Coal-based briquetted activated carbon and method for producing the same

Abstract

The application provides a coal-based briquetted activated carbon and a preparation method thereof. The method comprises the following steps: mixing long flame coal and coking coal to obtain raw coal, wherein the long flame coal and the coking coal are included in the raw coal at 75-95% and 5-25% by weight percentage respectively; sequentially performing briquetting and granulation on the raw coal to obtain coal particles; and sequentially performing oxidation, carbonization and activation treatment on the coal particles to obtain the coal-based briquetted activated carbon. The long flame coal and the coking coal are used as raw materials to perform coal blending, and after granulation, oxidation, carbonization and activation treatment, the coal-based briquetted activated carbon product with qualified indexes is obtained. The long flame coal and the coking coal with specific proportions are used to perform coal blending, the strength of the activated carbon is improved by introducing the coking coal, and the development of the pore of the activated carbon is promoted by introducing the long flame coal, so that the properties of the above raw materials are combined well, and the activated carbon product can have high strength and good adsorption performance.

Description

Technical Field

[0001] This invention relates to the field of activated carbon preparation technology, and more specifically, to a coal-based briquetted activated carbon and its preparation method. Background Technology

[0002] Activated carbon products prepared from pure long-flame coal exhibit excellent adsorption performance but low strength. Activated carbon products prepared from pure coking coal exhibit excellent strength, maintaining a strength greater than 95% even after prolonged activation, but their pore development is weak, resulting in iodine adsorption values ​​<1000 mg / g. The low degree of coalification within long-flame coal leads to a gradual decrease in product strength during briquetting, oxygen carbonization, and activation processes, making it rarely used alone for activated carbon production. While coking coal provides some binding properties, improving product strength, it hinders the pore-forming reaction during activation, making it difficult to produce products with satisfactory adsorption performance.

[0003] Patent CN 105858655 A discloses a method for preparing coal-based briquetted activated carbon with adjusted bulk density, using a combination of long-flame coal and gas-rich coal to prepare activated carbon; Patent CN 105905898 A discloses a method for preparing coal-based briquetted activated carbon with high methylene blue value, using highly active long-flame coal and caking gas-rich coal to prepare activated carbon. However, both of the above methods use strongly caking gas-rich coal and require the use of anthracite or bitumen for blending, resulting in complex raw materials and high costs. Summary of the Invention

[0004] The main objective of this invention is to provide a coal-based briquetted activated carbon and its preparation method, so as to solve the problem that the raw materials used in the preparation of briquetted activated carbon in the prior art are limited and cannot achieve both high strength and good adsorption performance.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for preparing coal-based briquetted activated carbon is provided, comprising the following steps: Step S1, mixing long-flame coal and coking coal to obtain raw coal; Step S2, sequentially briquetting and granulating the raw coal to obtain coal particles; Step S3, oxidizing the coal particles to obtain oxidized material; then, carbonizing the oxidized material to obtain carbonized material; Step S4, activating the carbonized material to obtain coal-based briquetted activated carbon; wherein, by weight percentage, the raw coal comprises 75-95% long-flame coal and 5-25% coking coal.

[0006] Furthermore, the volatile matter content of long-flame coal is ≥35wt%, the ash content is ≤4wt%, and the caking index is ≥10.

[0007] Furthermore, the volatile matter content of the coking coal is ≤35wt%, the ash content is ≤10wt%, and the caking index is ≥30.

[0008] Furthermore, step S1 also includes a step of grinding the raw coal; preferably, the weight percentage of raw coal with a particle size <44μm in the ground raw coal is ≥70%, more preferably 75-80%.

[0009] Furthermore, in step S2, the pressure for briquetting is 20-30 MPa; preferably, the particle size of the coal particles is 1-10 mm, more preferably 3-8 mm.

