Evaluation method and evaluation system for vitrinite enrichment in coal

Abstract

The invention discloses an evaluation method and an evaluation system for vitrinite enrichment in coal, and relates to the technical field of coal detection. The method comprises the following steps: firstly, detecting the content of macerals in a coal sample according to the provision of the national standard GB / T 15588-2013 Classification of Macerals of Bituminous Coal; then, according to the influence degree of different forms of macerals on vitrinite enrichment, different macerals are endowed with weights; and finally, products of all the macerals and the weights are added to obtain a vitrinite enrichment coefficient of the coal, the enrichment difficulty degree is judged according to the vitrinite enrichment coefficient, and the larger the value of the vitrinite enrichment coefficient is, the easier enrichment is achieved. The method can be used for objectively and accurately evaluating the enrichment difficulty degree of the vitrinite in different coal samples, is simple and convenient to operate, and can be popularized and used.

Description

Technical Field

[0001] The invention relates to the technical field of coal detection, and in particular to an evaluation method and an evaluation system for vitrinite enrichment in coal. Background Art

[0002] Vitrinite is an important microscopic component in coal. It is mainly a gelled substance with humic acid and asphaltene as the main components formed by the gelation of wood fiber tissues of higher plants. The original plant tissues that form coal undergo complex physical and chemical changes in a swamp environment with closed airflow and deep water. The vitrinite appears gray under ordinary reflected light of a polarizing microscope and dark gray under oil-immersed reflected light, with no protrusions on the surface. The vitrinite content in most coalfields in my country is between 60% and 80%. The content of vitrinite in coal has an important influence on the physical and chemical properties of coal. Vitrinite plays an important role in the conversion and utilization of coking coal, coal gasification, liquefaction, etc. Scientific research on vitrinite enrichments can provide support for the clean and efficient utilization of coal.

[0003] Conventional separation methods for coal microscopic components include: hand selection, screening, gravity separation, electrostatic separation and flotation, etc. Through the above methods, the separation effect of microscopic components is relatively obvious. In the separation process of microscopic components, sometimes two coals with the same vitrinite content have obvious differences in the effects when using the same separation method due to the different occurrence forms of microscopic components. When the vitrinite in coal exists in the form of homogeneous vitrinite, agglomerated vitrinite or matrix vitrinite, and the inertinite exists in the form of silkenite, the separation and enrichment effect of microscopic components is better; when the content of minerals, semi-silky bodies and clastic inertinite in coal is high, it is relatively unfavorable for the separation of vitrinite in coal.

[0004] Therefore, considering the above issues, it is necessary to evaluate the difficulty of separating vitrinite in different coals. Summary of the invention

[0005] The maceral components of coal are mainly composed of vitrinite, inertinite and exinite. Due to the different occurrence forms of the maceral components, the enrichment and separation effects of coal from different mining areas with the same vitrinite content will be significantly different when using the same enrichment method. Therefore, in order to objectively analyze the difficulty of vitrinite enrichment in coal, the present invention provides an evaluation method for vitrinite enrichment in coal, which more accurately evaluates the difficulty of vitrinite enrichment in different coals through the enrichment coefficient.

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

[0007] A method for evaluating vitrinite enrichment in coal, the method comprising the following steps:

[0008] S1. Detect the content of microscopic components in coal samples;

[0009] S2. According to the influence of different forms of microscopic components on the enrichment of vitrinite, weights are assigned to different microscopic components;

[0010] S3, according to formula (1), the product of the content of each microscopic component and its corresponding weight is added to obtain the vitrinite enrichment coefficient of the coal sample;

[0011] Vitrinite enrichment coefficient = structural vitrinite content*3+homogeneous vitrinite content*5+matrix vitrinite content*2+agglomerated vitrinite content*5+colloidal vitrinite content*2+detrital vitrinite content+silky vitrinite content*3-semi-silky vitrinite content*2-detrital inertinite content*5-coarse-grained vitrinite content*3-micro-grained vitrinite content*1-exo-grained vitrinite content*1-mineral content*1(1);

[0012] S4. Determine the degree of difficulty of enrichment of the vitrinite in the coal sample according to the vitrinite enrichment coefficient obtained in S3.

