Preparation method for producing spherical activated carbon by using SLEP activation furnace

Abstract

The invention discloses a preparation method for producing spherical activated carbon by using a SLEP activation furnace, and relates to the technical field of activated carbon preparation, the method comprises the following steps: carrying out multi-stage vibration screening treatment on a lignin-based spherical carbon precursor to obtain a large-particle-size spherical carbon raw material and a fine-particle-size spherical carbon raw material; controlling the temperature of the SLEP activation furnace to 850-950 DEG C, carrying out a steam activation reaction on the coarse-particle-size carbonized intermediate for 40-45 hours, and carrying out a steam activation reaction on the fine-particle-size carbonized intermediate for 55-60 hours to obtain a coarse ball carbon activated crude product and a fine ball carbon activated crude product; and sequentially performing multi-stage vibration screening treatment and washing purification treatment on the crude ball carbon activated crude product and the fine ball carbon activated crude product through a second multi-stage vibration screening machine to obtain the finished product spherical activated carbon. According to the method, the quality and uniformity of the product are improved, the stability and efficiency of the production process are improved, and the raw material loss is reduced.

Description

Technical Field

[0001] This application relates to the field of activated carbon preparation technology, and in particular to a method for producing spherical activated carbon using a Sleip furnace. Background Technology

[0002] Spherical activated carbon is widely used in environmental protection, medicine and other fields due to its high specific surface area, regular morphology and excellent adsorption performance. The traditional Sleip activation method for preparing spherical activated carbon has the following significant drawbacks: the raw material spherical carbon has a wide particle size distribution (0.6-2mm), coarse particles require a long activation time, and fine particles are prone to ablation, that is, the particle size difference leads to uneven activation, and the spherical carbon is prone to softening and sticking together during gradient carbonization; at the same time, the volatile matter content of the spherical carbon is as high as 50-55%, which can disrupt the reaction atmosphere in the furnace; in addition, fine-sized spherical carbon (<0.85mm) is prone to leakage in the Sleip furnace. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a method for producing spherical activated carbon using a Sleip furnace. Through the synergistic effect of graded treatment, introduction of auxiliary coal-based columnar carbonization material carriers with specific particle sizes, supplementary carbonization sections using the Sleip furnace, and differentiated activation time control, not only is the quality and uniformity of the product improved, but the stability and efficiency of the production process are also enhanced, and raw material loss is reduced.

[0004] This application provides a method for preparing spherical activated carbon using a Sleip furnace, comprising: To obtain lignin-based spherical carbon precursors, coarse-grained auxiliary coal columnar carbonization material with a diameter of 4.7–4.9 mm, and fine-grained auxiliary coal columnar carbonization material with a diameter of 2.4–2.6 mm; The lignin-based spherical char precursor is subjected to multi-stage vibrating screening using a first multi-stage vibrating screen to obtain coarse-particle-size spherical char raw material and fine-particle-size spherical char raw material. The particle size of the lignin resin balls in the coarse-particle-size spherical char raw material is one of 0.85 to 2 mm, and the particle size of the lignin resin balls in the fine-particle-size spherical char raw material is one of 0.6 to 0.85 mm. The coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain coarse-particle-size spherical carbon mixed feed. The fine-particle-size spherical carbon raw material and the fine-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain fine-particle-size spherical carbon mixed feed. The coarse spherical carbon mixture feed and the fine spherical carbon mixture feed are respectively fed into the Sleip activation furnace. The coarse spherical carbon mixture feed and the fine spherical carbon mixture feed are respectively supplemented carbonized through the supplementary carbonization section of the Sleip activation furnace to obtain a coarse particle size carbonized intermediate corresponding to the coarse spherical carbon mixture feed and a fine particle size carbonized intermediate corresponding to the fine spherical carbon mixture feed. The carbonization temperature of the supplementary carbonization is a gradient carbonization of 185 to 515°C. The temperature of the Sleip activation furnace is controlled to 850-950°C. Steam is used as the activator, and the steam pressure is 0.2-0.3 MPa. The feeding frequency of the Sleip activation furnace is adjusted to carry out a steam activation reaction of 40-45 hours on the coarse-particle-size carbonization intermediate and a steam activation reaction of 55-60 hours on the fine-particle-size carbonization intermediate, so as to obtain a coarse spherical carbon activation crude product corresponding to the coarse-particle-size carbonization intermediate and a fine spherical carbon activation crude product corresponding to the fine-particle-size carbonization intermediate. The coarse activated carbon and fine activated carbon are subjected to multi-stage vibrating sieving by a second multi-stage vibrating sieve to separate the spherical carbon product from the columnar carbonized material, thereby obtaining unpurified spherical activated carbon and columnar activated carbon. The particle size of the unpurified spherical activated carbon is one of 0.6 to 2 mm, and the cylindrical diameter of the columnar activated carbon is one of 4 mm to 2 mm. The columnar activated carbon can be stored as a finished product according to specifications. The unpurified spherical activated carbon was purified by washing with water to obtain the finished spherical activated carbon.

[0005] According to some embodiments of this application, obtaining the lignin-based spherical char precursor includes: Obtain raw material spherical carbon; The raw material spherical carbon was tested for moisture, ash and volatile matter to confirm whether the moisture content of the raw material spherical carbon was below 2% and whether the ash content was below 3%. When the moisture content of the raw material spherical carbon exceeds 2%, the raw material spherical carbon is dried with hot air at 80°C for 110-130 minutes. When the ash content of the raw material spherical carbon exceeds 3%, the raw material spherical carbon is soaked in 5% hydrochloric acid for 110-130 minutes and then washed with water until neutral to obtain a lignin-based spherical carbon precursor.

