Coking coal additive, method for preparing the same, coking coal composition, and coking method
By leveraging the synergistic effect of modified clay, organic binders, and pyrolysis catalysts in coking coal additives, the problem of poor binding properties of low-rank coal during coking is solved, improving the hot properties and utilization rate of coke and meeting the requirements of blast furnace ironmaking.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XINJIANG TIANCHI ENERGY SOURCES CO LTD
- Filing Date
- 2026-03-12
- Publication Date
- 2026-06-05
AI Technical Summary
Low-rank coal has high volatile matter, poor caking properties, and weak coking properties during the coking process, which leads to a decline in coke quality and makes it unable to meet the requirements of blast furnace ironmaking. Furthermore, traditional additives have limited effect in improving this.
Coking coal additives, including modified clay, organic binders, oxidants and pyrolysis catalysts, are used to improve the utilization rate of low-rank coal and the hot properties of coke through a specific mass ratio synergistic effect.
By increasing the proportion of low-rank coal, the resulting coke has high hot strength and low reactivity, meeting the requirements of blast furnace ironmaking, reducing dependence on high-quality coking coal, and saving costs.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This application relates to the field of coal chemical technology, and in particular to a coking coal additive and its preparation method, a coking coal composition, and a coking method. Background Technology
[0002] Coking coal is the cornerstone of the iron and steel metallurgical industry. Its core application is the production of metallurgical coke through high-temperature carbonization (coking), which is then used in blast furnace ironmaking. With the increasing scarcity of high-quality coking coal resources, it is necessary to effectively utilize abundant low-rank coals, such as lignite and long-flame coal, to replace some of the high-quality coking coal. Low-rank coal has disadvantages such as high volatile matter, poor caking properties, and weak coking ability. Blending it into coking coal can easily lead to a decline in coke quality and poor thermal properties, failing to meet the requirements of blast furnace ironmaking. Therefore, the current blending ratio of low-rank coal is low, usually not exceeding 10%, resulting in low utilization. Summary of the Invention
[0003] Therefore, it is necessary to provide a coking coal additive and its preparation method, a coking coal composition, and a coking method that take into account both the utilization rate of low-rank coal and the hot properties of coke.
[0004] One aspect of this application provides a coking coal additive, which, by weight, comprises the following raw material components: 20 to 30 parts of modified clay, 10 to 15 parts of organic binder, 5 to 10 parts of oxidant, 3 to 8 parts of pyrolysis catalyst, and 30 to 50 parts of first solvent.
[0005] The modified clay mentioned above includes silane coupling agent modified montmorillonite; the organic binder mentioned above includes coal tar heavy components and polyvinyl alcohol.
[0006] The above-mentioned coking coal additives, when used in coking coal blending, can increase the proportion of low-rank coal in the raw coal, resulting in better coke performance, improving the utilization rate of low-rank coal, reducing the dependence of coking on high-quality coking coal, and saving costs. Among them, silane coupling agent modified montmorillonite can serve as a nanoframework, effectively filling the pores of raw coal particles, increasing the density of raw coal, and inhibiting coke matrix shrinkage and cracking at high temperatures, thus improving the compactness of coke; polyvinyl alcohol in the organic binder provides excellent room-temperature adhesion and formability, while coal tar heavy components can provide a rich and stable carbonaceous liquid phase during the coking stage. The two work synergistically to enhance the adhesion between raw coal particles, promote the formation of a high-strength coke structure, and obtain coke with high hot strength; oxidant can moderately oxidize low-rank coal, reduce its volatile matter release rate, and reduce coke cracks; pyrolysis catalyst can promote the pyrolysis and condensation reaction of raw coal particles, further improving the strength of coke; through the interaction of modified clay, organic binder, oxidant, and pyrolysis catalyst in a specific mass ratio, the synergistic effect is enhanced, and the resulting coke has high hot strength and low reactivity under the premise of increasing the proportion of low-rank coal, thus improving the hot properties and other quality of coke, making it meet the requirements of blast furnace ironmaking.
[0007] In some embodiments, the average particle size of the silane coupling agent modified montmorillonite is 10µm to 50µm.
[0008] In some embodiments, the coal tar heavy components, by mass percentage, include 40%–60% bitumen, 10%–25% anthracene compounds, 8%–25% phenanthrene compounds, and 5%–10% pyrene compounds; and / or,
[0009] The boiling point of the heavy components of coal tar is 350℃~450℃; and / or,
[0010] The degree of polymerization of polyvinyl alcohol is 1700~1800; and / or,
[0011] The mass ratio of coal tar heavy components to polyvinyl alcohol is 3:1 to 5:1.
[0012] In some embodiments, the oxidant includes at least one of potassium permanganate and potassium dichromate; and / or, the pyrolysis catalyst includes an iron-based catalyst.
