A drum screen for graphite beneficiation

Abstract

The utility model provides a kind of drum screen for graphite ore dressing belongs to mineral processing equipment technical field, to solve the technical problem that existing drum screen is broken in processing crystalline graphite ore due to material lifting height is too high, impact force is too big and causes large scale graphite sheet.This device includes rack, rotatingly connected with the screen cylinder in the upper portion of rack, the driving mechanism for driving screen cylinder rotation, and: lifting limiting component, by first support fixedly connected in the upper portion of rack, with the limiting baffle of first support fixed connection, limiting baffle is located in the inside of screen cylinder and is located on the lifting path of screening material, for limiting the lifting height of graphite ore in the inside of screen cylinder;Cleaning component is set to the outside of screen cylinder, for cleaning the screen hole blockage of screen cylinder.This device can significantly reduce the falling height and impact energy of material by setting limiting baffle, to reduce the impact damage of large particle ore to graphite scale in screening process, and then improve the economic benefit of graphite ore dressing.

Description

Technical Field

[0001] This utility model relates to the field of graphite beneficiation technology, specifically to a drum screen for graphite beneficiation. Background Technology

[0002] A drum screen is a screening device widely used in mining, building materials, and chemical industries. Its working principle is as follows: material enters the rotating screen cylinder through the feed inlet. Lifting ribs or guide bars on the inner wall of the cylinder continuously carry the material to the upper part of the cylinder. Then, the material tumbles and falls due to gravity. During this process, particles smaller than the screen aperture pass through the screen and become undersize particles, while particles larger than the screen aperture move forward along the inner wall of the cylinder and are eventually discharged from the outlet, thus achieving particle size classification. For most materials, this strong tumbling and falling motion helps to break up agglomerated clumps and improve screening efficiency. However, for crystalline graphite, especially high-value large-flake graphite ore beneficiation, there are significant problems.

[0003] Crystalline graphite has a typical layered hexagonal lattice structure. Carbon atoms within the layers are connected by strong covalent bonds to form stable graphite sheets, while the layers are attracted to each other only by extremely weak van der Waals forces. This structure results in graphite having perfect bottom cleavage properties, meaning that it is very easy to peel and fracture along the interlayer plane under external force. Therefore, graphite has a Mohs hardness of only 1-2 and is extremely brittle.

[0004] In traditional drum screening operations, graphite ore (usually accompanied by gangue minerals with high hardness such as quartz and mica) is lifted to near the highest point of the screen cylinder by the lifting ribs and then falls freely. Its potential energy is converted into huge kinetic energy. When these particles, especially large pieces of hard gangue, impact the material bed at the bottom of the screen cylinder, the impact force generated far exceeds the fracture toughness of graphite along its cleavage plane. This causes the originally intact, high-value large flake graphite (e.g., particle size greater than 300 micrometers) to be repeatedly impacted, broken, and crushed, downgraded into small and medium flakes or graphite powder with lower economic value. This physical damage to the target product directly leads to a significant decrease in the recovery rate of high value-added products, seriously damaging the economic benefits of graphite beneficiation.

[0005] Therefore, there is an urgent need in this field for a new type of drum screening equipment that can achieve effective particle size classification while maximizing the protection of the physical integrity of large flake graphite. Utility Model Content

[0006] The main purpose of this invention is to solve the technical problem that existing drum screens easily lead to excessive material crushing and low recovery rate of high-value products when processing flake graphite, and to provide an improved solution.

[0007] To achieve the above objectives, this utility model provides the following technical solution: A rotary drum screen for graphite beneficiation includes a frame, a screen cylinder rotatably connected above the frame, and a drive mechanism for rotating the screen cylinder. The screen cylinder is characterized by further comprising: The lifting limit assembly consists of a first bracket fixedly connected to the top of the frame and a limiting baffle fixedly connected to the first bracket. The limiting baffle is located inside the screen cylinder and on the lifting path of the screened material when the screen cylinder rotates, and is used to limit the maximum height to which the screened material inside the screen cylinder is lifted. The cleaning component, located on the outside of the screen cylinder, is used to clean the screen holes of the screen cylinder from blockage.

[0008] Furthermore, the first bracket is configured to adjust the height of the limiting baffle in the direction perpendicular to the axis of the screen cylinder.

[0009] Furthermore, the first support is a hydraulic cylinder that is fixedly connected to the top of the frame and located outside the feed inlet and discharge outlet of the screen cylinder.

[0010] Furthermore, a position adjustment mechanism is also connected between the first support and the frame support to adjust the distance between the end of the limiting baffle near the inner wall of the screen cylinder and the inner wall of the screen cylinder.

