A lignite sample and a method and apparatus for making same

Abstract

The application discloses a lignite sample and a manufacturing method and device thereof. The manufacturing device and method of the lignite sample provide a long-term stable sealing visible environment with surrounding pressure for the lignite sample through winding a transparent heat insulation adhesive tape on the lignite sample and embedding the lignite sample into the inside of the epoxy resin after solidification, which can provide a certain surrounding pressure condition. Meanwhile, the hard epoxy resin shell solves the problem of difficult transportation of the loose and brittle lignite sample on a bumpy road, and the transparent heat insulation adhesive tape and the epoxy resin provide good observation conditions for subsequent core description without damaging the sealing environment. The solidified epoxy resin with surrounding pressure tightly wraps the lignite sample, can reduce the vibration influence during drilling of the small sample, and greatly improves the success rate of drilling of the small sample of the loose and brittle lignite sample. Finally, the solidified epoxy resin shell is removed in a dissolution manner, which is not only convenient, but also can avoid the influence on the physical and chemical properties of the lignite sample.

Description

Technical Field

[0001] This invention relates to a lignite sample and its preparation method and apparatus. Background Technology

[0002] The recoverable coalbed methane resources contained in lignite amount to 4.96 × 10⁻⁶. 12 m 3 Due to the characteristics of lignite, such as low rank, low compaction, stress sensitivity, and susceptibility to water loss and oxidation, coal and rock samples taken to the surface from drilling typically undergo expansion, oxidation, and cracking within a short period. This results in significant discrepancies between the lignite's mechanical properties, pore-fracture characteristics, and adsorption / desorption patterns—key parameters for coalbed methane development—and the samples themselves, leading to severe distortions and hindering scientific guidance for production practices. To avoid rapid distortion of lignite after it leaves the underground environment, preliminary processing is necessary during on-site sampling to prepare specific coal samples. This ensures long-term accuracy, facilitates transportation, and allows for convenient secondary processing and sample preparation.

[0003] Currently, there are three main methods for sample preparation: 1. wrapping with plastic wrap; 2. sealing with wax; and 3. filling with gas canisters. However, all three methods have significant shortcomings. First, none of the three methods can provide effective confining pressure to limit the expansion and cracking of the coal sample after depressurization. Second, the sealing performance of method one is limited, only delaying dehydration and oxidation; while method two can provide good sealing conditions, it is impossible to conduct selective observation during subsequent sample preparation; and method three is not suitable for large-scale use, and the coal sample must be removed in advance during subsequent sample preparation, leading to a certain degree of distortion in the processing. Summary of the Invention

[0004] To at least partially solve any of the above-mentioned technical problems, embodiments of the present invention provide an apparatus and method for preparing high-fidelity lignite samples. While ensuring the high fidelity of the lignite samples, the method is not only convenient for transportation, but also facilitates secondary processing and sample preparation, reducing distortion during the processing.

[0005] As one aspect of the present invention, a method for preparing a lignite sample is provided, the method comprising the following steps:

[0006] S1. Selection and pretreatment of rock samples

[0007] Select lignite rock samples from the target section, conduct water immersion tests, and then dry the surface to obtain lignite rock samples from the target section.

[0008] The target lignite rock sample is evenly wrapped with transparent heat-insulating tape. Several metal frames are added according to the length of the wrapped rock sample to obtain the pretreated target lignite rock sample.

[0009] S2, Fixing of Lignite Rock Sample Encapsulation Casing

[0010] Apply a release agent to the inner surface of the lignite sample encapsulation tube, and push the pretreated target lignite sample obtained in S1 into the horizontally placed lignite sample encapsulation tube.

[0011] After placing the support frame into the threaded end at the bottom of the lignite sample encapsulation cylinder, the lignite sample encapsulation cylinder is erected and fixedly connected to the lower sealing shell.

[0012] S3, Rock Sample Encapsulation

[0013] The mixture of liquid epoxy resin and curing agent is poured into the lignite sample encapsulation tube, and the pretreated target lignite sample is immersed to complete the encapsulation.

[0014] S4, Assembly device

[0015] The upper sealing housing and the lower sealing housing are assembled to form a sealed chamber;

[0016] The temperature and pressure inside the stable sealed chamber are within the set range. After the epoxy resin has completely cured, the upper sealed shell is opened, the lignite sample encapsulation tube is taken out, and after ventilation and curing, the lignite sample is obtained.

