Evaluation method of relative content and dissociation degree of coal rock components based on density distribution

Abstract

The present invention discloses a method for evaluating the relative content and dissociation degree of coal rock components based on density distribution, comprising the following steps: separating representative test sample A and test sample B from the test coal sample; fully dissociating different microscopic components in the test sample A, and using an isopycnic gradient centrifugation method to sort the dissociated test sample A and test sample B for multiple times, and then drawing density distribution diagrams of the test sample A and the test sample B respectively; then obtaining the dissociation spectrum of the test sample A and the test sample B by a peak fitting method, and calculating the independent area and overlapping area ratio of the distribution peaks of different microscopic components in the test sample A and the test sample B in turn; and then calculating the relative content and dissociation degree of different microscopic components in the coal rock. The present invention obtains the density distribution characteristics of the coal sample by isopycnic gradient centrifugation, thereby understanding the dissociation law of the microscopic components of the coal rock, and providing theoretical guidance for the crushing and sorting of the microscopic components of the coal rock.

Description

Technical Field

[0001] The invention belongs to the technical field of coal processing, and in particular relates to a method for evaluating the relative content and dissociation degree of coal rock components based on density distribution. Background Art

[0002] There are great differences in the process performance of different coal rock micro-components. Vitrinite and exinite have the advantages of high cohesiveness, reactivity and oil conversion rate in the coal conversion process, and are high-quality raw materials in the fields of coal coking, pyrolysis, liquefaction and preparation of coal-based composite materials; while the inertinite is extremely weak or inactive, and its high content will lead to reduced coal liquefaction performance and reactivity, poor cohesiveness and slurrying performance, and can be used as raw materials or fuels for the preparation of carbon materials such as graphite and activated carbon. Therefore, through effective separation and enrichment of coal rock components, the qualitative transformation and utilization of different coal rock components can be achieved, which will effectively promote the green and efficient utilization of high inertinite coal, and bring about a qualitative transformation of my country's coal processing and utilization and coal chemical industry.

[0003] The full dissociation of coal rock microscopic components is the premise for the effective separation of different components, and the determination of coal rock microscopic components is the main means to evaluate the enrichment degree of coal rock microscopic components and the technical guarantee for the high-quality separation of coal rock microscopic components. However, most coal can only achieve a good dissociation effect when it is crushed to less than 10μm. Therefore, the quantitative determination of different components in fine particles has become the focus and difficulty of future coal rock work. At present, the specific method for determining the content of coal rock microscopic components mainly relies on the national standard "Coal Microscopic Component Grouping and Mineral Determination Method" (GB / T8899-2013). However, this method requires that the sample size must be less than 1mm in the pulverized coal optical film used for quantitative statistics of coal rock microscopic components, and at the same time, the material with a diameter less than 0.1mm shall not exceed 10%. When the content of fine particles is high, it cannot be detected; in addition, the test process of this method is time-consuming and inefficient, and is easily affected by the tester's operation and his ability to identify coal rock microscopic components. Therefore, there is an urgent need to develop a method for determining the microscopic components of coal and rock that is time-saving, efficient, accurate, and not affected by the tester's operation. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a method for evaluating the relative content and dissociation degree of coal rock components based on density distribution. The density distribution characteristics of coal samples are obtained by isopycnic gradient centrifugation, so as to understand the dissociation laws of coal rock microscopic components and provide theoretical guidance for the crushing and sorting of coal rock microscopic components.

[0005] To achieve the above object, the technical solution adopted by the present invention is to provide a method for evaluating the relative content and dissociation degree of coal rock components based on density distribution, comprising the following steps:

[0006] Step 1: Separate representative test sample A and test sample B from the test coal sample;

[0007] Step 2: fully dissociate the different microscopic components in the sample A to be tested, and use an isopycnic gradient centrifugation method to sort the dissociated sample A for multiple times, and calculate the average value of the mass fraction of each density level, and then draw a density distribution map of the sample A to be tested;

[0008] Step 3: sorting the sample B for multiple times by isopycnic gradient centrifugation, and calculating the average value of the mass fraction of each density level, and then drawing a density distribution diagram of the sample B for multiple times;

[0009] Step 4: According to the density distribution diagram of the sample A to be tested in the step 2, a dissociation spectrum of the sample A to be tested is obtained by a peak fitting method, and the independent area and overlapping area ratios of the distribution peaks of different microscopic components in the sample A to be tested are calculated in sequence; According to the density distribution diagram of the sample B to be tested in the step 3, a dissociation spectrum of the sample B to be tested is obtained by a peak fitting method, and the independent area and overlapping area ratios of the distribution peaks of different microscopic components in the sample B to be tested are calculated in sequence;

