Ball mill for measuring TOC (total organic carbon) of black clay shale hydrocarbon source rock

Abstract

The invention discloses a ball mill for measuring TOC of black clay shale hydrocarbon source rock, and relates to the technical field of ball mills for experiments, the ball mill comprises a grinding bin, a glass plate is fixed on one side of the grinding bin, and the glass plate is used for observing the operation condition in the grinding bin; the opening and closing frame is arranged above the grinding bin in a sliding mode and ascends and descends through a driving cylinder body; the display screen is mounted on the opening and closing frame; the lifting assembly is fixed in the opening and closing frame; the sealing assembly is mounted in the grinding bin and corresponds to the lifting assembly; and at least air source equipment and a circulating pump are installed in the grinding bin, the air source equipment is used for providing and storing cooling air, and the circulating pump is used for conveying the cooling air into the closed assembly for circulation.

Description

Technical Field

[0001] This invention relates to the field of experimental ball mill technology, specifically a ball mill for determining the TOC of black mudstone and shale source rocks. Background Technology

[0002] Total organic carbon (TOC) content is a core indicator for evaluating the hydrocarbon generation potential of source rocks. Before TOC determination, rock samples need to be ground into a uniform fine powder (usually requiring a mesh size of 200 or higher) to ensure the removal of inorganic carbon through subsequent acid treatment and the accuracy and representativeness of instrument measurements. Currently, planetary ball mills or vibratory ball mills are commonly used in laboratories for this sample pretreatment. Existing ball mills typically consist of a power system, transmission mechanism, grinding platform (or jar base), and grinding jar. Their operation involves placing the sample to be ground along with grinding balls (such as steel balls or tungsten carbide balls) into the grinding jar. The sample is then pulverized through the high-speed revolution and rotation of the grinding platform (planetary ball mill) or high-frequency vibration (vibratory ball mill), utilizing the impact and friction between the grinding balls and the jar wall, and between the grinding balls themselves.

[0003] Existing planetary ball mills are difficult to clean thoroughly when changing samples, which can easily lead to cross-contamination of samples and affect the measurement results. Furthermore, the use of grinding balls of various sizes during grinding can result in both over-grinding and under-grinding. In addition, a large amount of local impact heat and frictional heat are generated during high-speed grinding, which causes the temperature inside the grinding jar to rise significantly. This thermal effect may cause some light hydrocarbons and volatile organic matter in the source rock to escape or pyrolyze, resulting in a systematically low TOC measurement value.

[0004] To address the above problems, this invention provides a ball mill for measuring the TOC of black mudstone and shale source rocks, thereby solving the aforementioned issues. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides the following technical solution: a ball mill for determining the TOC of black mudstone and shale source rocks, comprising:

[0006] The grinding chamber has a glass plate fixed to one side for observing the operation inside the grinding chamber.

[0007] The opening and closing frame is slidably disposed above the grinding chamber and is raised and lowered by a drive cylinder;

[0008] The display screen is mounted on the opening and closing frame;

[0009] The lifting assembly is fixed inside the opening and closing frame;

[0010] A closed assembly is installed inside the grinding chamber and corresponds to the lifting assembly;

[0011] Furthermore, the grinding chamber is equipped with at least an air source device and a circulation pump. The air source device is used to provide and store cooling gas, and the circulation pump is used to circulate the cooling gas into the enclosed assembly.

[0012] Further, preferably, the lifting assembly includes:

[0013] The lifting cylinder is fixed inside the conveyor opening and closing frame;

[0014] A fixed column is fixed to the output end of the lifting cylinder.

[0015] An air inlet is provided on the side wall of the fixed column and is connected to the air source equipment via the circulating pump.

[0016] A rotating disk is coaxially rotatably mounted on the lower end face of the fixed column;

[0017] Four rotating columns are configured to rotate circumferentially on the lower end face of the rotating disk;

[0018] A sealing disc is fixed to the lower end face of the rotating column.