[0013] A second aspect of this application provides a method for preparing coking coal additives as described in the first aspect, comprising the following steps:
[0014] Modified clay, organic binder, oxidant and pyrolysis catalyst are mixed in the first solvent according to the mass ratio of the raw material components to obtain coking coal additive.
[0015] In some embodiments, the method for preparing modified clay includes the following steps:
[0016] Montmorillonite was reacted with a silane coupling agent in a second solvent under heating conditions to obtain a mixture;
[0017] Solid-liquid separation of the mixture;
[0018] The solid phase after solid-liquid separation is dried to obtain silane coupling agent modified montmorillonite;
[0019] The silane coupling agent has a mass fraction of 3% to 5% in the second solvent; the mass ratio of montmorillonite to the total mass of the silane coupling agent and the second solvent is 1:5 to 8; the heating temperature is 60℃ to 80℃; the heating time is 2h to 3h; and the drying temperature is 80℃ to 100℃.
[0020] In some embodiments, the method for preparing the organic binder includes the following steps:
[0021] The light components of coal tar are removed by heating, and the heavy components of coal tar are obtained.
[0022] Polyvinyl alcohol is dissolved in a third solvent under heating conditions to obtain a polyvinyl alcohol solution;
[0023] The heavy components of coal tar were mixed with a polyvinyl alcohol solution to obtain an organic binder;
[0024] The mass ratio of coal tar heavy components to polyvinyl alcohol solution is 3~5:1; the mass fraction of polyvinyl alcohol in polyvinyl alcohol solution is 10%~15%.
[0025] A third aspect of this application provides a coking coal composition comprising raw coal and a coking coal additive of the first aspect, wherein the raw coal comprises coking coal and low-rank coal.
[0026] In some embodiments, the mass ratio of the coking coal additive to the raw coal is 1% to 3%; and / or,
[0027] In the raw coal, the mass content of low-rank coal is 15% to 25%; and / or,
[0028] Low-rank coal includes at least one of lignite and long-flame coal; and / or,
[0029] Coking coal includes at least one of coking coal, fat coal, and gas coal; optionally, the raw coal includes 30% to 40% coking coal, 20% to 25% fat coal, 15% to 20% gas coal, and 15% to 25% low-rank coal.
[0030] A fourth aspect of this application provides a coking method, comprising the following steps:
[0031] S1: Mix coking coal with low-rank coal to form raw coal;
[0032] S2: Add the coking coal additive from the first aspect to the raw coal, mix and make coal cake;
[0033] S3: Coking the coal briquettes to obtain coke;
[0034] The mixing temperature is 30℃~40℃; the density of the coal cake is 1.05t / m³. 3 ~1.15t / m 3 The coking time is 18h~24h; the coking temperature is 900℃~1000℃; the coking process adopts a segmented heating method, with the temperature increased to 400℃~450℃ at a heating rate of 100℃ / min~150℃ / min from 0h to 6h, to 600℃~700℃ at a heating rate of 80℃ / min~120℃ / min from 6h to 12h, and to 900℃~1000℃ at a heating rate of 50℃ / min~80℃ / min from 12h to 20h. Detailed Implementation
[0035] To facilitate understanding of this application, a more complete description of the application will be provided below with reference to relevant embodiments. Preferred embodiments of the application are shown herein. However, the application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.
[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0037] In the iron and steel metallurgical industry, coke is a crucial raw material for blast furnace ironmaking. Its thermal properties, such as thermal strength and reactivity, directly affect the smooth operation and production efficiency of the blast furnace. With the increasing scarcity of high-quality coking coal resources, how to effectively utilize abundant low-rank coals, such as lignite and long-flame coal, to replace some of the high-quality coking coal while ensuring that the coke possesses good thermal properties has become an urgent problem to be solved in the current coal chemical industry.
[0038] Low-rank coal is characterized by high volatile matter, poor caking properties, and weak coking ability. Directly blending it in large quantities into coking coal will result in a loose coke structure, reduced strength, and a significant decline in hot-state properties, making the produced coke unsuitable for blast furnace ironmaking. To improve the coking performance of low-rank coal, various additives are typically added. However, traditional additives suffer from limitations such as single function, limited improvement effects, and high cost. For example, some additives can only improve the caking properties of coal to a certain extent, but their effect on reducing coke reactivity and improving hot-state strength is not significant.
[0039] Based on this, one aspect of this application provides a coking coal additive, which, by mass, comprises the following raw material components: 20 to 30 parts of modified clay, 10 to 15 parts of organic binder, 5 to 10 parts of oxidant, 3 to 8 parts of pyrolysis catalyst, and 30 to 50 parts of first solvent.
[0040] Among them, modified clay includes silane coupling agent modified montmorillonite;
[0041] Organic binders include coal tar heavy components and polyvinyl alcohol.
