A method for separation and quantitative characterization of light and heavy phases of colloid-bound phase in coal

Abstract

The present invention discloses a method for separating and quantitatively characterizing the light and heavy phases of a colloid binding phase in coal. The method comprises: weighing multiple base coal samples; not heating one coal sample and heating the remaining coal samples; mixing the coal with acetone, filtering the separated liquid and solid phase to obtain a first extract and a raffinate coal; centrifuging the first extract, taking the supernatant, and treating it as a light extract; drying and weighing the first raffinate coal, and calculating the mass difference between the coal before and after extraction as the mass of the light extract; mixing the first raffinate coal with tetrahydrofuran, filtering the separated liquid and solid phase to obtain a second extract and a raffinate coal; centrifuging the second extract, taking the supernatant, and treating it as a heavy extract; drying and weighing the second raffinate coal, and calculating the mass difference between the coal before and after extraction as the mass of the heavy extract; performing GC-MS analysis on the light and heavy extracts to determine the mass percentages of the light and heavy phases; and multiplying the mass percentages of the light and heavy phases by the masses of the light and heavy extracts to obtain the masses of the light and heavy phases of the colloid binding phase.

Description

Technical Field

[0001] The present invention relates to the technical field of coal coke production, and more particularly to a method for separating and quantitatively characterizing a light and heavy phase of a colloid binding phase in coal. Background Art

[0002] With the expansion of blast furnaces and the development of coal injection technology, challenges to coke quality, particularly strength, are becoming increasingly severe. Although my country boasts abundant coal reserves and a wide variety of coal types, the coal used in coking is primarily gas coal with weaker caking properties, and one-third is coking coal. Strong caking coals (such as fat coal and prime coking coal) account for less than 30%. Furthermore, since approximately 30% of coking coal is high in sulfur and ash, the availability of high-quality coking coal is limited. Therefore, finding a way to produce high-quality coke from low-quality coal has become a key development goal for the coking industry.

[0003] As the primary contributor to coal char strength, the properties and structure of colloids determine the ability of coal to bind into coke, significantly impacting the coking process. Currently, research on colloid properties primarily focuses on thermal stability, permeability, fluidity, and expansibility. Good thermal stability and a larger temperature interval indicate a longer residence time of the colloid under high heating conditions, allowing sufficient time for contact and interaction between coal particles, resulting in better coal cohesion. Poor colloid permeability results in closer contact between the multiphase mixture, strengthening the coal's cohesiveness. Expansibility and permeability interact in a complementary manner, with poor colloid permeability often leading to improved expansibility. Numerous studies have used maximum fluidity data to analyze and measure colloid fluidity, finding that greater colloid fluidity correlates with enhanced cohesion. Notably, all of these colloid properties are closely linked to their formation and cohesive behavior during the coking process, ultimately deriving from their structure and content.

[0004] To study the structure and content of colloids, extracting colloids has become one of the key research areas. As a multi-phase mixture, colloids exist in a temperature range of 400-500°C, making it difficult to accurately separate them into light and heavy phases using physical conditions alone. Therefore, chemical extraction methods are currently used for separation and extraction. Most methods use solution extraction to extract the liquid and solid phase compounds in the colloids separately, and the specific molecular phases in the coal are released through the electron-donating and electron-accepting abilities of the solvents, thereby analyzing the colloid structure during the coal coking process. Currently, pyridine and other extraction agents are often used, which can easily lead to incomplete extraction of the gas and liquid phases of the colloids, and the core colloid bonding phase is difficult to accurately separate and characterize.

[0005] Based on the above technical background, it is necessary to propose a method for separation, extraction and quantitative characterization of the light and heavy phases of the colloidal binding phase in coal, accurately separate and extract the light and heavy phases of the colloidal binding phase, determine the light and heavy phase components of the colloidal binding phase, and clarify the content of the colloidal binding phase, which will help to regulate the coke strength in the later stage. Summary of the Invention

[0006] The present invention aims to provide a method for separating and quantitatively characterizing the light and heavy phases of the colloidal binder in coal to address at least one of the aforementioned issues in the prior art. This method accurately separates and extracts the colloidal binder phase, identifying the light and heavy phases, which facilitates subsequent coke strength control.