[0011] Furthermore, the position adjustment mechanism includes a guide rail and a slider. The guide rail is fixedly connected to the top of the frame, and its length is radially distributed along the horizontal direction of the screen cylinder. The slider is fixedly connected to the first bracket and slidably connected to the guide rail. The slider and the guide rail are tightened and fixed together by a tightening bolt.

[0012] Furthermore, the limiting baffle is composed of a first limiting baffle and a second limiting baffle symmetrically distributed along the radial lines of the screen cylinder in the vertical direction of the cross section. The first limiting baffle and the second limiting baffle are distributed at an angle to the radial lines of the screen cylinder in the horizontal direction of the cross section, and the first limiting baffle and the second limiting baffle are spaced apart.

[0013] Furthermore, a flexible scraper is fixedly connected to one end of the limiting baffle near the inner wall of the screen cylinder, and the flexible scraper is in close contact with the inner wall of the screen cylinder.

[0014] Furthermore, the cleaning components are provided in two sets, and the two sets of cleaning components are respectively distributed corresponding to the flexible scraper positions of the first limiting baffle and the second limiting baffle.

[0015] Furthermore, the cleaning assembly consists of a second bracket and a brush. The second bracket is fixedly connected to the top of the frame, and the brush is located on the outside of the screen cylinder. The length of the brush is distributed along the axis of the screen cylinder, and the outer circle of the brush is in contact with the outer wall of the screen cylinder.

[0016] Furthermore, the limiting baffle is composed of a rigid support plate and a buffer layer bonded to the outer surface of the rigid support plate.

[0017] The technical solution provided by this utility model has the following advantages compared with the prior art: 1. By setting a limiting baffle inside the screen cylinder, the lifting height of the screened material can be limited, transforming the "high drop" motion of the traditional drum screen into "low sliding and tumbling", reducing the damage to the crystalline graphite flakes caused by large particles of graphite ore being lifted too high, thereby improving the economic benefits of mineral processing. 2. The height of the limiting baffle inside the screen cylinder is adjusted by the height-adjustable first bracket, so that it can be adaptively adjusted according to different process screening requirements. Furthermore, a position adjustment mechanism is connected between the first bracket and the frame. Through this position adjustment mechanism, the distance between the limiting baffle and the inner wall of the screen cylinder can be adjusted to reduce the probability of large particles of ore in the screening material below escaping to the top of the limiting baffle, thereby further improving the protection effect on large flake graphite. 3. A flexible scraper is provided at one end of the limit baffle near the inner wall of the screen cylinder. The flexible scraper is pressed against the inner wall of the screen cylinder, which can not only further reduce the chance of large ore particles escaping, but also generate rotational friction between the inner wall of the screen cylinder and the flexible scraper during the rotation of the screen cylinder. This friction, in sync with the cleaning components, cleans the inner and outer walls of the screen cylinder, thereby improving the unclogging effect of the screen cylinder. 4. This device can be used simultaneously for screening processes to remove waste rock before graphite ore crushing or for grading operations after graphite ore flotation, improving the protection of large flake graphite in graphite ore during the screening process. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a front view of the structure of the first embodiment of this utility model; Figure 2 This is a top view of the structure of the first embodiment of this utility model; Figure 3 This is a right view of the screen cylinder and the lifting and limiting component in the first embodiment of this utility model in a coordinated state; Figure 4 This is a right view of the screen cylinder and the lifting limiting component in the second embodiment of the present invention. Figure 5 This is a right view of the screen cylinder and the lifting limiting component in the third embodiment of the utility model. in: 1-Frame; 2-Drive motor; 3-Reducer; 4-Belt; 5-Support roller; 6-Drive shaft; 7-Sieve cylinder, 701-First sieve hole, 702-Second sieve hole, 703-Third sieve hole; 8-First support, 801-Hydraulic cylinder, 802-Connecting rod; 9-Limit stop, 901-First limit stop, 902-Second limit stop; 10-Flexible scraper; 11-Guide rail; 12-Slider; 13-Tightening bolt; 14-Second bracket; 15-Brush roller; 16-First storage bin; 17-Second storage bin; 18-Third storage bin. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0021] First Embodiment like Figures 1-3 As shown, this utility model provides a drum screen for graphite beneficiation, including a frame 1, a screen cylinder 7, a drive device for driving the screen cylinder 7 to rotate, a lifting and limiting component, and a cleaning component for cleaning the screen cylinder 7. This device adopts a shaftless drum screen, which can remove waste rock for screening before graphite ore is crushed, or perform grading operation after graphite ore flotation is completed.

