A method for testing the alkali resistance strength performance of metallurgical coke

Abstract

The present application belongs to the technical field of metallurgical coke detection, and provides a kind of experimental method for the alkali resistance strength performance of metallurgical coke, comprising: first, take the coke in different parts of blast furnace for alkali metal content determination;Then, according to the alkali metal content of coke in the furnace, configure alkali solution;Then, the coke to be determined is made into sample, then the 180 ℃ sample is soaked in the prepared alkali solution, stirred, mixed uniformly, and soaked for 30 minutes;Take out the coke sample and continue to dry for 2 hours at 180 ℃;Finally, take the coke sample, and do coke thermal reactivity CRI alkali resistance and strength CSR after thermal reaction according to coke thermal reactivity standard;The present experimental method is aimed at the alkali environment of blast furnace of different enterprises, and different alkali solutions are configured by liquid phase method to soak the coke to be detected at high temperature, so as to be closer to the real reaction of the alkali resistance behavior of metallurgical coke in blast furnace.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical coke testing technology, and relates to coke performance testing, specifically a test method for the alkali resistance strength performance of metallurgical coke. Background Technology

[0002] Blast furnace practice has shown that while the cold and hot strength and other conventional properties of the coke fed into the furnace are similar, their performance varies greatly. This is because metallurgical coke undergoes an oxidation-reduction reaction in the high-temperature, alkaline environment of the blast furnace. Differences in the porosity, density, pore wall compactness of the metallurgical coke fed into the furnace, as well as the quality of the coal blending, result in different performance outcomes. Many domestic enterprises and universities have conducted various experimental studies, but ultimately, no effective, feasible, and unified experimental method has been found. Summary of the Invention

[0003] The purpose of this invention is to provide an experimental method for the alkali resistance strength performance of metallurgical coke, which conducts experiments on the alkali resistance strength performance of different cokes under different blast furnace conditions to obtain more realistic, reliable and effective data.

[0004] The technical solution adopted by the present invention to achieve the above objectives is as follows: A test method for the alkali resistance strength of metallurgical coke includes the following steps: S1. Take coke from different parts of the blast furnace, such as the upper part of the tuyere, the lower middle part of the blast furnace body, and the upper middle part of the blast furnace body, and determine the alkali metal content. S2. Prepare an alkaline solution based on the alkali metal content of the coke in the blast furnace; S3. The coke to be tested is made into a spherical or near-spherical sample, dried at 180°C for 2 hours and then cooled. S4. Take the dried and cooled coke sample, heat it at 180℃ for 30 minutes, and then quickly immerse the coke sample in the prepared alkaline solution at 20±5℃. S5. Gently stir the alkaline solution used to soak the coke sample and let it stand for 30 minutes. S6. Remove the coke sample and continue drying it at 180℃ for 2 hours. S7. Weigh the treated coke sample and test the coke thermal reactivity CRI (alkali resistance) and post-thermal strength CSR (alkali resistance).

[0005] Furthermore, the specific process of S1 is as follows: during maintenance, coke from different parts of the blast furnace, including the upper part of the blast furnace tuyeres, the lower middle part of the blast furnace body, and the upper middle part of the blast furnace body, is taken for alkali metal analysis to obtain the average content of potassium oxide and sodium oxide.

[0006] Furthermore, the specific process of S2 includes: S21. Based on the obtained average potassium oxide and sodium oxide contents, prepare potassium carbonate solution and sodium carbonate solution of corresponding concentrations according to the same mass percentage of potassium and sodium metal elements. S22. Mix the potassium carbonate solution and sodium carbonate solution thoroughly.

[0007] Furthermore, the diameter of the spherical sample in S3 is 23-25 ​​mm; Furthermore, before drying the coke sample in step S6, the coke sample is placed on a round-hole sieve with a pore size of 10 mm, left to stand for 2 minutes, and then the sample is gently shaken to remove the alkaline solution from the sample surface.

[0008] Furthermore, the S7 test was conducted according to GB / T4000-2017 Test Method for Reactivity and Post-Reaction Strength of Coke.

[0009] The beneficial effects of this invention are: This experimental method involves preparing alkaline solutions of different concentrations for different blast furnace alkaline environments and conducting corresponding alkali resistance simulation experiments. The alkaline solution prepared by the liquid phase method is used to soak the coke at high temperature, which allows the alkaline solution to completely penetrate the interior of the metallurgical coke, thus more closely reflecting the actual solubility and alkali resistance behavior of metallurgical coke in the blast furnace. Attached Figure Description

[0010] Figure 1 This is a data table of alkali metal analysis of coke extracted from different locations inside the blast furnace in Embodiment 1 of the present invention; Figure 2 This is a table of alkali metal analysis data for different cokes tested in Example 1 of this invention; Figure 3 This is a data table of experimental results on the alkali resistance strength of different cokes in Example 2 of the present invention. Detailed Implementation

[0011] The method of the present invention will be further described below with reference to embodiments: Example 1

