CN110611137A - A dry recovery method for waste power lithium batteries - Google Patents

Abstract

The invention relates to a dry recovery method for waste power lithium batteries, comprising S1, crushing the cells of waste power lithium batteries by shearing and crushing, to obtain electrode scraps and separators; S2, performing high-temperature treatment on the electrode scraps , remove the binder, and grind with a stirring mill to obtain electrode powder and copper-aluminum mixture; S3, conduct airflow sorting on electrode powder, copper-aluminum mixture and diaphragm to obtain electrode powder, diaphragm mixture and copper-aluminum mixture respectively; S4 , classifying the electrode powder and separator mixture to obtain electrode powder and separator; S5, performing secondary classification on the copper-aluminum mixture to obtain copper foil and aluminum foil. The invention provides a complete pretreatment route for waste power lithium batteries, classifies and recycles copper foil, aluminum foil, diaphragm and electrode powder, and applies dry methods to effectively reduce environmental pollution, and reduce subsequent processing pressure while recycling resources , is a resource-based, harmless pretreatment process.

Description

A dry recovery method for waste power lithium batteries

technical field

The invention relates to the field of solid waste recovery and treatment, in particular to a dry recovery method for waste power lithium batteries.

Background technique

Lithium batteries have the characteristics of high working voltage, high energy density, long cycle life, good safety performance, clean and pollution-free, and are widely used in important fields such as transportation, electric power, mobile communications, new energy storage, and aerospace military industry. With the popularization and promotion of new energy vehicles, lithium batteries shine even more in the field of energy storage for new energy vehicles. Due to the high energy consumption and short service life of power lithium batteries, the amount of scrapping has increased sharply, causing serious pollution to the environment. At the same time, waste power lithium batteries contain a large amount of resources such as copper, aluminum, graphite, etc., and if they are not recycled effectively, resources will also be wasted. . Therefore, the recycling of waste power lithium batteries is imminent.

However, the recycling of waste power lithium batteries in my country is currently in the laboratory stage, which is mainly divided into two parts: pretreatment and follow-up treatment. The optimization of pretreatment can reduce the pressure of follow-up treatment. At present, there is no complete recycling and harmless treatment in China. pretreatment process.

Contents of the invention

The invention designs a dry recovery method for waste power lithium batteries, which solves the problems of low recovery rate, environmental pollution and high energy consumption of waste power lithium batteries in the existing pretreatment technology.

In order to solve the above-mentioned technical problems, the present invention adopts the following scheme:

A dry recovery method for waste power lithium batteries, comprising the following steps:

S1, crushing the battery cells of the waste power lithium battery by shearing and crushing to obtain electrode scraps and separators;

S2, subjecting the electrode scraps to high-temperature treatment, removing the binder, and grinding with a stirring mill to obtain electrode powder and a copper-aluminum mixture;

S3, performing airflow sorting on the electrode powder, the copper-aluminum mixture, and the separator obtained in S1 to obtain the electrode powder, the separator mixture, and the copper-aluminum mixture respectively;

S4, classifying the electrode powder and separator mixture to obtain electrode powder and separator;

S5, performing secondary classification on the copper-aluminum mixture to obtain copper foil and aluminum foil.

There is no sequence between step S4 and step S5.

Preferably, in the step S1, the crushing method is shear crushing, so as to ensure the shape of the crushed material.

Preferably, in the step S2, the high-temperature treatment to remove the binder should be carried out under ventilated conditions to ensure that the organic binder undergoes a cracking reaction to obtain the cracked gas and the electrode powder.

In step S2, the step of removing the binder from the electrode scrap at high temperature includes: covering the container with the electrode scrap, and volatilizing the binder at high temperature under ventilated conditions to obtain electrode powder and a copper-aluminum mixture.

Preferably, in the step S2, the temperature of the high temperature treatment is 400-500°C; the time of the high temperature treatment is 1-2h.

Preferably, in the step S2, the grinding medium used in the stirring mill is quartz sand with a particle size of 3-6mm, and the filling rate of the medium is greater than 50%.

Preferably, the step S2 further includes a flue gas purification treatment process, the flue gas purification treatment process processes the flue gas generated by the high temperature treatment.

Preferably, in the step S3, a variable-diameter pulsating airflow separator is used for primary airflow separation of the electrode powder, copper-aluminum mixture, and separator;

Preferably, the air volume of the variable-diameter pulsating airflow separator should be 40-50m ³ /h;

Preferably, the cone ratio of the variable-diameter section of the variable-diameter pulsating airflow separator should be 1/25-4/25;

Preferably, the height of the straight section of the variable-diameter pulsating airflow separator should be 0.5-1m;

Preferably, the ratio of the internal diameter of the discharge opening of the gas distributor to the cross-sectional area of the sorting column of the variable-diameter pulsating airflow separator should be 15%-20%.

