Method for testing alkali resistance of coking coal

Abstract

The invention discloses and provides a method for testing the alkali resistance of coking coal, which is used for determining a method and steps for scientifically and accurately representing the alkali resistance of the coking coal by deeply analyzing an alkali resistance mechanism of the coking coal, and provides more thoughts and methods for efficiently using the coking coal. Through construction of the comprehensive evaluation method for the ash components, breakthrough points and core factors of the influence of the alkali resistance of the coking coal are determined, the methods and types of the agents which influence the alkali resistance of the coking coal are determined in sequence, and decisive influence factors of the ash components on the thermal state performance of the coking coal are cleared more clearly. Meanwhile, through the thought setting that K2O, Na2O, CaO, MgO, Fe2O3 and TiO2 reagents are respectively added into the coking coal to be analyzed and researched, fully and uniformly mixed and then independently coked, the problems of inaccurate characterization, great deviation and unclear characterization of the alkali resistance of the coking coal are fundamentally solved, so that a solid foundation is laid for scientific use of the coking coal.

Description

Technical Field

[0001] The present invention belongs to the technical field of the performance evaluation of coking coal and coking with blended coal, and particularly relates to a method for testing the alkali resistance of coking coal. Background Art

[0002] Metallurgical coke is the core raw material for steel production, a pillar industry of the national economy, and is irreplaceable, playing an important guarantee and supporting role in the development of the steel industry. Metallurgical coke is the heat source, reducing agent, burden column skeleton and penetrant in blast furnace smelting production, and is also the most important means for 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 blast furnace volume, high blast temperature technology and oxygen-enriched coal injection technology, coke, as the skeleton of the burden column in the blast furnace, plays a more prominent role in ensuring air and liquid permeability in the blast furnace. The alkali resistance of metallurgical coke is an important characterization method for its role as the blast furnace skeleton. The direct factors affecting the alkali resistance of metallurgical coke are the types and contents of various ash components in coking coal. Coking coal is essentially a fossil formed by ancient plants through extremely complex physical, chemical, biological and geological changes. Different geological environments, different ancient plant cluster varieties, different coal-forming ages, different geological movements and other conditions will all cause huge differences in coal quality. Therefore, the contents of various ash components in coking coal are different, that is, different contents of ash components in coking coal will lead to great differences in its alkali resistance.

[0003] At present, there are different characterization methods for the alkali resistance of coking coal. Some of these methods are too complex and have poor operability, while others are too simple and cannot objectively and effectively characterize the alkali resistance of coking coal. At the same time, for verifying the alkali resistance of coking coal, only potassium hydroxide or sodium hydroxide solution or powder is simply sprayed or sprinkled after smelting coke, which cannot objectively analyze and evaluate the alkali resistance of coking coal, making it difficult to comprehensively and accurately understand and evaluate coking coal, and having an adverse impact on the economic and efficient use of coking coal, forming a restriction.

[0004] Therefore, to solve such problems, we propose a method for testing the alkali resistance of coking coal. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for testing the alkali resistance of coking coal to solve the problems existing in the above-mentioned prior art, with a scientific and rigorous method and intuitive characterization.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for testing the alkali resistance of coking coal according to the present invention includes the following steps:

[0008] Step 1, analysis of the main technical indicators of coking coal, including at least ash content, volatile matter, sulfur content, caking index, and plastic layer index;

[0009] Step 2, analysis of the ash composition of coking coal, mainly including: K2O, Na2O, CaO, MgO, SiO2, Fe2O3, Al2O3, TiO2;

[0010] Step 3, construction of a comprehensive evaluation method for ash composition

[0011] Three representation methods for characterizing ash composition are proposed, namely the strong base index KNI, the total base index TCI, and the ash catalytic equilibrium index AEI;

[0012] The strong base index KNI refers to the sum of the contents of potassium oxide and sodium oxide in the ash composition;

[0013] The total base index TCI refers to the sum of the contents of potassium oxide, sodium oxide, calcium oxide, magnesium oxide, and iron oxide in the ash composition;

[0014] The mathematical expression of the ash catalytic equilibrium index AEI is:

[0015] AEI = [(Na2O + K2O + CaO + MgO + Fe2O3) / (SiO2 + Al2O3 + TiO2)] × 100%

[0016] Step 4, smelting coking coal into coke under specified technical conditions;

