Method for analyzing clay minerals and non-clay minerals in coal mine

Abstract

The invention relates to the technical field of mineral detection and analysis, in particular to a method for analyzing clay minerals and non-clay minerals in a coal mine. The method comprises the following steps: pretreating a coal sample to be detected to obtain pulverized coal; carrying out plasma ashing on the pulverized coal to completely oxidize organic matters in the pulverized coal to obtain an ashed sample; carrying out X-ray diffraction analysis on the ashed sample to obtain an X-ray diffraction spectrogram of the ashed sample; performing data conversion on the X-ray diffraction spectrogram, and performing non-clay mineral retrieval comparative analysis on the converted data to respectively obtain clay mineral data and non-clay mineral data; the method can realize effective separation and accurate analysis of clay minerals and non-clay minerals in the coal sample so as to realize accurate analysis of the coal sample.

Description

Technical Field

[0001] This application relates to the technical field of mineral detection and analysis, and particularly to a method for analyzing clay minerals and non-clay minerals in coal mines. Background Art

[0002] Since each mineral in a rock has a specific crystal structure, such as different interplanar spacings, and in X-ray diffraction analysis, a series of crystal characteristic diffraction patterns can be obtained at a fixed X-ray wavelength. According to the diffraction angle corresponding to the diffraction peak and using Bragg's equation, the interplanar spacing of the corresponding mineral can be calculated, thereby being used to identify the types and contents of minerals in the rock.

[0003] However, the minerals in coal have experienced a complex coalification process together with plant residues and are also one of the components of coal. Therefore, the types of mineral components in coal are complex and diverse, and there are significant differences in content among different coal types in different regions. And the mineral components have an important impact on application fields such as coalbed methane development, coal mining, coal washing, combustion, coking, and gasification. Therefore, analyzing and detecting clay minerals and common non-clay minerals in coal is helpful for the clean and efficient utilization of coal resources.

[0004] Since the main component of coal is organic matter, the minerals are widely dispersed in coal and the particles are sometimes extremely fine, making it difficult to directly separate them from coal. Therefore, it is difficult to accurately analyze clay minerals and common non-clay minerals in coal directly using an X-ray diffractometer. Therefore, it is very necessary to develop a method for extracting inorganic minerals in coal to achieve accurate detection of clay minerals and common non-clay minerals. Summary of the Invention

[0005] This application provides a method for analyzing clay minerals and non-clay minerals in coal mines to solve the technical problem that it is difficult to directly separate minerals from coal in the prior art and thus difficult to accurately analyze clay minerals and common non-clay minerals in coal by an X-ray diffractometer.

[0006] In a first aspect, this application provides a method for analyzing clay minerals and non-clay minerals in coal mines, and the method includes:

[0007] Pre-treat a coal sample to be measured to obtain pulverized coal;

[0008] Perform plasma ashing on the pulverized coal so that all the organic matter in the pulverized coal is oxidized to obtain an ashed sample;

[0009] Perform X-ray diffraction analysis on the ashed sample to obtain an X-ray diffraction pattern of the ashed sample;

[0010] Perform data conversion on the X-ray diffraction pattern, and then conduct retrieval and comparative analysis of non-clay minerals on the converted data to obtain clay mineral data and non-clay mineral data respectively.

[0011] Optionally, the temperature of the plasma ashing is ≤120°C, and the time of the plasma ashing is ≥10 h.

[0012] Optionally, the plasma ashing includes performing plasma ashing by means of radio frequency combustion, the radio frequency power of the radio frequency combustion is 75 W - 85 W, and the radio frequency of the radio frequency combustion is 12.5 MHz - 14.0 MHz.

[0013] Optionally, the radio frequency combustion includes performing radio frequency combustion with oxygen, and the pressure of the oxygen is ≥0.01 MPa.

[0014] Optionally, the vacuum degree of the plasma ashing is ≤133 Pa.

[0015] Optionally, the emission slit and the scattering slit used in the X-ray diffraction analysis are respectively 0.5° - 1.5°, and the receiving slit used in the X-ray diffraction analysis is 0.10 mm - 0.15 mm.

