Graphite ore dry-wet combined grinding system
By combining roller crusher dry grinding and ball mill wet grinding in graphite ore grinding system, combined with spiral grader and multi-stage water selection, the high power consumption of graphite ore and steel is solved in the traditional ball mill powder mill powder mill powder mill powder and graphite ore grinding. The problems of large consumption and fast wear have achieved efficient and low-cost grinding effect.
Patent Information
- Application Number
- CN202420827801.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-19
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-04-19
AI Technical Summary
Traditional ball mill grinding graphite ore has problems such as high power consumption, large steel consumption and fast wear, resulting in increased production costs.
The graphite mine dry and wet grinding system is adopted, combined with the roller crusher dry grinding and the ball mill wet grinding. Through the initial screening of the spiral grader and the multi-stage water selection, the efficient grinding of the materials is achieved.
It reduces power consumption by more than 20% and wear by more than 45%, significantly reduces production costs, and improves grinding efficiency and stability.
Smart Images
Figure CN222469284U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of graphite ore crushing and grinding processing, and in particular relates to a graphite ore dry-wet combined grinding system. Background Art
[0002] In 2023, the national output of graphite concentrate will be about 10 million tons, and the annual amount of graphite ore processed will be about 150 million tons. With the widespread application of graphite in the field of high-tech, its demand is also increasing year by year. For the treatment of graphite ore, the traditional process mainly uses ball mills for crushing and grinding. Water is added to the ball mill, and it is stirred while grinding. After the mud is removed, it enters the spiral classifier for sorting. The material that meets the flotation particle size is taken out of the spiral classifier by water and enters the subsequent flotation system, while the large particle material is sent back to the ball mill by the spiral classifier for grinding again. Because the ball mill uses steel balls for crushing, the material stays in the mill for a long time, the over-grinding is serious, and the power consumption is high. Moreover, because the ball mill is full of water flow during grinding, the grinding steel balls wear quickly. The steel consumption of ball mill grinding graphite ore reaches 1-1.5 kg / t, which greatly increases the processing cost of the enterprise. Utility Model Content
[0003] In view of the problems existing in the prior art, the utility model provides a graphite ore dry-wet combined grinding system.
[0004] The utility model is implemented as follows: a dry-wet combined grinding system for graphite ore comprises a ball mill and a spiral classifier, and also comprises a feeding belt, wherein the feeding belt is connected with an elevator, and the elevator is connected with a roller mill, and the elevator conveys the material transported by the feeding belt into the roller mill; at least one spiral classifier is provided, and the spiral classifier performs preliminary screening on the ground material and returns unqualified material to the ball mill.
[0005] Furthermore, dust collectors are provided outside the elevator and the roller mill to collect dry powder dust.
[0006] Furthermore, the spiral classifier is configured as a primary structure, including a first spiral classifier, the discharge port of the roller mill is connected to the feed port of the first spiral classifier, the discharge port of the first spiral classifier is connected to the feed port of the ball mill, and the discharge port of the ball mill is connected to the feed port of the first spiral classifier.
[0007] Furthermore, the elevator, the roller crusher and the first spiral classifier are arranged in sequence with a height difference; the feed port of the first spiral classifier is lower than the discharge port, and the ball mill is arranged at a height between the feed port and the discharge port of the first spiral classifier; the ground material automatically flows into the next processing equipment by gravity.
[0008] Alternatively, the spiral classifier is configured as a secondary structure, including a second spiral classifier and a third spiral classifier, the discharge port of the roller mill is connected to the feed port of the second spiral classifier, the discharge port of the second spiral classifier is connected to the feed port of the ball mill, the discharge port of the ball mill is connected to the third spiral classifier, and the discharge port of the third spiral classifier is connected to the feed port of the ball mill.
[0009] Furthermore, the elevator, the roller crusher, the second spiral classifier and the ball mill are arranged in sequence with a height difference; the feed port of the third spiral classifier is lower than the discharge port, and the ball mill is arranged at a height between the feed port and the discharge port of the third spiral classifier; the ground material automatically flows into the next processing equipment by gravity.
[0010] Furthermore, the roller mill includes a disc body, a shell is arranged on the disc body, a feed pipe is arranged through the top of the shell, a grinding roller assembly is arranged through the side wall of the shell, the grinding roller assembly is used to grind the material on the disc body, a reducer is arranged on the bottom surface of the disc body, and the reducer is connected to the main motor.