[0017] In one or more optional embodiments, in S1, the step of selecting the target lignite rock sample, conducting a water immersion test, and then drying the surface to obtain the target lignite rock sample includes:

[0018] The lignite rock samples were removed from the core tube, sorted, and labeled.

[0019] After observing and describing the lignite rock sample, the target section is selected or the entire cylinder of lignite rock sample is used as the target section;

[0020] The target section of lignite rock sample was placed in clean water for a core immersion test, while surface mud and debris were removed.

[0021] After the lignite sample of the target section stops emitting gas violently, it is taken out of the water and the water stains on the surface of the lignite sample of the target section are wiped off thoroughly to obtain the lignite sample of the target section.

[0022] In one or more optional embodiments, in S1, the target lignite rock sample is uniformly wrapped with transparent heat-insulating tape, and several metal frames are added according to the length of the wrapped rock sample to obtain the pretreated target lignite rock sample, including:

[0023] The target lignite sample, after surface water stains have been wiped off, is evenly wrapped with the transparent heat-insulating tape to ensure that the target lignite sample is completely enclosed without any exposed areas. Then, according to the length of the target lignite sample, a certain number of radially centered metal frames are added to ensure that the target lignite sample does not tilt inside the lignite sample encapsulation tube.

[0024] In one or more optional embodiments, in S2, the step of applying a release agent to the inner surface of the lignite sample encapsulation cylinder and pushing the pretreated target lignite sample obtained in S1 into the horizontally placed lignite sample encapsulation cylinder includes:

[0025] A release agent is applied to the inner surface of the lignite sample encapsulation cylinder. The pretreated target lignite sample obtained in S1 is then pushed into the horizontally placed lignite sample encapsulation cylinder, ensuring that the inner diameter of the encapsulation cylinder is larger than the outer diameter of the pretreated target lignite sample.

[0026] In one or more optional embodiments, in step S3, the step of pouring the mixture of liquid epoxy resin and curing agent into the lignite sample encapsulation cylinder and immersing the lignite sample to complete the encapsulation includes:

[0027] After thoroughly mixing the liquid epoxy resin and the curing agent according to the set ratio, pour the mixture into the lignite sample encapsulation cylinder, keeping the liquid level higher than the length of the pretreated target lignite sample.

[0028] In one or more optional embodiments, in S4, the temperature and pressure within the stable sealed chamber are within a set range, including:

[0029] An air compressor, an air heater, a pressure relief valve, and a pressure gauge are used to stabilize the air pressure in the sealed chamber at a target air pressure, which is close to the in-situ confining pressure beneath the lignite sample.

[0030] In one or more optional embodiments, the method further includes: obtaining lignite samples;

[0031] The acquisition of the lignite sample refers to: immersing the lignite sample in a solvent, and after the cured epoxy resin has dissolved, the lignite sample can be completely removed from the cured epoxy resin.

[0032] As another aspect of the present invention, there is a lignite sample prepared by the above-described preparation method.

[0033] As another aspect of the present invention, an apparatus for preparing the above-mentioned lignite sample is provided, the apparatus comprising: an upper sealing shell, a lower sealing shell, a lignite rock sample encapsulation cylinder, a pressure gauge, a pressure relief valve, an air compressor, and an air heater;

[0034] The upper sealing shell and the lower sealing shell form a sealed chamber, which is used to hold the lignite rock sample encapsulation tube.

[0035] The lignite rock sample encapsulation cylinder is connected to the lower sealing shell by a thread and is used to hold the lignite sample;

[0036] The pressure gauge is installed on the upper sealing housing and is used to observe pressure changes within the sealing chamber;

[0037] The pressure relief valve is disposed in the lower sealing housing and is used to adjust the pressure in the sealing chamber;

[0038] The air heater is disposed in the lower sealed housing and connected to the air compressor.

[0039] In one or more optional embodiments, it further includes: a rubber ring disposed at the connection between the lignite rock sample encapsulation cylinder and the lower sealing shell, for forming a sealed structure.

[0040] In one or more optional embodiments, it further includes: a support frame disposed at the bottom of the lignite rock sample encapsulation cylinder for supporting the lignite rock sample.

[0041] In one or more alternative embodiments, it further includes: a metal frame, the metal frame being radially disposed within the lignite rock sample encapsulation cylinder, for clamping and centering the lignite sample.