[0016] Optionally, the scanning speed used in the X-ray diffraction analysis is 1.5° / min - 2.5° / min; and / or,

[0017] the scanning range used in the X-ray diffraction analysis is 2.5° - 45°; and / or,

[0018] the sampling step width used in the X-ray diffraction analysis is 0.015° - 0.025°.

[0019] Optionally, the pretreatment of the coal sample to be measured to obtain pulverized coal includes the steps of:

[0020] Crush the coal sample, screen the crushed coal sample, and then perform sample reduction on the screened coal sample to obtain an initial coal sample;

[0021] Judge whether the initial coal sample needs to be dried according to the water content of the initial coal sample;

[0022] If so, perform constant-temperature drying on the initial coal sample to obtain a dried pulverized coal sample;

[0023] Grind the dried pulverized coal sample to obtain pulverized coal.

[0024] Optionally, the aperture of the sieve used for screening is ≤1.0 mm; and / or,

[0025] the temperature of the constant-temperature drying is ≤60°C.

[0026] Optionally, determining whether the initial coal sample needs to be dried according to the water content of the initial coal sample includes the steps of:

[0027] Determining whether the initial coal sample needs to be dried according to the magnitudes of the water content of the initial coal sample and the standard water content;

[0028] If the water content of the initial coal sample > the standard water content, subject the initial coal sample to constant-temperature drying to obtain a dried pulverized coal sample;

[0029] If the water content of the initial coal sample ≤ the standard water content, directly grind the initial coal sample to obtain pulverized coal;

[0030] Wherein, the standard water content ≤ 5%.

[0031] The above technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0032] A method for analyzing clay minerals and non-clay minerals in coal mines provided by the embodiments of the present application first pre-treats a coal sample to be measured to obtain dried pulverized coal, and then performs plasma ashing on the pulverized coal. Since plasma ashing can completely break the chemical bonds of organic macromolecules in coal to form new bonds, but the energy is much lower than that of high-energy radioactive rays, it only involves the surface of the coal and does not affect the properties of the coal matrix. Therefore, through plasma ashing, the organic matter in the coal sample is completely oxidized, which can make only clay minerals and non-clay minerals remain in the coal sample. Then, X-ray diffraction analysis is performed for scanning analysis, and the analysis data is transformed. Finally, through the method of retrieval and comparative analysis, the data of non-clay minerals and the data of clay minerals are separated, so as to finally obtain clay minerals and non-clay minerals respectively; therefore, this method can effectively separate and accurately analyze clay minerals and non-clay minerals in the coal sample to achieve accurate analysis of the coal sample. Description of the Drawings

[0033] The drawings here are incorporated into the specification and form a part of this specification, showing the embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a schematic flowchart of a method for analyzing clay minerals and non-clay minerals in coal mines provided by the embodiments of the present application;

[0036] Figure 2 Schematic diagram of the detailed process of a method for analyzing clay minerals and non-clay minerals in coal provided by an embodiment of the present application;

[0037] Figure 3 Schematic diagram of the pretreatment in a method for analyzing clay minerals and non-clay minerals in coal provided by an embodiment of the present application;

[0038] Figure 4 Comparison chart of the results of X-ray diffraction analysis provided by Example 1 of the present application and X-ray diffraction analysis provided by Comparative Example 1;

[0039] Figure 5 Comparison chart of the results of X-ray diffraction analysis provided by Example 2 of the present application and X-ray diffraction analysis provided by Comparative Example 2;

[0040] Figure 6 Comparison chart of the results of X-ray diffraction analysis provided by Example 3 of the present application and X-ray diffraction analysis provided by Comparative Example 3. Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0042] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the present application can be obtained through market purchase or can be prepared by existing methods.

[0043] The creative thinking of the present application is as follows:

[0044] The polycrystalline X-ray diffraction analysis method is a non-destructive analysis method, which mainly uses a small amount of crystalline powder or polycrystalline bulk samples for detection to obtain the corresponding X-ray diffraction pattern; generally, the sample will not be chemically damaged during the overall analysis process, and the sample after the experiment can still be used for subsequent other test and research work. This shows that the polycrystalline X-ray diffraction analysis method has the advantages of easy sample preparation and small sample consumption, so the applicable range of this analysis method is very wide. Since the main component of coal is organic matter, which has a non-crystalline structure, and the content of clay minerals and non-clay minerals in the composition of coal is small, a plasma asher is used to slowly ash the coal sample at low temperature to remove the organic matter in the coal, and then an X-ray diffractometer can be used to analyze the components and contents of clay minerals and common non-clay minerals in the coal.

