Carbon material based on gradient deliming of coal, coke and activated carbon and deep deliming method of carbon material
Through the coal, coke and activated carbon cascade deamination method, combined with the step-by-step treatment of weak acid, strong acid and strong alkali solutions, the existing coal deamination methods are solved, and the efficient and low-cost deep deamination is achieved, high-purity carbon materials are obtained, and the stability and electrochemical performance of the material are improved.
Patent Information
- Application Number
- CN202510548200.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-28
- Publication Date
- 2025-07-08
AI Technical Summary
The existing coal deamination method has complex processes and high costs, making it difficult to achieve deep deamination. It often requires multiple methods to use superimposed or large amounts of reagents, resulting in a significant increase in costs and the lack of full use of their respective deamination potential.
The coal, coke and activated carbon are used to remove the ash from coal powder by soaking in low-temperature weak acid solution, soaking in low-temperature strong acid solution to remove the hard-dissolved ash from heat-removing coke, and the low-temperature strong alkali solution to remove the residual ash from activated carbon, so as to achieve step-by-step and deep removal of the ash.
It significantly improves the ash removal efficiency, reduces the processing time and cost, reduces the difficulty of waste liquid treatment and environmental pollution, obtains high-purity carbon materials, and ensures the stability of the material under high temperature conditions and excellent performance in the electrochemical environment.
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Figure CN120270994A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of coal deashing, and relates to a carbon material based on cascade deashing of coal, coke and activated carbon and a deep deashing method thereof. Background Art
[0002] Carbon materials are widely used in electrochemistry, pollutant adsorption and catalysis due to their stable structure, adjustable mesophase pore structure and physical and chemical properties. Coal is the cheapest and most abundant natural carbon source in nature. Its basic structural unit is "aromatic center with aliphatic side chains connected by bridge bonds", which is close to the carbon material structure with "aromatic ring as the core". It is uniquely suited for the development of coal-based carbon electrode materials. Compared with biomass precursors, coal contains a large amount of ash inside due to its unique formation process. Carbon materials prepared with coal as a precursor inevitably contain a large amount of ash. The presence of ash will have a negative impact on the subsequent application of carbon materials, such as affecting stable operation and causing performance degradation. Therefore, relevant national and industry standards have put forward strict requirements on the ash content in carbon materials. For example, the national standard for activated carbon for supercapacitors (GBT37386-2019) requires that the ash content in carbon materials is not higher than 0.2%.
[0003] At present, there are three main mainstream deashing methods, namely physical deashing, chemical deashing and physical-chemical deashing. Physical deashing methods mainly include magnetic separation, electrostatic separation and flotation, which are a series of deashing methods developed according to the physical properties of coal itself, but the efficiency of sorting and ash removal is low; chemical deashing methods mainly react with acidic and alkaline reagents with inorganic minerals in coal to generate soluble products for leaching, thereby achieving the purpose of deashing, with high removal efficiency, but high operating costs, complex production processes, serious corrosion of equipment by reaction reagents, and large environmental pollution of deashing waste liquid; physical-chemical deashing methods combine the advantages of physical and chemical deashing methods, and have better deashing effects, but there are too many restrictions on industrial implementation, and most experimental conditions are still in the laboratory stage.
[0004] The currently used deashing methods cannot meet the needs of deep deashing, and often require a combination of multiple methods, such as HCl and HF solution deashing; or the use of a large number of reagents to improve the deashing effect. However, this simple addition or use of a large number of reagents often leads to a significant increase in operating costs and cannot fully tap the deashing potential of each.
[0005] In summary, in the conventional coal deashing process, in order to achieve the purpose of deep deashing, it is often necessary to use multiple deashing methods in combination, or use a large amount of deashing reagents, which greatly increases the deashing cost and fails to give full play to the potential of each deashing method. Therefore, it is urgent to develop a new coal deashing method to reduce the deashing cost and improve the deashing efficiency. Summary of the invention
[0006] The object of the present invention is to provide a carbon material and a method for deep deashing based on the cascaded deashing of coal, coke and activated carbon, so as to solve the technical problems of complex process and high cost of the existing deep deashing methods.
