A diversified recovery method of negative electrode material of waste power lithium battery

Abstract

The present application relates to a kind of diversified recovery methods of waste power lithium battery negative electrode material, comprising the following steps: (1) waste lithium electronic negative electrode material is carried out crushing screening pretreatment, and the particle size interval of 3 kinds of materials after crushing screening is respectively:<0.1mm, 0.1-0.6mm, >0.6mm, wherein 0.1-0.6mm is the leading particle size, and the proportion is >65%;(2) the extremely fine powder of particle size <0.1mm obtained in step (1) is carried out ball milling treatment, and obtains ground graphite;(3) the leading particle size of particle size 0.1-0.6mm is sorted and handled, and the material is sequentially passed through fluidized bed sorting, flotation, magnetic separation process, and finally sorted graphite and sorted copper powder are obtained;(4) the coarse particle material is carried out high-voltage current impact stripping graphite treatment, and impact stripping graphite and copper foil are obtained.The diversified recovery method of negative electrode material in the present application adopts crushing, screening, ball milling and other processes, without water solution and acid solution, to ensure the purity of the recovered product.

Description

TECHNICAL FIELD

[0001] The application relates to a method for recycling negative electrode materials of waste power lithium batteries, in particular to a method for recycling graphite of negative electrode materials of waste power lithium batteries. BACKGROUND

[0002] The existing waste power lithium battery recycling technology mainly involves two categories: whole-process treatment of waste power lithium batteries and recovery of multiple-component metals in positive electrode sheets, and there are few records of diversified recovery methods for negative electrode materials of waste power lithium batteries. A patent application with the title of "a combined treatment method for waste lithium ion battery black powder" and the application number of "202010896444.3" is disclosed in the Chinese patent bulletin. The disclosed treatment method is to treat the negative electrode material by water immersion and acid immersion. The water solution immersion stripping black powder (graphite) process is relatively simple, but there are problems such as incomplete stripping of large pieces of curled copper foil, serious loss of black powder (graphite), and the like. The direct shearing type crushing and hammer breaking have a very high fine powder content and are easy to introduce external impurities and have low purity. The separation efficiency of the mixed fine components in the separation process is low, and there is also a problem of loss of large pieces of curled copper foil black powder (graphite). How to position the product according to market demand, take multiple channels as the goal, and develop a diversified recovery method accordingly will effectively improve the recovery efficiency of waste power lithium negative electrode sheets. SUMMARY

[0003] The application aims to provide a diversified recovery method for negative electrode materials of waste power lithium batteries.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the application adopts a diversified recovery method for negative electrode materials of waste power lithium batteries, which comprises the following steps: (1) crushing and screening pretreatment of waste lithium electronic negative electrode materials, and the particle size intervals of the three materials after crushing and screening are < a first threshold value, a first threshold value to a second threshold value, and > a second threshold value; (2) ball milling treatment of the extremely fine powder with a particle size < the first threshold value obtained in step (1) to obtain ground graphite.

[0005] In step (2), the material with a particle size < the first threshold value is extremely fine powder, which enters the ball mill for ball milling to modify the surface sphericity and finally becomes ground graphite; the ball milling index of the extremely fine powder is: D50 = 6-15 mu m, fixed carbon content >= 99.0%, and tap density >= 0.95 g / cm 3 .

[0006] The technical scheme of the present application also adopts a diversified recovery method of waste power lithium battery negative electrode material, comprising the following steps: (1) crushing and screening pretreatment is performed on the waste lithium electronic negative electrode material, and after crushing and screening, the particle size intervals of the three materials are:< first threshold, first threshold to second threshold, > second threshold; (2) the main particle size of the first threshold to the second threshold is selected and treated, and the material is sequentially subjected to fluidized bed separation, flotation, and magnetic separation process, and finally the selected graphite and selected copper powder are obtained.

[0007] The fluidized bed separation condition in step (2) is: flow rate <0.8 m / s; the flotation separation condition is: lime and water glass are used as adjusting agents, kerosene is used as a collector, and secondary octanol is used as a foaming agent, and the roughing time is 2-6 min, and the cleaning and scavenging time is 2-6 min. 3

[0008] The technical scheme of the present application also adopts a diversified recovery method of waste power lithium battery negative electrode material, comprising the following steps: (1) crushing and screening pretreatment is performed on the waste lithium electronic negative electrode material, and after crushing and screening, the particle size intervals of the three materials are:< first threshold, first threshold to second threshold, > second threshold; (2) the main particle size of the first threshold to the second threshold is selected and treated, and the material is sequentially subjected to fluidized bed separation, flotation, and magnetic separation process, and finally the selected graphite and selected copper powder are obtained.