[0011] Furthermore, the disc body is provided with brackets around, and a stirring bin is provided on the inner side of the bracket. The stirring bin surrounds the disc body and a discharge port is provided at the bottom; the cross-section of the stirring bin is U-shaped, and the U-shaped opening is provided upward, so that the ground material falls into the stirring bin from the edge of the disc body; a plurality of scrapers are provided on the bottom surface of the disc body edge, and the scrapers rotate with the disc body, and the scrapers are extended in the stirring bin to stir the material in the stirring bin and push the material out along the discharge port; a movable retaining ring is fixed around the top surface of the disc body, and the movable retaining ring rotates synchronously with the disc body, and the height of the movable retaining ring is set to 40-80mm; a fixed retaining ring is provided on the upper part of the movable retaining ring, and the number of the fixed retaining rings is consistent with that of the roller, and the fixed retaining rings are extended from the feed end of the roller to the discharge end of the roller.
[0012] Furthermore, a water spray pipe is provided through the side wall of the shell, a water outlet of the water spray pipe is provided at the upper part of the mixing bin, and the water spray pipe injects water into the mixing bin.
[0013] Furthermore, the grinding roller assembly includes a loading arm, which is arranged in an L shape, and a roller shaft is arranged at one end of the L shape, and a roller is rollingly connected to the roller shaft; the other end of the L-shaped loading arm is hinged with a loading cylinder;
[0014] A loading arm support is provided on the top surface of the bracket, a hinge hole is provided on the loading arm support, and the turning point of the loading arm is hinged to the loading arm support;
[0015] The fixed end of the loading cylinder is hinged with a cylinder base, and the cylinder base is fixedly connected to the ground foundation.
[0016] The utility model has the following advantages and technical effects:
[0017] 1. This system adopts a grinding system that combines roller crusher material bed dry grinding and ball mill wet grinding, which realizes efficient grinding of graphite ore, reduces power consumption by more than 20%, reduces wear by more than 45%, and greatly reduces production costs.
[0018] 2. This system ensures the stability of mill operation through the design of roller mill buffer discharge pipe and mixing bin, and can discharge muddy materials to be water-selected, which can adapt to the graphite ore water selection process. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural schematic diagram provided by the first embodiment of the utility model;
[0020] Figure 2 It is a structural schematic diagram provided by the second embodiment of the utility model;
[0021] Figure 3 is a top view of a roller mill;
[0022] Figure 4 yes Figure 3 AA section view.
[0023] In the figure: 1. feeding belt; 2. elevator; 3. roller crusher; 4. first spiral classifier; 5. ball mill; 6. dust collector; 7. second spiral classifier; 8. third spiral classifier;
[0024] 31. Main motor; 32. Speed reducer; 33. Disc; 34. Shell; 35. Feeding pipe; 36. Water spray pipe; 37. Roller; 38. Roller shaft; 39. Loading arm; 310. Bracket; 311. Loading cylinder; 312. Cylinder base; 313. Mixing bin; 314. Scraper; 315. Buffer plate; 316. Loading arm support; 317. Discharge port; 318. Grinding roller assembly; 319. Connecting plate; 320. Piston rod; 321. Inspection hole; 322. Inspection door; 323. Moving retaining ring; 324. Fixed retaining ring; 325. Fixed plate. DETAILED DESCRIPTION
[0025] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.
[0026] In the embodiments, unless otherwise specified, the technical means used are conventional technical means in the art.
[0027] A graphite ore dry-wet combined grinding system includes a ball mill 5 and a spiral classifier, and also includes a feeding belt 1, wherein the feeding belt 1 is connected to an elevator 2, and the elevator 2 is connected to a roller mill 3, and the elevator 2 transports the material transported by the feeding belt 1 into the roller mill 3; at least one spiral classifier is provided, and the spiral classifier performs preliminary screening on the ground material and returns unqualified material to the ball mill 5.
[0028] The outer sides of the elevator 2 and the roller mill 3 are sealed and connected with a dust collector 6, and the dust collector 6 collects dry powder dust.
[0029] First embodiment: See Figure 1 The spiral classifier is configured as a primary structure, including a first spiral classifier 4, the discharge port of the roller mill 3 and the feed port of the first spiral classifier 4 are connected via a discharge pipe, the discharge port of the first spiral classifier 4 and the feed port of the ball mill 5 are connected via a discharge pipe, and the discharge port of the ball mill 5 and the feed port of the first spiral classifier 4 are connected via a return pipe.