[0010] Further, in step S3, the temperature is increased to 200-255°C at a heating rate of 3-5°C / min for oxidation treatment, and the oxidation treatment time is 2-4 hours; preferably, the oxidation treatment temperature is 240-255°C; more preferably, the oxidation treatment process is carried out in an oxidizing atmosphere, and the oxygen volume percentage in the oxidizing atmosphere is 6-12 vol%.

[0011] Further, in step S3, the temperature is increased to 500-555°C at a heating rate of 8-10°C / min for carbonization treatment, and the carbonization treatment time is 2-3 hours; preferably, the carbonization treatment process is carried out in a carbonization atmosphere, and the oxygen volume percentage in the carbonization atmosphere is ≤3 vol%.

[0012] Further, in step S4, the temperature is increased to 900-920℃ at a heating rate of ≤20℃ / min for activation treatment, and the activation treatment time is 4-5h.

[0013] Furthermore, in step S4, the carbonized material is heated to 880-900°C and then an activator is introduced for activation treatment.

[0014] According to another aspect of the present invention, a coal-based briquetted activated carbon is provided, which is obtained by the preparation method described above, and the coal-based briquetted activated carbon has a roller strength >93%, ash content <13%, bulk density >450g / L, methylene blue adsorption value >180mg / g, and iodine adsorption value >1000mg / g.

[0015] By applying the technical solution of this invention, long-flame coal and coking coal are used as raw materials for coal blending. After granulation, oxidation, carbonization, and activation treatment, a qualified coal-based briquetted activated carbon product is obtained. This invention uses a specific ratio of long-flame coal and coking coal to prepare coal-based briquetted activated carbon. The introduction of coking coal enhances the strength of the activated carbon, while the introduction of long-flame coal, with its higher activity, further promotes the development of the activated carbon pores. This effectively combines the properties and synergistic effects of the aforementioned raw materials, ensuring that the prepared coal-based briquetted activated carbon product can achieve both high strength and good adsorption performance. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0017] As described in the background section of this invention, existing technologies suffer from the problem of using a single raw material and failing to simultaneously achieve high strength and good adsorption performance when preparing briquetted activated carbon. To address this issue, in a typical embodiment of this invention, a method for preparing coal-based briquetted activated carbon is provided, comprising the following steps: Step S1, mixing long-flame coal and coking coal to obtain raw coal; Step S2, sequentially briquetting and granulating the raw coal to obtain coal particles; Step S3, oxidizing the coal particles to obtain oxidized material; then carbonizing the oxidized material to obtain carbonized material; Step S4, activating the carbonized material to obtain coal-based briquetted activated carbon; wherein, by weight percentage, the raw coal comprises 75-95% long-flame coal and 5-25% coking coal.

[0018] This invention first mixes long-flame coal and coking coal to obtain raw coal, then sequentially briquettes and granulates the resulting coal particles. These particles are then subjected to oxidation, carbonization, and activation treatments to obtain coal-based briquetted activated carbon. This invention utilizes a specific ratio of long-flame coal and coking coal to prepare coal-based briquetted activated carbon. The long-flame coal is a young coal type with a low degree of internal coalification and high activity, making it easy to expand pores. When used in combination with the coking coal of this invention, it increases the activation reaction activity, facilitating pore formation in the activated carbon and thus improving its iodine adsorption value. The coking coal is a strongly binding coal type. Adding coking coal not only increases the adhesion between coal powder particles and improves the strength of the briquetted material, but also, when used in combination with the long-flame coal of this invention, the introduction of coking coal is beneficial for the subsequent formation of the carbon skeleton and the improvement of product strength. The method of this invention effectively combines the properties and synergistic effects of long-flame coal and coking coal raw materials, resulting in coal-based briquetted activated carbon that balances high strength and good adsorption performance.