[0022] Specifically, in Figure 1 In the view shown, the upper surface of the frame 1 is inclined downwards at a 5-10° angle from left to right. The screen cylinder 7 is located above the frame 1, and its axis is distributed parallel to the upper surface of the frame 1. The left and right ends of the screen cylinder 7 are the feed inlet and the discharge outlet, respectively. The feed inlet and the discharge outlet can be fed by a feed hopper and the discharge outlet can be discharged by a discharge hopper, respectively (not shown in the attached figure). In this embodiment, the classification of graphite ore using a drum screen is used as an example. The screen holes on the screen cylinder 7 are divided into three sections with gradually increasing apertures from left to right along the axial direction of the screen cylinder 7, as shown in the attached figure. Figure 1The first sieve aperture 701, the second sieve aperture 702, and the third sieve aperture 703 shown respectively screen out 80 mesh (approximately 0.18 mm), 50 mesh (approximately 0.30 mm), and 32 mesh (approximately 0.5 mm) crystalline graphite, thereby separating graphite ore into fine flake graphite, medium flake graphite, and large flake graphite. Furthermore, a first storage bin 16, a second storage bin 17, and a third storage bin 18 are fixedly connected to the frame 1. The three bins are located directly below the first sieve aperture 701, the second sieve aperture 702, and the third sieve aperture 703, respectively, and are used to receive the screened fine flake graphite, medium flake graphite, and large flake graphite.

[0023] The drive unit adopts a friction drive method, specifically including a drive motor 2, a reducer 3, a belt 4, a support roller 5, and a drive shaft 6. Both the drive motor 2 and the reducer 3 are fixedly connected to the frame 1. The output shaft of the drive motor 2 and the input shaft of the reducer 3 are connected via the belt 4. Figure 1 In the indicated direction, friction rings that cooperate with the support rollers 5 are provided at both ends of the screen cylinder 7 in the left and right directions, i.e., at both ends of the axial direction. A set of support rollers 5 is provided at the front, back, left, and right of the screen cylinder 7. The support rollers 5 are rotatably connected to the upper end face of the frame 1 through bearings. The two sets of support rollers 5 located in front of the screen cylinder 7 are coaxially fixedly connected through the transmission shaft 6, and the transmission shaft 6 is connected to the output shaft of the reducer 3. The two sets of support rollers 5 located behind the screen cylinder 7 are driven rollers. The support rollers 5 are driven to rotate by the drive motor 2 and the reducer 3, thereby driving the screen cylinder 7 to rotate through the friction between the support rollers 5 and the screen cylinder 7.

[0024] like Figures 1-3 As shown, the lifting and limiting assembly includes a first support 8 and a limiting baffle 9. Two sets of first supports 8 are provided, located outside the feed inlet and discharge outlet of the screen cylinder 7 respectively, and both are fixedly connected to the upper part of the frame 1. The limiting baffle 9 has a rectangular plate structure, fixedly connected between the two sets of first supports 8 and located in the upper part of the screen cylinder 7. Its length is distributed along the axial direction of the screen cylinder 7, and the limiting baffle 9 is located above the material screening upward path. Specifically, as shown... Figure 3 As shown, in this embodiment, the screen cylinder 7 rotates clockwise, and the limiting baffle 9 is located in the second quadrant above the fourth quadrant in the lower left half of the screen cylinder 7. When the material is lifted to a certain height, it will contact the lower surface of the limiting baffle 9 and slide down along it, returning to the material bed below. Its falling height is effectively limited, thereby avoiding the generation of high impact force. Thus, the lifting height of the graphite ore is limited by the limiting baffle 9 during the graphite ore screening process.

[0025] In this embodiment, the limiting baffle 9 is inclined, specifically, as shown below. Figure 3As shown, the end of the limiting baffle 9 closest to the inner wall of the screen cylinder 7 (left end) is the high point, and the right end is the low point. The purpose of this setting is that if a small amount of large ore particles bypass the limiting baffle 9 during the screening process, the large ore particles can slide down along the inclined limiting baffle 9 to the top of the screened material after entering the position above the limiting baffle 9, so as to further reduce the impact on the screened material at the bottom of the screen cylinder 7.

[0026] To further reduce impact, the limiting baffle 9 adopts a composite structure of a rigid support plate and a buffer layer. The rigid support plate is a high manganese steel plate, and the buffer layer is polyurethane bonded to the outer surface of the rigid support plate. Its hardness is Shore A60-A70, which can reduce the hard impact of graphite ore during the tumbling process.

