Equipment and method for removing heavy metals and fluorine ions in lithium battery wet recovery wastewater treatment

Abstract

The invention relates to the technical field of industrial wastewater, and discloses equipment for removing heavy metals and fluorine ions in lithium battery wet recovery wastewater treatment. And the outer wall of the upper end of the contact precipitation equipment is communicated with a contact precipitation equipment water inlet pipe. The method comprises the following steps: performing primary treatment on heavy metals and fluorine ions in the lithium battery wet recovery wastewater through contact precipitation equipment by utilizing chelation and good flocculation performance of a contact material of a contact material layer, treating medium-concentration heavy metals and fluorine ions to low-concentration heavy metals and fluorine ions, and adsorbing and filtering the wastewater through adsorption and filtration equipment, so as to obtain high-concentration heavy metals and fluorine ions in the lithium battery wet recovery wastewater. A large amount of heavy metal and fluorine ions can be adsorbed like sponge by utilizing special pore channels and an open framework molecular structure in the adsorption filtering material of the adsorption filtering material layer, after secondary advanced treatment, the concentration of the heavy metal and the fluorine ions can reach the national related reclaimed water reuse or discharge standard, and the method has the advantages of high treatment efficiency, low cost and the like. And the operation cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of industrial wastewater, and in particular to a device and method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment. Background Art

[0002] With the popularity of electronic products such as electric vehicles and smart phones, the demand for lithium batteries as their core power source has shown explosive growth. However, it also brings an environmental problem that cannot be ignored: the recycling and disposal of waste lithium batteries.

[0003] A large amount of wastewater is generated during the disassembly, crushing and separation processes of waste lithium batteries during recycling and treatment. The wastewater has complex components and contains a variety of heavy metal ions (such as cobalt, nickel, copper, etc.), organic matter (such as organic solvents, electrolytes, etc.), oils, salts and other pollutants. The presence of these substances makes wastewater treatment more difficult.

[0004] In addition, the recycling of waste power lithium batteries in China still relies on wet refining. During this process, the presence of electrolyte and the limitations of the process flow will inevitably lead to the enrichment of fluoride ions in the process of preparing lithium salt compounds, resulting in excessive fluorine content and environmental pollution problems.

[0005] At present, the traditional coagulation sedimentation method and adsorption method are generally used in China to recover heavy metals and fluoride ions from lithium battery wastewater by wet method. In the traditional coagulation sedimentation method, calcium salt is added to produce insoluble heavy metals and calcium fluoride precipitation to remove heavy metals and fluoride ions, but it cannot achieve deep removal of heavy metals; in the traditional adsorption method, aluminum sulfate is added to remove heavy metals and fluoride ions by adsorption, but this method requires large input, has high removal cost and will cause difficulty in sludge filtration, which is not conducive to production.

[0006] To this end, we proposed a device and method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment to solve the problem. Summary of the invention

[0007] The purpose of the present invention is to provide a device and method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment, which solves the problems in the above-mentioned background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a device for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment, comprising:

[0009] Contact precipitation equipment;

[0010] The outer wall of the upper end of the contact sedimentation device is connected to a water inlet pipe of the contact sedimentation device, and a guide area is provided inside the contact sedimentation device, a support plate is provided in the middle and lower part between the wall plate of the guide area and the tail box wall, a cushion layer is provided on the support plate, the top surface of the cushion layer has a contact material layer, the top of the contact material layer is a clean water area, a recoil air pipe is provided below the support plate, a sludge hopper is provided at the lower part of the contact sedimentation device, a sludge discharge pipe is provided at the bottom of the sludge hopper, a post-sedimentation clean water trough is provided in the contact sedimentation device, a water hole is provided on the common wall of the contact sedimentation device and the post-sedimentation clean water trough, a submersible lifting pump is provided at the bottom of the post-sedimentation clean water trough, and the submersible lifting pump is connected to a lifting pump outlet pipe;

[0011] Adsorption filtration equipment;

[0012] The lower part of the adsorption filter equipment is an adsorption filter box, and the upper part is an adsorption filter water storage tank, and they are separated by a steel partition. The upper part of the adsorption filter box is provided with an adsorption filter box water inlet pipe valve, and the adsorption filter box water inlet pipe valve is connected to the lifting pump outlet pipe. The bottom plate of the adsorption filter box and the bottom of the filter plate and filter head assembly constitute a backwashing water distribution and air distribution space. A supporting layer is provided on the filter head and filter plate assembly. A backwashing drain pipe valve is provided at the end of the adsorption filter box water inlet pipe valve. A connecting pipe valve is provided between the bottom of the water storage tank after adsorption filtration and the backwashing water distribution and air distribution space at the bottom of the adsorption filter box. The backwashing water distribution and air distribution space is provided with a bottom drain pipe valve, and the backwashing water distribution and air distribution space is provided with a backwashing air pipe valve;

[0013] Centrifugal fan;

[0014] The air outlet of the centrifugal fan is connected to the backwash air pipe and the backwash air pipe valve respectively through the air delivery pipe valve.

