CN118447952A - Method for predicting coke quality using coking coal vitrinite reflectance, inert component content and Gibbs maximum fluidity - Google Patents

Abstract

The present invention relates to a method for predicting the quality of coke by using the vitrinite reflectance, inert component content and Gibbs maximum fluidity of coking coal. The quality characteristics of a single type of coal are characterized and quantified by using the vitrinite reflectance, inert component content and Gibbs maximum fluidity. A ternary control diagram of coke crushing strength, coke abrasion resistance, coke thermal reactivity and coke post-reaction strength is established by a mathematical method. The quality of coking coal is evaluated and effective guidance is provided for coking coal blending, thereby achieving the purpose of controlling and improving the quality of coke.

Description

Method for predicting coke quality using coking coal vitrinite reflectance, inert component content and Gibbs maximum fluidity

Technical Field

The invention relates to the technical field of coking, and in particular to a method for predicting coke quality by using vitrinite reflectance, inert component content and Gibbs maximum fluidity of coking coal.

Background technique

Coke is an irregular carbonaceous porous body containing cracks and defects. Coke is the main raw material for blast furnace smelting. It should have a high cold strength in the blast furnace to resist the mechanical impact and wear of the coke during the descent of the block belt. The crushing strength of coke refers to the ability of coke to resist external impact without breaking along the cracks or defects of the structure. The wear resistance of coke refers to the ability of coke to resist friction without producing surface debris or powder.

In recent years, with the development of blast furnace smelting technology, especially the development of large-scale blast furnace volume, high wind temperature technology and blast oxygen-enriched coal injection technology, the role of coke in the blast furnace as a material column skeleton and the role of coke in ensuring air and liquid permeability have become more prominent. Not only is it required that the coke in the blast furnace has a certain crushing strength (to support the upper furnace charge) and a certain wear resistance to maintain the air permeability of the blast furnace, but also higher requirements are placed on the thermal reactivity of coke and the strength of coke after reaction.

The thermal reactivity of coke mainly simulates the ability of coke to react with CO2 gasification (dissolution reaction) before entering the tuyere whirlpool zone in the blast furnace. Coke reacts with carbon dioxide to gasify, and the erosion causes coke weight loss and cracks, and the internal pore wall becomes thinner, which reduces the strength of coke and accelerates the damage of coke. If the reactivity of coke in the soft melting zone is too large, it will lead to poor gas utilization, increased coke ratio, and more fragments and coke powder produced by coke damage, which will also deteriorate the permeability of the blast furnace charge column and affect the smooth operation of the blast furnace. The thermal reactivity of coke has a great impact on blast furnace smelting and has become one of the key factors limiting the stable, balanced, high-quality and efficient production of molten iron in the blast furnace. In order to increase the carbon dioxide content in the top gas, improve the gas utilization, make the furnace temperature and gas flow distribution more reasonable, the charge descends smoothly, and improve the supporting role of the coke skeleton, it is required that the thermal reactivity (CRI) of coke at a certain temperature be as small as possible.

Coke strength after reaction (CSR) measures the ability of coke to maintain high temperature strength under the corrosion of CO2 and alkali metals. Coke undergoes gasification reaction with carbon dioxide, and the corrosion causes coke weight loss and cracks, thinning the internal pore wall, reducing coke strength and accelerating coke breakage. If the reactivity of coke in the soft melting zone is too large, it will lead to poor gas utilization, increased coke ratio, and more fragments and coke powder produced by coke breakage, which will also deteriorate the permeability of the blast furnace charge column and affect the smooth operation of the blast furnace. The strength of coke after reaction has a great impact on blast furnace smelting and has become one of the key factors limiting the stable, balanced, high-quality and efficient production of molten iron in blast furnaces. In order to increase the carbon dioxide content in the top gas, improve the gas utilization, make the furnace temperature and gas flow distribution more reasonable, the charge descends smoothly, and improve the supporting role of the coke skeleton, the strength of coke after reaction (CSR) at a certain temperature is required to be as high as possible.

The above-mentioned quality requirements for coke have also implicitly put forward higher requirements on the coal blending work for coking. It is necessary to conduct in-depth research on the influence of the quality of a single type of coal on the crushing strength, wear resistance, thermal reactivity and post-reaction strength of coke, establish corresponding control models, and accurately control the coke quality within the range required for blast furnace operation by optimizing coal blending.

Establishing a prediction model and control method for coke crushing strength, coke wear resistance, coke thermal reactivity and coke post-reaction strength is of great significance for coking plants to select economic coal blending ratios, predict and control coke quality and manage coal yards. Different countries have different coal resource conditions, different coking plants have different coal use strategies, and there are also differences in evaluation indicators and testing methods. Coal blending management parameters and prediction methods for coke crushing strength, coke wear resistance, coke thermal reactivity and coke post-reaction strength are also different. In recent years, domestic and foreign researchers have conducted a lot of research work on the goal of improving coke quality by predicting coke crushing strength, coke wear resistance, coke thermal reactivity and coke post-reaction strength, which can be roughly divided into the following types:

(1) Prediction using coal and rock parameters, such as the SI-CBI method (strength index and composition balance index method) in the United States;

(2) Prediction using volatile matter and process parameters, such as the V-Y method (volatile matter-colloidal layer index method), V-G method (volatile matter-bonding index method) commonly used in my country, V-TD method (volatile matter-total expansion method) in the UK, and V-CSN method (volatile matter-crucible expansion number method) in Canada;

(3) Prediction using volatile matter and process parameters, such as the R-G method (vitrinite reflectance-bonding index method) and Japan's MOF method (vitrinite reflectance-Gieve maximum fluidity method);

(4) Use coking process conditions for prediction, such as the German G factor method.