[0010] Step 5: Calculate the relative contents of different microscopic components in the coal rock according to the independent area ratios and overlapping area ratios of the distribution peaks of different microscopic components in the sample A to be tested calculated in step 4;

[0011] Step six: Calculate the degree of dissociation of different microscopic components in the coal rock based on the independent area ratio and overlapping area ratio of the distribution peaks of different microscopic components in the sample A to be tested calculated in the step four, and the independent area ratio and overlapping area ratio of the distribution peaks of different microscopic components in the sample B to be tested calculated.

[0012] Furthermore, the sufficient dissociation in the step 2 refers to crushing the sample A to be tested by a disc crusher so that the mass proportion of the material with a particle diameter less than 10 μm in the sample A to be tested is greater than or equal to 90%.

[0013] Furthermore, the density gradient of the separation medium in the isopycnic gradient centrifugation method in step 2 and step 3 is 0.01 g / cm 3 or 0.02g / cm 3 .

[0014] Furthermore, the number of sorting in step 2 and step 3 is at least three times.

[0015] Furthermore, the independent area ratio of the distribution peaks of different microscopic components in the sample A to be tested in step 4 refers to the ratio of the distribution peak area of ​​the exinite group to the total area. l , the ratio of the vitrinite distribution peak area to the total area Av , the ratio of the inerting group distribution peak area to the total area A i The overlapping area ratio of different microscopic components in the sample A to be tested refers to the ratio of the overlapping area of ​​the exinite and the vitrinite to the total area. l-v , the ratio of the overlapping area of ​​vitrinite and inertinite to the total area A v-i , the total area refers to the sum of the areas of the distribution peaks of exinite, vitrinite and inertinite.

[0016] Furthermore, the independent area ratio of the distribution peaks of different microscopic components in the sample B to be tested in step 4 refers to the ratio of the distribution peak area of ​​the exinite group to the total area. l , the ratio of the vitrinite distribution peak area to the total area B v , the ratio of the inerting group distribution peak area to the total area B i The overlapping area ratio of different microscopic components in the sample B to be tested refers to the ratio of the overlapping area of ​​the exinite and the vitrinite to the total area. l-v , the ratio of the overlapping area of ​​vitrinite and inertinite to the total area B v-i , the total area refers to the sum of the areas of the distribution peaks of exinite, vitrinite and inertinite.

[0017] Furthermore, the relative content M of the exinite in step 5 is l Expressed as: M l =(A l +0.5A l-v )×100%; relative content of vitrinite M v Expressed as: M v =(0.5A l-v +A v +0.5A v-i )×100%; Relative content of inert group M i Expressed as: M i =(0.5A v-i +A i )×100%.

[0018] Furthermore, the degree of dissociation of the exin group in step 6 is L l It is expressed as: The dissociation degree of vitrinite L v It is expressed as: The dissociation degree of the inert group L i It is expressed as:

[0019] Furthermore, the dissociation degree of the coal rock microscopic components refers to the relative dissociation degree when the coal crushing products are relatively fully dissociated.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The present invention is not limited by the type and quality of coal. According to the density difference between different microscopic components of coal rock, the density distribution characteristics of coal samples are obtained by isopycnic gradient centrifugation at narrow density levels, and the dissociation spectrum of coal rock is obtained by peak fitting method, thereby realizing the evaluation of the degree of separation and relative content of microscopic components of fine-grained coal, and providing technical guarantee for high-quality sorting of microscopic components of coal rock in actual industrial production.

[0022] 2. The present invention is simple to operate and easy to master. The isopycnic gradient centrifugation method and multi-peak fitting method adopted have low requirements on the operator. Different operators have little influence on the experimental results, which can effectively improve work efficiency and can be mastered and used by scientific research, technology and management personnel related to mineral processing engineering.

[0023] 3. The present invention is not affected by the experience of the tester, the data obtained is intuitive and accurate, the test results can be repeated and traced, and the errors caused by accidental factors and human factors can be effectively avoided, thereby improving the accuracy of the experimental results.

[0024] The present invention is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flowchart of the steps of the present invention.

[0026] Figure 2 This is the density distribution diagram of the sample A to be tested after it is fully dissociated in the present invention.