[0042] The above-mentioned coking coal additives, when used in coking coal blending, can increase the proportion of low-rank coal in the raw coal, resulting in better coke performance, improving the utilization rate of low-rank coal, reducing the dependence of coking on high-quality coking coal, and saving costs. Among them, silane coupling agent modified montmorillonite can serve as a nanoframework, effectively filling the pores of raw coal particles, increasing the density of raw coal, and inhibiting coke matrix shrinkage and cracking at high temperatures, thus improving the compactness of coke; polyvinyl alcohol in the organic binder provides excellent room-temperature adhesion and formability, while coal tar heavy components can provide a rich and stable carbonaceous liquid phase during the coking stage. The two work synergistically to enhance the adhesion between raw coal particles, promote the formation of a high-strength coke structure, and obtain coke with high hot strength; oxidant can moderately oxidize low-rank coal, reduce its volatile matter release rate, and reduce coke cracks; pyrolysis catalyst can promote the pyrolysis and condensation reaction of raw coal particles, further improving the strength of coke; through the interaction of modified clay, organic binder, oxidant, and pyrolysis catalyst in a specific mass ratio, the synergistic effect is enhanced, and the resulting coke has high hot strength and low reactivity under the premise of increasing the proportion of low-rank coal, thus improving the hot properties and other quality of coke, making it meet the requirements of blast furnace ironmaking.
[0043] The aforementioned coking coal additives are low in cost and easy to produce industrially.
[0044] As an example, the modified clay can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, or 30 parts, or it can be within the range formed by any two of the above point values as endpoints. Further, the mass fraction of the modified clay is 25 to 30 parts.
[0045] As an example, the organic binder can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, and 15 parts, or it can be within the range formed by any two of the above points as endpoints. Further, the mass parts of the organic binder are 11 to 14 parts.
[0046] As an example, the oxidant can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, and 10 parts, or it can be within the range formed by any two of the above point values as endpoints. Further, the mass parts of the oxidant are 6 to 9 parts.
[0047] As an example, the pyrolysis catalyst can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, and 8 parts, or it can be within the range formed by any two of the above point values as endpoints. Further, the mass parts of the pyrolysis catalyst are 4 to 7 parts.
[0048] As an example, the first solvent can be 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 parts, 49 parts, or 50 parts, or it can be within a range formed by any two of the above point values as endpoints. Further, the mass fraction of the solvent is 35 to 45 parts.
[0049] In some embodiments, the first solvent includes at least one of water and ethanol.
[0050] In some embodiments, the particle size of the silane coupling agent modified montmorillonite is ≤50µm.
[0051] In some embodiments, the average particle size of the silane coupling agent modified montmorillonite is 10µm to 50µm.
[0052] As an example, the particle size of silane coupling agent modified montmorillonite can be 1µm, 5µm, 10µm, 15µm, 20µm, 25µm, 30µm, 35µm, 40µm, 45µm, or 50µm, or within the range defined by any two of the above values as endpoints. Further, the particle size of silane coupling agent modified montmorillonite is 15µm to 35µm. Coking coal additives prepared within this particle size range can be uniformly dispersed and filled into the micropores and gaps of raw coal particles during coal blending, reducing structural defects and improving the heating uniformity of raw coal, further increasing the hot strength of coke and reducing its reactivity.
[0053] In some embodiments, the organic binder is a mixture of coal tar heavy components and polyvinyl alcohol.
[0054] In some embodiments, the coal tar heavy components, by mass percentage, include 40% to 60% bitumen, 10% to 25% anthracene compounds, 8% to 25% phenanthrene compounds, and 5% to 10% pyrene compounds.
[0055] In some embodiments, the boiling point of the coal tar heavy components is 350°C to 450°C.
[0056] In some embodiments, the degree of polymerization of polyvinyl alcohol is 1700-1800.
[0057] In some embodiments, the mass ratio of coal tar heavy components to polyvinyl alcohol is 3:1 to 5:1.
[0058] In some embodiments, the oxidant includes at least one of potassium permanganate and potassium dichromate.
[0059] In some embodiments, the particle size of the oxidant is ≤100 mesh.
[0060] In some of these embodiments, the pyrolysis catalyst includes an iron-based catalyst.
[0061] Furthermore, the iron-based catalyst includes at least one of ferric nitrate and ferric chloride.
[0062] A second aspect of this application provides a method for preparing coking coal additives as described in the first aspect, comprising the following steps:
[0063] Modified clay, organic binder, oxidant and pyrolysis catalyst are mixed in the first solvent according to the mass ratio of the raw material components to obtain coking coal additive.
[0064] In some embodiments, the method for preparing modified clay includes the following steps:
[0065] Montmorillonite was reacted with a silane coupling agent in a second solvent under heating conditions to obtain a mixture;
[0066] Solid-liquid separation of the mixture;
[0067] The solid phase after solid-liquid separation is dried to obtain silane coupling agent modified montmorillonite.