[0019] When the amount of long-flame coal in the raw coal is less than 75% and the amount of coking coal is more than 25%, the porosity of the coal-based briquetted activated carbon product is weak, resulting in poor adsorption capacity. Conversely, when the amount of long-flame coal in the raw coal is more than 95% and the amount of coking coal is less than 5%, the strength of the coal-based briquetted activated carbon product is low. Therefore, this invention limits the raw coal to include 75-95% long-flame coal and 5-25% coking coal. Typically, but not limitingly, the amount of long-flame coal in the raw coal can be 75%, 80%, 85%, 90%, 95%, or any combination of two values, and the amount of coking coal can be 5%, 10%, 15%, 20%, 25%, or any combination of two values.

[0020] To further utilize the high activity of long-flame coal to promote the development of activated carbon pores, in a preferred embodiment, the long-flame coal has a volatile matter content ≥35wt%, an ash content ≤4wt%, and a caking index ≥10; preferably, the long-flame coal includes Toksun Black Mountain coal to better achieve the purpose of the invention. Typically, but not limitingly, the volatile matter content of the long-flame coal can be 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, or 40wt%, or any range of two such values; the ash content can be 1wt%, 2wt%, 3wt%, or 4wt%, or any range of two such values; and the caking index can be 10, 11, 12, 13, 14, or 15, or any range of two such values.

[0021] To further utilize the strong caking properties of coking coal to enhance the strength of activated carbon, in a preferred embodiment, the volatile matter content of the coking coal is ≤35wt%, the ash content is ≤10wt%, and the caking index is ≥30. Preferably, the coking coal includes Hami Heiyanquan coal to better achieve the purpose of the invention. Typically, but not limitingly, the volatile matter content of the coking coal can be 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, or 35wt%, or any two of these values; the ash content can be 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, or 10wt%, or any two of these values; and the caking index can be 30, 31, 32, 33, 34, or 35%, or any two of these values.

[0022] In a preferred embodiment, step S1 further includes grinding the raw coal. Preferably, the weight percentage of raw coal with a particle size <44μm in the ground raw coal is ≥70%; more preferably 75-80%. Specific coal blending and grinding processes are well known in the art. A certain amount of long-flame coal and coking coal can be mixed evenly and ground into a fine powder with a specific particle size distribution, for example, through 180-mesh, 200-mesh, or 325-mesh Taylor standard sieves. Those skilled in the art understand that the pulverized raw coal can be sieved using appropriate standard sieves to obtain coal powder with the aforementioned particle size distribution. These parameters can achieve a reasonable gradation of coal powder with different particle sizes during the molding process, ensuring molding strength while maintaining a good initial void distribution, which is beneficial for the subsequent entry of the activation medium. It also allows for more uniform mixing of the two raw materials, facilitating the subsequent briquetting process.

[0023] In the preparation of coal-based briquetted activated carbon, the molding and crushing / granulation of coal powder are conventional processes in the field. For example, coal powder can be molded using a roller briquetting machine, crushed using a crusher, and then screened to obtain coal particles with a certain particle size range. In a preferred embodiment, in step S2, the pressure of briquetting is 20-30 MPa, which can further improve the preparation efficiency. Crushing and granulation includes crushing and screening to obtain coal particles with a roller strength >90% and a particle size preferably 1-10 mm, more preferably 3-8 mm.

[0024] In a preferred embodiment, in step S3, the temperature is increased to 200-255°C at a heating rate of 3-5°C / min for oxidation treatment, and the oxidation treatment time is 2-4 hours. Preferably, the oxidation treatment temperature is 240-255°C. More preferably, the oxidation treatment is carried out in an oxidizing atmosphere, and the oxygen volume percentage in the oxidizing atmosphere is 6-12 vol%. For example, an oxidizing atmosphere is formed by using a mixture of nitrogen and air as an oxidant. Under the above oxidation conditions, the oxidation of the material can be controlled to a relatively light degree, and some oxygen can be combined with the coal to form a low-adhesion oxide film on the coal surface, thereby reducing the coal's adhesion and expansion properties, and also accelerating the activation reaction rate.