[0006] According to some embodiments of this application, the first multi-stage vibrating screen includes a primary screen, a secondary screen, and a third screen. The primary screen has a mesh size of 10 mesh, the secondary screen has a mesh size of 20 mesh, and the third screen has a mesh size of 30 mesh. The multi-stage vibrating screening process of the lignin-based spherical char precursor using the first multi-stage vibrating screen to obtain coarse-particle-size spherical char raw material and fine-particle-size spherical char raw material includes: The lignin-based spherical char precursor is subjected to multi-stage vibration sieving through the primary screen, the intermediate screen, and the secondary screen in sequence to obtain coarse-particle-size spherical char raw material and fine-particle-size spherical char raw material.

[0007] According to some embodiments of this application, the step of uniformly mixing the coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal-based columnar carbonization material at a mass ratio of 1:1 to obtain a coarse-particle-size mixed feedstock includes: The coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 using a double-helix conical mixer to obtain coarse spherical carbon mixed feed. Similarly, the process of uniformly mixing the fine-particle-size spherical carbon raw material with the fine-particle-size auxiliary coal columnar carbonization material at a mass ratio of 1:1 to obtain the fine-particle-size spherical carbon mixed feed includes: The fine-particle-size spherical carbon raw material and the fine-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 using the double-helix conical mixer to obtain fine spherical carbon mixed feed.

[0008] According to some embodiments of this application, during uniform mixing, the rotation speed of the double helix conical mixer is 13 to 16 rpm, and the mixing time is 18 to 22 min.

[0009] According to some embodiments of this application, before mixing the coarse-particle-size spherical carbon raw material with the coarse-particle-size auxiliary coal columnar carbonization material and the fine-particle-size spherical carbon raw material with the fine-particle-size auxiliary coal columnar carbonization material respectively, 1% silicone oil emulsion is sprayed onto the coarse-particle-size spherical carbon raw material and the fine-particle-size spherical carbon raw material respectively.

[0010] According to some embodiments of this application, the temperature of the Sleip activation furnace is controlled to 850-950°C, steam is used as the activator, the steam pressure is 0.2-0.3 MPa, and the feeding frequency of the Sleip activation furnace is adjusted to perform a steam activation reaction of 40-45 hours on the coarse-particle-size carbonization intermediate and a steam activation reaction of 55-60 hours on the fine-particle-size carbonization intermediate, to obtain a coarse spherical carbon activation crude product corresponding to the coarse-particle-size carbonization intermediate and a fine spherical carbon activation crude product corresponding to the fine-particle-size carbonization intermediate, including: When the coarse-particle-size carbonized intermediate and the fine-particle-size carbonized intermediate are subjected to steam activation reaction, samples are taken every 30 minutes to detect the iodine adsorption value of the coarse-particle-size carbonized intermediate and the fine-particle-size carbonized intermediate, and to determine whether the iodine adsorption value exceeds the preset range of iodine adsorption. When the iodine adsorption value exceeds the preset range of iodine adsorption, the activation of the corresponding coarse-particle-size carbonized intermediate or the fine-particle-size carbonized intermediate is stopped.

[0011] According to some embodiments of this application, the step of washing and purifying the unpurified spherical activated carbon with water to obtain the finished spherical activated carbon includes: The unpurified spherical activated carbon is rinsed in hot water at 80-90°C for 50-70 minutes to obtain the finished spherical activated carbon. or, The unpurified spherical activated carbon is rinsed in cold water at 20-30°C for 110-130 minutes to obtain the finished spherical activated carbon.

[0012] The beneficial effects of this invention are reflected in obtaining lignin-based spherical carbon precursors, coarse-grained auxiliary coal columnar carbonizing material with a diameter of 4.7–4.9 mm, and fine-grained auxiliary coal columnar carbonizing material with a diameter of 2.4–2.6 mm; the lignin-based spherical carbon precursors are subjected to multi-stage vibrating screening using a first-stage multi-stage vibrating screen to obtain coarse-grained spherical carbon raw materials and fine-grained spherical carbon raw materials. The particle size of the lignin resin balls in the coarse-grained spherical carbon raw materials is one of 0.85–2 mm, and the particle size of the lignin resin balls in the fine-grained spherical carbon raw materials is... The particle size is one of 0.6-0.85 mm; coarse-sized spherical carbon raw material and coarse-sized auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain coarse spherical carbon mixed feed; fine-sized spherical carbon raw material and fine-sized auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain fine spherical carbon mixed feed; the coarse spherical carbon mixed feed and the fine spherical carbon mixed feed are respectively fed into the Sleip activation furnace, and the coarse spherical carbon mixed feed and the fine spherical carbon mixed feed are processed through the supplementary carbonization section of the Sleip activation furnace. Each feedstock undergoes supplementary carbonization to obtain a coarse-particle-size carbonized intermediate corresponding to the coarse spherical carbon mixed feedstock and a fine-particle-size carbonized intermediate corresponding to the fine spherical carbon mixed feedstock. The supplementary carbonization is carried out at a gradient carbonization temperature of 185–515℃. The temperature of the Sleip activation furnace is controlled at 850–950℃, using steam as the activator at a steam pressure of 0.2–0.3 MPa. The feeding frequency of the Sleip activation furnace is adjusted to conduct a 40–45 hour steam activation reaction on the coarse-particle-size carbonized intermediate and a 55-hour steam activation reaction on the fine-particle-size carbonized intermediate. A steam activation reaction lasting -60 hours yields coarse activated spherical carbon products corresponding to coarse-particle-size carbonization intermediates and fine activated spherical carbon products corresponding to fine-particle-size carbonization intermediates. The coarse and fine activated spherical carbon products are then separated by a second-stage multi-stage vibrating screen to separate the spherical carbon products from the columnar activated carbon, resulting in unpurified spherical activated carbon with a particle size ranging from 0.6 to 2 mm. The unpurified spherical activated carbon is then purified by water washing to obtain the finished spherical activated carbon. This application, through this setup, utilizes a graded treatment, the introduction of auxiliary coal-based columnar carbonization material carriers of specific particle sizes, the supplementary carbonization section using a Sleip activation furnace, and differentiated activation time control. This synergistic effect not only improves product quality and uniformity but also enhances the stability and efficiency of the production process while reducing raw material loss.