[0017] Step 5, analysis of the main technical indicators of coke, mainly including ash content, volatile matter, sulfur content, M40, M10, and hot state properties (reactivity CRI and post-reaction strength CSR);

[0018] Step 6, detection and analysis of the high-temperature thermal properties of coke;

[0019] Step 7, adding reagents of K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 to the coking coal to be analyzed and studied, mixing well, and coking separately;

[0020] Step 8, detection and analysis of the quality technical indicators of the mixed coal sample after adding reagents, including at least ash content, volatile matter, sulfur content, caking index, and plastic layer index;

[0021] Step 9, detection and analysis of the ash composition of the mixed coal sample; <ObjectID=

[0022] Step 10, comprehensive evaluation of the ash composition of the mixed coal sample;

[0023] Step 11, detection and analysis of the ash composition of the coke smelted from the mixed coal sample;

[0024] Step 12, comprehensive evaluation of the ash composition of the coke smelted from the blended coal sample;

[0025] Step 13, analysis of the main technical indicators of the coke smelted from the blended coal sample, mainly including ash content, volatile matter, sulfur content, M40, M10, and thermal properties;

[0026] Step 13, detection and analysis of the high-temperature thermal properties of the coke smelted from the blended coal sample;

[0027] Step 14, the ratio of the coke reactivity index (CRI) and the strength after reaction (CSR) of the coking coal to be analyzed and studied before and after adding reagents becomes the anti-alkali reaction index and the anti-alkali index, denoted as β1 and β2 respectively;

[0028] Step 15, the ratio of the coke high-temperature reactivity index (CRI) and the strength after reaction (CSR) of the coking coal to be analyzed and studied before and after adding reagents becomes the high-temperature anti-alkali reaction index and the high-temperature anti-alkali index, denoted as §1 and §2 respectively;

[0029] Step 16, use the anti-alkali reaction index β1, the anti-alkali index β2, the high-temperature anti-alkali reaction index §1, and the high-temperature anti-alkali index §2 as the evaluation indexes for the anti-alkali performance of coking coal respectively.

[0030] Furthermore, the reaction temperature for the detection and analysis of the high-temperature properties of coke should not be lower than 1300 °C.

[0031] Furthermore, the reagent grades of K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 added should be at least analytical reagent grade.

[0032] Furthermore, the addition ratios of the reagents K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 are determined according to the properties of different coking coals and the requirements of the evaluation tests.

[0033] Furthermore, the thermal properties include the reactivity index (CRI) and the strength after reaction (CSR).

[0034] Furthermore, through the application of the test method for the anti-alkali ability of coking coal, various coking coals can be used more precisely, improving the utilization efficiency of coking coal and saving high-quality and precious coking coal resources; smelting metallurgical coke more suitable for the needs of blast furnaces, providing high-quality raw materials for the stable and high-yield production of blast furnaces.

[0035] Furthermore, this method fundamentally solves the problems of inaccurate characterization, large deviation, and unclear characterization of the anti-alkali ability of coking coal, thus laying a solid foundation for the scientific use of coking coal.

[0036] Compared with the prior art, the beneficial technical effects of the present invention:

[0037] The present invention provides a test method for the alkali resistance of coking coal. By deeply analyzing the mechanism of the alkali resistance of coking coal, the methods and steps for scientifically and accurately characterizing the alkali resistance of coking coal are determined, providing more ideas and methods for the efficient use of coking coal. Through the construction of a comprehensive evaluation method for ash composition, the breakthrough points and core factors affecting the alkali resistance of coking coal are determined. Subsequently, the methods and types of agents added to affect the alkali resistance of coking coal are determined, and the decisive influencing factors of ash composition on the hot-state performance of coking coal are made clearer. At the same time, by setting the idea of separately coking after adding K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 reagents to the coking coal to be analyzed and studied and fully mixing them, the problems of inaccurate, extremely deviated, and unclear characterization of the alkali resistance of coking coal are fundamentally solved. Thereby, a solid foundation is laid for the scientific use of coking coal, and a way of thinking is also provided for the combined use of coking coals with different properties and the melting loss behavior of metallurgical coke in the blast furnace. Overall, through the application of the test method for the alkali resistance of coking coal, various coking coals can be used more precisely, the use efficiency of coking coal can be improved, and high-quality and precious coking coal resources can be saved; metallurgical coke more suitable for the requirements of the blast furnace can be smelted, providing high-quality raw materials for the stable and high-yield production of the blast furnace. This patented method has a broad application prospect, creates considerable economic benefits, and produces good social benefits. Specific embodiments

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] The purpose of the present invention is to provide a test method for the alkali resistance of coking coal to solve the problems existing in the above-mentioned prior art, with clear and accurate principles, scientific and appropriate methods, and obvious effects.