[0025] After carbonization, the carbon atoms in the compound combine to form a porous carbon structure with certain adsorption capacity. These porous structures will form a more developed microporous structure during the activation process. To further improve the adsorption performance of activated carbon, in a preferred embodiment, in step S3, the temperature is increased to 500-555°C at a heating rate of 8-10°C / min for carbonization treatment, and the carbonization time is 2-3 hours. Preferably, the carbonization process is carried out in a carbonization atmosphere with an oxygen volume percentage ≤3 vol%. More preferably, the roller strength of the carbonized material is >96%. Compared with traditional carbonization reactions, the above carbonization conditions can better combine the characteristics of the raw coal and are more conducive to subsequent activation and pore formation.

[0026] In a preferred embodiment, in step S4, the temperature is increased to 900-920°C at a heating rate of ≤20°C / min for activation treatment, and the activation treatment time is 4-5 hours. Preferably, the activator is water vapor, which can further improve the activation effect, increase the adsorption capacity while ensuring the strength of activated carbon, and prevent over-activation of the surface.

[0027] Preheating can make the activation of carbonized material more uniform. In a preferred embodiment, in step S4, the carbonized material is heated to 880-900°C and then an activator is introduced for activation treatment.

[0028] In another typical embodiment of the present invention, a coal-based briquetted activated carbon is also provided, which is obtained by the preparation method of the present invention, and the coal-based briquetted activated carbon has a roller strength >93%, ash content <13%, bulk density >450g / L, methylene blue adsorption value >180mg / g, and iodine adsorption value >1000mg / g.

[0029] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0030] Example 1

[0031] By weight percentage, the raw coal includes 80% bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 20% raw coal from Heiyanquan Coal Mine in Hami. The bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, has a volatile matter content of 38%, an ash content of 3%, and a caking index of 12. The raw coal from Heiyanquan Coal Mine in Hami has a volatile matter content of 34%, an ash content of 9%, and a caking index of 31.

[0032] The two raw materials mentioned above are mixed and added to a ball mill for grinding. The fineness of the grinding reaches 325 mesh with a passing rate (i.e., particle size < 44μm) of 70%. Then, the coal powder is briquetteed at 25 MPa using a roller briquetting machine. Then, it is crushed using a crusher and then screened to obtain coal particles with a particle size in the range of 3 to 8 mm. The roller strength of the coal particles is greater than 90%.

[0033] Coal particles were oxidized at 250℃ for 3 hours in an oxidizing atmosphere with an oxygen volume percentage of 9 vol%, with a heating rate of 4℃ / min, to obtain oxidized material; then, the oxidized material was carbonized at 550℃ for 2.5 hours in a carbonizing atmosphere with an oxygen volume percentage of ≤3 vol%, with a heating rate of 9℃ / min, to obtain carbonized material, with a roller strength greater than 96% for the carbonized material.

[0034] After heating the carbonized material to 890℃, distilled water was introduced at a rate of 120 drops / min, and the material was activated in a small activation furnace at 920℃ for 300 minutes with a heating rate of 18℃ / min to obtain coal-based briquetted activated carbon.

[0035] Example 2

[0036] The only difference between Example 2 and Example 1 is that, by weight percentage, the raw coal includes 75% bituminous coal from the Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 25% raw coal from the Heiyanquan Coal Mine in Hami.

[0037] Example 3

[0038] The only difference between Example 3 and Example 1 is that, by weight percentage, the raw coal includes 95% bituminous coal from the Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 5% raw coal from the Heiyanquan Coal Mine in Hami.

[0039] Example 4

[0040] The only difference between Example 4 and Example 1 is that, by weight percentage, the raw coal includes 70% bituminous coal from the Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 30% raw coal from the Heiyanquan Coal Mine in Hami.

[0041] Example 5

[0042] The only difference between Example 5 and Example 1 is that, by weight percentage, the raw coal includes 98% bituminous coal from the Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 2% raw coal from the Heiyanquan Coal Mine in Hami.

