WO2025054876A1 - Lithium battery positive electrode processing wastewater recovery and treatment apparatus and method - Google Patents

Abstract

The present application relates to the technical field of lithium battery positive electrode processing wastewater recovery and treatment. Disclosed are a lithium battery positive electrode processing wastewater recovery and treatment apparatus and method. The apparatus comprises: a collection unit, comprising a first storage tank and a second storage tank, the first storage tank being configured to store phosphorus-containing wastewater, and the second storage tank being configured to store lithium-containing wastewater; a reaction unit, comprising a pool body and a press filtration module, wherein the pool body comprises a reaction chamber and a precipitation chamber communicated with each other, a stirring module is mounted in the reaction chamber, a horizontally arranged filling material layer and a vertically arranged partition plate are mounted in the precipitation chamber, a side of the filling material layer is connected to the partition plate, the partition plate and the filling material layer divide the precipitation chamber into an upper region and a lower region, the press filtration module comprises a diaphragm pump and a filter press, and the lower region is communicated with the filter press by means of the diaphragm pump; and a test unit, comprising a pH meter, a flow meter, and a turbidity meter. According to the recovery and treatment apparatus and method of the present application, wastewater residues can be fully utilized and the costs of wastewater recovery are reduced.

Description

A recycling and treatment device and method for lithium battery positive electrode processing wastewater Technical Field

The present application relates to the technical field of lithium battery positive electrode processing wastewater recovery, and in particular to a lithium battery positive electrode processing wastewater recovery and treatment device and method.

Background Art

On the one hand, iron phosphate needs to be prepared during the processing of lithium battery positive electrodes. Iron phosphate is usually synthesized by liquid phase reaction of ferrous sulfate, hydrogen peroxide and phosphoric acid under certain conditions. During the reaction, wastewater with high phosphorus content will be produced, which needs to be treated in a sewage treatment plant before being discharged. On the other hand, lithium washing wastewater is produced during the processing of lithium battery positive electrodes. The wastewater needs to be adjusted by pH value and then treated by MVR evaporator to recover lithium resources. Therefore, in the current treatment method of lithium battery positive electrode processing wastewater, phosphorus-containing wastewater is not effectively utilized, resulting in high recycling costs.

Summary of the invention

The purpose of this application is to provide a device and method for recycling and treating wastewater from lithium battery positive electrode processing, so as to make more effective use of residual substances in the wastewater and reduce the cost of wastewater recycling.

In order to achieve the above-mentioned purpose, on the one hand, the present application provides a recycling and treatment device for lithium battery positive electrode processing wastewater, comprising:

A collecting unit, comprising a first storage tank and a second storage tank, wherein the first storage tank is used to store phosphorus-containing wastewater, and the second storage tank is used to store lithium-containing wastewater;

The reaction unit comprises a tank body and a filter press module; the tank body comprises a connected reaction chamber and a sedimentation chamber, the reaction chamber is provided with a stirring module, the sedimentation chamber is provided with a horizontally arranged packing layer and a vertically arranged partition, one side of the packing layer is connected to the partition, the partition and the packing layer separate the sedimentation chamber into an upper area and a lower area, when wastewater is input into the sedimentation chamber, the wastewater passes through the packing layer from the lower area, enters the upper area and is discharged; the filter press module comprises a diaphragm pump and a filter press, The lower area is connected to the filter press through the diaphragm pump; the reaction unit is provided with two groups, which are respectively recorded as the first reaction unit and the second reaction unit, the reaction chamber of the first reaction unit is respectively connected to the first storage tank and the second storage tank, and the precipitation chamber of the first reaction unit is connected to the reaction chamber of the second reaction unit;

The detection unit comprises a pH meter, a flow meter and a turbidity meter. The pH meter is installed in the reaction chamber. Two flow meters are provided and are installed at the outlet of the first storage tank and the outlet of the second storage tank respectively. The turbidity meter is installed in the precipitation chamber.

In some embodiments, the collection unit further includes a first centrifugal pump and a second centrifugal pump, the first storage tank is connected to the reaction chamber through the first centrifugal pump, and the second storage tank is connected to the reaction chamber through the second centrifugal pump.

In some embodiments, the cell body further includes a first end cap and a second end cap, wherein the first end cap is sealed on the reaction chamber, and the second end cap is sealed on the precipitation chamber.

In some embodiments, the stirring module includes a motor, a helical gear reducer and a stirring paddle connected in sequence, the helical gear reducer is installed on the upper part of the first end cover, and the stirring paddle is arranged at the lower part of the first end cover.

