CN108654855A - A kind of recovery method of waste and old lithium ion battery - Google Patents

Abstract

The invention discloses a recovery method of waste lithium ion batteries, and relates to the field of comprehensive recovery and utilization of waste batteries. The method is used to solve the problem in the prior art that the recovery process of the lithium-ion battery is complicated, and a large amount of waste water or organic solvent is generated, which easily causes environmental pollution. Including: smashing the lithium-ion battery into fragments with a diameter of 10-100 mm; transporting the fragments to the cyclone separator through the fan, and determining the fragments falling into the ash collecting bucket at the bottom of the cyclone separator as the first fragment; The first fragment is crushed into particles with a particle size between 10-200 μm, and the particles are transported to the cyclone separator according to the wind speed set by the fan, and the particles with the first density in the particles fall into the ash collecting hopper through the cyclone separator, Particles having a second density among the particles are discharged through the top discharge of the cyclone separator; the first density being greater than the second density.

Description

A kind of recycling method of waste lithium ion battery

technical field

The invention relates to the field of comprehensive recycling of waste batteries, in particular to a method for recycling waste lithium ion batteries.

Background technique

Due to the popularization of portable electronic products such as notebook computers and mobile phones, the consumption of lithium-ion batteries is increasing day by day. Moreover, in recent years, urban air pollution has continued to worsen. The national, provincial and municipal departments at all levels have vigorously promoted new energy vehicles. The volume exceeds 5 million vehicles. Since the capacity of lithium-ion batteries will gradually decay with the process of charging and discharging, once the capacity is lower than people's expected capacity, it will be discarded. valuable metal resources. In addition, if the lithium-ion battery is directly buried, once the heavy metals such as Co and Ni leak out, it will pollute the soil and groundwater. Therefore, recycling waste lithium-ion batteries has huge economic value and environmental protection value.

At present, the research methods for the recycling of lithium-ion batteries mainly include low-temperature freezing and crushing, solvent method, acid-base solution method, ultrasonic method, and roasting method. Although these methods can recover high-purity electrode materials, the production process is complicated, and a large amount of waste water or organic solvents will be generated, which will cause a huge burden on the environment.

Contents of the invention

The embodiments of the present invention provide a method for recycling waste lithium-ion batteries, which is used to solve the problems in the prior art that the recycling process of lithium-ion batteries is complicated, and a large amount of waste water or organic solvents are generated, which is likely to cause environmental pollution.

Embodiments of the present invention provide a method for recycling waste lithium-ion batteries, including:

Obtaining completely discharged waste lithium-ion batteries, and crushing the lithium-ion batteries into fragments with a diameter of 10-100 mm;

The fragments are transported to the cyclone separator by the fan, and the fragments falling into the ash collecting hopper at the bottom of the cyclone separator are determined as the first fragments; the wind speed of the fan is between 10-14m/s , the pressure ranges from 0.1 to 0.15MPa;

crushing the first fragments into particles with a particle size of 10-200 μm, the particles are composed of a plurality of materials with different densities, and the particles are transported to the cyclone separator according to the wind speed set by the fan Among the particles, the particles with the first density fall into the dust collecting hopper through the cyclone separator, and the particles with the second density among the particles are discharged through the top outlet of the cyclone separator; The first density is greater than the second density.

Preferably, the wind speed of the fan is set according to the following formula:

Wherein, d _e is the critical particle diameter of the particle, μ is the gas viscosity, B is the air inlet width of the fan, _Ne is the effective number of rotations of the particle in the cyclone separator, and ρ _s is the The density of the particles, u _i is the inlet gas velocity of the fan.

Preferably, the waste lithium-ion battery includes a diaphragm, a gasket, a positive pole piece, a negative pole piece, a battery casing, a copper current collector and an aluminum current collector;

The positive electrode material is one of lithium cobalt oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, and lithium iron phosphate;

The negative electrode material is one of natural graphite, artificial graphite, lithium titanate, silicon carbon material;

The battery shell is one of steel shell, aluminum shell, and aluminum-plastic film.