[0009] In step (2), the coarse particle size material is a material with a particle size > second threshold.

[0010] The technical scheme of the present application also adopts a diversified recovery method of waste power lithium battery negative electrode material, comprising the following steps: (1) crushing and screening pretreatment is performed on the waste lithium electronic negative electrode material, and after crushing and screening, the particle size intervals of the three materials are:< first threshold, first threshold to second threshold, > second threshold; (2) the main particle size of the first threshold to the second threshold is selected and treated, and the material is sequentially subjected to fluidized bed separation, flotation, and magnetic separation process, and finally the selected graphite and selected copper powder are obtained.

[0011] In step (4), in the high-voltage current impact graphite stripping treatment, the experimental voltage is 100 kV, the pressure is 1000 Mpa, and the action time is 10-20 min.

[0012] ​In step (1), the pretreatment of the waste lithium electronic negative electrode material is specifically: crushing the waste lithium electronic negative electrode material, and performing secondary screening on the crushed material to obtain three kinds of materials; the waste lithium electronic negative electrode material is fed into the crusher as a whole, the shear force is > 120 MPa, the particle size of the output material is < 0.6 mm, and the proportion is 90%, the secondary screening aperture sizes are 0.6 mm and 0.1 mm, and the particle size intervals of the three kinds of materials after crushing and screening are < a first threshold value, a first threshold value to a second threshold value, and > the second threshold value, wherein the first threshold value to the second threshold value is the main particle size, and the proportion is > 65%.

[0013] The first threshold value is 0.1 mm, and the second threshold value is 0.6 mm.

[0014] The recycling method of the present application has the following beneficial effects: (1) The recycling method of the present application aims at the technical problems of the current fine powder affecting the sorting of the waste power lithium battery negative electrode material, the high content of black powder impurities, and the serious loss of black powder carried by the large piece of curled copper foil. The recycling method of the negative electrode material adopts crushing, screening, ball milling and other processes, without water and acid dissolution, which ensures the purity of the recycled product. (2) The present application focuses on the implementation of diversified products and technologies, and can ensure the collection of three kinds of graphite products with different performance indexes after one-time full-process implementation. The performance indexes are different but have market application prospects, and the "early collection" is realized. The adaptability of the single stripping recovery and crushing recovery technology is stronger. (3) For the crushing-fluidized bed sorting treatment, the functions of the first mismatch area and the second mismatch area are emphasized, which can ensure high graphite recovery quality compared with the existing similar technologies in the market. At the same time, the designed fluidized bed-flotation-magnetic separation progressive sorting technology can effectively reduce the graphite impurity content and achieve high purity index. (4) The problem of loss of graphite carried by the curled copper foil can be solved by the coupling effect of high-frequency oscillation and high-voltage electric shock to strip the graphite, which improves the recovery rate of the graphite product. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the full-process processing route of the present application;

[0016] In the figure: Pretreatment of waste lithium battery negative electrode material; Extremely fine powder ball milling treatment; Main particle size sorting treatment; Coarse particle size high-voltage current shock graphite stripping treatment. DETAILED DESCRIPTION

[0017] Example 1

[0018] The diversified recycling method of the negative electrode material of the waste power lithium battery of the embodiment comprises the following steps: (1) the waste lithium electronic negative electrode material is pretreated by crushing and screening, and the particle size intervals of the three materials after crushing and screening are <0.1mm, 0.1-0.6mm and >0.6mm, wherein the 0.1-0.6mm is the dominant particle size, and the proportion is >65%; (2) the extremely fine powder with a particle size <0.1mm obtained in step (1) is treated by ball milling to obtain ground graphite.

[0019] Embodiment 2

[0020] The diversified recycling method of the negative electrode material of the waste power lithium battery of the embodiment comprises the following steps: (1) the waste lithium electronic negative electrode material is pretreated by crushing and screening, and the particle size intervals of the three materials after crushing and screening are <0.1mm, 0.1-0.6mm and >0.6mm, wherein the 0.1-0.6mm is the dominant particle size, and the proportion is >65%; (2) the dominant particle size with a particle size of 0.1-0.6mm is sorted, and the material is sequentially subjected to fluidized bed sorting, flotation and magnetic separation processes, and finally sorted graphite and sorted copper powder are obtained, the fluidized bed sorting conditions are: flow rate is 0.6m / s; the flotation sorting conditions are: lime and water glass are used as adjusting agents, kerosene is used as a collector, and secondary octanol is used as a foaming agent, roughing time is 3min, and cleaning and scavenging time is 3min. 3