[0007] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0008] According to one aspect of the present invention, a method for separating and quantitatively characterizing the light and heavy phases of a colloid-bound phase in coal is provided, the method comprising the following steps:

[0009] Step 1): Weigh at least four basic coal samples of predetermined weight;

[0010] Step 2): one of the basic coal samples is not heated, and the remaining basic coal samples are heated to 350°C, at least one target temperature, and 550°C and kept at this temperature for a predetermined time for heat treatment, and then cooled;

[0011] Step 3): uniformly mixing the unheated coal and the heat-treated coal with acetone respectively, and separating the liquid and the solid phase by suction filtration to obtain a plurality of first extracts and a first raffinate coal;

[0012] Step 4): centrifuging the first extract and taking out the supernatant, which is regarded as a light extract, wherein the light extract of the coal heated to the at least one target temperature comprises a light phase of a colloidal binding phase;

[0013] Step 5): drying and weighing the first raffinate coal, and calculating a first mass difference between the coal before and after extraction, where the first mass difference is regarded as the mass of the light extract;

[0014] Step 6): uniformly mixing each of the dried first raffinate coals with tetrahydrofuran, and separating the liquid and the solid phase by suction filtration to obtain a plurality of second extracts and second raffinate coals;

[0015] Step 7): centrifuging the second extract and taking out the supernatant, which is regarded as a heavy extract, wherein the heavy extract of the coal heated to the at least one target temperature comprises a heavy phase of a colloidal binding phase;

[0016] Step 8): drying and weighing the second raffinate coal, and calculating a second mass difference between the coal before and after extraction, where the second mass difference is regarded as the mass of the heavy extract;

[0017] Step 9): performing GC-MS analysis on the light extract of the light phase containing the colloid binding phase obtained in step 4) of the base coal sample heated to at least one target temperature and the light extracts obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350° C. and 550° C., and determining the composition of the light phase of the colloid binding phase and its mass percentage in the light extract based on the GC-MS analysis of the different coal samples; and performing GC-MS analysis on the heavy extract of the heavy phase containing the colloid binding phase obtained in step 7) of the base coal sample heated to at least one target temperature and the heavy extracts obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350° C. and 550° C., and determining the composition of the heavy phase of the colloid binding phase and its mass percentage in the heavy extract based on the GC-MS analysis of the different coal samples;

[0018] Step 10): Multiply the mass percentage of the light phase of the colloidal binding phase determined in step 9) corresponding to the basic coal sample heated to at least one target temperature by the mass of the corresponding light extract determined in step 5) to obtain the mass of the light phase of the colloidal binding phase of the coal at the target temperature, and multiply the mass percentage of the heavy phase of the colloidal binding phase determined in step 9) corresponding to the basic coal sample heated to at least one target temperature by the mass of the corresponding heavy extract determined in step 8) to obtain the mass of the heavy phase of the colloidal binding phase of the coal at the target temperature.

[0019] According to an embodiment of the present invention, the at least one target temperature includes a plurality of temperatures between 350°C and 550°C.

[0020] According to an embodiment of the present invention, the at least one target temperature is 400°C, 425°C, 450°C, 475°C and 500°C.

[0021] According to one embodiment of the present invention, the heat treatment in step 2) includes placing the basic coal sample in a reaction tank, heating it to a set target temperature at a heating rate of 10°C / min under a nitrogen atmosphere and keeping it warm for 1 hour, taking out the reaction tank, cooling it with nitrogen to a temperature less than 100°C, and taking out the coal.

[0022] According to one embodiment of the present invention, in step 3), the weight-to-volume ratio of coal to acetone is 1:10, and the mixture is heated in a water bath at 40-60° C. for 1-2 hours.

[0023] According to one embodiment of the present invention, in step 6), the weight-to-volume ratio of the first raffinate coal to tetrahydrofuran is 1:10, and the mixture is heated in a water bath at 50-70° C. for 1-2 hours.

[0024] According to one embodiment of the present invention, the centrifugal speed in step 4) and step 7) is 3000-4000 r / min, and the centrifugal time is 2-5 min.

[0025] According to one embodiment of the present invention, the basic coal sample is dried before the heat treatment in step 2).

[0026] According to one embodiment of the present invention, the drying temperature in step 5) and step 8) is 80-110°C.

[0027] According to one embodiment of the present invention, the basic coal sample is selected from coking coal with a particle size of 70-100 mesh.