[0042] The apparatus and method for preparing lignite samples proposed in this invention provide a long-term, stable, sealed, and visible environment for lignite samples by wrapping transparent heat-insulating tape around the sample and embedding it inside a cured epoxy resin that provides defined confining pressure conditions. Simultaneously, the rigid epoxy resin shell solves the problem of difficult transportation of brittle lignite samples on bumpy mountain roads. The transparent heat-insulating tape and epoxy resin provide good observation conditions for subsequent core characterization without disrupting the sealed environment. The cured epoxy resin tightly encapsulates the lignite sample, reducing the impact of vibration during drilling small samples and significantly improving the success rate of drilling small brittle lignite samples. Finally, the cured epoxy resin shell is removed by melting, which is not only convenient but also avoids affecting the physicochemical properties of the lignite sample.

[0043] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the lignite sample preparation device provided in Embodiment 1 of the present invention;

[0045] Figure 2 This is a schematic diagram of the lignite rock sample encapsulation cylinder and metal frame structure provided by the present invention;

[0046] In the appendix Figure 1 , 2In the middle: 1. Upper sealing shell; 2. Lower sealing shell; 3. Pressure relief valve; 4. Pressure gauge; 5. Air compressor; 6. Air heater; 7. Lignite rock sample encapsulation tube; 8. Metal frame; 9. Support frame; 10. Rubber ring; 11. Pretreated target section lignite rock sample. Detailed Implementation

[0047] In the following description, specific details such as particular structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0048] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0049] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0050] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0051] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0052] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0053] It should be understood that the sequence number of each step in the following embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0054] To illustrate the technical solution of this application, specific embodiments are described below.

[0055] Example 1

[0056] See attached document Figure 1 , 2 This embodiment provides an apparatus for preparing lignite samples, including: an upper sealing shell 1, a lower sealing shell 2, a pressure limiting valve 3, a pressure gauge 4, an air compressor 5, an air heater 6, and a lignite rock sample encapsulation cylinder 7;

[0057] The upper sealing shell 1 and the lower sealing shell 2 form a sealed chamber, which is used to hold the lignite rock sample encapsulation tube 7.

[0058] The lignite rock sample encapsulation cylinder 7 is threadedly connected to the lower sealing shell 2 and is used to hold the lignite sample;

[0059] The pressure gauge 4 is installed on the upper sealing housing 1 and is used to observe the pressure changes in the sealing chamber;

[0060] The pressure relief valve 3 is disposed on the lower sealing housing 2 and is used to adjust the pressure in the sealing chamber;

[0061] The air heater 6 is disposed in the lower sealing housing 2 and is connected to the air compressor 5.

[0062] In this embodiment of the invention, a rubber ring 10 is also included, which is disposed at the connection between the lignite sample encapsulation cylinder 7 and the lower sealing shell 2 to form a sealed structure.

[0063] In this embodiment of the invention, a support frame 9 is also included, which is disposed at the bottom of the lignite rock sample encapsulation cylinder 7 and is used to support the pretreated target lignite rock sample 11.

[0064] In this embodiment of the invention, a metal frame 8 is also included. The metal frame 8 is radially disposed inside the lignite rock sample encapsulation cylinder 7 and is used to clamp and center the pretreated target lignite rock sample 11.

[0065] To enable those skilled in the art to understand the manufacturing apparatus of the present invention more clearly and intuitively, a further description is provided. It should be noted that the connection method, connection order, etc. of the apparatus in this description should not be construed as limitations of the present invention.

[0066] In one specific embodiment, the lignite sample preparation device of the present invention comprises a sealed chamber consisting of an upper sealed shell 1 and a lower sealed shell 2. A pressure gauge 4 is installed on the upper sealed shell 1. The pressure gauge 4 can be installed on the top of the upper sealed shell 1 or on the side of the upper sealed shell 1, depending on actual needs. The pressure gauge 4 is used to observe the pressure changes in the sealed chamber.

[0067] The lower sealing housing 2 is externally connected to a pressure relief valve 3, an air compressor 5, and an air heater 6. The installation positions of the pressure relief valve 3, the air compressor 5, and the air heater 6 can be adjusted according to the actual situation. The pressure relief valve 3 is used to regulate the pressure inside the sealing chamber in real time. The air compressor 5 provides the target air pressure inside the sealing chamber. The air heater 6 is used to maintain the temperature inside the sealing chamber.

[0068] The lower sealing housing 2 has a threaded slot. After the lignite rock sample encapsulation cylinder 7 is screwed into the threaded slot, it is threadedly connected to the lower sealing housing 2. The connection between the lower sealing housing 2 and the lignite rock sample encapsulation cylinder 7 can be a threaded connection or can be replaced by other connection methods.