[0027] In this embodiment, the first support 8 is a height-adjustable hydraulic cylinder 801. The cylinder body of the hydraulic cylinder 801 is fixedly connected to the upper end face of the frame 1. The piston rod axis is distributed perpendicular to the upper end face of the frame 1, and the upper end of the piston rod is fixedly connected to the limiting baffle 9 through the connecting rod 802. By setting a proportional control valve on the hydraulic cylinder oil supply passage to adjust the flow rate, the extension length of the piston rod of the hydraulic cylinder 801 can be controlled, thereby controlling the height of the limiting baffle 9 inside the screen cylinder 7.

[0028] To adapt to different working conditions, a limit baffle 9 is also provided between the hydraulic cylinder 801 and the frame 1 for adjusting the distance between the limit baffle 9 and the inner wall of the screen cylinder 7 in the front-back direction. Figure 1 The position adjustment mechanism on the reference view consists of a guide rail 11 and a slider 12. The guide rail 11 is distributed along the front-back direction and is fixedly connected to the top of the frame 1. The slider 12 is fixedly connected to the bottom of the cylinder of the hydraulic cylinder 801 and slides with the guide rail 11. The slider 12 is also provided with through threaded holes distributed perpendicular to the upper end face of the frame 1. A tightening bolt 13 is threaded into the threaded hole. After the tightening bolt 13 passes through the threaded hole, it can be tightened against the upper end face of the guide rail 11, thereby fixing the slider 12 and the guide rail 11. This device can adaptively adjust the distance between the end of the limiting baffle 9 near the inner wall of the screen cylinder 7 and the inner wall of the screen cylinder 7 through the guide rail 11 and the slider 12, thereby minimizing the probability of impurities entering the upper part of the limiting baffle 9 during the screening process. It should be noted that in this embodiment, the limiting baffle 9 does not contact the inner wall of the screen cylinder 7.

[0029] Operators can precisely adjust the height of the limiting baffle 9 according to different working conditions such as ore type, particle size distribution, and moisture content, and adjust the gap between the limiting baffle 9 and the inner wall of the screen cylinder 7 through the position adjustment mechanism to find the best balance point between protection and screening for specific materials.

[0030] Clean up components such as Figure 1 and Figure 2As shown, it consists of a second support 14 and a brush roller 15. Two sets of second supports 14 are fixedly connected to the top of the frame 1 and are respectively located on one side of the feed inlet and the discharge outlet of the screen cylinder 7. The length of the brush roller 15 is distributed along the axial direction of the screen cylinder 7, and the two ends of its metal shaft are rotatably connected to the second support 14 through bearings fixed on the two sets of second supports 14. In this embodiment, two sets of brush rollers 15 are provided, respectively located on the upper part of the front and rear sides of the screen cylinder 7. The screen cylinder 7 can be cleared of blockages by the brush rollers 15.

[0031] The purpose of this device is to prevent large ore particles (such as mica ore) from being lifted too high during screening. This can cause significant impact on the graphite flakes, resulting in damage. Therefore, this device uses a lifting limit component to block large ore particles and reduce their damage to the graphite flakes. Furthermore, the buffer rubber on the surface of the limit baffle 9 further reduces the impact on the large graphite flakes, thus minimizing damage.

[0032] It should be noted that setting the limiting baffle 9 may reduce the screening efficiency of graphite ore to some extent. However, the purpose of this scheme is to improve the protection of large flake graphite during the beneficiation process. Moreover, in actual application, the screening efficiency decreases by only 5% to 10% compared with the absence of the limiting baffle 9. Compared with the purpose of this scheme, this drawback can be disregarded.

[0033] Second Embodiment This embodiment adds a set of lifting limit components based on the first embodiment, such as Figure 4 As shown, the limiting baffle 9 includes a first limiting baffle 901 and a second limiting baffle 902, which are respectively connected to the position adjustment mechanism through a set of first brackets 8. The first limiting baffle 901 and the second limiting baffle 902 are in Figure 4 The two sides are symmetrically distributed in the view shown. If the trajectory of large ore particles that escape from the gap between the inner wall of the screen cylinder 7 and the first limiting baffle 901 during the screening process exceeds the right side of the first limiting baffle 9, the capture probability can be increased by setting the second limiting baffle 902.

[0034] Furthermore, a certain gap is provided between the first limiting baffle 901 and the second limiting baffle 902 so that large particles of ore that escape to the top of the first limiting baffle 901 and the second limiting baffle 902 fall back to the bottom screening layer of the screen cylinder 7, thus avoiding the accumulation of materials on the limiting baffle 9.

[0035] Third Embodiment This embodiment adds a flexible scraper 10 to the second embodiment to further improve the sealing effect of the limiting baffle 9, and at the same time, it works with the brush roller 15 to improve the unblocking effect of the drum screen.