[0028] The present invention provides a method for separating, extracting, and quantitatively characterizing the light and heavy phases of the colloid binding phase in coal. The method uses acetone and tetrahydrofuran gradient solvent extraction to obtain liquid and solid phase compounds in the colloid, and then clarifies the components of the colloid binding phase through a differential method. At the same time, the colloid binding phase components are multiplied by the corresponding light and heavy phase mass ratios to obtain the light and heavy phase contents of the colloid binding phase. This solves the problem of difficulty in accurately qualitatively and quantitatively measuring the colloid components, facilitates precise coking coal blending in the later stage, and improves the quality of coke. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 The flowchart of the method for separating the light and heavy phases of the colloid binding phase in coal and for quantitative characterization according to the present invention is exemplarily shown. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] As the primary contributor to coal char strength, the properties and structure of the colloid determine the coal's ability to bond and form coke, significantly impacting the coking process. During coal pyrolysis, temperatures below 300°C (143°F) occur in the drying and desorption phase. During this phase, the coal dehydrates and releases gases such as carbon dioxide, carbon monoxide, and nitrogen adsorbed within its capillary pores. During this process, the coal's appearance remains unchanged. At temperatures between 300°C and 450°C (143°F), the coal rapidly decomposes and softens, producing large amounts of pyrolysis gases (such as methane and other hydrocarbons) and tar. At temperatures between 450°C and 550°C (143°F), the colloid decomposes, condenses, and solidifies into semi-coke. At temperatures above 550°C (143°F), the semi-coke decomposes and condenses, ultimately transforming into coke with a certain strength and size. Coal begins to decompose and soften at temperatures around 300°C and 450°C, continuously releasing pyrolysis gases and tar, gradually forming a tar film containing bubbles on the surface of the coal particles. As pyrolysis gases and tar continue to form, the tar film expands and flows, causing the tar films of individual coal particles to converge, forming a viscous mixture of gas, liquid, and solid (the remnants of coal particles that have not yet completely melted and decomposed). This three-phase mixture is called a "colloid." Determining the light and heavy phase components of the colloid binder and clarifying its content will help control the coke strength later.

[0033] Therefore, the present invention provides a method for separating and quantitatively characterizing the light and heavy phases of the colloid binding phase in coal. Figure 1 The method of the present invention is introduced in detail.

[0034] The method generally includes:

[0035] Step S1: Weigh at least four basic coal samples of predetermined weight;

[0036] Step S2: one of the basic coal samples is not heated, and the remaining basic coal samples are heated to 350°C, at least one target temperature, and 550°C respectively and kept at these temperatures for a predetermined time for heat treatment, and then cooled;

[0037] Step S3: uniformly mixing the unheated coal and the heat-treated coal with acetone respectively, and separating the liquid and the solid phase by suction filtration to obtain a plurality of first extracts and a first raffinate coal;

[0038] Step S4: centrifuging the first extract and taking out the supernatant, which is regarded as a light extract, wherein the light extract of the coal heated to at least one target temperature comprises a light phase of a colloidal binding phase;

[0039] Step S5: drying and weighing the first raffinate coal, and calculating a first mass difference between the coal before and after extraction, where the first mass difference is regarded as the mass of the light extract;

[0040] Step S6: uniformly mixing the dried first raffinate coals with tetrahydrofuran, and separating the liquid and the solid phase by filtration to obtain a plurality of second extracts and second raffinate coals;

[0041] Step S7: centrifuging the second extract and taking out the supernatant, which is regarded as a heavy extract, wherein the heavy extract of the coal heated to at least one target temperature comprises a heavy phase of a colloidal binding phase;

[0042] Step S8: drying and weighing the second raffinate coal, and calculating a second mass difference between the coal before and after extraction, where the second mass difference is regarded as the mass of the heavy extract;

[0043] Step S9: performing GC-MS analysis on the light extract of the light phase containing the colloid binding phase obtained from the base coal sample heated to at least one target temperature in step S4 and the light extracts obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350° C. and 550° C., and determining the composition of the light phase of the colloid binding phase and its mass percentage in the light extract based on the GC-MS analysis of the different coal samples; and performing GC-MS analysis on the heavy extract of the heavy phase containing the colloid binding phase obtained from the base coal sample heated to at least one target temperature in step S7 and the heavy extracts obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350° C. and 550° C., and determining the composition of the heavy phase of the colloid binding phase and its mass percentage in the heavy extract based on the GC-MS analysis of the different coal samples;

[0044] Step S10: Multiply the mass percentage of the light phase of the colloidal binding phase determined in step S9 corresponding to the basic coal sample heated to at least one target temperature by the mass of the corresponding light extract determined in step S5 to obtain the mass of the light phase of the colloidal binding phase of the coal at the target temperature, and multiply the mass percentage of the heavy phase of the colloidal binding phase determined in step S9 corresponding to the basic coal sample heated to at least one target temperature by the mass of the corresponding heavy extract determined in step S8 to obtain the mass of the heavy phase of the colloidal binding phase of the coal at the target temperature.