[0015] Preferably, the contact sedimentation equipment and the adsorption filtration equipment both adopt an integrated casing and are made of corrosion-resistant carbon steel.

[0016] Preferably, the support plate material is made of anti-corrosion steel plate, the support plate has holes, and the hole diameter is 15mm, the hole spacing is 115mm, and the support plate is covered with a nylon mesh with a specification of 36 mesh / inch.

[0017] Preferably, the cushion material is pebbles with a particle size of 1625 mm and a laying thickness of 100 mm.

[0018] Preferably, the contact material layer is a mixture of 24 mm crayfish shells obtained by processing, crushing and screening, non-ionic polyacrylamide and polyferric chloride, and the contact material layer is laid with a thickness of 500 mm.

[0019] Preferably, the filter plates of the filter plate and filter head assembly are spliced ​​steel plates, and the size of a single filter plate is 980×980 (mm). At the same time, the single filter plate has a hole setting, the hole diameter is 25mm, the spacing is 125×125 (mm), and an adjustable ABS long-handled filter head is installed on the hole.

[0020] Preferably, the supporting layer material is quartz sand with a particle size of 24 (mm), the supporting layer thickness is 200mm, an adsorption filter material layer is arranged on the supporting layer, and the adsorption filter material layer is composed of processed crayfish shells, zeolite, rectorite, etc., which are crushed to a particle size of less than 100 mesh, and then a small amount of sodium polyacrylate and a pore-forming agent are added for dry powder mixing, and then 20% of water is added to mix and granulate to form a particle size of 12mm. The thickness of the adsorption filter material layer is 1500mm, and a top drain valve of the adsorption filter material layer is arranged on the top of the adsorption filter material layer, and an adsorption filter tank outlet channel and a post-filtration water pipe are arranged at the designed water level of the adsorption filter tank.

[0021] In addition to the above technical solutions, the present invention also includes:

[0022] A method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment comprises the following steps:

[0023] S1: Lithium battery wet recovery wastewater enters the diversion area through the water inlet pipe of the contact sedimentation equipment, bypasses the diversion plate, and enters the clean water area through the support plate, cushion layer, and contact material layer;

[0024] S2: entering the post-sedimentation clean water tank through a water hole provided on the common wall of the contact sedimentation equipment and the post-sedimentation clean water tank;

[0025] S3: The water enters the adsorption filter box of the adsorption filter equipment through the submersible lifting pump and the lifting pump outlet pipe and the adsorption filter box inlet pipe valve connected thereto arranged at the bottom of the clear water tank after sedimentation;

[0026] S4: Most of the heavy metals and fluoride ions are precipitated and stored in the sludge hopper after mud-water separation due to the chelation effect of the contact material layer on the heavy metal ions and the flocculation effect on the fluoride ions. In addition, a small part is retained in the contact material layer. In order to avoid the accumulation of sludge containing heavy metals and fluoride ions in the contact material layer during operation, resulting in excessive head loss, backwashing is performed regularly using the backwashing air pipe set under the support plate. The backwashing cycle of regular backwashing is 7 days, the backwashing gas intensity is 15L / (S·㎡), the backwashing time is 23min, and the backwashing air source is supplied by the air outlet of the centrifugal fan through the air delivery pipe valve and the backwashing air pipe connected thereto. The sludge in the sludge hopper is discharged from the sludge discharge pipe and recycled and resourced by qualified units. The contact sedimentation time of the contact sedimentation equipment is 20-30min;

[0027] S5: After primary treatment in the contact material layer of the contact precipitation equipment, the heavy metals and fluoride ions in the lithium battery wet recovery wastewater can be reduced from medium concentration to low concentration.

