A multi-stage cleaning and sorting method for lead grids of waste lead-acid batteries

Abstract

The present invention relates to the technical field of waste lead-acid battery processing, and specifically to a multi-stage cleaning and sorting method for waste lead-acid battery lead grids, comprising: Step 1: crushing the waste lead-acid battery material to be processed, thereby crushing the waste lead-acid battery into crushed material, wherein the crushed material includes lead grids, plastic, separator paper, and lead mud; Step 2: performing a first high-pressure water rinse on the lead grids, wherein the crushed material in Step 1 is high-pressure rinsed through a lead paste separation screen to extract the lead grids, separator paper, and plastic from the crushed material. The multi-stage cleaning and sorting method for waste lead-acid battery lead grids of the present invention can achieve centralized recovery of most small pieces of lead grid, improve the quality of the lead grid raw materials entering the lead grid low-temperature smelting system, reduce smelting energy and labor consumption, and further increase the lead grid recovery rate.

Description

Technical Field

[0001] The present invention relates to the technical field of waste lead-acid battery treatment, and in particular to a multi-stage cleaning and sorting method for lead grids of waste lead-acid batteries. Background Art

[0002] Scrap lead-acid batteries contain large amounts of lead and acid. If improperly handled, they can cause serious pollution to the atmosphere, soil, and water sources. Illegal dismantling and smelting have resulted in large quantities of scrap lead-acid batteries entering illegal channels, polluting the environment and endangering health.

[0003] The positive electrode of a lead-acid battery primarily consists of lead dioxide, while the negative electrode primarily consists of lead grid. Currently, similar equipment, both domestically and internationally, utilizes a "bipolar lead grid gravity separation system" for extracting lead grid from scrap lead-acid batteries. This system uses two separate air-water separation processes, allowing the lead grid to settle to the bottom for extraction via a screw conveyor. Due to the limited separation volume, even with the air-water separation, the lead grid cannot be quickly separated from the separator paper. Small pieces of lead grid are carried away by the separator paper, resulting in reduced lead grid recovery rates and increased impurity levels, leading to significant waste. This situation is particularly exacerbated at processing rates exceeding 50 tons per hour. The water within the grid screws cannot be dynamically circulated, leading to a continuous increase in lead sludge content. This results in lead paste being carried over the lead grid surface during separation, significantly harming the environment. Furthermore, the high concentration of small lead grid fragments prevents them from effectively producing crude lead when entering the low-temperature melting and casting system. Instead, these fragments become lead oxide slag, requiring further smelting in the furnace. This repeated smelting process wastes energy and labor. Summary of the Invention

[0004] In view of this, the present invention provides a multi-stage cleaning and sorting method for scrap lead-acid battery lead grids, which can realize the centralized recovery of most small pieces of lead grids, improve the quality of lead grid raw materials entering the lead grid low-temperature smelting and casting system, reduce the consumption of smelting energy and labor, and further improve the recovery rate of lead grids.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] The present invention provides a multi-stage cleaning and sorting method for lead grids of waste lead-acid batteries, comprising:

[0007] Step 1: Crushing the waste lead-acid batteries, crushing the waste lead-acid batteries to be processed into crushed materials, wherein the crushed materials include lead grids, plastics, separator paper and lead mud;

[0008] Step 2: The lead grid is washed with high-pressure water for the first time. The crushed material in step 1 is washed with high pressure through the lead paste separation screen to extract the lead grid, separator paper and plastic from the crushed material;

[0009] Step 3: The lead grid undergoes the first hydrodynamic separation. The lead grid, plastic, and separator paper extracted in Step 2 are conveyed to the primary hydrodynamic separator. Under the action of specific gravity, water flow, and air flow, the lead grid settles to the bottom of the primary hydrodynamic separator and is discharged by the first lead grid extraction screw conveyor. The separator paper and small pieces of lead grid enter the first return water pipe.