[0045] Since plasma is a unique phenomenon and substance generated by gas molecules in special situations such as vacuum and discharge, the typical composition of plasma is electrons, ions, free radicals, and protons. The free radicals and ions generated by the gas have high activity, and their energy is sufficient to break almost all chemical bonds and can completely break the chemical bonds of organic macromolecules in coal to form new bonds, but the energy is much lower than that of high-energy radioactive rays. Therefore, it only affects the surface of coal without affecting the properties of the coal matrix. Therefore, using a plasma asher to slowly ash coal samples at low temperature can effectively remove the organic matter in coal without destroying the structural composition of minerals in coal.

[0046] At the same time, press the powder of the coal sample after plasma ashing into tablets, scan it with an X-ray diffractometer, and use professional data processing software to perform qualitative and quantitative analysis of common non-clay minerals such as clay minerals, quartz, calcite, dolomite, ankerite, siderite, anhydrite, gypsum, mirabilite, barite, pyrite, halite, plagioclase, potassium feldspar, glauberite, laumontite, analcime, anatase, etc., so as to complete the accurate analysis of clay minerals and non-clay minerals in the coal sample.

[0047] Figure 1 Exemplarily shows a schematic flow chart of a method for analyzing clay minerals and non-clay minerals in coal mines provided by an embodiment of the present application;

[0048] As Figure 1 shown, an embodiment of the present application provides a method for analyzing clay minerals and non-clay minerals in coal mines, and the method includes:

[0049] S1. Pretreat the coal sample to be tested to obtain coal powder;

[0050] S2. Perform plasma ashing on the coal powder so that all the organic matter in the coal powder is oxidized to obtain an ashed sample;

[0051] S3. Perform X-ray diffraction analysis on the ashed sample to obtain the X-ray diffraction pattern of the ashed sample;

[0052] S4. Perform data conversion on the X-ray diffraction pattern, and then perform retrieval and comparison analysis of non-clay minerals on the converted data to obtain clay mineral data and non-clay mineral data respectively.

[0053] In the embodiment of the present application, by introducing the method of plasma ashing, the organic matter in the coal powder can be fully oxidized by plasma ashing, so that coal samples of clay minerals and non-clay minerals can be obtained, avoiding the influence of organic matter in subsequent X-ray diffraction analysis, and thus realizing the accurate detection of clay minerals and non-clay minerals in coal samples.

[0054] It should be noted that the non-clay minerals can be quartz, calcite, dolomite, ankerite, siderite, anhydrite, gypsum, mirabilite, barite, pyrite, halite, plagioclase, potassium feldspar, glauberite, laumontite, analcime or anatase.

[0055] In some alternative embodiments, the temperature of the plasma ashing is ≤ 120°C, and the time of the plasma ashing is ≥ 10 h.

[0056] In the embodiments of the present application, by defining the specific temperature and specific time of the plasma ashing, on the one hand, the organic matter in the coal sample can be fully oxidized by the slow plasma ashing method, and on the other hand, the energy of this slow plasma ashing method is much lower than that of high-energy radioactive rays. Therefore, only the surface of the coal changes without affecting the performance of the mineral system in the coal.

[0057] In some alternative embodiments, the plasma ashing includes plasma ashing by radio frequency combustion. The radio frequency power of the radio frequency combustion is 75 W to 85 W, and the radio frequency of the radio frequency combustion is 12.5 MHz to 14.0 MHz.

[0058] In some alternative embodiments, the radio frequency combustion includes radio frequency combustion with oxygen, and the pressure of the oxygen is ≥ 0.01 MPa.

[0059] In the embodiments of the present application, by defining the specific radio frequency power, radio frequency and oxygen pressure in the plasma ashing, the oxygen can be turned into oxygen ions by the plasma ashing and react completely with the organic matter in the coal sample, so that the organic matter is separated from the coal sample, and thus a coal sample containing clay minerals and non-clay minerals can be obtained, improving the accuracy of subsequent X-ray diffraction analysis.