[0013] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0014] Additional aspects and advantages of this application will become apparent and readily understood in conjunction with the following description of the embodiments, in which: Figure 1 A schematic flowchart of a method for producing spherical activated carbon using a Sleip furnace, provided for embodiments of this application; Figure 2 This is a schematic diagram of the process for obtaining lignin-based spherical char precursors provided in an embodiment of this application; Figure 3 This is a schematic diagram of the process for obtaining coarse-particle-size spherical carbon raw materials and fine-particle-size spherical carbon raw materials according to an embodiment of this application; Figure 4 This is a schematic diagram of the process for obtaining coarse spherical carbon mixed feed provided in an embodiment of this application; Figure 5 This is a schematic diagram of the process for obtaining fine spherical carbon mixed feed provided in an embodiment of this application; Figure 6 A schematic diagram of the process for determining whether the iodine adsorption values ​​of coarse-particle-size carbonization intermediates and fine-particle-size carbonization intermediates are qualified, provided for embodiments of this application; Figure 7 This is a schematic diagram of the process for obtaining finished spherical activated carbon according to an embodiment of this application; Figure 8 This is a schematic diagram of the process for obtaining finished spherical activated carbon according to another embodiment of this application. Detailed Implementation

[0015] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0016] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0017] In the description of this application, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0018] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0019] Spherical activated carbon is widely used in environmental protection, medicine and other fields due to its high specific surface area, regular morphology and excellent adsorption performance. The traditional Sleip activation method for preparing spherical activated carbon has the following significant drawbacks: the raw material spherical carbon has a wide particle size distribution (0.6-2mm), coarse particles require a long activation time, and fine particles are prone to ablation, that is, the particle size difference leads to uneven activation, and the spherical carbon is prone to softening and sticking together during gradient carbonization; at the same time, the volatile matter content of the spherical carbon is as high as 50-55%, which can disrupt the reaction atmosphere in the furnace; in addition, fine-sized spherical carbon (<0.85mm) is prone to leakage in the Sleip furnace.

[0020] To address the aforementioned problems, this application proposes a method for preparing spherical activated carbon using a Sleip furnace. The embodiments of this application will be further described below with reference to the accompanying drawings.

[0021] This application provides a method for preparing spherical activated carbon using a Sleip furnace, such as... Figure 1 As shown, the method includes the following steps: Step S100: Obtain lignin-based spherical carbon precursor, coarse-particle-size auxiliary coal columnar carbonization material with a diameter of 4.7-4.9 mm, and fine-particle-size auxiliary coal columnar carbonization material with a diameter of 2.4-2.6 mm.

[0022] In step S200, the lignin-based spherical carbon precursor is subjected to multi-stage vibrating screening using a first multi-stage vibrating screen to obtain coarse-particle-size spherical carbon raw material and fine-particle-size spherical carbon raw material.

[0023] In this embodiment, the particle size of the lignin resin balls in the coarse-particle-size spherical charcoal raw material is one of 0.85 to 2 mm, and the particle size of the lignin resin balls in the fine-particle-size spherical charcoal raw material is one of 0.6 to 0.85 mm.

[0024] Step S310: The coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain coarse spherical carbon mixed feed.

[0025] Step S320: Fine-particle-size spherical carbon raw material and fine-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain fine-particle-size spherical carbon mixed feed.

[0026] It should be noted that the functions of coarse-particle-size auxiliary coal columnar carbonization material and fine-particle-size auxiliary coal columnar carbonization material are: ① thermal buffer: to prevent local overheating; ② to improve the reaction atmosphere: to improve steam utilization rate.

[0027] It should be noted that the coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to enhance friction and prevent sticking; the fine-particle-size spherical carbon raw material and the fine-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to prevent the fine spherical carbon from getting embedded in the gaps and leaking material.

[0028] For example, coarse-particle-size spherical carbon raw material and coarse-particle-size auxiliary coal columnar carbonization material with a diameter of 4.8 mm are uniformly mixed at a mass ratio of 1:1 to obtain coarse spherical carbon mixed feed; fine-particle-size spherical carbon raw material and fine-particle-size auxiliary coal columnar carbonization material with a diameter of 2.5 mm are uniformly mixed at a mass ratio of 1:1 to obtain fine spherical carbon mixed feed.

[0029] In step S400, the coarse spherical carbon mixed feed and the fine spherical carbon mixed feed are respectively fed into the Sleip activation furnace. The coarse spherical carbon mixed feed and the fine spherical carbon mixed feed are supplemented and carbonized in the supplementary carbonization section of the Sleip activation furnace to obtain a coarse particle size carbonized intermediate corresponding to the coarse spherical carbon mixed feed and a fine particle size carbonized intermediate corresponding to the fine spherical carbon mixed feed.