(5) Use the coal ash catalytic index for prediction, such as the MCI index method or the MBI index method.

The properties of coking coal mainly depend on the degree of metamorphism, bonding and melting properties, and the content and ratio of active and inert components in coal. Coal-rock blending uses vitrinite reflectance to characterize the degree of coalification, and uses the content and optimal ratio of inert components to characterize the component balance index, but lacks characterization of the process properties of coal.

However, the composition and structure of coking coal are very complex and extremely heterogeneous. The process parameters mentioned above can only represent the process characteristics of one aspect of coking coal, and are far from reflecting the differences in coal rock components and vitrinite quality.

Coking coals with the same degree of metamorphism and similar coal rock composition may have large differences in coking characteristics. There are limitations in predicting coke crushing strength, coke wear resistance, coke thermal reactivity or coke post-reaction strength based solely on vitrinite reflectance and coal rock component content. The differences and differences in coal rock characteristic parameters are not sufficient to reflect the plastic changes of coking coal during heating. Therefore, it is necessary to introduce parameters that reflect plastic changes to make up for the shortcomings of coal rock parameters.

Summary of the invention

The present invention provides a method for predicting the quality of coke by using the vitrinite reflectance, inert component content and Gibbs maximum fluidity of coking coal. The method is based on the coal-rock blending theory, and adopts parameters such as the vitrinite reflectance, inert component content and Gibbs maximum fluidity of a single coking coal to establish a ternary coal blending model, and establishes control diagrams of the coke crushing strength, coke wear resistance, coke thermal reactivity and coke post-reaction strength, so as to provide effective guidance for coking coal blending and achieve the purpose of controlling and improving the quality of coke.

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for predicting coke quality by using vitrinite reflectance, inert component content and Gibbs maximum fluidity of coking coal, characterizing and quantifying the quality characteristics of a single type of coal by using vitrinite reflectance, inert component content and Gibbs maximum fluidity, and establishing a ternary control chart of coke crushing strength, coke abrasion resistance, coke thermal reactivity and coke post-reaction strength by mathematical method, to evaluate the quality of coking coal and control the coke quality on this basis.

A method for predicting coke quality by using coking coal vitrinite reflectance, inert component content and Gibbs maximum fluidity specifically comprises the following steps:

1) Test the reflectance of vitrinite of a single coal to obtain the reflectance of vitrinite of a single coal

2) Quantification of coal rock maceral components: Test the content of vitrinite V, inertinite I, and exinite E in each type of coal; Assuming that the relative density of the maceral components in coking coal is 1.35 and the relative density of minerals is 2.8, according to the Parr formula, the mass fraction of the minerals is:

1.08×A _d +0.55×S _t,d ……(Formula 1)

Where: A _d —dry basis ash, mass fraction %;

_St,d— total sulfur content on dry basis, mass fraction %;

The mineral volume content MM is corrected by the ash and sulfur content, as shown in formula (2):

The inert component content TI of a single coal is calculated according to formula (3):

TI＝I+MM……(Formula 3)

3) Conduct Gibbs maximum fluidity test to obtain Gibbs maximum fluidity lgMF of a single type of coal;

4) Conducting coke quality tests, including coke crushing strength test, coke abrasion resistance test, coke thermal reactivity test and coke post-reaction strength test; obtaining coke crushing strength M ₄₀ , coke abrasion resistance M ₁₀ , coke thermal reactivity CRI and coke post-reaction strength CSR of a single type of coal;

5) Data normalization; vitrinite reflectance The inert component content TI and Gibbs maximum fluidity lgMF are normalized, and the normalization equation is:

Where: _Ri — normalized property of the ith coal; _ri — property of the ith coal; _rmax — maximum value of property r; _rmin — minimum value of property r;

6) Draw coke quality control charts, including coke crushing strength control chart, coke abrasion resistance control chart, coke thermal reactivity control chart and coke post-reaction strength control chart; where:

The coke crushing strength control chart is based on the vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour map of the coke crushing strength M ₄₀ is established in the triangular coordinate system;

The control chart of coke wear resistance is based on vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour map of the coke wear resistance _M10 is established in the triangular coordinate system;

The control chart of coke thermal reactivity is based on the vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour map of coke thermal reactivity CRI is established in the triangular coordinate system;

The strength control chart of coke after reaction is based on the vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour diagram of the coke post-reaction strength CSR is established in the triangular coordinate system.

