Carbon material microwave synergistic magnetic separation deashing method and device and carbon material

Abstract

The invention relates to the technical field of porous carbon preparation, in particular to a microwave-assisted magnetic separation deashing method and device for a carbon material and the carbon material.The carbon material is sequentially subjected to grinding, microwave irradiation, magnetic field application and iron-containing ash removal, the carbon material subjected to deep deashing is obtained, and deashing of the carbon material is completed; physical combination of the iron-containing ash and a carbon material matrix can be destroyed through grinding, so that the iron-containing ash is fully exposed, and the situation that the carbon material generates a wrapping effect on the iron-containing ash, and consequently the magnetic separation effect is affected is avoided; the hot spot effect of microwave irradiation can preferentially heat an iron compound to promote the iron compound to be converted into a strong magnetic phase, so that the magnetic response of the iron-containing ash is improved, deep removal of the iron-containing ash of the carbon material can be achieved by cooperating with magnetic field application, the iron content of the dedusted carbon material is smaller than 100 mg / kg, and the problems that in the prior art, a carbon material magnetic separation method is poor in deashing effect and low in deashing efficiency are solved. And the actual deliming requirement cannot be met.

Description

Technical Field

[0001] The invention relates to the technical field of porous carbon preparation, and in particular to a microwave-assisted magnetic separation deashing method and device for carbon materials, and carbon materials. Background Art

[0002] Carbon materials are abundant and easy to obtain, and can be combined with different atoms through hybridization, thus having many advantages such as electrical conductivity, thermal conductivity, and stable chemical properties. Carbon materials have a unique sp² / sp³ hybrid structure, and the electron mobility is as high as 2*10 5 cm² / (V·s), which is better than most metal alloys. It is often used as electrode materials, thermal conductive fillers, catalytic carriers, nuclear reactor shielding materials, etc., and plays an important role in the fields of adsorption, catalysis and energy storage. However, the performance of carbon materials is highly dependent on the purity of carbon materials. Taking supercapacitors as an example, the Fe content in ash is 3+ It will trigger redox reactions during electrolysis, accelerate electrode aging, and reduce the service life of supercapacitors. In addition, it will cover active sites, reduce the effective specific surface area, and easily lead to problems such as capacitance attenuation. Some fields have strict requirements on the ash and iron content of carbon materials. For example, the standard for activated carbon for supercapacitors requires that the ash content in the carbon material should not exceed 0.2% and the iron content should not exceed 100 mg / kg. At present, the iron content of most carbon material precursors is relatively high. At the same time, during the large-scale production process, carbon materials must constantly contact steel materials, such as carbonization furnaces, cremation furnaces, etc., resulting in serious excess of ash and iron content in carbon materials. Therefore, carbon materials need to be deashed before use.

[0003] At present, there are three main deashing methods, namely physical deashing, chemical deashing and physical-chemical deashing; among them, chemical deashing is to use chemical reagents to react with ash components to generate soluble or easily separable substances, including acid washing, alkali washing and oxidation methods. The reagents and equipment are corrosive and consume a lot, and it is easy to destroy the pore structure of carbon materials; chemical deashing and physical-chemical deashing are to combine physical means with chemical reagents to enhance the deashing effect. The process is complicated and is in the experimental stage and cannot be applied to production on a large scale. Physical deashing is to separate ash and carbon materials through physical effects such as gravity, centrifugal force, magnetism, screening, etc., including magnetic separation, flotation and screening. Relatively speaking, it will not change the basic chemical properties of carbon materials, is simple to operate and has low cost, and is widely used in actual carbon material production processes.

[0004] In the actual process of carbon material production, magnetic separation for ash removal is a key step to remove iron-containing ash. To remove iron-containing ash as much as possible at each stage, a demagnetization unit needs to be equipped at each stage, especially after coal powder grinding, carbonization, and activation. The iron-containing ash is screened out through the demagnetization unit to achieve ash removal of carbon materials. However, in the actual production process, the morphology of iron-containing ash usually changes due to the treatment in the high-temperature carbonization and activation stages. For example, in the high-temperature carbonization stage, some Fe3O4 is reduced to FeO (weak magnetism) or Fe (non-magnetism) due to high temperature, and treatments such as pickling and steam activation in the activation stage may dissolve some iron impurities, but the residual iron may still exist in the form of non-magnetic oxides (such as α-Fe2O3). These morphological changes will lead to a decrease or even disappearance of the magnetism of iron-containing ash, thus reducing the demagnetization effect in the whole process and failing to meet the production requirements and usage requirements of actual carbon materials. Summary of the Invention

[0005] Aiming at the problem that the ash removal effect of the magnetic separation method for carbon materials in the prior art is poor and cannot meet the actual ash removal requirements, the present invention provides a microwave-assisted magnetic separation ash removal method, device and carbon material for carbon materials.

