Rock sample preparation method and system for scanning electron microscope

Abstract

The rock sample preparation method for a scanning electron microscope provided by the embodiments of the present disclosure comprises: performing mechanical grinding and polishing treatment on a rock; performing argon ion polishing treatment on the rock subjected to the mechanical grinding and polishing treatment; performing film plating treatment on the rock subjected to the argon ion polishing treatment to obtain a rock sample; and the rock sample is used for a scanning electron microscope. Here, by performing mechanical grinding and polishing on the rock first and then performing argon ion polishing treatment, compared with only performing polishing treatment on the rock in a single mode, the rock sample with a more smooth and flat observation surface and clear pores under the scanning electron microscope can be obtained, and the observation and research effect of the scanning electron microscope on the rock sample is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to, but is not limited to, the field of geology, and in particular, to a rock sample preparation method and system for scanning electron microscopy. BACKGROUND

[0002] Scanning electron microscopy can be used to analyze rock to obtain information such as morphology, structure, composition, and / or crystallography of the rock, and is increasingly widely used in various application scenarios such as scientific research, exploration, and / or mining.

[0003] Rock samples prepared by existing technologies often have a small observation surface area and / or low imaging quality under a scanning electron microscope, which greatly affects the observation and research of the rock samples by the scanning electron microscope. SUMMARY

[0004] Therefore, the present disclosure provides a rock sample preparation method and system for scanning electron microscopy.

[0005] According to a first aspect of the present disclosure, a rock sample preparation method for scanning electron microscopy is provided, the method comprising:

[0006] mechanically grinding and polishing the rock;

[0007] argon ion polishing the rock subjected to the mechanical grinding and polishing;

[0008] coating the rock subjected to the argon ion polishing to obtain a rock sample; wherein the rock sample is used for scanning electron microscopy.

[0009] In one embodiment, the method further comprises, before the mechanical grinding and polishing of the rock, semi-embeddedly embedding a rock of a predetermined volume. In one embodiment, the semi-embeddedly embedding of the rock of the predetermined volume comprises: adding an embedding agent to a semi-embedded embedding mold; placing the rock of the predetermined volume into the semi-embedded embedding mold; and continuously adding the embedding agent to the semi-embedded embedding mold until a distance between a stacking surface of the embedding agent and an observation surface of the rock is within a preset range.

[0010] In one embodiment, the mechanical grinding and polishing comprises: rough grinding the rock; fine grinding the rock subjected to the rough grinding; and mechanically polishing the rock subjected to the fine grinding.

[0011] In one embodiment, the argon ion polishing comprises: adjusting a height of the observation surface of the rock so that the observation surface of the rock can be used for polishing; and argon ion polishing the rock by using predetermined polishing parameters.

[0012] In an embodiment, the argon ion polishing treatment on the rock by the predetermined polishing parameter comprises: performing argon ion polishing treatment on the rock by argon ions at a first voltage; performing argon ion polishing treatment on the rock by argon ions at a second voltage, wherein the second voltage is lower than the first voltage.

[0013] In an embodiment, the coating treatment comprises: performing vacuum coating treatment on the rock according to predetermined coating parameters.

[0014] In an embodiment, the predetermined polishing parameter comprises at least one of the following: voltage; current; polishing duration; number of ion guns; angle of ion guns.

[0015] In an embodiment, the method further comprises: obtaining a rock of a predetermined volume by cutting and shaping.

[0016] In an embodiment, the method further comprises: after performing mechanical grinding and polishing treatment on the rock subjected to the half-encapsulation treatment, performing cleaning and drying treatment on the rock subjected to the mechanical grinding and polishing treatment.

[0017] In a second aspect, the embodiments of the present disclosure provide a rock sample preparation system for a scanning electron microscope, the system comprising:

[0018] performing half-encapsulation treatment on the rock of the predetermined volume;

[0019] a mechanical grinding and polishing device for performing mechanical grinding and polishing treatment on the rock of the predetermined volume subjected to the half-encapsulation treatment;

[0020] an argon ion polishing device for performing argon ion polishing treatment on the rock subjected to the mechanical grinding and polishing treatment;

[0021] a coating device for performing coating treatment on the rock subjected to the argon ion polishing treatment, to obtain a rock sample; wherein the rock sample is used for the scanning electron microscope.

[0022] The rock sample preparation method for a scanning electron microscope provided by the embodiments of the present disclosure comprises: performing mechanical grinding and polishing treatment on a rock; performing argon ion polishing treatment on the rock subjected to the mechanical grinding and polishing treatment; and performing coating treatment on the rock subjected to the argon ion polishing treatment, to obtain a rock sample; wherein the rock sample is used for the scanning electron microscope. By performing mechanical grinding and polishing treatment on the rock first and then performing argon ion polishing treatment, a rock sample with a more smooth and flat observation surface and clear pores under the scanning electron microscope can be obtained compared to a rock sample obtained by only performing a single polishing treatment on the rock, thereby improving the observation and research effect of the scanning electron microscope on the rock sample. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A flowchart of a rock sample preparation method for a scanning electron microscope is provided for embodiments of the present disclosure.