[0019] Furthermore, preferably, an air inlet pipe is fixed through the axial position of the rotating disk, the upper end face of the air inlet pipe is connected to the air inlet by a rotary joint, a connecting disk is fixed to the lower end face of the air inlet pipe, and multiple connecting pipes are fixed to the circumference of the side wall of the connecting disk.

[0020] Furthermore, preferably, a pressing plate is fixed to the lower end face of the sealing disc, and a plurality of pressing posts are fixed to the lower end face of the pressing plate.

[0021] Further, preferably, the enclosure component includes:

[0022] A drive assembly is installed inside the grinding chamber, and a drive motor is fixed inside the grinding chamber;

[0023] The outer chamber is fixed to the upper end face of the drive assembly and is sealed to the lifting assembly;

[0024] The base plate is rotatably mounted on the drive assembly;

[0025] The grinding components are configured in four parts, all of which are rotatably mounted on the base plate and are opened and closed by the lifting components.

[0026] Further, preferably, the driving component includes:

[0027] A retaining ring is fixed inside the grinding chamber, and an internal gear ring is fixed to its inner wall;

[0028] The sun gear is rotatably positioned at the axial center of the fixed ring and connected to the output end of the drive motor;

[0029] The planetary teeth are configured in four and mesh with the inner gear ring and the sun gear. The base plate is fitted on the four planetary teeth, and the four planetary teeth correspond one-to-one with the four grinding components.

[0030] Further, preferably, the grinding assembly includes:

[0031] The mounting plate is fixed at the axis of the planetary gear, and multiple positioning pins are fixed on its upper end face.

[0032] The outer cylinder is fixed to the outer wall of the mounting plate;

[0033] The inner cylinder is detachably mounted on the mounting plate and is positioned using multiple positioning pins.

[0034] A closed ring is fixed to the inner wall of the outer cylinder and is located away from the mounting plate;

[0035] A circulation chamber is located between the outer cylinder and the inner cylinder;

[0036] A circulation component is installed on the outer wall of the outer cylinder and is connected to the lifting component;

[0037] The grading component is installed inside the inner cylinder and away from the mounting plate.

[0038] Furthermore, preferably, the outer cylinder has multiple through holes at positions corresponding to the circulation component, and the inner cylinder has multiple storage compartments at positions corresponding to the grading component.

[0039] Further, preferably, the circulation component includes:

[0040] An intake ring is embedded in and rotatably disposed on the outer wall of the outer cylinder;

[0041] The intake valve is fixed at the axial position of the intake ring near the base plate;

[0042] The exhaust valve is fixed at the axial position of the intake ring away from the base plate;

[0043] An annular cavity is formed between the intake ring and the outer cylinder.

[0044] Further, preferably, the hierarchical component includes:

[0045] Multiple curved plates are configured, all arranged at an angle, and slidably disposed in multiple storage compartments. A spring one or a spring two is disposed between the plate and the storage compartment. The spring one and spring two are arranged alternately, and the elasticity of the spring two is greater than that of the spring one.

[0046] A guide surface is formed on the lower end face of the arc-shaped plate;

[0047] The steel balls are configured in multiple ways, including steel ball one, steel ball two, and steel ball three. Steel ball one is placed directly into the inner cylinder, and steel ball two and steel ball three are placed alternately in the storage compartment. Steel ball two corresponds to spring one, and steel ball three corresponds to spring two. The steel balls are arranged in descending order of diameter as steel ball one, steel ball two, and steel ball three.

[0048] A barrier ring is slidably disposed inside the inner cylinder, and initially the storage compartment is closed by a barrier spring;

[0049] An inclined surface is formed on the upper end face of the barrier ring;

[0050] The discharge surface is formed on the inner wall of the barrier ring;

[0051] Multiple pressing elements are configured and circumferentially fixed to the inner wall of the barrier ring.