[0068] Furthermore, the second solvent is water.
[0069] In some embodiments, the silane coupling agent has a mass fraction of 3% to 5% in the second solvent.
[0070] As an example, the mass fraction of the silane coupling agent in the second solvent can be 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, or 5%, or within a range defined by any two of the above values as endpoints. The preferred mass fraction of the silane coupling agent is 3.5% to 4.5%. Coking coal additives prepared within this range can further reduce the proportion of low-rank coal and produce coke with better hot properties.
[0071] In some embodiments, the mass ratio of montmorillonite to the total mass of the silane coupling agent and the second solvent is 1:5 to 8.
[0072] As an example, the mass ratio of montmorillonite to silane coupling agent solution can be 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, or 1:8, or it can be within the range defined by any two of the above values. The preferred mass ratio of montmorillonite to silane coupling agent solution is 1:6 to 1:7.
[0073] Furthermore, in the preparation method of silane coupling agent modified montmorillonite, montmorillonite is mixed with an aqueous solution of silane coupling agent with a mass fraction of 3%~5% at a mass ratio of 1:5~8 and reacted.
[0074] In some embodiments, the heating temperature for reacting montmorillonite with the silane coupling agent solution under heating conditions is 60°C to 80°C.
[0075] In some embodiments, the montmorillonite and silane coupling agent solution are heated for 2 to 3 hours under heating conditions.
[0076] In some embodiments, the drying temperature during the preparation of silane coupling agent modified montmorillonite is 80°C to 100°C.
[0077] In some embodiments, the method for preparing the organic binder includes the following steps:
[0078] The light components of coal tar are removed by heating, and the heavy components of coal tar are obtained.
[0079] Polyvinyl alcohol is dissolved in a third solvent under heating conditions to obtain a polyvinyl alcohol solution;
[0080] The heavy components of coal tar are mixed with a polyvinyl alcohol solution to obtain an organic binder.
[0081] In some embodiments, the preparation method of the heavy coal tar components is as follows:
[0082] Heavy coal tar components can be obtained by removing light components from medium-temperature coal tar with a softening point of 70℃~90℃ at a temperature of 150℃~180℃.
[0083] Furthermore, water is used as the third solvent.
[0084] In some embodiments, the mass ratio of the coal tar heavy components to the polyvinyl alcohol solution is 3-5:1. The polyvinyl alcohol is dissolved in a third solvent under heating conditions to form a polyvinyl alcohol solution.
[0085] As an example, the mass ratio of coal tar heavy components to polyvinyl alcohol solution can be 3:1, 3.5:1, 4:1, 4.5:1 or 5:1, or it can be within the range formed by any two of the above point values as endpoints.
[0086] In some embodiments, the mass fraction of polyvinyl alcohol in the polyvinyl alcohol solution is 10% to 15%.
[0087] As an example, the mass fraction of polyvinyl alcohol in the polyvinyl alcohol solution can be 10%, 11%, 12%, 13%, 14%, or 15%, or within a range defined by any two of the above values. The preferred mass fraction of polyvinyl alcohol in the polyvinyl alcohol solution is 14% to 15%. Coking coal additives prepared within this range exhibit moderate viscosity and good rheological properties, improving the compositional uniformity of the coking coal additive and the quality of the coal cake, further enhancing the hot strength of the coke, allowing for a further reduction in the proportion of low-rank coal, and resulting in coke with better hot properties.
[0088] In some embodiments, the mass ratio of coal tar heavy components to polyvinyl alcohol solution in the organic binder is 3-5:1, and the mass fraction of polyvinyl alcohol in the polyvinyl alcohol solution is 10%-15%.
[0089] Furthermore, polyvinyl alcohol is dissolved in hot water at 80℃~90℃ to form a polyvinyl alcohol aqueous solution with a mass fraction of 10%~15%, and then compounded with coal tar heavy components to form an organic binder.
[0090] In some embodiments, the iron-based catalyst is prepared as an aqueous solution with a mass fraction of 5% to 10% when used.
[0091] In some embodiments, the modified clay is passed through a 200-mesh sieve before blending to improve the particle size uniformity of the modified clay.
[0092] In some embodiments, modified clay, organic binder, oxidant, and pyrolysis catalyst are added sequentially to the first solvent, and the mixture is stirred and mixed at 150 r / min to 250 r / min at 50°C to 70°C for 1 h to 2 h using an anchor stirrer.
[0093] Furthermore, to ensure reaction uniformity, ultrasonic-assisted dispersion can be used for 15-30 minutes during stirring. This improves reaction uniformity and promotes the final obtaining of a uniform and stable suspension, which is the coking coal additive.
[0094] A third aspect of this application provides a coking coal composition comprising raw coal and a coking coal additive of the first aspect, wherein the raw coal comprises coking coal and low-rank coal.
