Combined screening device for improving recovery rate of fine particle bauxite

Abstract

The utility model provides a kind of combined screening device of improving fine particle grade bauxite recovery rate, it is related to bauxite processing equipment technical field.A kind of combined screening device of improving fine particle grade bauxite recovery rate includes screening mechanism one, screening mechanism two and the conveying mechanism of intercommunication screening mechanism one and screening mechanism two;The screening mechanism one includes sieve box, screen cloth being installed in the sieve box interior and be used for driving the drive arrangement one of sieve box movement;The screening mechanism two includes fixed sieve frame, floating sieve frame being installed in the fixed sieve frame and be used for driving the drive arrangement two of fixed sieve frame movement, and the floating sieve frame is equipped with elastic sieve plate.This device can solve the problem of sticky wet material blockage screen hole, can significantly improve the recovery efficiency of fine particle grade ore (5-10mm).

Description

Technical Field

[0001] This utility model relates to the technical field of bauxite processing equipment, and more specifically, to a combined screening device for improving the recovery rate of fine-grained bauxite. Background Technology

[0002] The ore samples were collected using shallow well drilling and then sieved before being sent to the laboratory for drying and analysis. Analysis of the particle size distribution and chemical data revealed an uneven distribution of particle sizes. The 5-10mm, 10-20mm, 20-30mm, 30-50mm, and 50-70mm sizes were the most concentrated, accounting for 13.31%, 14.23%, 17.84%, 16.13%, and 13.77% respectively, totaling 75.28%. The silicon content gradually decreased from small to large particle sizes, with the aluminum-silicon ratio ranging from 2.00 to 6.15.

[0003] Currently, the screening equipment mainly uses a combination of two circular vibrating screens (drum screens) for bauxite screening and recovery. However, this method has the following shortcomings: First, it is greatly affected by the moisture content and looseness of the raw ore. Relevant test data shows that when the moisture content of the raw ore is ≤15%, the screening runs smoothly and basically does not require stopping the machine to clean the screen. When the moisture content of the raw ore is in the range of 15-20%, after 2 hours of screening, most of the screen holes of the fine screen become clogged, requiring a 20-minute shutdown for screen cleaning to ensure the screening effect. When the moisture content of the raw ore is >20%, after 30 minutes of screening, the screen holes of the fine screen become basically clogged, leading to frequent shutdowns for cleaning, each cleaning session lasting 40 minutes. Second, the ore screening recovery rate is low, only 39.91%, resulting in significant ore screening losses. Third, it can only recover ore with a particle size of 10mm or larger, which results in the waste of ore with a particle size of 5-10mm. Based on the net ore reserves of 2.9191 million tons of Waishantou bauxite, the loss of ore with a particle size of 5-10mm alone reaches 388,500 tons. Utility Model Content

[0004] The purpose of this invention is to provide a combined screening device that improves the recovery rate of fine-grained bauxite, which can solve the problem of screen holes being blocked by sticky and wet materials and can significantly improve the recovery efficiency of fine-grained ore (5-10mm).

[0005] This utility model is achieved through the following technical solution: A combined screening device for improving the recovery rate of fine-grained bauxite includes a screening mechanism one, a screening mechanism two, and a conveying mechanism connecting the screening mechanism one and the screening mechanism two; the screening mechanism one includes a screen box, a screen installed inside the screen box, and a drive device one for driving the screen box to move; the screening mechanism two includes a fixed screen frame, a floating screen frame installed inside the fixed screen frame, and a drive device two for driving the fixed screen frame to move, wherein the floating screen frame is provided with an elastic screen plate.

[0006] Furthermore, the screen box is installed on the top of the support base frame, and the drive device includes a vibrator, which is movably connected to the screen box via a bearing. The input end of the vibrator is connected to the output end of the servo motor via a transmission mechanism.

[0007] Furthermore, a hopper is provided at the outlet of the screen box, and a discharge pipe is provided at the bottom of the hopper. The discharge pipe is located at the material inlet of the conveying mechanism.

[0008] Furthermore, the screen box is equipped with two layers of screen mesh, which are small round steel woven screen meshes, and the apertures of the two layers of screen mesh are 20mm and 50mm respectively.