[0040] The present invention provides a test method for the alkali resistance of coking coal, and the technical principle and basic idea for characterizing the alkali resistance of coking coal:

[0041] The root cause of the alkali metal erosion of coking coal is that the alkali metals and alkaline earth metals in its own ash increase the ability of coking coal to cause melting loss after being smelted into coke. The most intuitive and effective means for characterizing the alkali resistance of coking coal is the hot-state performance (reactivity CRI and post-reaction strength CSR), that is, the change in the hot-state performance of the coke smelted after the change in the ash composition of the coking coal, to judge the strength of its alkali resistance.

[0042] The ash composition in coking coal can effectively characterize the change of its thermal strength. The internal reason is that the basic metal oxides in coking coal intensify the intensity of the solution loss reaction of coke during the reaction with carbon dioxide, promote the solution loss reaction of coke in the carbon dioxide environment, make the coke pores larger and the pore walls thinner. The higher the content of basic metals, the more intense the solution loss reaction and the lower the thermal strength of coke.

[0043] It includes the following steps:

[0044] Step 1, analysis of the main technical indexes of coking coal, including at least ash content, volatile matter, sulfur content, caking index, and plastic layer index;

[0045] Step 2, analysis of the ash composition of coking coal, mainly including: K2O, Na2O, CaO, MgO, SiO2, Fe2O3, Al2O3, TiO2;

[0046] Step 3, construction of a comprehensive evaluation method for ash composition

[0047] Three representation methods for characterizing ash composition are proposed, namely the strong base index (KNI), the total base index (TCI), and the ash catalytic equilibrium index (AEI).

[0048] The strong base index (KNI) refers to the sum of the contents of potassium oxide and sodium oxide in the ash composition.

[0049] The total base index (TCI) refers to the sum of the contents of potassium oxide, sodium oxide, calcium oxide, magnesium oxide, and iron oxide in the ash composition.

[0050] The mathematical expression of the ash catalytic equilibrium index (AEI) is:

[0051] AEI = [(Na2O + K2O + CaO + MgO + Fe2O3) / (SiO2 + Al2O3 + TiO2)] × 100%

[0052] Step 4, smelt coking coal into coke under specified technical conditions;

[0053] Step 5, analysis of the main technical indexes of coke, mainly including ash content, volatile matter, sulfur content, M40, M10, and thermal properties (reactivity CRI and post-reaction strength CSR);

[0054] Step 6, detection and analysis of the high-temperature thermal properties of coke;

[0055] Furthermore, the reaction temperature for the detection and analysis of the high-temperature properties of coke should not be lower than 1300 °C;

[0056] Step 7, add K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 reagents to the coking coal to be analyzed and studied respectively, mix well, and then coke separately;

[0057] Furthermore, the reagent grades of K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 added should be at least analytical reagent grade.

[0058] Furthermore, the proportions of the reagents K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 added are determined according to the properties of different coking coals and the requirements of the evaluation tests.

[0059] Step 8, detection and analysis of the quality and technical indicators of the mixed coal sample after adding the reagents, including at least ash content, volatile matter, sulfur content, caking index, and plastic layer index.

[0060] Step 9, detection and analysis of the ash composition of the mixed coal sample.

[0061] Step 10, comprehensive evaluation of the ash composition of the mixed coal sample.

[0062] Step 11, detection and analysis of the ash composition of the coke smelted from the mixed coal sample.

[0063] Step 12, comprehensive evaluation of the ash composition of the coke smelted from the mixed coal sample.

[0064] Step 13, analysis of the main technical indicators of the coke smelted from the mixed coal sample, mainly including ash content, volatile matter, sulfur content, M40, M10, and hot state performance (reactivity CRI and post-reaction strength CSR).

[0065] Step 13, detection and analysis of the high-temperature thermal performance of the coke smelted from the mixed coal sample.

[0066] Furthermore, the reaction temperature for the detection and analysis of the high-temperature performance of the coke should not be lower than 1300 °C.