[0045] In step S1, at least four base coal samples of a predetermined weight are weighed. Before weighing the base coal samples, the target temperature corresponding to the colloid to be analyzed is determined. The number of base coal samples required is determined based on the number of target temperatures. Multiple temperatures between 350°C and 550°C can be selected as target temperatures for the colloid to be analyzed. As mentioned above, colloids only form and exist when coal is heated to a certain temperature range. Therefore, the composition and content of the colloids can be studied by targeting one or more temperatures within the temperature range for colloid formation. For example, in some embodiments of the present invention, the target temperatures are set at 400°C, 425°C, 450°C, 475°C, and 500°C. In addition, unheated coal samples, coal samples heat-treated at 350°C, and coal samples heat-treated at 550°C are used as comparison samples for analysis to determine the composition and content of the colloids. Therefore, when only one target temperature is selected, at least four base coal samples are required. However, the number of target temperatures is too small to allow for observation and comparison of coal composition changes during pyrolysis. Therefore, in some embodiments, the present invention selects five temperatures: 400°C, 425°C, 450°C, 475°C, and 500°C. Accordingly, eight base coal samples are weighed. The base coal sample can be selected from a coking coal with a particle size of 70-100 mesh.

[0046] In step S2, one of the basic coal samples is not heated, and the remaining multiple basic coal samples are heated to 350°C, at least one target temperature, and 550°C respectively and kept warm for a predetermined time for heat treatment, and then cooled. Specifically, for coal that needs heat treatment, the basic coal sample can be placed in a reaction tank and heated to the set temperature (for example, 350, 400, 425, 450, 475, 500, 550°C) at a heating rate of 10°C / min under a nitrogen atmosphere and kept warm for 1 hour. The reaction tank is taken out and cooled with nitrogen to a temperature less than 100°C, and the coal is taken out. Among them, the basic coal sample is dried before heat treatment. The coal sample can be placed in an oven and dried at 110°C for 2 hours.

[0047] In step S3, the unheated coal and the heat-treated coal are each mixed with acetone, and the liquid and solid phases are separated by filtration to obtain multiple first extracts and first raffinate coal. Specifically, each group of coal is mixed with acetone at a weight-to-volume ratio of 1:10, placed in a 250ml three-necked flask, and heated in a water bath at 40-60°C for 1-2 hours. The liquid and solid phases are then separated using a suction filtration funnel.

[0048] In step S4, the first extract is centrifuged, and the supernatant is taken out and regarded as a light extract, wherein the light extract of the coal heated to at least one target temperature contains a light phase of a colloidal binding phase. The small molecule light extract in the coal is extracted by acetone. The separated liquid phase can be placed in a centrifuge and centrifuged at a speed of 3500r / min for about 3 minutes to remove the supernatant. For coal samples heated to a temperature at which a colloid is formed, the light extract contains a light phase of a colloidal binding phase and also contains some other non-colloidal substances. The light extract is separated for subsequent analysis of its composition and the content of each component using GC-MS.

[0049] In step S5, the first raffinate coal is dried and weighed, and a first mass difference between the coal before and after extraction is calculated. This first mass difference is considered the mass of the light extract. The mass of the light extract is used in subsequent calculations. The separated solid phase can be dried in an oven at 110°C for 1 hour and then weighed.

[0050] In step S6, each of the dried first raffinate coals is uniformly mixed with tetrahydrofuran, and the liquid and solid phases are separated by filtration to obtain multiple second extracts and second raffinate coals. Specifically, the dried sample and tetrahydrofuran are uniformly mixed at a ratio of 1:10 between sample mass and solvent volume, placed in a 250 mL three-necked flask, heated in a water bath at 50-70°C for 1-2 hours, and then the liquid and solid phases are separated using a suction filtration funnel.

[0051] In step S7, the second extract is centrifuged, and the supernatant is removed as the heavy extract. The heavy extract of coal heated to at least one target temperature contains the heavy phase of the colloidal binder. Specifically, the separated liquid phase is placed in a centrifuge and centrifuged at 3500 rpm for approximately 3 minutes. The supernatant is removed as the heavy extract. For coal samples heated to a temperature that forms a colloid, the heavy extract contains the heavy phase of the colloidal binder and also contains some non-colloidal substances. The heavy extract is separated for subsequent GC-MS analysis of its composition and component content.