Preferably, the said fragments are transported into the cyclone separator by the blower, and the fragments falling into the ash collecting hopper at the bottom of the cyclone separator are determined as the first fragments, specifically comprising:

When the wind speed of the fan is 10m/s and the pressure is 0.11MPa, the fragments move at a constant speed in the cyclone separator along with the airflow from top to bottom in a spiral line. Fragments and battery casing fragments fall into the ash collecting hopper, and the diaphragm and gasket move with the airflow from bottom to top in a spiral line at a constant speed, and are discharged from the outlet at the top of the cyclone separator.

Preferably, the particles are transported to the cyclone separator according to the wind speed set by the fan, and the particles with the first density among the particles fall to the dust collecting hopper through the cyclone separator In, the particles having the second density among the particles are discharged through the top discharge port of the cyclone separator, specifically comprising:

When the wind speed of the fan is 16m/s and the pressure is 0.11MPa, the particles in the cyclone separator move with the airflow from top to bottom in a spiral line at a constant speed, and the copper powder particles are separated by the cyclone. The container falls into the dust collecting hopper, and the aluminum powder particles, graphite powder particles, and iron powder particles are discharged through the top outlet of the cyclone separator; and

When the wind speed of the fan is 17m/s and the pressure is 0.11MPa, the particles move at a constant speed in the cyclone separator along with the airflow from top to bottom in a spiral line, and the iron powder particles are separated by the cyclone. The container falls into the dust collecting hopper, and the aluminum powder particles and the graphite powder particles are discharged through the top outlet of the cyclone separator; and

When the wind speed of the fan is 18m/s and the pressure is 0.11MPa, the particles in the cyclone separator move with the airflow from top to bottom in a spiral line at a constant speed, and the aluminum powder particles pass through the cyclone. The separator falls into the dust collecting hopper, and the graphite powder particles are discharged through the top outlet of the cyclone separator.

An embodiment of the present invention provides a method for recycling waste lithium-ion batteries, comprising: obtaining waste lithium-ion batteries that have been completely discharged, and crushing the lithium-ion batteries into fragments with a diameter of 10-100 mm; Transported to the cyclone separator by a blower fan, the fragments falling into the ash hopper at the bottom of the cyclone separator are determined as the first fragments; the wind speed of the blower fan is between 10-14m/s, and the pressure is between 0.1-0.15MPa; crush the first fragments into particles with a particle size of 10-200μm, the particles are composed of multiple materials with different densities, and the particles are transported to the In the cyclone separator, the particles with the first density among the particles fall into the dust collecting hopper through the cyclone separator, and the particles with the second density among the particles pass through the top of the cyclone separator A discharge port discharges; the first density is greater than the second density. In this recycling method, various materials included in waste lithium-ion batteries are transported to the cyclone separator according to different densities at different wind speeds, so that various materials of different densities can be separated accordingly. This method is simple to operate, and the The recovered battery materials are of high purity and are easy to recycle and reuse.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic flow chart of a recycling method for a waste lithium-ion battery provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a cyclone separator provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Fig. 1 exemplarily shows a schematic flow chart of a recycling method for a waste lithium-ion battery provided by an embodiment of the present invention. As shown in Fig. 1 , the method mainly includes the following steps:

Step 101, obtaining a completely discharged waste lithium-ion battery, and crushing the lithium-ion battery into fragments with a diameter of 10-100 mm;

Step 102, the fragments are transported to the cyclone separator by the fan, and the fragments falling into the ash collecting hopper at the bottom of the cyclone separator are determined as the first fragments; the wind speed of the fan is between 10- 14m/s, the pressure ranges from 0.1 to 0.15MPa;

Step 103, pulverize the first fragments into particles with a particle size of 10-200 μm, the particles are composed of a plurality of materials with different densities, and transport the particles to the In the cyclone separator, the particles with the first density among the particles fall into the dust collecting hopper through the cyclone separator, and the particles with the second density among the particles pass through the top outlet of the cyclone separator Expelling; the first density is greater than the second density.

In step 101, the waste lithium ion battery is completely discharged, and then the discharged waste lithium ion is mechanically crushed to obtain fragments with a diameter of 10-100 mm.