[0043] Example 6

[0044] By weight percentage, the raw coal includes 80% bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 20% raw coal from Heiyanquan Coal Mine in Hami. The bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, has a volatile matter content of 38%, an ash content of 3%, and a caking index of 12. The raw coal from Heiyanquan Coal Mine in Hami has a volatile matter content of 34%, an ash content of 9%, and a caking index of 31.

[0045] The two raw materials mentioned above are mixed and added to a ball mill for grinding. The fineness of the grinding reaches 325 mesh with a passing rate (i.e., particle size < 44μm) of 70%. Then, the coal powder is briquetteed at 25 MPa using a roller briquetting machine. Then, it is crushed using a crusher and then screened to obtain coal particles with a particle size in the range of 3 to 8 mm. The roller strength of the coal particles is greater than 90%.

[0046] Coal particles were oxidized at 240℃ for 4 hours in an oxidizing atmosphere with an oxygen volume percentage of 9 vol%, with a heating rate of 4℃ / min, to obtain oxidized material; then, the oxidized material was carbonized at 550℃ for 2.5 hours in a carbonizing atmosphere with an oxygen volume percentage of ≤3 vol%, with a heating rate of 9℃ / min, to obtain carbonized material, with a roller strength greater than 96% for the carbonized material.

[0047] After heating the carbonized material to 880℃, distilled water was introduced at a rate of 120 drops / minute. The material was then activated in a small activation furnace at 900℃ for 240 minutes with a heating rate of 20℃ / min to obtain coal-based briquetted activated carbon.

[0048] Example 7

[0049] By weight percentage, the raw coal includes 80% bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 20% raw coal from Heiyanquan Coal Mine in Hami. The bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, has a volatile matter content of 38%, an ash content of 3%, and a caking index of 12. The raw coal from Heiyanquan Coal Mine in Hami has a volatile matter content of 34%, an ash content of 9%, and a caking index of 31.

[0050] The two raw materials mentioned above are mixed and added to a ball mill for grinding. The fineness of the grinding reaches 325 mesh with a passing rate (i.e., particle size < 44μm) of 70%. Then, the coal powder is briquetteed at 25 MPa using a roller briquetting machine. Then, it is crushed using a crusher and then screened to obtain coal particles with a particle size in the range of 3 to 8 mm. The roller strength of the coal particles is greater than 90%.

[0051] Coal particles were oxidized at 255℃ for 4 hours in an oxidizing atmosphere with an oxygen volume percentage of 9 vol%, with a heating rate of 4℃ / min, to obtain oxidized material; then, the oxidized material was carbonized at 550℃ for 2.5 hours in a carbonizing atmosphere with an oxygen volume percentage of ≤3 vol%, with a heating rate of 9℃ / min, to obtain carbonized material, with a roller strength greater than 96% for the carbonized material.

[0052] After heating the carbonized material to 900℃, distilled water was introduced at a rate of 120 drops / minute, and the material was activated in a small activation furnace at 920℃ for 300 minutes with a heating rate of 20℃ / min to obtain coal-based briquetted activated carbon.

[0053] Example 8

[0054] By weight percentage, the raw coal includes 80% bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 20% raw coal from Heiyanquan Coal Mine in Hami. The bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, has a volatile matter content of 38%, an ash content of 3%, and a caking index of 12. The raw coal from Heiyanquan Coal Mine in Hami has a volatile matter content of 34%, an ash content of 9%, and a caking index of 31.

[0055] The two raw materials mentioned above are mixed and added to a ball mill for grinding. The fineness of the grinding reaches 325 mesh with a passing rate (i.e., particle size < 44μm) of 70%. Then, the coal powder is briquetteed at 20 MPa using a roller briquetting machine. Then, it is crushed using a crusher and then screened to obtain coal particles with a particle size in the range of 1 to 10 mm. The roller strength of the coal particles is greater than 90%.