[0028] In addition to the above technical solutions, the present invention also includes:

[0029] A1: After the heavy metals and fluoride ions in the lithium battery wet recovery wastewater are removed in the first stage by the contact precipitation equipment, they enter the adsorption filtration equipment for secondary deep removal through the submersible lifting pump, the lifting pump outlet pipe and the adsorption filtration box inlet pipe connected to the bottom of the clear water tank after precipitation.

[0030] A2: During the adsorption filtration treatment, the treated water enters the backwash water and air distribution space through the adsorption filter box water inlet valve, adsorption filter filter material layer, support layer, filter plate and filter head assembly. The adsorption filtration water flows upward through the connecting pipe valve into the adsorption filtration post-water storage tank, and finally flows out from the adsorption filtration post-water storage tank outlet channel and the post-filtration water pipe connected thereto for recycling or discharge in compliance with the standards.

[0031] A3: When the treated water passes through the adsorption filter layer, due to the special pores and open framework molecular structure inside the filter material, it can absorb a large amount of heavy metals and fluoride ions like a sponge and remove them. When the adsorption filter head through the adsorption filter layer reaches the set value, backwashing is performed. When backwashing, first close the adsorption filter box water inlet valve and the connecting pipe valve, open the bottom drain pipe valve for 3 minutes, drain part of the water from the backwashing water and air distribution space, and lower the water level to 200mm on the surface of the adsorption filter layer. Open the top drain valve of the adsorption filter layer to drain the water above the top drain valve of the adsorption filter layer. Then open the backwash air pipe valve to backwash the adsorption filter layer for 8 minutes, and then open the connecting pipe valve and the backwash drain pipe valve for 4 minutes, so that the water in the water tank after adsorption filtration passes from bottom to top through the backwashing water and air distribution space, the filter plate and filter head assembly, and the supporting layer to backwash the adsorption filter layer.

[0032] A4: Finally, close the backwash drain valve, open the adsorption filter box water inlet valve and restart the adsorption filtration. The backwash cycle is 48 hours. The adsorption filtration rate of the adsorption filtration equipment is 2 m / h, the air flushing intensity is 1216 L / (S·㎡), and the water flushing intensity is 34 L / (S·㎡). The air source for air and water flushing is supplied from the air outlet of the centrifugal fan (3) through the backwash air pipe valve.

[0033] A5: After secondary treatment through the adsorption filtration filter layer of the adsorption filtration equipment, the heavy metals and fluoride ions in the lithium battery wet recovery wastewater can be reduced from low concentrations to the national standards for reclaimed water reuse or discharge.

[0034] The present invention provides a device and method for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater. The device and method for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater have the following beneficial effects:

[0035] The present invention uses contact precipitation equipment and utilizes the chelating effect and good flocculation performance of the contact material layer to perform primary treatment on heavy metals and fluoride ions in lithium battery wet recovery wastewater, treats medium-concentration heavy metals and fluoride ions to low concentrations, and then passes through adsorption filtration equipment, utilizes the special pores and open framework molecular structure inside the adsorption filtration filter material layer to enable it to adsorb a large amount of heavy metals and fluoride ions like a sponge. After secondary deep treatment, the concentration of heavy metals and fluoride ions can meet the relevant national standards for reclaimed water reuse or discharge, and has the characteristics of high treatment efficiency and low operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a structural flow diagram of a device and method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment.

[0037] In the figure:

[0038] 1-contact sedimentation equipment, 1-1-contact sedimentation equipment water inlet pipe, 1-2-diversion area, 1-3-support plate, 1-4-cushion, 1-5-contact material layer, 1-6-clean water area, 1-7-water hole, 1-8-recoil air pipe, 1-9-sludge hopper, 1-10-sludge discharge pipe, 1-11-clean water tank after sedimentation, 1-12-submersible lifting pump, 1-13-lifting pump outlet pipe;

[0039] 2-adsorption filtration equipment, 2-1-adsorption filter box, 2-2-water storage tank after adsorption filtration, 2-3-water inlet pipe valve of adsorption filter box, 2-4-air room for backwashing water distribution and air distribution, 2-5-filter plate and filter head assembly, 2-6-supporting layer, 2-61-adsorption filtration filter material layer, 2-7-backwashing drainage pipe valve, 2-8-connecting pipe valve, 2-9-bottom drainage pipe valve, 2-10-backwashing air pipe valve, 2-11-top drainage valve of adsorption filtration filter material layer, 2-12-water outlet channel of water storage tank after adsorption filtration, 2-13-water pipe after filtration;