[0030] The elevator 2, the roller crusher 3, and the first spiral classifier 4 are arranged with a height difference in sequence, that is, the heights of the aforementioned devices are successively reduced, and the height difference is used to allow the material to automatically flow into the next processing device by its own weight; the feed port of the first spiral classifier 4 is lower than the discharge port, and the height of the ball mill 5 is set between the feed port and the discharge port of the first spiral classifier 4; the ground material automatically flows into the next processing equipment by gravity, and no other power facilities are required to drive the movement of the material.
[0031] In this embodiment, the feeding belt 1 conveys the material to the elevator 2, and then feeds the roller mill 3. The material is ground by the roller mill 3, and the content of the finished material with the required particle size after grinding accounts for about 50-70% of the total grinding amount; the ground material is mixed with water in the roller mill 3, and the mixed slurry of the material and water is discharged from the roller mill 3 and flows into the first spiral classifier 4 through the discharge pipe. In the first spiral classifier 4, 50-70% of the finished material with the required particle size flows out of the first spiral classifier 4 with water and enters the subsequent flotation system. After grinding, the large particle material that does not meet the particle size requirements accounts for about 30-50%. The large particle material is brought to the upper part by the first spiral classifier 4 and fed into the ball mill 5 through the discharge pipe. Under the action of the grinding steel balls in the ball mill, it continues to be ground; the ground material is discharged from the ball mill 5, and enters the first spiral classifier 4 again through the return pipe, and is again water-selected and separated in sequence, and finally the material is crushed and ground. The processing capacity of the first spiral classifier 4 is 3 to 5 times the feeding capacity of the graphite ore in the system. This embodiment is more suitable for use in a newly built graphite ore grinding production line.
[0032] In the actual production process, the roller mill 3 produces 50-70% of the finished graphite ore powder, and the roller mill 3 adopts dry layer grinding, which has high grinding efficiency, low power consumption and small wear. Compared with the same ball mill wet grinding, the power consumption is reduced by more than 40%, and the wear is only 0.05Kg / t. According to the calculation that the roller mill produces 50% of the finished graphite ore powder, the power consumption of this grinding system is reduced by more than 20%, and the wear is reduced by more than 45% compared with the traditional ball mill wet grinding system, which greatly reduces the production cost.
[0033] Second embodiment: See Figure 2 The spiral classifier is configured as a secondary structure, including a second spiral classifier 7 and a third spiral classifier 8. The discharge port of the roller mill 3 is connected to the feed port of the second spiral classifier 7 via a discharge pipe, the discharge port of the second spiral classifier 7 is connected to the feed port of the ball mill 5 via a discharge pipe, the discharge port of the ball mill 5 is connected to the feed port of the third spiral classifier 8 via a discharge pipe, and the discharge port of the third spiral classifier 8 is connected to the feed port of the ball mill 5 via a return pipe.
[0034] The elevator 2, the roller crusher 3, the second spiral classifier 7 and the ball mill 5 are arranged with a height difference in sequence, that is, the heights of the aforementioned devices are successively reduced, and the height difference is used to make the materials automatically flow into the next processing equipment by their own weight; the feed port of the third spiral classifier 8 is lower than the discharge port, and the ball mill 5 is arranged at a height between the feed port and the discharge port of the third spiral classifier 8; the ground material automatically flows into the next-level processing device by gravity, and no other power facilities are required to drive the movement of the materials.
[0035] In this embodiment, the feeding belt 1 conveys the material to the elevator 2, and then feeds the material into the roller mill 3. The material is ground by the roller mill 3, and the content of the finished material with the required particle size after grinding accounts for about 50-70% of the total amount of grinding; the ground material is mixed with water in the roller mill 3, and the mixed slurry of the material and water is discharged from the roller mill 3, and flows into the second spiral classifier 7 through the discharge pipe. The finished material with the required particle size overflows from the second spiral classifier 7 with the water and enters the subsequent flotation system.
