Evaluation method for determining smelting performance of metallurgical coke by powder coke rate

Abstract

The invention discloses an evaluation method for determining smelting performance of metallurgical coke according to a coke breeze rate. The evaluation method comprises the following steps: comprehensively analyzing and detecting a to-be-detected sample; the research coke to be analyzed and researched is detected and analyzed; after the thermal reactivity of the coke is poured out of the rotary drum, adding the original detection method that the coke is sieved by a sieve with the size of 10 mm to the method that the coke is sieved by nine-grade sieves with the size of 18 mm, 15 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm and 0.2 mm respectively; analyzing numerical values of various characterization parameters; respectively detecting the porosity, the pore wall and the microscopic structure of the coke which is less than or equal to 3 mm and less than 3 mm after reaction; analyzing various parameters; and a coke smelting performance comprehensive evaluation method system is constructed and formed. According to the method, a conventional detection process is fully utilized to innovatively represent new technical parameters, and the technical problems that the metallurgical coke melting loss process is difficult to effectively evaluate and the metallurgical coke is a black box in a blast furnace are solved.

Description

Technical Field

[0001] The invention belongs to the field of detection technology, and in particular relates to an evaluation method for determining the smelting performance of metallurgical coke by using the powder coke rate. Background Art

[0002] Metallurgical coke is the core raw material for steel production, a pillar industry of the national economy. It is irreplaceable and plays an important role in guaranteeing and supporting the development of the steel industry. Metallurgical coke is the heat source, reducing agent, material column skeleton and penetrant in blast furnace smelting production. It is also the most important means of adjusting parameters in the blast furnace production process. In recent years, with the development and progress of blast furnace smelting technology, especially the rapid development of large-scale blast furnace volume, high wind temperature technology and blast oxygen-enriched coal injection technology, coke, as the skeleton of the material column in the blast furnace, ensures that the air and liquid permeability in the blast furnace is more prominent. The quality of metallurgical coke has a great impact on the modern blast furnace smelting process and has become a key factor restricting the stable, balanced, high-quality and efficient production of molten iron by blast furnaces.

[0003] The smelting performance of metallurgical coke is an important technical quality index of metallurgical coke, which is generally expressed by reactivity (CRI) and post-reaction strength (CSR). However, the index of post-reaction strength (CSR) is a single index at a specified temperature (1100℃) and a specified reaction gas concentration. It can better characterize the smelting performance of coke from one aspect, but due to the complexity of coke and the complexity of the use process in blast furnaces, it is not possible to evaluate metallurgical coke more comprehensively. At the same time, the detection process of coke reactivity and post-reaction strength is long, time-consuming, and cumbersome. Therefore, it is of great significance to carry out a number of innovative tests on the post-testing to further understand the smelting performance of metallurgical coke and reveal the intrinsic quality of coke. At present, the coke detected after the reaction is only calculated according to the standard, and the percentage of coke larger than 10mm in the coke after the reaction is used as the detection index of post-reaction strength (CSR). There is no deeper exploration of the detection process and further processing and research of the samples. This is not conducive to the in-depth study of coke. It will be a missed opportunity for further research on the smelting properties of coke, especially the melting loss capacity, and it is also a waste of the detection process and detection resources. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide an evaluation method for determining the smelting performance of metallurgical coke based on the strength, microstructure and powder coke rate after reaction.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] An evaluation method for determining the smelting performance of metallurgical coke based on the strength, microstructure and powder coke rate after reaction. The principle of the patented method is described as follows:

[0008] Principle 1: After the coke melting reaction, the internal microstructure and properties of coke undergo profound changes, which are manifested as changes in index performance. The changes in index performance can be used to further explore the smelting performance of coke;

[0009] Principle 2: The method of testing the hot performance of coke is a relatively intuitive method for testing the smelting performance of metallurgical coke, which can effectively characterize its smelting performance. However, the characterization parameters of the test are relatively single. In-depth analysis and research on its testing process is required to define other characterization parameters.

[0010] Principle 3: The melting loss reaction of coke in the blast furnace is the most core and critical reaction process of the smelting performance of metallurgical coke, and it is also the concentrated embodiment of the coke performance.