[0024] Figure 2 A flowchart of a rock sample preparation method for a scanning electron microscope is provided for embodiments of the present disclosure.

[0025] Figure 3 A schematic diagram of argon ion polishing is provided for embodiments of the present disclosure.

[0026] Figure 4 A structural diagram of a semi-inlaid embedding process is provided for embodiments of the present disclosure.

[0027] Figure 5 A schematic diagram of argon ion polishing is provided for embodiments of the present disclosure.

[0028] Figure 6 Argon ion polishing parameters are provided for embodiments of the present disclosure.

[0029] Figure 7 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0030] Figure 8 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0031] Figure 9 A flowchart of a rock sample preparation method for a scanning electron microscope is provided for embodiments of the present disclosure.

[0032] Figure 10 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0033] Figure 11 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0034] Figure 12 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0035] Figure 13 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0036] Figure 14 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0037] Figure 15 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure.

[0038] Figure 16 A schematic diagram of a scanning electron microscope image is provided for embodiments of the present disclosure. DETAILED DESCRIPTION

[0039] In order to make the purposes, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the drawings, and the described embodiments should not be regarded as limitations on the present disclosure. All other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present disclosure.

[0040] In the following description, "some embodiments" are referred to, which describe a subset of all possible embodiments, but it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0041] In the following description, the terms "first\second\third" are only to distinguish similar objects, and do not represent a specific order of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence as allowed, so that the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms used herein are only for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure.

[0043] In order to better understand the embodiments of the present disclosure, the following will be described through some scene embodiments:

[0044] In one embodiment, the rock sample can include a shale sample. Shale gas exists in shale, which is a natural gas resource with large storage capacity, wide application and high economic value. The exploration and development of shale gas is becoming more and more extensive. Shale gas is usually stored in the pores and cracks of shale. It is crucial to observe and study the microstructure and composition of shale inside through scanning electron microscopy in the process of exploration and development.

[0045] Shale has the characteristics of being easy to break and easy to fall off, and the pores in shale are mostly nanoscale pores, so it is difficult to prepare shale samples with large scanning area and high imaging quality for scanning electron microscopy.

[0046] In one embodiment, the conventional rock sample preparation method for scanning electron microscopy includes: obtaining a rock sample with a required surface and size; deoiling the rock sample; fixing the rock sample; coating the rock sample to obtain a rock sample for scanning electron microscopy.

[0047] In one embodiment, the rock sample preparation method for scanning electron microscopy further includes: a mechanical polishing method and an argon ion polishing method.

[0048] In one embodiment, the mechanical polishing method can include: cutting and shaping the rock to obtain a predetermined volume of rock; bulk embedding the predetermined volume of rock; mechanically grinding and polishing the embedded rock by sandpaper; coating the polished rock to obtain a rock sample for scanning electron microscopy.

[0049] In one embodiment, the argon ion polishing method can include: cutting and shaping the rock to obtain a predetermined volume of rock; argon ion polishing the predetermined volume of rock; coating the polished rock to obtain a rock sample for scanning electron microscopy.

[0050] As shown in Figure 1 The present disclosure provides a rock sample preparation method for scanning electron microscopy, which comprises:

[0051] Step S101: mechanically grinding and polishing the rock;

[0052] Step S102: argon ion polishing the mechanically ground and polished rock;

[0053] Step S103: coating the argon ion polished rock to obtain a rock sample; wherein the rock sample is used for scanning electron microscopy.

[0054] In one embodiment, the type of rock can include shale, loose sandstone, dense sandstone, or carbonate rock, etc.

[0055] In one embodiment, the mechanical grinding and polishing process in step S101 can include mechanical grinding and mechanical polishing. In actual application, the rock may have problems such as uneven thickness, uneven rock observation surface, foreign matter on the rock observation surface, and / or stress damage on the rock observation surface, which is not conducive to scanning electron microscopy observation of the rock sample. The mechanical grinding and polishing process can solve or alleviate these problems.