In some embodiments, a baffle is installed on the inner wall of the reaction chamber, and the baffle is arranged around the outer circumference of the stirring paddle.

In some embodiments, the pool body further includes a sludge scraper and suction machine, and the sludge scraper and suction machine is disposed on the second end cover.

In some embodiments, the packing layer is a honeycomb oblique tube packing layer.

In some embodiments, the tank body further includes a drainage chamber, which is communicated with the upper area of the sedimentation chamber, and the detection unit further includes a liquid level gauge, which is disposed in the drainage chamber.

On the other hand, the present application provides a method for recycling and treating lithium battery positive electrode processing wastewater, comprising:

collecting phosphorus-containing wastewater through a first storage tank and collecting lithium-containing wastewater through a second storage tank;

The first storage tank and the second storage tank are opened to transport the phosphorus-containing wastewater and the lithium-containing wastewater into the reaction chamber of the first reaction unit, and the stirring module is started to obtain mixed wastewater. The pH value of the mixed wastewater is adjusted. After reaching 8-10, it flows into the sedimentation chamber of the first reaction unit, is filtered through the packing layer in the sedimentation chamber, and is precipitated in the lower area of the sedimentation chamber to form magnesium phosphate, and forms filtered wastewater in the upper area of the sedimentation chamber;

The upper area of the sedimentation chamber of the first reaction unit is opened to transport the filtered wastewater into the reaction chamber of the second reaction unit, and the stirring module is started to adjust the pH value of the filtered wastewater to 11-13, and then the filtered wastewater flows into the sedimentation chamber of the second reaction unit, and is filtered through the packing layer in the sedimentation chamber to precipitate in the lower area of the sedimentation chamber to form lithium phosphate, and is discharged in the upper area of the sedimentation chamber as clean water;

The diaphragm pumps of the first reaction unit and the second reaction unit are started to transport the magnesium phosphate and the lithium phosphate to the filter press respectively, and the magnesium phosphate filter cake and the lithium phosphate filter cake are obtained by pressing.

In some embodiments, the pH value of the mixed wastewater and the filtered wastewater is adjusted by injecting liquid alkali.

The present application provides a lithium battery positive electrode processing wastewater recovery and treatment device, which has the following beneficial effects compared with the prior art:

The first storage tank is used to store phosphorus-containing wastewater, and the second storage tank is used to store lithium-containing wastewater. Both wastewaters are generated during the processing of lithium battery positive electrodes. The reaction unit includes a cell body and a filter press module. The two wastewaters are mixed in the cell body to react and form precipitates, which are then squeezed through the filter press module to obtain magnesium phosphate filter cakes and lithium phosphate filter cakes, so that the materials in the wastewater can be effectively recovered, the residual substances in the wastewater can be more fully utilized, and the cost of wastewater recovery can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of a device for recycling and treating lithium battery positive electrode processing wastewater provided in an embodiment of the present application.

2 is a schematic diagram of the enlarged structure of the cell body of the first reaction unit of the lithium battery positive electrode processing wastewater recovery and treatment device provided in an embodiment of the present application.

3 is an enlarged structural schematic diagram of the filter press module of the lithium battery positive electrode processing wastewater recovery and treatment device provided in an embodiment of the present application.

4 is a schematic diagram of the enlarged structure of the stirring module of the lithium battery positive electrode processing wastewater recovery and treatment device provided in an embodiment of the present application.

FIG. 5 shows the molar concentrations of lithium ions, magnesium ions and phosphate ions in the solution at different pH values.

In the figure: 100, recycling and processing device; 1, collecting unit; 11, first storage tank; 12, second storage tank; 2, reaction unit; 21, tank body; 210, drainage chamber; 211, reaction chamber; 212, sedimentation chamber; 212a, upper area; 212b, lower area; 213, stirring module; 2131, motor; 2132, helical gear reducer; 2133, stirring paddle; 214, packing layer; 215, partition; 216, first end cover; 217, second end cover; 218, baffle; 219, hanging suction machine; 23, filter press module; 231, diaphragm pump; 232, filter press; 3, detection unit; 31, pH meter; 32, flow meter; 33, turbidity meter; 34, liquid level meter.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

It should be understood that, in the description of the present application, the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, that is, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, unless otherwise specified, "multiple" means two or more.