[0011] The present invention provides an evaluation method for determining the smelting performance of metallurgical coke by using the powder coke rate, which specifically comprises the following steps:

[0012] Step 1: Comprehensively analyze and test the samples to be tested, focusing on testing parameters such as coke porosity, pore wall thickness, and coke microstructure;

[0013] Step 2, testing and analyzing the research coke to be analyzed in accordance with the national testing technical standard GB / T4000 "Test Method for Reactivity and Post-Reaction Strength of Metallurgical Coke";

[0014] Step 3, after the coke is poured out from the drum, the original detection method of screening with a 10 mm sieve is increased to screening the reactants with nine sieves of 18 mm, 15 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm and 0.2 mm respectively;

[0015] Step 4, analyzing the values ​​of various characterization parameters in step 3;

[0016] Data analysis should be fully combined with Principle 3. The present invention describes the melting loss capacity of coke in the blast furnace through new characterization parameters after the reaction, thereby providing new parameter support for blast furnace adaptability coke;

[0017] Step 5, detecting the porosity, pore wall and microstructure of the reacted coke with a diameter of ≤3 mm;

[0018] Step 7, analyzing the parameters of step 5;

[0019] Step 8: Construct a comprehensive evaluation method system for coke smelting performance.

[0020] Furthermore, in step 3, after screening with the nine-level sieve, the percentage content of each particle size is calculated.

[0021] Furthermore, in step 3, the coke rate is characterized by the percentage of the weight of particles ≤3 mm to the weight after the reaction.

[0022] Furthermore, in step 3, the fine coke rate is characterized by the percentage of the weight of particles ≤1 mm to the weight after the reaction.

[0023] Furthermore, in step 3, a columnar analysis chart and a trend chart of the sieve material of each particle size are drawn respectively.

[0024] Furthermore, in step 7, the porosity, pore wall and microstructure of the coke before the reaction are combined with the parameters of steps 5 and 6 for analysis and study.

[0025] Compared with the prior art, the beneficial technical effects of the present invention are:

[0026] The present invention provides a technical solution for scientifically and effectively evaluating the smelting performance of metallurgical coke. It makes full use of the conventional detection process and innovatively characterizes the new technical parameters, solving the technical problems that the melting loss process of metallurgical coke is difficult to effectively evaluate and the "black box" of metallurgical coke in the blast furnace. The application of this patent is a new evaluation system method for the use process of metallurgical coke, a more scientific understanding of metallurgical coke, especially the intuitive parameter characterization of the melting loss process of metallurgical coke in the blast furnace, which provides a systematic method for re-understanding metallurgical coke and a cognitive method for using quality differentiated coke in blast furnaces of different volumes. It has important and practical significance for the stable operation of blast furnaces and the improvement of economic indicators. At the same time, it has good guiding significance for scientific coal blending, optimizing the coal blending technical structure, and reducing the cost of coal blending and coking, thus generating huge economic benefits and good social benefits. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0028] The present invention discloses an evaluation method for determining the smelting performance of metallurgical coke by using the strength, microstructure and powder coke rate after reaction. The principle of the patent method is described as follows:

[0029] Principle 1: After the coke melting reaction, the internal microstructure and properties of coke undergo profound changes, which are manifested as changes in index performance. The changes in index performance can be used to further explore the smelting performance of coke;

[0030] Principle 2: The method of testing the hot performance of coke is a relatively intuitive method for testing the smelting performance of metallurgical coke, which can effectively characterize its smelting performance. However, the characterization parameters of the test are relatively single. In-depth analysis and research on its testing process is required to define other characterization parameters.

[0031] Principle 3: The melting loss reaction of coke in the blast furnace is the most core and critical reaction process of the smelting performance of metallurgical coke, and it is also the concentrated embodiment of the coke performance.

[0032] An evaluation method for determining the smelting performance of metallurgical coke based on the strength, microstructure and coke powder rate after reaction, the specific implementation steps are as follows:

[0033] Step 1: Comprehensively analyze and test the samples to be tested, focusing on testing parameters such as coke porosity, pore wall thickness, and coke microstructure;

[0034] Step 2, testing and analyzing the research coke to be analyzed in accordance with the national testing technical standard GB / T4000 "Test Method for Reactivity and Post-Reaction Strength of Metallurgical Coke";

[0035] Step 3, after the coke is poured out from the drum, the original detection method of screening with a 10 mm sieve is increased to screening the reactants with nine sieves of 18 mm, 15 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm and 0.2 mm respectively;

[0036] Furthermore, after screening with the nine-level sieve, the percentage of each particle size is calculated;