[0060] The radio frequency power of the radio frequency combustion can be 75 W, 76 W, 77 W, 78 W, 79 W, 80 W, 81 W, 82 W, 83 W, 84 W or 85 W.

[0061] The radio frequency of the radio frequency combustion can be 12.5 MHz, 12.6 MHz, 12.7 MHz, 12.8 MHz, 12.9 MHz, 13.0 MHz, 13.1 MHz, 13.2 MHz, 13.3 MHz, 13.4 MHz, 13.5 MHz, 13.56 MHz, 13.6 MHz, 13.7 MHz, 13.8 MHz, 13.9 MHz or 14.0 MHz.

[0062] In some alternative embodiments, the vacuum degree of the plasma ashing is ≤ 133 Pa.

[0063] In the embodiments of the present application, by controlling the specific vacuum degree for plasma ashing, oxygen can quickly enter the plasma asher, and oxygen can be quickly converted into cations, thus facilitating the plasma ashing to proceed in an oxygen-rich atmosphere, and finally removing the organic matter in the coal sample to obtain a coal sample containing clay minerals and non-clay minerals.

[0064] In some alternative embodiments, the emission slit and the scattering slit used for the X-ray diffraction analysis are respectively 0.5° - 1.5°, and the receiving slit used for the X-ray diffraction analysis is 0.10 mm - 0.15 mm.

[0065] In some alternative embodiments, the scanning speed used for the X-ray diffraction analysis is 1.5° / min - 2.5° / min; and / or,

[0066] the scanning range used for the X-ray diffraction analysis is 2.5° - 45°; and / or,

[0067] the sampling step width used for the X-ray diffraction analysis is 0.015° - 0.025°.

[0068] In the embodiments of the present application, by defining the various parameters used for the X-ray diffraction analysis, the clay minerals and non-clay minerals in the coal sample containing clay minerals and non-clay minerals can be fully detected, and an X-ray diffraction pattern can be formed, facilitating the subsequent retrieval and comparative analysis, thereby improving the detection accuracy.

[0069] The emission slit and the scattering slit can be 0.5°, 0.6°, 0.7°, 0.8°, 0.9°, 1.0°, 1.1°, 1.2°, 1.3°, 1.4° or 1.5° respectively.

[0070] The receiving slit can be 0.10 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm or 0.15 mm.

[0071] The scanning speed can be 1.5° / min, 1.6° / min, 1.7° / min, 1.8° / min, 1.9° / min, 2.0° / min, 2.1° / min, 2.2° / min, 2.3° / min, 2.4° / min or 2.5° / min.

[0072] The scanning range can be 2.5°, 5.0°, 7.5°, 10.0°, 12.5°, 15.0°, 17.5°, 20.0°, 22.5°, 25.0°, 27.5°, 30.0°, 32.5°, 35.0°, 37.5°, 40.0°, 42.5° or 45.0°.

[0073] The sampling step width can be 0.015°, 0.016°, 0.017°, 0.018°, 0.019°, 0.020°, 0.021°, 0.022°, 0.023°, 0.024° or 0.025°.

[0074] Figure 2 Exemplarily shown is a detailed flowchart of a method for analyzing clay minerals and non-clay minerals in coal mines provided by an embodiment of the present application;

[0075] As Figure 2 shown, in some alternative embodiments, the pretreatment of the coal sample to be measured to obtain pulverized coal includes the steps of:

[0076] S101. Crush the coal sample, screen the crushed coal sample, and then perform sample reduction on the screened coal sample to obtain an initial coal sample;

[0077] S102. Determine whether the initial coal sample needs to be dried according to the water content of the initial coal sample;

[0078] If so, perform constant-temperature drying on the initial coal sample to obtain a dried pulverized coal sample;

[0079] S103. Grind the dried pulverized coal sample to obtain pulverized coal.

[0080] In the embodiment of the present application, by refining the specific steps of the pretreatment of the coal sample to be measured, through crushing and screening, the coal sample to be measured can be made into an initial coal sample with a large specific surface area. Then, the water content of the initial coal sample is determined to clarify whether drying is required. Finally, through grinding, a pulverized coal sample that is fully dried and has the largest specific surface area can be obtained.

[0081] In some alternative embodiments, the aperture of the sieve used for screening is ≤ 1.0 mm; and / or,

[0082] The temperature of the constant-temperature drying is ≤ 60°C.