[0067] Step 14, the ratios of the coke reactivity CRI and post-reaction strength CSR before and after adding the reagents to the coking coal to be analyzed and studied are taken as the anti-alkali reaction index and anti-alkali index, denoted as β1 and β2 respectively.

[0068] Step 15, the ratios of the high-temperature coke reactivity CRI and post-reaction strength CSR before and after adding the reagents to the coking coal to be analyzed and studied are taken as the high-temperature anti-alkali reaction index and high-temperature anti-alkali index, denoted as §1 and §2 respectively.

[0069] Step 16, the anti-alkali reaction index β1, anti-alkali index β2, high-temperature anti-alkali reaction index §1, and high-temperature anti-alkali index §2 are used as the evaluation indicators for the anti-alkali performance of the coking coal.

[0070] The present invention provides a test method for the alkali resistance of coking coal. By deeply analyzing the mechanism of the alkali resistance of coking coal, the methods and steps for scientifically and accurately characterizing the alkali resistance of coking coal are determined, providing more ideas and methods for the efficient use of coking coal. Through the construction of a comprehensive evaluation method for ash composition, the breakthrough points and core factors affecting the alkali resistance of coking coal are determined. Subsequently, the methods and types of agents added to affect the alkali resistance of coking coal are determined, and the decisive influencing factors of ash composition on the hot state performance of coking coal are made clearer. At the same time, by setting the idea of separately coking after adding K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 reagents to the coking coal to be analyzed and studied and fully mixing them, the problems of inaccurate, extremely deviated, and unclear characterization of the alkali resistance of coking coal are fundamentally solved. Thus, a solid foundation is laid for the scientific use of coking coal, and a thinking method is provided for the combined use of coking coals with different properties and the melting loss behavior of metallurgical coke in the blast furnace. Overall, through the application of the test method for the alkali resistance of coking coal, various coking coals can be used more accurately, the use efficiency of coking coal can be improved, and high-quality and precious coking coal resources can be saved; metallurgical coke more suitable for the requirements of the blast furnace can be smelted, providing high-quality raw materials for the stable and high-yield production of the blast furnace. This patented method has a wide application prospect, creates considerable economic benefits, and produces good social benefits.

[0071] Example 1

[0072] To further elaborate on the implementation of the present invention patent, the alkali resistance test was carried out on Coking Coal 1 commonly used in a certain coking plant.

[0073] The main technical indicators of Coking Coal 1, such as ash content, volatile matter, sulfur content, caking index, and plastic layer index, were analyzed; the indicators of the ash composition of coking coal, namely K2O, Na2O, CaO, MgO, SiO2, Fe2O3, Al2O3, and TiO2, were detected; the methods for characterizing ash by ash composition were calculated, and were represented by the strong base index (KNI), total alkali index (TCI), and ash catalytic equilibrium index (AEI) respectively; the specific representation methods are as follows: The strong base index (KNI) refers to the sum of the contents of potassium oxide and sodium oxide in the ash composition. The total alkali index (TCI) refers to the sum of the contents of potassium oxide, sodium oxide, calcium oxide, magnesium oxide, and iron oxide in the ash composition. The mathematical expression of the ash catalytic equilibrium index (AEI) is: AEI = [(Na2O + K2O + CaO + MgO + Fe2O3) / (SiO2 + Al2O3 + TiO2)] × 100%. The analysis results are shown in Table 1-1 and Table 1-2.

[0074] Table 1 Main Technical Indicators of Coking Coal 1-1

[0075] Coal sample name Ad Vdaf St,d G Y Coking coal 1 10.52 24.78 0.92 86 24.5

[0076] Table 1-2 Ash Composition Detection and Characterization Method of Coking Coal 1

[0077]

[0078] The coking coal 1 is smelted into coke under specified technical conditions, and the main technical indexes of the smelted coke, such as ash content, volatile matter, sulfur content, M40, M10, and hot state performance (reactivity CRI and post-reaction strength CSR), are detected and analyzed. The detected values are shown in Table 1-3.

[0079] Table 1-3 Detection of Coke Performance Indexes Smelted from Coking Coal 1

[0080] Name Ad Vdaf St,d M40 M10 CRI CSR Coke made from coking coal 1 13.68 1.42 80.81 89.7 6.4 15.8 73.5

[0081] For the detection and analysis of the high-temperature thermal performance of coke, the reaction temperature for the detection and analysis of the high-temperature performance of coke is 1450 °C, and the detected values are shown in Table 1-4.