[0010] Step 4: The lead grid undergoes a second hydrodynamic separation. The first lead grid extraction screw conveyor conveys the lead grid and some separator paper to the secondary hydrodynamic separator. Under the action of specific gravity, water flow, and air flow, the lead grid and separator paper are further separated. The lead grid settles to the bottom of the secondary hydrodynamic separator and is discharged by the second lead grid cleaning screw conveyor. The separator paper and small pieces of lead grid enter the second return water pipe.

[0011] Step 5: The lead grid is cleaned once. The lead grid separated in step 4 is conveyed into the flushing water pipe for flushing under the action of the second lead grid cleaning screw conveyor. The lead mud water in the second lead grid cleaning screw conveyor overflows into the third return pipe.

[0012] Step 6: Secondary cleaning of the lead grid. The lead grid that has been rinsed in the flushing water pipe is transported to the drum cleaning screen. The drum cleaning screen performs secondary cleaning on the lead grid. The lead mud and small pieces of lead grid on the surface of the lead grid leak through the screen of the drum cleaning screen into the fourth return water pipe. The clean large pieces of lead grid are discharged from the tail of the drum cleaning screen and sent to the external low-temperature melting and casting system for smelting.

[0013] Step 7: separation of small lead grids. The reflux water, small lead grids, separator paper, etc. generated in steps 3, 4, 5, and 6 are collected into the small lead grid settling device through the reflux pipe. Under the action of the small lead grid settling device, the small lead grids are separated and transported to the external low-temperature melting and casting system for smelting.

[0014] As an improvement: the step 3 further includes: in the first-stage hydrodynamic separator, under the action of specific gravity and water flow and air flow dynamics, the plastic is separated into a plastic collection bin.

[0015] As an improvement: Step 7 also includes: under the action of the small lead grid sedimentation device, the return water and separator paper are transported to the dewatering screen through the pipeline, the separator paper is discharged from the material outlet of the dewatering screen, and the return water leaks through the screen into the circulating water tank.

[0016] As an improvement, the return water in the circulating water tank is resupplied to the primary hydrodynamic separator, the secondary hydrodynamic separator, the flushing water pipeline and the drum cleaning screen.

[0017] As an improvement, the circulating water in the first lead grid extraction screw conveyor enters the secondary hydrodynamic separator to realize water circulation in the first lead grid extraction screw conveyor.

[0018] In summary, the present invention has the following technical effects:

[0019] 1. The present invention can fully recover the lead grid produced after disassembly by subjecting the lead grid to multiple hydrodynamic separations and high-pressure water cleanings, and improve the quality of the lead grid for the subsequent low-temperature lead grid casting system;

[0020] 2. It realizes the separation of small pieces of lead grid, improves the recovery rate of small pieces of lead grid, and realizes the direct recovery of small pieces of lead grid, avoiding the problem of small pieces of lead grid entering the low-temperature smelting system and becoming lead oxide slag and then being repeatedly smelted;

[0021] 3. The reflux water in the separation and crushing process contains acid. The reflux water is used to provide high-pressure water flushing for the sorting steps, which improves the lead grid sorting rate and reduces the mutual mixing rate of material sorting. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0023] Figure 1 A schematic diagram of the connection relationship between various devices in the method; DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0025] The exemplary embodiments of the present invention are described below with reference to specific situations:

[0026] Please refer to Figure 1 The present invention provides a multi-stage cleaning and sorting method for lead grids of waste lead-acid batteries, comprising:

[0027] Step 1: Crushing the waste lead-acid batteries. Crushing the waste lead-acid batteries to be processed into crushed materials, including lead grids, plastics, separator paper and lead mud.

[0028] Step 2: The lead grid is washed with high-pressure water for the first time. The crushed material in step 1 is washed with high pressure through the lead paste separation screen to extract the lead grid, separator paper and plastic from the crushed material;

[0029] Step 3: The lead grid undergoes the first hydrodynamic separation. The lead grid, plastic, and separator paper extracted in Step 2 are conveyed to the primary hydrodynamic separator. Under the action of specific gravity, water flow, and air flow, the lead grid settles to the bottom of the primary hydrodynamic separator and is discharged by the first lead grid extraction screw conveyor. The separator paper and small pieces of lead grid enter the first return water pipe.