[0030] In this step, the carbonization temperature for the supplementary carbonization is a gradient carbonization of 185–515°C.

[0031] For example, the temperature control and parameters for supplementary carbonization using the Sleip activation furnace are as follows: temperature 200℃, residence time and conditions: constant temperature for 15 min, physicochemical changes: removal of free water; temperature 300℃, residence time and conditions: maintained until white smoke disappears, physicochemical changes: removal of free water; temperature 500℃, residence time and conditions: constant temperature for 15 min, physicochemical changes: removal of heavy tar, formation of initial pores, and deep carbonization.

[0032] For example, the temperature of the Sleip activation furnace is controlled to 870°C to perform a steam activation reaction of coarse-particle-size carbonization intermediate for 120 minutes and a steam activation reaction of fine-particle-size carbonization intermediate for 140 minutes. The steam flow rate is dynamically adjusted according to the pressure difference inside the Sleip activation furnace to maintain a slightly positive pressure of 0.05 to 0.1 kPa, thereby obtaining coarse spherical carbon activation crude product corresponding to the coarse-particle-size carbonization intermediate and fine spherical carbon activation crude product corresponding to the fine-particle-size carbonization intermediate.

[0033] In step S500, the temperature of the Sleip activation furnace is controlled to 850-950°C. Steam is used as the activator, and the steam pressure is 0.2-0.3 MPa. The feeding frequency of the Sleip activation furnace is adjusted to carry out a steam activation reaction of 40-45 hours for the coarse-particle-size carbonization intermediate and a steam activation reaction of 55-60 hours for the fine-particle-size carbonization intermediate, so as to obtain the coarse spherical carbon activation crude product corresponding to the coarse-particle-size carbonization intermediate and the fine spherical carbon activation crude product corresponding to the fine-particle-size carbonization intermediate.

[0034] In step S600, the crude activated carbon product and the crude activated carbon product of fine activated carbon are subjected to multi-stage vibrating screening by a second multi-stage vibrating screen to separate the spherical carbon product from the columnar carbonized material, thereby obtaining unpurified spherical activated carbon.

[0035] In this step, the particle size of the unpurified spherical activated carbon is one of 0.6 to 2 mm, and the diameter of the columnar activated carbon cylinder is one of 4 mm to 2 mm. The columnar activated carbon can be stored as a finished product according to specifications.

[0036] In one possible implementation, the second multi-stage vibrating screen includes a primary screen and a secondary screen. The primary screen has a 10-mesh aperture, and the secondary screen has a 30-mesh aperture. The lignin-based spherical carbon precursor is sequentially passed through the primary and secondary screens for multi-stage vibrating screening to obtain unpurified spherical activated carbon. The oversize material (>10 mesh) is a columnar auxiliary coal-based columnar carbonization material, which can be recycled for the next batch mixing.

[0037] Step S700: The unpurified spherical activated carbon is washed and purified with water to obtain the finished spherical activated carbon.

[0038] Specifically, the preparation method of producing spherical activated carbon using the Sleip activation furnace provided in this application has the following functions: 1. Processing and differentiated activation: (1) Grading and screening: The raw materials with a wide particle size (0.6-2mm) are accurately divided into two groups: coarse (0.85-2mm) and fine (0.6-0.85mm), allowing for customized processes for different particle size groups; (2) Differentiated activation time: A relatively short activation time (115-125min) is used for the coarse particle size group, and a relatively long activation time (135-145min) is used for the fine particle size group. ① Coarse particles: Although deeper activation is required, the coarse auxiliary coal columnar carbonization material (4.7-4.9mm) in the mixed feed provides excellent support and thermal conductivity, which significantly improves the efficiency of heat and steam transfer to the interior of the coarse spherical carbon particles, enabling them to reach the required activation level in a relatively short time, avoiding the traditional method. The traditional method suffers from the problem of excessively long activation times due to low mass and heat transfer efficiency; ② Fine particles: In traditional methods, fine particles are prone to over-burning (ablation) due to their large surface area and vigorous reaction. In this technology, the fine auxiliary coal columnar carbonization material (2.4-2.6mm) in the mixed feed also improves the bed structure and heat transfer. More importantly, the extended activation time is carried out under milder and more controllable conditions. The presence of the auxiliary coal columnar carbonization material buffers the reaction intensity, allowing fine particles sufficient time to develop the required pore structure (to achieve the target specific surface area and adsorption performance) without being ablated by the instantaneous violent reaction. The extended time is to pursue the uniformity of performance, rather than to compensate for the insufficient reaction rate. This results in the uniform and efficient activation of spherical carbon of different particle sizes, with coarse particles being fully activated without taking too long, and fine particles being fully activated without ablation, ultimately leading to more uniform product performance. 2. Introducing auxiliary coal columnar carbonization material as a physical isolation support: (1) "Spherical carbon-column carbonization material" mixed structure: spherical carbon raw material is mixed with rigid, regularly shaped columnar carbonization material with a particle size significantly larger than spherical carbon at a ratio of 1:1. These columnar carbonization materials form a stable skeleton structure in the bed; (2) Preventing contact: During supplementary carbonization, when spherical carbon (especially lignin-based, with a relatively low softening point) softens due to heat, the surrounding columnar carbonization material physically blocks the direct contact between the softened spherical carbon, greatly reducing the chance of agglomeration; (3) Maintaining porosity: The presence of auxiliary coal columnar carbonization material maintains the porosity of the bed, which is conducive to the escape of volatiles and the uniform distribution of heat; thereby significantly reducing the risk of spherical carbon agglomeration in the key stage of carbonization, ensuring the fluidity of the material and the uniformity of subsequent activation.3. The role of auxiliary coal columnar carbonization material: (1) Buffering of auxiliary coal columnar carbonization material: The auxiliary coal columnar carbonization material itself is a carbonized material with extremely low volatile content. It occupies half of the bed volume and mass, diluting the concentration of volatiles in the spherical carbon. The overall release rate and total peak value of volatiles in the mixed feed are significantly reduced and leveled; (2) Maintaining bed structure: The stable skeleton formed by the auxiliary coal columnar carbonization material can maintain good permeability of the bed even when the spherical carbon softens and releases a large amount of volatiles, so that the volatiles can be discharged smoothly, avoiding local pressure accumulation or airflow turbulence; thereby effectively suppressing the risk of furnace temperature fluctuation, airflow instability, or even local flameout or explosion caused by concentrated release of volatiles, maintaining a stable and uniform reaction atmosphere in the activation furnace, and ensuring activation quality and safe operation of equipment. 4. Matching particle size auxiliary coal columnar carbonization material forms a physical barrier: (1) The role of fine auxiliary coal columnar carbonization material: fine auxiliary coal columnar carbonization material with a particle size of 2.4 to 2.6 mm is specially matched for fine spherical carbon raw material (0.6-0.85 mm). The particle size of these auxiliary coal columnar carbonization materials is much larger than the gap / pore size of the grate (or gas distribution plate) of the activation section of the Sleip furnace; (2) Forming a "filter" layer: in the mixed feed bed, these 2.4-2 mm particles form a physical barrier. The columnar carbonized material particles of 0.6mm overlap each other to form an effective "filter layer" or "barrier layer" at the bottom of the bed; (3) Blocking fine spherical carbon: This physical barrier composed of larger auxiliary particles prevents the fine spherical carbon particles (0.6-0.85mm) from falling directly through the grate gaps; thereby greatly reducing the material leakage loss of fine spherical carbon during the activation process, improving the raw material utilization rate and product yield, and also avoiding material leakage from clogging the furnace bottom or affecting the airflow distribution.

