Washing and separating device and process for waste battery recovery leaching residues

Abstract

The invention discloses a washing and separating device and process for waste battery recovery leaching residues, the device comprises n washing and settling units connected in sequence, each washing and settling unit comprises a washing assembly and a settling assembly, in the same washing and settling unit, a material outlet of the washing assembly is communicated with a material inlet of the settling assembly; the solid outlet of the settling assembly of the previous washing and settling unit is communicated with the material inlet of the washing assembly of the next washing and settling unit; and in the last washing and settling unit, the solid outlet of the settling component is communicated with the material inlet of one filtering unit. According to the invention, the operation intensity is reduced, the labor cost is saved, the washing efficiency is high, the water consumption for washing is low, the yield is high, and effective recovery of valuable metals is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of battery recycling, and in particular to a washing and separation device and process for recycling leached residue from waste batteries, which can improve the recovery rate of valuable metals, reduce use costs, and simplify operation procedures. Background Art

[0002] In the power battery recycling process, the wet leaching process of black powder involves how to simply and conveniently achieve the washing and recovery of valuable metals entrained in the leaching residue, while further improving the recovery rate of valuable metals.

[0003] In the production process, the filter cake produced by the filter press has a porous structure, so there will always be a part of the mother liquor retained in it. The content of this mother liquor in the filter cake is usually called the moisture content of the filter cake. The lowest is more than 10% and the highest can reach 30-40%. In order to reduce the content of mother liquor in the filter cake, although many improvements have been made to the filter press equipment itself, due to various reasons, the mother liquor content in the filter cake is still not low, which affects the recovery rate of valuable metals.

[0004] For these reasons, the industry generally uses multiple slag washing methods to recover valuable filtrate from the filter cake, reducing the amount of valuable metals in the filter cake's moisture content, thereby effectively improving the recovery rate of valuable metals. Slag washing is a crucial component of the solid-liquid separation process. Each time, the filter cake is re-slurried with fresh washing liquid and re-filtered. This process is repeated multiple times. For waste battery leaching residue containing negative electrode graphite, washing often requires more than 80% of the total separation process due to the strong adsorption capacity of graphite itself. Otherwise, it is difficult to guarantee the recovery of valuable metals. Therefore, existing methods inevitably suffer from high costs, low efficiency, and complex operations. Summary of the Invention

[0005] The present invention provides a short-process method for washing waste battery leaching residue containing negative electrode graphite, which can effectively shorten the process and reduce costs, and is used to solve the technical problems mentioned in the background technology.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is: A countercurrent washing and separation device for recycling leached residue from waste batteries comprises n sequentially connected washing and sedimentation units, wherein the washing and sedimentation units comprise a washing assembly and a sedimentation assembly, the washing assembly being provided with a washing liquid inlet, a material inlet and a material outlet, and the sedimentation assembly being provided with a material inlet, a clear liquid outlet and a solid outlet; in the same washing and sedimentation unit, the material outlet of the washing assembly is connected to the material inlet of the sedimentation assembly; the solid outlet of the sedimentation assembly of the preceding washing and sedimentation unit is connected to the material inlet of the washing assembly of the succeeding washing and sedimentation unit; and in the last washing and sedimentation unit, the solid outlet of the sedimentation assembly is connected to the material inlet of a filtration unit.

[0007] The present invention realizes the step-by-step utilization of washing liquid through the washing design of multiple washing and sedimentation units. The number of washing and sedimentation units can be adjusted according to actual needs, and has good flexibility and scalability. Compared with the traditional multiple slag washing method, the washing device of the present invention integrates multiple slag washing processes into a systematic washing system, which can effectively reduce the amount of washing liquid, significantly increase the content of valuable metals recovered in the washing process, reduce the difficulty of operation, simplify the operation process, and improve production efficiency.