[0082] Table 1-4 Detection of High-Temperature Thermal Performance of Coke Smelted from Coking Coal 1

[0083]

[0084] Based on the comprehensive analysis of the performance indexes of coking coal 1, analytical reagent grade experimental reagents K2O, Na2O, CaO, MgO, and Fe2O3 are determined to be added. After thorough mixing, coking is carried out separately, and the masses of the added reagents are shown in Table 1-5.

[0085] Table 1-5 Mass of Alkali Metals Added

[0086] Name of added reagent <![CDATA[Fe2O3]]> CaO MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> Mass g 15 15 15 10 10

[0087] After adding the reagents, the coal samples are mixed evenly for multiple times, and the indexes such as ash content, volatile matter, sulfur content, caking index, and plastic layer index of the coal samples are detected. The detection and analysis of the ash composition of the mixed coal samples are carried out, and the detected values are shown in Tables 1-6 and 1-7.

[0088] Table 1-6 Main Technical Indexes of Coking Coal 1 after Adding Reagents

[0089]

[0090] Table 1-7 Detection and Characterization Method of Ash Composition of Coking Coal 1 after Adding Reagents

[0091]

[0092] The coking coal 1 added with reagents is thoroughly mixed and then smelted into coke under specified technical conditions. The main technical indexes of the smelted coke, such as ash content, volatile matter, sulfur content, M40, M10, and hot state performance (reactivity CRI and post-reaction strength CSR), are detected and analyzed. The detected values are shown in Table 1-8.

[0093] Table 1-8 Detection of Coke Performance Indexes Produced from Coking Coal 1 after Adding Reagents

[0094]

[0095] For the detection and analysis of the high-temperature thermal performance of coke, the reaction temperature for the detection and analysis of the high-temperature performance of coke is 1450 °C, and the detection values are shown in Table 1-9.

[0096] Table 1-9 Detection of High-Temperature Thermal Performance of Coke Produced from Coking Coal 1 after Adding Reagents

[0097] Name Detection temperature condition CRI CSR Coke made from coking coal 1 1450℃ 35.6 52.7

[0098] The ratios of the coke reactivity index (CRI) and the strength after reaction (CSR) of coking coal 1 before and after adding reagents are the anti-alkali reaction index and the anti-alkali index, which are respectively denoted as β1 = 1.70 and β2 = 0.72.

[0099] The ratios of the high-temperature coke reactivity index (CRI) and the strength after reaction (CSR) of coking coal 1 before and after adding reagents are the high-temperature anti-alkali reaction index and the high-temperature anti-alkali index, which are respectively denoted as §1 = 1.20 and §2 = 0.80.

[0100] The anti-alkali reaction index β1, the anti-alkali index β2, the high-temperature anti-alkali reaction index §1, and the high-temperature anti-alkali index §2 are respectively used as the evaluation indexes for the anti-alkali performance of coking coal 1.

[0101] Example 2

[0102] For the separately added analytical pure grade experimental reagent K2O in Example 1, after being fully mixed with coking coal 1, the anti-alkali performance detection is carried out according to the steps of this patent.

[0103] For the separately added analytical pure grade experimental reagent Na2O in Example 1, after being fully mixed with coking coal 1, the anti-alkali performance detection is carried out according to the steps of this patent.

[0104] For the separately added analytical pure grade experimental reagent CaO in Example 1, after being fully mixed with coking coal 1, the anti-alkali performance detection is carried out according to the steps of this patent.

[0105] For the separately added analytical pure grade experimental reagent MgO in Example 1, after being fully mixed with coking coal 1, the anti-alkali performance detection is carried out according to the steps of this patent.

[0106] For the separately added analytical pure grade experimental reagent Fe2O3 in Example 1, after being fully mixed with coking coal 1, the anti-alkali performance detection is carried out according to the steps of this patent.

[0107] Example 3

[0108] To further elaborate on the implementation of this invention patent, the anti-alkali performance of fat coal 2 commonly used in a certain coking plant was tested.