[0013] In the above-mentioned method for evaluating vitrinite enrichment in coal, in step S1, the content of macerals in the coal sample is detected according to the provisions of the national standard GB / T 15588-2013 "Classification of macerals of bituminous coal".

[0014] In the above-mentioned method for evaluating the enrichment of vitrinite in coal, in step S2, the types of the above-mentioned microscopic components are structural vitrinite, homogeneous vitrinite, matrix vitrinite, colloidal vitrinite, agglomerated vitrinite, fragmental vitrinite, silken body, semi-silky body, coarse grain, micron body, fragmental inertinite, exinite and minerals.

[0015] In the above-mentioned method for evaluating vitrinite enrichment in coal, in step S4, when the vitrinite enrichment coefficient is less than 0.5, it means that it is extremely difficult to enrich; when 0.5≤the vitrinite enrichment coefficient≤1, it means that it is difficult to enrich; when 1≤the vitrinite enrichment coefficient≤2, it means that it is easy to enrich; when the vitrinite enrichment coefficient is greater than 2, it means that it is extremely easy to enrich.

[0016] In the above-mentioned method for evaluating the enrichment of vitrinite in coal, structural vitrinite is vitrinite with a cellular structure; and the homogeneous vitrinite refers to unstructured vitrinite that is uniform, pure, has clear boundaries, and is distributed in stripes.

[0017] In the above-mentioned method for evaluating the enrichment of vitrinite in coal, the fibroin is mainly formed by carbonization of wood fiber cells and has the high reflectivity of plant cell structure.

[0018] In the above-mentioned method for evaluating the enrichment of vitrinite in coal, the clastic inertinite is a clastic component of the inertinite group, with a particle size of less than 30 μm; and the semi-filamentous body is in the shape of strips or lenses.

[0019] Another object of the present invention is to provide an evaluation system for vitrinite enrichment in coal, which adopts the above evaluation method.

[0020] The evaluation system comprises a detection unit, an input unit, a calculation unit and an evaluation unit.

[0021] In the above-mentioned evaluation system for vitrinite enrichment in coal, the detection unit is used to detect the content of microscopic components in the coal sample; the input unit is used to input the content of microscopic components detected by the detection unit into a computer; the calculation unit uses a computer to calculate the data obtained by the input unit and calculate the vitrinite enrichment coefficient of the coal sample; the evaluation unit is used to evaluate the difficulty of enrichment of the vitrinite in the coal sample.

[0022] The above-mentioned evaluation system for vitrinite enrichment in coal also includes a display unit, and the display unit is used to output and display the evaluation results obtained by the evaluation unit.

[0023] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0024] (1) The present invention proposes a method for evaluating the enrichment of vitrinite in coal. First, the content of the macerals in the coal sample is detected according to the provisions of the national standard GB / T15588-2013 "Classification of macerals of bituminous coal". Then, weights are assigned to different macerals according to the degree of influence of macerals of different forms on the enrichment of vitrinite. Finally, the product of the content of each maceral and the weight is added to obtain the vitrinite enrichment coefficient of the coal. The difficulty of enrichment is judged according to the vitrinite enrichment coefficient. The larger the value of the vitrinite enrichment coefficient, the easier it is to be enriched.

[0025] (2) The present invention also provides an evaluation system using the above evaluation method, including a detection unit, an input unit, a calculation unit, an evaluation unit and a display unit. Through the cooperation of each unit, the difficulty of enrichment of the vitrinite group of the coal sample can be evaluated.

[0026] In summary, the method of the present invention can objectively and accurately evaluate the difficulty of vitrinite enrichment in different coal samples. The method is simple to operate and can be promoted for use. DETAILED DESCRIPTION

[0027] The present invention proposes an evaluation method and an evaluation system for vitrinite enrichment in coal. In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is further described below in conjunction with specific embodiments.

[0028] The experimental instruments required for the determination of microscopic components in the coal sample in the present invention include: a polarizing microscope, a stage pusher, a calculator, a sample mounting mechanism, a slide, and the like.

[0029] The specific steps for determining the microscopic components are as follows: first adjust the polarizing microscope, turn on the reflected light switch, place the coal rock light sheet on the stage, use a 50x oil objective lens, adjust the focal length to make the image clear, and record the image features.