[0056] In one embodiment, the argon ion polishing process in step S102 can include ionizing argon gas to produce argon ions by high-voltage electric field; polishing the rock sample surface by high-speed bombardment of the argon ions under the action of acceleration voltage. For example, a schematic diagram of polishing the rock sample surface by high-speed bombardment of the argon ion gun is shown in Figure 3

[0057] In this way, the stress damage layer can be removed by argon ion polishing, making the rock observation more smooth and flat, further displaying the nanoscale and / or micrometer scale pores of the rock sample to the scanning electron microscope, and increasing the observation and analysis effect of the rock sample. ​

[0058] In one embodiment, the coating treatment in the step S103 can include spraying a conductive film on the rock surface. Since the conductivity of the rock is often weak, the sample observed by the scanning electron microscope needs to have a certain conductivity. By spraying a conductive film on the rock surface, the rock sample can be clearly imaged under the scanning electron microscope.

[0059] Here, compared with the method of manufacturing a rock sample by only single mechanical polishing, the polishing effect of nanoscale can be obtained by the argon ion polishing treatment, and the stress damage caused by the mechanical polishing treatment can be removed, so that the rock observation surface is smoother and more flat, the effective observation surface area of the rock observation surface under the scanning electron microscope is larger, the nanoscale pores are clear, and the observation effect is better.

[0060] In the single argon ion polishing treatment, when there is a large damage or protrusion on the rock observation surface, the argon ion polishing parameters need to be adjusted multiple times for multiple argon ion polishing treatments. Therefore, compared with the single argon ion polishing treatment, the mechanical polishing treatment is performed first, and then the argon ion polishing treatment is performed, so that the efficiency of the polishing treatment is improved, and the flatness and smoothness of the rock observation surface are higher.

[0061] In some embodiments, the method further includes: before the mechanical polishing treatment of the rock, performing a half-embedded treatment on the rock with a predetermined volume.

[0062] In one embodiment, the rock obtained in reality often has a large size and cannot be directly observed by the scanning electron microscope. The rock can be selected to have a characteristic region to be observed, and the rock with a predetermined volume can be obtained from the characteristic region to be observed.

[0063] In one embodiment, the rock with a predetermined volume can include a rock with a predetermined volume obtained by cutting and shaping. The rock with a predetermined volume can include a rock with a predetermined volume obtained by cutting and shaping in the characteristic region to be observed.

[0064] In one embodiment, the rock with a predetermined volume can include a rock with a volume within a predetermined volume range, and the predetermined volume range can be determined according to the volume of the sample table of the scanning electron microscope and / or the specific volume of the half-embedded mold. For example, the predetermined volume range can include a volume less than 30×30×10 cubic millimeters, a volume less than 25×25×5 cubic millimeters, or a volume less than 10×10×10 cubic millimeters, etc.

[0065] In one embodiment, the rock can be a block or sheet rock, and the predetermined volume range can be determined according to the rock observation surface area and the rock height. For example, the height of the rock can be less than 10 mm.

[0066] In one embodiment, the observation surface area of the rock sample is usually no more than 10 mm x 10 mm, and in the embodiments of the present disclosure, the observation surface area of the rock sample can be in the range of 10 mm x 10 mm to 25 mm x 25 mm. In this way, the observation surface area of the rock sample is larger, and the effect of scanning electron microscope analysis is better, and the analysis result obtained is more accurate compared with a rock sample with a small observation surface.

[0067] In one embodiment, the inlaid embedding process can completely inlay the rock into the embedding agent, which can protect the rock and reduce rock fragmentation during grinding and polishing. In the embodiments of the present disclosure, the semi-inlaid embedding process can inlay the rock into the embedding agent, and the stacking surface of the embedding agent is lower than the observation surface of the rock. In this way, compared with the complete inlaid embedding process, the semi-inlaid embedding process can protect the rock and reduce rock fragmentation, and at the same time, since there is no embedding agent on the observation surface of the rock, the confusion of the embedding agent to the observation and analysis of the rock sample under the scanning electron microscope can be reduced, and the efficiency and accuracy of the scanning electron microscope analysis of the rock sample are improved.

[0068] In some embodiments, the semi-inlaid embedding process of the rock with a predetermined volume includes:

[0069] Step S201: adding the embedding agent into the semi-inlaid embedding mold;

[0070] Step S202: placing the rock with a predetermined volume into the semi-inlaid embedding mold;

[0071] Step S203: continuing to add the embedding agent into the semi-inlaid embedding mold until the distance between the stacking surface of the embedding agent and the observation surface of the rock is within a preset range.

[0072] In one embodiment, the type of the embedding agent can be an epoxy resin embedding agent. The epoxy resin embedding agent can include epoxy resin and curing agent, etc. For example, the model of the epoxy resin embedding agent can include Eponate 812 embedding agent, Eponate 12 embedding agent, or Spurr resin embedding agent, etc.

[0073] In one embodiment, the method of obtaining the epoxy resin embedding agent can include: first mixing the epoxy resin and the curing agent in a predetermined ratio and stirring uniformly, and then standing to remove bubbles to obtain the embedding agent.