[0006] To achieve the above object, the present invention adopts the following technical solutions: The present invention provides a microwave-assisted magnetic separation ash removal method for carbon materials, including: Fully grinding the carbon materials to fully dissociate the iron-containing ash from the carbon materials, obtaining pre-ash-removed carbon materials; Performing microwave irradiation on the pre-ash-removed carbon materials to obtain high-magnetic pre-ash-removed carbon materials; Applying a magnetic field to the high-magnetic pre-ash-removed carbon materials to remove the iron-containing ash, obtaining deeply ash-removed carbon materials, and completing the ash removal of the carbon materials.

[0007] Optionally, the particle size of the pre-ash-removed carbon materials is less than 200 mesh.

[0008] Optionally, the power of the microwave irradiation is 500 - 1000 W.

[0009] Optionally, the time of the microwave irradiation is 10 - 200 s.

[0010] Optionally, the wet high-intensity magnetic separation method is used to apply a magnetic field to the high-magnetic pre-ash-removed carbon materials to remove the iron-containing ash, obtaining deeply ash-removed carbon materials.

[0011] Optionally, the liquid medium of the wet high-intensity magnetic separation method is water and / or ethanol, and the solid-liquid ratio of the high-magnetic pre-ash-removed carbon materials to the liquid medium is (1:5) - (1:10).

[0012] Optionally, the magnetic field strength of the wet high-intensity magnetic separation method is 0.5-2T, and the flow rate of the liquid medium is 0.1-0.5m / s.

[0013] The present invention provides a carbon material, and the above microwave-assisted magnetic separation and deashing method is used for deashing.

[0014] The present invention also provides a microwave-assisted magnetic separation and deashing device for carbon materials, which includes a grinding unit, a microwave irradiation unit and a demagnetization unit connected to the grinding unit in sequence; The grinding unit is used to fully grind the carbon material to fully dissociate the iron-containing ash from the carbon material, and obtain a pre-deashed carbon material; The microwave irradiation unit is used to irradiate the pre-deashed carbon material with microwaves to obtain a highly magnetic pre-deashed carbon material; The demagnetization unit is used to apply a magnetic field to the highly magnetic pre-deashed carbon material to remove the iron-containing ash and obtain a deeply deashed carbon material.

[0015] Optionally, the microwave-assisted magnetic separation and deashing device for carbon materials further includes a control unit, which is electrically connected to the grinding unit, the microwave irradiation unit and the demagnetization unit, and is used for intelligently controlling the grinding unit, the microwave irradiation unit and the demagnetization unit.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a microwave-assisted magnetic separation and deashing method for carbon materials. This method removes iron-containing ash by sequentially grinding, microwave irradiating and applying a magnetic field to the carbon material to obtain a deeply deashed carbon material, completing the deashing of the carbon material; among them, grinding can destroy the physical combination between the iron-containing ash and the carbon material matrix, fully expose the iron-containing ash, and avoid the "encapsulation effect" of the carbon material on the iron-containing ash, which affects the magnetic separation effect; the "hot spot effect" of microwave irradiation will preferentially heat iron compounds, promoting their transformation into a strong magnetic phase, thereby enhancing the magnetic response of the iron-containing ash, and cooperating with the magnetic field application can achieve deep removal of the iron-containing ash in the carbon material. The iron content of the deashed carbon material is less than 100mg / kg, meeting the deashing requirements of carbon materials in current special scenarios. In particular, microwave irradiation can also enhance the paramagnetism of the demagnetized iron-containing substances, so that the demagnetization unit in the actual production process can be combined into one, which can greatly reduce the equipment investment and operation costs and improve the production efficiency of carbon materials. This method is simple, easy to operate and low in cost, and is more suitable for large-scale production of carbon materials.