[0083] In the embodiment of the present application, by refining the aperture of the sieve, an initial coal sample with a large specific surface area can be obtained, which is convenient for subsequent drying and grinding, and thus finally a pulverized coal with a large specific surface area can be obtained, which is convenient for subsequent plasma ashing.

[0084] Controlling the specific temperature of the constant-temperature drying can fully remove the moisture in the coal and facilitate subsequent grinding to obtain a pulverized coal sample with a large specific surface area.

[0085] Figure 3 Exemplarily shown is a schematic diagram of the pretreatment in a method for analyzing clay minerals and non-clay minerals in coal mines provided by an embodiment of the present application;

[0086] As Figure 3 shown, in some alternative embodiments, determining whether it is necessary to dry the initial coal sample according to the water content of the initial coal sample includes the steps of:

[0087] S112. Determine whether it is necessary to dry the initial coal sample according to the magnitudes of the water content of the initial coal sample and the standard water content;

[0088] If the water content of the initial coal sample > the standard water content, subject the initial coal sample to constant-temperature drying to obtain a dried pulverized coal sample;

[0089] If the water content of the initial coal sample ≤ the standard water content, directly grind the initial coal sample to obtain pulverized coal;

[0090] wherein, the standard water content ≤ 5%.

[0091] In the embodiments of the present application, by refining the drying standard, pulverized coal with extremely low water content can be obtained, facilitating the subsequent effect of plasma ashing, thereby fully oxidizing the organic matter in the pulverized coal.

[0092] The following further elaborates the present application in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods without specific conditions noted in the following embodiments are generally determined according to industry standards. If there is no corresponding industry standard, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0093] Example 1

[0094] As Figure 3 shown, a method for analyzing clay minerals and non-clay minerals in coal mines includes:

[0095] I. Coal sample preparation:

[0096] 1. Crush the coal sample to be tested, sieve it through a test sieve with a pore size of 1.0 mm, and then weigh 5 g of the coal sample after reduction and bag it;

[0097] 2. If the moisture content of the coal sample is too high, it should be dried first in a constant-temperature oven at a temperature not higher than 60°C;

[0098] 3. Grind the dried pulverized coal in an agate mortar until there is no granular feeling when touched by hand, and then bag it.

[0099] II. Coal sample ashing

[0100] 1. Weigh 5 g of the dried coal sample, put it flat in a glassware, and place it in the oxidation chamber of a plasma asher (model: FEMTO), and close the chamber door;

[0101] 2. Turn on the plasma asher and set the instrument parameters: the radio frequency power is 80 W and the operating frequency is 13.56 MHz;

[0102] 3. Start the vacuum pump to keep the vacuum degree in the chamber below 133 Pa;

[0103] 4. Introduce oxygen and keep the pressure at 0.01 MPa;

[0104] 5. Start the plasma ashing program to start slow ashing. Pause the work every 5 h, stir the coal sample with a thin glass rod, spread it evenly, and then continue ashing until all the organic matter in the coal sample is oxidized, then stop the ashing work.

[0105] III. X-ray diffraction analysis

[0106] 1. Place the ashed sample powder in the groove of the sample carrier and compact it to keep it flat and even with the surface of the sample carrier, avoiding preferred orientation of the crystal powder;

[0107] 2. Turn on the X-ray diffractometer (model: XRD-7000) and set the analysis parameters:

[0108] (1) Emission slit and scattering slit: 1°;

[0109] (2) Receiving slit: 0.15 mm;

[0110] (3) Scanning speed: 2θ is 2° / min;

[0111] (4) Sampling step width: 2θ is 0.02°;

[0112] (5) 2θ scanning range: 2.5° - 45°;

[0113] 3. Start the X-ray diffractometer to measure the sample and obtain the X-ray diffraction pattern;

[0114] 4. Use the professional software of the X-ray diffractometer to process the data, retrieve common non-clay minerals such as clay minerals, quartz, calcite, dolomite, ankerite, siderite, anhydrite, gypsum, mirabilite, barite, pyrite, halite, plagioclase, potassium feldspar, glauberite, laumontite, analcime, anatase, etc., and conduct quantitative analysis. The results are as Figure 4 shown.