[0040] Centrifugal fan, 3-1-air inlet and air inlet pipe, 3-2-air outlet, 3-3-air delivery pipe valve. DETAILED DESCRIPTION

[0041] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0042] Example 1: A preferred embodiment of the device and method for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater provided by the present invention is as follows: Figure 1 Shown: A device for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment, comprising:

[0043] The contact sedimentation equipment 1 adopts an integrated box body and is made of anti-corrosion carbon steel;

[0044] The outer wall at the upper end of the contact sedimentation device 1 is connected to a contact sedimentation device water inlet pipe 1-1, and a guide area 1-2 is arranged inside the contact sedimentation device 1. A support plate 1-3 is arranged in the middle and lower part between the wall plate of the guide area 1-2 and the tail box wall. The support plate 1-3 is made of steel plate for corrosion resistance. The support plate 1-3 has a hole setting, and the hole diameter of the hole is 15mm, and the hole spacing is 115mm. The support plate 1-3 is covered with a nylon mesh with a specification of 36 meshes / inch. A cushion layer 1-4 is arranged on the support plate 1-3. The cushion layer 1-4 is made of pebbles with a particle size of 16-25mm and a laying thickness of 1 00mm, the top surface of the cushion layer 1-4 is provided with a contact material layer 1-5, the material of the contact material layer 1-5 is a mixed material of 2-4mm crayfish shells obtained by processing, crushing and screening, non-ionic polyacrylamide and polyferric chloride, and the laying thickness of the contact material layer 1-5 is 500mm. Its specific preparation is that the crayfish shells are pre-treated and then pickled, washed, boiled in alkali, decolorized, reduced, washed and dried, and then crushed and screened to a particle size of 2-4min and fully mixed with powdered non-ionic polyacrylamide NPAM and granular polyferric chloride PFS to obtain the contact material layer 1-5 contact material. The mass percentage ratio of the contact material in the contact material layer 1-5 is: 90% of the crayfish shell processed to 2-4mm, 1% of the non-ionic polyacrylamide NPAM, and 9% of the polyferric chloride PFS. The upper part of the contact material layer 1-5 is the clean water area 1-6, and a recoil air pipe 1-8 is arranged below the support plate 1-3. A sludge hopper 1-9 is arranged at the lower part of the contact sedimentation equipment 1, and a sludge discharge pipe 1-10 is arranged at the bottom of the sludge hopper 1-9. A post-sedimentation clean water tank 1-11 is arranged in the contact sedimentation equipment 1. A water hole 1-7 is arranged on the common wall of the contact sedimentation equipment 1 and the post-sedimentation clean water tank 1-11. A submersible lifting pump 1-12 is arranged at the bottom of the post-sedimentation clean water tank 1-11, and a lifting pump outlet pipe 1-13 is arranged in communication with the submersible lifting pump 1-12.

[0045] A method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment comprises the following steps:

[0046] S1: Lithium battery wet recovery wastewater enters the diversion area 1-2 through the contact sedimentation equipment water inlet pipe 1-1, bypasses the guide plate, and enters the clean water area 1-6 through the support plate 1-3, the cushion layer 1-4, and the contact material layer 1-5;

[0047] S2: The water enters the post-sedimentation clean water tank 1-11 through the water hole 1-7 provided on the common wall of the contact sedimentation device 1 and the post-sedimentation clean water tank 1-11;

[0048] S3: The water enters the adsorption filter box 2-1 of the adsorption filter device 2 through the submersible lifting pump 1-12 and the lifting pump outlet pipe 1-13 arranged at the bottom of the clear water tank 1-11 after sedimentation and the adsorption filter box inlet pipe valve 2-3 connected thereto;

[0049] S4: Most of the heavy metals and fluoride ions are precipitated and stored in the sludge hopper 1-9 after mud-water separation due to the chelation effect of the contact material of the contact material layer 1-5 on the heavy metal ions and the flocculation effect on the fluoride ions. In addition, a small part is retained in the contact material layer 1-5. In order to avoid the accumulation of sludge containing heavy metals and fluoride ions in the contact material layer 1-5 during operation, resulting in excessive head loss, the backwashing is performed regularly using the backwashing air pipe 1-8 arranged under the support plate 1-3. The backwashing cycle of the regular backwashing is 7 days, the backwashing gas intensity is 15L / S·㎡, and the backwashing time is 2-3min. The backwashing air source is supplied by the air outlet 3-2 of the centrifugal fan 3 through the air delivery pipe valve 3-3 and the backwashing air pipe 1-8 connected thereto. The sludge in the sludge hopper 1-9 is discharged from the sludge discharge pipe 1-10 and is recycled and recycled by a qualified unit. The contact sedimentation time of the contact sedimentation equipment 1 is 20-30min.