[0021] Embodiment 3

[0022] The diversified recycling method of the negative electrode material of the waste power lithium battery of the embodiment comprises the following steps:

[0023] (1) the waste lithium electronic negative electrode material is pretreated by crushing and screening, and the particle size intervals of the three materials after crushing and screening are <0.1mm, 0.1-0.6mm and >0.6mm, wherein the 0.1-0.6mm is the dominant particle size, and the proportion is >65%; (2) the coarse particle size material is subjected to high-voltage current impact graphite stripping treatment to obtain impact stripped graphite and copper foil, in the high-voltage current impact graphite stripping treatment, the experimental voltage is 100kV, the pressure is 1000Mpa, and the action time is 15min.

[0024] Embodiment 4

[0025] The diversified recycling method of the negative electrode material of the waste power lithium battery of the embodiment comprises the following steps: Figure 1 ​As shown, the method comprises the following steps: (1) pre-treating the waste lithium electronic negative electrode material 1 by crushing and screening, specifically: crushing the waste lithium electronic negative electrode material, and secondarily screening the crushed material to obtain three kinds of materials; feeding the waste lithium electronic negative electrode material into the crusher as a whole piece, the shear force being > 120 MPa, the particle size of the discharged material being < 0.6 mm, the proportion being 90%, the second screening aperture sizes being 0.6 mm and 0.1 mm, and the particle size intervals of the three kinds of materials after crushing and screening being < 0.1 mm, 0.1-0.6 mm and > 0.6 mm, respectively, wherein the 0.1-0.6 mm is the dominant particle size, and the proportion is > 65%; (2) the material with a particle size < 0.1 mm in step (1) is extremely fine powder, which is ball milled in a ball mill to modify the surface sphericity, and finally becomes the ground graphite 9; the ball milling index of the extremely fine powder is: D50 = 6-15 μm, the fixed carbon content is ≥ 99.0%, and the tap density is ≥ 0.95 g / cm 3 ; (3) sorting the dominant particle size of 0.1-0.6 mm, sequentially passing the material through the fluidized bed sorting, flotation and magnetic separation processes, and finally obtaining the sorted graphite 10 and sorted copper powder; the fluidized bed sorting conditions are: the flow rate is 0.6 m 3 / s; the flotation sorting conditions are: using lime and water glass as the adjusting agent, kerosene as the collector, and sec-octyl alcohol as the foaming agent, the roughing time is 4 min, and the cleaning and scavenging time is 4 min; (4) performing high-voltage current impact stripping graphite treatment on the coarse particle size material, the coarse particle size material being the material with a particle size > 0.6 mm, to obtain the impact stripped graphite 11 and copper foil, and in the high-voltage current impact stripping graphite treatment, the experimental voltage is 100 kV, the pressure is 1000 Mpa, and the action time is 15 min.

[0026] The performance indicators of the graphite product obtained by the recycling method of the embodiment are shown in Table 1.

[0027] Table 1

[0028]

Claims

1. A method for diversified recycling of negative materials of waste power lithium batteries, characterized in that: The method comprises the following steps: (1) performing crushing and screening pretreatment on the waste lithium electronic negative electrode material, and the particle size intervals of the three materials after crushing and screening are:<first threshold value, first threshold value to second threshold value, > second threshold value; (2) performing ball milling treatment on the extremely fine powder with a particle size of < the first threshold value to obtain ground graphite; the pretreatment on the waste lithium electronic negative electrode material is specifically: crushing the waste lithium electronic negative electrode material, and performing secondary screening on the crushed material to obtain three materials; the waste lithium electronic negative electrode material is fed into the crusher in the form of a whole piece, the shear force is > 120 MPa, the discharge particle size is < 0.6 mm, the proportion is 90%, the secondary screening aperture sizes are 0.6 mm and 0.1 mm, and the particle size intervals of the three materials after crushing and screening are:<first threshold value, first threshold value to second threshold value, > second threshold value, wherein the first threshold value to the second threshold value is the dominant particle size, and the proportion is > 65%.

2. The method of claim 1, wherein the method comprises: In step (2), the material particle size < first threshold value is superfine powder, the material enters the ball mill for ball milling to modify the surface sphericity, and finally becomes the ground graphite; the superfine powder ball milling index is: D50=6-15 μm, fixed carbon content ≥99.0%, and tap density ≥0.95 g / cm 3 .