[0007] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a method for deep deashing of a carbon material based on the cascaded deashing of coal, coke and activated carbon, comprising the following steps: Dry and grind the coal, mix it with a weak acid solution, heat it to a first preset temperature and keep it warm for a first preset time, and then filter and dry to obtain an initial residue; Carbonize the initial residue to obtain pyrolytic coke; Mix the pyrolytic coke with a strong acid solution, heat it to a second preset temperature and keep it warm for a second preset time, and then filter and dry to obtain a secondary residue; Mix the secondary residue with an activator to prepare activated carbon; Mix the activated carbon with a strong base solution, heat it to a third preset temperature and keep it warm for a third preset time, and then filter to obtain deeply deashed activated carbon.
[0008] Further, the process of drying and grinding the coal is: drying and grinding the coal to less than 100 mesh; the weak acid is one or a mixture of two of phosphoric acid and oxalic acid.
[0009] Further, the concentration of the weak acid solution is 1 mol / L to 6 mol / L; the mixing ratio of the coal and the weak acid solution is: 1 g:(50 - 100) mL.
[0010] Further, the first preset temperature is 60 °C to 90 °C; the first preset time is 3 h to 9 h.
[0011] Further, the strong acid is one or a mixture of two of hydrochloric acid and hydrofluoric acid.
[0012] Further, the concentration of the strong acid solution is 1 mol / L to 3 mol / L; the mixing ratio of the pyrolytic coke and the strong acid solution is: 1 g:(20 - 50) mL.
[0013] Further, the second preset temperature is 60 °C to 90 °C; the second preset time is 1 h to 3 h.
[0014] Further, the strong base is one or a mixture of two of KOH and NaOH; the concentration of the strong base solution is 1 mol / L to 3 mol / L; the mixing ratio of the activated carbon and the strong base solution is 1 g:(20 - 50) mL.
[0015] Further, the third preset temperature is 60°C to 90°C; the third preset time is 1 h to 3 h.
[0016] In a second aspect, the present invention provides a carbon material based on the cascade ash removal of coal, coke, and activated carbon, which is prepared according to the deep ash removal method of the carbon material based on the cascade ash removal of coal, coke, and activated carbon described above.
[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a carbon material based on the cascade ash removal of coal, coke, and activated carbon and its deep ash removal method. By soaking in a low-temperature weak acid (such as phosphoric acid, oxalic acid, etc.) solution, a large amount of ash in the coal powder (such as high-content carbonate) is removed. By soaking in a low-temperature strong acid (such as hydrochloric acid, hydrofluoric acid, etc.) solution, the insoluble ash in the pyrolytic coke is removed. By soaking in a low-temperature strong base (such as KOH, NaOH, etc.) solution, the residual ash in the activated carbon (such as Si, etc.) is removed, realizing the cascade and deep removal of ash in the carbon material. The cost of the low-temperature weak acid bath is low, and the degree of aromatic ring condensation of the coal powder is low, which is beneficial for the solute to enter the interior of the particles to dissolve and carry out the ash. The removal of ash in the pyrolytic coke is easier than that in the activated carbon. By using strong acid washing, most of the insoluble inorganic ash can be removed. The remaining insoluble ash in the activated carbon can be dissolved and leached by using a strong base to achieve deep ash removal. Due to the cascade removal method using weak acid solution, strong acid solution, and strong base solution, the usage amounts of strong acid and strong base solutions in the downstream of the ash removal process are significantly reduced, and the potential of strong acid and strong base solutions for removing insoluble ash can also be exerted. The present invention combines the ash removal characteristics of coal, coke, and activated carbon, uses a first-stage weak acid (such as phosphoric acid, oxalic acid, etc.) solution to soak and remove a large amount of ash in the coal, a second-stage strong acid (such as hydrochloric acid, hydrofluoric acid, etc.) solution to soak and remove the insoluble ash in the coke, and a third-stage strong base (such as KOH, NaOH, etc.) solution to soak and remove the acid-insoluble ash remaining in the activated carbon. The three-stage ash removal methods are organically combined to achieve the cascade and deep removal of ash in the carbon material. Description of the Drawings
[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.