[0017] The particle size of the pre-ash-removed carbon material is less than 200 mesh, and the particle size of the carbon material below 200 mesh is less than 75 μm, which can significantly destroy the physical bond between the carbon matrix and the iron-containing ash, fully expose the iron-containing ash originally wrapped or embedded inside the carbon material, with a dissociation degree of more than 90%, avoiding the escape of non-magnetic inclusions during magnetic separation; meanwhile, the refined ash-carbon material has a larger specific surface area, providing sites for subsequent microwave irradiation, making it easier for microwave energy to penetrate and selectively heat the iron-containing ash, and also being more easily captured by the subsequent magnetic separation process.

[0018] The power of the microwave irradiation is 500 - 1000 W, and the time of the microwave irradiation is 10 - 200 s. The dielectric loss of iron compounds is much higher than that of carbon materials, and they preferentially absorb energy in the 500 - 1000 W microwave field, causing the local temperature to rise rapidly, thereby using the microwave thermal effect to drive the lattice reconstruction of low-magnetic iron-containing ash to generate strongly magnetic iron-containing ash. However, with the increase of time, the specific magnetic susceptibility of the iron-containing ash will show a trend of first increasing and then decreasing. For example, in the stage of increasing specific magnetic susceptibility, as the system temperature rises, pyrite undergoes crystal form transformation to generate strongly magnetic minerals; while in the stage of decreasing specific magnetic susceptibility, with the extension of time, the generated pyrrhotite further decomposes into siderite (almost non-magnetic). Therefore, it is necessary to control the time of microwave irradiation to 10 - 200 s to lock the high-magnetic intermediate state of iron compounds and avoid the loss of magnetism caused by excessive microwave irradiation or insufficient microwave irradiation affecting the magnetic separation effect.

[0019] The wet high-intensity magnetic separation method is used to apply a magnetic field to the high-magnetic pre-ash-removed carbon material to remove the iron-containing ash, obtaining a carbon material with deep ash removal. The wet high-intensity magnetic separation is a beneficiation technology that uses a strong magnetic field to efficiently separate magnetic minerals in a liquid medium, widely used in the separation of weakly magnetic or fine-grained minerals. Its core principle is to achieve the precise separation of magnetic minerals and non-magnetic minerals through the synergistic effect of high-intensity magnetic field and hydrodynamics, with advantages such as high separation efficiency and strong adaptability. Selecting the wet high-intensity magnetic separation to apply a magnetic field to the high-magnetic pre-ash-removed carbon material to remove the iron-containing ash can use the liquid medium to disperse particles, avoid the dust loss in dry separation, and is safer and easier to operate. The liquid medium of the wet high-intensity magnetic separation method is water and / or ethanol, and the solid-liquid ratio of the high-magnetic pre-ash-removed carbon material to the liquid medium is (1:5) - (1:10). Using water and / or ethanol as the liquid medium can ensure the dispersion of the high-magnetic pre-ash-removed carbon material in the liquid medium while avoiding the introduction of other impurities that affect the matrix performance of the carbon material.

[0020] For the wet high-intensity magnetic separation method, the magnetic field strength is 0.5 - 2T, and the flow rate of the liquid medium is 0.1 - 0.5m / s. The magnetic field strength of 0.5 - 2T can efficiently capture iron particles from the micron level to the sub-micron level, further enhancing the removal effect of iron-containing ash and enabling it to meet the carbon standard for supercapacitors. The flow rate of the liquid medium being 0.1 - 0.5m / s can, while ensuring the ash removal efficiency, extend the residence time of the particles in the magnetic field region, prevent the escape of iron particles caused by too high a flow rate, and improve the ash removal efficiency and effect.

[0021] The present invention provides a carbon material which is deashed by using the above-mentioned microwave-assisted magnetic separation deashing method. Since this carbon material is deashed by using the above-mentioned microwave-assisted magnetic separation deashing method, the iron-containing ash content inside this carbon material is less than 100mg / kg, it has higher purity and better performance, and meets the ash removal requirements for carbon materials in special scenarios (such as supercapacitors, lithium-ion batteries, etc.).