[0095] Understandably, low-rank coal refers to coal with a lower degree of coalification, such as lignite and long-flame coal. Coking coal refers to coal with good caking and coking properties, such as coking coal, bituminous coal, and gas coal.
[0096] In some embodiments, the mass ratio of the coking coal additive to the raw coal is 1% to 3%.
[0097] In some embodiments, the mass content of low-rank coal in the raw coal is 15% to 25%. Currently, the proportion of low-rank coal is low, usually not exceeding 10%, while this application increases the proportion of low-rank coal to 15% to 25%, which not only improves the utilization rate of low-rank coal, but also produces coke with excellent hot properties, achieving unexpected results.
[0098] In some of these embodiments, the low-rank coal includes at least one of lignite and long-flame coal.
[0099] Furthermore, the moisture content of low-rank coal is 15% to 25% by mass.
[0100] Furthermore, the ash content of low-rank coal is 8% to 12% by mass.
[0101] In some embodiments, the coking coal includes at least one of coking coal, bituminous coal, and gas coal.
[0102] In some embodiments, the volatile matter content of the coking coal is 18% to 25% by mass.
[0103] In some embodiments, the maximum thickness Y of the plastic layer of coking coal is 18 mm to 25 mm.
[0104] In some embodiments, the maximum thickness Y of the plastic layer of the coking coal is 25 mm to 30 mm.
[0105] In some of these embodiments, the caking index G of the coking coal is 85 to 95.
[0106] In some embodiments, the volatile matter content of the gas coal is 30% to 37% by mass.
[0107] In some embodiments, the raw coal includes 30% to 40% coking coal, 20% to 25% fat coal, 15% to 20% gas coal, and 15% to 25% low-rank coal.
[0108] A fourth aspect of this application provides a coking method, comprising the following steps:
[0109] S1: Mix coking coal with low-rank coal to form raw coal;
[0110] S2: Add the coking coal additive from the first aspect to the raw coal, mix and make coal cake;
[0111] S3: Coking the coal cake to obtain coke.
[0112] In some embodiments, the mixing temperature in S1 is 30°C to 40°C.
[0113] In some embodiments, in S1, the raw coal is crushed using a crushing system combining a hammer crusher and a vibrating screen, so that more than 90% of the coal particles are smaller than or equal to 3 mm.
[0114] In some embodiments, the mixing temperature in step S2 is 30°C to 40°C. Maintaining the internal temperature of the coal mixer at 30°C to 40°C during the mixing process prevents the volatilization of organic components in the coking coal powder additives.
[0115] In some embodiments, the mixing time in S2 is 10 min to 15 min.
[0116] In some embodiments, in S2, the density of the coal cake is 1.05 t / m³. 3 ~1.15t / m 3 .
[0117] In some embodiments, in S2, the coal cake is made by the following tamping method: the mixed raw coal is transported to a tamping machine, and tamping is performed by hydraulic drive with a tamping pressure of 20MPa~30MPa and a tamping time of 3 min~5 min; during the tamping process, the height of the coal cake is monitored in real time by a laser rangefinder to ensure that the density of the coal cake reaches 1.05-1.15t / m³.
[0118] In some embodiments, in step S2, nano-silica is also added to the raw coal, and the mass ratio of nano-silica to raw coal is 0.5% to 1%.
[0119] In some embodiments, the coking time in S3 is 18h to 24h.
[0120] In some embodiments, in S3, the coking temperature is 900°C to 1000°C;
[0121] In some embodiments, the coking process employs a staged heating method, with the temperature increased to 400℃~450℃ at a heating rate of 100℃ / min~150℃ / min from 0 to 6 hours, to 600℃~700℃ at a heating rate of 80℃ / min~120℃ / min from 6 hours to 12 hours, and to 900℃~1000℃ at a heating rate of 50℃ / min~80℃ / min from 12 hours to 20 hours.
[0122] In some embodiments, in step S3, the holding time in the 500℃~700℃ range is 1h~2h. Appropriately extending the holding time in the 500℃~700℃ range can promote the full reaction between low-rank coal and coking coal additives, ultimately improving the hot properties of the coke.
[0123] To make the objectives, technical solutions, and advantages of this application clearer and more concise, the following specific embodiments are used for illustration, but this application is by no means limited to these embodiments. The embodiments described below are merely preferred embodiments of this application and can be used to describe this application, but should not be construed as limiting the scope of this application. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
[0124] To better illustrate this application, the following description, in conjunction with specific embodiments, further explains its content. The following are specific embodiments.
[0125] Example 1
[0126] A method for preparing a coking coal additive is as follows:
[0127] 1) Preparation of modified clay: Montmorillonite and a 3% (w / w) aqueous solution of silane coupling agent were placed in a reaction vessel at a mass ratio of 1:5 and stirred at 70°C for 2 hours to ensure that the silane coupling agent was fully in contact with the surface of montmorillonite. After the reaction, solid-liquid separation was performed using a vacuum filtration device. The filter cake was dried to constant weight in a 100°C forced-air drying oven and finally pulverized by an air jet mill to obtain modified clay with a particle size of 20 μm.