[0036] like Figure 5 As shown, flexible scrapers 10 are fixedly connected to one end of the first limiting baffle 901 and the second limiting baffle 902 near the inner wall of the screen cylinder 7. The flexible scrapers 10 are made of polyethylene material. In the installed state, after the height is adjusted by the hydraulic cylinder 801, the flexible scrapers 10 can be adjusted in the left and right directions by moving the guide rail 11 and the slider 12. Figure 5 Positioned in the direction shown in the view, so that one end of the flexible scraper 10 is tightly attached to the inner wall of the screen cylinder 7.

[0037] By having the flexible scraper 10 closely adhere to the inner wall of the screen cylinder 7, the probability of large ore particles in the screened material escaping to the limit baffle 9 can be further reduced, thereby improving the protection effect on large flake graphite. Moreover, in this embodiment, the height of the two sets of flexible scrapers 10 is consistent with the height of the two sets of brush rollers 15, and the contact position of the flexible scraper 10 corresponds to the position of the brush roller 15. When the screen cylinder 7 rotates, the flexible scraper 10 continuously rubs and collides with the screen holes on the inner wall of the screen cylinder 7, which can cooperate with the brush roller 15 to clean the inner and outer surfaces of the screen respectively, thereby improving the screen unclogging effect.

[0038] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this utility model.

Claims

1. A rotary drum screen for graphite beneficiation, comprising a frame, a screen cylinder rotatably connected above the frame, and a drive mechanism for rotating the screen cylinder, characterized in that: It also includes: The lifting limit assembly consists of a first bracket fixedly connected to the top of the frame and a limiting baffle fixedly connected to the first bracket. The limiting baffle is located inside the screen cylinder and on the lifting path of the screened material when the screen cylinder rotates, and is used to limit the maximum height to which the screened material inside the screen cylinder is lifted. And a cleaning component located on the outside of the screen cylinder for cleaning the screen holes of the screen cylinder.

2. The rotary drum screen for graphite beneficiation according to claim 1, characterized in that, The first bracket is configured to adjust the height of the limiting baffle in the direction perpendicular to the axis of the screen cylinder.

3. The rotary drum screen for graphite beneficiation according to claim 2, characterized in that, The first support is a hydraulic cylinder that is fixedly connected to the top of the frame and located outside the feed inlet and discharge outlet of the screen cylinder.

4. The rotary drum screen for graphite beneficiation according to claim 1 or 3, characterized in that, A position adjustment mechanism is also connected between the first bracket and the frame bracket to adjust the distance between the end of the limiting baffle near the inner wall of the screen cylinder and the inner wall of the screen cylinder.

5. The rotary drum screen for graphite beneficiation according to claim 4, characterized in that, The position adjustment mechanism includes a guide rail and a slider. The guide rail is fixedly connected to the top of the frame and its length is radially distributed along the horizontal direction of the screen cylinder. The slider is fixedly connected to the first bracket and slidably connected to the guide rail. The slider and the guide rail are tightened and fixed together by a tightening bolt.

6. The rotary drum screen for graphite beneficiation according to claim 1, characterized in that, The limiting baffle consists of a first limiting baffle and a second limiting baffle symmetrically distributed along the radial lines of the screen cylinder in the vertical direction of the cross-section. The first limiting baffle and the second limiting baffle are distributed at an angle to the radial lines of the screen cylinder in the horizontal direction of the cross-section, and the first limiting baffle and the second limiting baffle are spaced apart.

7. The rotary drum screen for graphite beneficiation according to claim 1 or 6, characterized in that, A flexible scraper is fixedly connected to one end of the limiting baffle near the inner wall of the screen cylinder, and the flexible scraper is in close contact with the inner wall of the screen cylinder.

8. The rotary drum screen for graphite beneficiation according to claim 7, characterized in that, The cleaning components are provided in two sets, and the two sets of cleaning components are respectively distributed corresponding to the flexible scraper positions of the first limiting baffle and the second limiting baffle.

9. The rotary drum screen for graphite beneficiation according to claim 1 or 8, characterized in that, The cleaning assembly consists of a second bracket and a brush. The second bracket is fixedly connected to the top of the frame, and the brush is located on the outside of the screen cylinder. The length of the brush is distributed along the axis of the screen cylinder, and the outer circle of the brush is in contact with the outer wall of the screen cylinder.

10. The rotary drum screen for graphite beneficiation according to claim 1, characterized in that, The limiting baffle consists of a rigid support plate and a buffer layer bonded to the outer surface of the rigid support plate.

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