[0036] After grinding, the large particles that do not meet the particle size requirements account for about 30-50% of the remaining particles. The large particles are brought to the upper part by the second spiral classifier 7 and fed into the ball mill 5 through the discharge pipe. Under the action of the grinding steel balls in the ball mill, the grinding continues. The mixed slurry of the material and water after grinding again is discharged from the ball mill 5, and enters the third spiral classifier 8 through the discharge pipe for water selection again. The finished material with the particle size that meets the requirements in the third spiral classifier 8 overflows with the water flow and enters the subsequent flotation system. The large particles that do not meet the particle size requirements after grinding are brought to the upper part by the third spiral classifier 8, and are fed into the ball mill 5 again through the return pipe to continue grinding until the material is ground and crushed.
[0037] This embodiment is more suitable for partial transformation of the existing ball mill system, because the existing system already has a ball mill and a matching spiral classifier. It only needs to set up a second spiral classifier 7 to process the ground material discharged from the roller mill 3. The processing capacity of the second spiral classifier 7 is 1 to 1.5 times the graphite ore feed amount of the system, which effectively saves investment and reconstruction costs.
[0038] For further information, see Figure 3 , Figure 4 The roller mill 3 includes a disc 33, the disc 33 is fixedly connected to the reducer 32, the main motor 31 and the reducer 32 are connected through a coupling, and the main motor 31 drives the disc 33 to rotate. The speed of the main motor 31 is selected according to the K value, K = n * D (0.5), where n is the disc speed, D is the disc diameter, and the K value is 40-55 when grinding ore.
[0039] The disc 33 is provided with a shell 34, the center of the shell 34 coincides with the center line of the disc 33, and the shell 34 serves to close the grinding area. A feed pipe 35 is provided in the middle of the top of the shell 34 and extends into the shell 34. The feed pipe 35 is welded and fixed to the shell 34.
[0040] The inner wall of the feeding tube 35 is fixedly connected with a buffer plate 315, and the buffer plate 315 is tilted from a fixed point toward the inside of the feeding tube 35, and the tilt angle is set to 40±5 degrees, and its lowest end extends beyond the center line of the feeding tube 35. The number of buffer plates 315 is determined according to the length of the feeding tube 35, and the buffer plates 315 are relatively arranged and distributed downward along the feeding tube 35 in sequence, and the relatively arranged buffer plates 315 are staggered with each other. When the material passes through the buffer plate 315 and falls on the disc 33, the material is slowed down from hitting the disc 33 and splashing.
[0041] The housing 34 is provided with inspection holes 321 corresponding to the grinding roller assembly 318, and the number of the inspection holes 321 is the same as the number of the grinding roller assembly 318; the housing 34 is also provided with an inspection door 322 corresponding to the inspection holes 321; the inspection door 322 is processed with a matching hole, and the matching hole is sealed with the loading arm 9, and the loading arm 39 extends from the outside of the housing 34 through the matching hole into the housing 34. When the grinding mill is running, the inspection door 322 closes the inspection hole 321; when the grinding mill is being repaired, the inspection door 322 can be opened.
[0042] The disc body 33 is surrounded by brackets 310, and a stirring chamber 313 is welded inside the brackets 310. The stirring chamber 313 surrounds the disc body 33, and a discharge port 317 is arranged at the bottom of the stirring chamber 313; the stirring chamber 313 has a U-shaped cross section, and the U-shaped opening is upward, so that the ground material falls into the stirring chamber 313 from the edge of the disc body 33; a plurality of connecting plates 319 are welded on the bottom surface of the edge of the disc body 33, and the connecting plates 319 extend into the stirring chamber 313. The part of the connecting plates 319 located in the stirring chamber 313 is welded with a scraper 314, and the scraper 314 rotates with the disc body 33 to stir the material in the stirring chamber 313 and push the material to be discharged along the discharge port 317. Furthermore, the number of scrapers 314 is determined according to the material stirring requirements and the size of the disc body 33.
[0043] A water spray pipe 36 is provided through the side wall of the shell 34, and the water outlet of the water spray pipe 36 is provided on the upper part of the stirring bin 313. The water spray pipe 36 can inject water into the stirring bin 313. For some ores, such as graphite ore, water sorting is used for subsequent sorting. Before entering the sorting system, the discharged material needs to be stirred with water into a slurry. When water sorting is required for sorting, the water spray pipe 36 is opened to inject water into the stirring bin 313. At the same time, the scraper 314 and the disc 33 rotate synchronously to stir the material and water in the stirring bin 313 into a slurry and then discharge it to meet the subsequent water sorting requirements.