[0050] S5: After primary treatment by the contact material layers 1-5 of the contact precipitation device 1, the heavy metals and fluoride ions in the lithium battery wet recovery wastewater can be reduced from medium concentration to low concentration.

[0051] Example 2: Based on the above embodiment, adsorption filtration device 2;

[0052] The lower part of the adsorption filter device 2 is an adsorption filter box 2-1, and the upper part is an adsorption filter water storage tank 2-2, which are separated by a steel partition. The upper part of the adsorption filter box 2-1 is provided with an adsorption filter box water inlet pipe valve 2-3, and the adsorption filter box water inlet pipe valve 2-3 is connected to the lifting pump outlet pipe 1-3. The bottom plate of the adsorption filter box 2-1 and the bottom of the filter plate filter head assembly 2-5 constitute a backwashing water distribution and air distribution space 2-4. The filter plate of the filter plate filter head assembly 2-5 is a steel plate splicing, and the single filter The plate size is 980×980mm. A single filter plate is provided with a hole setting. The hole diameter is 25mm and the spacing is 125×125mm. An adjustable ABS long-handled filter head is installed on the hole. A supporting layer 2-6 is arranged on the filter head and filter plate assembly 2-5. The supporting layer 2-6 is made of quartz sand with a particle size of 2-4mm. The thickness of the supporting layer 2-6 is 200mm. An adsorption filter material layer 2-61 is arranged on the supporting layer 2-6. The adsorption filter material layer 2-61 adsorption filter The material is the processed crayfish shell, zeolite, rectorite, etc., which are crushed to a particle size of less than 100 mesh, and then a small amount of sodium polyacrylate and pore-forming agent are added to mix the dry powder, and then 20% of water is added to mix and granulate to form a particle size of 1-2mm. The thickness of the adsorption and filtration filter material layer 2-61 is 1500mm. The top of the adsorption and filtration filter material layer 2-61 is provided with an adsorption and filtration filter material layer top drainage valve 2-11, and the adsorption and filtration water storage tank 2-2 is provided at the design water level of the adsorption and filtration water storage tank The outlet channel 2-12 and the filtered water pipe 2-13 are specifically prepared by pre-treating the crayfish shells, acid soaking, water washing, alkali boiling, decolorization, water washing, drying, and then crushing to a particle size of less than 100 mesh; respectively crushing zeolite and rectorite to a particle size of less than 100 mesh, mixing the three materials with a small amount of sodium polyacrylate and a pore-forming agent, adding 20% ​​water to mix evenly, and granulating into particles with a particle size of 1-2 mm, and then drying, sintering, and sieving to obtain the adsorption filtration filter material. The mass percentage ratio of the adsorption filter material of the adsorption filter material layer is: 40% of the processed crayfish shell, 25% of zeolite, 25% of rectorite, 5% of sodium polyacrylate, and 5% of pore-forming agent. A backwashing drain pipe valve 2-7 is provided at the end of the adsorption filter box water inlet pipe valve 2-3, a connecting pipe valve 2-8 is provided between the bottom of the adsorption filter storage tank 2-2 and the backwashing water distribution and air distribution space 2-4 at the bottom of the adsorption filter box 2-1, a bottom drain pipe valve 2-9 is provided in the backwashing water distribution and air distribution space 2-4, and a backwashing air pipe valve 2-10 is provided in the backwashing water distribution and air distribution space 2-4;

[0053] Centrifugal fan 3;

[0054] The air outlet 3-2 of the centrifugal fan 3 is connected to the backwash air pipe 1-8 and the backwash air pipe valve 2-10 respectively through the air delivery pipe valve 3-3.