[0039] This application, through this setup, utilizes a combination of graded processing, the introduction of auxiliary coal columnar carbonization carriers with specific particle sizes, the supplementary carbonization section using a Sleip activation furnace, and differentiated activation time control. This not only improves the quality and uniformity of the product but also enhances the stability and efficiency of the production process and reduces raw material loss.

[0040] Understandably, referring to Figure 2 The process of obtaining the lignin-based spherical carbon precursor in step S100 includes, but is not limited to, the following steps: Step S110: Obtain raw material spherical carbon.

[0041] Step S120: The raw material spherical carbon is tested for moisture, ash and volatile matter to confirm whether the moisture content of the raw material spherical carbon is below 2% and the ash content is below 3%. In step S130, when the moisture content of the raw material spherical carbon exceeds 2%, the raw material spherical carbon is dried with hot air at 80°C for 110-130 minutes. When the ash content of the raw material spherical carbon exceeds 3%, the raw material spherical carbon is soaked in 5% hydrochloric acid for 110-130 minutes and then washed with water until neutral to obtain a lignin-based spherical carbon precursor.

[0042] It should be noted that the raw material spherical char can only be confirmed as a lignin-based spherical char precursor if the initial indicators of the raw material spherical char meet the following requirements: moisture ≤ 2%, ash ≤ 3%, and volatile matter between 50% and 55%. If the moisture content of the raw material spherical char is > 2%, it must be dried at 105℃ for 1 hour to prevent steam explosion during carbonization. If the ash content of the raw material spherical char is > 3%, it should be soaked in 5% hydrochloric acid for 1 hour and then washed with water until neutral. If the volatile matter content of the raw material spherical char exceeds the range of 50% to 55%, the activation parameters need to be adjusted.

[0043] It should be noted that the process involves obtaining raw material spherical carbon → testing for moisture, ash, and volatile matter → moisture > 2%: hot air drying at 80℃ for 110-130 min; ash > 3%: soaking in 5% hydrochloric acid for 110-130 min followed by water washing until neutral → obtaining a qualified precursor. The purpose of controlling moisture ≤ 2% is: ① to prevent cracking: during high-temperature carbonization, the instantaneous vaporization of free water can easily cause a sudden increase in internal pressure of the spherical carbon, leading to cracking. Drying pretreatment eliminates this risk; ② to stabilize the reaction atmosphere: avoiding excessive water vapor interfering with the temperature curve and volatile matter release rhythm of subsequent supplementary carbonization. The purpose of controlling ash ≤ 3% is: ① to improve product purity: ash (mainly composed of metal salts) can clog the pores of activated carbon, reducing adsorption performance. Hydrochloric acid treatment dissolves metal oxides (such as K, Ca, and Mg salts), and water washing significantly reduces ash residue; ② to avoid catalytic side effects: metal ash may catalyze carbonization side reactions, leading to pore structure distortion or decreased strength. The purpose of limiting the volatile matter content to 50-55% is as follows: Volatile matter is the main reactant in the carbonization process, and its content directly affects the control of steam consumption during the activation stage. If it exceeds this range, the activation parameters (such as temperature / time) need to be adjusted, otherwise it will lead to insufficient activation or over-burning.

[0044] Reference Figure 3 It is understood that the first multi-stage vibrating screen includes a primary screen, a secondary screen, and a third screen. The primary screen has a mesh size of 10 mesh, the secondary screen has a mesh size of 20 mesh, and the third screen has a mesh size of 30 mesh. Step S200 includes, but is not limited to, the following steps: Step S210: The lignin-based spherical carbon precursor is subjected to multi-stage vibration sieving through a primary sieve, a secondary sieve, and a middle sieve in sequence to obtain coarse-particle-size spherical carbon raw material and fine-particle-size spherical carbon raw material.