[0009] Furthermore, the fixed screen frame is installed on the top of the support leg, and the second driving device includes a second vibrator, which is installed inside the fixed screen frame. The input end of the second vibrator is connected to the output end of the second servo motor through a transmission mechanism.

[0010] Furthermore, the outer wall of the screen box is provided with support springs.

[0011] Furthermore, the elastic sieve plate is provided with sieve holes of gradually varying diameters, the diameter of which is 5-7mm.

[0012] Furthermore, the conveying mechanism includes a roller frame, a support frame, rollers, a conveyor belt, and a drive mechanism. The roller frame is rotatably connected to the support frame, the rollers are rotatably mounted at both ends of the roller frame, the conveyor belt is wrapped around the outside of the two rollers, and the drive mechanism is used to drive the rollers to rotate.

[0013] The technical solution of this utility model has at least the following advantages and beneficial effects: 1. First, the coarse-grained ore is preliminarily screened by screening mechanism one. Then, the elastic screen plate and high-frequency vibration characteristics of screening mechanism two solve the problem of sticky and wet materials clogging the screen holes, thereby significantly improving the recovery efficiency of fine-grained ore (5-10mm).

[0014] 2. In the second screening mechanism, the linear vibration of the fixed screen frame is combined with the additional vibration of the floating screen frame, and the tension and relaxation motion of the elastic screen plate is used to throw the material, so that the material acceleration reaches 50G. This not only effectively prevents sticky and wet materials from sticking to the screen plate, but also prevents fine particles from clogging the screen holes, significantly improving screening efficiency and achieving high-efficiency screening.

[0015] 3. The conveying mechanism can adjust the feeding speed of the second screening mechanism to avoid material accumulation, ensure stable screening efficiency, and improve screening quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the combined screening device for improving the recovery rate of fine-grained bauxite provided in Embodiment 1 of this utility model. Figure 2 This is a schematic diagram of the structure of a screening mechanism provided in Embodiment 1 of this utility model; Figure 3 This is a schematic diagram of the structure of the screening mechanism 2 provided in Embodiment 1 of this utility model; Figure 4 This is a schematic diagram of the conveying mechanism provided in Embodiment 1 of this utility model.

[0018] Icons: 100-Screening mechanism one, 101-Screen box, 102-Screen mesh, 103-Vibrator one, 104-Servo motor one, 105-Support base frame, 106-Hopper, 107-Discharge pipe, 108-Support spring; 200-Screening mechanism two, 201-Fixed screen frame, 202-Floating screen frame, 203-Elastic screen plate, 204-Vibrator two, 205-Support leg; 300-Conveying mechanism, 301-Roller frame, 302-Support frame, 303-Roller, 304-Conveyor belt, 305-Drive mechanism. Detailed Implementation

[0019] 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 embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] Example 1 Reference Figures 1-4This embodiment provides a combined screening device for improving the recovery rate of fine-grained bauxite, including a screening mechanism 100, a screening mechanism 200, and a conveying mechanism 300 connecting the screening mechanism 100 and the screening mechanism 200; the screening mechanism 100 includes a screen box 101, a screen 102 installed inside the screen box 101, and a driving device 1 for driving the screen box 101 to move; the screening mechanism 200 includes a fixed screen frame 201, a floating screen frame 202 installed inside the fixed screen frame 201, and a driving device 2 for driving the fixed screen frame 201 to move, wherein the floating screen frame 202 is provided with an elastic screen plate 203.

[0024] First, coarse-grained ore is preliminarily screened using screening mechanism 100. Then, the elastic screen plate 203 and high-frequency vibration characteristics of screening mechanism 200 solve the problem of sticky and wet materials clogging the screen holes, thereby significantly improving the recovery efficiency of fine-grained ore (5-10mm). In screening mechanism 200, the linear vibration of the fixed screen frame 201 combined with the additional vibration of the floating screen frame 202, along with the tension and relaxation motion of the elastic screen plate 203, throws the material, allowing the material acceleration to reach 50G. This not only effectively prevents sticky and wet materials from adhering to the screen plate but also prevents fine-grained materials from clogging the screen holes, significantly improving screening efficiency and achieving high-efficiency screening. The conveying mechanism 300 can adjust the feeding speed of screening mechanism 200 to avoid material accumulation, ensure stable screening efficiency, and improve screening quality.