[0052] Compared with the prior art, the present invention provides a ball mill for measuring the TOC of black mudstone and shale source rocks, which has the following beneficial effects:

[0053] In this invention, the gas source device ensures that the entire grinding process is carried out in a low-temperature environment (e.g., <15°C), eliminating the negative impact of heat on organic matter. By evacuating the inner cylinder and filling it with inert gases such as high-purity nitrogen or argon, an oxygen-free environment is provided for the sample throughout the grinding process, preventing the oxidation of organic matter. Before grinding, a large-diameter steel ball is placed to coarsely crush the sample. Then, by increasing the grinding speed, a second steel ball is used for medium crushing. Finally, by increasing the grinding speed again, a third steel ball is used for fine grinding, effectively avoiding the problems of over-grinding and under-grinding. Furthermore, the detachable arrangement of the inner cylinder facilitates the installation of steel balls and the removal of samples, avoiding cross-contamination of samples. Attached Figure Description

[0054] Figure 1 A schematic diagram of the overall structure of a ball mill used for TOC determination in a black mudstone shale source rock;

[0055] Figure 2 A schematic diagram of the closed-system structure of a ball mill used for TOC determination in a black mudstone shale source rock;

[0056] Figure 3 This is a schematic diagram of a partially unfolded closed component of a ball mill used for TOC determination in a black mudstone source rock.

[0057] Figure 4 A schematic diagram of the grinding components of a ball mill used for TOC determination in a black mudstone source rock;

[0058] Figure 5for Figure 4 Enlarged structural diagram at point A in the middle;

[0059] Figure 6 for Figure 4 Enlarged structural diagram at point B;

[0060] In the diagram: 1. Grinding chamber; 2. Glass plate; 3. Opening / closing frame; 4. Display screen; 5. Lifting assembly; 6. Sealing assembly; 51. Fixed column; 52. Air inlet; 53. Rotating disc; 54. Air inlet pipe; 55. Connecting disc; 56. Connecting pipe; 57. Rotating column; 58. Sealing disc; 59. Pressing disc; 591. Pressing column; 61. Drive assembly; 62. Outer chamber; 63. Grinding assembly; 64. Base plate; 611. Fixed ring; 612. Sun gear; 613. Planetary gear 631. Gear; 632. Mounting plate; 633. Positioning pin; 633. Outer cylinder; 6331. Through hole; 634. Inner cylinder; 6341. Storage bin; 635. Sealing ring; 636. Circulation bin; 637. Circulation assembly; 6371. Inlet ring; 6372. Exhaust valve; 6373. Annular cavity; 6381. Arc plate; 6382. Guide surface; 6383. Steel ball; 6384. Barrier ring; 6385. Inclined surface; 6386. Discharge surface; 6387. Pressing component. Detailed Implementation

[0061] Reference Figures 1-6 This invention provides a technical solution: a ball mill for determining the TOC of black mudstone and shale source rocks, comprising:

[0062] The grinding chamber 1 has a glass plate 2 fixed on one side for observing the operation inside the grinding chamber 1.

[0063] The opening and closing frame 3 is slidably disposed above the grinding chamber 1 and is raised and lowered by a drive cylinder;

[0064] Display screen 4 is mounted on the opening and closing frame 3;

[0065] The lifting component 5 is fixed inside the opening and closing frame 3;

[0066] The sealing component 6 is installed inside the grinding chamber 1 and corresponds to the lifting component 5;

[0067] Furthermore, the grinding chamber 1 is equipped with at least an air source device and a circulation pump. The air source device is used to provide and store cooling gas, and the circulation pump is used to circulate the cooling gas into the enclosed assembly 6.

[0068] A temperature sensor can be installed inside the enclosed component 6 to monitor the grinding temperature in real time. The control system drives the circulation pump to ensure that the entire grinding process is carried out in a low-temperature environment (such as <15°C), eliminating the negative impact of heat on organic matter.

[0069] In this embodiment, the lifting assembly 5 includes:

[0070] The lifting cylinder is fixed inside the conveyor opening and closing frame 3;

[0071] The fixing column 51 is fixed to the output end of the lifting cylinder.