[0030] In this step, the lead grid and the separator paper cannot be completely separated. Therefore, when the first lead grid extraction screw conveyor outputs, the lead grid will be mixed with a certain amount of separator paper and transported to the secondary hydrodynamic separator, while the remaining separator paper and small pieces of lead grid enter the first return water pipe and are transported to the small lead grid sedimentation device, which is the existing technology.

[0031] Step 4: The lead grid undergoes a second hydrodynamic separation. The first lead grid extraction screw conveyor conveys the lead grid and some separator paper to the secondary hydrodynamic separator. Under the action of specific gravity, water flow, and air flow, the lead grid and separator paper are further separated. The lead grid settles to the bottom of the secondary hydrodynamic separator and is discharged by the second lead grid cleaning screw conveyor. The separator paper and small pieces of lead grid enter the second return water pipe. The second return pipe conveys the separator paper and small pieces of lead grid produced in this step to the small lead grid settling device.

[0032] Step 5: The lead grid is cleaned once. The lead grid separated in step 4 is transported into the flushing water pipe for flushing under the action of the second lead grid cleaning screw conveyor;

[0033] In step 5, an overflow port is provided at a suitable position on the spiral housing of the second lead grid cleaning screw conveyor, and a height-adjustable baffle is provided at the overflow port to enable circulation of lead sludge water inside the lead grid cleaning screw conveyor, so that the lead sludge water in the second lead grid cleaning screw conveyor overflows into the third return pipe. The second return pipe conveys the lead sludge water produced in this step to the small lead grid settling device;

[0034] Step 6: Secondary cleaning of the lead grid. The lead grid that has been rinsed in the flushing water pipe is transported to the drum cleaning screen. The drum cleaning screen performs secondary cleaning on the lead grid. The lead mud and small pieces of lead grid on the surface of the lead grid leak through the screen of the drum cleaning screen into the fourth return water pipe. The clean large pieces of lead grid are discharged from the tail of the drum cleaning screen and sent to the external low-temperature melting and casting system for smelting.

[0035] In step 6, the screen gap of the drum cleaning screen is 0.7 mm, and a high-pressure nozzle is set in the screen to clean the lead grid with high-pressure water. The fourth return water pipe transports the lead mud and small pieces of lead grid to the small piece of lead grid sedimentation device;

[0036] Step 7: separation of small lead grids. The reflux water, small lead grids, separator paper, etc. generated in steps 3, 4, 5, and 6 are collected into the small lead grid settling device through the reflux pipe. Under the action of the small lead grid settling device, the small lead grids are separated and transported to the external low-temperature melting and casting system for smelting.

[0037] The present invention subjects the lead grid to multiple hydrodynamic separations and high-pressure water cleanings, thereby fully recovering the lead grid produced after disassembly, improving the quality of the lead grid for a subsequent low-temperature lead grid smelting and casting system, achieving separation of small pieces of lead grid, improving the recovery rate of small pieces of lead grid, and realizing direct recovery of small pieces of lead grid, thereby avoiding the problem of small pieces of lead grid entering a low-temperature smelting system and becoming lead oxide slag, which is then repeatedly smelted.

[0038] In this embodiment, in the first-stage hydrodynamic separator, the plastic is separated into a plastic collection bin under the action of specific gravity and the dynamics of water and air flow.

[0039] In this embodiment, a screen is installed within the small lead grid settling device. When the return water passes through this device, the flow rate decreases. The heavier small lead grids in the material settle and fall through the bottom screen into the collection hopper and are output by the conveying screw at the bottom, resulting in small lead grids. The return water continues to flow downward. Under the action of the small lead grid settling device, the return water and separator paper are transported to the dewatering screen through a pipe. The separator paper is discharged from the material outlet of the dewatering screen, and the return water leaks through the screen into the circulating water tank. The return water in the circulating water tank is re-supplied to the primary hydrodynamic separator, the secondary hydrodynamic separator, the flushing water pipeline, and the drum cleaning screen. The return water in the separation and crushing process contains acid. Using the return water to provide high-pressure water flushing for the sorting and other steps improves the lead grid sorting rate and reduces the mutual mixing rate of the material sorting.