[0045] Specifically, the operation table for multi-stage screening by the first multi-stage vibrating screen is shown below: Particle size range of lignin-based spherical carbon precursors Screen assembly Target use Larger than 10 mesh abandoned Large particles can easily clog the grate. 10-20 mesh 20-mesh retention Coarse-grained spherical carbon raw materials 20-30 mesh 30 mesh retention Fine-particle-size spherical carbon raw materials Less than 30 mesh abandoned Overly fine particles are prone to leakage. It should be noted that the 10-mesh sieve has an aperture of 2mm, the 20-mesh sieve has an aperture of 0.85mm, and the 30-mesh sieve has an aperture of 0.6mm.

[0046] It should be noted that the function of step S210 is: (1) Precise particle size grouping: ① Solve the problem of uneven activation caused by a wide range of particle sizes (0.6-2mm) in traditional processes: coarse particles need deep activation but the heat transfer is slow, and fine particles are easily ablated; ② Provide a basis for subsequent differentiated processes (mixing ratio / activation time) and realize independent optimization treatment of coarse and fine particles; (2) Remove extreme particles: ① >10 mesh particles: too large and they are easy to block the grate of the Sleip furnace, which will destroy the airflow distribution; ② <30 mesh particles: too fine and they are easy to leak from the gap of the grate, which will reduce the yield and contaminate the equipment; (3) Improve the uniformity of raw materials: after screening, the particle size difference in each group is reduced, which significantly improves the consistency of the activation reaction.

[0047] Reference Figure 4 It is understood that step S310 includes, but is not limited to, the following steps: Step S311: The coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 using a double-helix conical mixer to obtain coarse spherical carbon mixed feed. Similarly, refer to Figure 5 It is understood that step S320 includes, but is not limited to, the following steps: Step S321: Fine-particle-size spherical carbon raw material and fine-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 using a double-spiral conical mixer to obtain fine spherical carbon mixed feed.

[0048] Understandably, when performing uniform mixing, the rotation speed of the double helix conical mixer is 13 to 16 rpm, and the mixing time is one of 18 to 22 minutes.

[0049] For example, when uniformly mixing coarse-particle-size spherical carbon raw materials with coarse-particle-size auxiliary coal columnar carbonizing materials, and fine-particle-size spherical carbon raw materials with fine-particle-size auxiliary coal columnar carbonizing materials, the rotation speed of the double-spiral conical mixer is 15 rpm, the mixing time is 20 minutes, and the mixing uniformity requirement is: when 5 points are randomly sampled, the spherical carbon content is 48-52%, which meets the standard.

[0050] It should be noted that the spherical char precursor has low mechanical strength and is prone to breakage and fine powder generation during high-speed mixing (leading to material leakage or ablation). The rotation speed of the double-spiral conical mixer is 13-16 rpm to ensure gentle agitation. The mixing time is used to balance efficiency and quality: <18min: insufficient mixing, spherical char and auxiliary materials stratify (weakening the isolation / support effect); >22min: excessively extended cycle, increased energy consumption and possible pre-softening due to frictional heat generation. A strict 1:1 mass ratio is required, and a 48-52% percentage error ensures the spatial distribution consistency of each component (e.g., spherical char is prone to adhesion in areas where auxiliary coal columnar carbonization material is missing).

[0051] It is understandable that before mixing the coarse-particle-size spherical carbon raw material with the coarse-particle-size auxiliary coal columnar carbon material and the fine-particle-size spherical carbon raw material with the fine-particle-size auxiliary coal columnar carbon material in steps S311 and S321 respectively, 1% silicone oil emulsion is sprayed onto the coarse-particle-size spherical carbon raw material and the fine-particle-size spherical carbon raw material respectively.

[0052] It should be noted that the functions of steps S311 and S312 are as follows: (1) To achieve micro-dispersion: ① To prevent agglomeration: During the softening stage of spherical carbon, the columnar auxiliary coal columnar carbonization material (rigid) forms a physical isolation layer between the spherical carbon particles, blocking direct contact (in the traditional process, spherical carbon is easy to melt and agglomerate); ② To prevent leakage: In the fine particle size group, the 2.4-2.6mm columnar carbonization material overlaps at the bottom of the bed to form a "filter", blocking the leakage of 0.6-0.85mm fine spherical carbon from the grate. (2) To optimize the reaction engineering performance: ① Thermal buffer: The thermal conductivity of the auxiliary coal columnar carbonization material (already carbonized) is better than that of spherical carbon, which balances the bed temperature and prevents local overheating; ② Volatile matter dilution: The auxiliary coal columnar carbonization material accounts for 50%, which greatly reduces the volatile matter concentration per unit volume and alleviates the airflow turbulence caused by concentrated release; ③ To improve mass transfer efficiency: The porosity of the mixed bed is increased, which promotes the diffusion of steam into the interior of the spherical carbon and shortens the activation time of coarse particles. (3) Silicone oil emulsion pretreatment (1%): Reduces the surface stickiness of the carbon balls, further enhances the anti-blocking effect, and ensures uniform mixing.