[0052] In step S8, the second raffinate coal is dried and weighed, and a second mass difference between the coal before and after extraction is calculated. This second mass difference is considered the mass of the heavy extract. Specifically, the separated solid phase is oven-dried at 110°C for 1 hour and weighed. The difference between the coal solid samples before and after extraction is defined as the mass of the heavy extract.

[0053] In step S9, the light extract of the light phase containing the colloid binding phase obtained by the base coal sample heated to at least one target temperature in step S4 and the light extract obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350°C and 550°C are subjected to GC-MS analysis, and the composition of the light phase of the colloid binding phase and its mass percentage in the light extract are determined based on the GC-MS analysis of different coal samples. In addition, the heavy extract of the heavy phase containing the colloid binding phase obtained by the base coal sample heated to at least one target temperature in step S7 and the heavy extract obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350°C and 550°C are subjected to GC-MS analysis, and the composition of the heavy phase of the colloid binding phase and its mass percentage in the heavy extract are determined based on the GC-MS analysis of different coal samples.

[0054] In step S10, the mass percentage of the light phase of the colloidal binding phase determined in step S9 is multiplied by the mass of the corresponding light extract determined in step S5 to obtain the mass of the light phase of the colloidal binding phase of the coal at the target temperature, and the mass percentage of the heavy phase of the colloidal binding phase determined in step S9 is multiplied by the mass of the corresponding heavy extract determined in step S8 to obtain the mass of the heavy phase of the colloidal binding phase of the coal at the target temperature.

[0055] The following are specific examples of the method for separation, extraction, and quantitative characterization of the light and heavy phases of the colloid binding phase in coal according to the present invention. Unless otherwise specified, the raw materials, equipment, and consumables used in the following examples can be obtained through conventional commercial means.

[0056] For the parts involving numerical ranges, those skilled in the art can select any value within the numerical range defined by the present invention according to actual needs, and are not limited to the numerical values ​​listed in the specific embodiments.

[0057] Example 1

[0058] A method for separating, extracting, and quantitatively characterizing the light and heavy phases of a colloid-bound phase in coal comprises the following steps:

[0059] 1) Select 8 portions of coking coal 1 as basic coal samples, each weighing 50 g and numbered 1-8. Place coal samples 2-8 in an oven and dry at 110°C for 2 h. Place basic coal samples numbered 2-8 (particle size 70-100 mesh) in a reaction tank and heat to target temperatures (350, 400, 425, 450, 475, 500, and 550°C) at a heating rate of 10°C / min under a nitrogen atmosphere. Keep warm for 1 h, remove the reaction tank, cool it with nitrogen to a temperature less than 100°C, and remove the sample.

[0060] 2) Weigh 10 g of each of the coal sample No. 1 and the heat-treated coal samples No. 2-8, add 100 mL of acetone and place in a 250 mL three-necked flask, heat in a 50°C water bath for 2 h, and then use a suction filtration funnel to separate the liquid and solid phases, which are recorded as liquid phases LY1-LY8 and solid phases SY1-SY8;

[0061] 3) Place the separated liquid phases LY1-LY8 in a centrifuge and centrifuge at 3500 rpm for approximately 3 minutes, then remove the supernatant QY1-QY8;

[0062] 4) The separated solid phases SY1-SY8 were dried in an oven at 110°C for 1 hour and weighed. The difference between the coal solid samples 1-8 before and after extraction was defined as the mass of the light extract MQ1-MQ8;

[0063] 5) The dried solid phases SY1-SY8 were evenly mixed with 100 mL of tetrahydrofuran and placed in a 250 mL three-necked flask. The mixture was heated in a 50°C water bath for 2 h. The liquid and solid phases were then separated using a suction filtration funnel and recorded as liquid phases LE1-LE8 and solid phases SE1-SE8.

[0064] 6) Place the separated liquid phases LE1-LE8 in a centrifuge and centrifuge at 3500 rpm for about 3 minutes, and remove the supernatant QE1-QE8;

[0065] 7) The separated solid phases SE1-SE8 were dried in an oven at 110°C for 1 hour and weighed. The difference between the coal solid samples before and after extraction was defined as the mass of the heavy extracts MZ1-MZ8;

[0066] 8) The light extracts QY3-QY7 of coal samples heat-treated at 400, 425, 450, 475 and 500°C were analyzed by GC-MS with the light extracts QY1, QY2 and QY8 of coal samples heat-treated at 350 and 550°C, and then compared. The obtained difference phase was the colloidal light phase. The components of the light phase and their mass percentage in the light extract were determined based on the GC-MS comparison results. Correspondingly, the heavy extracts QE3-QE7 of coal samples heat-treated at 400, 425, 450, 475 and 500°C were analyzed by GC-MS with the light extracts QE1, QE2 and QE8 of coal samples heat-treated at 350 and 550°C, and then compared. The obtained difference phase was the colloidal heavy phase. The components of the heavy phase and its mass percentage in the heavy extract were determined based on the GC-MS comparison results.