[0019] Figure 1 It is a flowchart of the deep ash removal method of the carbon material based on the cascade ash removal of coal, coke, and activated carbon of the present invention; Figure 2a It is a schematic diagram of the residual ash content in the activated carbon after different ash removal methods in Example 1 of the present invention; Figure 2b Schematic diagram of the content of residual Al element in activated carbon after different deashing methods are adopted in Example 1 of the present invention; Figure 2c Schematic diagram of the content of residual Ca element in activated carbon after different deashing methods are adopted in Example 1 of the present invention; Figure 2d Schematic diagram of the content of residual K element in activated carbon after different deashing methods are adopted in Example 1 of the present invention; Figure 2e Schematic diagram of the content of residual Mg in activated carbon after different deashing methods are adopted in Example 1 of the present invention; Figure 2f Schematic diagram of the content of residual Si in activated carbon after different deashing methods are adopted in Example 1 of the present invention; Figure 2g Schematic diagram of the content of residual Fe element in activated carbon after different deashing methods are adopted in Example 1 of the present invention. Detailed implementation manners
[0020] To enable those skilled in the art to understand the features and effects of the present invention, the following provides 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. In case of conflicts, the definition in this specification shall prevail.
[0021] 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.
[0022] 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 brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges shall be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).
[0023] In this article, unless otherwise specified, terms such as "comprising", "including", "containing", "having", or similar terms cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A only comprises a".
[0024] In this article, for the sake of brevity of description, all possible combinations of all technical features in each embodiment or example are not 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 as the scope described in this specification.
[0025] The present invention will be further described in detail below with reference to the accompanying drawings: Refer to Figure 1 , an embodiment of the present invention discloses a method for deep deashing of carbon materials based on cascade deashing of coal, coke and activated carbon, comprising the following steps: Step 1: After drying and grinding coal, mix it with a weak acid solution, heat it to a first preset temperature and keep it warm for a first preset time, then filter and dry to obtain an initial residue; In this step, dry and grind the coal to less than 100 mesh, then mix it with a weak acid (such as phosphoric acid, oxalic acid, etc.) solution with a concentration of 1 - 6 mol / L according to a solid - liquid ratio of 1 g: 50 - 100 mL, heat it to 60 - 90 °C and keep it for 3 - 9 h; filter and dry to obtain the initial residue.
[0026] Step 2: Carbonize the initial residue to obtain pyrolytic coke; In this step, heat - carbonize the initial residue in an inert atmosphere to obtain pyrolytic coke.
[0027] Step 3: Mix the pyrolytic coke with a strong acid solution, heat it to a second preset temperature and keep it warm for a second preset time, then filter and dry to obtain a secondary residue; In this step, mix the above - mentioned pyrolytic coke with a strong acid (such as hydrochloric acid, hydrofluoric acid, etc.) solution with a concentration of 1 - 3 mol / L according to a solid - liquid ratio of 1 g: 20 - 50 mL, heat it to 60 - 90 °C and keep it for 1 - 3 h; filter and dry to obtain the secondary residue.
[0028] Step 4: Mix the secondary residue with an activator to prepare activated carbon; Step 5: Mix the activated carbon with a strong base solution, heat it to a third preset temperature and keep it warm for a third preset time, then filter to obtain deeply de - ashed activated carbon.
[0029] In this embodiment, through multi-step cascade treatment such as mixing coal after drying and grinding with a weak acid solution, carbonizing the initial residue, mixing the pyrolysis coke with a strong acid solution, mixing the secondary residue with an activator to prepare activated carbon, and mixing the activated carbon with a strong base solution, the ash in coal and its derived carbon materials is gradually removed. Compared with a single ash removal method, it can remove ash in different forms and bonding states more comprehensively and deeply, significantly improving the purity of the carbon materials. According to the characteristics of ash in coal and its derived carbon materials at different treatment stages, weak acids, strong acids, and strong base solutions are reasonably selected for treatment. The weak acid solution removes some easily reactive ash in the initial stage; the strong acid solution further treats the pyrolysis coke to remove more insoluble ash; the strong base solution deeply removes specific ash in the activated carbon. This method of selecting different acid and base solutions according to the ash characteristics at different stages improves the ash removal efficiency and reduces the treatment time and cost. In addition, this method makes full use of coal resources. Through gradual transformation and ash removal treatment, not only a highly de-ashed activated carbon product is obtained, but also the efficient utilization of coal resources is realized. At the same time, the intermediate products (such as pyrolysis coke) generated during the treatment process can also be used as raw materials for other industrial processes, further enhancing the economic benefits of the entire process. Using the chemical ash removal method, compared with some physical ash removal methods, it reduces dust emissions and energy consumption. At the same time, the reasonable selection of acid and base solutions and treatment conditions helps to reduce the difficulty and cost of waste liquid treatment and reduce environmental pollution, meeting environmental protection requirements.