Furthermore, in the step 1), the vitrinite reflectance of a single type of coal, i.e., the average maximum reflectance of the vitrinite, is specifically tested according to GB/T 6948-2008 "Method for Microscopic Determination of Vitrinite Reflectance of Coal", with the number of test points being no less than 100 points, and the mean value μ of the test data is calculated, which is the vitrinite reflectance

Furthermore, in the step 2), the contents of vitrinite V, inertinite I and exinite E in each single type of coal are tested according to GB/T 8899-201 "Microscopic components and mineral determination methods of coal".

Furthermore, in the step 3), the maximum fluidity lgMF of a single type of coal is tested according to GB/T 25213-2010 "Plasticity of Coal by Constant Moment Gibbs Plasticity Tester".

Furthermore, in step 4), the coke crushing strength test is performed using a coke oven experiment, as follows:

A single type of coal coke was prepared using a 40kg coke oven; the crushing strength M ₄₀ of the coke was tested using a Micum drum according to GB/T 2006-2008 "Method for determination of mechanical strength of coke"; the coke was vibrated and sieved, and the coke with a particle size greater than 60 mm was subjected to a Micum drum test, and after 100 rotations, the coke was allowed to stand for 1 to 2 minutes, and the obtained coke was sieved at 40 mm and weighed;

Crushing strength of coke: M ₄₀ = m ₁ /m×100% (Formula 5)

Where, m: mass of coke entering the drum, kg;

m ₁ : The mass of coke larger than 40 mm after exiting the drum, kg.

Furthermore, in step 4), the coke wear resistance test is performed using a coke oven experiment, as follows:

A single type of coal coke was prepared using a 40kg coke oven; the coke wear resistance _M10 was tested using a Micum drum according to GB/T 2006-2008 "Method for determination of mechanical strength of coke"; the coke was vibrated and sieved, and the coke with a particle size greater than 60 mm was subjected to a Micum drum test, and after 100 rotations, the coke was allowed to stand for 1 to 2 minutes, and the obtained coke was sieved at 10 mm and weighed;

Coke wear resistance: M ₁₀ = m ₂ /m×100% (Formula 6)

Where, m: mass of coke entering the drum, kg;

m ₂ : The mass of coke less than 10 mm after exiting the drum, kg.

Furthermore, in step 4), the thermal reactivity test of coke is carried out using a coke oven experiment, as follows:

Test the thermal reactivity CRI of coke according to GB/T 4000-2008 "Test Method for Coke Reactivity and Post-Reaction Strength"; take a value greater than 20kg of coke is crushed and reduced with a jaw crusher to obtain 10kg; Circular hole sieve screening, for The coke blocks are crushed and screened again; of coke;

Weigh 200±0.5g of coke is placed in a high-temperature alloy steel reactor or a corundum reactor. After reacting with carbon dioxide at a flow rate of 5L/min at 1100℃±5℃ for 2h, the coke reactivity CRI is expressed as the percentage of coke mass loss.

CRI = (m ₃ -m ₄ )/m×100% (Formula 7)

Where, m ₃ : mass of coke before reaction, g;

m ₄ : Mass of residual coke after reaction, g.

Furthermore, in step 4), the strength test of the coke after reaction is carried out using a coke oven experiment, as follows:

Test the coke post-reaction strength CSR according to GB/T 4000-2008 "Test Method for Coke Reactivity and Post-reaction Strength"; take greater than 20kg of coke is crushed and reduced with a jaw crusher to obtain 10kg of coke. Circular hole sieve screening, for The coke blocks are crushed and screened again; of coke;

Weigh 200±0.5g of coke is placed in a high-temperature alloy steel reactor or a corundum reactor, and reacted with carbon dioxide at a flow rate of 5L/min at 1100℃±5℃ for 2h. After the Type I drum test, the mass fraction of coke with a particle size greater than 10mm in the coke after reaction is used to express the coke strength after reaction (CSR);

CSR = (m ₅ -m ₆ )/m×100% (Formula 8)

Where, m ₅ : the mass of residual coke after reaction, g;

_m6 : The mass of coke with particle size larger than 10 mm after drum rotation, g.

Furthermore, in the step 6), the data analysis methods used include polynomial regression method, inverse distance weighted interpolation method, Kriging method, minimum curvature method, improved Shepard method, natural neighbor method, nearest neighbor method, radial basis function method, linear interpolation triangulation method, moving average method and local polynomial method.

Compared with the prior art, the present invention has the following beneficial effects:

1) Based on the coal-rock blending theory, a ternary coal blending model was established using parameters such as the vitrinite reflectance, inert component content and Gibbs maximum fluidity of a single coking coal. Control charts for coke crushing strength, coke wear resistance, coke thermal reactivity and coke post-reaction strength were established to provide effective guidance for coking coal blending and achieve the purpose of controlling and improving coke quality.

2) Coking coal forms two parts during the coking process: fusible components (active components) and infusible components (inert components); vitrinite reflectance is the most scientific parameter to characterize the degree of coking coal metamorphism. For coking coal at a certain metamorphic stage, only when the inert group and the active component are mixed in the most appropriate ratio can coke with good crushing strength be produced.