[0074] In one embodiment, the method can include: before adding the embedding agent into the semi-inlaid embedding mold, pretreating the semi-inlaid embedding mold.

[0075] In one embodiment, the pretreatment may include: cleaning the semi-embedded embedding mold; uniformly applying a release agent to the mold; and drying the mold. This pretreatment allows the semi-embedded rock to be easily detached from the mold, improving the efficiency of the semi-embedded embedding process.

[0076] In one embodiment, step S202 may include: determining the rock observation face of the predetermined volume of rock, and placing the rock observation face upward into the semi-mounted embedding mold.

[0077] In one embodiment, step S203 may include: adding the embedding agent from the edge of the mold until the distance between the accumulation surface of the embedding agent and the observation surface of the rock is within a preset range.

[0078] In one embodiment, such as Figure 4 As shown, the distance between the embedding surface and the rock observation surface is within a preset range, which may include: the embedding surface being lower than the rock observation surface, and the distance between the embedding surface and the rock observation surface being within a predetermined range. For example, the predetermined range may include: between 1 millimeter (mm) and 2 millimeters, or between 1 millimeter and 3 millimeters, etc.

[0079] In one embodiment, the method further includes: after step S203, performing a curing treatment on the rock semi-embedded by the embedding agent, i.e., curing the embedding agent according to a predetermined time range and a predetermined temperature range. For example, the curing treatment within the predetermined time range and predetermined temperature range may include: curing at room temperature (25 degrees Celsius) for 12 hours and / or curing at a temperature range of 30 to 60 degrees Celsius for 12-24 hours, etc.

[0080] In one embodiment, the process of semi-embedded embedding of a predetermined volume of rock may include: obtaining an epoxy resin embedding agent; pre-treating the rock according to the semi-embedded embedding mold; casting the rock in the semi-embedded embedding mold using the embedding agent; and curing the cast rock. Specifically, casting the rock in the semi-embedded embedding mold using the embedding agent includes: adding the embedding agent to the semi-embedded embedding mold; placing the predetermined volume of rock into the semi-embedded embedding mold; and continuing to add the embedding agent to the semi-embedded embedding mold until the distance between the accumulation surface of the embedding agent and the observation surface of the rock is within a preset range.

[0081] Here, through the half-inlay embedding treatment of the packing surface of the embedding agent lower than the rock observation surface, compared with not carrying out any inlay embedding treatment, the rock sample can be protected by the embedding agent, the rock sample can be reduced in the grinding and polishing treatment, and the efficiency of preparing the rock sample is improved; meanwhile, since the epoxy resin embedding agent contains element components such as carbon C, hydrogen H, oxygen O and nitrogen N, which are similar to the organic matter components of the rock, compared with the inlay embedding of the embedding agent wrapping the rock observation surface, the confusion of the epoxy resin embedding agent to the rock sample under the scanning electron microscope can be reduced, the quality of the rock sample is improved, and the accuracy of the scanning electron microscope in analyzing and researching the rock sample is improved.

[0082] In some embodiments, the mechanical grinding and polishing treatment comprises:

[0083] coarse grinding treatment on the rock;

[0084] fine grinding treatment on the rock after the coarse grinding treatment;

[0085] mechanical polishing treatment on the rock after the fine grinding treatment.

[0086] In one embodiment, the granularity of the abrasive of the coarse grinding treatment can be greater than the granularity of the abrasive of the fine grinding treatment, and the granularity of the abrasive can be the fineness of the abrasive particles.

[0087] In one embodiment, the coarse grinding treatment on the rock can comprise leveling the rock after the half-inlay embedding treatment. Wherein, the leveling can remove the protrusions on the surface of the rock through grinding treatment, and make the rock observation surface parallel to the bottom surface of the rock sample, i.e. the opposite surface of the rock observation surface. Wherein, the leveling can comprise leveling the bottom surface of the rock sample and leveling the rock observation surface.

[0088] In one embodiment, the method can comprise coarse grinding treatment and fine grinding treatment on the rock according to the sandpaper.

[0089] In one embodiment, the coarse grinding treatment and fine grinding treatment on the rock according to the sandpaper can comprise coarse grinding treatment on the rock by sandpaper with smaller mesh number, and fine grinding treatment on the rock by sandpaper with mesh number greater than that of the sandpaper for coarse grinding treatment. The model of the sandpaper is represented by mesh number, which represents the fineness of the abrasive of the sandpaper and the number of mesh holes per square inch of area, and the higher the mesh number, the more mesh holes and the finer the abrasive. Commonly used sandpaper models can include 80 mesh, 100 mesh, 280 mesh, 400 mesh, 600 mesh, etc., and fine sandpaper models can include 800 mesh, 1000 mesh, 1200 mesh, 1500 mesh, 2000 mesh, 2500 mesh, 4000 mesh, etc. Wherein, the European sandpaper adds P before the mesh number.