[0069] A rubber ring 10 provides a seal for the lower sealing shell 2 and the lignite sample encapsulation cylinder 7. A metal frame 8 is placed inside the lignite sample encapsulation cylinder 7, and a support frame 9 is placed at the bottom. The metal frame 8 and the support frame 9 are used to center the pretreated target lignite sample 11. In order to further avoid direct contact between the pretreated target lignite sample 11 and the inner wall of the lignite sample encapsulation cylinder 7, which would affect the local encapsulation quality, the inner diameter of the lignite sample encapsulation cylinder 7 is kept greater than the outer diameter of the pretreated target lignite sample 11.

[0070] Example 2

[0071] Based on the same inventive concept, this embodiment provides a method for preparing a lignite sample, including the following steps:

[0072] S1. Selection and pretreatment of rock samples

[0073] Select lignite rock samples from the target section, conduct water immersion tests, and then dry the surface to obtain lignite rock samples from the target section.

[0074] The target lignite rock sample is evenly wrapped with transparent heat-insulating tape. Several metal frames 8 are added according to the length of the wrapped rock sample to obtain the pretreated target lignite rock sample 11.

[0075] S2, Fixing of Lignite Rock Sample Encapsulation Casing

[0076] Apply a release agent to the inner surface of the lignite sample encapsulation cylinder 7, and push the pretreated target lignite sample 11 obtained in S1 into the horizontally placed lignite sample encapsulation cylinder 7.

[0077] After the support frame 9 is placed into the threaded end at the bottom of the lignite sample encapsulation cylinder 7, the lignite sample encapsulation cylinder 7 is erected and fixedly connected to the lower sealing shell 2.

[0078] S3, Rock Sample Encapsulation

[0079] The mixture of liquid epoxy resin and curing agent is poured into the lignite sample encapsulation cylinder 7 and the pretreated target lignite sample 11 is immersed to complete the encapsulation.

[0080] S4, Assembly device

[0081] The upper sealing housing 1 and the lower sealing housing 2 are assembled to form a sealing chamber;

[0082] The temperature and pressure inside the stable sealed chamber are within the set range. After the epoxy resin has completely cured, the upper sealed shell 1 is opened, the lignite rock sample encapsulation cylinder 7 is taken out, and after ventilation and curing, the lignite sample 11 is obtained.

[0083] In this embodiment of the invention, if multiple target lignite rock samples need to be processed, each target lignite rock sample only needs to repeat S1 to S2, and the total processing time does not exceed 10 minutes. After all the lignite rock sample encapsulation cylinders 7 are fixedly connected to the lower sealing shell 2, S3 is repeated uniformly, and finally S4 is performed to obtain multiple lignite samples.

[0084] In this embodiment of the invention, S1, the step of selecting a target section of lignite rock sample, conducting a water immersion test, and then drying the surface to obtain the target section of lignite rock sample, includes:

[0085] The lignite rock samples were removed from the core tube, sorted, and labeled.

[0086] After observing and describing the lignite rock sample, the target section is selected or the entire cylinder of lignite rock sample is used as the target section;

[0087] The target section of lignite rock sample was placed in clean water for a core immersion test, while surface mud and debris were removed.

[0088] After the lignite sample of the target section stops emitting gas violently, it is taken out of the water and the water stains on the surface of the lignite sample of the target section are wiped off thoroughly to obtain the lignite sample of the target section.

[0089] In this embodiment of the invention, in S1, the target lignite rock sample is uniformly wrapped with transparent heat-insulating tape. Based on the length of the wrapped sample, several metal frames 8 are added to obtain the pre-treated target lignite rock sample 11, including:

[0090] The target lignite sample, after surface water stains have been wiped off, is evenly wrapped with the transparent heat-insulating tape to ensure that the target lignite sample is completely enclosed without any exposed areas. Then, according to the length of the target lignite sample, a certain number of radially centered metal frames 8 are added to ensure that the pretreated target lignite sample 11 does not tilt inside the lignite sample encapsulation cylinder 7.

[0091] In one specific embodiment, the transparent heat-insulating tape provides a 300°C / h barrier, ensuring that the temperature rise of the target section of lignite sample wrapped with the tape does not exceed 25°C.