[0027] Figure 3 It is the density distribution diagram of the sample B to be tested in the present invention.

[0028] Figure 4 This is the dissociation spectrum of the test sample A after it is fully dissociated.

[0029] Figure 5 It is the dissociation spectrum of the sample B to be tested in the present invention. DETAILED DESCRIPTION

[0030] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] Generally, among the microscopic components of the same coal sample, the density of the exinite is the lowest, followed by the vitrinite, and the density of the inertinite is the highest. Therefore, the present invention provides a method for evaluating the content and dissociation degree of coal rock microscopic components based on density distribution. According to the density difference between the microscopic components of coal rock, the density distribution characteristics of the coal sample are obtained by isopycnic gradient centrifugation with narrow density levels, so as to understand the dissociation law of the microscopic components of coal rock, and provide theoretical guidance for the crushing and sorting of the microscopic components of coal rock.

[0033] The density gradient of the separation medium in the isopycnic gradient centrifugation separation method adopted by the present invention is 0.01 g / cm 3 or 0.02g / cm 3 , that is, the density difference between each density level of the separation medium is 0.01g / cm 3 or 0.02g / cm 3 Compared with the normal floating and sinking experiment using 0.1g / cm 3 or 0.05g / cm 3 It is a density gradient. The difference between each density level in the present invention is smaller, so it is called a narrow density level. The isopycnic gradient centrifugation method of narrow density levels can accurately reflect the density composition and distribution state of different microscopic components, provide a basis for evaluating the relative content and dissociation degree of different microscopic components, and improve the accuracy of the evaluation results.

[0034] like Figure 1-5 As shown, the present invention provides a method for evaluating the relative content and dissociation degree of coal rock components based on density distribution, comprising the following steps:

[0035] Step 1: Separate representative test samples A and B from the test coal sample, wherein the test coal sample is a dissociated sample to be evaluated, and the representativeness means that the separated test samples A and B both include various main components of the coal sample and can fully reflect the situation of the coal sample;

[0036] Step 2: Fully dissociate the different microscopic components in the sample A to be tested, and repeat the separation of the dissociated sample A for at least three times by isopycnic gradient centrifugation to avoid experimental errors caused by the operator, improve the accuracy of the experimental results, eliminate abnormal data during the test, and calculate the average mass fraction of the products at each density level to obtain the data in Table 1 below, and then draw the density distribution map of the sample A to be tested by the origin software, that is, Figure 2As shown. Wherein, the sufficient dissociation means that the sample A to be tested is crushed by a disc crusher so that the mass proportion of the material with a particle diameter less than 10 μm in the sample A to be tested is greater than or equal to 90%. Considering the fine particle size of the sample, the isopycnic gradient centrifugation method uses three organic heavy liquids, benzene, carbon tetrachloride and bromoform, to mix and prepare the required density, and the density gradient is preferably 0.02 g / cm 3 .

[0037] Table 1 Narrow density gradient centrifugation results of sample A

[0038]

[0039]

[0040] Step 3: Repeat the separation of the sample B at least three times by isopycnic gradient centrifugation to avoid experimental errors caused by the operator, improve the accuracy of the experimental results, eliminate abnormal data during the test, and calculate the average mass fraction of each density level product to obtain the data in Table 2 below, and then draw a density distribution map of the sample B by using the origin software, as shown in Table 2. Figure 3 Considering that the sample particle size is relatively fine, the isopycnic gradient centrifugation method uses three organic heavy liquids, benzene, carbon tetrachloride and bromoform, to mix and prepare the required density, and the density gradient is preferably 0.02 g / cm 3 ;

[0041] Table 2 Narrow density gradient centrifugation results of sample B

[0042]

[0043]

[0044] Step 4: According to the density distribution diagram of the sample A in step 2, the dissociation spectrum of the sample A is obtained by the peak fitting method in the origin software, that is, Figure 4 As shown, the independent area and overlapping area ratio of the distribution peaks of different microscopic components in the sample A to be tested are calculated in turn; according to the density distribution diagram of the sample B to be tested in step three, the dissociation spectrum of the sample B to be tested is obtained by the peak fitting method in the origin software, that is, Figure 5 As shown, the independent area and overlapping area ratio of the distribution peaks of different microscopic components in the sample B to be tested are calculated in turn;

[0045] Among them, the independent area ratio of the distribution peaks of different microscopic components in the sample A to be tested refers to the ratio of the distribution peak area of ​​the exinite group to the total area. l , A l The ratio of the vitrinite distribution peak area to the total area is 6.35%.v , A v The ratio of the inert group distribution peak area to the total area is 48.35%. i , A i The overlap area ratio of different microscopic components in the sample A to be tested refers to the ratio of the overlap area of ​​the exinite and the vitrinite to the total area. l-v , A l-v is 0.02%, and the ratio of the overlapping area of ​​the vitrinite group and the inert group to the total area is A v-i ,A v-i The total area refers to the sum of the areas of the exinite, vitrinite and inertinite distribution peaks, and the total area is 100%.