[0030] Microscopic image characteristics and determination methods:

[0031] Structural vitrinite: vitrinite with cellular structure.

[0032] Homogeneous vitrinite: Uniform, pure, clearly-bounded, and structureless vitrinite distributed in stripes.

[0033] Matrix vitrinite: Amorphous, structureless vitrinite that is cemented with other components or fragments.

[0034] Glial vitrinite: Uniform, dense, colloidal, structureless vitrinite filling the cell cavity or cracks.

[0035] Massive vitrinite: structureless vitrinite that is mostly round or oval, uniform and massive, or fills the cell cavity, and has a slightly stronger reflectivity than gelatinous vitrinite.

[0036] Detrital vitrinite: Detrital vitrinite with a particle size of less than 10 μm is mostly granular or irregular, and occasionally angular.

[0037] Silky body: It is mainly formed by the carbonization of wood fiber cells. It is a highly reflective inert body with plant cell structure. It is bright white or bright yellowish white under oil immersion reflection, with a high protrusion in the middle, with a cell structure, and is strip-shaped, lens-shaped or irregular.

[0038] Semi-vitrinite: The reflectivity is between vitrinite and inertinite, and it has a cellular structure. It is grayish white under oil immersion reflection, with a protrusion in the middle, and is strip-shaped, lens-shaped or irregular.

[0039] Coarse grains: Grayish white, white, or light yellow under oil immersion reflection, with a high protrusion in the middle and basically no cell structure.

[0040] Microsomes: Small round or quasi-round particles that appear white-gray, gray-white to yellow-white under oil immersion reflection, with a particle size generally below 1μm.

[0041] Detrital inertic body: It is the detrital component of the inertic group, with a particle size of less than 30μm and an extremely irregular shape.

[0042] Exosome: It is dark gray under oil-immersion reflected light, has low reflectivity, and emits bright yellow fluorescence under blue light excitation.

[0043] The present invention provides a method for evaluating vitrinite enrichment in coal, comprising the following steps:

[0044] Step 1: Detect the content of macerals in coal samples according to the national standard GB / T 15588-2013 "Classification of macerals of bituminous coal".

[0045] Step 2: assign weights to different microscopic components according to their influence on the enrichment of vitrinite;

[0046] Step 3: According to formula (1), the product of the content of each microscopic component and its corresponding weight is added to obtain the vitrinite enrichment coefficient of the coal sample;

[0047] Vitrinite enrichment coefficient = structural vitrinite content*3+homogeneous vitrinite content*5+matrix vitrinite content*2+agglomerated vitrinite content*5+colloidal vitrinite content*2+detrital vitrinite content+silky vitrinite content*3-semi-silky vitrinite content*2-detrital inertinite content*5-coarse-grained vitrinite content*3-micro-grained vitrinite content*1-exo-grained vitrinite content*1-mineral content*1(1);

[0048] Step 4: Determine the difficulty of enrichment of the vitrinite in the coal sample according to the vitrinite enrichment coefficient obtained in step 3. When the vitrinite enrichment coefficient is less than 0.5, it means that it is extremely difficult to enrich; when 0.5≤the vitrinite enrichment coefficient≤1, it means that it is difficult to enrich; when 1≤the vitrinite enrichment coefficient≤2, it means that it is easy to enrich; when the vitrinite enrichment coefficient is greater than 2, it means that it is extremely easy to enrich. See Table 1 for details.

[0049] Table 1 Enrichment coefficient categories

[0050] Vitrinite enrichment factor category <0.5 Very difficult to enrich 0.5-1 Difficult to enrich 1-2 Easy to enrich >2 Very easy to enrich

[0051] An evaluation system for vitrinite enrichment in coal using the above method includes a detection unit, an input unit, a calculation unit, an evaluation unit and a display unit. The detection unit is used to detect the content of microscopic components in the coal sample. For example, by setting the program of the national standard GB / T15588-2013 "Classification of Microscopic Components of Bituminous Coal" in the detection unit, the content of microscopic components in the coal sample can be detected.

[0052] The specific detection and determination methods of the microscopic components in the coal samples refer to the above-mentioned microscopic image characteristics and determination methods.