Specifically, in step S3, the step of using a variable-diameter pulsating airflow separation device to conduct airflow separation of the electrode powder, copper-aluminum mixture, and diaphragm includes: putting the materials into the feeder, adjusting the air volume of the airflow separation machine to 40-50m ³ /h, the feeder evenly feeds the material, and obtains the electrode powder and separator mixture and copper-aluminum mixture.

In step S3, the primary airflow sorting process also includes the step of performing dust removal treatment on the sorting equipment.

Preferably, in the step S4, the mixture of the electrode powder and the separator is classified by using a cyclone separator. When grading the mixture of electrode powder and diaphragm, the air volume of grading should be constant, and a dust removal device should be used at the same time.

Preferably, in the step S5, a variable-diameter pulsating airflow separator is used for secondary airflow separation of the copper-aluminum mixture;

Preferably, the air volume of the variable-diameter pulsating airflow separator should be 120-150m ³ /h;

Preferably, the cone ratio of the variable-diameter section of the variable-diameter pulsating airflow separator should be 1/25-4/25;

Preferably, the height of the straight section of the variable-diameter pulsating airflow separator should be 0.5-1m;

Preferably, the ratio of the internal diameter of the discharge opening of the gas distributor to the cross-sectional area of the sorting column of the variable-diameter pulsating airflow separator should be 15%-20%.

Specifically, in step S5, the step of using a variable-diameter pulsating airflow separation device to carry out secondary airflow separation of the copper-aluminum mixture includes: the heavy product of the primary airflow separation is a copper-aluminum mixture, which enters the secondary airflow separation equipment During the process, adjust the air volume of the classifier to 120-150m ³ /h to obtain copper foil and aluminum foil.

Preferably, in the step S1, before the electric core is cut into pieces, it also includes performing a deep discharge process on the waste power lithium battery.

The dry recovery method of waste power lithium batteries has the following beneficial effects:

(1) The present invention provides a complete pretreatment route for waste power lithium batteries, and effectively classifies and recycles the metal resources (copper, aluminum), diaphragm and electrode powder in it, and does not produce any pollution during the treatment process, It is a resourceful, green and environmentally friendly pretreatment process for waste power lithium batteries. In addition, the above-mentioned pretreatment process has the characteristics of simple structure, easy operation, etc., and is easy to realize industrialization and large-scale, and is very suitable for large-scale industrial application.

(2) The present invention recycles waste power lithium batteries, and some volatile organic compounds will be produced when the batteries are broken. When this part of the flue gas and the volatile organic matter produced in the crushing process are ignited and added with quicklime, the acidic gas containing fluorine and phosphorus is converted into calcium fluoride and calcium phosphate to achieve harmless treatment. .

(3) The electrode scraps in the present invention are treated at high temperature, and the remaining solid matter is mainly a mixture of copper foil, aluminum foil, electrode powder and diaphragm, and enters the main separation equipment. In addition, the crushing method adopted in the present invention is shear crushing, so that the shape after crushing is guaranteed, and the particle size is relatively large, which is beneficial to subsequent sorting. Secondly, according to the density difference and particle size difference of copper foil, aluminum foil, separator and electrode powder, it realizes sorting by density and grading by particle size, and realizes the sorting-grading integrated process of sorting out 4 kinds of products in one feeding. The copper foil and aluminum foil produced can be reused after further treatment.

Description of drawings

Figure 1: Schematic diagram of the dry recovery pretreatment process of waste power lithium batteries according to the present invention;

Figure 2: Schematic diagram of the waste power lithium battery dry recovery system of the present invention;

Explanation of reference signs:

10—shearing and crushing device; 20—high temperature roasting device; 30—flue gas purification device; 40—dry recovery system for waste power lithium battery; 41—primary air flow separator; 42—secondary air flow separator; 43— primary classifier; 50—discharging device.

Detailed ways

Below in conjunction with Fig. 1 to Fig. 2, the present invention will be further described:

As shown in Figure 1, if a large number of waste power lithium batteries in the market are not properly treated, it will restrict the development of society. The current treatment technology has the problems of low recovery efficiency, high treatment pressure, and serious environmental pollution. Aiming at this problem, the present invention provides a dry recovery method for waste power lithium batteries, which includes the following steps: S1, crushing the battery cells by shearing and crushing to obtain electrode scraps and diaphragms; S2, crushing the electrode scraps The material is subjected to high-temperature treatment, the binder is removed, and the electrode powder and the copper-aluminum mixture are obtained by grinding with a stirring mill; S3, the electrode powder, the copper-aluminum mixture and the diaphragm are subjected to airflow separation by a variable-diameter pulsating airflow separation device to obtain Electrode powder and separator mixture and copper-aluminum mixture; S4, classify the mixture of electrode powder and separator to obtain electrode powder and separator; S5, use variable-diameter pulsating airflow separation device to separate copper-aluminum mixture by secondary airflow, Get copper foil and aluminum foil.