3) Gibbs maximum fluidity can reflect both the quantity and quality of colloids. The higher the Gibbs maximum fluidity of coking coal, the better the fluidity of the colloids, which can fully flow between coal particles and bond solid particles to obtain higher quality coke. Gibbs maximum fluidity has a strong ability to distinguish the bonding characteristics of low-metamorphic coking coal and is more sensitive to changes in the properties of coking coal. It is suitable for low-metamorphic coking coal and situations with diverse coal sources.

4) The design indicators of the present invention are reasonable, the quality characteristics of a single coking coal are scientifically characterized and quantified by vitrinite reflectance, inert component content and Gibbs maximum fluidity, and a ternary control chart of four coke quality-related indicators is established by mathematical methods, which effectively overcomes the drawbacks of the current use of coking coal and the coking coal blending process, realizes scientific evaluation of coking coal quality, and provides quantitative guidance for precise control of coke quality, thereby achieving the purpose of stabilizing and improving coke quality.

5) The method of the present invention is simple to operate, easy to implement, and can effectively improve the quality stability of blast furnace coke.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a ternary control diagram of the coke crushing strength M ₄₀ according to an embodiment of the present invention.

FIG. 2 is a predicted region (the shaded portion in the figure) of the coke crushing strength M ₄₀ of coal blending scheme 1 according to an embodiment of the present invention.

FIG. 3 is a predicted region (the shaded portion in the figure) of the coke crushing strength M ₄₀ of coal blending scheme 2 according to an embodiment of the present invention.

FIG. 4 is a predicted region (the shaded portion in the figure) of the coke crushing strength M ₄₀ of coal blending scheme 3 according to an embodiment of the present invention.

FIG. 5 is a ternary control diagram of the coke wear resistance _M10 according to an embodiment of the present invention.

FIG. 6 is a predicted region (the shaded portion in the figure) of the coke wear resistance M ₁₀ of coal blending scheme 1 according to an embodiment of the present invention.

FIG. 7 is a predicted region (the shaded portion in the figure) of the coke wear resistance M ₁₀ of coal blending scheme 2 according to an embodiment of the present invention.

FIG8 is a predicted region (the shaded portion in the figure) of the coke wear resistance strength _M10 of coal blending scheme 3 according to an embodiment of the present invention.

FIG. 9 is a ternary control diagram of the coke thermal reactivity CRI according to an embodiment of the present invention.

FIG. 10 is a diagram showing the predicted region of the coke thermal reactivity CRI for coal blending scheme 1 according to an embodiment of the present invention (the shaded portion in the figure).

FIG. 11 is a diagram showing the predicted region of the CRI of thermal reactivity of coke in coal blending scheme 2 according to an embodiment of the present invention (the shaded portion in the figure).

FIG. 12 is a predicted region of the coke thermal reactivity CRI for coal blending scheme 3 according to an embodiment of the present invention (the shaded portion in the figure).

FIG. 13 is a ternary control diagram of the coke post-reaction strength CSR according to an embodiment of the present invention.

FIG. 14 is a prediction area of the coke post-reaction strength CSR of coal blending scheme 1 according to an embodiment of the present invention (the shaded area in the figure).

FIG. 15 is a prediction area of the coke post-reaction strength CSR of coal blending scheme 2 according to an embodiment of the present invention (the shaded area in the figure).

FIG. 16 is a prediction area (the shaded part in the figure) of the coke post-reaction strength CSR of the coal blending scheme 3 according to an embodiment of the present invention.

Detailed ways

The present invention discloses a method for predicting the quality of coke by using the vitrinite reflectance, inert component content and Gibbs maximum fluidity of coking coal. The quality characteristics of a single type of coal are characterized and quantified by using the vitrinite reflectance, inert component content and Gibbs maximum fluidity. A mathematical method is used to establish a ternary control diagram of the coke crushing strength, coke abrasion resistance, coke thermal reactivity and coke post-reaction strength, so as to evaluate the quality of the coking coal and control the coke quality on this basis.

The method for predicting the quality of coke by using the vitrinite reflectance, inert component content and Gibbs maximum fluidity of coking coal described in the present invention specifically comprises the following steps:

1) Test the reflectance of vitrinite of a single coal to obtain the reflectance of vitrinite of a single coal

2) Quantification of coal rock maceral components: Test the content of vitrinite V, inertinite I, and exinite E in each type of coal; Assuming that the relative density of the maceral components in coking coal is 1.35 and the relative density of minerals is 2.8, according to the Parr formula, the mass fraction of the minerals is:

1.08×A _d +0.55×S _t,d ……(Formula 1)

Where: A _d —dry basis ash, mass fraction %;

_St,d— total sulfur content on dry basis, mass fraction %;

The mineral volume content MM is corrected by the ash and sulfur content, as shown in formula (2):

The inert component content TI of a single coal is calculated according to formula (3):

TI＝I+MM……(Formula 3)

7) Conducting Gibbs maximum fluidity test to obtain the Gibbs maximum fluidity lgMF of a single type of coal;