[0055] A method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment comprises the following steps:

[0056] A1: Heavy metals and fluoride ions in lithium battery wet recovery wastewater are removed in the first stage by contact precipitation equipment 1, and then enter adsorption filtration equipment 2 for secondary deep removal through the submersible lifting pump 1-12, lifting pump outlet pipe 1-13 and adsorption filtration box inlet pipe 2-3 connected thereto, which are arranged at the bottom of the clear water tank 1-11 after precipitation;

[0057] A2: During the adsorption filtration treatment, the treated water enters the backwash water distribution and air distribution space 2-4 through the adsorption filtration box water inlet valve 2-3, the adsorption filtration filter material layer 2-61, the supporting layer 2-6, and the filter plate filter head assembly 2-5. The adsorption filtration water flows upward through the connecting pipe valve 2-8 into the adsorption filtration post-water storage tank 2-2, and finally flows out from the adsorption filtration post-water storage tank outlet channel 2-12 and the post-filtration water pipe 2-13 connected thereto for recycling or discharge in compliance with the standards;

[0058] A3: When the treated water passes through the adsorption filter layer 2-61, due to the special pores and open framework molecular structure inside the filter material, it can absorb a large amount of heavy metals and fluoride ions like a sponge and remove them. When the adsorption filter head through the adsorption filter layer 2-61 reaches the set value, backwashing is performed. When backwashing, first close the adsorption filter box water inlet pipe valve 2-3 and the connecting pipe valve 2-8, and open the bottom drain pipe valve 3-3 3min, drain part of the water from the backwashing water and air distribution space 2-4, lower the water level to 200mm above the surface of the adsorption filter material layer 2-61, open the top drainage valve 2-11 of the adsorption filter material layer, drain all the water above the top drainage valve 2-11 of the adsorption filter material layer, then open the backwashing air pipe valve 2-10 to backwash the adsorption filter material layer 2-61 for 18min, then open the connecting pipe valve 2-8 and the backwashing drainage pipe valve 2-7 for 4min, so that the water in the water tank 2-2 after adsorption filtration passes from bottom to top through the backwashing water and air distribution space 2-4, the filter plate and filter head assembly 2-5, and the supporting layer 2-6 to backwash the adsorption filter material layer 2-61;

[0059] A4: Finally, close the backwash drain valve 2-7, open the adsorption filter box water inlet valve 2-3 and restart the adsorption filtration. The backwash cycle is 48 hours. The adsorption filtration rate of the adsorption filter device 2 is 2m / h, the air flushing intensity is 12-16L / S·㎡, and the water flushing intensity is 3-4L / S·㎡. The air source for air and water flushing is supplied from the air outlet 3-2 of the centrifugal fan 3 through the backwash air pipe valve 2-10.

[0060] A5: After secondary treatment by the adsorption filtration filter material layer 2-61 of the adsorption filtration device 2, the heavy metals and fluoride ions in the lithium battery wet recovery wastewater can be reduced from low concentrations to the national standards for reclaimed water reuse or discharge.

[0061] The above are only exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any technician in the field without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention. It should also be noted that the various components of the present invention are not limited to the above-mentioned overall application. The various technical features described in the specification of the present invention can be selected one by one or multiple ones can be used in combination according to actual needs. Therefore, the present invention should naturally cover other combinations and specific applications related to the invention of this case.

Claims

1. A device for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment, characterized by: include: Contact precipitation equipment (1); The outer wall at the upper end of the contact sedimentation device (1) is connected to a contact sedimentation device water inlet pipe (1-1), and a guide area (1-2) is provided inside the contact sedimentation device (1). A support plate (1-3) is provided in the middle and lower part between the wall plate of the guide area (1-2) and the tail box wall. A cushion layer (1-4) is provided on the support plate (1-3). A contact material layer (1-5) is provided on the top surface of the cushion layer (1-4). A clean water area (1-6) is provided above the contact material layer (1-5). A recoil air is provided below the support plate (1-3). The contact sedimentation device (1) is provided with a sludge hopper (1-9) at the bottom, a sludge discharge pipe (1-10) is provided at the bottom of the sludge hopper (1-9), the contact sedimentation device (1) is provided with a post-sedimentation clean water tank (1-11), a water hole (1-7) is provided on the common wall of the contact sedimentation device (1) and the post-sedimentation clean water tank (1-11), a submersible lifting pump (1-12) is provided at the bottom of the post-sedimentation clean water tank (1-11), and a lifting pump outlet pipe (1-13) is provided in communication with the submersible lifting pump (1-12); Adsorption filtration equipment (2); The lower part of the adsorption filter device (2) is an adsorption filter box (2-1), and the upper part is an adsorption filter water storage tank (2-2), and the two are separated by a steel partition. The upper part of the adsorption filter box (2-1) is provided with an adsorption filter box water inlet pipe valve (2-3), and the adsorption filter box water inlet pipe valve (2-3) is connected to the lifting pump outlet pipe (1-3). The bottom plate of the adsorption filter box (2-1) and the bottom of the filter plate and filter head assembly (2-5) form a backwashing water distribution and air distribution space (2-4). The filter head and filter plate assembly (2-5) a supporting layer (2-6) is arranged on the top, a backwashing drainage pipe valve (2-7) is arranged at the end of the adsorption filter box water inlet pipe valve (2-3), a connecting pipe valve (2-8) is arranged between the bottom of the adsorption filter box (2-2) and the backwashing water distribution and air distribution space (2-4) at the bottom of the adsorption filter box (2-1), the backwashing water distribution and air distribution space (2-4) is provided with a bottom drainage pipe valve (2-9), and the backwashing water distribution and air distribution space (2-4) is provided with a backwashing air pipe valve (2-10); Centrifugal fan (3); The air outlet (3-2) of the centrifugal fan (3) is connected to the backwash air pipe (1-8) and the backwash air pipe valve (2-10) respectively via the air delivery pipe valve (3-3).