In practical application, since waste lithium-ion batteries include diaphragms, gaskets, positive pole pieces, negative pole pieces, battery casings, copper current collectors and aluminum current collectors, the crushed fragments include diaphragm fragments, gasket fragments, Positive electrode fragments, negative electrode fragments, battery case fragments, copper current collector fragments and aluminum current collector fragments.

Further, since the above-mentioned waste lithium-ion battery includes various materials, and moreover, the various materials have different densities, therefore, in the embodiment of the present invention, various materials can be distinguished according to the densities of the materials.

In the embodiment of the present invention, the positive electrode material contained in the waste lithium ion battery is one of lithium cobaltate, lithium manganate, lithium nickel manganese oxide, lithium nickel cobalt manganate, and lithium iron phosphate; the waste lithium ion battery contains The negative electrode material is one of natural graphite, artificial graphite, lithium titanate, and silicon-carbon material; the battery shell of the waste lithium ion battery is one of steel shell, aluminum shell, and aluminum-plastic film. Due to the large difference in the density of metal lithium oxide, metal copper, metal aluminum, and organic polymers, the cyclone separator provided by the embodiment of the present invention is a device that uses the action of inertial centrifugal force to separate dust particles from the airflow. equipment. When the critical particle size is the smallest particle diameter that can be completely separated in the cyclone separator, since the critical particle size is related to gas viscosity, inlet width, effective number of rotations, particle density, and inlet gas velocity, while gas viscosity, inlet The width of the gas port, the number of effective rotations, and the particle density are all definite values, so the various components of the battery can be separated in sequence according to different densities in the cyclone separator by changing the gas flow rate.

In step 102, the above-mentioned debris is transported to a cyclone separator by a fan, and FIG. 2 is a schematic structural diagram of a cyclone separator provided by an embodiment of the present invention. As shown in FIG. 2 , the cyclone separator mainly includes an inlet pipe 1 , an upper top cover 2 , an outlet pipe 3 , a cone 4 , a cylinder 5 and an ash collecting hopper 6 .

According to the diameter of the crushed fragments and formula (1), the wind speed of the fan can be determined when the fragments are transported to the cyclone separator for the first time. The lower spiral circuit moves at a constant speed, and the lithium-ion battery includes positive electrode fragments, negative electrode fragments, battery case fragments, copper current collectors and aluminum current collectors fall into the ash collecting hopper at the bottom of the cyclone separator, while The diaphragm, gasket, etc. included in the lithium-ion battery move with the airflow from bottom to top in a spiral line at a constant speed, and are discharged from the top outlet of the cyclone separator.

Wherein, d _e is the critical particle diameter of the particle, μ is the gas viscosity, B is the air inlet width of the fan, _Ne is the effective number of rotations of the particle in the cyclone separator, and ρ _s is the The density of the particles, u _i is the inlet gas velocity of the fan.

In order to distinguish and explain, the fragments falling into the ash collecting hopper are confirmed as the first fragments, and the density of the first fragments is higher than that of the fragments discharged from the top discharge port of the cyclone separator. In the embodiment of the present invention, the specific density of the first fragments is not limited.

Through the above method, the denser materials included in the lithium-ion battery can be recovered into the ash collection hopper, and correspondingly, the relatively lower-density materials included in the lithium-ion battery are discharged through the top of the cyclone separator. That is, through the cyclone separator for the first time, the various materials included in the lithium-ion battery can be preliminarily divided into two categories.

For example, according to the formula (1), when the wind speed of the fan is determined to be 10m/s and the pressure is 0.11MPa, the fragments move at a constant speed in a spiral line with the airflow from top to bottom in the cyclone separator, and the positive electrode fragments, Negative electrode fragments, battery shell fragments, copper current collectors and aluminum current collectors fall into the ash collection hopper, while the diaphragm and gasket move with the airflow from bottom to top in a spiral line at a constant speed, and are discharged at the top of the cyclone separator. discharge.

In step 103, the obtained first fragments are crushed into particles with a particle diameter of 10-200 μm, and the particles also include a plurality of materials with different densities, such as aluminum powder particles, graphite powder particles, and iron powder particles and copper powder particles.