[0022] The present invention also provides a microwave-assisted magnetic separation deashing device for carbon materials. This device highly integrates a grinding unit, a microwave irradiation unit and a demagnetization unit which are sequentially connected to the grinding unit, realizing continuous ash removal of carbon materials. Among them, the grinding unit is responsible for fully grinding the carbon materials, breaking the physical bond between the iron-containing ash and the carbon material matrix, making the iron-containing ash fully exposed, and avoiding the "encapsulation effect" of the carbon material on the iron-containing ash, thereby improving the subsequent magnetic separation effect. The microwave irradiation unit is responsible for microwave irradiating the ground carbon materials, heating the iron compounds by using the "hot spot effect" of microwave irradiation, and promoting their transformation into a ferromagnetic phase, thereby enhancing the magnetic response of the iron-containing ash. The demagnetization unit is responsible for applying a magnetic field to the high-magnetic pre-deashed carbon materials, capturing and removing the high-magnetic iron-containing ash, realizing deep ash removal. The device has a simple structure, low investment and operation costs, is easy to maintain and manage, and has broad application prospects in the field of carbon material production.

[0023] It also includes a control unit, which is electrically connected to the grinding unit, the microwave irradiation unit and the demagnetization unit, and is used for intelligently controlling the grinding unit, the microwave irradiation unit and the demagnetization unit. The setting of the control unit can be through integrated programming, and the parameters of the three units of grinding, microwave irradiation and demagnetization (such as grinding time, microwave power, magnetic field strength, etc.) can be adjusted and linked in real time, realizing full-process automated operation, reducing manual intervention, reducing operation errors, and ensuring process stability; at the same time, a fault diagnosis algorithm can be built in, and the operating state of the equipment (such as motor current, microwave leakage, magnetic field fluctuation, etc.) can be monitored in real time through threshold alarm (such as microwave irradiation temperature or time threshold), trend prediction (such as microwave source power attenuation) and correlation analysis (such as deviation between magnetic field strength and ash removal rate), etc., to early warn potential faults; in addition, the control unit can also record the full-process operation data and generate a traceable process report, providing a reliable basis for the process adjustment of subsequent production, and providing a standardized and intelligent solution for the industrial application of the carbon material ash removal process, especially applicable to fields such as supercapacitors and lithium-ion batteries that are sensitive to ash content. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 FIG. is a schematic flow chart of a microwave-assisted magnetic separation ash removal method for a carbon material of the present invention.

[0025] Figure 2 FIG. is a structural diagram of a microwave-assisted magnetic separation ash removal device for a carbon material of the present invention.

[0026] Among them, 1 - grinding unit, 2 - microwave irradiation unit, 3 - demagnetization unit, 4 - control unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] To enable those skilled in the art to understand the features and effects of the present invention, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art for the present invention. When there are conflicts, the definition in this specification shall prevail.

[0028] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0029] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents and concentrations, are only for the sake of simplicity and convenience. Accordingly, the description of the numerical range or percentage range should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0030] In this article, unless otherwise specified, the terms "include", "comprise", "contain", "have" or similar terms cover the meanings of "consist of" and "consist essentially of". For example, "A includes a" covers the meanings of "A includes a and others" and "A only includes a".

[0031] In this article, for the sake of concise description, not all possible combinations of all technical features in each embodiment or example are described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope described in this specification.

[0032] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0033] Conventional instruments and equipment in the art are used in the following examples. For the experimental methods without specific conditions indicated in the following examples, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. Various raw materials are used in the following examples. Unless otherwise stated, conventional commercially available products are used, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0034] The present invention will be further described in detail below in conjunction with specific embodiments, which are explanations rather than limitations of the present invention.

[0035] See Figure 1 , the present invention discloses a method for microwave-assisted magnetic separation of ash from carbon materials, including S1: Grind the carbon material sufficiently to fully dissociate the iron-containing ash from the carbon material, and obtain the pre-ashed carbon material. Specifically: Grind the carbon material sufficiently to below 200 mesh to fully dissociate the iron-containing ash from the carbon material, and obtain the pre-ashed carbon material.

[0036] S2: Perform microwave irradiation on the pre-ashed carbon material to obtain a highly magnetic pre-ashed carbon material. Specifically: Under a power of 500 - 1000 W, perform microwave irradiation on the pre-ashed carbon material for 10 - 200 s to enhance the magnetism of the iron-containing ash and obtain a highly magnetic pre-ashed carbon material.