[0037] Furthermore, the coke powder rate is characterized by the percentage of the weight of particles ≤3 mm to the weight after the reaction;

[0038] Furthermore, the fine coke rate is characterized by the percentage of the weight of particles ≤1 mm to the weight after the reaction;

[0039] Furthermore, the columnar analysis chart and trend chart of the oversize materials of each particle size are drawn respectively;

[0040] Step 4, analyzing the values ​​of various characterization parameters in step 3;

[0041] Furthermore, data analysis should be fully combined with Principle 3. This patent describes the melting loss capacity of coke in the blast furnace through new characterization parameters after the reaction, thereby providing new parameter support for blast furnace adaptability coke;

[0042] Step 5, detecting the porosity, pore wall and microstructure of the reacted coke with a diameter of ≤3 mm;

[0043] Step 7, analyzing the parameters of step 5;

[0044] Furthermore, the porosity, pore wall and microstructure of the coke before the reaction were combined with the parameters of step 5 and step 6 for analysis and study;

[0045] Step 8: Construct a comprehensive evaluation method system for coke smelting performance.

[0046] The present invention provides a technical solution for scientifically and effectively evaluating the smelting performance of metallurgical coke. It makes full use of the conventional detection process and innovatively characterizes the new technical parameters, solving the technical problems that the melting loss process of metallurgical coke is difficult to effectively evaluate and the "black box" of metallurgical coke in the blast furnace. The application of this patent is a new evaluation system method for the use process of metallurgical coke, a more scientific understanding of metallurgical coke, especially the intuitive parameter characterization of the melting loss process of metallurgical coke in the blast furnace, which provides a systematic method for re-understanding metallurgical coke and a cognitive method for using quality differentiated coke in blast furnaces of different volumes. It has important and practical significance for the stable operation of blast furnaces and the improvement of economic indicators. At the same time, it has good guiding significance for scientific coal blending, optimizing the coal blending technical structure, and reducing the cost of coal blending and coking, thus generating huge economic benefits and good social benefits.

[0047] In order to better illustrate the patented technology, the metallurgical coke produced by the coking plant of a steel joint venture was used to evaluate its smelting performance based on the strength, microstructural properties and coke powder rate after reaction.

[0048] The metallurgical coke production of the steel joint enterprise is produced in a 7-meter top-loading coke oven. The coal blending structure is shown in Table 1.

[0049] Table 1 Coal blending structure

[0050] Coal Type Coking coal 1 / 3 coking coal lean coal Fat coal gas coal Ratio 55 16 9 10 10

[0051] The test samples were comprehensively analyzed and tested, with emphasis on coke porosity, pore wall thickness, coke microstructure and other parameters. The test values ​​are shown in Table 2 below.

[0052] Table 2 Sample test values

[0053] Serial number Technical indicators % Detection value 1 Ash % 12.82 2 Sulfur % 0.86 3 Crushing strength M40% 89.7 4 Wear resistance M10% 5.4 Reactivity CRI% 22.8 5 Post-reaction strength CSR% 68.7 6 Porosity% 46.15 7 Pore ​​wall thickness um 130

[0054] According to the national testing technical standard GB / T4000 "Test Method for Reactivity and Post-Reaction Strength of Metallurgical Coke", the research coke to be analyzed was tested and analyzed; after the coke thermal reactivity was poured out from the drum, the original test method was increased from screening with a 10mm sieve to screening the reactants with nine sieves of 18mm, 15mm, 10mm, 8mm, 5mm, 3mm, 2mm, 1mm and 0.2mm, and the percentage mass of each particle size was calculated. The test data is shown in Table 3.

[0055] Table 3 Proportion of the detected mass of the reactants screened by the nine-level sieve

[0056] Serial number Sieve diameter Mass of material on sieve g Mass% 1 18mm 82.4 53.37％ 2 15mm 20.8 13.47％ 3 10mm 2.8 1.81％ 4 8mm 1.7 1.10％ 5 5mm 1.4 0.91％ 6 3mm 0.6 0.39％ 7 2mm 1.7 1.10％ 8 1mm 2.6 1.68％ 9 0.2mm 24.4 15.80％ 10 <0.2mm 16.0 10.36％

[0057] Through the analysis of the data in the above table, after the thermal performance test of coke, the coke with a diameter of more than 3mm accounts for 71.04% of the total coke after reaction, the coke with a diameter of less than 1mm accounts for 26.16% of the total coke after reaction, and the coke with a diameter of less than 0.2mm accounts for 16% of the total coke after reaction. The analysis of the screening composition of coke after thermal reaction can clearly determine the melting loss of coke under the state of carbon dioxide. The higher the coke pulverization rate, the more intense the melting loss reaction of coke, which means that the ability of coke to resist carbon dioxide is poor, and the quality performance of coke is not good.