[0053] The input unit is used to input the content of the microscopic components detected by the detection unit into the computer to facilitate the next step of calculation.

[0054] The calculation unit uses a computer to calculate the data obtained from the input unit and calculates the vitrinite enrichment coefficient of the coal sample. For example, by setting the above formula in the calculation unit, the vitrinite enrichment coefficient of the coal sample can be calculated through the formula.

[0055] The evaluation unit is used to evaluate the difficulty of enrichment of the vitrinite group of the coal sample. The specific setting procedure refers to the setting of the enrichment coefficient category.

[0056] The display unit is used to output and display the evaluation results obtained by the evaluation unit. After comparison, the enrichment coefficients calculated by the evaluation unit can be displayed through the display unit as "extremely difficult to enrich", "difficult to enrich", "easy to enrich" or "extremely easy to enrich".

[0057] The present invention will be further described below in conjunction with specific embodiments.

[0058] Embodiment 1:

[0059] The coal sample in this embodiment comes from Inner Mongolia Autonomous Region, and the evaluation method of the present invention is adopted, and the specific steps are as follows:

[0060] (1) The maceral content of the coal sample was tested according to national standards. The maceral content of the coal sample is shown in Table 2.

[0061] Table 2 Microscopic components of coal sample of Example 1 (%)

[0062]

[0063] (2) Weights are assigned to different maceral components according to their influence on the enrichment of vitrinite.

[0064] (3) According to the above formula (1), the product of the content of each microscopic component and its corresponding weight is added to obtain the vitrinite enrichment coefficient of the coal sample, and the vitrinite enrichment coefficient is calculated to be 2.15.

[0065] (4) According to the corresponding enrichment coefficient category, it is concluded that the coal sample in this example belongs to the vitrinite group and is very easy to enrich.

[0066] Embodiment 2:

[0067] The coal sample in this embodiment comes from Shanxi, and the evaluation method of the present invention is adopted, and the specific steps are as follows:

[0068] (1) The maceral content of the coal sample was tested according to national standards. The maceral content of the coal sample is shown in Table 3.

[0069] Table 3 Microscopic components of coal sample of Example 2 (%)

[0070]

[0071] (2) Weights are assigned to different maceral components according to their influence on the enrichment of vitrinite.

[0072] (3) According to the above formula (1), the product of the content of each microscopic component and its corresponding weight is added to obtain the vitrinite enrichment coefficient of the coal sample, and the vitrinite enrichment coefficient is calculated to be 1.22.

[0073] (4) According to the corresponding enrichment coefficient category, it is concluded that the coal sample in this example belongs to the vitrinite group that is easy to enrich.

[0074] Embodiment 3:

[0075] The coal sample in this embodiment comes from Shendong, and the evaluation method of the present invention is adopted, and the specific steps are as follows:

[0076] (1) The maceral content of the coal sample was tested according to national standards. The maceral content of the coal sample is shown in Table 4.

[0077] Table 4 Microscopic components of coal sample of Example 3 (%)

[0078]

[0079]

[0080] (2) Weights are assigned to different maceral components according to their influence on the enrichment of vitrinite.

[0081] (3) According to the above formula (1), the product of the content of each microscopic component and its corresponding weight is added to obtain the vitrinite enrichment coefficient of the coal sample, and the vitrinite enrichment coefficient is calculated to be -0.24.

[0082] (4) According to the corresponding enrichment coefficient category, it is concluded that the coal sample in this embodiment belongs to the vitrinite group which is extremely difficult to enrich.

[0083] Embodiment 4:

[0084] The coal sample in this embodiment comes from northern Shaanxi, and the evaluation method of the present invention is adopted, and the specific steps are as follows:

[0085] (1) The maceral content of the coal sample was tested according to national standards. The maceral content of the coal sample is shown in Table 5.

[0086] Table 5 Microscopic components of coal sample of Example 4 (%)

[0087]

[0088] (2) Weights are assigned to different maceral components according to their influence on the enrichment of vitrinite.

[0089] (3) According to the above formula (1), the product of the content of each microscopic component and its corresponding weight is added to obtain the vitrinite enrichment coefficient of the coal sample, and the vitrinite enrichment coefficient is calculated to be 0.69.