8) Conducting coke quality tests, including coke crushing strength test, coke abrasion resistance test, coke thermal reactivity test and coke post-reaction strength test; obtaining coke crushing strength M ₄₀ , coke abrasion resistance M ₁₀ , coke thermal reactivity CRI and coke post-reaction strength CSR of a single type of coal;

9) Data normalization; vitrinite reflectance The inert component content TI and Gibbs maximum fluidity lgMF are normalized, and the normalization equation is:

Where: _Ri — normalized property of the ith coal; _ri — property of the ith coal; _rmax — maximum value of property r; _rmin — minimum value of property r;

10) Draw coke quality control charts, including coke crushing strength control chart, coke abrasion resistance control chart, coke thermal reactivity control chart and coke post-reaction strength control chart; where:

The coke crushing strength control chart is based on the vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour map of the coke crushing strength M ₄₀ is established in the triangular coordinate system;

The control chart of coke wear resistance is based on vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour map of the coke wear resistance _M10 is established in the triangular coordinate system;

The control chart of coke thermal reactivity is based on the vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour map of coke thermal reactivity CRI is established in the triangular coordinate system;

The strength control chart of coke after reaction is based on the vitrinite reflectance With the inert component content TI as the X-axis, the Gibbs maximum fluidity lgMF as the Z-axis, the contour diagram of the coke post-reaction strength CSR is established in the triangular coordinate system.

Furthermore, in the step 1), the vitrinite reflectance of a single type of coal, i.e., the average maximum reflectance of the vitrinite, is specifically tested according to GB/T 6948-2008 "Method for Microscopic Determination of Vitrinite Reflectance of Coal", with the number of test points being no less than 100 points, and the mean value μ of the test data is calculated, which is the vitrinite reflectance

Furthermore, in the step 2), the contents of vitrinite V, inertinite I and exinite E in each single type of coal are tested according to GB/T 8899-201 "Microscopic components and mineral determination methods of coal".

Furthermore, in the step 3), the maximum fluidity lgMF of a single type of coal is tested according to GB/T 25213-2010 "Plasticity of Coal by Constant Moment Gibbs Plasticity Tester".

Furthermore, in step 4), the coke crushing strength test is performed using a coke oven experiment, as follows:

A single type of coal coke was prepared using a 40kg coke oven; the crushing strength M ₄₀ of the coke was tested using a Micum drum according to GB/T 2006-2008 "Method for determination of mechanical strength of coke"; the coke was vibrated and sieved, and the coke with a particle size greater than 60 mm was subjected to a Micum drum test, and after 100 rotations, the coke was allowed to stand for 1 to 2 minutes, and the obtained coke was sieved at 40 mm and weighed;

Crushing strength of coke: M ₄₀ = m ₁ /m×100% (Formula 5)

Where, m: mass of coke entering the drum, kg;

m ₁ : The mass of coke larger than 40 mm after exiting the drum, kg.

Furthermore, in step 4), the coke wear resistance test is performed using a coke oven experiment, as follows:

A single type of coal coke was prepared using a 40kg coke oven; the coke wear resistance _M10 was tested using a Micum drum according to GB/T 2006-2008 "Method for determination of mechanical strength of coke"; the coke was vibrated and sieved, and the coke with a particle size greater than 60 mm was subjected to a Micum drum test, and after 100 rotations, the coke was allowed to stand for 1 to 2 minutes, and the obtained coke was sieved at 10 mm and weighed;

Coke wear resistance: M ₁₀ = m ₂ /m×100% (Formula 6)

Where, m: mass of coke entering the drum, kg;

m ₂ : The mass of coke less than 10 mm after exiting the drum, kg.

Furthermore, in step 4), the thermal reactivity test of coke is carried out using a coke oven experiment, as follows:

Test the thermal reactivity CRI of coke according to GB/T 4000-2008 "Test Method for Coke Reactivity and Post-Reaction Strength"; take a value greater than 20kg of coke is crushed and reduced with a jaw crusher to obtain 10kg; Circular hole sieve screening, for The coke blocks are crushed and screened again; of coke;

Weigh 200±0.5g of coke is placed in a high-temperature alloy steel reactor or a corundum reactor. After reacting with carbon dioxide at a flow rate of 5L/min at 1100℃±5℃ for 2h, the coke reactivity CRI is expressed as the percentage of coke mass loss.

CRI = (m ₃ -m ₄ )/m×100% (Formula 7)

Where, m ₃ : mass of coke before reaction, g;

m ₄ : Mass of residual coke after reaction, g.

Furthermore, in step 4), the strength test of the coke after reaction is carried out using a coke oven experiment, as follows:

Test the coke post-reaction strength CSR according to GB/T 4000-2008 "Test Method for Coke Reactivity and Post-reaction Strength"; take greater than 20kg of coke is crushed and reduced with a jaw crusher to obtain 10kg of coke. Circular hole sieve screening, for The coke blocks are crushed and screened again; of coke;

Weigh 200±0.5g of coke is placed in a high-temperature alloy steel reactor or a corundum reactor, and reacted with carbon dioxide at a flow rate of 5L/min at 1100℃±5℃ for 2h. After the Type I drum test, the mass fraction of coke with a particle size greater than 10mm in the coke after reaction is used to express the coke strength after reaction (CSR);

CSR = (m ₅ -m ₆ )/m×100% (Formula 8)

Where, m ₅ : the mass of residual coke after reaction, g;

_m6 : The mass of coke with particle size larger than 10 mm after drum rotation, g.