[0053] Reference Figure 6 It is understood that step S500 includes, but is not limited to, the following steps: In step S510, when steam activation reactions are performed on coarse-particle-size carbonized intermediates and fine-particle-size carbonized intermediates respectively, samples are taken every 30 minutes to detect the iodine adsorption values ​​of coarse-particle-size carbonized intermediates and fine-particle-size carbonized intermediates to determine whether the iodine adsorption values ​​exceed the preset range of iodine adsorption. Step S520: When the iodine adsorption value exceeds the preset range of iodine adsorption, the activation of the corresponding coarse-particle-size carbonization intermediate or fine-particle-size carbonization intermediate is stopped.

[0054] In this embodiment, the preset iodine adsorption range for both coarse-particle-size carbonization intermediates and fine-particle-size carbonization intermediates is 1000–1100 mg / g. Iodine adsorption values ​​are measured every 30 minutes to avoid overactivation.

[0055] It should be noted that the functions of steps S510-S520 are: (1) Precise control of the activation endpoint: ① Prevention of overactivation: During the high-temperature steam activation stage (850-950℃), the pore structure of coarse / fine particle carbonized intermediates continues to develop, and the iodine adsorption value directly reflects the degree of micropore development (GB / T12496.8-2015 standard). The preset range of 1000~1100mg / g is the target performance range: >1100mg / g: indicates overactivation, micropores are ablated and expanded into mesopores, resulting in a decrease in strength and yield loss (especially for fine particle size); <1000mg / g: insufficient activation, and the adsorption performance does not meet the standard; ② Real-time intervention: Traditional fixed-time activation is prone to uneven performance due to raw material fluctuations (such as differences in volatile matter). Sampling at 30-minute intervals can dynamically adjust the reaction time to ensure the consistency of performance of each batch of products. (2) Adaptive control of differentiated particle size groups: ① Coarse particle size group: large mass transfer resistance, slow activation rate, and need to monitor whether it reaches the lower limit (1000mg / g); ② Fine particle size group: large specific surface area, violent reaction, and focus on preventing exceeding the upper limit (1100mg / g). For example, if the iodine value of the fine particle size group reaches 1090mg / g at 110min, the activation is terminated immediately to avoid overburning in the following 30min. (3) Process stability assurance: by terminating the reaction beyond the range, the dust generation caused by overactivation is reduced (reducing airflow disturbance in the furnace), and the stability of the micro-positive pressure (0.05~0.1kPa) in the furnace is maintained.

[0056] Reference Figures 7 to 8 It is understood that step S700 includes, but is not limited to, the following steps: Step S710: Rinse the unpurified spherical activated carbon in hot water at 80-90°C for 50-70 minutes to obtain the finished spherical activated carbon. or, In step S720, the unpurified spherical activated carbon is rinsed in cold water at 20-30°C for 110-130 minutes to obtain the finished spherical activated carbon.

[0057] It should be noted that the function of step S610 is to efficiently remove inorganic ash and acid-soluble substances: ① High temperature increases the ion diffusion rate, accelerating the removal of carbonized / activated residual metal oxides (ash) and pretreatment hydrochloric acid immersion residues; ② The time is shortened to 50-70 minutes: High temperature intensifies the thermal motion of water molecules, improving the penetration efficiency through pores and rapidly dissolving soluble salts. Step S610 is applicable in scenarios such as deep cleaning after hydrochloric acid pretreatment when the raw material ash content is >3%, or in applications with stringent ash content requirements (e.g., pharmaceutical carriers).

[0058] It should be noted that the function of step S620 is to gently remove organic residues and protect the pore structure: ① to avoid pore shrinkage caused by high temperature (especially for heat-sensitive materials that have just been activated), and to maintain the specific surface area; ② to fully dissolve the adsorbed tar-like organic matter by soaking for a long time (to replenish the heavy components that were not completely volatilized during carbonization); Step S620 is applicable to scenarios where the raw material has a high volatile content (50-55%), a high risk of tar residue, or the product needs to retain an intact microporous structure.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

[0061] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for preparing spherical activated carbon using a Sleip furnace, characterized in that, include: To obtain lignin-based spherical carbon precursors, coarse-grained auxiliary coal columnar carbonization material with a diameter of 4.7–4.9 mm, and fine-grained auxiliary coal columnar carbonization material with a diameter of 2.4–2.6 mm; The lignin-based spherical char precursor is subjected to multi-stage vibrating screening using a first multi-stage vibrating screen to obtain coarse-particle-size spherical char raw material and fine-particle-size spherical char raw material. The particle size of the lignin resin balls in the coarse-particle-size spherical char raw material is one of 0.85 to 2 mm, and the particle size of the lignin resin balls in the fine-particle-size spherical char raw material is one of 0.6 to 0.85 mm. The coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain coarse-particle-size spherical carbon mixed feed. The fine-particle-size spherical carbon raw material and the fine-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 to obtain fine-particle-size spherical carbon mixed feed. The coarse spherical carbon mixture feed and the fine spherical carbon mixture feed are respectively fed into the Sleip activation furnace. The coarse spherical carbon mixture feed and the fine spherical carbon mixture feed are respectively supplemented carbonized through the supplementary carbonization section of the Sleip activation furnace to obtain a coarse particle size carbonized intermediate corresponding to the coarse spherical carbon mixture feed and a fine particle size carbonized intermediate corresponding to the fine spherical carbon mixture feed. The carbonization temperature of the supplementary carbonization is a gradient carbonization of 185 to 515°C. The temperature of the Sleip activation furnace is controlled to 850-950°C. Steam is used as the activator, and the steam pressure is 0.2-0.3 MPa. The feeding frequency of the Sleip activation furnace is adjusted to carry out a steam activation reaction of 40-45 hours on the coarse-particle-size carbonization intermediate and a steam activation reaction of 55-60 hours on the fine-particle-size carbonization intermediate, so as to obtain a coarse spherical carbon activation crude product corresponding to the coarse-particle-size carbonization intermediate and a fine spherical carbon activation crude product corresponding to the fine-particle-size carbonization intermediate. The coarse activated carbon and fine activated carbon are subjected to multi-stage vibrating sieving by a second multi-stage vibrating sieve to separate the spherical carbon product from the columnar carbonized material, thereby obtaining unpurified spherical activated carbon and columnar activated carbon. The particle size of the unpurified spherical activated carbon is one of 0.6 to 2 mm, and the cylindrical diameter of the columnar activated carbon is one of 4 mm to 2 mm. The columnar activated carbon can be stored as a finished product according to specifications. The unpurified spherical activated carbon was purified by washing with water to obtain the finished spherical activated carbon.

