Coal-based activated carbon molding, method for preparing the same, and use thereof
By mixing anthracite, coal tar pitch and additives and performing carbonization and activation treatment, the problems of raw material shortage, environmental pollution and high energy consumption in the preparation of coal-based activated carbon are solved, and highly efficient adsorption activated carbon is prepared for water purification.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA ENERGY GRP NINGXIA COAL IND CO LTD
- Filing Date
- 2026-03-12
- Publication Date
- 2026-07-24
AI Technical Summary
The existing coal-based activated carbon preparation process suffers from problems such as difficulty in obtaining raw materials, serious environmental pollution, complex production processes, and high energy consumption.
Anthracite, coal tar pitch and additives are mixed, crushed and screened, then mixed with water and pressed into shape, and then carbonized and activated. Water vapor and/or carbon dioxide are used as activators to form coal-based activated carbon with rich pores and a large specific surface area.
Coal-based activated carbon with abundant pores, high specific surface area, and high wear resistance was prepared, exhibiting extremely strong adsorption properties and suitable for water purification treatment.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of coal materials technology, specifically to a coal-based activated carbon forming process, preparation method, and application. Background Technology
[0002] Coal tar is used as a binder in the production of coal-based activated carbon. Coal tar has a pungent odor and is a black or dark brown, viscous liquid. It is a complex mixture composed almost entirely of aromatic compounds, with tens of thousands of components. During the molding and drying processes, it emits pungent, toxic, and harmful gases, making VOCs treatment extremely difficult.
[0003] Currently, people have used carboxymethyl cellulose, phenolic resin and polyvinyl butyral as binders to form super activated carbon, and have investigated in detail the effects of binder addition amount and binder type on the bulk density, compressive strength and methane adsorption performance of the prepared carbon. Activated carbon products prepared with coal as raw material and cellulose, waste molasses and starch as binders generally have worse performance than activated carbon with coal tar as binder. They have lower strength, poorer stability and significantly increased cost, making it difficult to achieve industrial-scale application. The production of activated carbon with coal tar as binder generally faces the following crises: (1) Raw material crisis: Environmental protection rectification has led to the withdrawal of small coking plants and a sharp reduction in coal tar supply. Due to the technological upgrading of coking plants, the original coal tar composition has changed, the quality fluctuation has increased and the price has soared, posing a great threat to the raw material security. (2) Environmental pressure: The new regulations on VOCs control include toxic volatile substances such as benzo[a]pyrene in key supervision. The existing coal-based activated carbon molding production process uses coal tar as a binder. During storage, kneading, molding and drying, a large amount of VOCs are volatilized and released, which brings huge environmental pressure to activated carbon production enterprises. (3) High production cost: First, the coal tar storage and transportation process requires equipment such as storage tanks, transportation pipelines and pump stations, which requires high investment. Second, coal tar needs to be heated during storage, pipeline transportation and mixing molding to maintain fluidity, and the daily maintenance and repair costs are relatively high. Third, labor costs, electricity and heat energy are required during operation, all of which require cost expenditure. Fourth, in order to prevent the fugitive emission of VOCs, it is necessary to build closed material sheds and plants to collect VOCs gas, and then centrally purify and treat it to meet emission standards. The investment and operation of environmental protection facilities increase production cost expenditure. (4) Difficult to organize production: To maintain the liquid fluidity of coal tar, continuous heating conditions must be met. Equipment and facilities such as stirring pots, conveying pipelines, and storage tanks must have heating or heat preservation functions. Due to cooling or other malfunctions, pipeline blockage often occurs. (5) High energy consumption: Conveying requires electrical energy and heating requires thermal energy, which increases the energy consumption index of the product. Summary of the Invention
[0004] The purpose of this invention is to overcome the problems of difficult-to-obtain raw materials, serious environmental pollution, complex production processes, and high energy consumption in the preparation of coal-based activated carbon, and to provide a method for shaping and preparing coal-based activated carbon, as well as its applications. The coal-based activated carbon prepared according to the method of this invention has abundant pores, a well-developed specific surface area, high wear resistance, and extremely strong adsorption capacity.