According to the formula (1), the wind speed of the fan is set for the first time, and then the above-mentioned particles are transported into the cyclone separator, and the particles with the first density in the above-mentioned particles fall into the described ash collecting hopper through the cyclone separator, and the above-mentioned particles Particles with a second density are discharged through the top discharge of the cyclone separator. It should be noted that the first density here refers to materials with the same density, and the second density refers to multiple materials or one material smaller than the first density. For example, when two materials are included in the particle, the second density only includes one material, and the density of this material is less than that of the material with the first density; if three materials are included in the particle, the second density Two densities include two materials, both of which have a lower density than the material having the first density. In the embodiment of the present invention, there is no limitation on the quantity of the material included in the particles, and accordingly, no specific limitation is placed on the data of the material corresponding to the second density.

For example, when the particles include aluminum powder particles, graphite powder particles, iron powder particles and copper powder particles, the above-mentioned various particles need to be separated by a cyclone separator, and the following steps can be followed:

According to formula (1), when the wind speed of the fan is set to 16m/s and the pressure is 0.11MPa for the first time, the particles move in a spiral line with the airflow from top to bottom in the cyclone separator at a constant speed, and the copper powder particles pass through The cyclone separator falls into the ash collecting hopper, and the aluminum powder particles, graphite powder particles and iron powder particles are discharged through the top outlet of the cyclone separator.

According to the formula (1), when the wind speed of the fan is set to 17m/s for the second time, and the pressure is 0.11MPa, the particles in the cyclone separator move at a constant speed in a spiral line with the airflow from top to bottom, and the iron powder particles pass through The cyclone separator falls into the ash collecting hopper, and the aluminum powder particles and graphite powder particles are discharged through the top outlet of the cyclone separator.

According to the formula (1), when the wind speed of the fan is set to 18m/s for the second time, and the pressure is 0.11MPa, the particles in the cyclone separator move with the airflow from top to bottom in a spiral line at a constant speed, and the aluminum powder particles, Fall into the ash hopper through the cyclone separator, and the graphite powder particles are discharged through the top outlet of the cyclone separator.

The method for recycling a waste lithium-ion battery provided by the embodiment of the present invention will be further described below in combination with Embodiment 1 to Embodiment 3.

Embodiment one

Step 201, take 100 used LIR18650 steel shell cylindrical lithium-ion batteries whose positive electrode active material is lithium cobaltate, and discharge them at a constant current of 10mA, with a cut-off voltage of 0V. The fully discharged lithium-ion battery is directly mechanically disassembled into pieces with an equivalent diameter of 15-25mm;

Step 202, the equivalent diameter that obtains in step 201 is 15-25mm fragment is blown into cyclone separator by blower fan, and inlet wind speed is 12m/s, and pressure is 0.11MPa), and density such as polyethylene diaphragm, polypropylene spacer is less The fragments are discharged and collected at the discharge port at the top of the cyclone separator, and the denser fragments such as lithium cobalt oxide positive electrode sheet, graphite negative electrode sheet, aluminum current collector, copper current collector, and nickel-plated steel shell are collected in the ash collection bucket at the bottom of the cyclone separator;

In step 203, the lithium cobalt oxide positive electrode sheet, graphite negative electrode sheet, nickel-plated steel shell and other dense fragments obtained in step 202 are ball milled into particles with a particle size of 50-100 μm in a ball mill, and the obtained particles are passed through a fan The huge airflow is blown into the cyclone separator (the inlet wind speed is 16-19m/s, the pressure is 0.11MPa), and by changing the flow rate of the purge airflow, the particles such as lithium cobaltate, graphite, aluminum powder, copper powder, and iron powder are sequentially Separation, sorting and recycling;

The content of metal impurities in the recovered material was detected by inductively coupled plasma emission spectrometry, and the test results are shown in Table 1.