[0067] 9) Multiply the obtained colloid light and heavy phases (percentage) by the mass of the light extract MQ3-MQ7 and the mass of the heavy extract MZ3-MZ7, respectively, to obtain the mass of the light and heavy phases of the colloid binding phase.

[0068] The masses of the light and heavy phases of the colloid obtained from coking coal 1 are shown in Table 1.

[0069] Table 1 Colloidal binder phase content at various temperatures of coking coals 3-7 (g, content in 10g coal)

[0070] 400 425 450 475 500 Colloidal bonding phase light phase 0.12 0.14 0.17 0.07 0.06 Colloidal binder phase 0.03 0.06 0.39 0.06 0.01

[0071] Note: 400 indicates the content of colloidal binder phase in coking coal when the heat treatment temperature is 400℃.

[0072] Example 2

[0073] A method for separating, extracting, and quantitatively characterizing the light and heavy phases of a colloid-bound phase in coal comprises the following steps:

[0074] 1) Select 8 portions of coking coal 2 as basic coal samples, each weighing 50 g and numbered 1-8. Place coal samples 2-8 in an oven and dry at 110°C for 2 h. Place basic coal samples numbered 2-8 (particle size 80-100 mesh) in a reaction tank and heat to target temperatures (350, 400, 425, 450, 475, 500, and 550°C) at a heating rate of 10°C / min under a nitrogen atmosphere. Keep warm for 1 h, remove the reaction tank, cool it to less than 100°C with nitrogen, and remove the sample.

[0075] 2) Weigh 10 g of each of the coal sample No. 1 and the heat-treated coal samples No. 2-8, add 100 mL of acetone and place in a 250 mL three-necked flask, heat in a 60°C water bath for 1 h, and then use a suction filtration funnel to separate the liquid and solid phases, which are recorded as liquid phases LY1-LY8 and solid phases SY1-SY8;

[0076] 3) Place the separated liquid phases LY1-LY8 in a centrifuge and centrifuge at 3000 rpm for approximately 4 minutes, then remove the supernatant QY1-QY8;

[0077] 4) The separated solid phases SY1-SY8 were dried in an oven at 110°C for 1 hour and weighed. The difference between the coal solid samples 1-8 before and after extraction was defined as the mass of the light extract MQ1-MQ8;

[0078] 5) The dried solid phases SY1-SY8 were evenly mixed with 100 mL of tetrahydrofuran and placed in a 250 mL three-necked flask. The mixture was heated in a 70°C water bath for 1 h. The liquid and solid phases were then separated using a suction filtration funnel and recorded as liquid phases LE1-LE8 and solid phases SE1-SE8.

[0079] 6) Place the separated liquid phases LE1-LE8 in a centrifuge and centrifuge at 3500 rpm for approximately 4 minutes, and remove the supernatant QE1-QE8;

[0080] 7) The separated solid phases SE1-SE8 were dried in an oven at 110°C for 1 hour and weighed. The difference between the coal solid samples before and after extraction was defined as the mass of the heavy extracts MZ1-MZ8;

[0081] 8) The light extracts QY3-QY7 of coal samples heat-treated at 400, 425, 450, 475 and 500°C were analyzed by GC-MS with the light extracts QY1, QY2 and QY8 of coal samples heat-treated at 350 and 550°C, and then compared. The obtained difference phase was the colloidal light phase. The components of the light phase and their mass percentage in the light extract were determined based on the GC-MS comparison results. Correspondingly, the heavy extracts QE3-QE7 of coal samples heat-treated at 400, 425, 450, 475 and 500°C were analyzed by GC-MS with the light extracts QE1, QE2 and QE8 of coal samples heat-treated at 350 and 550°C, and then compared. The obtained difference phase was the colloidal heavy phase. The components of the heavy phase and its mass percentage in the heavy extract were determined based on the GC-MS comparison results.

[0082] 9) Multiply the obtained colloid light and heavy phases (percentage) by the mass of the light extract MQ3-MQ7 and the mass of the heavy extract MZ3-MZ7, respectively, to obtain the mass of the light and heavy phases of the colloid binding phase.

[0083] The specific masses of the light and heavy phases of the colloid obtained from coking coal 2 are shown in Table 2.