[0115] Example 2

[0116] Compare Example 2 with Example 1. The difference between Example 2 and Example 1 is that:

[0117] The temperature of plasma ashing is 110 °C and the time of plasma ashing is 12 h.

[0118] Plasma ashing includes performing plasma ashing by means of radio frequency combustion, the radio frequency power of the radio frequency combustion being 75 W and the radio frequency of the radio frequency combustion being 12.5 MHz.

[0119] The emission slit and the scattering slit used in the X-ray diffraction analysis are 0.5° respectively, and the receiving slit used in the X-ray diffraction analysis is 0.10 mm;

[0120] The scanning speed used in the X-ray diffraction analysis is 1.5° / min;

[0121] The scanning range used in the X-ray diffraction analysis is 2.5°;

[0122] The sampling step width used in the X-ray diffraction analysis is 0.015°.

[0123] Example 3

[0124] Comparing Example 3 with Example 1, the difference between Example 3 and Example 1 is as follows:

[0125] The temperature of the plasma ashing is 100 °C, and the time of the plasma ashing is 15 h.

[0126] Plasma ashing includes performing plasma ashing by means of radio frequency combustion, the radio frequency power of the radio frequency combustion being 85 W and the radio frequency of the radio frequency combustion being 14.0 MHz.

[0127] The emission slit and the scattering slit used in the X-ray diffraction analysis are 1.5° respectively, and the receiving slit used in the X-ray diffraction analysis is 0.15 mm;

[0128] The scanning speed used in the X-ray diffraction analysis is 2.5° / min;

[0129] The scanning range used in the X-ray diffraction analysis is 45°;

[0130] The sampling step width used in the X-ray diffraction analysis is 0.025°.

[0131] Comparative Example 1

[0132] Comparing Comparative Example 1 with Example 1, the difference between Comparative Example 1 and Example 1 is as follows:

[0133] Without using plasma ashing, directly perform X-ray diffraction analysis on the pulverized coal.

[0134] Comparative Example 2

[0135] Comparing Comparative Example 2 with Example 2, the difference between Comparative Example 2 and Example 2 is as follows:

[0136] Directly perform X-ray diffraction analysis on pulverized coal without using plasma ashing.

[0137] Comparative Example 3

[0138] Compare Comparative Example 3 with Example 3. The differences between Comparative Example 3 and Example 3 are as follows:

[0139] Directly perform X-ray diffraction analysis on pulverized coal without using plasma ashing.

[0140] Related results and analysis:

[0141] Figure 4 Exemplarily shows a comparison chart of the results of X-ray diffraction analysis provided in Example 1 of the present application and the X-ray diffraction analysis provided in Comparative Example 1;

[0142] Separate statistics are made on the X-ray diffraction analysis spectra obtained in Example 1 and Comparative Example 1, and the results are as Figure 4 shown.

[0143] At the same time, statistics and comparisons are made on the X-ray diffraction analysis spectra obtained in Example 2 and Comparative Example 2 and Example 3 and Comparative Example 3, and the results are as Figure 5 、 Figure 6 shown, which shows that the detection results of this method are relatively accurate.

[0144] From Figure 4 and Figure 5 、 Figure 6 it can be seen that a method for analyzing clay minerals and non-clay minerals in coal provided in the embodiments of the present application, through preprocessing the coal sample to be tested and then performing plasma ashing treatment, enables all the organic matter in the coal sample to be oxidized, which can make only clay minerals and non-clay minerals remain in the coal sample. Then, through X-ray diffraction analysis for scanning analysis and data conversion of the analysis data, and finally through the method of retrieval and comparative analysis, the effective separation and accurate analysis of clay minerals and non-clay minerals in the coal sample can be realized, so as to achieve the accurate analysis of the coal sample.

[0145] And in the traditional method, the mineral content in coal is determined according to the national standard of GB / T 7560 "Methods for Determination of Minerals in Coal", but this method requires the use of dangerous chemical reagents such as hydrochloric acid and hydrofluoric acid, while the method provided in the embodiments of the present application combines a plasma ashing instrument and an X-ray diffractometer and does not require the use of any chemical reagents.