[0008] As a further preferred embodiment of the above technical solution, the clear liquid outlet of the sedimentation component of the subsequent washing and sedimentation unit is connected to the washing liquid inlet of the washing component of the previous washing and sedimentation unit. This design allows the clear liquid of the subsequent washing and sedimentation unit to return to the previous stage as washing liquid, making full use of the concentration gradient of the washing liquid and improving the washing efficiency. The lithium ion concentration at the clear liquid outlet of the sedimentation component of the subsequent washing and sedimentation unit is lower than the lithium ion concentration at the solid outlet of the sedimentation component of the previous washing and sedimentation unit. By mixing the two together and stirring them, a new lithium ion balance is achieved, thereby achieving the purpose of reducing the lithium ion content in the leaching residue; simplifying the leaching residue washing process and reducing the amount of washing water used, and through the ion concentration balance of the valuable metals of the washing component, the content of valuable metal ions in the leaching residue is reduced, thereby improving the recovery rate of valuable metals in the solution.

[0009] As a further preferred embodiment of the above technical solution, the liquid outlet of the filtration unit is connected to the washing liquid inlet of the washing assembly of the (n-1)th washing and settling unit. This design allows the filtrate from the filtration unit to be returned to the washing and settling unit for use as washing liquid, thereby reducing wastewater discharge, achieving resource recycling, and lowering production costs.

[0010] As a further preferred embodiment of the above technical solution, in the washing and settling unit, the washing component is an underflow stirring tank, and the settling component is a vertical settling tank. The vertical settling tank can achieve a solid content of about 60-65% in the sediment and a solid content of 1-2% in the supernatant.

[0011] As a further preferred embodiment of the above technical solution, the number of the washing and sedimentation units is 4.

[0012] Based on the same technical concept, the present invention also provides a countercurrent washing and separation process for recycling leached residue from waste batteries, comprising the following steps: (1) The filter cake produced by the filter press in the wet leaching process of power battery recovery is mixed with the washing liquid to form a slurry; (2) The slurry is sequentially subjected to n-stage washing and sedimentation treatments, wherein the washing and sedimentation treatments include a stirring washing operation and a sedimentation operation, wherein the slurry is mixed with a washing liquid and stirred and washed to form a mixed slurry, followed by sedimentation, and a supernatant and solid residue are obtained by sedimentation. The solid residue obtained from the first-stage washing and sedimentation treatment is used as the slurry raw material for the next-stage washing and sedimentation treatment; (3) The solid product obtained after the slurry is subjected to n-stage washing and sedimentation treatment is filtered, thereby completing the countercurrent washing and separation of the leaching residue recovered from the waste battery.

[0013] As a further preferred embodiment of the above technical solution, in step (2), the supernatant obtained from the latter stage of washing and sedimentation treatment is returned to the former stage of washing and sedimentation treatment for use as washing liquid.

[0014] As a further preferred embodiment of the above technical solution, in step (3), the filtrate obtained from the filtration operation is returned to the n-1th washing and sedimentation treatment for use as a washing liquid.

[0015] As a further preferred embodiment of the above technical solution, in step (2), the number of stages of washing and sedimentation treatment is 4.

[0016] The present invention has the following beneficial effects: 1. Reduced operation intensity: This technology replaces the multiple cycles of leaching residue stirring and washing, filtration pressing, filtration residue stirring and washing, and filtration pressing in the general process, reducing the labor intensity of the traditional process; 2. Save labor costs: The entire process of this technology is automatically controlled, eliminating the labor costs required for slag filtration and slag unloading from the filter plate; 3. High washing efficiency: This technology not only makes the ion concentration in the leaching residue more uniform in the sedimentation tank, but also concentrates the solid materials; 4. Less water consumption for washing: The washing and homogenization time of the leached residue in this technology is long, and the washing effect requirements can be achieved with less water; 5. High yield: The last stage of washing in the process is pure water. Through countercurrent washing, the homogenization effect is good, the leaching residue is washed cleanly, and the effective recovery of valuable metals is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a schematic structural diagram of the washing and separation device for recovering leached residue from waste batteries in Example 1.