[0072] An air inlet 52 is provided on the side wall of the fixed column 51 and is connected to the air source equipment via the circulating pump.

[0073] The rotating disk 53 is coaxially rotatably disposed on the lower end face of the fixed column 51;

[0074] Four rotating columns 57 are configured to rotate circumferentially on the lower end face of the rotating disk 53;

[0075] The sealing disc 58 is fixed to the lower end face of the rotating column 57.

[0076] It should be noted that a gas valve is provided on the sealing plate 58, which is connected to the grinding component 63. The gas valve can be used to evacuate and fill the sample with inert gases such as high-purity nitrogen or argon, thereby providing an oxygen-free environment for the sample throughout the grinding process and preventing the oxidation of organic matter.

[0077] Preferably, an air inlet pipe 54 is fixed through the axial position of the rotating disk 53, the upper end face of the air inlet pipe 54 is connected to the air inlet 52 by a rotary joint, a connecting disk 55 is fixed to the lower end face of the air inlet pipe 54, and a plurality of connecting pipes 56 are fixed to the circumference of the side wall of the connecting disk 55.

[0078] In addition, a pressing plate 59 is fixed to the lower end face of the sealing plate 58, and a plurality of pressing posts 591 are fixed to the lower end face of the pressing plate 59.

[0079] In other words, the sealing disc 58 can rotate on its own axis and also revolve around the rotating disc 53, thereby cooperating with the movement of the sealing component 6 and avoiding excessive friction.

[0080] In this embodiment, the enclosing component 6 includes:

[0081] A drive assembly 61 is installed inside the grinding chamber 1, and a drive motor is fixed inside the grinding chamber 1;

[0082] The outer chamber 62 is fixed to the upper end face of the drive assembly 61 and is sealed to the lifting assembly 5;

[0083] The base plate 64 is rotatably mounted on the drive assembly 61;

[0084] The grinding components 63 are configured in four parts, all of which are rotatably mounted on the base plate 64 and are opened and closed by the lifting components 5.

[0085] It should be noted that during grinding, the rotating disk 53 is completely inserted into the outer chamber 62, and a sealing ring is provided on the outer wall of the rotating disk 53 to facilitate sealing operations.

[0086] In a preferred embodiment, the driving component 61 includes:

[0087] A retaining ring 611 is fixed inside the grinding chamber 1, and an internal gear ring is fixed on its inner wall;

[0088] The sun tooth 612 is rotatably mounted at the axial position of the fixed ring 611 and connected to the output end of the drive motor;

[0089] The planetary teeth 613 are configured in four and mesh with the inner gear ring and the sun tooth 612. The base plate 64 is sleeved on the four planetary teeth 613, and the four planetary teeth 613 correspond one-to-one with the four grinding components 63.

[0090] In other words, the drive component 61 is a planetary gear structure. Through the rotation of the sun gear 612, it can drive the planetary gear 613 to rotate on its own axis and revolve around the sun gear 612, thereby improving the grinding effect.

[0091] In a preferred embodiment, the grinding assembly 63 includes:

[0092] Mounting disk 631 is fixed at the axial position of planetary gear 613, and multiple positioning pins 632 are fixed on its upper end face;

[0093] The outer cylinder 633 is fixed to the outer wall of the mounting plate 631;

[0094] The inner cylinder 634 is detachably mounted on the mounting plate 631 and is positioned by a plurality of positioning pins 632;

[0095] A closing ring 635 is fixed to the inner wall of the outer cylinder 633 and is located away from the mounting plate 631;

[0096] The circulation chamber 636 is located between the outer cylinder 633 and the inner cylinder 634;

[0097] The circulation component 637 is installed on the outer wall of the outer cylinder 633 and is connected to the lifting component 5;

[0098] The grading component is installed inside the inner cylinder 634 and away from the mounting plate 631.

[0099] In addition, the outer cylinder 633 has multiple through holes 6331 at positions corresponding to the circulation component 637, and the inner cylinder 634 has multiple storage compartments 6341 at positions corresponding to the grading component.