[0146] At the same time, GB / T 7560 "Methods for Determination of Minerals in Coal" is only applicable to the determination of the total mineral content in coal and cannot determine the components and contents of clay minerals and common non-clay minerals in coal, while the method provided in the embodiments of the present application can realize the separate determination of clay minerals and 17 non-clay mineral components in coal.

[0147] Moreover, although the coal and rock samples can be directly scanned and analyzed by an X-ray diffractometer compared with traditional methods, since the main component of coal is organic matter, the analysis effect of the X-ray diffractometer is poor, and effective separation of different types of minerals cannot be achieved. However, the method provided by the implementation of this application realizes the effective separation of clay minerals and 17 non-clay minerals in coal samples through retrieval and comparative analysis.

[0148] The various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the description of the range has specifically disclosed all possible sub-ranges and single values within that range. For example, it should be considered that the description of the range from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within that range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0149] In this application, unless otherwise stated, the orientation terms such as "upper" and "lower" specifically refer to the drawing direction in the drawings. Additionally, in the description of this application's specification, the terms "including", "comprising", etc. mean "including but not limited to". In this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this text, "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. In this text, "at least one" means one or more, and "multiple" means two or more. "At least one kind", "at least one of the following items (pieces)" or similar expressions refer to any combination of these items, including any combination of single items (pieces) or plural items (pieces). For example, "at least one of a, b, or c", or, "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0150] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for analyzing clay minerals and non-clay minerals in coal mines, characterized in that, The method includes: Pre-treating a coal sample to be measured to obtain pulverized coal; Performing plasma ashing on the pulverized coal to oxidize all the organic matter in the pulverized coal, obtaining an ashed sample; Performing X-ray diffraction analysis on the ashed sample to obtain an X-ray diffraction pattern of the ashed sample; Converting the data of the X-ray diffraction pattern, and then performing retrieval and comparative analysis of non-clay minerals on the converted data to obtain clay mineral data and non-clay mineral data respectively.

2. The method according to claim 1, characterized in that The temperature of the plasma ashing is ≤120 °C, and the time of the plasma ashing is ≥10 h.

3. The method according to claim 1, wherein The plasma ashing includes performing plasma ashing by means of radio frequency combustion, the radio frequency power of the radio frequency combustion is 75 W - 85 W, and the radio frequency of the radio frequency combustion is 12.5 MHz - 14.0 MHz.

4. The method according to claim 3, wherein The radio frequency combustion includes performing radio frequency combustion with oxygen, and the pressure of the oxygen is ≥0.01 MPa.

5. The method according to claim 1, wherein The vacuum degree of the plasma ashing is ≤133 Pa.

6. The method according to claim 1, characterized in that The emission slit and the scattering slit used for the X-ray diffraction analysis are respectively 0.5° - 1.5°, and the receiving slit used for the X-ray diffraction analysis is 0.10 mm - 0.15 mm.

7. The method according to claim 1, characterized in that, The scanning speed used for the X-ray diffraction analysis is 1.5° / min - 2.5° / min; and / or, The scanning range used for the X-ray diffraction analysis is 2.5° - 45°; and / or, The sampling step width used for the X-ray diffraction analysis is 0.015° - 0.025°.

8. The method according to claim 1, characterized in that, The pre-treating the coal sample to be measured to obtain pulverized coal includes the steps of: Crushing the coal sample, screening the crushed coal sample, and then performing sample reduction on the screened coal sample to obtain an initial coal sample; Judging whether the initial coal sample needs to be dried according to the water content of the initial coal sample; If so, performing constant-temperature drying on the initial coal sample to obtain a dried pulverized coal sample; Grinding the dried pulverized coal sample to obtain pulverized coal.

9. The method according to claim 8, characterized in that The aperture of the sieve used for the screening is ≤1.0 mm; and / or, The temperature of the constant-temperature drying is ≤60 °C.

10. The method according to claim 8, wherein The judging whether the initial coal sample needs to be dried according to the water content of the initial coal sample includes the steps of: Judging whether the initial coal sample needs to be dried according to the size of the water content of the initial coal sample and the standard water content; If the water content of the initial coal sample > the standard water content, performing constant-temperature drying on the initial coal sample to obtain a dried pulverized coal sample; If the water content of the initial coal sample ≤ the standard water content, directly grinding the initial coal sample to obtain pulverized coal; Wherein, the standard water content is ≤5%.

Images