[0128] 2) Preparation of organic binder: Medium-temperature coal tar with a softening point of 80℃ was subjected to a process at 160℃ to remove light components, yielding a heavy coal tar component (containing 50% pitch, 12% anthracene, 10% phenanthrene, 6% pyrene, and the remainder being heterocyclic compounds). The boiling point of the heavy coal tar component was 380℃. Polyvinyl alcohol with a degree of polymerization of 1750 was dissolved in hot water at 85℃ to prepare a 12% (w / w) polyvinyl alcohol aqueous solution. The heavy coal tar component and the polyvinyl alcohol aqueous solution were mixed at a mass ratio of 3:1 (heavy coal tar component to pure polyvinyl alcohol) to obtain the organic binder.
[0129] 3) Mixing: Weigh 20 parts of modified clay, 10 parts of organic binder, 5 parts of potassium permanganate and 3 parts of ferric nitrate, add each raw material to 30 parts of water, stir and mix at 50°C for 1 hour to obtain coking coal additive.
[0130] A coking method includes the following steps:
[0131] S1, Coal Blending for Coking: By mass percentage, 30% coking coal, 20% fat coal, 15% gas coal, and 35% low-rank coal (moisture content of 20%, ash content of 10%, and volatile matter content of 22%) are mixed to form raw coal, which is then crushed to a particle size of less than 3mm.
[0132] S2, add 1% by weight of the coking coal additive obtained in step 3) above, mix in a coal mixer for 10 minutes, and compact under 20 MPa pressure for 3 minutes to form a density of 1.1 t / m³. 3 coal briquettes;
[0133] S3, the coal briquettes are fed into a 900℃ coke oven for coking for 18 hours to produce coke.
[0134] Example 2
[0135] A method for preparing a coking coal additive is as follows:
[0136] 1) Preparation of modified clay: Montmorillonite and a 4% (w / w) aqueous solution of silane coupling agent were placed in a reaction vessel at a mass ratio of 1:6 and stirred at 75°C for 2.5 h to ensure that the silane coupling agent was fully in contact with the surface of the montmorillonite. After the reaction, solid-liquid separation was performed using a vacuum filtration device. The filter cake was dried to constant weight in a 90°C forced-air drying oven and finally pulverized by an air jet mill to obtain modified clay with a particle size of 25 μm.
[0137] 2) Preparation of organic binder: Medium-temperature coal tar with a softening point of 75℃ was subjected to a process at 170℃ to remove light components, yielding a heavy coal tar component (containing 45% pitch, 13% anthracene, 11% phenanthrene, 7% pyrene, with the remainder being heterocyclic compounds), the boiling point of which was 400℃; polyvinyl alcohol with a degree of polymerization of 1780 was completely dissolved in hot water at 88℃ to obtain a 13% (w / w) polyvinyl alcohol aqueous solution; the heavy coal tar component and the polyvinyl alcohol aqueous solution were mixed at a mass ratio of 4:1 (heavy coal tar component to pure polyvinyl alcohol) to obtain the organic binder;
[0138] 3) Mixing: Weigh 25 parts of modified clay, 13 parts of organic binder, 8 parts of potassium dichromate and 6 parts of ferric chloride, add each raw material to 40 parts of ethanol, stir and mix at 60°C for 1.5 hours to obtain coking coal additive.
[0139] A coking method includes the following steps:
[0140] S1, Coal Blending for Coking: By mass percentage, 35% coking coal, 22% fat coal, 18% gas coal, and 25% low-rank coal (moisture content of 18%, ash content of 9%, and volatile matter content of 20%) are mixed to form raw coal, which is then crushed to a particle size of less than 3mm.
[0141] S2, add 2% by weight of the coking coal additive obtained in step 3) above, mix in a coal mixer for 12 minutes, and compact under 25 MPa pressure for 4 minutes to form a mixture with a density of 1.12 t / m³. 3 coal briquettes;
[0142] S3, the coal briquettes are fed into a 950℃ coke oven for coking for 20 hours to produce coke.
[0143] Example 3
[0144] A method for preparing a coking coal additive is as follows:
[0145] 1) Preparation of modified clay: Montmorillonite and a 5% silane coupling agent aqueous solution were placed in a reaction vessel at a mass ratio of 1:8 and stirred at 80°C for 3 hours to ensure that the silane coupling agent was fully in contact with the surface of the montmorillonite. After the reaction, solid-liquid separation was performed using a vacuum filtration device. The filter cake was dried to constant weight in a 95°C forced-air drying oven and finally pulverized by an air jet mill to obtain modified clay with a particle size of 30 μm.