[0044] The top surface of the bracket 310 supports a grinding roller assembly 318, which extends from the outside of the shell 34 into the inside of the shell 34. The grinding roller assembly 318 includes a loading arm 39, which is arranged in an L shape, and one end of the L is fixedly connected to a roller shaft 38, and the roller shaft 38 is rotatably connected to a roller 37, and the roller 37 is suspended on the disc body 33 for grinding the material on the disc body 33; the other end of the L-shaped loading arm 39 is provided with a loading cylinder 311, and the loading cylinder 311 includes a piston rod 320, and the other end of the L-shaped loading arm 39 is hinged to the piston rod 320.
[0045] The top surface of the bracket 310 is provided with a loading arm support 316 , and the loading arm support 316 is provided with a hinge hole. Preferably, the L-shaped turning point of the loading arm 39 is hinged between the two loading arm supports 316 .
[0046] The fixed end of the loading cylinder 311 is hinged with a cylinder base 312, and the cylinder base 312 is fixedly connected to the ground foundation. The loading cylinder 311 realizes the loading arm 39 to drive the roller 37 to rotate along the hinge center line of the loading arm 39 and the loading arm support 316 through the extension and contraction of the piston rod 320. When the disc body 33 rotates, the roller 37 is driven to rotate together, so that the roller 37 grinds the material on the disc body 33; when the piston rod 320 extends upward, the roller 37 approaches the disc body 33, and the distance between the roller 37 and the disc body 33 is adjusted by adjusting the extension amount of the piston rod 320, that is, the grinding pressure of the roller 37 on the material is adjusted to control the particle size of the ground material.
[0047] A movable retaining ring 323 is bolted around the edge of the top surface of the disk body 33. The movable retaining ring 323 rotates synchronously with the disk body 33 and bears the pressure of the roller 37 at the same time. The height of the movable retaining ring 323 is set to 40-80mm. A fixed retaining ring 324 is arranged on the upper part of the movable retaining ring 323. The fixed retaining ring 324 is welded to the inner wall of the shell 34 through a fixed plate 325. The number of the fixed retaining rings 324 is the same as that of the roller 37, and extends from the feed end of the roller 37 to the discharge end of the roller 37 to prevent the material from being discharged without grinding. The area between two adjacent rollers 37 where the fixed retaining ring 324 is not arranged is the discharge area. The material ground by the roller 37 is discharged from the discharge area in time and enters the mixing chamber 313. The new material is blocked by the fixed retaining ring 324 and transported to the bottom of the roller 37 for grinding. The coordinated arrangement of the movable retaining ring 323 and the fixed retaining ring 324 not only reduces over-grinding of materials caused by multiple grinding of materials on the disc body, but also reduces improper discharge of unground materials between the two rollers, thereby reducing ineffective circulation of the system.
[0048] The working principle of the utility model is introduced as follows: Taking the roller crusher with two rollers as an example, the material is buffered and falls to the center of the disc through the discharge pipe. Under the action of the centrifugal force of the rotating disc, the material is spread on the disc to form a material layer. Then the piston rod of the loading cylinder is lifted upward, driving the roller downward to the disc. Driven by the disc, the roller rotates and crushes the material on the disc at the same time. The crushed material is discharged in time from the discharge area between the two rollers where no fixed retaining ring is set. After falling into the mixing bin, it is transported to the discharge port by the scraper for discharge. Alternatively, when water separation is required for sorting, water is added and stirred before discharge. When the grinding is completed and the machine needs to be stopped, the piston rod of the loading cylinder is first retracted to drive the roller upward to leave the disc. Then stop the rotation of the grinding disc and stop the mill.
[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A graphite ore dry-wet combined grinding system, comprising a ball mill (5) and a spiral classifier, characterized in that: The invention also comprises a feeding belt (1), wherein the feeding belt (1) is connected to an elevator (2), wherein the elevator (2) is connected to a roller mill (3), and wherein the elevator (2) transports the material transported by the feeding belt (1) into the roller mill (3); and at least one spiral classifier is provided, wherein the spiral classifier performs preliminary screening on the ground material and returns unqualified material to the ball mill (5).
2. The graphite ore dry-wet combined grinding system according to claim 1 is characterized by: Dust collectors (6) are arranged outside the elevator (2) and the roller mill (3), and the dust collectors (6) collect dry powder dust.