2. The device for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater according to claim 1, characterized in that: The contact sedimentation equipment (1) and the adsorption filtration equipment (2) both adopt an integrated housing and are made of anti-corrosion carbon steel.

3. The device for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater according to claim 1, characterized in that: The support plate (1-3) is made of anti-corrosion steel plate. The support plate (1-3) has holes, and the hole diameter is 15 mm, the hole spacing is 115 mm, and the support plate (1-3) is covered with a nylon mesh with a specification of 36 meshes / inch.

4. The device for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater according to claim 1, characterized in that: The cushion layer (1-4) is made of pebbles, the particle size of the pebbles is 16-25 mm, and the laying thickness is 100 mm.

5. The device for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater according to claim 1, characterized in that: The contact material layer (1-5) is a mixed material of 2-4 mm crayfish shells obtained by processing, crushing and screening, non-ionic polyacrylamide and polyferric chloride, and the laying thickness of the contact material layer (1-5) is 500 mm.

6. The device for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater according to claim 1, characterized in that: The filter plates of the filter plate and filter head assembly (2-5) are made of steel plates, and the size of a single filter plate is 980×980 (mm). At the same time, a hole is set on the single filter plate, and the hole diameter is 25 mm and the spacing is 125×125 (mm). An adjustable ABS long-handled filter head is installed on the hole.

7. The device for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater according to claim 1, characterized in that: The support layer (2-6) is made of quartz sand with a particle size of 2-4 (mm). The support layer (2-6) is 200 mm thick. An adsorption filter material layer (2-61) is arranged on the support layer (2-6). The adsorption filter material layer (2-61) is made of processed crayfish shells, zeolite, rectorite, etc., which are crushed to a particle size of less than 100 meshes, and then a small amount of sodium polyacrylate and a pore-forming agent are added to mix the dry powders, and then 20% of water is added to mix and granulate to form a particle size of 1-2 mm. The adsorption filter material layer (2-61) is 1500 mm thick. A drainage valve (2-11) is arranged on the top of the adsorption filter material layer (2-61). A water outlet channel (2-12) and a post-filtration water pipe (2-13) are arranged at the designed water level of the adsorption filter water storage tank (2-2).