[0146] 2) Preparation of organic binder: Medium-temperature coal tar with a softening point of 85℃ was subjected to a process at 175℃ to remove light components, yielding a heavy coal tar component (containing 55% pitch, 11% anthracene, 9% phenanthrene, 7% pyrene, and the remainder being heterocyclic compounds), with a boiling point of 420℃; polyvinyl alcohol with a degree of polymerization of 1720 was completely dissolved in hot water at 90℃ to form a 14% (w / w) polyvinyl alcohol aqueous solution; the heavy coal tar component and the polyvinyl alcohol aqueous solution were mixed at a mass ratio of 5:1 to obtain the organic binder;
[0147] 3) Mixing: Weigh 30 parts of modified clay, 15 parts of organic binder, 10 parts of potassium permanganate and 8 parts of ferric nitrate by weight, add each raw material to 50 parts of water, stir and mix at 70°C for 2 hours to obtain coking coal additive.
[0148] A coking method includes the following steps:
[0149] S1, Coal Blending for Coking: By mass percentage, 40% coking coal, 25% fat coal, 20% gas coal, and 15% low-rank coal (moisture content of 22%, ash content of 11%, and volatile matter content of 24%) are mixed to form raw coal, which is then crushed to a particle size of less than 3mm.
[0150] S2, add 3% by weight of the coking coal additive obtained in step 3) above, mix in a coal mixer for 15 minutes, and compact under 30 MPa pressure for 5 minutes to form a mixture with a density of 1.15 t / m³. 3 coal briquettes;
[0151] S3, the coal briquettes are fed into a 1000℃ coke oven for coking for 24 hours to produce coke.
[0152] Example 4
[0153] Example 4 is basically the same as Example 1, except that in step 1), the mass fraction of silane coupling agent in the aqueous solution of silane coupling agent is 4%.
[0154] Example 5
[0155] Example 5 is basically the same as Example 1, except that in step 2), the mass fraction of polyvinyl alcohol in the polyvinyl alcohol solution is 15%.
[0156] Example 6
[0157] Example 6 is basically the same as Example 1, except that in step 1), the particle size of the modified clay is 50 μm.
[0158] Example 7
[0159] Example 7 is basically the same as Example 1, except that in step 3), the modified clay is 30 parts.
[0160] Comparative Example 1
[0161] Using a traditional coal blending method, the raw coal composition, by mass percentage, is 40% coking coal, 25% fat coal, 20% gas coal, and 15% low-rank coal. No coking coal additives of this application are added. Other coking process parameters are the same as in Example 3, and coke is produced.
[0162] Comparative Example 2
[0163] Comparative Example 2 is basically the same as Example 1, except that in step 1), an equal mass of unmodified montmorillonite is used instead of alkyl coupling agent-modified montmorillonite.
[0164] Comparative Example 3
[0165] Comparative Example 3 is basically the same as Example 1, except that in step 2), an equal mass of coal tar heavy components is used to replace the polyvinyl alcohol aqueous solution.
[0166] Comparative Example 4
[0167] Comparative Example 4 is basically the same as Example 1, except that in step 3), 20 parts of organic binder are added.
[0168] Comparative Example 5
[0169] Comparative Example 5 is basically the same as Example 1, except that in step 3), potassium permanganate is replaced with an equal mass of modified clay.
[0170] Comparative Example 6
[0171] Comparative Example 6 is basically the same as Example 1, except that in step 3), ferric nitrate is replaced with an equal mass of modified clay.
[0172] The cokes prepared in each embodiment and each comparative example were subjected to performance tests, and the test results are shown in Table 1 below.
[0173] The test conditions or standards for each performance test item are as follows:
[0174] Coke hot strength and coke reactivity: determined according to GB / T 4000-2017 "Test Method for Coke Reactivity and Post-Reaction Strength".
[0175] Table 1
[0176]
[0177] In Table 1, the amount of coking coal additives refers to the percentage of the mass of the coking coal additives to the mass of the raw coal; the mass content of low-rank coal refers to the percentage of the mass of low-rank coal to the mass of the raw coal.
[0178] As shown in Table 1 above, adding the coking coal additives prepared in the examples during coking coal blending can increase the proportion of low-rank coal in the raw coal. Moreover, under the premise of increasing the proportion of low-rank coal, the resulting coke has high hot strength and low reactivity. Specifically, when 15% to 35% of low-rank coal is added, the hot strength (CSR) of the coke prepared in Examples 1 to 3 is increased by 5% to 10% compared with the comparative example, and the reactivity (CRI) is reduced by 4% to 7%, effectively improving the hot performance of the coke.