[0056] Coal particles were oxidized at 200℃ for 2 hours in an oxidizing atmosphere with an oxygen volume percentage of 12 vol%, with a heating rate of 3℃ / min, to obtain oxidized material; then, the oxidized material was carbonized at 500℃ for 2 hours in a carbonization atmosphere with an oxygen volume percentage of ≤3 vol%, with a heating rate of 8℃ / min, to obtain carbonized material, and the strength of the carbonized material roller was greater than 96%.

[0057] After heating the carbonized material to 890℃, distilled water was introduced at a rate of 120 drops / min, and the material was activated in a small activation furnace at 920℃ for 300 minutes with a heating rate of 18℃ / min to obtain coal-based briquetted activated carbon.

[0058] Example 9

[0059] By weight percentage, the raw coal includes 80% bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, and 20% raw coal from Heiyanquan Coal Mine in Hami. The bituminous coal from Guoneng Heishan Coal Mine in Toksun County, Xinjiang, has a volatile matter content of 38%, an ash content of 3%, and a caking index of 12. The raw coal from Heiyanquan Coal Mine in Hami has a volatile matter content of 34%, an ash content of 9%, and a caking index of 31.

[0060] The two raw materials mentioned above are mixed and added to a ball mill for grinding. The fineness of the grinding reaches 325 mesh with a passing rate (i.e., particle size < 44μm) of 70%. Then, the coal powder is briquetteed at 30 MPa using a roller briquetting machine. The briquette is then crushed using a crusher and screened to obtain coal particles with a particle size in the range of 1 to 10 mm. The roller strength of the coal particles is greater than 90%.

[0061] Coal particles were oxidized at 255℃ for 4 hours in an oxidizing atmosphere with an oxygen volume percentage of 6 vol%, with a heating rate of 5℃ / min, to obtain oxidized material; then, the oxidized material was carbonized at 555℃ for 3 hours in a carbonization atmosphere with an oxygen volume percentage of ≤3 vol%, with a heating rate of 10℃ / min, to obtain carbonized material, and the strength of the carbonized material roller was greater than 96%.

[0062] After heating the carbonized material to 890℃, distilled water was introduced at a rate of 120 drops / min, and the material was activated in a small activation furnace at 920℃ for 300 minutes with a heating rate of 18℃ / min to obtain coal-based briquetted activated carbon.

[0063] Comparative Example 1

[0064] The raw coal consists of 80 wt% long-flame coal, 10 wt% non-caking coal, and 10 wt% gas-rich coal. The raw coal is ground in a ball mill for 5 hours, and the pulverized coal is then passed through a 170-mesh sieve to collect the undersize material. The pulverized coal is then briquetteed and granulated to obtain coal particles. These particles undergo oxidation, carbonization, and activation treatments sequentially. The oxidation conditions are: oxidation in an electric converter at a temperature controlled between 220 and 250°C under natural ventilation for 2.5 hours; the carbonization conditions are: after oxidation, the converter is heated to a temperature controlled between 520 and 550°C, and the ventilation holes are sealed, with the material carbonized for 2 hours to obtain carbonized material; the activation conditions are: the temperature in the converter is controlled at approximately 910°C to 930°C, and steam is used as the activation medium for 3.5 hours, with the amount of activation medium being 3.5 times the weight of the carbonized material. The resulting activated carbon is sieved, and particles with a size of 8–30 mesh are collected.

[0065] The coal-based briquetted activated carbon of Examples 1 to 9 and Comparative Example 1 were tested, and the results are shown in Table 1.

[0066] Detection method:

[0067] Drum strength: GB / T 7702.3-2008;

[0068] Ash content: GB / T 7702.15-2008;

[0069] Bulk density: GB / T 7702.4-1997;

[0070] Methylene blue adsorption value: GB / T 7702.6-2008;

[0071] Iodine adsorption value: GB / T 7702.7-2008.