Furthermore, in the step 6), the data analysis methods used include polynomial regression method, inverse distance weighted interpolation method, Kriging method, minimum curvature method, improved Shepard method, natural neighbor method, nearest neighbor method, radial basis function method, linear interpolation triangulation method, moving average method and local polynomial method.

In order to make the purpose, technical scheme and technical effect of the present invention clearer, the technical scheme in the embodiment of the present invention is now clearly and completely described. However, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. In combination with the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The following three embodiments are described by taking four 52-hole JNX70-2 reheating downward adjustment coke ovens and the coking coal of a large coking enterprise with an annual output of 2.55 million tons of coke as an example.

[Example 1]

Coal blending scheme 1 uses 8 types of coal. The quality characteristics of the individual coals and the coke indicators are shown in Table 1. The parameters of the normalized quality characteristics of the individual coals are shown in Table 2.

Table 1 Quality characteristics of single coal and various coke indicators

Table 2 Parameters of single coal quality characteristics after normalization

The experimental proportions of eight single coals are shown in Table 3. The R weighted value is 48.35 (after normalization), the TI weighted value is 50.786 (after normalization), and the lgMF weighted value is 47.498 (after normalization).

Table 3 Experimental ratio

Coal Type Coal 1 Coal 2 Coal 3 Coal 4 Coal 5 Coal 6 Coal 7 Coal 8 Ratio/% 12 16 18 12 10 14 8 10

This embodiment uses the coke crushing strength ternary control diagram (as shown in FIG1 ) to calculate the crushing strength M ₄₀ of the blended coal (the shaded portion in FIG2 ). The crushing strength M ₄₀ of the coke produced by using a 40kg coke oven in this embodiment is 67.9%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke wear resistance ternary control diagram (as shown in Figure 5) to calculate the wear resistance _M10 of the blended coal (the shaded part in Figure 6). The wear resistance _M10 of the coke produced by the 40kg coke oven in this embodiment is 13.1%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke thermal reactivity ternary control diagram (as shown in Figure 9) to calculate the thermal reactivity CRI of the blended coal (the shaded area in Figure 10). The thermal reactivity CRI of the coke produced by the 40kg coke oven in this embodiment is 28.6%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke post-reaction strength ternary control diagram (as shown in Figure 13) to calculate the post-reaction strength CSR of the blended coal (the shaded part in Figure 14). The post-reaction strength CSR of the coke produced by the 40kg coke oven in this embodiment is 58.9%, which is within the control range of the predicted value and has a very small deviation.

[Example 2]

Coal blending scheme 2 uses 8 types of coal. The quality characteristics of the individual coals and the coke indicators are shown in Table 4. The parameters of the normalized quality characteristics of the individual coals are shown in Table 5.

Table 4 Quality characteristics of single coal and various coke indicators

Table 5 Parameters of single coal quality characteristics after normalization

The experimental proportions of eight single coals are shown in Table 6. The R weighted value is 44.252 (after normalization), the TI weighted value is 51.364 (after normalization), and the lgMF weighted value is 74.694 (after normalization).

Table 6 Experimental ratio

Coal Type Coal 1 Coal 2 Coal 3 Coal 4 Coal 5 Coal 6 Coal 7 Coal 8 Ratio/% 10 20 12 20 16 8 8 6

This embodiment uses the coke crushing strength ternary control diagram (as shown in FIG1 ) to calculate the crushing strength M ₄₀ of the blended coal (the shaded portion in FIG3 ). The crushing strength M ₄₀ of the coke produced by using a 40kg coke oven in this embodiment is 71.2%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke wear resistance ternary control diagram (as shown in Figure 5) to calculate the wear resistance _M10 of the blended coal (the shaded part in Figure 7). The wear resistance _M10 of the coke produced by the 40kg coke oven in this embodiment is 10.9%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke thermal reactivity ternary control diagram (as shown in Figure 9) to calculate the thermal reactivity CRI of the blended coal (the shaded area in Figure 11). The thermal reactivity CRI of the coke produced by the 40kg coke oven in this embodiment is 24.3%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke post-reaction strength ternary control diagram (as shown in Figure 13) to calculate the post-reaction strength CSR of the blended coal (the shaded part in Figure 15). The post-reaction strength CSR of the coke produced by the 40kg coke oven in this embodiment is 62.4%, which is within the control range of the predicted value and has a very small deviation.

[Example 3]

Coal blending scheme 3 uses 6 types of coal. The quality characteristics of the individual coals and the coke indicators are shown in Table 7. The parameters of the normalized quality characteristics of the individual coals are shown in Table 8.

Table 7 Quality characteristics of single coal and various coke indicators

Table 8 Parameters of single coal quality characteristics after normalization

The proposed proportions of six single coals are shown in Table 9. The R weighted value is 68.472 (after normalization), the TI weighted value is 45.776 (after normalization), and the lgMF weighted value is 50.334 (after normalization).