[0084] Table 2 Colloidal binder phase content of coking coal samples 3-7 at various temperatures (g, content in 10g coal)

[0085] 400 425 450 475 500 Colloidal bonding phase light phase 0 0 0.03 0.07 0.01 Colloidal binder phase 0 0 0.09 0.15 0.07

[0086] Note: 400 indicates the content of colloidal binder phase in coking coal when the heat treatment temperature is 400℃.

[0087] Example 3

[0088] A method for separating, extracting, and quantitatively characterizing the light and heavy phases of a colloid-bound phase in coal comprises the following steps:

[0089] 1) Select 8 portions of the third type of coking coal as basic coal samples, each weighing 50 g and numbered 1-8. Place coal samples 2-8 in an oven and dry at 110°C for 2 h. Place basic coal samples numbered 2-8 (particle size 70-100 mesh) in a reaction tank and heat to target temperatures (350, 400, 425, 450, 475, 500, and 550°C) at a heating rate of 10°C / min under a nitrogen atmosphere. Keep warm for 1 h, remove the reaction tank, cool it with nitrogen to a temperature less than 100°C, and remove the sample.

[0090] 2) Weigh 10 g of each of the coal sample No. 1 and the heat-treated coal samples No. 2-8, add 100 mL of acetone and place in a 250 mL three-necked flask, heat in a 60°C water bath for 1.5 h, and then use a suction filtration funnel to separate the liquid and solid phases, which are recorded as liquid phases LY1-LY8 and solid phases SY1-SY8;

[0091] 3) Place the separated liquid phases LY1-LY8 in a centrifuge and centrifuge at 4000 rpm for approximately 3 minutes, then remove the supernatant QY1-QY8;

[0092] 4) The separated solid phases SY1-SY8 were dried in an oven at 110°C for 1 hour and weighed. The difference between the coal solid samples 1-8 before and after extraction was defined as the mass of the light extract MQ1-MQ8;

[0093] 5) The dried solid phases SY1-SY8 were evenly mixed with 100 mL of tetrahydrofuran and placed in a 250 mL three-necked flask. The mixture was heated in a 70°C water bath for 1 h. The liquid and solid phases were then separated using a suction filtration funnel and recorded as liquid phases LE1-LE8 and solid phases SE1-SE8.

[0094] 6) Place the separated liquid phases LE1-LE8 in a centrifuge and centrifuge at 3500 rpm for about 3 minutes, and remove the supernatant QE1-QE8;

[0095] 7) The separated solid phases SE1-SE8 were dried in an oven at 110°C for 1 hour and weighed. The difference between the coal solid samples before and after extraction was defined as the mass of the heavy extracts MZ1-MZ8;

[0096] 8) The light extracts QY3-QY7 of coal samples heat-treated at 400, 425, 450, 475 and 500°C were analyzed by GC-MS with the light extracts QY1, QY2 and QY8 of coal samples heat-treated at 350 and 550°C, and then compared. The obtained difference phase was the colloidal light phase. The components of the light phase and their mass percentage in the light extract were determined based on the GC-MS comparison results. Correspondingly, the heavy extracts QE3-QE7 of coal samples heat-treated at 400, 425, 450, 475 and 500°C were analyzed by GC-MS with the light extracts QE1, QE2 and QE8 of coal samples heat-treated at 350 and 550°C, and then compared. The obtained difference phase was the colloidal heavy phase. The components of the heavy phase and its mass percentage in the heavy extract were determined based on the GC-MS comparison results.

[0097] 9) Multiply the obtained colloid light and heavy phases (percentage) by the mass of the light extract MQ3-MQ7 and the mass of the heavy extract MZ3-MZ7, respectively, to obtain the mass of the light and heavy phases of the colloid binding phase.

[0098] The specific masses of the light and heavy phases of the colloid obtained from coking coal 3 are shown in Table 3.

[0099] Table 3 Colloidal binder phase content of coking coal samples 3-7 at various temperatures (g, content in 10g coal)

[0100] 400 425 450 475 500 Colloidal bonding phase light phase 0 0.02 0.04 0.12 0.01 Colloidal binder phase 0 0 0.09 0.24 0.12

[0101] Note: 400 indicates the content of colloidal binder phase in coking coal when the heat treatment temperature is 400℃.