[0090] For example, the method can include: rough grinding and leveling the rock observation surface by P500 sandpaper, rough grinding by P1200 sandpaper and P2500 sandpaper, and fine grinding by P4000 sandpaper.

[0091] In one embodiment, the mechanical polishing process can include: mechanically polishing the rock observation surface according to a polishing liquid and a polishing cloth. The polishing liquid can include an alumina suspension polishing liquid, a silicon oxide suspension polishing liquid, a silicon carbide suspension polishing liquid, or a diamond suspension polishing liquid, etc.

[0092] In one embodiment, the method further includes: during the mechanical grinding and polishing process, observing the state of the rock sample observation surface by a microscope at a predetermined time interval. In this way, compared with not observing the state of the rock observation surface during the mechanical grinding and polishing process, the process can be adjusted in time according to the state of the rock surface during the mechanical grinding and polishing process, thereby improving the grinding and polishing effect of the rock observation surface. The stress generated by the mechanical grinding and polishing process is generally in the range of 5-10N, and the generated stress is relatively large, which can damage the rock observation surface and cause the rock sample observation surface to crack and fall off. By observing the state of the rock observation surface at a predetermined time interval, the cracking and falling off of the rock observation surface can be reduced.

[0093] In some embodiments, the argon ion polishing process includes:

[0094] Adjusting the height of the rock observation surface so that the rock observation surface can be used for polishing;

[0095] Polishing the rock by argon ion polishing equipment according to predetermined polishing parameters.

[0096] In one embodiment, the method can include: polishing the rock by argon ion polishing equipment. The polishing of the rock by argon ion polishing equipment can include: placing the rock in a sample stage of the argon ion polishing equipment; adjusting the height of the rock observation surface by the sample stage to determine that the argon ion polishing process can act on the rock observation surface; and polishing the rock by argon ion polishing according to predetermined polishing parameters.

[0097] In one embodiment, the method further includes: during the argon ion polishing process, observing the state of the rock sample observation surface by a microscope at a predetermined time interval. In this way, compared with not observing the state of the rock sample observation surface, the parameters of the argon ion polishing can be adjusted in time according to the state of the rock observation surface, thereby improving the effect of the argon ion polishing.

[0098] In some embodiments, the polishing of the rock by argon ion polishing according to predetermined polishing parameters includes:

[0099] polish the rock by argon ions of a first voltage;

[0100] polish the rock polished by argon ions of the first voltage by argon ions of a second voltage, wherein the second voltage is lower than the first voltage.

[0101] In one embodiment, the rock is first polished by argon ions of a first voltage, and then polished by argon ions of a second voltage. The high voltage of the first voltage can make the energy of the argon ion beam higher, so that the observation surface of the rock can be quickly polished. The low voltage of the second voltage can make the energy of the argon ion beam more gentle, so that the damage caused by the polishing of the first voltage can be finely repaired, and a rock sample with high flatness and clear imaging under a scanning electron microscope can be obtained.

[0102] In some embodiments, the film coating process comprises:

[0103] The rock is vacuum-coated according to predetermined film coating parameters.

[0104] In one embodiment, the film coating parameters can include the type of conductive film, the film coating thickness, the film coating vacuum degree, the film coating time, and / or the film coating current, etc.

[0105] In one embodiment, the type of conductive film can include a gold conductive film, a copper conductive film, a carbon conductive film, or a carbon-gold double-layer conductive film, etc.

[0106] In some embodiments, the predetermined polishing parameters can include voltage, current, polishing time, the number of ion guns, and / or the angle of ion guns, etc.

[0107] In one embodiment, the angle of the ion gun can be the angle between the argon ion beam and the observation surface of the rock. The smaller the angle of the ion gun, the larger the polishing area.

[0108] In one embodiment, the number of ion guns is usually one or two. In the embodiment of the present disclosure, as shown in Figure 5 the number of ion guns can be three. The area of the ion beam generated by the combination of three ion guns is larger. By adjusting the distance between the three ion guns, the activity range of the ion beam generated by the three ion guns can be larger. Therefore, compared with one or two ion guns, three ion guns can be used to polish a rock with a larger observation surface, and the results obtained by observing and studying a larger rock sample under a scanning electron microscope are more accurate.

[0109] In one embodiment, as shown in Figure 6As shown, the method further comprises: performing a first argon ion polishing treatment on the rock sample by an argon ion gun with a first voltage and a first ion gun angle for a first polishing duration; and performing a second argon ion polishing treatment on the rock sample by an argon ion gun with a second voltage and a second ion gun angle for a second polishing duration, wherein the second voltage is lower than the first voltage, the second polishing duration is shorter than the first polishing duration, and the second ion gun angle is lower than the first ion gun angle.