Table 9 Experimental Proportions

Coal Type Coal 1 Coal 2 Coal 3 Coal 4 Coal 5 Coal 6 Ratio/% 8 twenty two 26 20 16 8

This embodiment uses the coke crushing strength ternary control diagram (as shown in FIG1 ) to calculate the crushing strength M ₄₀ of the blended coal (the shaded portion in FIG4 ). The crushing strength M ₄₀ of the coke produced by using a 40kg coke oven in this embodiment is 69.3%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke wear resistance ternary control diagram (as shown in Figure 5) to calculate the wear resistance _M10 of the blended coal (the shaded part in Figure 8). The wear resistance _M10 of the coke produced by the 40kg coke oven in this embodiment is 10.7%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke thermal reactivity ternary control diagram (as shown in Figure 9) to calculate the thermal reactivity CRI of the blended coal (the shaded area in Figure 12). The thermal reactivity CRI of the coke produced by the 40kg coke oven in this embodiment is 25.5%, which is within the control range of the predicted value and has a very small deviation.

This embodiment uses the coke post-reaction strength ternary control diagram (as shown in Figure 13) to calculate the post-reaction strength CSR of the blended coal (the shaded part in Figure 16). The post-reaction strength CSR of the coke produced by the 40kg coke oven in this embodiment is 61.3%, which is within the control range of the predicted value and has a very small deviation.

The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims (10)

1. A method for predicting coke quality by utilizing the reflectivity of coking coal mirror body, the content of inert components and the maximum Gibbs fluidity is characterized in that the quality characteristics of single coal are characterized and quantified by utilizing the reflectivity of the mirror body, the content of inert components and the maximum Gibbs fluidity, a ternary control chart of coke crushing strength, coke wear resistance, coke thermal reactivity and coke strength after reaction is established by adopting a mathematical method, the quality of coking coal is evaluated, and the coke quality is controlled on the basis.

2. The method for predicting coke quality by using the reflectivity of coking coal microscopic bodies, the content of inert components and the maximum Gibbs fluidity according to claim 1, which is characterized by comprising the following steps:

1) Performing a single coal vitrinite reflectance test to obtain a single coal vitrinite reflectance

2) Quantification of coal rock microcomponents: testing the contents of vitrinite V, inertinite I and chitin E in each single coal; assuming a relative density of 1.35 for the micro-components in the coking coal and a relative density of 2.8 for the minerals, the mass fraction of minerals according to the Parr formula is:

1.08XA _d+0.55×S_t,d … … (1)

Wherein: a _d -dry ash, mass fraction;

S _t,d— dry basis total sulfur content, mass percent;

The mineral volume content MM is corrected for ash and sulfur content as shown in formula (2):

Calculating the individual coal inert component content TI according to formula (3):

Ti=i+mm … … (3)

3) Performing a Gibbs maximum fluidity test to obtain a Gibbs maximum fluidity lgMF of single coal;

4) Performing coke quality tests, including a coke crushing strength test, a coke abrasion resistance test, a coke thermal reactivity test and a coke post-reaction strength test; obtaining the coke crushing strength M ₄₀, the coke abrasion resistance M ₁₀, the coke thermal reactivity CRI and the coke strength CSR of single coal after reaction;

5) Normalizing the data; reflectivity to mirror body The inert component content TI and the Gibbs maximum fluidity lgMF are normalized, and the normalization equation is as follows:

Wherein: r _i -properties normalized for the i-th single coal; r _i -properties of the i-th single coal; r _max -the maximum value of property r; r _min -minimum of property r;

6) Drawing a coke quality control chart, including a coke crushing strength control chart, a coke wear resistance control chart, a coke thermal reactivity control chart and a coke post-reaction strength control chart; wherein:

Coke crushing strength control chart is based on specular reflectivity Establishing a contour map of coke crushing strength M ₄₀ in a triangular coordinate system by taking the inert component content TI as an X axis and the Gibbs maximum fluidity lgMF as a Z axis;

The coke wear-resistant strength control chart is based on the reflectivity of a mirror body Establishing a contour map of the coke wear resistance M ₁₀ in a triangular coordinate system by taking the inert component content TI as an X axis and the Gibbs maximum fluidity lgMF as a Z axis;

coke thermal reactivity control is based on specular reflectance Establishing a contour map of coke thermal reactivity CRI in a triangular coordinate system by taking the inert component content TI as an X axis and the Gibbs maximum fluidity lgMF as a Z axis;

Intensity control graph after coke reaction is obtained by using specular reflectivity Taking the inert component content TI as an X axis and the Gibbs maximum fluidity lgMF as a Z axis, and establishing a contour map of the intensity CSR after coke reaction in a triangular coordinate system.