[0018] Legend: 1. First underflow agitator tank; 2. Delivery pump; 3. First vertical sedimentation tank; 4. Second underflow agitator tank; 5. Second vertical sedimentation tank; 6. Third underflow agitator tank; 7. Third vertical sedimentation tank; 8. Fourth underflow agitator tank; 9. Fourth vertical sedimentation tank. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below with reference to the embodiments thereof, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0020] Example 1: The washing and separation device for recycling leached residue from waste batteries in this embodiment includes four washing and settling units connected in sequence. The washing and settling units include washing components (a first underflow stirring tank 1, a second underflow stirring tank 4, a third underflow stirring tank 6 and a fourth underflow stirring tank 6) and settling components (a first vertical settling tank 3, a second vertical settling tank 5, a third vertical settling tank 7 and a fourth vertical settling tank 9) connected in sequence. Each washing component is provided with a washing liquid inlet, a material inlet and a material outlet, and each settling component is provided with a material inlet, a clear liquid outlet and a solid outlet. The same washing and settling unit is connected in sequence. In the unit, the material outlet of the washing component is connected to the material inlet of the sedimentation component through the delivery pump 2; the solid outlet of the sedimentation component of the previous washing and sedimentation unit is connected to the material inlet of the washing component of the next washing and sedimentation unit; the clear liquid outlet of the sedimentation component of the next washing and sedimentation unit is connected to the washing liquid inlet of the washing component of the previous washing and sedimentation unit; in the last washing and sedimentation unit, the solid outlet of the sedimentation component is connected to the material inlet of a filtration unit (filter press) through the delivery pump 2, and the liquid outlet of the filter press is connected to the washing liquid inlet of the underflow stirring tank 3.

[0021] Example 2: The washing and separation process for recycling leached residue from waste batteries in this embodiment is implemented using the washing and separation device for recycling leached residue from waste batteries in Example 1, and includes the following steps: (1) The lithium iron phosphate power battery black powder leaching slurry was filtered through a filter press to obtain a leaching residue. The lithium content of the leaching residue was 0.16%, the pH was 1.6, and the lithium concentration in the solution brought out by the leaching residue was 20 g / L; (2) The leached residue is fed into the first underflow stirring tank 1, mixed with the supernatant from the second vertical sedimentation tank 5 (clean water is used for the first use) and stirred for washing, with a residue-liquid ratio of 1:2, to obtain a mixed slurry 1; the mixed slurry 1 is fed into the first vertical sedimentation tank 1 through a delivery pump 2 for solid-liquid sedimentation separation, and the supernatant is output as a slurry raw material for black powder leaching slurry. The water-containing solid matter 1 in the first vertical sedimentation tank 1 is fed into the second underflow stirring tank 4. The lithium content of the water-containing solid matter 1 is 0.08%, and the pH is 4.1; (3) The solid matter in the second underflow agitation tank 4 is mixed with the supernatant from the third vertical sedimentation tank 7 and stirred and washed to obtain a mixed slurry 2; the mixed slurry 2 is sent to the second vertical sedimentation tank 5 through the delivery pump 2 for solid-liquid sedimentation separation, the supernatant is sent to the first underflow agitation tank 1 for slurry adjustment, and the water-containing solid matter 2 in the second vertical sedimentation tank 5 is sent to the third underflow agitation tank 6. The lithium content of the water-containing solid matter 2 is 0.07% and the pH is 5.1; (4) The solid matter in the third underflow agitator tank 6 is mixed with the supernatant from the fourth vertical sedimentation tank 9 and stirred and washed to obtain a mixed slurry 3; the mixed slurry 3 is sent to the third vertical sedimentation tank 7 through the delivery pump 2 for solid-liquid sedimentation separation, and the supernatant is sent to the second underflow agitator tank 4 for slurry adjustment. The water-containing solid matter 3 in the third vertical sedimentation tank 7 is sent to the fourth underflow agitator tank 8. The lithium content of the water-containing solid matter 3 is 0.06% and the pH is 6.1; (5) The solid matter in the fourth underflow agitator tank 8 is mixed with pure water and stirred and washed to obtain a mixed slurry 4; the mixed slurry 4 is sent to the fourth vertical sedimentation tank 9 through the delivery pump 2 for solid-liquid sedimentation separation, and the supernatant is sent to the third underflow agitator tank 6 for slurry adjustment. The water-containing solid matter 4 in the fourth vertical sedimentation tank 9 (the lithium content of the water-containing solid matter 4 is 0.06% and the pH is 6.8) is sent to the filter press for filtration, and the filter residue is sent to the storage yard for storage, and the filtrate is returned to the third underflow agitator tank 6.