[0046] The independent area ratio of the distribution peaks of different microscopic components in the sample B to be tested refers to the ratio of the distribution peak area of ​​the exinite group to the total area. l , B l The ratio of the vitrinite distribution peak area to the total area is 6.41%. v , B v The ratio of the inert group distribution peak area to the total area is 46.83%. i , B i The overlap area ratio of different microscopic components in the sample B to be tested refers to the ratio of the overlap area of ​​the exinite and the vitrinite to the total area. l-v , B l-v is 0.05%, the ratio of the overlapping area of ​​the vitrinite group and the inert group to the total area is B v-i ,B v-i The total area refers to the sum of the areas of the exinite, vitrinite and inertinite distribution peaks, and the total area is 100%.

[0047] Step 5: Calculate the relative contents of different microscopic components in the coal rock according to the independent area ratios and overlapping area ratios of the distribution peaks of different microscopic components in the sample A to be tested calculated in step 4;

[0048] Among them, the relative content of the exinite group M l Expressed as: M l =(A l +0.5A l-v )×100%; relative content of vitrinite M v Expressed as: M v =(0.5A l-v +A v +0.5A v-i )×100%; Relative content of inert group M i Expressed as: M i =(0.5A v-i +Ai )×100%. Substitute the corresponding data in step 4 into the calculation to obtain the relative content M of the exinite group. l The relative content of vitrinite is 6.36%. v The relative content of inert group is 48.66%. i It is 44.98%.

[0049] Step six: Calculate the degree of dissociation of different microscopic components in the coal rock based on the independent area ratio and overlapping area ratio of the distribution peaks of different microscopic components in the sample A to be tested calculated in the step four, and the independent area ratio and overlapping area ratio of the distribution peaks of different microscopic components in the sample B to be tested calculated.

[0050] Wherein, the dissociation degree L of the exin group in step 6 is l It is expressed as: The dissociation degree of vitrinite L v It is expressed as: The dissociation degree of the inert group L i It is expressed as: According to the corresponding data in step 4, the dissociation degree L of the exin group is obtained after substitution into the calculation l 99.54%, vitrinite L v The degree of dissociation is 98.36%, and the inert group L i The degree of dissociation was 98.32%.

[0051] In this embodiment, the dissociation degree of the coal rock microscopic components refers to the relative dissociation degree when the coal grinding product is more fully dissociated. The above dissociation data proves that the different microscopic components of the coal rock have been fully dissociated, that is, the dissociation degree of the sample B to be tested is greater than 95% compared with the sample A to be tested, which can eliminate the problem of low enrichment degree due to incomplete dissociation during the enrichment process. At the same time, the content of different microscopic components in the sample is calculated while calculating the dissociation data. This data can be used as an evaluation of the enrichment degree of the microscopic components. This evaluation method effectively makes up for the deficiency of the traditional national standard method (microscope observation method) that it cannot detect when the content of fine particles (<0.1mm) in the material is relatively high (>10%). At the same time, this method is based on the difference in physical characteristics (density) of the microscopic components of coal rock, and is less affected by the operator, which can effectively make up for the deficiency of the national standard method in requiring the operator to have high professional knowledge of coal rock. Secondly, this method couples narrow density gradient centrifugation and peak fitting, which can effectively solve the problem of overlapping and unclear components when evaluating the separation degree and relative content of coal rock microscopic components by conventional isopycnic gradient centrifugation or conventional floating and sinking experiments. Narrow density gradient centrifugation can fully reflect the density composition and distribution of different microscopic components, and further reflect the sample yield in the overlapping area between different components through peak fitting, that is, the content of samples that are not fully dissociated, which can further improve the accuracy of the evaluation. In addition, this method has low requirements for equipment and operating environment, which can make up for the shortcomings of analytical methods such as national standard method and mineral dissociation analyzer (MLA) in terms of strict requirements on equipment and environment, and can build an experimental platform according to the on-site environment. And this evaluation method also has the advantages of being fast, simple, and convenient, and can respond and evaluate the crushing and grinding process at any time, and guide industrial production in a timely manner.