3. A method for diversified recycling of negative materials of waste power lithium batteries, characterized in that: The method comprises the following steps: (1) performing crushing and screening pretreatment on the waste lithium electronic negative electrode material, and the particle size intervals of the three materials after crushing and screening are:<first threshold value, first threshold value to second threshold value, > second threshold value; (2) performing sorting treatment on the dominant particle size with a particle size of the first threshold value to the second threshold value, and sequentially passing the material through the fluidized bed sorting, flotation and magnetic separation processes to finally obtain sorted graphite and sorted copper powder; the pretreatment on the waste lithium electronic negative electrode material is specifically: crushing the waste lithium electronic negative electrode material, and performing secondary screening on the crushed material to obtain three materials; the waste lithium electronic negative electrode material is fed into the crusher in the form of a whole piece, the shear force is > 120 MPa, the discharge particle size is < 0.6 mm, the proportion is 90%, the secondary screening aperture sizes are 0.6 mm and 0.1 mm, and the particle size intervals of the three materials after crushing and screening are:<first threshold value, first threshold value to second threshold value, > second threshold value, wherein the first threshold value to the second threshold value is the dominant particle size, and the proportion is > 65%.

4. The method of claim 3, wherein the method further comprises: Fluidized bed separation conditions in step (2): flow rate <0.8 m / s 3 Floatation separation conditions: lime and water glass were used as adjusting agents, kerosene as collector, sec-octyl alcohol as frother, roughing time 2-6 min, cleaning and scavenging time 2-6 min. ​ 5. A method for diversified recycling of negative materials of waste power lithium batteries, characterized in that: The method comprises the following steps: (1) performing crushing and screening pretreatment on the waste lithium electronic negative electrode material, and the particle size intervals of the three materials after crushing and screening are:<first threshold value, first threshold value to second threshold value, > second threshold value; (2) performing high-voltage current impact stripping graphite treatment on the coarse particle size material to obtain impact stripping graphite and copper foil; the pretreatment on the waste lithium electronic negative electrode material is specifically: crushing the waste lithium electronic negative electrode material, and performing secondary screening on the crushed material to obtain three materials; the waste lithium electronic negative electrode material is fed into the crusher in the form of a whole piece, the shear force is > 120 MPa, the discharge particle size is < 0.6 mm, the proportion is 90%, the secondary screening aperture sizes are 0.6 mm and 0.1 mm, and the particle size intervals of the three materials after crushing and screening are:<first threshold value, first threshold value to second threshold value, > second threshold value, wherein the first threshold value to the second threshold value is the dominant particle size, and the proportion is > 65%.

6. The method of claim 5, wherein the method further comprises: In step (2), the coarse particle size material is the material with a particle size of > the second threshold value.

7. A method for diversified recycling of negative materials of waste power lithium batteries, characterized in that: The method comprises the following steps: (1) the waste lithium electronic negative electrode material is pretreated by crushing and screening, and the particle size intervals of the three materials after crushing and screening are < a first threshold value, a first threshold value to a second threshold value, and > the second threshold value; (2) the extremely fine powder with a particle size < the first threshold value obtained in step (1) is treated by ball milling to obtain ground graphite; (3) the main particle size fraction with a particle size of the first threshold value to the second threshold value is treated by screening, and the material is sequentially subjected to fluidized bed separation, flotation and magnetic separation processes, and finally, the separated graphite and separated copper powder are obtained; and (4) the coarse particle size material is treated by high-voltage current impact stripping graphite to obtain impact stripping graphite and copper foil.

8. The method of claim 7, wherein the method further comprises: In step (4), in the high-voltage current impact stripping graphite treatment, the experimental voltage is 100 kV, the pressure is 1000 Mpa, and the action time is 10-20 min.

9. The method according to claim 7 or 8, wherein: In step (1), the pretreatment of the waste lithium electronic negative electrode material is specifically as follows: the waste lithium electronic negative electrode material is crushed, and the crushed material is subjected to secondary screening to obtain three materials; the waste lithium electronic negative electrode material is fed into the crusher as a whole, the shear force is > 120 MPa, the discharge particle size is < 0.6 mm, the proportion is 90%, the secondary screening aperture sizes are 0.6 mm and 0.1 mm, and the particle size intervals of the three materials after crushing and screening are < a first threshold value, a first threshold value to a second threshold value, and > the second threshold value, wherein the first threshold value to the second threshold value is the main particle size fraction, and the proportion is > 65%.

10. The method of claim 7 or 8, wherein the method further comprises: The first threshold value is 0.1 mm, and the second threshold value is 0.6 mm.

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