As shown in Figures 1-4, a lithium battery positive electrode processing wastewater recovery and treatment device 100 provided in an embodiment of the present application includes: a collection unit 1, including a first storage tank 11 and a second storage tank 12, the first storage tank 11 is used to store phosphorus-containing wastewater, and the second storage tank 12 is used to store lithium-containing wastewater; a reaction unit 2, which includes a cell body 21 and a filter press module 23; the cell body 21 includes a reaction chamber 211 and a sedimentation chamber 212 connected to each other, the reaction chamber 211 is equipped with a stirring module 213, and the sedimentation chamber 212 is equipped with a stirring module 213. A horizontally arranged packing layer 214 and a vertically arranged partition 215 are installed inside, one side of the packing layer 214 is connected to the partition 215, and the partition 215 and the packing layer 214 separate the sedimentation chamber 212 into an upper area 212a and a lower area 212b. When wastewater is input into the sedimentation chamber 212, the wastewater passes through the packing layer 214 from the lower area 212a, enters the upper area 212b and is discharged; the filter press module 23 includes a diaphragm pump 231 and a filter press 232, and the lower area 212b is connected to the filter press 232 through the diaphragm pump 231; the reaction unit 2 is provided with two groups, which are respectively recorded as the first reaction unit and the second reaction unit, and the reaction chamber 211 of the first reaction unit is respectively connected to the first storage tank 11 and the second storage tank 12, and the sedimentation chamber 212 of the first reaction unit is connected to the reaction chamber 211 of the second reaction unit;

The detection unit 3 includes a pH meter 31, a flow meter 32 and a turbidity meter 33. The pH meter 31 is installed in the reaction chamber 211. Two flow meters 32 are provided and are installed at the outlet of the first storage tank 11 and the outlet of the second storage tank 11 respectively. The turbidity meter 33 is installed in the sedimentation chamber.

Based on the above-mentioned configuration, the first storage tank 11 is used to store phosphorus-containing wastewater, and the second storage tank 12 is used to store lithium-containing wastewater. Both wastewaters are wastewater generated during the processing of lithium battery positive electrodes; the reaction unit 2 includes a cell body 21 and a filter press module 23. The two wastewaters are mixed in the cell body 21 for reaction, and the filter press module 23 is used to press to obtain magnesium phosphate filter cake and lithium phosphate filter cake, so that the materials in the wastewater can be effectively recovered, the residual substances in the wastewater can be more fully utilized, and the cost of wastewater recovery can be reduced.

In one embodiment, the collection unit 1 further includes a first centrifugal pump and a second centrifugal pump, the first storage tank 11 is connected to the reaction chamber 211 through the first centrifugal pump, and the second storage tank 12 is connected to the reaction chamber 211 through the second centrifugal pump. The first centrifugal pump and the second centrifugal pump can stably transport the wastewater in the first storage tank 11 and the second storage tank 12 to the reaction chamber 211 of the first reaction unit.

As shown in Fig. 2, the cell body 21 further includes a first end cap 216 and a second end cap 217. The first end cap 216 is sealed on the reaction chamber 211, and the second end cap 217 is sealed on the sedimentation chamber 212. The first end cap 216 and the second end cap 217 are provided so that the wastewater in the reaction chamber 211 and the sedimentation chamber 212 will not leak out during the reaction process.

Specifically, as shown in FIG. 4 , the stirring module 213 includes a motor 2131, The helical gear reducer 2132 and the stirring paddle 2133, the helical gear reducer 2132 is installed on the upper part of the first end cover 216, and the stirring paddle 2133 is arranged on the lower part of the first end cover 216, so that the installation structure of the stirring module 213 is stable; when working, the starting motor 2131 is adjusted through the helical gear reducer 2132, and the available output torque is increased without increasing the power consumption of the motor 2131, so that the stirring paddle 2133 can stir and mix the wastewater in the reaction chamber 211.

Optionally, a baffle 218 is installed on the inner wall of the reaction chamber 211, and the baffle 218 is arranged around the outer periphery of the stirring paddle 2133. The baffle 218 has an anti-swirl effect, so that the wastewater is mixed more evenly.

In one embodiment, the tank body 21 further includes a sludge scraper 219, which is disposed on the second end cover 217. The sludge scraper 219 is used to maintain and clean the tank body 21 when the tank body 21 is not in use.

Specifically, the packing layer 214 is a honeycomb inclined tube packing layer. When the wastewater passes through the honeycomb inclined tube packing layer, a swirling flow is formed, so that a large contact area is generated between the sediment and the liquid, thereby accelerating the sedimentation of the sediment.