[0110] In this way, in the first argon ion polishing treatment, high voltage, high argon ion gun angle and long polishing duration can make the intensity of the argon ion beam higher and the depth deeper, so that the stress damage layer of the rock observation surface can be quickly and large-area removed. Low voltage, low argon ion gun angle and short polishing duration can be used to repair the damage caused by the first argon ion polishing treatment. Through the combination of the first argon ion polishing treatment and the second argon ion polishing treatment, a large-area and more smooth observation surface of the rock sample can be obtained.

[0111] In some embodiments, the method further comprises: obtaining a rock with a predetermined volume by cutting and shaping treatment.

[0112] In one embodiment, the obtaining a rock with a predetermined volume by cutting and shaping treatment can comprise: determining a rock sample area to be cut according to a predetermined volume range; and cutting the rock sample area by a diamond cutting line according to predetermined cutting parameters to obtain a rock within the predetermined volume range. The cutting of the rock sample by the diamond cutting line can comprise: generating a cutting action by rapid reciprocating motion of the diamond cutting line.

[0113] In one embodiment, the predetermined cutting parameters can comprise: cutting speed and / or cutting step, etc.

[0114] In some embodiments, the method further comprises:

[0115] After the mechanical grinding and polishing treatment of the half-mount embedding treated rock, the mechanically ground and polished rock is subjected to cleaning and drying treatment.

[0116] In one embodiment, the cleaning and drying treatment can comprise cleaning treatment and drying treatment.

[0117] In one embodiment, the cleaning treatment can comprise ultrasonic oscillation cleaning of the rock. The ultrasonic oscillation cleaning can comprise ultrasonic oscillation cleaning of the rock in an ultrasonic cleaning agent by an ultrasonic instrument. The ultrasonic cleaning agent can comprise a water-based cleaning agent or a chemical solvent, etc. For example, the ultrasonic cleaning agent can be an alcohol solvent.

[0118] In one embodiment, the cleaning process can remove foreign matter present on the rock observation surface, which can include mechanical polishing liquid or rock debris or dust generated by grinding and polishing, and can improve the accuracy and efficiency of the observation and analysis of the rock sample observation surface under the scanning electron microscope compared to the case where the cleaning process is not performed. Figure 7

[0119] When the mechanical polishing liquid is an alumina polishing liquid, the size of the individual alumina can be between 50 nm and 60 nm, and an alumina aggregate can also be formed in the alumina polishing liquid, and the size of the alumina aggregate can be between 400 nm and 2000 nm. The scanning electron microscope image of the alumina polishing liquid remaining on the rock observation surface can be as shown in Figure 8

[0120] In one embodiment, the drying process can include drying the cleaned rock. The drying process can remove water and other substances from the rock, which can reduce the influence of water evaporation on the observation and analysis of the rock sample under the scanning electron microscope.

[0121] In one embodiment, as shown in Figure 9 A method for preparing a rock sample for a scanning electron microscope can include the following steps:

[0122] Step S1, obtaining a rock of a predetermined volume through cutting and shaping;

[0123] Step S2, performing a half-embedded embedding process on the rock of the predetermined volume;

[0124] Step S3, performing a mechanical grinding and polishing process on the half-embedded embedded rock;

[0125] Step S4, performing a cleaning process on the mechanically ground and polished rock;

[0126] Step S5, performing a drying process on the cleaned rock;

[0127] Step S6, performing an argon ion polishing process on the dried rock;

[0128] Step S7, performing a film plating process on the argon ion polished rock to obtain a rock sample;

[0129] Step S8, observing the rock sample under a scanning electron microscope.

[0130] The embodiments of the present disclosure provide a rock sample preparation system for a scanning electron microscope, which includes: ​​

[0131] A mechanical lapping and polishing device for performing a mechanical lapping and polishing process on a predetermined volume of rock after a semi-mounting embedding process;

[0132] An argon ion polishing device for performing an argon ion polishing process on the rock after the mechanical lapping and polishing process;

[0133] A coating device for performing a coating process on the rock after the argon ion polishing process to obtain a rock sample; wherein the rock sample is used for scanning electron microscopy.

[0134] In one embodiment, the model of the mechanical lapping and polishing device can include: Saphir 250A2-ECO of Odel Magni QATM.