2. The method for preparing spherical activated carbon using a Sleip furnace according to claim 1, characterized in that, The process of obtaining the lignin-based spherical carbon precursor includes: Obtain raw material spherical carbon; The raw material spherical carbon was tested for moisture, ash and volatile matter to confirm whether the moisture content of the raw material spherical carbon was below 2% and whether the ash content was below 3%. When the moisture content of the raw material spherical carbon exceeds 2%, the raw material spherical carbon is dried with hot air at 80°C for 110-130 minutes. When the ash content of the raw material spherical carbon exceeds 3%, the raw material spherical carbon is soaked in 5% hydrochloric acid for 110-130 minutes and then washed with water until neutral to obtain a lignin-based spherical carbon precursor.

3. The method for preparing spherical activated carbon using a Sleip furnace according to claim 1, characterized in that, The first multi-stage vibrating screen includes a primary screen, a secondary screen, and a third screen. The primary screen has a mesh size of 10 mesh, the secondary screen has a mesh size of 20 mesh, and the third screen has a mesh size of 30 mesh. The lignin-based spherical char precursor is subjected to multi-stage vibrating screening using the first multi-stage vibrating screen to obtain coarse-particle-size spherical char raw material and fine-particle-size spherical char raw material, including: The lignin-based spherical char precursor is subjected to multi-stage vibration sieving through the primary screen, the intermediate screen, and the secondary screen in sequence to obtain coarse-particle-size spherical char raw material and fine-particle-size spherical char raw material.

4. The method for preparing spherical activated carbon using a Sleip furnace according to claim 1, characterized in that, The process of uniformly mixing the coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal-based columnar carbonization material at a mass ratio of 1:1 to obtain a coarse-particle-size mixed feedstock includes: The coarse-particle-size spherical carbon raw material and the coarse-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 using a double-helix conical mixer to obtain coarse spherical carbon mixed feed. Similarly, the process of uniformly mixing the fine-particle-size spherical carbon raw material with the fine-particle-size auxiliary coal columnar carbonization material at a mass ratio of 1:1 to obtain the fine-particle-size spherical carbon mixed feed includes: The fine-particle-size spherical carbon raw material and the fine-particle-size auxiliary coal columnar carbonization material are uniformly mixed at a mass ratio of 1:1 using the double-helix conical mixer to obtain fine spherical carbon mixed feed.

5. The method for preparing spherical activated carbon using a Sleip furnace according to claim 4, characterized in that, During the uniform mixing process, the rotation speed of the double helix conical mixer is 13 to 16 rpm, and the mixing time is one of 18 to 22 min.

6. The method for preparing spherical activated carbon using a Sleip furnace according to any one of claims 1 or 4, characterized in that, Before mixing the coarse-particle-size spherical carbon raw material with the coarse-particle-size auxiliary coal columnar carbonization material, and the fine-particle-size spherical carbon raw material with the fine-particle-size auxiliary coal columnar carbonization material, 1% silicone oil emulsion is sprayed onto the coarse-particle-size spherical carbon raw material and the fine-particle-size spherical carbon raw material respectively.

7. The method for preparing spherical activated carbon using a Sleip furnace according to claim 1, characterized in that, The temperature of the Sleip activation furnace is controlled to 850-950°C, steam is used as the activator, steam pressure is 0.2-0.3 MPa, and the feeding frequency of the Sleip activation furnace is adjusted to perform a steam activation reaction of 40-45 hours on the coarse-particle-size carbonization intermediate and a steam activation reaction of 55-60 hours on the fine-particle-size carbonization intermediate, to obtain a coarse spherical carbon activation crude product corresponding to the coarse-particle-size carbonization intermediate and a fine spherical carbon activation crude product corresponding to the fine-particle-size carbonization intermediate, including: When the coarse-particle-size carbonized intermediate and the fine-particle-size carbonized intermediate are subjected to steam activation reaction, samples are taken every 30 minutes to detect the iodine adsorption value of the coarse-particle-size carbonized intermediate and the fine-particle-size carbonized intermediate, and to determine whether the iodine adsorption value exceeds the preset range of iodine adsorption. When the iodine adsorption value exceeds the preset range of iodine adsorption, the activation of the corresponding coarse-particle-size carbonized intermediate or the fine-particle-size carbonized intermediate is stopped.

8. The method for preparing spherical activated carbon using a Sleip furnace according to claim 1, characterized in that, The step of purifying the unpurified spherical activated carbon by washing with water to obtain the finished spherical activated carbon includes: The unpurified spherical activated carbon is rinsed in hot water at 80-90°C for 50-70 minutes to obtain the finished spherical activated carbon. or, The unpurified spherical activated carbon is rinsed in cold water at 20-30°C for 110-130 minutes to obtain the finished spherical activated carbon.

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