[0030] In this step, the above-mentioned activated carbon is mixed with a strong base (such as KOH, NaOH, etc.) solution with a concentration of 1 - 3 mol / L according to a solid-liquid ratio of 1 g : 20 - 50 mL, heated to 60 - 90 °C and maintained for 1 - 3 h; the highly de-ashed activated carbon is obtained by filtration.
[0031] An embodiment of the present invention discloses a carbon material based on the cascaded deashing of coal, coke, and activated carbon, which is prepared according to the method for deep deashing of the carbon material based on the cascaded deashing of coal, coke, and activated carbon. Aiming at the problems of difficult deep deashing of carbon materials, complex processes, and difficult processes, etc., the present invention combines the characteristics of ash removal in coal, coke, and activated carbon, and uses a weak acid solution (such as phosphoric acid, oxalic acid, etc.) of the first level to soak and remove a large amount of ash in coal, and a strong acid solution (such as hydrochloric acid, hydrofluoric acid, etc.) of the second level to soak and remove the insoluble ash in coke, and a strong base solution (such as KOH, NaOH, etc.) of the third level to soak and remove the acid-insoluble ash remaining in the activated carbon. The three-level deashing methods are organically combined to achieve the cascaded and deep removal of ash in the carbon material. The obtained high-purity carbon material, with its excellent purity characteristics, can effectively avoid various side reactions caused by impurities in high-temperature environments or complex electrochemical systems, thereby significantly improving the overall stability of the material. In high-temperature scenarios, impurities (such as metal oxides and inorganic salts such as silicon, aluminum, and iron) in traditional carbon materials often react chemically with the surrounding medium, resulting in the destruction of the material structure, the decline of performance, and even failure. However, through deep deashing treatment, the high-purity carbon material reduces the impurity content to an extremely low level (usually the ash content is less than 0.5%), fundamentally eliminating the possibility of impurities participating in high-temperature reactions, and ensuring that the material can still maintain stable physical and chemical properties under high-temperature conditions.
[0032] In an electrochemical environment, especially during the charge-discharge cycle of a battery, the high-purity carbon material also exhibits excellent stability. Impurities in traditional carbon materials are prone to side reactions such as electrochemical corrosion, precipitation, or migration under the action of an electric field. These reactions not only consume the active substances in the battery but also form a passivation layer or cause structural collapse on the electrode surface, thereby accelerating the decay of battery performance. However, due to the extremely low impurity content, the high-purity carbon material hardly participates in electrochemical reactions, effectively avoiding the occurrence of these side reactions.
[0033] The following further elaborates the present invention 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.
[0034] Conventional instrument equipment in the art is used in the following embodiments. For the experimental methods without specific conditions noted in the following embodiments, they are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Various raw materials are used in the following embodiments. Unless otherwise stated, commercially available products are used, and their specifications are the conventional specifications in the art. In the specification of the present invention and the following embodiments, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.
[0035] Example 1: (1) Dry and grind coal to less than 100 mesh, then mix it with 6 mol / L oxalic acid (OA) solution at a solid-liquid ratio of 1 g:50 mL, heat it to 60 °C and maintain for 6 h; filter and dry to obtain the initial residue.
[0036] (2) Heat and carbonize the initial residue under an inert atmosphere to obtain pyrolytic coke.
[0037] (3) Mix the above pyrolytic coke with 1 mol / L strong acid (hydrochloric acid, hydrofluoric acid, etc.) solution at a solid-liquid ratio of 1 g:30 mL, heat it to 60 °C and maintain for 3 h; filter and dry to obtain the secondary residue.
[0038] (4) Mix the above secondary residue with an activator to prepare activated carbon.