8. The method for removing heavy metals and fluoride ions in the treatment of lithium battery wet recovery wastewater according to claims 1 to 7, characterized in that: The following steps are involved: S1: Lithium battery wet recovery wastewater enters the diversion area (1-2) through the contact sedimentation equipment water inlet pipe (1-1), bypasses the diversion plate, and enters the clean water area (1-6) through the support plate (1-3), the cushion layer (1-4), and the contact material layer (1-5); S2: entering the post-sedimentation clean water tank (1-11) through a water hole (1-7) provided on the common wall of the contact sedimentation device (1) and the post-sedimentation clean water tank (1-11); S3: entering the adsorption filter box (2-1) of the adsorption filter device (2) through the submersible lifting pump (1-12) and the lifting pump outlet pipe (1-13) arranged at the bottom of the clear water tank (1-11) after sedimentation and the adsorption filter box inlet pipe valve (2-3) connected thereto; S4: Most of the heavy metals and fluoride ions are precipitated and stored in the sludge hopper (1-9) after mud-water separation due to the chelating effect of the contact material of the contact material layer (1-5) on the heavy metal ions and the flocculation effect on the fluoride ions. In addition, a small part is retained in the contact material layer (1-5). In order to avoid excessive head loss caused by the accumulation of sludge containing heavy metals and fluoride ions in the contact material layer (1-5) during operation, a recoil air pipe (1-8) arranged under the support plate (1-3) is used to perform recoil at regular intervals. Flushing, the flushing cycle of regular backwashing is 7 days, the backwashing gas intensity is 15L / (S·㎡), the backwashing time is 2-3min, the backwashing gas source is supplied by the air outlet (3-2) of the centrifugal fan (3) through the air delivery pipe valve (3-3) and the backwashing air pipe (1-8) connected thereto, the sludge in the sludge hopper (1-9) is discharged through the sludge discharge pipe (1-10), and is recycled and recycled by a qualified unit, and the contact sedimentation time of the contact sedimentation equipment (1) is 20-30min; S5: After primary treatment by the contact material layer (1-5) of the contact precipitation device (1), the heavy metals and fluoride ions in the lithium battery wet recovery wastewater can be reduced from a medium concentration to a low concentration.

9. A method for removing heavy metals and fluoride ions in lithium battery wet recovery wastewater treatment according to claims 1 to 7, characterized in that: The following steps are involved: A1: Heavy metals and fluoride ions in lithium battery wet recovery wastewater are removed in the first stage by contact precipitation equipment (1), and then enter adsorption filtration equipment (2) for secondary deep removal through a submersible lifting pump (1-12) arranged at the bottom of the clear water tank (1-11) after precipitation, a lifting pump outlet pipe (1-13) and an adsorption filtration box inlet pipe (2-3) connected thereto; A2: During the adsorption filtration treatment, the treated water enters the backwash water distribution and air distribution space (2-4) through the adsorption filtration box water inlet valve (2-3), the adsorption filtration filter material layer (2-61), the support layer (2-6), and the filter plate and filter head assembly (2-5). The adsorption filtration effluent flows upward through the connecting pipe valve (2-8) into the adsorption filtration post-water storage tank (2-2), and finally flows out from the adsorption filtration post-water storage tank outlet channel (2-12) and the post-filtration water pipe (2-13) connected thereto for recycling or discharge in compliance with the standards; A3: When the treated water passes through the adsorption filter material layer (2-61), due to the special pores and open framework molecular structure inside the filter material, it can adsorb a large amount of heavy metals and fluoride ions like a sponge and remove them. When the adsorption filter head through the adsorption filter material layer (2-61) reaches the set value, backwashing is performed. During backwashing, the adsorption filter box water inlet pipe valve (2-3) and the connecting pipe valve (2-8) are first closed, and the bottom drain pipe valve (3-3) is opened for 3 minutes, and part of the water is discharged from the backwashing water and air distribution space (2-4) to reduce the water level to 200 above the surface of the adsorption filter material layer (2-61). mm, open the drainage valve (2-11) at the top of the adsorption filter material layer to drain the water above the drainage valve (2-11) at the top of the adsorption filter material layer, then open the backwash air pipe valve (2-10) to backwash the adsorption filter material layer (2-61) for 8 minutes, then open the connecting pipe valve (2-8) and the backwash drainage pipe valve (2-7) for 4 minutes, so that the water in the water storage tank (2-2) after adsorption filtration passes from bottom to top through the backwash water and air distribution space (2-4), the filter plate and filter head assembly (2-5), and the supporting layer (2-6) to backwash the adsorption filter material layer (2-61); A4: Finally, close the backwash drain pipe valve (2-7), open the adsorption filter box water inlet pipe valve (2-3) and restart the adsorption filtration. The backwash cycle is 48 hours. The adsorption filtration rate of the adsorption filtration equipment (2) is 2m / h, the air flushing intensity is 12-16L / (S·㎡), and the water flushing intensity is 3-4L / (S·㎡). The air source for air and water flushing is supplied from the air outlet (3-2) of the centrifugal fan (3) through the backwash air pipe valve (2-10); A5: After secondary treatment by the adsorption filtration filter material layer (2-61) of the adsorption filtration device (2), the heavy metals and fluoride ions in the lithium battery wet recovery wastewater can be reduced from low concentrations to the relevant national standards for reclaimed water reuse or discharge.

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