[0012] Taking the company's No. 1 blast furnace as an example, the test method for the alkali resistance strength performance of metallurgical coke includes the following steps: S1. During maintenance, take samples of coke from the upper part of the tuyeres of blast furnace No. 1, the lower middle part of the blast furnace body, and the upper middle part of the blast furnace body to determine the alkali metal content and obtain the average potassium oxide and sodium oxide content. S2, such as Figure 1 As shown in the table, based on the obtained average potassium oxide content of 1.03% and sodium oxide content of 0.42%, the same mass percentage of potassium oxide and sodium oxide metal elements was calculated. A 6% potassium carbonate solution and a 3% sodium carbonate solution were prepared in the same 1000ml beaker and thoroughly dissolved and mixed. S3. Prepare 500g of spherical or near-spherical samples with a diameter of 23-25mm from domestic metallurgical top-loading first-grade dry coke, tamped quasi-first-grade dry coke, and third-grade dry coke according to GB / T 1997, and dry them at 180℃ for 2 hours and then cool them. S4. Weigh 230±1 grams of coke sample, heat it again at 180℃ for 30 minutes, and then quickly immerse the coke sample in a mixed solution of 6% potassium carbonate solution and 3% sodium carbonate solution. S5. Gently stir and mix the alkaline solution used to soak the coke sample with a glass rod, and let it stand for 30 minutes. S6. Use tweezers to remove the coke sample from the alkaline solution, place it on a 10mm round hole sieve, let it stand for 2 minutes, then gently shake it to remove the alkaline solution from the sample surface, and continue to dry it at 180℃ for 2 hours. Data after soaking using the above method are as follows Figure 2 As shown in the table, the average alkali metal content is 0.99% potassium oxide and 0.42% sodium oxide, which indicates that it is basically similar to the blast furnace environment (1.03% potassium oxide and 0.42% sodium oxide). Therefore, the method used to treat coke samples to study the alkali metal properties of coke is consistent with the alkali environment of a blast furnace.

[0013] S7. Weigh 200±1g of coke sample and test the coke thermal reactivity CRI (alkali resistance) and thermal post-reaction strength CSR (alkali resistance) according to GB / T4000-2017 Coke Reactivity and Post-Reaction Strength Test Method.

[0014] Alkali resistance test evaluation criteria (production and use requirements): 1. CSR alkali resistance ≥ 45.0; 2. The smaller the strength difference, the better (≤20); 3. Experimental error range (Precision requirements) Repeatability / %: CRI alkali resistance ≤ 2.4, CSR alkali resistance ≤ 4.0; Reproducibility / %: CRI alkali resistance ≤3.2, CSR alkali resistance ≤5.0. Example 2

[0015] The method of this invention was used to conduct experiments on different cokes, including Meijin top-grade dry coke, Haiyan quasi-grade dry coke, Pengfei grade 1 tamped dry coke, Yangguang quasi-grade dry coke, Zhongxin quasi-grade dry coke, Haiyan quasi-grade dry coke, Heli quasi-grade dry coke, Jihai 1.3 sulfur grade 3 tamped dry coke, Baofeng 1.3 sulfur grade 3 tamped dry coke, Baofeng grade 3 wet coke, and Chaitongda tamped quasi-grade dry coke, to obtain the alkali resistance strength test results of these cokes, such as... Figure 3 As shown in the table.

[0016] The method of this invention involves preparing alkali-resistant solutions of different concentrations for different blast furnace alkaline environments of various enterprises, and formulating corresponding alkali-resistant simulation experimental methods. The alkali-resistant experimental methods correspond to the blast furnace alkaline environments of each enterprise. This method is completely different from other methods that use heated solid alkaline substances to form external solid alkaline vapors, which only react on the surface of the coke. The liquid-phase method of preparing alkaline solutions and soaking them at high temperatures allows them to completely penetrate into the interior of the metallurgical coke, thus better reflecting the alkali-resistant behavior of metallurgical coke in the blast furnace.

Claims

1. A test method for the alkali resistance strength of metallurgical coke, characterized in that: Includes the following steps: S1. Take coke from different parts of the blast furnace and determine its alkali metal content. S2. Prepare an alkaline solution based on the alkali metal content of the coke in the blast furnace; S3. Prepare the coke to be tested into spherical or near-spherical samples according to GB / T 1997, dry them at 180℃ for 2 hours, and then cool them. S4. Take the dried and cooled coke sample, heat it at 180℃ for 30 minutes, and then quickly immerse the coke sample in the prepared alkaline solution at 20±5℃. S5. Gently stir the alkaline solution used to soak the coke sample and let it stand for 30 minutes. S6. Remove the coke sample and continue drying it at 180℃ for 2 hours. S7. Weigh the treated coke sample and test its thermal reactivity (CRI) for alkali resistance and its post-thermal reaction strength (CSR) for alkali resistance.

2. The test method for the alkali resistance strength of metallurgical coke according to claim 1, characterized in that: The specific process of S1 is as follows: During maintenance, coke samples are taken from different parts of the blast furnace, including the upper part of the blast furnace tuyeres, the lower middle part of the blast furnace body, and the upper middle part of the blast furnace body, for alkali metal analysis to obtain the average content of potassium oxide and sodium oxide.

3. The test method for the alkali resistance strength of metallurgical coke according to claim 2, characterized in that: The specific process of S2 includes: S21. Based on the obtained average potassium oxide and sodium oxide contents, prepare potassium carbonate solution and sodium carbonate solution of corresponding concentrations according to the same mass percentage of potassium and sodium metal elements. S22. Mix the potassium carbonate solution and sodium carbonate solution thoroughly.

4. The test method for the alkali resistance strength of metallurgical coke according to claim 1, characterized in that: The diameter of the spherical sample in S3 is 23-25 ​​mm.

5. The test method for the alkali resistance strength of metallurgical coke according to claim 1, characterized in that: Before drying the coke sample in step S6, the coke sample is placed on a round hole sieve with a pore size of 10 mm, left to stand for 2 minutes, and then the sample is gently shaken to remove the alkaline solution from the sample surface.

6. The test method for the alkali resistance strength of metallurgical coke according to claim 1, characterized in that: The S7 test was conducted according to GB / T4000-2017 Test Method for Reactivity and Post-Reaction Strength of Coke.

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