In one embodiment, the pool body 21 also includes a drainage chamber 210, which is connected to the upper area 212a of the sedimentation chamber 212, wherein the liquid in the drainage chamber 210 of the first reaction unit flows into the reaction chamber 211 of the second reaction unit, and the detection unit 3 also includes a liquid level gauge 34, which is arranged in the drainage chamber 210, and the liquid level gauge 34 is used to detect the liquid level height of the drainage chamber 210; according to actual needs, the liquid level gauge 34 can also be installed in the first storage tank 11, the second storage tank 12 and the reaction chamber 211 to measure the liquid level height.

Another embodiment of the application provides a method for recycling and treating lithium battery positive electrode processing wastewater, comprising:

The phosphorus-containing wastewater is collected by the first storage tank 11, and the lithium-containing wastewater is collected by the second storage tank 12; it should be noted that the phosphorus-containing wastewater is generated in the process of preparing iron phosphate, which is usually synthesized by liquid phase reaction of ferrous sulfate, hydrogen peroxide and phosphoric acid under certain conditions, and wastewater with high phosphorus content is generated during the reaction. The lithium-containing wastewater is generated in the process of lithium washing, and the wastewater also contains magnesium ions.

Open the first storage tank 11 and the second storage tank 12 to transport the phosphorus-containing wastewater and the lithium-containing wastewater to the In the reaction chamber 211 of a reaction unit, the stirring module 213 is started to obtain mixed wastewater, and the pH value of the mixed wastewater is adjusted to 8-10 and then flows into the sedimentation chamber 212 of the first reaction unit. After being filtered through the packing layer 214 in the sedimentation chamber 212, magnesium phosphate is precipitated in the lower area 212b of the sedimentation chamber 212, and filtered wastewater is formed in the upper area 212a of the sedimentation chamber 212.

The upper area 212a of the sedimentation chamber 212 of the first reaction unit is opened to transport the filtered waste water to the reaction chamber 211 of the second reaction unit, and the stirring module 213 is started to adjust the pH value of the filtered waste water to 11-13 and then flow into the sedimentation chamber 212 of the second reaction unit. After being filtered through the filler layer 214 in the sedimentation chamber 212, the waste water is precipitated in the lower area 212b of the sedimentation chamber 212 to form lithium phosphate, and clean water is formed in the upper area 212a of the sedimentation chamber 212 for discharge. After the clean water is discharged into the drainage chamber 210, the pH value of the clean water is adjusted to 6-9 (optionally 7) by injecting acidic substances before being discharged.

As shown in FIG5 , by comparing the molar concentrations of lithium ions, magnesium ions and phosphate ions in the solution under different pH values (the lower the molar concentration, the more precipitates in the solution), it can be seen that when magnesium phosphate is precipitated, the pH value can be optionally adjusted to 9; when lithium phosphate is precipitated, the pH value can be optionally adjusted to 12. Through the above steps, magnesium phosphate and lithium phosphate are precipitated in the precipitation chambers 212 of the first reaction unit and the second reaction unit, respectively.

In another embodiment, the diaphragm pumps 231 of the first reaction unit and the second reaction unit are started to transport magnesium phosphate and lithium phosphate to the filter press 232 respectively, and the magnesium phosphate filter cake and the lithium phosphate filter cake are obtained by squeezing. The diaphragm pump 231 is a pneumatic diaphragm pump, and the filter press 232 is a diaphragm filter press; the wastewater generated by the diaphragm filter presses of the first reaction unit and the second reaction unit after the filtration operation is transported to the sedimentation chambers 212 of the first reaction unit and the second reaction unit for reuse.

In another embodiment, the pH value of the mixed wastewater and the filtered wastewater is adjusted by injecting liquid alkali.

The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present application. These improvements and substitutions should also be regarded as the scope of protection of the present application.

Claims (10)