Using the above treatment system to recycle waste power lithium batteries, some volatile organic compounds will be produced when the battery cells are crushed. When the electrode scraps are subjected to high temperature removal of binders, since the binders are organic substances, when the temperature reaches 400-500°C , will make it volatilize and produce flue gas. This part of the flue gas and the volatile organic matter produced in the crushing process are ignited and added with quicklime to convert the acid gas containing fluorine and phosphorus into calcium fluoride and calcium phosphate, realizing harmless treatment. The electrode scraps in the present invention are treated at high temperature, and the remaining solid matter is mainly a mixture of copper foil, aluminum foil, electrode powder and diaphragm, and enters the main separation equipment. In addition, the crushing method adopted in the present invention is shear crushing, so that the shape after crushing is guaranteed, and the particle size is relatively large, which is beneficial to subsequent sorting. Secondly, according to the density difference and particle size difference of copper foil, aluminum foil, separator and electrode powder, it realizes sorting by density and grading by particle size, and realizes the sorting-grading integrated process of sorting out 4 kinds of products in one feeding. The output copper foil and aluminum foil can be reused after simple treatment. The invention provides a complete pretreatment route for waste power lithium batteries, and effectively classifies and recycles the metal resources (copper, aluminum), diaphragm and electrode powder in it, and does not produce any pollution during the treatment process. Recycling of power lithium batteries, green and environmentally friendly pretreatment process. In addition, the above-mentioned pretreatment process has the characteristics of simple structure, easy operation, etc., and is easy to realize industrialization and large-scale, and is very suitable for large-scale industrial application.

The crushing process adopts the shear crushing method. In order to ensure the safety of the crushing process, the crushing process should be under the protection of inert gas, and the crushing temperature should be kept below 20°C.

In order to improve the efficiency of high-temperature roasting to remove the binder, and to ensure that the electrode powder does not undergo redox reactions during the heating process, the roasting temperature should be 400-500 ° C, and the ventilation conditions must be good, and the roasting time should be 1-2 hours. The roasted organic volatiles are discharged after being treated by the flue gas purification device.

After the above process, the remaining solid mixture enters the waste power lithium battery dry recovery system.

Through a sorting system, the mixture is divided into two parts: copper foil, aluminum foil mixture, electrode powder and separator mixture. Preferably, the air volume in this process should be controlled at 40-50m ³ /h, and a bag dust removal device should be installed at the light product discharge end.

After the above sorting process is completed, light products (electrode powder, separator mixture) enter the primary classification system and are divided into two parts: electrode powder and separator. The classification system is equipped with a complete dust removal system.

The heavy product (copper foil, aluminum foil mixture) enters the secondary separation system and is divided into light product aluminum foil and heavy product copper foil.

Preferably, the air volume in this process should be controlled at 120-150m ³ /h, and a bag dust removal device should be installed at the light product discharge end.

In step S3 and step S5, the primary and secondary separation devices adopt a variable-diameter pulsating airflow separation machine. Preferably, the cone ratio of the variable-diameter section of the variable-diameter pulsating airflow separator should be 1/25-4/25.

In step S3 and step S5, the primary and secondary separation devices adopt a variable-diameter pulsating airflow separation machine. Preferably, the height of the straight section of the variable-diameter pulsating airflow separator should be 0.5-1m.

In step S3 and step S5, the primary and secondary separation devices adopt a variable-diameter pulsating airflow separation machine. Preferably, the ratio of the internal diameter of the discharge opening of the gas distributor of the variable-diameter pulsating airflow separator to the cross-sectional area of the separation column should be 15%-20%.

In step S4, the classifying device adopts a cyclone separator.

As shown in Figure 2, a kind of waste power lithium battery dry recovery system 40 comprises primary airflow sorter 41, secondary airflow sorter 42 and primary classifier 43; primary airflow sorter 41 separates electrode powder and copper The aluminum mixture and the separator are subjected to primary airflow separation to obtain electrode powder, separator mixture, and copper-aluminum mixture respectively; the secondary airflow separator 42 performs secondary separation of the copper-aluminum mixture to obtain copper foil and aluminum foil; the primary classifier 43 will The mixture of electrode powder and separator is classified to obtain electrode powder and separator.