[0005] To achieve the above objectives, the present invention provides a method for preparing coal-based activated carbon, the method comprising the following steps: (1) Mix anthracite, coal tar pitch and additives, then crush and screen the resulting mixture to obtain a coal blending mixture; (2) The coal mixture is mixed with water, and then the resulting mixture is pressurized and molded to obtain a molded strip; (3) The molding strip is carbonized and then the resulting product is activated.
[0006] Preferably, in step (1), the mass ratio of the anthracite, the coal tar pitch and the additive is 1:(0.08-1):(0.005-0.1).
[0007] Preferably, the additive is at least one of cellulose ether compounds, starch, and modified starch.
[0008] Preferably, in step (2), the mass ratio of the coal mixture to the water is 1:0.1-0.5.
[0009] Preferably, in step (2), the conditions for pressure molding include: temperature of 0-100℃ and pressure of 0.1-30MPa.
[0010] Preferably, in step (3), the carbonization conditions include: a temperature of 200-750℃ and a time of 20-120min.
[0011] Preferably, in step (3), the activation treatment temperature is 650-1050℃.
[0012] Preferably, in step (3), the activator used in the activation process is water vapor and / or carbon dioxide.
[0013] A second aspect of the present invention provides coal-based activated carbon prepared by the method described above.
[0014] Preferably, the specific surface area of the coal-based activated carbon is ≥1000 m². 2 / g.
[0015] The third aspect of this invention provides the application of the coal-based activated carbon described above in the water purification process.
[0016] According to the preparation method of coal-based activated carbon described in this invention, anthracite and coal tar pitch are used as raw materials, and additives that can form adhesive substances when exposed to water are selected. During the carbonization process, the coal tar pitch undergoes decomposition and thermal condensation reaction to form a semi-coke structure and combine with coal particles, thereby improving the product strength. Specifically, the wear resistance of coal-based activated carbon prepared according to the method described in this invention can reach up to 99%. Detailed Implementation
[0017] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.
[0018] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0019] The method for preparing coal-based activated carbon according to the present invention includes the following steps: (1) Mix anthracite, coal tar pitch and additives, then crush and screen the resulting mixture to obtain a coal blending mixture; (2) The coal mixture is mixed with water, and then the resulting mixture is pressurized and molded to obtain a molded strip; (3) The molding strip is carbonized and then the resulting product is activated.
[0020] In step (1), the pulverization process can be carried out in a grinding mill. The pulverization conditions are such that after pulverizing the mixture, the passing rate when sieved using a 200-mesh sieve is 70-100%, preferably 80-100%.
[0021] In step (1), the mesh size of the sieve used in the sieving process can be 150-250 mesh, preferably 180-220 mesh, specifically, for example, 180 mesh, 190 mesh, 200 mesh, 210 mesh or 220 mesh.
[0022] In step (1), the mass ratio of the anthracite, the coal tar pitch, and the additive can be 1:(0.08-1):(0.005-0.1), preferably 1:(0.1-0.5):(0.01-0.05). In a specific embodiment, the anthracite is purchased from Ningxia Coal Industry Co., Ltd. of China Energy Investment Corporation, with an ash content of 3%. The coal tar pitch can be selected from various conventional coal tar pitch varieties in the art, conforming to the national standard GB / T 2290-2012.
[0023] In the method described in this invention, the additive may be at least one selected from cellulose ether compounds, starch, and modified starch. In the most preferred embodiment, the additive is starch.
[0024] In step (2), the mass ratio of the coal mixture to the water can be 1:0.1-0.5, preferably 1:0.2-0.4.
[0025] In step (2), the pressure molding process can be carried out in a hydraulic press. The conditions for pressure molding may include: a temperature of 0-100°C and a pressure of 0.1-30 MPa. Preferably, the conditions for cold pressing include: a temperature of 25-40°C and a pressure of 10-15 MPa.
[0026] In step (3), the carbonization conditions may include a temperature of 200-750℃ and a time of 20-120 min. Preferably, the carbonization conditions include a temperature of 300-650℃ and a time of 30-100 min. The carbonization process can be carried out in a carbonization furnace.