[0039] (5) Mix the above activated carbon with 1 mol / L strong base (KOH, NaOH, etc.) solution at a solid-liquid ratio of 1 g:30 mL, heat it to 60 °C and maintain for 3 h; filter to obtain deeply deashed activated carbon.
[0040] See Figure 2a 、 Figure 2b 、 Figure 2c 、 Figure 2d 、 Figure 2e 、 Figure 2f and Figure 2g to compare the contents of residual ash, Al element, Ca element, K element, Mg, Si, Fe element, etc. in the activated carbon after different deashing methods.
[0041] It can be seen from the figure that weak acid deashing (AC-OA) can remove nearly 46% of the ash, acid washing can remove nearly 77% of the ash, and alkali washing can remove 75% of the ash. Combining the three for cascade deashing can remove 96% of the ash.
[0042] The main reason is that weak acid deashing can remove some Al, a small amount of K, and some Fe, while the removal ranges of acid and alkali are exactly complementary, which is beneficial to the removal of ash elements in a larger range. The cascade combination of the three can not only achieve deep removal of ash in carbon materials, give full play to the potential of strong acid and strong base solutions for removing insoluble ash, but also reduce the dosage of strong acid and strong base.
[0043] Example 2: (1) Dry and grind coal to less than 100 mesh, then mix it with 2 mol / L oxalic acid (OA) solution at a solid-liquid ratio of 1 g:80 mL, heat it to 80 °C and maintain for 7 h; filter and dry to obtain the initial residue.
[0044] (2) Heat and carbonize the initial residue under an inert atmosphere to obtain pyrolytic coke.
[0045] (3) Mix the above pyrolytic char with a 3 mol / L strong acid (such as hydrochloric acid, hydrofluoric acid, etc.) solution at a solid-liquid ratio of 1 g:20 mL, heat it to 80 °C and keep it for 2 h; filter and dry to obtain the secondary residue.
[0046] (4) Mix the above secondary residue with an activator to prepare activated carbon.
[0047] (5) Mix the above activated carbon with a 2 mol / L strong base (such as KOH, NaOH, etc.) solution at a solid-liquid ratio of 1 g:40 mL, heat it to 70 °C and keep it for 2 h; filter to obtain the deeply deashed activated carbon.
[0048] Example 3: (1) Dry and grind the coal to below 100 mesh, then mix it with a 4 mol / L oxalic acid (OA) solution at a solid-liquid ratio of 1 g:70 mL, heat it to 90 °C and keep it for 6 h; filter and dry to obtain the initial residue.
[0049] (2) Carry out temperature-rising carbonization of the initial residue under an inert atmosphere to obtain pyrolytic char.
[0050] (3) Mix the above pyrolytic char with a 2 mol / L strong acid (such as hydrochloric acid, hydrofluoric acid, etc.) solution at a solid-liquid ratio of 1 g:30 mL, heat it to 70 °C and keep it for 1 h; filter and dry to obtain the secondary residue.
[0051] (4) Mix the above secondary residue with an activator to prepare activated carbon.
[0052] (5) Mix the above activated carbon with a 3 mol / L strong base (such as KOH, NaOH, etc.) solution at a solid-liquid ratio of 1 g:50 mL, heat it to 90 °C and keep it for 2 h; filter to obtain the deeply deashed activated carbon.
[0053] Example 4: (1) Dry and grind the coal to below 100 mesh, then mix it with a 5 mol / L oxalic acid (OA) solution at a solid-liquid ratio of 1 g:60 mL, heat it to 70 °C and keep it for 9 h; filter and dry to obtain the initial residue.
[0054] (2) Carry out temperature-rising carbonization of the initial residue under an inert atmosphere to obtain pyrolytic char.
[0055] (3) Mix the above pyrolytic char with a 1 mol / L strong acid (such as hydrochloric acid, hydrofluoric acid, etc.) solution at a solid-liquid ratio of 1 g:50 mL, heat it to 90 °C and keep it for 3 h; filter and dry to obtain the secondary residue.
[0056] (4) Mix the above secondary residue with an activator to prepare activated carbon.