[0037] S3: Apply a magnetic field to the high-magnetic pre-ash-removed carbon material to remove iron-containing ash, obtaining a carbon material with deep ash removal and completing the ash removal of the carbon material. Specifically: Using water and / or ethanol as the liquid medium, apply a magnetic field to the high-magnetic pre-ash-removed carbon material by wet high-intensity magnetic separation to remove iron-containing ash, obtaining a carbon material with deep ash removal. Preferably, the solid-liquid ratio of the high-magnetic pre-ash-removed carbon material to the liquid medium is (1:5) to (1:10). The magnetic field strength of the wet high-intensity magnetic separation method is 0.5 - 2T, and the flow rate of the liquid medium is 0.1 - 0.5m / s.

[0038] Preferably, after magnetic separation to screen out iron-containing ash, for further deep ash removal, H + A hydrochloric acid solution or oxalic acid solution with a concentration of 1 - 5mol / L can be used for pickling to further remove iron-containing ash and other ash, thereby achieving complete removal of ash.

[0039] The present invention provides a carbon material, which is deashed by the above microwave-assisted magnetic separation deashing method. Since this carbon material is deashed by the above microwave-assisted magnetic separation deashing method, the iron-containing ash in the carbon material is less than 100mg / kg, having higher purity and better performance, meeting the ash removal requirements of carbon materials for special scenarios (such as supercapacitors, lithium-ion batteries, etc.).

[0040] Example 1 Fully grind 1kg of carbon material to below 200 mesh to fully dissociate the iron-containing ash from the carbon material, obtaining a pre-ash-removed carbon material.

[0041] Irradiate the pre-ash-removed carbon material with microwaves at a power of 500W for 200s to enhance the magnetism of the iron-containing ash, obtaining a high-magnetic pre-ash-removed carbon material.

[0042] Using water as the liquid medium, apply a 0.5T magnetic field to the high-magnetic pre-ash-removed carbon material by wet high-intensity magnetic separation to remove iron-containing ash, obtaining a carbon material with deep ash removal; among them, the solid-liquid ratio of the high-magnetic pre-ash-removed carbon material to water is 1:5, and the water flow rate is 0.5m / s; for the ash content test result of this carbon material with deep ash removal, it is found that the content of iron-containing ash in this carbon material with deep ash removal drops from the original 4920mg / kg to 100mg / kg. After magnetic separation to screen out iron-containing ash, for further deep ash removal, H + A hydrochloric acid solution with a concentration of 1mol / L can be used for pickling to further remove iron-containing ash and other ash. After detection, the content of iron-containing ash in the carbon material after pickling drops to 50mg / kg.

[0043] Example 2 Fully grind 1kg of carbon material to below 200 mesh to fully dissociate the iron-containing ash from the carbon material, obtaining a pre-ash-removed carbon material.

[0044] Under a power of 600 W, the pre - de - ashed carbon material is irradiated with microwaves for 150 s to enhance the magnetism of the iron - containing ash, and a high - magnetism pre - de - ashed carbon material is obtained.

[0045] Using a liquid medium with a volume ratio of ethanol to water of 1:1, the high - magnetism pre - de - ashed carbon material is subjected to a magnetic field of 1 T by wet high - intensity magnetic separation to remove the iron - containing ash, and a deeply de - ashed carbon material is obtained; among them, the solid - liquid ratio of the high - magnetism pre - de - ashed carbon material to water is 1:6, and the water flow rate is 0.5 m / s; from the ash content test results of this deeply de - ashed carbon material, it is found that the content of iron - containing ash in this deeply de - ashed carbon material drops from the original 4920 mg / kg to 99.8 mg / kg. After magnetic separation to screen out the iron - containing ash, for further deep de - ashing, H + A hydrochloric acid solution with a concentration of 1 mol / L can be used for pickling to further remove the iron - containing ash and other ash. After detection, the content of iron - containing ash in the carbon material after pickling drops to 49.9 mg / kg.

[0046] Example 3 1 kg of carbon material is fully ground to below 200 meshes to fully dissociate the iron - containing ash from the carbon material, and a pre - de - ashed carbon material is obtained.

[0047] Under a power of 800 W, the pre - de - ashed carbon material is irradiated with microwaves for 80 s to enhance the magnetism of the iron - containing ash, and a high - magnetism pre - de - ashed carbon material is obtained.