[0092] In this embodiment of the invention, step S2, which involves applying a release agent to the inner surface of the lignite sample encapsulation cylinder 7 and pushing the pretreated target lignite sample 11 obtained in S1 into the horizontally placed lignite sample encapsulation cylinder 7, includes:

[0093] A release agent is applied to the inner surface of the lignite sample encapsulation cylinder 7. The pretreated target lignite sample 11 obtained in S1 is then pushed into the horizontally placed lignite sample encapsulation cylinder 7, ensuring that the inner diameter of the coal sample encapsulation cylinder 7 is larger than the outer diameter of the pretreated target lignite sample 11.

[0094] In one specific embodiment, a release agent is applied to the inner surface of the lignite sample encapsulation cylinder 7, and the pretreated target lignite sample 11 obtained in S1 is pushed into the horizontally placed lignite sample encapsulation cylinder 7, keeping the inner diameter of the lignite sample encapsulation cylinder 7 2 cm larger than the outer diameter of the pretreated target lignite sample 11.

[0095] In this embodiment of the invention, step S3, which involves pouring the mixture of liquid epoxy resin and curing agent into the lignite sample encapsulation cylinder 7 and immersing the pretreated target lignite sample 11 to complete the encapsulation, includes:

[0096] After thoroughly mixing the liquid epoxy resin and the curing agent according to the set ratio, pour the mixture into the lignite sample encapsulation cylinder 7, keeping the liquid level higher than the length of the pretreated target lignite sample 11.

[0097] In one specific embodiment, the liquid epoxy resin and the curing agent are thoroughly stirred in a 2:1 ratio and then poured into the lignite sample encapsulation cylinder 7, maintaining the liquid level 1 cm above the top of the pretreated target lignite sample 11.

[0098] In this embodiment of the invention, in S4, the temperature and air pressure inside the stable sealed chamber are within a set range, including: using an air compressor 5, a pressure relief valve 3 and a pressure gauge 4 to stabilize the air pressure inside the sealed chamber at a target air pressure, the target air pressure being close to the in-situ confining pressure under the lignite sample, and using an air heater 6 to control the temperature inside the sealed chamber to the optimal temperature for epoxy resin curing.

[0099] In one specific embodiment, the air pressure in the sealed chamber is regulated to the in-situ confining pressure of the lignite sample using an air compressor 5, a pressure relief valve 3, and a pressure gauge 4; the temperature in the sealed chamber is controlled at around 35°C using an air heater 6, so that the internal temperature of the liquid epoxy resin and curing agent mixture does not rise by more than 200°C during the curing process; after stabilizing the temperature and air pressure in the sealed chamber for 15-30 minutes, the epoxy resin is initially cured.

[0100] In this embodiment of the invention, the method further includes: obtaining lignite samples; obtaining lignite samples means: immersing the lignite samples in a solvent, and after the cured epoxy resin has dissolved, the pretreated target lignite rock sample 11 can be completely removed from the cured epoxy resin.

[0101] In one specific embodiment, the soaking time is adjusted according to the actual situation, and soaking is completed as long as the cured epoxy resin melts.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of preparing a lignite sample, characterized by, The method comprises the following steps: S1, selection and pretreatment of rock sample Selecting lignite rock sample of target section, performing water immersion test, drying surface, and obtaining lignite rock sample of target section; Uniformly winding the lignite rock sample of target section with transparent heat insulation tape, adding several metal frames according to the length of the rock sample after winding, and obtaining pretreated lignite rock sample of target section; S2, fixation of lignite rock sample packaging cylinder Smearing release agent on the inner surface of the lignite rock sample packaging cylinder, pushing the pretreated lignite rock sample of target section obtained in S1 into the horizontally placed lignite rock sample packaging cylinder; Placing the support frame into the threaded end at the bottom of the lignite rock sample packaging cylinder, straightening the lignite rock sample packaging cylinder, and fixedly connecting it with the lower sealing shell; S3, packaging of rock sample Pouring the mixed liquid of liquid epoxy resin and curing agent into the lignite rock sample packaging cylinder, and immersing the pretreated lignite rock sample of target section, completing the packaging; S4, assembly of device Assembling the upper sealing shell and the lower sealing shell to form a sealed chamber; Stabilizing the temperature and air pressure in the sealed chamber within a set range, opening the upper sealing shell after the epoxy resin is completely cured, taking out the lignite rock sample packaging cylinder, and obtaining the lignite sample after ventilation and curing; In S4, the stabilization of the temperature and air pressure in the sealed chamber within a set range comprises: Stabilizing the air pressure in the sealed chamber to a target air pressure by using an air compressor, an air heater, a pressure limiting valve and a pressure gauge, and the target air pressure approaches to the in-situ confining pressure of the underground lignite rock sample.