3. The graphite ore dry-wet combined grinding system according to claim 2 is characterized in that: The spiral classifier is configured as a primary structure, comprising a first spiral classifier (4), the discharge port of the roller mill (3) being connected to the feed port of the first spiral classifier (4), the discharge port of the first spiral classifier (4) being connected to the feed port of the ball mill (5), and the discharge port of the ball mill (5) being connected to the feed port of the first spiral classifier (4).
4. The graphite ore dry-wet combined grinding system according to claim 3 is characterized by: The elevator (2), the roller mill (3), and the first spiral classifier (4) are arranged in sequence with a height difference; the feed port of the first spiral classifier (4) is lower than the discharge port, and the ball mill (5) is arranged at a height between the feed port and the discharge port of the first spiral classifier (4); the ground material automatically flows into the next processing equipment by gravity.
5. The graphite ore dry-wet combined grinding system according to claim 2 is characterized by: The spiral classifier is configured as a two-stage structure, comprising a second spiral classifier (7) and a third spiral classifier (8); the discharge port of the roller mill (3) is connected to the feed port of the second spiral classifier (7); the discharge port of the second spiral classifier (7) is connected to the feed port of the ball mill (5); the discharge port of the ball mill (5) is connected to the third spiral classifier (8); and the discharge port of the third spiral classifier (8) is connected to the feed port of the ball mill (5).
6. The graphite ore dry-wet combined grinding system according to claim 5 is characterized by: The elevator (2), the roller mill (3), the second spiral classifier (7) and the ball mill (5) are arranged in sequence with a height difference; the feed port of the third spiral classifier (8) is lower than the discharge port, and the ball mill (5) is arranged at a height between the feed port and the discharge port of the third spiral classifier (8); the ground material automatically flows into the next processing equipment by gravity.
7. The graphite ore dry-wet combined grinding system according to any one of claims 1 to 6, characterized in that: The roller mill (3) comprises a disc body (33), a shell (34) is arranged on the disc body (33), a material discharge pipe (35) is arranged through the top of the shell (34), a grinding roller assembly (318) is arranged through the side wall of the shell (34), and the grinding roller assembly (318) is used to grind the material on the disc body (33). A reducer (32) is arranged on the bottom surface of the disc body (33), and the reducer (32) is connected to a main motor (31).
8. The graphite ore dry-wet combined grinding system according to claim 7 is characterized by: The disc body (33) is provided with brackets (310) around it, and a stirring chamber (313) is provided inside the bracket (310). The stirring chamber (313) surrounds the disc body (33) and is provided with a discharge port (317) at the bottom. The stirring chamber (313) has a U-shaped cross section, and the U-shaped opening is arranged upward, so that the ground material falls from the edge of the disc body (33) into the stirring chamber (313). A plurality of scrapers (314) are arranged on the bottom surface of the edge of the disc body (33). The scrapers (314) rotate with the disc body (33). The scrapers (314) are extended into the stirring chamber (313) to stir the material in the stirring chamber (313) and push the material to be discharged along the discharge port (317). A movable retaining ring (323) is fixed around the top surface of the disk body (33), the movable retaining ring (323) rotates synchronously with the disk body (33), and the height of the movable retaining ring (323) is set to be 40-80 mm; a fixed retaining ring (324) is arranged on the upper part of the movable retaining ring (323), the number of the fixed retaining rings (324) being the same as that of the roller (37), and extending from the feeding end of the roller (37) to the discharging end of the roller (37).
9. The graphite ore dry-wet combined grinding system according to claim 8, characterized in that: A water spray pipe (36) is provided through the side wall of the shell (34); a water outlet of the water spray pipe (36) is provided at the upper part of the mixing chamber (313); and the water spray pipe (36) injects water into the mixing chamber (313).
10. The graphite ore dry-wet combined grinding system according to claim 9, characterized in that: The grinding roller assembly (318) comprises a loading arm (39), the loading arm (39) being arranged in an L shape, a roller shaft (38) being arranged at one end of the L shape, and a roller (37) being rollingly connected to the roller shaft (38); the other end of the L-shaped loading arm (39) being hingedly connected to a loading cylinder (311); A loading arm support (316) is provided on the top surface of the bracket (310), a hinge hole is provided on the loading arm support (316), and a turning point of the loading arm (39) is hinged to the loading arm support (316); The fixed end of the loading oil cylinder (311) is hingedly connected to an oil cylinder base (312), and the oil cylinder base (312) is fixedly connected to a ground foundation.