Impurity content in the recovered battery material in Table 1 Example 1

Aluminum/wt% Copper/wt% Cobalt/wt% Iron/wt% Lithium cobaltate 0.12 0.11 — 0.15 graphite 0.11 0.02 0.03 0.02 Aluminum powder — 0.04 0.11 0.16 copper powder 0.01 — 0.23 0.19 iron powder 0.01 0.17 0.21 —

Embodiment two

Step 301 , take 100 103450 square lithium-ion batteries whose positive active material is lithium manganate, and discharge them at a constant current of 10mA, with a cut-off voltage of 0V. The fully discharged lithium-ion battery is directly mechanically disassembled into pieces with an equivalent diameter of 20-30mm;

Step 302, the equivalent diameter obtained in step 301 is blown into the cyclone separator by blower blower into the fragments of 20-30mm equivalent diameter, the inlet wind speed is 13m/s, and the pressure is 0.11MPa), polypropylene diaphragm, nylon spacer etc. density is less The fragments are discharged and collected at the discharge port on the top of the cyclone separator, and the dense fragments such as lithium manganate positive electrode sheet, graphite negative electrode sheet, aluminum current collector, copper current collector, and aluminum metal shell are collected in the ash collection bucket at the bottom of the cyclone separator;

In step 303, the denser fragments such as the lithium manganate positive electrode sheet, the graphite negative electrode sheet, and the aluminum metal casing obtained in step 302 are ball milled into particles with a particle size of 75-150 μm in a ball mill, and the obtained particles are passed through the fan. The huge airflow is blown into the cyclone separator (the inlet wind speed is 14-17m/s, the pressure is 0.12MPa), by changing the flow rate of the sweeping airflow, the particles such as lithium manganate, graphite, aluminum powder, copper powder, etc. Sorted recycling;

The content of metal impurities in the recovered material was detected by inductively coupled plasma emission spectrometry, and the test results are shown in Table 2.

Impurity content in the recovered battery material in Table 2 Example 2

Aluminum/wt% Copper/wt% Manganese/wt% Lithium manganese oxide 0.19 0.05 — graphite 0.14 0.01 0.01 Aluminum powder — 0.02 0.05 copper powder 0.01 — 0.11

Embodiment Three

Step 401, take 100 waste GSP09185190 aluminum-plastic film soft-packed lithium-ion batteries whose positive electrode active material is lithium iron phosphate, and discharge them at a constant current of 100mA, with a cut-off voltage of 0V. The fully discharged lithium-ion battery is directly mechanically disassembled into fragments with an equivalent diameter of 25-50mm;

In step 402, the fragments obtained in step 401 with an equivalent diameter of 25-50mm are blown into the cyclone separator by a fan, the inlet wind speed is 11m/s, and the pressure is 0.11MPa), polyethylene diaphragm, nylon gasket, aluminum-plastic film, etc. The fragments with lower density are discharged and collected at the discharge port at the top of the cyclone separator, and the fragments with higher density, such as lithium iron phosphate positive electrode sheet, graphite negative electrode sheet, aluminum current collector, and copper current collector, are collected in the ash collection bucket at the bottom of the cyclone separator;

In step 403, the lithium iron phosphate positive electrode sheet, graphite negative electrode sheet, aluminum current collector, copper current collector and other dense fragments obtained in step 402 are ball milled into particles with a particle size of 75-125 μm in a ball mill, and the obtained The particles are blown into the cyclone separator through the huge airflow of the fan (the inlet wind speed is 13-16m/s, and the pressure is 0.13MPa). By changing the flow rate of the purge air, the particles such as lithium iron phosphate, graphite, aluminum powder, and copper powder are Separation, sorting and recycling;

The content of metal impurities in the recovered material was detected by inductively coupled plasma emission spectrometry, and the test results are shown in Table 3.

Impurity content in the recovered battery material in Table 3 Example 3

Aluminum/wt% Copper/wt% Phosphorus/wt% Iron/wt% Lithium iron phosphate 0.24 0.15 — — graphite 0.15 0.12 0.06 0.12 Aluminum powder — 0.16 0.02 0.05 copper powder 0.01 — 0.01 0.02