A recycling and treatment device for lithium battery positive electrode processing wastewater, characterized by comprising: A collection unit (1), comprising a first storage tank (11) and a second storage tank (12), wherein the first storage tank (11) is used to store phosphorus-containing wastewater, and the second storage tank (12) is used to store lithium-containing wastewater; A reaction unit (2) comprises a tank body (21) and a filter press module (23); the tank body (21) comprises a reaction chamber (211) and a sedimentation chamber (212) which are connected to each other; a stirring module (213) is installed in the reaction chamber (211); a horizontally arranged packing layer 214 and a vertically arranged partition (215) are installed in the sedimentation chamber (212); one side of the packing layer (214) is connected to the partition (215); the partition (215) and the packing layer (214) separate the sedimentation chamber (212) into an upper area (212a) and a lower area (212b); when wastewater is input into the sedimentation chamber (212), the wastewater flows from the lower area (212a) to the sedimentation chamber (212). The lower region (212b) passes through the packing layer (214), enters the upper region (212a) and is discharged; the filter press module (23) comprises a diaphragm pump (231) and a filter press (232), and the lower region (212b) is connected to the filter press (232) via the diaphragm pump (231); the reaction unit (2) is provided with two groups, which are respectively denoted as a first reaction unit and a second reaction unit, the reaction chamber (211) of the first reaction unit is respectively connected to the first storage tank (11) and the second storage tank (12), and the precipitation chamber (212) of the first reaction unit is connected to the reaction chamber (211) of the second reaction unit; A detection unit (3) comprising a pH meter (31), a flow meter (32) and a turbidity meter (33); the pH meter (31) is installed in the reaction chamber (211); two flow meters (32) are provided and are installed at the outlet of the first storage tank (11) and the outlet of the second storage tank (12) respectively; and the turbidity meter (33) is installed in the sedimentation chamber (212). The device for recycling and treating lithium battery positive electrode processing wastewater according to claim 1 is characterized in that: the collection unit (1) also includes a first centrifugal pump and a second centrifugal pump, the first storage tank (11) is connected to the reaction chamber (211) through the first centrifugal pump, and the second storage tank (12) is connected to the reaction chamber (211) through the second centrifugal pump. The device for recycling and treating lithium battery positive electrode processing wastewater according to claim 1 is characterized in that: the cell body (21) also includes a first end cover (216) and a second end cover (217), the first end cover (216) is sealed on the reaction chamber (211), and the second end cover (217) is sealed on the sedimentation chamber (212). The recycling and treatment device for lithium battery positive electrode processing wastewater according to claim 3 is characterized in that: the stirring module (213) includes a motor (2131), a helical gear reducer (2132) and a stirring paddle (2133) connected in sequence, the helical gear reducer (2132) is installed on the upper part of the first end cover (216), and the stirring paddle (2133) is arranged at the lower part of the first end cover (216). The device for recycling and treating lithium battery positive electrode processing wastewater according to claim 4 is characterized in that a baffle (218) is installed on the inner wall of the reaction chamber (211), and the baffle (218) is arranged around the outer periphery of the stirring paddle (2133). The device for recycling and treating lithium battery positive electrode processing wastewater according to claim 3 is characterized in that: the cell body (21) also includes a sludge scraper (219), and the sludge scraper (219) is arranged on the second end cover (217). The lithium battery positive electrode processing wastewater recovery and treatment device according to claim 1 is characterized in that the packing layer (214) is a honeycomb inclined tube packing layer. The device for recycling and treating lithium battery positive electrode processing wastewater according to claim 1 is characterized in that: the cell body (21) also includes a drainage chamber (210), the drainage chamber (210) is connected to the upper area (212a) of the sedimentation chamber (212), and the detection unit (3) also includes a liquid level meter (34), and the liquid level meter (34) is arranged in the drainage chamber (210). A method for recycling and treating lithium battery positive electrode processing wastewater, characterized by comprising: collecting phosphorus-containing wastewater through a first storage tank (11) and collecting lithium-containing wastewater through a second storage tank (12); The first storage tank (11) and the second storage tank (12) are opened to transport the phosphorus-containing wastewater and the lithium-containing wastewater into the reaction chamber (211) of the first reaction unit, and the stirring module (213) is started to obtain mixed wastewater. The pH value of the mixed wastewater is adjusted to 8 to 10 and then flows into the sedimentation chamber (212) of the first reaction unit, and is filtered through the packing layer (214) in the sedimentation chamber (212). The magnesium phosphate is precipitated in the lower region (212b) of the (212) and filtered wastewater is formed in the upper region (212a) of the precipitation chamber (212); The upper region (212a) of the sedimentation chamber (212) of the first reaction unit is opened to transport the filtered wastewater to the reaction chamber (211) of the second reaction unit, and the stirring module (213) is started to adjust the pH value of the filtered wastewater to 11-13, and then the filtered wastewater flows into the sedimentation chamber (212) of the second reaction unit, and is filtered through the packing layer (214) in the sedimentation chamber (212) and precipitated in the lower region (212b) of the sedimentation chamber (212) to form lithium phosphate, and is discharged as clean water in the upper region (212a) of the sedimentation chamber (212); The diaphragm pumps (231) of the first reaction unit and the second reaction unit are started to transport magnesium phosphate and lithium phosphate to the filter press (232) respectively, and the magnesium phosphate filter cake and the lithium phosphate filter cake are obtained by squeezing. The method for recycling and treating lithium battery positive electrode processing wastewater according to claim 9 is characterized in that the pH value of the mixed wastewater and the filtered wastewater is adjusted by injecting liquid alkali.