[0057] (5) Mix the above activated carbon with a 3 mol / L strong base (such as KOH, NaOH, etc.) solution at a solid-liquid ratio of 1 g:30 mL, heat up to 80 °C and maintain for 1 h; filter to obtain deeply deashed activated carbon.
[0058] Example 5: (1) Dry and grind the coal to below 100 mesh, then mix it with a 3 mol / L oxalic acid (OA) solution at a solid-liquid ratio of 1 g:100 mL, heat up to 80 °C and maintain for 5 h; filter and dry to obtain the initial residue.
[0059] (2) Heat up and carbonize the initial residue in an inert atmosphere to obtain pyrolytic coke.
[0060] (3) Mix the above pyrolytic coke with a 3 mol / L strong acid (such as hydrochloric acid, hydrofluoric acid, etc.) solution at a solid-liquid ratio of 1 g:40 mL, heat up to 70 °C and maintain for 2 h; filter and dry to obtain the secondary residue.
[0061] (4) Mix the above secondary residue with an activator to prepare activated carbon.
[0062] (5) Mix the above activated carbon with a 2 mol / L strong base (such as KOH, NaOH, etc.) solution at a solid-liquid ratio of 1 g:40 mL, heat up to 70 °C and maintain for 3 h; filter to obtain deeply deashed activated carbon.
[0063] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A method for deep deashing of carbon materials based on cascade deashing of coal, coke and activated carbon, characterized in that, It includes the following steps: After drying and grinding the coal, mix it with a weak acid solution. After heating to the first preset temperature and holding for the first preset time, filter and dry to obtain the initial residue; Carry out carbonization on the initial residue to obtain pyrolytic coke; Mix the pyrolytic coke with a strong acid solution. After heating to the second preset temperature and holding for the second preset time, filter and dry to obtain the secondary residue; Mix the secondary residue with an activator to prepare activated carbon; Mix the activated carbon with a strong base solution. After heating to the third preset temperature and holding for the third preset time, filter to obtain the deeply deashed activated carbon.
2. A method for deep deashing of carbon materials based on cascaded deashing of coal, coke and activated carbon according to claim 1, characterized in that, The process of drying and grinding the coal is: drying and grinding the coal to below 100 mesh; the weak acid is one or a mixture of two of phosphoric acid and oxalic acid.
3. A method for deep deashing of carbon materials based on cascaded deashing of coal, coke and activated carbon according to claim 1, characterized in that, The concentration of the weak acid solution is 1 mol / L to 6 mol / L; the mixing ratio of the coal and the weak acid solution is: 1 g:(50 - 100) mL.
4. A method for deep deashing of carbon materials based on cascade deashing of coal, coke and activated carbon according to claim 1, characterized in that, The first preset temperature is 60°C to 90°C; the first preset time is 3 h to 9 h.
5. A method for deep deashing of carbon materials based on cascaded deashing of coal, coke and activated carbon according to claim 1, characterized in that, The strong acid is one or a mixture of two of hydrochloric acid and hydrofluoric acid.
6. A method for deep deashing of carbon materials based on cascade deashing of coal, coke and activated carbon according to claim 1, characterized in that, The concentration of the strong acid solution is 1 mol / L to 3 mol / L; the mixing ratio of the pyrolytic coke and the strong acid solution is: 1 g:(20 - 50) mL.
7. A method for deep desliming of carbon materials based on cascade desliming of coal, coke and activated carbon according to claim 1, characterized in that, The second preset temperature is 60°C to 90°C; the second preset time is 1 h to 3 h.
8. A method for deep deashing of carbon materials based on cascade deashing of coal, coke and activated carbon according to claim 1, characterized in that, The strong base is one or a mixture of two of KOH and NaOH; the concentration of the strong base solution is 1 mol / L to 3 mol / L; the mixing ratio of the activated carbon and the strong base solution is 1 g:(20 - 50) mL.
9. A method for deep deashing of carbon materials based on cascade deashing of coal, coke and activated carbon according to claim 1, characterized in that, The third preset temperature is 60°C to 90°C; the third preset time is 1 h to 3 h.
10. A carbon material based on the stepwise deashing of coal, coke and activated carbon, characterized in that, It is prepared by the method for deep deashing of carbon materials based on the stepwise deashing of coal, coke and activated carbon according to any one of claims 1 to 9.