It also includes a high-temperature roasting device 20, which performs high-temperature treatment on the electrode scraps, removes the binder, and grinds them with a stirring mill to obtain electrode powder and a copper-aluminum mixture.

A flue gas purification device 30 is also included, and the flue gas purification device 30 processes the flue gas generated by the high temperature roasting device 20 .

It also includes a shearing and crushing device 10, which crushes the batteries of waste power lithium batteries by shearing and crushing to obtain electrode scraps and separators.

It also includes a discharge device 50, which performs a deep discharge process on the waste power lithium battery before the battery core is sheared and broken.

Above, the present invention has been exemplarily described in conjunction with the accompanying drawings. Obviously, the realization of the present invention is not limited by the above-mentioned manner, as long as various improvements of the method concept and technical solutions of the present invention are adopted, or the present invention is implemented without improvement. The ideas and technical schemes directly applied to other occasions are within the protection scope of the present invention.

Claims (10)

1. A dry recovery method for waste power lithium batteries, comprising the following steps: S1, crushing the battery cells of the waste power lithium battery by shearing and crushing to obtain electrode scraps and separators; S2, subjecting the electrode scraps to high-temperature treatment, removing the binder, and grinding with a stirring mill to obtain electrode powder and a copper-aluminum mixture; S3, performing airflow sorting on the electrode powder, the copper-aluminum mixture, and the separator obtained in S1 to obtain the electrode powder, the separator mixture, and the copper-aluminum mixture respectively; S4, classifying the electrode powder and separator mixture to obtain electrode powder and separator; S5, performing secondary classification on the copper-aluminum mixture to obtain copper foil and aluminum foil. 2. The dry recovery method of waste power lithium batteries according to claim 1, characterized in that: in the step S1, the crushing method is shear crushing to ensure the shape of the crushed material. 3. The dry recovery method of waste power lithium batteries according to claim 1, characterized in that: in the step S2, the high-temperature treatment is used to remove the binder, which should be carried out under ventilated conditions to ensure organic The binder undergoes cracking reaction to obtain the cracked gas and the electrode powder. 4. The dry recovery method of waste power lithium batteries according to claim 2, characterized in that: in the step S2, the temperature of the high temperature treatment is 400-500°C; the time of the high temperature treatment is 1-2h. 5. The dry recovery method of waste power lithium batteries according to claim 3 or 4, characterized in that: in the step S2, the grinding medium used in the stirring mill is quartz sand with a particle size of 3-6mm, and the medium is filled with The rate is greater than 50%. 6. The method for dry recovery of waste power lithium batteries according to claim 3, 4 or 5, characterized in that: said step S2 also includes a flue gas purification treatment process, and said flue gas purification treatment process treats the high temperature Dispose of generated fumes. 7. The method for dry recovery of waste power lithium batteries according to claim 1, characterized in that, in the step S3, a variable-diameter pulsating airflow is used for primary airflow separation of the electrode powder, copper-aluminum mixture, and diaphragm Sorting machine; Preferably, the air volume of the variable-diameter pulsating airflow separator should be 40-50m ³ /h; Preferably, the cone ratio of the variable-diameter section of the variable-diameter pulsating airflow separator should be 1/25-4/25; Preferably, the height of the straight section of the variable-diameter pulsating airflow separator should be 0.5-1m; Preferably, the ratio of the internal diameter of the discharge opening of the gas distributor to the cross-sectional area of the sorting column of the variable-diameter pulsating airflow separator should be 15%-20%. 8. The dry recovery method of waste power lithium batteries according to claim 1, characterized in that, in the step S4, the mixture of the electrode powder and the separator is classified and treated by using a cyclone separator. 9. The dry recovery method of waste power lithium batteries according to claim 1, characterized in that, in the step S5, a variable-diameter pulsating airflow separator is used for secondary airflow separation of the copper-aluminum mixture; Preferably, the air volume of the variable-diameter pulsating airflow separator should be 120-150m ³ /h; Preferably, the cone ratio of the variable-diameter section of the variable-diameter pulsating airflow separator should be 1/25-4/25; Preferably, the height of the straight section of the variable-diameter pulsating airflow separator should be 0.5-1m; Preferably, the ratio of the internal diameter of the discharge opening of the gas distributor to the cross-sectional area of the sorting column of the variable-diameter pulsating airflow separator should be 15%-20%. 10. The dry recovery method of waste power lithium batteries according to any one of claims 1 to 9, characterized in that, in the step S1, before cutting and crushing the battery cells, it also includes retrieving waste power lithium batteries Perform a deep discharge process.