[0135] In one embodiment, the mechanical lapping and polishing process performed by the mechanical lapping and polishing device can include: determining that the mechanical lapping and polishing device meets normal working conditions, wherein the determining that the mechanical lapping and polishing device meets normal working conditions can include: determining that the air compressor pressure meets normal working conditions and / or determining that the water system meets normal working conditions, etc.; performing a mechanical lapping and leveling process on the epoxy resin of the bottom surface of the predetermined volume of rock after the semi-mounting embedding process by P180 sandpaper; performing a mechanical lapping and leveling process on the observation surface of the predetermined volume of rock after the semi-mounting embedding process by P500 sandpaper to make the observation surface of the rock parallel to the bottom surface; performing a mechanical coarse grinding process on the observation surface of the rock by P1200 sandpaper; performing a mechanical coarse grinding process on the observation surface of the rock by P2500 sandpaper; performing a mechanical fine grinding process on the observation surface of the rock by P4000 sandpaper; and performing a mechanical polishing process on the observation surface of the rock by an aluminum oxide suspension and a polishing cloth.

[0136] In one embodiment, the model of the argon ion polishing device can include: EM TIC 3X three-beam argon ion polisher of Leica LEICA.

[0137] In one embodiment, the argon ion polishing process performed on the rock after the mechanical lapping and polishing process by the argon ion polishing device can include:

[0138] Determining that the argon ion polishing device meets normal working conditions, wherein the determining that the argon ion polishing device meets normal working conditions can include: determining that the argon gas pressure meets normal working conditions and / or determining that the sample stage meets normal working conditions, etc.

[0139] Placing the rock after the mechanical lapping and polishing process into the sample stage; height calibrating the height of the observation surface of the rock according to the sample stage to determine that the argon ion polishing process can act on the observation surface of the rock;

[0140] setting a predetermined polishing parameter in the argon ion polisher; polishing the rock observation surface by the argon ion polisher according to the predetermined polishing parameter; and observing the polishing state of the rock observation surface by the body microscope in the argon ion polisher.

[0141] In one embodiment, the model of the coating equipment can include EM ACE200 of LEICA.

[0142] In one embodiment, the coating treatment of the rock polished by the argon ion polisher by the coating equipment can include:

[0143] determining that the coating equipment meets the normal working condition, wherein the determination that the coating equipment meets the normal working condition can include confirming that the vacuum pump meets the normal working condition and / or determining that the material content of the conductive film, such as carbon wire, meets the normal working condition;

[0144] placing the rock in the sample stage of the coating equipment; height calibrating the height of the rock observation surface to determine that the quartz vibration piece can measure the coating thickness of the rock observation surface; setting a predetermined coating parameter; and coating the rock observation surface under vacuum condition according to the predetermined coating parameter.

[0145] In one embodiment, the system can further include: before the mechanical grinding and polishing treatment of the rock, performing a half-embedded treatment on a rock of a predetermined volume.

[0146] In one embodiment, the rock sample preparation system further includes: a cutting and shaping device for obtaining a rock of a predetermined volume by cutting and shaping treatment. For example, the cutting and shaping device can include a desktop core fine machining device of Beiyuan Technology.

[0147] In one embodiment, the cutting and shaping treatment by the cutting and shaping device to obtain a rock of a predetermined volume can include:

[0148] determining that the cutting device meets the normal working condition, wherein the determination that the cutting device meets the normal working condition can include determining that the content of the cooling circulating water can meet the working requirement, determining that the water pump can work normally, and / or determining that water can be added dropwise to the diamond cutting line, etc.

[0149] placing the rock sample to be cut on the sample clamp in the cutting and shaping device and fixing it; confirming the rock sample area to be cut and the cutting path; setting a predetermined cutting parameter, such as cutting rotation speed and cutting step; and cutting the rock sample area to be cut by the diamond cutting line according to the predetermined cutting parameter to obtain a rock of a predetermined volume.

[0150] In one embodiment, the rock sample preparation system further comprises: a scanning electron microscope device for observing the rock sample by scanning electron microscope. Exemplarily, the model of the scanning electron microscope device can include Helios 5CX of ThermoFisher Scientific.

[0151] In one embodiment, the observation of the rock sample by scanning electron microscope can include: placing the rock sample into a sample chamber of the scanning electron microscope; adjusting the sample chamber to a vacuum state; setting scanning electron microscope parameters; observing a rock sample observation surface by scanning electron microscope to confirm whether the imaging quality of the rock observation surface meets the requirements; when the imaging quality of the rock sample observation surface meets the requirements, collecting an image of the rock sample observation surface.