[0109] Analyze the main technical indicators of fat coal 2, namely ash content, volatile matter, sulfur content, caking index, and plastic layer index; detect the indicators of the ash components of coking coal, including K2O, Na2O, CaO, MgO, SiO2, Fe2O3, Al2O3, and TiO2; calculate the ash component characterization methods, which are represented by the strong base index (KNI), total alkali index (TCI), and ash catalytic equilibrium index (AEI) respectively; the specific expression methods are as follows: The strong base index (KNI) refers to the sum of the contents of potassium oxide and sodium oxide in the ash components. The total alkali index (TCI) refers to the sum of the contents of potassium oxide, sodium oxide, calcium oxide, magnesium oxide, and iron oxide in the ash components. The mathematical expression of the ash catalytic equilibrium index (AEI) is: AEI = [(Na2O + K2O + CaO + MgO + Fe2O3) / (SiO2 + Al2O3 + TiO2)] × 100%. The analysis results are shown in Tables 3-1 and 3-2.

[0110] Table 3-1 Main Technical Indicators of Fat Coal 2

[0111] Coal sample name Ad Vdaf St,d G Y Fat coal 2 10.31 26.8 1.20 92 26.5

[0112] Table 3-2 Detection and Characterization Methods of Ash Components of Fat Coal 2

[0113]

[0114] Smelt fat coal 2 into coke under specified technical conditions, and detect and analyze the main technical indicators of the smelted coke, namely ash content, volatile matter, sulfur content, M40, M10, and hot state performance (reactivity CRI and post-reaction strength CSR). The detected values are shown in Table 3-3.

[0115] Table 3-3 Detection of Coke Performance Indexes Smelted from Fat Coal 2

[0116]

[0117] For the detection and analysis of the high-temperature thermal performance of coke, the reaction temperature for the detection and analysis of the high-temperature performance of coke is 1450 °C, and the detected values are shown in Table 3-4.

[0118] Table 3-4 Detection of High-Temperature Thermal Performance of Coke Smelted from Fat Coal 2

[0119]

[0120] Based on the comprehensive analysis of the performance indicators of fat coal 2, determine to add experimental reagents K2O, Na2O, CaO, MgO, and Fe2O3 of analytical reagent grade. After fully mixing, coke is produced separately, and the masses of the added reagents are shown in Table 3-5.

[0121] Table 3-5 Mass of Alkali Metals Added

[0122]

[0123] After adding the reagent, the coal sample was mixed evenly for multiple times, and the ash content, volatile matter, sulfur content, caking index, plastic layer index and other indicators of the coal sample were detected. The detection and analysis of the ash composition of the mixed coal sample were carried out, and the detection values are shown in Table 3-6 and Table 3-7.

[0124] Table 3-6 Main Technical Indicators of Fat Coal 2 after Adding Reagent

[0125]

[0126] Table 3-7 Detection and Characterization Methods of Ash Composition of Fat Coal 2 after Adding Reagent

[0127]

[0128] After thoroughly mixing Fat Coal 2 with the added reagent, coke was smelted under specified technical conditions. The main technical indicators of the smelted coke, such as ash content, volatile matter, sulfur content, M40, M10, and hot state performance (reactivity CRI and post-reaction strength CSR), were detected and analyzed. The detection values are shown in Table 3-8.

[0129] Table 3-8 Detection of Coke Performance Indexes Smelted from Coking Coal 1 after Adding Reagent

[0130]

[0131] The detection and analysis of the high-temperature thermal performance of coke were carried out. The reaction temperature for the detection and analysis of the high-temperature performance of coke was 1450 °C, and the detection values are shown in Table 3-9.

[0132] Table 3-9 Detection of High-Temperature Thermal Performance of Coke Smelted from Fat Coal 2 after Adding Reagent

[0133]

[0134] The ratios of the coke reactivity CRI and the post-reaction strength CSR of Fat Coal 2 before and after adding the reagent are the anti-alkali reaction index and the anti-alkali index, which are respectively recorded as β1 = 1.33 and β2 = 0.87.

[0135] The ratios of the high-temperature coke reactivity CRI and the post-reaction strength CSR of Fat Coal 2 before and after adding the reagent are the high-temperature anti-alkali reaction index and the high-temperature anti-alkali index, which are respectively recorded as §1 = 1.12 and §2 = 0.82.

[0136] The anti-alkali reaction index β1, the anti-alkali index β2, the high-temperature anti-alkali reaction index §1 and the high-temperature anti-alkali index §2 are respectively used as the evaluation indexes for the anti-alkali performance of Coking Coal 1.