2. The method of producing a lignite sample according to claim 1, characterized in that, In S1, the selection of lignite rock sample of target section, the performance of water immersion test, the drying of surface, and the obtaining of lignite rock sample of target section comprise: Taking out the lignite rock sample from the coring cylinder, sorting and labeling; After observing and describing the lignite rock sample, selecting the target section; Placing the lignite rock sample of target section into clean water to perform core water immersion test, and removing surface mud and debris at the same time; After the lignite rock sample of target section stops emitting gas violently, taking it out of the clean water, wiping off water stains on the surface of the lignite rock sample of target section, and obtaining the lignite rock sample of target section.

3. The method of producing a lignite sample according to claim 1, wherein In S1, the uniform winding of the lignite rock sample of target section with transparent heat insulation tape, the addition of several metal frames according to the length of the rock sample after winding, and the obtaining of pretreated lignite rock sample of target section comprise: Uniformly winding the lignite rock sample of target section with transparent heat insulation tape, ensuring that the lignite rock sample of target section is completely wrapped without exposure, and adding a certain number of radially centered metal frames according to the length of the lignite rock sample of target section to ensure that the lignite rock sample of target section does not tilt in the lignite rock sample packaging cylinder.

4. The method of producing a lignite sample according to claim 1, characterized in that, In S2, the smearing of release agent on the inner surface of the lignite rock sample packaging cylinder, the pushing of the pretreated lignite rock sample of target section obtained in S1 into the horizontally placed lignite rock sample packaging cylinder, and the keeping of the inner diameter of the lignite rock sample packaging cylinder greater than the outer diameter of the pretreated lignite rock sample of target section comprise: Smearing release agent on the inner surface of the lignite rock sample packaging cylinder, pushing the pretreated lignite rock sample of target section obtained in S1 into the horizontally placed lignite rock sample packaging cylinder, and keeping the inner diameter of the lignite rock sample packaging cylinder greater than the outer diameter of the pretreated lignite rock sample of target section.

5. The method of producing a lignite sample according to claim 1, wherein In S3, the mixture of liquid epoxy resin and curing agent is poured into the lignite sample packaging cylinder, and the pretreated target section of lignite sample is immersed, and the packaging is completed, including: After the liquid epoxy resin and the curing agent are fully stirred according to the set proportion, they are poured into the lignite sample packaging cylinder, and the liquid level is kept higher than the length of the pretreated target section of lignite sample.

6. The method of producing a lignite sample according to claim 1, wherein The method further comprises obtaining a lignite sample. The obtaining of the lignite sample refers to soaking the lignite sample in a dissolving agent, and after the solidified epoxy resin is dissolved, the lignite sample can be completely taken out from the solidified epoxy resin.

7. A lignite sample, characterized in that, The lignite sample is obtained by the method for manufacturing a lignite sample according to any one of claims 1-6.

8. An apparatus for producing a lignite sample as claimed in claim 7, characterized in that The manufacturing device comprises an upper sealing shell, a lower sealing shell, a lignite sample packaging cylinder, a pressure gauge, a pressure limiting valve, an air compressor, and an air heater. The upper sealing shell and the lower sealing shell form a sealed chamber, and the sealed chamber is used to hold the lignite sample packaging cylinder. The lignite sample packaging cylinder is connected with the lower sealing shell through threads, and is used to hold the lignite sample. The pressure gauge is installed on the upper sealing shell, and is used to observe the pressure change in the sealed chamber. The pressure limiting valve is arranged on the lower sealing shell, and is used to adjust the pressure in the sealed chamber. The air heater is arranged on the lower sealing shell, and is connected with the air compressor.

9. The apparatus according to claim 8, characterized in that Further comprising: A rubber ring, The rubber ring is arranged at the connection between the lignite sample packaging cylinder and the lower sealing shell, and is used to form a closed structure.

10. The apparatus of claim 8, wherein, Further comprising: A support frame, The support frame is arranged at the bottom of the lignite sample packaging cylinder, and is used to support the lignite sample.

11. The apparatus of claim 8, wherein, Further comprising: A metal frame, The metal frame is radially arranged in the lignite sample packaging cylinder, and is used to hold and center the lignite sample.

Images