steps:

[0058] This comparative example was different from Example 1 in that, in step (1), the operation of adding liquid nitrogen to conduct fine crushing was not conducted.

[0059] Comparative analysis of Examples 1, 2, and 3 with the comparative examples:

[0060] Table 1 shows the mass percentages of aluminum residue in the positive electrode active powders recovered in Examples 1, 2, and 3 and Comparative Examples 1 and 2 and the aluminum residue particle size distribution percentages in 0 m to 10 m, 10 m to 50 m, 50 m to 100 m, and 100 m to 500 m. In Comparative Examples 1 and 2, liquid nitrogen and shaking treatments were not adopted, and only sieving was conducted with a conventional mesh screen to obtain a positive electrode active powder and aluminum residue particles. Mass percentage of aluminum residue in positive electrode active powder=mass of aluminum residue in a recovered positive electrode active powder/mass of the recovered positive electrode active powder*100%. Aluminum in the positive electrode active powder was determined by flame atomic absorption spectrometry (FAAS), and a particle size of the aluminum residue was determined with a laser particle size analyzer.

[0061] It can be seen from Table 1 that, compared with that in Comparative Examples 1 and 2, the positive electrode active powders prepared in Examples 1, 2, and 3 had extremely-small aluminum residue mass percentages (0.55%, 0.71%, and 0.42%, respectively), indirectly proving that a recovery rate of aluminum residue after the shaking was very high; in Examples 1, 2, and 3, the aluminum residue particle size distribution percentages in 0 m to 50 m were only of 7.86%, 6.31%, and 9.43%, respectively, but in Comparative Examples 1 and 2, the aluminum residue particle size distribution percentages in 0 m to 50 m were up to 13.53% and 19.75%, respectively; in Examples 1, 2, and 3, the aluminum residue particle size distribution percentages in 100 m to 500 m were of 73.88%, 76.82%, and 73.89% respectively (the largest), which were 23.52%, 26.46%, and 23.53% higher than the average aluminum residue particle size distribution percentages of Comparative Examples 1 and 2 in 100 m to 500 m, respectively; and compared with the comparative examples, in Examples 1, 2, and 3, the aluminum residue particle size distribution percentages in 100 m to 500 m were higher, indicating that the particle size of an aluminum residue was effectively controlled to improve the recovery efficiency of an aluminum residue.

TABLE-US-00001 TABLE 1 Aluminum residue mass percentages in the positive electrode active powders and aluminum residue particle size distribution percentages in different ranges Aluminum residue mass percentage Aluminum residue particle size distribution in positive percentages in different ranges (%) Treatment electrode active 0 m to 10 m to 50 m to 100 m to group powder (%) 10 m 50 m 100 m 500 m Example 1 0.55 0.14 7.72 18.26 73.88 Example 2 0.71 0.07 6.24 16.87 76.82 Example 3 0.42 0.06 9.37 16.68 73.89 K1 13.87 0.19 13.34 27.36 59.11 K2 17.55 0.74 19.01 38.64 41.61

[0062] The sole figure is a flowchart of the method for recovering an aluminum residue with a controlled particle size according to an example of the present disclosure, and it can be seen from the figure that, in the preparation of waste positive electrode sheet particles from a waste positive electrode sheet, liquid nitrogen is added to conduct fine crushing; and then the waste positive electrode sheet particles are subjected to roasting, grinding, two times of shaking for stratification to obtain an aluminum residue and a positive electrode active powder.

[0063] The examples of present disclosure are described in detail with reference to the accompanying drawings, but the present disclosure is not limited to the above examples. Within the scope of knowledge possessed by those of ordinary skill in the technical field, various changes can also be made without departing from the purpose of the present disclosure. In addition, the examples in the present disclosure or features in the examples may be combined with each other in a non-conflicting situation.