[0048] Using ethanol as the liquid medium, the high - magnetism pre - de - ashed carbon material is subjected to a magnetic field of 2 T by wet high - intensity magnetic separation to remove the iron - containing ash, and a deeply de - ashed carbon material is obtained; among them, the solid - liquid ratio of the high - magnetism pre - de - ashed carbon material to water is 1:10, and the water flow rate is 0.4 m / s; from the ash content test results of this deeply de - ashed carbon material, it is found that the content of iron - containing ash in this deeply de - ashed carbon material drops from the original 4920 mg / kg to 98.7 mg / kg. After magnetic separation to screen out the iron - containing ash, for further deep de - ashing, H + An oxalic acid solution with a concentration of 1 mol / L can be used for pickling to further remove the iron - containing ash and other ash. After detection, the content of iron - containing ash in the carbon material after pickling drops to 49.8 mg / kg.

[0049] Example 4 1 kg of carbon material is fully ground to below 200 meshes to fully dissociate the iron - containing ash from the carbon material, and a pre - de - ashed carbon material is obtained.

[0050] Under a power of 1000 W, the pre - de - ashed carbon material is irradiated with microwaves for 10 s to enhance the magnetism of the iron - containing ash, and a high - magnetism pre - de - ashed carbon material is obtained.

[0051] Using water as the liquid medium, the wet high-intensity magnetic separation method is adopted to apply a 1.5T magnetic field to the high-magnetic pre-ash-removing carbon material to remove iron-containing ash and obtain a carbon material with deep ash removal; wherein, the solid-liquid ratio of the high-magnetic pre-ash-removing carbon material to water is 1:8, and the water flow rate is 0.3m / s; regarding the ash content test result of this carbon material with deep ash removal, it is found that the content of iron-containing ash in this carbon material with deep ash removal drops from the original 4920mg / kg to 100mg / kg. After magnetic separation to screen out iron-containing ash, for further deep ash removal, H + hydrochloric acid solution with a concentration of 3mol / L can be used for pickling to further remove iron-containing ash and other ash. After detection, the content of iron-containing ash in the carbon material after pickling drops to 49.6mg / kg.

[0052] See Figure 2 , the present invention also provides a microwave-assisted magnetic separation and ash removal device for carbon materials, including a grinding unit 1, a microwave irradiation unit 2, a demagnetization unit 3 and a control unit 4. The grinding unit 1 is sequentially connected to the microwave irradiation unit 2 and the demagnetization unit 3. The control unit 4 is electrically connected to the grinding unit 1, the microwave irradiation unit 2 and the demagnetization unit 3; the grinding unit 1 is responsible for fully grinding the carbon material, destroying the physical combination between the iron-containing ash and the carbon material matrix, making the iron-containing ash fully exposed, and avoiding the "encapsulation effect" of the carbon material on the iron-containing ash, thereby improving the subsequent magnetic separation effect; the microwave irradiation unit 2 is responsible for performing microwave irradiation on the ground carbon material, using the "hot spot effect" of microwave irradiation to heat the iron compound and promoting its transformation into a ferromagnetic phase, thereby enhancing the magnetic response of the iron-containing ash; the demagnetization unit 3 is responsible for applying a magnetic field to the high-magnetic pre-ash-removing carbon material, capturing and removing the high-magnetic iron-containing ash, realizing deep ash removal. The device has a simple structure, low investment and operation costs, is easy to maintain and manage, and has broad application prospects in the field of carbon material production; the control unit 4 is used for intelligent control of the grinding unit 1, the microwave irradiation unit 2 and the demagnetization unit 3. The setting of the control unit 4 can be through integrated programming, and the parameters of the grinding unit 1, the microwave irradiation unit 2 and the demagnetization unit 3 (such as grinding time, microwave power, magnetic field strength, etc.) can be adjusted and linked in real time to realize full-process automatic operation, reduce manual intervention, reduce operation errors, and ensure process stability; at the same time, a fault diagnosis algorithm can be built in, and the operation status of the equipment (such as motor current, microwave leakage, magnetic field fluctuation, etc.) can be monitored in real time through threshold alarm (such as microwave irradiation temperature or time threshold), trend prediction (such as microwave source power attenuation) and correlation analysis (such as deviation between magnetic field strength and ash removal rate) etc. to early warn potential faults; in addition, the whole-process operation data can be recorded through the control unit and a traceable process report can be generated, providing a reliable basis for the process adjustment of subsequent production, and providing a standardized and intelligent solution for the industrial application of the carbon material ash removal process, especially suitable for fields such as supercapacitors and lithium-ion batteries that are sensitive to ash content.