[0027] In step (3), the activation temperature can be 650-1050℃, preferably 900-1000℃. The activation process can be carried out in an activation furnace.
[0028] In step (3), the activator used in the activation process can be water vapor and / or carbon dioxide. In the most preferred embodiment, the activator used in the activation process is water vapor.
[0029] This invention also provides coal-based activated carbon prepared by the above method. This coal-based activated carbon has abundant pores and a well-developed specific surface area, exhibiting both high wear resistance and extremely strong adsorption capacity. Preferably, the specific surface area of the coal-based activated carbon is ≥1000 m². 2 / g, preferably 1000-1500m 2 / g.
[0030] The present invention also provides the application of the coal-based activated carbon in the water purification process.
[0031] The following examples further illustrate the coal-based activated carbon forming, preparation method, and application of the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.
[0032] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.
[0033] In the following examples and comparative examples, the relevant technical indicators of coal-based activated carbon were tested according to the following methods: Specific surface area and pore size analysis: The specific surface area and pore size of the samples were analyzed using a physical adsorption analyzer. The tests were conducted according to standard GB / T 7702.20-2008.
[0034] Abrasion resistance test: The test shall be conducted in accordance with the standard GB / T7702.3.
[0035] Iodine adsorption value determination: The determination shall be carried out in accordance with the standard GB / T7702.7.
[0036] Carbon tetrachloride adsorption rate determination: The determination was carried out in accordance with standard GB / T7702.13.
[0037] Example 1 (1) Anthracite (purchased from Ningxia Coal Industry Co., Ltd. of China Energy Group, with ash content of 3%, the same below), coal tar pitch and starch are mixed in a mass ratio of 1:0.2:0.01. The resulting mixture is then added to a grinding mill for crushing. The crushed material is then sieved through a 200-mesh screen with a sieve rate of 85% to obtain a coal blend mixture.
[0038] (2) The coal mixture obtained in step (1) and water are added to the mixing pot at a mass ratio of 1:0.2 and stirred for 10 minutes at a speed of 60 r / min. The resulting mixture is then sent to a hydraulic press for pressure molding. The pressure molding conditions include a temperature of 30℃ and a pressure of 10 MPa to obtain a molded strip.
[0039] (3) Place the shaped strip obtained in step (2) in a carbonization furnace, start heating from 350°C, heat to 650°C in 20 minutes, and perform carbonization treatment for 20 minutes. Then place the obtained product in an activation furnace and perform activation treatment in the presence of water vapor. The activation treatment conditions include: temperature of 900°C and time of 120 minutes to obtain coal-based activated carbon A1.
[0040] Example 2 (1) Mix anthracite, coal tar pitch and starch in a mass ratio of 1:0.5:0.02, then add the mixture to a grinding mill for crushing, and then sieve the crushed material through a 200-mesh screen with a sieve rate of 87% to obtain a coal blend mixture.
[0041] (2) The coal mixture obtained in step (1) and water are added to the mixing pot at a mass ratio of 1:0.3 and stirred for 10 minutes at a speed of 60 r / min. The resulting mixture is then sent to a hydraulic press for pressure molding. The pressure molding conditions include a temperature of 40℃ and a pressure of 15 MPa to obtain a molded strip.
[0042] (3) Place the shaped strip obtained in step (2) in a carbonization furnace, start heating from 350°C, heat to 700°C in 20 minutes, and perform carbonization treatment for 20 minutes. Then place the obtained product in an activation furnace and perform activation treatment in the presence of water vapor. The activation treatment conditions include: temperature of 900°C and time of 120 minutes to obtain coal-based activated carbon A2.
[0043] Example 3 (1) Mix anthracite, coal tar pitch and starch in a mass ratio of 1:0.2:0.05, then add the mixture to a grinding mill for crushing, and then sieve the crushed material through a 200-mesh screen with a sieve rate of 83% to obtain a coal blend mixture.