[0022] After normal production, the final stage of countercurrent washing produces pure water. The first-stage wash water from the countercurrent washing and settling assembly contains the highest concentration of valuable metals and is returned for use in the next leaching process. The lithium content in the first underflow agitation tank 1 is 11.89 g / L, the second underflow agitation tank 4 is 6.76 g / L, the third underflow agitation tank 6 is 3.21 g / L, and the fourth underflow agitation tank 8 is 0.24 g / L. The countercurrent washing and separation process enriches lithium in the wash water and reduces water consumption, ultimately reducing energy consumption and achieving a slag near-neutral state.

[0023] The above are only preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and modifications obtained without departing from the technical concept of the present invention should also be considered as the scope of protection of the present invention.

[0024] Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A washing and separation device for recycling leached residue from waste batteries, characterized in that: The invention comprises n washing and sedimentation units connected in sequence, wherein the washing and sedimentation units include a washing component and a sedimentation component, the washing component is provided with a washing liquid inlet, a material inlet and a material outlet, and the sedimentation component is provided with a material inlet, a clear liquid outlet and a solid outlet; in the same washing and sedimentation unit, the material outlet of the washing component is connected to the material inlet of the sedimentation component; the solid outlet of the sedimentation component of the previous washing and sedimentation unit is connected to the material inlet of the washing component of the next washing and sedimentation unit; in the last washing and sedimentation unit, the solid outlet of the sedimentation component is connected to the material inlet of a filtration unit.

2. The washing and separation device for recycling leached residue from waste batteries according to claim 1, characterized in that: The clear liquid outlet of the sedimentation component of the subsequent washing and sedimentation unit is communicated with the washing liquid inlet of the washing component of the previous washing and sedimentation unit.

3. The washing and separation device for recycling leached residue from waste batteries according to claim 1, characterized in that: The liquid outlet of the filtering unit is communicated with the washing liquid inlet of the washing assembly of the (n-1)th washing and settling unit.

4. The washing and separation device for recycling leached residue from waste batteries according to any one of claims 1 to 3, characterized in that: In the washing and settling unit, the washing component is an underflow stirring tank, and the settling component is a vertical settling tank.

5. The countercurrent washing and separation device for recycling leached residue from waste batteries according to any one of claims 1 to 3, characterized in that: The number of the washing and settling units is 4.

6. A washing and separation process for recycling leached residue from waste batteries, characterized in that: The following steps are involved: (1) The filter cake produced by the filter press in the wet leaching process of power battery recovery is mixed with the washing liquid to form a slurry; (2) The slurry is sequentially subjected to n-stage washing and sedimentation treatments, wherein the washing and sedimentation treatments include a stirring washing operation and a sedimentation operation, wherein the slurry is mixed with a washing liquid and stirred and washed to form a mixed slurry, followed by sedimentation, and a supernatant and solid residue are obtained by sedimentation. The solid residue obtained from the first-stage washing and sedimentation treatment is used as the slurry raw material for the next-stage washing and sedimentation treatment; (3) The solid product obtained after the slurry is subjected to n-stage washing and sedimentation treatment is filtered, thereby completing the countercurrent washing and separation of the leaching residue recovered from the waste battery.

7. The washing and separation process for recycling leached residue from waste batteries according to claim 6, characterized in that: In step (2), the supernatant obtained from the subsequent washing and sedimentation treatment is returned to the previous washing and sedimentation treatment for use as washing liquid.

8. The washing and separation process for recycling leached residue from waste batteries according to claim 6, characterized in that: In step (3), the filtrate obtained from the filtration operation is returned to the n-1th washing and sedimentation treatment to be used as a washing liquid.

9. The washing and separation process for recycling leached residue from waste batteries according to any one of claims 6 to 8, characterized in that: In step (2), the number of stages of washing and sedimentation treatment is 4.

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