[0152] In one embodiment, the observation of the rock sample observation surface by scanning electron microscope to confirm whether the imaging quality of the rock observation surface meets the requirements can include:

[0153] Observing, by a secondary electron image of the scanning electron microscope, whether there are scratches caused by mechanical polishing and directional polishing marks caused by argon ion polishing treatment on the rock sample observation surface; exemplarily, the scratches can be as shown in Figure 10 , and the directional polishing marks can be as shown in Figure 11 ;

[0154] Observing, by a secondary electron image and a backscattered image of the scanning electron microscope, whether there are foreign matters on the rock sample observation surface, wherein the foreign matters can include dust and aluminum oxide suspension; exemplarily, an image with dust can be as shown in Figure 7 , and an image with aluminum oxide suspension can be as shown in Figure 8 ;

[0155] Observing, by a secondary electron image and a backscattered image of the scanning electron microscope, whether there are shedding phenomena on the rock sample observation surface. Exemplarily, an image with shedding phenomena can be as shown in Figure 12 , and an image without shedding phenomena can be as shown in Figure 13 ;

[0156] Observing, by a secondary electron image and a backscattered image of the scanning electron microscope, whether there are charging effects on the rock sample observation surface, which can be that, under the action of an electron beam, a sample surface with poor conductivity performance will accumulate a certain negative charge. When there is a charging effect, the backscattered image can show local abnormal brightening or image refreshing drift or jitter phenomenon. Exemplarily, an image with charging effect can be as shown in Figure 14 .

[0157] In one embodiment, the collecting the rock sample observation face image can include: collecting images according to typical features and special features in the rock sample observation face image, the features can include minerals, pores, cracks, and / or organic matter, and the like two-dimensional structural features, and the collected images can represent the typical and special two-dimensional structural features and the mutual relationship between the features. For example, the image of the organic matter pore can be as shown in FIG. 8, and the image of the micro crack can be as shown in FIG. 9. Figure 15 Figure 16

[0158] It should be noted that those skilled in the art can understand that the method provided by the embodiments of the present disclosure can be executed alone or together with some methods in some methods or related technologies in the embodiments of the present disclosure.

[0159] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure, which should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.​​

Claims

1. A method for rock sample preparation for scanning electron microscopy, characterized by, The method comprises: adding an embedding agent into a half-inlay embedding mold; putting a rock with a predetermined volume into the half-inlay embedding mold; the embedding agent is an epoxy embedding agent; continuing to add the embedding agent into the half-inlay embedding mold until a stacking surface of the embedding agent is lower than an observation surface of the rock, and a distance between the stacking surface and the observation surface is within a preset range; performing a mechanical grinding and polishing treatment on the rock; performing an argon ion polishing treatment on the rock after the mechanical grinding and polishing treatment; performing a film coating treatment on the rock after the argon ion polishing treatment to obtain a rock sample; the rock sample is used for a scanning electron microscope. The argon ion polishing treatment comprises: performing an argon ion polishing treatment on the rock by argon ions with a first voltage; performing an argon ion polishing treatment on the rock after the argon ion polishing treatment by argon ions with a first voltage by argon ions with a second voltage; the second voltage is lower than the first voltage.

2. The method of claim 1, wherein, The mechanical grinding and polishing treatment comprises: performing a coarse grinding treatment on the rock; performing a fine grinding treatment on the rock after the coarse grinding treatment; performing a mechanical polishing treatment on the rock after the fine grinding treatment.

3. The method of claim 1, wherein, The method further comprises: adjusting a height of the observation surface of the rock so that the observation surface can be used for polishing treatment.

4. The method of claim 1, wherein, The film coating treatment comprises: performing a vacuum film coating treatment on the rock according to predetermined film coating parameters.

5. The method of claim 3, wherein, The predetermined polishing parameters comprise at least one of: a voltage; a current; a polishing time length; a number of ion guns; an angle of the ion guns.

6. The method of claim 1, wherein, The method further comprises: obtaining the rock with the predetermined volume by cutting and shaping treatment.

7. The method of claim 1, wherein, The method further comprises: performing a cleaning and drying treatment on the rock after the mechanical grinding and polishing treatment.

8. A rock sample preparation system for a scanning electron microscope, characterized by, The system comprises: a mechanical grinding and polishing device for performing a mechanical grinding and polishing treatment on a rock with a predetermined volume after half-inlay embedding treatment; a stacking surface of an embedding agent in the rock with the predetermined volume after the half-inlay embedding treatment is lower than an observation surface of the rock, and a distance between the stacking surface and the observation surface is within a preset range; the embedding agent is an epoxy embedding agent; an argon ion polishing device for performing an argon ion polishing treatment on the rock by argon ions with a first voltage, and performing an argon ion polishing treatment on the rock after the argon ion polishing treatment by argon ions with a first voltage by argon ions with a second voltage; the second voltage is lower than the first voltage; a film coating device for performing a film coating treatment on the rock after the argon ion polishing treatment to obtain a rock sample; the rock sample is used for a scanning electron microscope.

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