[0025] In this embodiment, the screen box 101 is mounted on top of the support frame 105. The driving device includes a vibrator 103, which is movably connected to the screen box 101 via bearings. The input end of the vibrator 103 is connected to the output end of the servo motor 104 via a transmission mechanism. The vibrator 103, driven by the servo motor 104, generates an excitation force, causing the screen box 101 to reciprocate, thereby achieving material screening. Specifically, the servo motor 104 drives the eccentric block to rotate, generating centrifugal force, which is converted into vibration energy of the screen box 101.

[0026] In this embodiment, the sieve box 101 is provided with a hopper 106 at its outlet, and the bottom of the hopper 106 is provided with a discharge pipe 107, which is located at the material inlet of the conveying mechanism 300.

[0027] In this embodiment, the sieve box 101 is provided with two layers of sieve mesh 102, which are small round steel woven sieve mesh 102, and the apertures of the two layers of sieve mesh 102 are 20mm and 50mm respectively. The two layers of sieve mesh 102 can improve the screening quality.

[0028] In this embodiment, the fixed screen frame 201 is mounted on the top of the support leg 205, and the second driving device includes a second vibrator 204. The second vibrator 204 is installed inside the fixed screen frame 201, and the input end of the second vibrator 204 is connected to the output end of the second servo motor through a transmission mechanism.

[0029] In operation, the screening mechanism 200 generates two types of vibrations through a single drive: linear vibration of the fixed screen frame 201 and additional vibration of the floating screen frame 202. These two vibrations interact, causing the elastic screen plate 203 to produce a high-frequency relaxation motion. That is, the elastic screen plate 203 undergoes elastic deformation under continuous flexural motion, thereby throwing wet, sticky materials off the screen surface. Under the relative motion of the fixed screen frame 201 and the floating screen frame 202, the elastic screen plate 203 continuously expands and contracts, forming a high-frequency relaxation motion. This motion transmits an acceleration of up to 50g to the material, fully loosening and allowing it to pass through the screen, thus improving screening efficiency. When material enters the elastic screen plate 203, the high-frequency relaxation motion of the elastic screen plate 203 subjectes the material to alternating tension and relaxation, generating a forward bouncing motion. This motion helps the material to stratify and pass through the screen, while preventing material from clogging the screen holes.

[0030] In this embodiment, a support spring 108 is provided on the outer wall of the screen box 101. The support spring 108 has a buffering function, and a support spring 108 can also be provided on the outer wall of the fixed screen frame 201.

[0031] In this embodiment, the elastic sieve plate 203 has sieve holes with a gradually changing aperture of 5-7 mm. The sieve holes of the elastic sieve plate 203 are distributed in a rectangular array, and can be divided into three sections along the material movement direction: the first section has 5 mm sieve holes, the second section has 6 mm sieve holes, and the third section has 7 mm sieve holes, forming a gradually changing aperture structure that can adapt to the dynamic screening requirements of materials of different particle sizes. In other embodiments, it can also be divided into three, five, or other numbers of sections, which can be selected according to actual needs.

[0032] In this embodiment, the conveying mechanism 300 includes a roller frame 301, a support frame 302, rollers 303, a conveyor belt 304, and a drive mechanism 305. The roller frame 301 is rotatably connected to the support frame 302. The rollers 303 are rotatably mounted at both ends of the roller frame 301. The conveyor belt 304 is wound around the outside of the two rollers 303. The drive mechanism 305 drives the rollers 303 to rotate. The drive mechanism 305 includes a frequency converter, a reducer, and a motor. The frequency converter is electrically connected to the motor, the output end of the motor is connected to the reducer, and the reducer is connected to one of the rollers. Frequency conversion speed regulation can adjust the rotational speed of the conveying mechanism 300 (52%-60% range), optimizing the feeding speed of the screening mechanism 200, avoiding material accumulation, and ensuring stable screening efficiency.