To sum up, the embodiment of the present invention provides a method for recycling waste lithium-ion batteries, comprising: obtaining waste lithium-ion batteries that have been completely discharged, and crushing the lithium-ion batteries into fragments with a diameter of 10-100 mm ; The fragments are transported to the cyclone separator by the blower fan, and the fragments falling into the ash collecting hopper at the bottom of the cyclone separator are determined as the first fragments; the wind speed of the blower fan is between 10-14m/ s, the pressure is between 0.1 and 0.15MPa; the first fragment is crushed into particles with a particle size between 10-200 μm, and the particles are composed of a plurality of materials with different densities. According to the wind speed set by the fan, the The particles are transported into the cyclone separator, the particles with the first density among the particles fall into the dust collecting hopper through the cyclone separator, and the particles with the second density among the particles pass through the The top discharge of the cyclone is discharged; the first density is greater than the second density. In this recycling method, various materials included in waste lithium-ion batteries are transported to the cyclone separator according to different densities at different wind speeds, so that various materials of different densities can be separated accordingly. This method is simple to operate, and the The recovered battery materials are of high purity and are easy to recycle and reuse.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (5)

1. A recovery method for waste lithium-ion batteries, characterized in that, comprising: Obtaining completely discharged waste lithium-ion batteries, and crushing the lithium-ion batteries into fragments with a diameter of 10-100 mm; The fragments are transported into the cyclone separator by the fan, and the fragments falling into the ash collecting hopper at the bottom of the cyclone separator are determined as the first fragments; the wind speed of the fan is between 10-14m/s , the pressure ranges from 0.1 to 0.15MPa; crushing the first fragments into particles with a particle size of 10-200 μm, the particles are composed of a plurality of materials with different densities, and the particles are transported to the cyclone separator according to the wind speed set by the fan Among the particles, the particles with the first density fall into the dust collecting hopper through the cyclone separator, and the particles with the second density among the particles are discharged through the top outlet of the cyclone separator; The first density is greater than the second density. 2. The method according to claim 1, wherein the fan speed is set according to the following formula: Wherein, d _e is the critical particle diameter of the particle, μ is the gas viscosity, B is the air inlet width of the fan, _Ne is the effective number of rotations of the particle in the cyclone separator, and ρ _s is the The density of the particles, u _i is the inlet gas velocity of the fan. 3. The method according to claim 1, wherein the waste lithium ion battery comprises a separator, a gasket, a positive pole piece, a negative pole piece, a battery case, a copper current collector and an aluminum current collector; The positive electrode material is one of lithium cobalt oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, and lithium iron phosphate; The negative electrode material is one of natural graphite, artificial graphite, lithium titanate, silicon carbon material; The battery shell is one of steel shell, aluminum shell, and aluminum-plastic film. 4. The method according to claim 3, wherein the fragments are transported into a cyclone separator by a blower fan, and the fragments falling into the ash collecting hopper at the bottom of the cyclone separator are determined It is the first fragment, specifically including: When the wind speed of the fan is 10m/s and the pressure is 0.11MPa, the fragments move at a constant speed in the cyclone separator along with the airflow from top to bottom in a spiral line. Fragments, battery shell fragments, copper current collectors and aluminum current collectors fall into the ash collecting hopper, diaphragms and gaskets move at a constant speed in a spiral line with the airflow from bottom to top, and discharge at the top of the cyclone separator discharge. 5. The method according to claim 4, wherein the particles are transported to the cyclone separator according to the wind speed set by the blower, and the particles with the first density in the particles pass through The cyclone separator falls into the dust collecting hopper, and the particles having the second density among the particles are discharged through the top outlet of the cyclone separator, specifically including: When the wind speed of the fan is 16m/s and the pressure is 0.11MPa, the particles in the cyclone separator move with the airflow from top to bottom in a spiral line at a constant speed, and the copper powder particles are separated by the cyclone. The container falls into the dust collecting hopper, and the aluminum powder particles, graphite powder particles, and iron powder particles are discharged through the top outlet of the cyclone separator; and When the wind speed of the fan is 17m/s and the pressure is 0.11MPa, the particles move at a constant speed in the cyclone separator along with the airflow from top to bottom in a spiral line, and the iron powder particles are separated by the cyclone. The container falls into the dust collecting hopper, and the aluminum powder particles and the graphite powder particles are discharged through the top outlet of the cyclone separator; and When the wind speed of the fan is 18m/s and the pressure is 0.11MPa, the particles in the cyclone separator move with the airflow from top to bottom in a spiral line at a constant speed, and the aluminum powder particles pass through the cyclone. The separator falls into the dust collecting hopper, and the graphite powder particles are discharged through the top outlet of the cyclone separator.