[0044] (2) Add the coal mixture obtained in step (1) and water to a mixing pot at a mass ratio of 1:0.5 and stir for 10 minutes at a speed of 60 r / min. Then, send the resulting mixture to a hydraulic press for pressure molding. The pressure molding conditions include a temperature of 40℃ and a pressure of 20 MPa to obtain a molded strip.
[0045] (3) Place the shaped strip obtained in step (2) in a carbonization furnace, start heating from 350°C, heat to 750°C in 20 minutes, and perform carbonization treatment for 20 minutes. Then place the obtained product in an activation furnace and perform activation treatment in the presence of water vapor. The activation treatment conditions include: temperature of 900°C and time of 120 minutes to obtain coal-based activated carbon A3.
[0046] Example 4 Coal-based activated carbon was prepared according to the method of Example 1, except that in step (1), the mass ratio of anthracite, coal tar pitch and starch was adjusted to 1:0.08:0.02 to obtain coal-based activated carbon A4.
[0047] Example 5 Coal-based activated carbon was prepared according to the method of Example 1, except that in step (1), the mass ratio of anthracite, coal tar pitch and starch was adjusted to 1:0.2:0.005 to obtain coal-based activated carbon A5.
[0048] Example 6 Coal-based activated carbon was prepared according to the method of Example 1, except that in step (2), the mass ratio of coal mixture and water was adjusted to 1:0.6 to obtain coal-based activated carbon A6.
[0049] Example 7 Coal-based activated carbon was prepared according to the method of Example 1, except that in step (3), the carbonization temperature was adjusted to start from 350°C, rise to 650°C in 20 minutes, and then be subjected to constant temperature carbonization at 650°C for 40 minutes to obtain coal-based activated carbon A7.
[0050] Example 8 Coal-based activated carbon was prepared according to the method of Example 1, except that in step (3), the activation temperature was adjusted to 950°C and the time was 120 min to obtain coal-based activated carbon A8.
[0051] Example 9 Coal-based activated carbon was prepared according to the method of Example 1, except that in step (3), water vapor was replaced with carbon dioxide to obtain coal-based activated carbon A9.
[0052] Comparative Example 1 Coal-based activated carbon was prepared according to the method of Example 1, except that coal pitch was not added in step (1), and coal-based activated carbon D1 was obtained.
[0053] The performance parameters of the coal-based activated carbon prepared in the above embodiments and comparative examples are shown in Table 1 below.
[0054] Table 1
[0055] As can be seen from the results in Table 1, the coal-based activated carbon prepared according to the method of the present invention has both high wear resistance and extremely strong adsorption capacity.
[0056] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.
Claims
1. A method for preparing coal-based activated carbon, characterized in that, The method includes the following steps: (1) Mix anthracite, coal tar pitch and additives, then crush and screen the resulting mixture to obtain a coal blending mixture; (2) The coal mixture is mixed with water, and then the resulting mixture is pressurized and molded to obtain a molded strip; (3) The molding strip is carbonized and then the resulting product is activated.
2. The method according to claim 1, characterized in that, In step (1), the mass ratio of the anthracite, the coal tar pitch and the additive is 1:(0.08-1):(0.005-0.1).
3. The method according to claim 1 or 2, characterized in that, The additive is at least one of cellulose ether compounds, starch, and modified starch.
4. The method according to claim 1, characterized in that, In step (2), the mass ratio of the coal mixture to the water is 1:0.1-0.
5.
5. The method according to claim 1 or 4, characterized in that, In step (2), the conditions for pressure molding include: temperature of 0-100℃ and pressure of 0.1-30MPa.
6. The method according to claim 1, characterized in that, In step (3), the carbonization conditions include a temperature of 200-750℃ and a time of 20-120min.
7. The method according to claim 1 or 6, characterized in that, In step (3), the activation treatment temperature is 650-1050℃.
8. The method according to claim 1, 6, or 7, characterized in that, In step (3), the activator used in the activation process is water vapor and / or carbon dioxide.
9. Coal-based activated carbon prepared by the method according to any one of claims 1-8; Preferably, the specific surface area of the coal-based activated carbon is ≥1000 m². 2 / g.
10. The application of the coal-based activated carbon according to claim 9 in the water purification process.