[0033] During operation, the mined bauxite ore is fed to screening mechanism 100. Servo motor 104 drives vibrator 103 to generate excitation force, which causes screen box 101 and screen 102 to vibrate and achieve screening. The oversize material with a particle size greater than 20mm after screening by screening mechanism 100 is stored as coarse ore in a temporary stockpile awaiting transportation to the next process in the alumina plant. The ore with a particle size less than 20mm is conveyed to the next screening mechanism 200 through conveyor mechanism 300 with speed controlled by frequency converter. Servo motor 2 drives vibrator 204 to generate excitation force, which causes fixed screen frame 201 and floating screen frame 202 to vibrate, which in turn causes elastic screen plate 203 to vibrate and achieve screening. The oversize material with a particle size of 5-20mm after screening by screening mechanism 200 is transported to the alumina plant by truck as middlings and coarse ore in a certain proportion. The undersize material with a particle size less than 5mm is directly transported to the mined-out area for backfilling and reclamation as tailings.

[0034] During the screening process, the speed of the conveyor mechanism 300 is adjusted according to the mud content of the material on the screen of screening mechanism 200 to control the feeding speed of screening mechanism 200. After long-term operation, it was found that when the tensile vibration frequency of screening mechanism 200 is adjusted to 42Hz, the material is repeatedly thrown up, loosened, stratified, and screened under the action of lateral tensile and longitudinal vibration. However, when the speed of conveyor mechanism 300 is 100%, there is obvious material accumulation on the screen surface that cannot be screened; when the speed of conveyor mechanism 300 is adjusted to 52-60%, the material accumulation is significantly improved, and the screening effect is more ideal. After long-term production operation data statistical analysis, the screening recovery rate has increased from 39.91% in the traditional screening process to 81.69%.

[0035] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A combined screening device for improving the recovery rate of fine-grained bauxite, characterized in that: The system includes a screening mechanism one, a screening mechanism two, and a conveying mechanism connecting the screening mechanism one and the screening mechanism two; the screening mechanism one includes a screen box, a screen installed inside the screen box, and a drive device one for driving the screen box to move; the screening mechanism two includes a fixed screen frame, a floating screen frame installed inside the fixed screen frame, and a drive device two for driving the fixed screen frame to move, wherein the floating screen frame is provided with an elastic screen plate.

2. The combined screening device for improving the recovery rate of fine-grained bauxite according to claim 1, characterized in that, The screen box is installed on the top of the support frame. The drive device includes a vibrator, which is movably connected to the screen box via a bearing. The input end of the vibrator is connected to the output end of the servo motor via a transmission mechanism.

3. The combined screening device for improving the recovery rate of fine-grained bauxite according to claim 1, characterized in that, The screen box is equipped with a hopper at its outlet, and a discharge pipe is provided at the bottom of the hopper. The discharge pipe is located at the material inlet of the conveying mechanism.

4. The combined screening device for improving the recovery rate of fine-grained bauxite according to claim 1, characterized in that, The screen box is equipped with two layers of screen mesh, which are small round steel woven screen meshes, with apertures of 20mm and 50mm respectively.

5. The combined screening device for improving the recovery rate of fine-grained bauxite according to claim 1, characterized in that, The fixed screen frame is installed on the top of the support leg. The second driving device includes a second vibrator, which is installed inside the fixed screen frame. The input end of the second vibrator is connected to the output end of the second servo motor through a transmission mechanism.

6. The combined screening device for improving the recovery rate of fine-grained bauxite according to claim 1, characterized in that, The outer wall of the sieve box is equipped with support springs.

7. The combined screening device for improving the recovery rate of fine-grained bauxite according to claim 1, characterized in that, The elastic sieve plate has sieve holes with gradually varying apertures, the aperture being 5-7 mm.

8. The combined screening device for improving the recovery rate of fine-grained bauxite according to claim 1, characterized in that, The conveying mechanism includes a roller frame, a support frame, rollers, a conveyor belt, and a drive mechanism. The roller frame is rotatably connected to the support frame. The rollers are rotatably mounted at both ends of the roller frame. The conveyor belt is wrapped around the outside of the two rollers. The drive mechanism is used to drive the rollers to rotate.

Images