[0179] Furthermore, comparing Example 4 with Example 1, it can be seen that when the mass fraction of silane coupling agent in the aqueous solution is 3.5%~4.5%, the resulting coke has higher hot strength and lower reactivity. Comparing Example 5 with Example 1, it can be seen that when the mass fraction of polyvinyl alcohol in the polyvinyl alcohol solution is 14%~15%, the resulting coke has higher hot strength and lower reactivity. Comparing Example 6 with Example 1, it can be seen that when the particle size of the silane coupling agent-modified montmorillonite is 15µm~35µm, the resulting coke has higher hot strength and lower reactivity. Comparing Example 7 with Example 1, it can be seen that when the mass fraction of modified clay is 25 parts~30 parts, the resulting coke has higher hot strength and lower reactivity.
[0180] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0181] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A coking coal additive, characterized in that, The coking coal additive comprises the following raw material components by weight: 20 to 30 parts of modified clay, 10 to 15 parts of organic binder, 5 to 10 parts of oxidant, 3 to 8 parts of pyrolysis catalyst and 30 to 50 parts of first solvent. The modified clay includes silane coupling agent modified montmorillonite; The organic binder includes coal tar heavy components and polyvinyl alcohol.
2. The coking coal additive as described in claim 1, characterized in that, The average particle size of the silane coupling agent modified montmorillonite is 10µm~50µm.
3. The coking coal additive as described in claim 1, characterized in that, The coal tar heavy components, by mass percentage, include 40% to 60% bitumen, 10% to 25% anthracene compounds, 8% to 25% phenanthrene compounds, and 5% to 10% pyrene compounds; And / or, The boiling point of the heavy coal tar components is 350℃~450℃; and / or, The degree of polymerization of the polyvinyl alcohol is 1700~1800; and / or, The mass ratio of the coal tar heavy component to the polyvinyl alcohol is 3:1 to 5:
1.
4. The coking coal additive according to any one of claims 1 to 3, characterized in that, The oxidant includes at least one of potassium permanganate and potassium dichromate; and / or The pyrolysis catalyst includes an iron-based catalyst.
5. A method for preparing a coking coal additive, characterized in that, Includes the following steps: The coking coal additive is prepared by mixing the modified clay, the organic binder, the oxidant and the pyrolysis catalyst in the first solvent according to the mass ratio of the raw material components of the coking coal additive according to any one of claims 1 to 4.
6. The method for preparing coking coal additives as described in claim 5, characterized in that, The method for preparing the modified clay includes the following steps: Montmorillonite and a silane coupling agent are reacted in a second solvent under heating conditions to obtain a mixture; wherein the mass fraction of the silane coupling agent in the second solvent is 3%~5%; the mass ratio of the montmorillonite to the silane coupling agent and the total mass of the second solvent is 1:5~8; the heating temperature is 60℃~80℃; and the heating time is 2h~3h. The mixture is then subjected to solid-liquid separation. The solid phase after solid-liquid separation is dried to obtain the silane coupling agent modified montmorillonite; the drying temperature is 80℃~100℃.
7. The method for preparing coking coal additives as described in claim 5 or 6, characterized in that, The method for preparing the organic binder includes the following steps: The light components of coal tar are removed by heating, and the heavy components of coal tar are obtained. Polyvinyl alcohol is dissolved in a third solvent under heating conditions to obtain a polyvinyl alcohol solution; The coal tar heavy components are mixed with the polyvinyl alcohol solution to obtain the organic binder; The mass ratio of the coal tar heavy component to the polyvinyl alcohol solution is 3-5:1; the mass fraction of polyvinyl alcohol in the polyvinyl alcohol solution is 10%-15%.
8. A coking coal composition, characterized in that, It includes raw coal and coking coal additives as described in any one of claims 1 to 4, wherein the raw coal includes coking coal and low-rank coal.
9. The coking coal composition as described in claim 8, characterized in that, The mass ratio of the coking coal additive to the raw coal is 1% to 3%; and / or, In the raw coal, the mass content of the low-rank coal is 15% to 25%; and / or, The low-rank coal includes at least one of lignite and long-flame coal; and / or, The coking coal includes at least one of coking coal, fat coal, and gas coal.
10. A coking method, characterized in that, Includes the following steps: S1: Mix coking coal with low-rank coal to prepare raw coal; the mixing temperature is 30℃~40℃. S2: Add the coking coal additive according to any one of claims 1 to 4 to the raw coal, mix and form coal cake; the density of the coal cake is 1.05 t / m³. 3 ~1.15t / m 3 ; S3: The coal cake is coked to obtain coke; the coking time is 18h~24h; the coking temperature is 900℃~1000℃; the coking adopts a segmented heating method, heating to 400℃~450℃ at a heating rate of 100℃ / min~150℃ / min from 0h to 6h, heating to 600℃~700℃ at a heating rate of 80℃ / min~120℃ / min from 6h to 12h, and heating to 900℃~1000℃ at a heating rate of 50℃ / min~80℃ / min from 12h to 20h.