[0137] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the spirit of the present invention's design, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A test method for the alkali resistance of coking coal, characterized in that: The steps include: Step 1: Analysis of the main technical indicators of coking coal, including at least ash content, volatile matter, sulfur content, caking index, colloidal layer index. Step 2: Analysis of the components of coking coal ash, mainly including: K2O, Na2O, CaO, MgO, SiO2, Fe2O3, Al2O3, TiO2; Step 3: Construction of comprehensive evaluation method for ash composition Three methods for characterizing ash composition are proposed, namely strong base index KNI, total base index TCI and ash catalytic balance index AEI; The strong alkalinity index KNI refers to the sum of the contents of potassium oxide and sodium oxide in the ash component; Total alkali index (TCI) refers to the sum of the contents of potassium oxide, sodium oxide, calcium oxide, magnesium oxide and iron oxide in the ash components; The mathematical expression of ash catalytic balance index AEI is: AEI=[(Na2O+K2O+CaO+MgO+Fe2O3) / (SiO2+Al2O3+TiO2)]×100% Step 4, smelting the coking coal into coke under specified technical conditions; Step 5: Analysis of the main technical indicators of coke, including ash content, volatile matter, sulfur content, M40, M10, and thermal properties (reactivity CRI and post-reaction strength CSR); Step 6: Detection and analysis of high-temperature thermal properties of coke; Step 7, adding K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 reagents to the coking coal to be analyzed, mixing them thoroughly, and then coking them separately; Step 8: After adding the reagent, the quality technical indicators of the mixed coal sample are tested and analyzed, including at least ash content, volatile matter, sulfur content, caking index, and gelatinous layer index; Step 9, detecting and analyzing the ash components of the mixed coal sample; Step 10, comprehensive evaluation of ash composition of mixed coal sample; Step 11, detecting and analyzing the ash composition of the coke smelted from the mixed coal sample; Step 12, comprehensive evaluation of the ash composition of the coke produced from the mixed coal sample; Step 13: Analyze the main technical indicators of the coke smelted from the mixed coal sample, including ash content, volatile matter, sulfur content, M40, M10, and thermal properties; Step 13, testing and analyzing the high-temperature thermal properties of the coke smelted from the mixed coal sample; Step 14, the ratio of the coke reactivity CRI and the strength CSR after the reaction of the coking coal to be analyzed and studied before and after the addition of the reagent is converted into the alkali resistance reaction index and the alkali resistance index, which are calculated as β1 and β2 respectively; Step 15, the ratio of the high temperature reactivity (CRI) and the post-reaction strength (CSR) of the coking coal before and after the addition of the reagent to be analyzed is converted into the high temperature alkali resistance index and the high temperature alkali resistance index, which are recorded as §1 and §2 respectively; Step 16: using the alkali resistance index β1, the alkali resistance index β2, the high temperature alkali resistance index §1, and the high temperature alkali resistance index §2 as evaluation indicators for the alkali resistance of coking coal, respectively.

2. The test method for the alkali resistance of coking coal according to claim 1, wherein: The reaction temperature for testing and analyzing the high-temperature properties of coke should not be lower than 1300℃.

3. The test method for the alkali resistance of coking coal according to claim 1, characterized in that: The added K2O, Na2O, CaO, MgO, Fe2O3, and TiO2 reagents should be at least analytical grade.

4. The test method for the alkali resistance of coking coal according to claim 1, wherein: The proportion of K2O, Na2O, CaO, MgO, Fe2O3 and TiO2 reagents added is determined according to the properties of different coking coals and the needs of evaluation tests.

5. The test method for the alkali resistance of coking coal according to claim 1, wherein: The hot state properties include the reactivity index CRI and the post-reaction strength CSR.

6. The test method for the alkali resistance of coking coal according to claim 1, characterized in that: Overall, by applying the test method for the alkali resistance of coking coal, various coking coals can be used more precisely, improving the utilization efficiency of coking coal and saving high-quality and precious coking coal resources; smelting metallurgical coke more suitable for the requirements of blast furnaces, providing high-quality raw materials for the stable and high-yield production of blast furnaces.

7. The test method for the alkali resistance of coking coal according to claim 1, characterized in that: This method fundamentally solves the problems of inaccurate, extremely deviated and unclear characterization of the alkali resistance of coking coal, thus laying a solid foundation for the scientific use of coking coal.

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