[0072] Table 1

[0073] Roller strength % Ash content % Bulk density g / L methylene blue adsorption value (mg / g) Iodine adsorption value (mg / g) Example 1 97 11.80 539 210 1060 Example 2 97 12.02 525 185 1035 Example 3 93 10.36 460 215 1039 Example 4 93 12.52 507 169 949 Example 5 90 10.28 447 206 1002 Example 6 97 10.98 535 180 1005 Example 7 95 12.30 502 202 1045 Example 8 96 12.03 539 210 1029 Example 9 95 12.12 537 208 1027 Comparative Example 1 85 10.36 542 156 934

[0074] As can be seen from the above, compared with the comparative example, the embodiments of the present invention utilize long-flame coal and coking coal as raw materials for coal blending. After granulation, oxidation, carbonization, and activation treatment, qualified coal-based briquetted activated carbon products are obtained. The preparation of coal-based briquetted activated carbon using a specific ratio of long-flame coal and coking coal enhances the strength of the activated carbon through the introduction of coking coal, while the introduction of long-flame coal, with its higher activity, further promotes the development of activated carbon pores. This effectively combines the properties and synergistic effects of the aforementioned raw materials, ensuring that the prepared coal-based briquetted activated carbon product can achieve both high strength and good adsorption performance. Furthermore, it can be seen that when all process parameters are within the preferred range of the present invention, a better balance between high strength and good adsorption performance can be achieved.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing coal-based briquetted activated carbon, characterized in that, Includes the following steps: Step S1: Mix long-flame coal and coking coal to obtain raw coal; Step S2: The raw coal is sequentially briquetting and granulating to obtain coal particles; Step S3: Oxidize the coal particles to obtain oxidized material; Then, the oxidized material is carbonized to obtain carbonized material; Step S4: Activate the carbonized material to obtain the coal-based briquetted activated carbon; The raw coal comprises, by weight percentage, 75-80% of the long-flame coal and 20-25% of the coking coal. The long-flame coal has a volatile matter content of ≥35wt%, an ash content of ≤4wt%, and a caking index of ≥10; The coking coal has a volatile matter content of ≤35wt%, an ash content of ≤10wt%, and a caking index of ≥30. The coal-based briquetted activated carbon has a roller strength >93%, ash content <13%, bulk density >450g / L, methylene blue adsorption value >180mg / g, and iodine adsorption value >1000mg / g. In step S3, the temperature is increased to 200-255°C at a heating rate of 3-5°C / min for the oxidation treatment, and the oxidation treatment time is 2-4 hours. The oxidation treatment is carried out in an oxidizing atmosphere, and the oxygen volume percentage in the oxidizing atmosphere is 6-12 vol%. In step S3, the carbonization process is carried out by heating to 500-555°C at a heating rate of 8-10°C / min for 2-3 hours; the carbonization process is carried out in a carbonization atmosphere, and the oxygen volume percentage in the carbonization atmosphere is ≤3 vol%. In step S4, the activation treatment is performed by heating to 900-920°C at a heating rate of ≤20°C / min for a duration of 4-5 hours.

2. The preparation method according to claim 1, characterized in that, Step S1 also includes the step of grinding the raw coal.

3. The preparation method according to claim 2, characterized in that, In the ground raw coal, the weight percentage of raw coal with a particle size <44μm is ≥70%.

4. The preparation method according to claim 2, characterized in that, In the ground raw coal, the weight percentage of raw coal with a particle size <44μm is 75-80%.

5. The preparation method according to any one of claims 1 to 4, characterized in that, In step S2, the pressure for forming the briquette is 20-30 MPa.

6. The preparation method according to any one of claims 1 to 4, characterized in that, The coal particles have a diameter of 1–10 mm.

7. The preparation method according to claim 6, characterized in that, The coal particles have a diameter of 3–8 mm.

8. The preparation method according to claim 1, characterized in that, The oxidation treatment temperature is 240–255°C.

9. The preparation method according to claim 1, characterized in that, In step S4, the carbonized material is heated to 880-900°C, and then an activator is introduced to perform the activation treatment.