[0040] In this embodiment, by reasonably setting the outlet of the first lead grid extraction screw conveyor and connecting a corresponding flushing water pipe at the tail of the first lead grid extraction screw conveyor, the circulating water in the first lead grid extraction screw conveyor can enter the secondary hydrodynamic separator, realizing water circulation in the first lead grid extraction screw conveyor, thereby improving the water quality in the first lead grid extraction screw conveyor.

[0041] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0042] The above is a detailed introduction to the specific implementation methods provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A multi-stage cleaning and sorting method for lead grids of waste lead-acid batteries, characterized in that: Includes: Step 1: Crushing the waste lead-acid batteries, crushing the waste lead-acid batteries to be processed into crushed materials, wherein the crushed materials include lead grids, plastics, separator paper and lead mud; Step 2: The lead grid is washed with high-pressure water for the first time. The crushed material in step 1 is washed with high pressure through the lead paste separation screen to extract the lead grid, separator paper and plastic from the crushed material; Step 3: The lead grid undergoes the first hydrodynamic separation. The lead grid, plastic, and separator paper extracted in Step 2 are conveyed to the primary hydrodynamic separator. Under the action of specific gravity, water flow, and air flow, the lead grid settles to the bottom of the primary hydrodynamic separator and is discharged by the first lead grid extraction screw conveyor. The separator paper and small pieces of lead grid enter the first return water pipe. Step 4: The lead grid undergoes a second hydrodynamic separation. The first lead grid extraction screw conveyor conveys the lead grid and some separator paper to the secondary hydrodynamic separator. Under the action of specific gravity, water flow, and air flow, the lead grid and separator paper are further separated. The lead grid settles to the bottom of the secondary hydrodynamic separator and is discharged by the second lead grid cleaning screw conveyor. The separator paper and small pieces of lead grid enter the second return water pipe. Step 5: The lead grid is cleaned once. The lead grid separated in step 4 is conveyed into the flushing water pipe for flushing under the action of the second lead grid cleaning screw conveyor. The lead mud water in the second lead grid cleaning screw conveyor overflows into the third return pipe. Step 6: Secondary cleaning of the lead grid. The lead grid that has been rinsed in the flushing water pipe is transported to the drum cleaning screen. The drum cleaning screen performs secondary cleaning on the lead grid. The lead mud and small pieces of lead grid on the surface of the lead grid leak through the screen of the drum cleaning screen into the fourth return water pipe. The clean large pieces of lead grid are discharged from the tail of the drum cleaning screen and sent to the external low-temperature melting and casting system for smelting. Step 7: separation of small lead grids. The reflux water, small lead grids, separator paper, etc. generated in steps 3, 4, 5, and 6 are collected into the small lead grid settling device through the reflux pipe. Under the action of the small lead grid settling device, the small lead grids are separated and transported to the external low-temperature melting and casting system for smelting.

2. The multi-stage cleaning and sorting method for waste lead-acid battery lead grids according to claim 1, wherein: The step 3 further includes: in the first-stage hydrodynamic separator, under the action of specific gravity and water flow and air flow dynamics, the plastic is separated into a plastic collection bin.

3. The multi-stage cleaning and sorting method for waste lead-acid battery lead grids according to claim 1, characterized in that: The step 7 also includes: under the action of the small lead grid sedimentation device, the return water and the separator paper are transported to the dewatering screen through the pipeline, the separator paper is discharged from the material outlet of the dewatering screen, and the return water leaks through the screen into the circulating water tank.

4. The multi-stage cleaning and sorting method for waste lead-acid battery lead grids according to claim 3, characterized in that: The return water in the circulating water tank is resupplied to the primary hydrodynamic separator, the secondary hydrodynamic separator, the flushing water pipeline and the drum cleaning screen.

5. The multi-stage cleaning and sorting method for waste lead-acid battery lead grids according to claim 1, characterized in that: The circulating water in the first lead grid extraction screw conveyor enters the secondary hydrodynamic separator, thereby realizing the water circulation in the first lead grid extraction screw conveyor.

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