[0102] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0103] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0104] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for separating and quantitatively characterizing the light and heavy phases of the colloid binding phase in coal, characterized in that: The following steps are involved: Step 1): Weigh at least four basic coal samples of predetermined weight; Step 2): One of the basic coal samples is not heated, one basic coal sample is heated to 350°C, and one basic coal sample is heated to 550°C. The remaining number of basic coal samples is not less than one. The number of target temperatures is determined according to the remaining number of coal samples. The target temperature is a temperature between 350°C and 550°C. Each of the remaining coal samples is heated to the corresponding target temperature, kept at the temperature for a predetermined time for heat treatment, and then cooled. Step 3): The unheated coal and the heat-treated coal are respectively mixed with acetone, and the liquid and the solid phase are separated by filtration to obtain a plurality of first extracts and a first raffinate coal; Step 4): centrifuging the first extract and taking out the supernatant, which is regarded as a light extract, wherein the light extract of the coal heated to a temperature between 350° C. and 550° C. comprises a light phase of a colloidal binding phase; Step 5): Dry and weigh the first raffinate coal, and calculate the first mass difference between the coal before and after extraction, where the first mass difference is regarded as the mass of the light extract; Step 6): uniformly mixing each of the dried first raffinate coals with tetrahydrofuran, and separating the liquid and the solid phase by filtration to obtain a plurality of second extracts and second raffinate coals; Step 7): centrifuging the second extract and taking out the supernatant, which is regarded as a heavy extract, wherein the heavy extract of the coal heated to a temperature between 350° C. and 550° C. comprises a heavy phase of a colloidal binding phase; Step 8): Dry and weigh the second raffinate coal, and calculate the second mass difference between the coal before and after extraction. The second mass difference is regarded as the mass of the heavy extract; Step 9): GC-MS analysis is performed on the light extract of the light phase containing the colloid binding phase obtained by the base coal sample heated to a temperature between 350°C and 550°C in step 4), and the light extracts obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350°C and 550°C. The composition of the light phase of the colloid binding phase and its mass percentage in the light extract are determined based on the GC-MS analysis of the different coal samples. Moreover, GC-MS analysis is performed on the heavy extract of the heavy phase containing the colloid binding phase obtained by the base coal sample heated to a temperature between 350°C and 550°C in step 7), and the heavy extracts obtained by extracting the unheated base coal sample and the coal sample heat-treated at 350°C and 550°C. The composition of the heavy phase of the colloid binding phase and its mass percentage in the heavy extract are determined based on the GC-MS analysis of the different coal samples. Step 10): Multiply the mass percentage of the light phase of the colloidal binding phase determined in step 9) corresponding to the basic coal sample heated to a temperature between 350°C and 550°C by the mass of the corresponding light extract determined in step 5) to obtain the mass of the light phase of the colloidal binding phase of the coal at a temperature between 350°C and 550°C, and multiply the mass percentage of the heavy phase of the colloidal binding phase determined in step 9) corresponding to the basic coal sample heated to a temperature between 350°C and 550°C by the mass of the corresponding heavy extract determined in step 8) to obtain the mass of the heavy phase of the colloidal binding phase of the coal at a temperature between 350°C and 550°C.

2. The method according to claim 1, characterized in that The remaining coal sample in step 2) is divided into multiple portions and heated to multiple temperatures between 350° C. and 550° C. respectively.

3. The method according to claim 2, characterized in that The remaining coal samples described in step 2) are 5 portions, which are heated to 400°C, 425°C, 450°C, 475°C and 500°C respectively.

4. The method according to claim 1, wherein The heat treatment in step 2) includes placing the basic coal sample in a reaction tank, heating it to the set target temperature at a heating rate of 10°C / min under a nitrogen atmosphere and keeping it at that temperature for 1 hour, taking out the reaction tank, cooling it with nitrogen to a temperature less than 100°C, and then taking out the coal.

5. The method according to claim 1, wherein Step 3) The weight-to-volume ratio of medium coal to acetone is 1:10, and the mixture is heated in a water bath at 40-60°C for 1-2 hours.

6. The method according to claim 1, characterized in that In step 6), the weight-to-volume ratio of the first raffinate coal to tetrahydrofuran is 1:10, and the mixture is heated in a water bath at 50-70° C. for 1-2 hours.

7. The method according to claim 1, characterized in that The centrifugal speed in step 4) and step 7) is 3000-4000 r / min, and the centrifugal time is 2-5 min.

8. The method according to claim 1, characterized in that In step 2), the base coal sample is dried before heat treatment.

9. The method according to claim 1, characterized in that The drying temperature in step 5) and step 8) is 80-110°C.

10. The method according to claim 1, characterized in that The basic coal sample is selected from coking coal with a particle size of 70-100 mesh.

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