[0053] Preferably, the grinding unit 1 includes a jet mill and an ultrasonic vibrating screen. The jet mill is used to fully grind the carbon material to achieve ultra-fine grinding. The ultrasonic vibrating screen is used to screen the carbon material with a mesh size below 200 meshes to obtain pre-ashed carbon material, with high screening efficiency and accuracy. When the microwave irradiation unit 2 performs microwave irradiation, it includes an inert gas supply module for providing an inert gas for microwave irradiation, suppressing the oxidation and burning loss of the carbon material at high temperatures while ensuring the stability of the magnetic enhancement effect.

[0054] The above are only the preferred embodiments of the present invention, and are not used to limit the technical solutions of the present invention. Those skilled in the art should understand that without departing from the spirit and principles of the present invention, the technical solutions can be subject to several simple modifications and substitutions, and these modifications and substitutions also fall within the protection scope covered by the claims.

Claims

1. A method for microwave-assisted magnetic separation and ash removal of carbon materials, characterized in that, Including: Fully grinding the carbon material to fully dissociate the iron-containing ash from the carbon material, obtaining a pre-ashed carbon material; Performing microwave irradiation on the pre-ashed carbon material to obtain a highly magnetic pre-ashed carbon material; Applying a magnetic field to the highly magnetic pre-ashed carbon material to remove the iron-containing ash, obtaining a carbon material with deep ash removal, and completing the ash removal of the carbon material.

2. The microwave-assisted magnetic separation method for ash removal of the carbon material according to claim 1, characterized in that, The particle size of the pre-ashed carbon material is less than 200 mesh.

3. The microwave-assisted magnetic separation method for ash removal of the carbon material according to claim 1, characterized in that The power of the microwave irradiation is 500 - 1000 W.

4. The microwave-assisted magnetic separation method for ash removal of the carbon material according to claim 1, characterized in that, The time of microwave irradiation is 10 - 200 s.

5. The microwave-assisted magnetic separation method for ash removal of the carbon material according to claim 1, characterized in that Using the wet high-intensity magnetic separation method to apply a magnetic field to the highly magnetic pre-ashed carbon material to remove the iron-containing ash, obtaining a carbon material with deep ash removal.

6. The microwave-assisted magnetic separation method for ash removal of the carbon material according to claim 5, wherein, The liquid medium of the wet high-intensity magnetic separation method is water and / or ethanol, and the solid-liquid ratio of the highly magnetic pre-ashed carbon material to the liquid medium is (1:5) - (1:10).

7. The microwave-assisted magnetic separation method for ash removal of carbon materials according to claim 5, characterized in that The magnetic field intensity of the wet high-intensity magnetic separation method is 0.5 - 2 T, and the flow rate of the liquid medium is 0.1 - 0.5 m / s.

8. A carbon material, characterized in that, Performing ash removal using the microwave-assisted magnetic separation ash removal method described in any one of claims 1 - 7.

9. A microwave-assisted magnetic separation device for ash removal of carbon materials, characterized in that, Including a grinding unit and a microwave irradiation unit and a demagnetization unit connected to the grinding unit in sequence; The grinding unit is used to fully grind the carbon material to fully dissociate the iron-containing ash from the carbon material, obtaining a pre-ashed carbon material; The microwave irradiation unit is used to perform microwave irradiation on the pre-ashed carbon material to obtain a highly magnetic pre-ashed carbon material; The demagnetization unit is used to apply a magnetic field to the highly magnetic pre-ashed carbon material to remove the iron-containing ash, obtaining a carbon material with deep ash removal.

10. The microwave-assisted magnetic separation and ash removal device for carbon materials according to claim 9, characterized in that, It further includes a control unit, which is electrically connected to the grinding unit, the microwave irradiation unit, and the demagnetization unit, and is used to perform intelligent control on the grinding unit, the microwave irradiation unit, and the demagnetization unit.

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