[0100] It should be noted that the storage compartment 6341 has at least a horizontal placement surface and an inclined exit surface.

[0101] In a preferred embodiment, the circulation component 637 includes:

[0102] An intake ring 6371 is embedded in and rotatably disposed on the outer wall of the outer cylinder 633;

[0103] The intake valve is fixed at the axial position of the intake ring 6371 near the base plate 64;

[0104] The exhaust valve 6372 is fixed at the axial position of the intake ring 6371 away from the base plate 64;

[0105] An annular cavity 6373 is formed between the intake ring 6371 and the outer cylinder 633.

[0106] The intake valve is connected to the connecting pipe 56, and the diameter of the intake valve is larger than the diameter of the exhaust valve 6372. The cooling gas enters the circulation chamber 636 through the intake valve to perform temperature control on the inner cylinder 634 and complete the initial heat exchange. Then, it is discharged through the exhaust valve 6372 to the outer chamber 62 and multiple grinding components 63 to cool the grinding components 63 as a whole, avoiding frictional heat during long-term rotation. Furthermore, using the cooling gas after the initial heat exchange to cool the grinding components 63 as a whole can prevent the rotating parts from malfunctioning due to excessively low temperature.

[0107] In a preferred embodiment, the hierarchical component includes:

[0108] Multiple arc-shaped plates 6381 are configured, all of which are arranged at an angle and are slidably disposed in multiple storage compartments 6341. A spring one or a spring two is disposed between the plate and the storage compartment 6341. The spring one and the spring two are arranged alternately, and the elasticity of the spring two is greater than that of the spring one.

[0109] Guide surface 6382 is formed on the lower end surface of the arc-shaped plate 6381;

[0110] Steel balls 6383 are configured in multiple ways, including steel ball one, steel ball two, and steel ball three. Steel ball one is directly placed into the inner cylinder 634. Steel ball two and steel ball three are placed alternately in the storage compartment 6341. Steel ball two corresponds to spring one, and steel ball three corresponds to spring two. The diameters of the steel balls 6383 are arranged from large to small as steel ball one, steel ball two, and steel ball three.

[0111] The barrier ring 6384 is slidably disposed inside the inner cylinder 634, and the storage compartment 6341 is initially closed by a barrier spring.

[0112] An inclined surface 6385 is formed on the upper end surface of the barrier ring 6384;

[0113] The discharge surface 6386 is formed on the inner wall of the barrier ring 6384;

[0114] Multiple pressing elements 6387 are configured and circumferentially fixed to the inner wall of the barrier ring 6384.

[0115] It should be noted that the multiple pressing parts 6387 correspond one-to-one with the multiple pressing columns 591, and are staggered with the storage compartment 6341 to avoid obstructing the steel ball 6383. Furthermore, the inner cylinder 634 and the steel ball 6383 are both made of high-purity zirconium oxide or agate.

[0116] In other words, the grinding process is divided into three stages:

[0117] Coarse crushing stage: Start the drive motor and run it at a low speed. At this time, only the steel balls perform preliminary crushing of the sample under the circulation of inert atmosphere and cooling gas.

[0118] Medium crushing stage: Increase the grinding speed, and the increased centrifugal force causes steel ball 2 to overcome the elastic force of spring 1, push the corresponding arc plate, and release medium-sized steel ball 2 to participate in grinding, and carry out medium crushing.

[0119] Fine grinding stage: The rotation speed is increased to a higher set value again, so that the third steel ball overcomes the more elastic second spring and releases the small-sized third steel ball to perform final fine grinding on the sample. Throughout the process, the cooling gas continues to circulate to maintain a low temperature (<15°C) inside the chamber.

[0120] Before grinding, steel balls two and three are placed alternately in storage chamber 6341, while steel ball one is placed directly into inner cylinder 634. When lifting component 5 presses and slides pressing plate 59 downward, pressing column 591 presses pressing component 6387, thereby pushing barrier ring 6384 to slide, so that storage chamber 6341 is in the open state, facilitating the discharge of steel balls two and three.