[0052] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for evaluating the relative content and dissociation degree of coal rock components based on density distribution, characterized in that: The following steps are involved: Step 1: Separate representative test sample A and test sample B from the test coal sample; Step 2: fully dissociate the different microscopic components in the sample A to be tested, and use an isopycnic gradient centrifugation method to sort the dissociated sample A for multiple times, and calculate the average mass fraction of the products at each density level, and then draw a density distribution map of the sample A to be tested; Step 3: sorting the sample B for multiple times by isopycnic gradient centrifugation, and calculating the average mass fraction of products at each density level, and then drawing a density distribution diagram of the sample B for multiple times; Step 4: According to the density distribution diagram of the sample A to be tested in the step 2, a dissociation spectrum of the sample A to be tested is obtained by a peak fitting method, and the independent area and overlapping area ratios of the distribution peaks of different microscopic components in the sample A to be tested are calculated in sequence; According to the density distribution diagram of the sample B to be tested in the step 3, a dissociation spectrum of the sample B to be tested is obtained by a peak fitting method, and the independent area and overlapping area ratios of the distribution peaks of different microscopic components in the sample B to be tested are calculated in sequence; Step 5: Calculate the relative contents of different microscopic components in the coal rock according to the independent area ratios and overlapping area ratios of the distribution peaks of different microscopic components in the sample A to be tested calculated in step 4; Step six, calculating the dissociation degree of different microscopic components in the coal rock according to the independent area ratio and overlapping area ratio of the distribution peaks of different microscopic components in the sample A to be tested calculated in the step four, and the independent area ratio and overlapping area ratio of the distribution peaks of different microscopic components in the sample B to be tested calculated; The sufficient dissociation in step 2 refers to using a disc crusher to crush the sample A to be tested so that the mass proportion of the material with a particle diameter less than 10 μm in the sample A to be tested is greater than or equal to 90%; The independent area ratio of the distribution peaks of different microscopic components in the sample A to be tested in step 4 refers to the ratio of the distribution peak area of ​​the exinite group to the total area. l , the ratio of the vitrinite distribution peak area to the total area A v , the ratio of the inerting group distribution peak area to the total area A i The overlapping area ratio of different microscopic components in the sample A to be tested refers to the ratio of the overlapping area of ​​the exinite and the vitrinite to the total area. l-v , the ratio of the overlapping area of ​​vitrinite and inertinite to the total area A v-i , the total area refers to the sum of the areas of the distribution peaks of exinite, vitrinite and inertinite; The independent area ratio of the distribution peaks of different microscopic components in the sample B to be tested in step 4 refers to the ratio of the distribution peak area of ​​the exinite group to the total area. l , the ratio of the vitrinite distribution peak area to the total area B v , the ratio of the inerting group distribution peak area to the total area B i The overlapping area ratio of different microscopic components in the sample B to be tested refers to the ratio of the overlapping area of ​​the exinite and the vitrinite to the total area. l-v , the ratio of the overlapping area of ​​vitrinite and inertinite to the total area B v-i , the total area refers to the sum of the areas of the distribution peaks of exinite, vitrinite and inertinite; The relative content M of the exinite in step 5 l Expressed as: M l =(A l +0.5A l-v )×100%; relative content of vitrinite M v Expressed as: M v =(0.5A l-v +A v +0.5A v-i )×100%; Relative content of inert group M i Expressed as: M i =(0.5A v-i +A i )×100%; The dissociation degree L of the exinin group in step 6 l It is expressed as: The dissociation degree of vitrinite L v It is expressed as: The dissociation degree of the inert group L i It is expressed as:

2. The method for evaluating the relative content and dissociation degree of coal rock components based on density distribution according to claim 1, characterized in that: The density gradient of the separation medium in the isopycnic gradient centrifugation method in step 2 and step 3 is 0.01 g / cm 3 or 0.02g / cm 3 .

3. The method for evaluating the relative content and dissociation degree of coal rock components based on density distribution according to claim 1, characterized in that: The number of sorting in step 2 and step 3 is at least three times.

4. The method for evaluating the relative content and dissociation degree of coal rock components based on density distribution according to claim 1, characterized in that: The dissociation degree of the coal rock microscopic components refers to the relative dissociation degree when the coal crushing products are relatively fully dissociated.

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