3. The method for predicting coke quality by using coking coal specular reflectivity, inert component content and Gibbs maximum fluidity according to claim 2, wherein in the step 1), the specular reflectivity of a single coal, namely the average maximum specular reflectivity, is tested according to GB/T6948-2008 "microscopic method for measuring specular reflectivity of coal", the number of test points is not less than 100 points, and the average μ of the test data is calculated to be the specular reflectivity

4. The method for predicting coke quality by using the vitrinite reflectance, the content of inert components and the maximum fluidity of Gibbs of coking coals according to claim 2, wherein in the step 2), the contents of vitrinite V, inertinite I and chitin E in each single coal are tested according to GB/T8899-201 methods for determining microscopic components and minerals of coals.

5. The method for predicting coke quality by utilizing the reflectivity of coking coal microscopic bodies, the content of inert components and the maximum Gibbs fluidity according to claim 2, wherein in the step 3), the maximum Gibbs fluidity lgMF of single coal is tested according to GB/T25213-2010 "plastic constant moment Gibbs method of coal".

6. The method for predicting coke quality by using the reflectivity of coking coal microscopic bodies, the content of inert components and the maximum fluidity of gizzard according to claim 2, wherein in the step 4), the coke crushing strength test is performed by using a coke oven test, specifically comprising the following steps:

Preparing single coal coke by using a 40kg coke oven; according to GB/T2006-2008 method for measuring mechanical strength of coke, micum drum is adopted to test crushing strength M ₄₀ of coke; sieving coke by using a vibrating sieve, carrying out Micum drum test on the coke with the particle size larger than 60mm, standing for 1-2 min after 100 revolutions, sieving the obtained coke by 40mm, and weighing;

Crushing strength of coke: m ₄₀＝m₁/m.times.100% … … (formula 5)

Wherein, m: charging drum coke mass, kg;

m ₁: the mass of coke after the drum is discharged is more than 40mm, kg.

7. The method for predicting coke quality by using the reflectivity of coking coal lens bodies, the content of inert components and the maximum fluidity of Gibbs according to claim 2, wherein in the step 4), the coke abrasion resistance test is performed by using a coke oven experiment, specifically comprising the following steps:

Preparing single coal coke by using a 40kg coke oven; according to GB/T2006-2008 method for measuring mechanical strength of coke, micum drum is adopted to test the wear resistance M ₁₀ of the coke; sieving coke by using a vibrating sieve, carrying out Micum drum test on the coke with the particle size larger than 60mm, standing for 1-2 min after 100 revolutions, sieving the obtained coke by using 10mm, and weighing;

Abrasion resistance of coke: m ₁₀＝m₂/m.times.100% … … (formula 6)

Wherein, m: charging drum coke mass, kg;

m ₂: the mass of coke less than 10mm after the drum is discharged is kg.

8. The method for predicting coke quality using coking coal specular reflectivity, inert content and maximum gizzard fluidity according to claim 2, wherein in step 4), the coke thermal reactivity test is performed using a coke oven test, specifically as follows:

testing the thermal reactivity CRI of the coke according to GB/T4000-2008 method for testing reactivity and strength after reaction; get greater than Crushing and dividing the coke of 20kg by a jaw crusher to obtain 10kg; by usingRound hole sieve screening, for more thanCrushing and sieving the coke blocks; is made intoIs a coke block of (2);

Weighing and weighing 200+/-0.5 G of coke is placed in a high-temperature resistant alloy steel reactor or a corundum reactor, and reacts with carbon dioxide with the flow of 5L/min for 2 hours at the temperature of 1100+/-5 ℃, and the coke reactivity CRI is expressed as the percentage of the mass loss of the coke;

Cri= (m ₃-m₄)/mx100% … … (formula 7)

Wherein, m ₃: coke mass before reaction, g;

m ₄: residual coke mass g after reaction.

9. The method for predicting coke quality by using the reflectivity of coking coal microscopic bodies, the content of inert components and the maximum fluidity of gizzard according to claim 2, wherein in the step 4), the strength test after coke reaction is performed by using a coke oven experiment, specifically comprising the following steps:

Testing the post-reaction strength CSR of the coke according to GB/T4000-2008 method for testing reactivity and post-reaction strength of Coke; get greater than 20Kg of coke, crushing and dividing the coke by a jaw crusher, and dividing the coke into 10kg; by usingRound hole sieve screening, for more thanCrushing and sieving the coke blocks; is made intoIs a coke block of (2);

Weighing and weighing 200+/-0.5 G of coke is placed in a high-temperature resistant alloy steel reactor or a corundum reactor, reacts with carbon dioxide with the flow of 5L/min for 2 hours at 1100+/-5 ℃, and after I-type rotary drum test, the strength CSR of the coke after reaction is expressed by the mass fraction of the coke with the particle size of more than 10mm accounting for the coke after reaction;

Csr= (m ₅-m₆)/mx100% … … (formula 8)

Wherein, m ₅: residual coke mass g after reaction;

m ₆: and g, the mass of the granular coke after the drum is larger than 10mm.

10. The method for predicting coke quality using coking coal specular reflectivity, inert component content and gizzard maximum fluidity according to claim 2, wherein in the step 6), the data analysis method used includes polynomial regression, inverse distance weighted interpolation, kriging, minimum curvature, improved Xie Biede, natural neighbor, nearest neighbor, radial basis function, linear interpolation triangulated, moving average and local polynomials.