[0121] The specific implementation includes the following steps:

[0122] Step 1: Sample loading and equipment preparation, raising the opening and closing frame 3 and the lifting assembly 5.

[0123] The sample to be ground and the largest diameter steel ball are placed into the inner cylinder 634 of the grinding assembly 63. The medium and small-sized steel balls are placed alternately into the storage compartments 6341 on the side wall of the inner cylinder 634. At this time, the blocking ring 6384 closes the storage compartments 6341 under the action of the blocking spring. Then, the inner cylinder 634 is installed onto the mounting plate 631 of the outer cylinder 633 through the positioning post 632.

[0124] Step 2: Establishing a sealed and inert environment. Close the opening and closing frame 3. The lifting cylinder of the lifting component 5 drives the fixed column 51 to embed and press the sealing disc 58 onto the outer chamber 62 of the sealing component 6, forming a sealed grinding chamber. Then, a vacuum is drawn into the inner cylinder 634, and then high-purity nitrogen or argon is filled in.

[0125] Step 3: Start the circulating cooling and graded grinding. Start the drive motor to drive the sun gear 612 to rotate. Through planetary gear transmission, drive the four grinding components 63 on the base plate 64 to revolve and rotate, completing the coarse crushing stage, medium crushing stage and fine grinding stage.

[0126] Step 4: Unloading. After grinding is completed, the drive motor stops, and the lifting cylinder of the lifting assembly 5 is controlled to release the sealing state of the sealing disc 58. Then the opening and closing frame 3 is opened. At this time, the blocking ring 6384 is reset by the blocking spring, and the inner cylinder 634 is taken out to pour out the sample.

[0127] Step 5: Cleaning. After removing the inner cylinder 634, perform a thorough cleaning in preparation for the next use, ensuring no cross-contamination between samples.

[0128] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A ball mill for determining the TOC of black mudstone and shale source rocks, characterized in that, include: The grinding chamber (1) has a glass plate (2) fixed on one side for observing the operation inside the grinding chamber (1); The opening and closing frame (3) is slidably disposed above the grinding chamber (1) and is raised and lowered by a drive cylinder; The display screen (4) is mounted on the opening and closing frame (3); The lifting assembly (5) is fixed inside the opening and closing frame (3); A sealing component (6) is installed inside the grinding chamber (1) and corresponds to the lifting component (5); Furthermore, the grinding chamber (1) is equipped with at least an air source device and a circulation pump. The air source device is used to provide and store cooling gas, and the circulation pump is used to circulate the cooling gas into the enclosed assembly (6).

2. The ball mill for determining the TOC of black mudstone and shale source rocks according to claim 1, characterized in that, The lifting assembly (5) includes: The lifting cylinder is fixed inside the conveying opening and closing frame (3); A fixed column (51) is fixed to the output end of the lifting cylinder. An air inlet (52) is provided on the side wall of the fixed column (51) and is connected to the air source equipment by the circulating pump. The rotating disk (53) is coaxially rotatably disposed on the lower end face of the fixed column (51); Four rotating columns (57) are configured to rotate circumferentially on the lower end face of the rotating disk (53); The sealing disc (58) is fixed to the lower end face of the rotating column (57).

3. The ball mill for determining the TOC of black mudstone and shale source rocks according to claim 2, characterized in that, An air inlet pipe (54) is fixed through the axial position of the rotating disk (53). The upper end face of the air inlet pipe (54) is connected to the air inlet (52) by a rotary joint. A connecting disk (55) is fixed to the lower end face of the air inlet pipe (54). Multiple connecting pipes (56) are fixed to the circumference of the side wall of the connecting disk (55).

4. A ball mill for determining the TOC of black mudstone and shale source rocks according to claim 3, characterized in that, The lower end face of the sealing disc (58) is fixed with a pressing disc (59), and the lower end face of the pressing disc (59) is fixed with a plurality of pressing pins (591).