[0058] Analyzing the data of the undersize at each level after the thermal reaction of coke, the melting loss reaction of coke in the blast furnace is intuitively characterized by the continuous melting loss of metallurgical coke for the blast furnace, the gradual reduction and fragmentation of coke particle size due to gas erosion, and the increase of coke dust. The corresponding present invention means the increase of coke less than 3 mm after the reaction. Therefore, this indicator can be used to characterize the melting loss ability of metallurgical coke in the blast furnace, thereby providing new parameter support for blast furnace adaptability coke.

[0059] Test the porosity, pore wall and microstructure of the reacted coke with a diameter of ≤3mm. See 4 for the test values.

[0060] Table 4 Analysis values ​​of pores in coke after reaction above 3 mm

[0061]

[0062]

[0063] The different states of gas precipitation form open pores and closed pores. The former is formed when the gas decomposed during the coking process is precipitated through the channel and is therefore connected to the outside world. The latter is formed when the decomposed gas is resisted by the surrounding colloids and cannot precipitate. Most of the coke (more than 90%) is open pores, and the rest is closed pores. The open pores directly affect the carbon dissolution reaction of the coke, and thus affect the strength; while the closed pores affect the matrix structure of the coke. During the carbon dissolution reaction, the open pores continue to merge and grow, which may cause the closed pores to penetrate and affect the reactivity of the coke. From the data analysis in Table 4, after the reaction, the porosity of the coke increases, the pore wall becomes thinner, and the average pore diameter increases, all of which indicate that the coke is melting and the internal structure of the coke is undergoing profound changes.

[0064] Through the above-mentioned implementation process of the patent, a comprehensive evaluation method system for coke smelting performance is constructed to guide the stable operation of the blast furnace.

[0065] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for evaluating the smelting performance of metallurgical coke by using the coke powder rate, characterized in that: The specific steps include: Step 1, comprehensively analyzing and testing the test samples, focusing on testing the coke porosity, pore wall thickness, and coke microstructure parameters; Step 2, testing and analyzing the research coke to be analyzed in accordance with the national testing technical standard GB / T4000 "Test Method for Reactivity and Post-Reaction Strength of Metallurgical Coke"; Step 3, after the coke is poured out from the drum, the original detection method of screening with a 10 mm sieve is increased to screening the reactants with nine sieves of 18 mm, 15 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm and 0.2 mm respectively; Step 4, analyzing the values ​​of various characterization parameters in step 3; The melting loss capacity of coke in the blast furnace is described by the new characterization parameters after the reaction, thus providing new parameter support for blast furnace adaptability coke; Step 5, detecting the porosity, pore wall and microstructure of the reacted coke with a diameter of ≤3 mm; Step 6, detecting the porosity, pore wall and microstructure of the reacted coke with a diameter of ≤3 mm; Step 7, analyzing the parameters of step 5 and step 6; Step 8: Construct a comprehensive evaluation method system for coke smelting performance.

2. The method for evaluating the smelting performance of metallurgical coke by the powder coke rate according to claim 1, characterized in that: In the step 3, after screening with the nine-stage sieve, the percentage content of each particle size is calculated.

3. The method for evaluating the smelting performance of metallurgical coke by the powder coke rate according to claim 1, characterized in that: In step 3, the coke rate is characterized by the percentage of the weight of particles ≤3 mm to the weight after the reaction.

4. The method for evaluating the smelting performance of metallurgical coke by the powder coke rate according to claim 3, characterized in that: In step 3, the fine coke rate is characterized by the percentage of the weight of particles ≤1 mm to the weight after the reaction.

5. The method for evaluating the smelting performance of metallurgical coke by the powder coke rate according to claim 4, characterized in that: In the step 3, a columnar analysis chart and a trend chart of the sieve material of each particle size are drawn respectively.

6. The method for evaluating the smelting performance of metallurgical coke by the powder coke rate according to claim 1, characterized in that: In step 7, the porosity, pore wall and microstructure of the coke before reaction are combined with the parameters of steps 5 and 6 for analysis and study.

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