[0090] (4) According to the corresponding enrichment coefficient category, it is concluded that the coal sample in this example belongs to the vitrinite group that is difficult to enrich.

[0091] In summary, the method of the present invention determines the difficulty of vitrinite enrichment in coal by assigning corresponding scores to each microscopic component to obtain the vitrinite enrichment coefficient. The larger the value of the vitrinite enrichment coefficient, the easier it is to be enriched.

[0092] Parts not described in the present invention can be implemented by those skilled in the art by referring to the existing technology.

[0093] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments should fall within the scope of protection of the claims of the present application.

Claims

1. A method for evaluating vitrinite enrichment in coal, characterized in that: The evaluation method comprises the following steps: S1. Detect the content of microscopic components in coal samples; S2. According to the influence of different forms of microscopic components on the enrichment of vitrinite, weights are assigned to different microscopic components; S3, according to formula (1), the product of the content of each microscopic component and its corresponding weight is added to obtain the vitrinite enrichment coefficient of the coal sample; Vitrinite enrichment coefficient = structural vitrinite content*3+homogeneous vitrinite content*5+matrix vitrinite content*2+agglomerated vitrinite content*5+colloidal vitrinite content*2+detrital vitrinite content+silky vitrinite content*3-semi-silky vitrinite content*2-detrital inertinite content*5-coarse-grained vitrinite content*3-micro-grained vitrinite content*1-exo-grained vitrinite content*1-mineral content*1(1); S4. Determine the degree of difficulty of enrichment of the vitrinite in the coal sample according to the vitrinite enrichment coefficient obtained in S3.

2. The method for evaluating vitrinite enrichment in coal according to claim 1, characterized in that: In step S1, the content of maceral components in the coal sample is detected according to the provisions of the national standard GB / T 15588-2013 "Classification of maceral components of bituminous coal".

3. The method for evaluating vitrinite enrichment in coal according to claim 1, characterized in that: In step S2, the types of the microscopic components are structural vitrinite, homogeneous vitrinite, matrix vitrinite, colloidal vitrinite, agglomerated vitrinite, fragmentary vitrinite, silken body, semi-silky body, coarse grain, micron body, fragmentary inertinite, exinite and mineral.

4. The method for evaluating vitrinite enrichment in coal according to claim 1, characterized in that: In step S4, when the vitrinite enrichment coefficient is less than 0.5, it means that it is extremely difficult to enrich; when the vitrinite enrichment coefficient is less than 0.5, it means that it is difficult to enrich; When 1≤when the vitrinite enrichment coefficient≤2, it means it is easy to enrich; when the vitrinite enrichment coefficient>2, it means it is very easy to enrich.

5. The method for evaluating vitrinite enrichment in coal according to claim 3, characterized in that: The structural vitrinite is a vitrinite with a cellular structure; the homogeneous vitrinite refers to a structureless vitrinite that is uniform, pure, has clear boundaries, and is distributed in stripes.

6. The method for evaluating vitrinite enrichment in coal according to claim 3, characterized in that: The silk body is mainly formed by carbonization of wood fiber cells and has the high reflectivity of plant cell structure.

7. The method for evaluating vitrinite enrichment in coal according to claim 3, characterized in that: The clastic ineritic body is a clastic component of the ineritic group, and the particle size is less than 30 μm; the semi-filamentous body is in the shape of strips or lenses.

8. An evaluation system for vitrinite enrichment in coal, characterized by: It adopts the evaluation method described in any one of claims 1 to 7; The evaluation system comprises a detection unit, an input unit, a calculation unit and an evaluation unit.

9. The evaluation system for vitrinite enrichment in coal according to claim 8, characterized in that: The detection unit is used to detect the content of microscopic components in the coal sample; the input unit is used to input the content of microscopic components detected by the detection unit into the computer; the calculation unit uses a computer to calculate the data obtained by the input unit and calculate the vitrinite enrichment coefficient of the coal sample; the evaluation unit is used to evaluate the difficulty of enrichment of the vitrinite of the coal sample.

10. The evaluation system for vitrinite enrichment in coal according to claim 8, characterized in that: It also includes a display unit, which is used to output and display the evaluation results obtained by the evaluation unit.

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