5. A ball mill for determining the TOC of black mudstone and shale source rocks according to claim 1, characterized in that, The enclosure component (6) includes: A drive assembly (61) is installed inside the grinding chamber (1), and a drive motor is fixed inside the grinding chamber (1); The outer chamber (62) is fixed to the upper end face of the drive assembly (61) and is sealed to the lifting assembly (5); The base plate (64) is rotatably mounted on the drive assembly (61); The grinding components (63) are configured in four, all of which are rotatably mounted on the base plate (64) and are opened and closed by the lifting components (5).

6. A ball mill for determining the TOC of black mudstone and shale source rocks according to claim 5, characterized in that, The driving component (61) includes: A fixing ring (611) is fixed inside the grinding chamber (1), and an internal toothed ring is fixed on its inner wall; The sun tooth (612) is rotatably mounted at the axial position of the fixed ring (611) and connected to the output end of the drive motor; The planetary teeth (613) are configured in four and mesh with the inner gear ring and the sun tooth (612). The base plate (64) is fitted on the four planetary teeth (613), and the four planetary teeth (613) correspond one-to-one with the four grinding components (63).

7. A ball mill for determining the TOC of black mudstone and shale source rocks according to claim 6, characterized in that, The grinding assembly (63) includes: The mounting plate (631) is fixed at the axial position of the planetary gear (613), and a plurality of positioning pins (632) are fixed on its upper end face. The outer cylinder (633) is fixed to the outer wall of the mounting plate (631); The inner cylinder (634) is detachably mounted on the mounting plate (631) and is positioned by a plurality of the positioning pins (632); A closed ring (635) is fixed to the inner wall of the outer cylinder (633) and is located away from the mounting plate (631). A circulation chamber (636) is located between the outer cylinder (633) and the inner cylinder (634); A circulation component (637) is installed on the outer wall of the outer cylinder (633) and is connected to the lifting component (5); The grading component is installed inside the inner cylinder (634) and away from the mounting plate (631).

8. A ball mill for determining the TOC of black mudstone and shale source rocks according to claim 7, characterized in that, The outer cylinder (633) has multiple through holes (6331) at positions corresponding to the circulation component (637), and the inner cylinder (634) has multiple storage compartments (6341) at positions corresponding to the grading component.

9. A ball mill for determining the TOC of black mudstone and shale source rocks according to claim 8, characterized in that, The loop component (637) includes: An intake ring (6371) is embedded in and rotatably disposed on the outer wall of the outer cylinder (633); The intake valve is fixed on the intake ring (6371) near the center of the base plate (64); The exhaust valve (6372) is fixed at the axial position of the intake ring (6371) away from the base plate (64); An annular cavity (6373) is formed between the intake ring (6371) and the outer cylinder (633).

10. A ball mill for determining the TOC of black mudstone and shale source rocks according to claim 8, characterized in that, The hierarchical component includes: Multiple arc-shaped plates (6381) are configured, all of which are arranged at an angle and are slidably disposed in multiple storage compartments (6341). A spring one or a spring two is disposed between the plate and the storage compartment (6341). The spring one and the spring two are arranged alternately, and the elasticity of the spring two is greater than that of the spring one. A guide surface (6382) is formed on the lower end surface of the arc-shaped plate (6381); Steel balls (6383) are configured in multiple ways, including steel ball one, steel ball two and steel ball three. Steel ball one is directly placed in the inner cylinder (634). Steel ball two and steel ball three are placed alternately in the storage compartment (6341). Steel ball two corresponds to spring one and steel ball three corresponds to spring two. The diameters of the steel balls (6383) are arranged from large to small as steel ball one, steel ball two and steel ball three. A barrier ring (6384) is slidably disposed inside the inner cylinder (634), and initially the storage compartment (6341) is closed by a barrier spring; An inclined surface (6385) is formed on the upper end surface of the barrier ring (6384); The discharge surface (6386) is formed on the inner wall of the barrier ring (6384); The pressing elements (6387) are configured in multiples and are circumferentially fixed to the inner wall of the barrier ring (6384).

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