Asparagus screening device and asbestos tailing grading recovery system

Abstract

The utility model discloses an asbestos screening device and an asbestos tailing grading recovery system, the asbestos screening device comprises a dust collector and a screening device with an inner cavity, and the top of the screening device is communicated with the dust collector through a pipeline; a material inlet is formed in the side wall of the screening device, and materials to be treated enter an inner cavity of the screening device through the material inlet in a pneumatic conveying manner; a screen is arranged on the inner side wall of the screening device in the direction of the cross section, and the screen is arranged above the feeding port. The surface area of the screen is larger than the cross section area of the sifter, and a gravity hammer is arranged on the screen. The asbestos screening device solves the technical problem that the recovery efficiency of chrysotile products is low due to the fact that chrysotile mixed materials containing dust are sorted only through wind power.

Description

Technical Field

[0001] The utility model belongs to the technical field of comprehensive utilization of tailings, and particularly relates to an asbestos screening device and an asbestos tailings classification recovery system. Background Art

[0002] Asbestos tailings are the tailings discharged from chrysotile asbestos mining and beneficiation operations. Their mineral composition is primarily serpentine, with small amounts of brucite and magnetite. The storage of asbestos tailings not only occupies land and pollutes the environment, but also leads to a waste of resources. Asbestos tailings can be used to extract MgO and SiO2, but some of the fibers in the tailings significantly impact the leaching and filtration processes, resulting in low leaching rates, high filter cake moisture content, and low leachate recovery efficiency. Therefore, it is necessary to remove this portion of the asbestos from the tailings to improve the efficiency of the leaching and filtration operations.

[0003] Chinese invention patent application publication number CN103433137A proposes a comprehensive recovery method for chrysotile tailings that integrates crushing and sorting. The key technical points are: the dried chrysotile tailings are fed into an integrated crushing and sorting device consisting of a grinder and a cyclone powder collector; 4 to 8 sand discharge outlets are added to the grinding disc of the grinder to achieve grinding and sorting, and the chrysotile tailings are sorted into a dust-containing chrysotile mixture and tailings waste; the chrysotile mixture is conveyed to a flat gyratory screen or a flat shaking screen for classification and dust removal, and fine sand and dust are removed to obtain chrysotile products of different grades; the tailings waste and fine sand dust are roughly separated by a weak magnetic separator to obtain magnetic middlings and tailings; the magnetic middlings are sent to a ball mill for grinding, and then sent to a wet weak magnetic separator for separation to obtain magnetite concentrate and tailings. The integrated recovery method incorporates a grinding mill with four to eight circular openings for sand discharge on its grinding disc. These discharge tailings, while fine dust and lighter chrysotile asbestos are lifted by wind and enter a cyclone dust collector. The tailings are then removed and discharged through a dust collector. Using wind alone to separate the dust-laden chrysotile mixture, some chrysotile products could be carried into the cyclone, impacting the recovery efficiency of the chrysotile products. Utility Model Content

[0004] In response to the current technical problems, the utility model aims to provide an asbestos screening device and an asbestos tailings classification and recovery system. The asbestos screening device can solve the technical problem of low chrysotile product recovery efficiency caused by sorting dusty chrysotile asbestos mixed materials only by wind power.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] An asbestos screening device has the following structural features: it includes a dust collector and a screener with an inner cavity, the top of the screener is connected to the dust collector through a pipeline; a feed port is provided on the side wall of the screener, and the material to be processed enters the inner cavity of the screener through the feed port by pneumatic conveying; a screen is provided on the inner side wall of the screener along the cross-sectional direction, and the screen is arranged above the feed port; the surface area of the screen is larger than the cross-sectional area of the screener, and a gravity hammer is provided on the screen.

[0007] The dusty chrysotile mixture to be processed is pneumatically conveyed through the feed port into the inner cavity of the screener. The screen is lifted upward by the airflow, allowing the fine particles in the mixture to pass through the screen and enter the dust collector, while the coarse particles adhere to the screen. When the screen is filled with coarse particles, the material is conveyed and the screen is tilted downward by the gravity of the gravity hammer. The coarse particles on the screen are discharged into the bottom of the screener, thus separating the fine and coarse particles in the mixture.

[0008] Preferably, the mesh size of the sieve is 45-60 μm. The mesh size can be square or round. A mesh size of 45-60 μm can separate coarse particles of 50-74 μm, thereby recovering 50-74 μm fiber asbestos to form asbestos products.

[0009] Preferably, the screen is a conical structure, the large diameter end of the conical structure is connected to the inner wall of the screener, the gravity hammer is arranged on the small diameter end of the conical structure, and the feed port is arranged below the large diameter end of the conical structure.

[0010] Preferably, an air turbidity sensor is provided on the inner sidewall of the sifter or the inner sidewall of the duct connecting the sifter and the dust collector, and the air turbidity sensor is provided above the sieve. When the turbidity detected by the air turbidity sensor is lower than a set value, it indicates that the sieve is full of large particles, and the material is stopped from being transported into the sifter.

[0011] Specifically, the bottom of the dust collector is connected to the induced draft fan through a pipeline, and the air outlet of the induced draft fan is connected to the chimney.

[0012] Preferably, the dust collector is a bag dust collector.

[0013] Based on the same inventive concept, the present application also provides an asbestos tailings grading and recovery system, comprising a raw material bin, a column mill, a delivery pump, an asbestos recovery device, and the asbestos screening device described above, wherein the column mill is equipped with a blower; the discharge port of the raw material bin is connected to the feed port of the column mill, and the discharge port of the column mill is connected to the feed port of the screener; the bottom of the screener is connected to the inlet of the delivery pump, and a valve is provided at the connection point, and the delivery pump is used to transport the material in the screener to the asbestos recovery device for graded recovery. The asbestos recovery device can use a flat rotary screen or a flat shaking screen in the prior art, such as the invention patent CN103433137A, which uses a flat rotary screen or a flat shaking screen for grading and dust removal, removes fine sand and dust, and obtains different grades of chrysotile asbestos products. The asbestos tailings in the raw material bin enter the column mill for grinding, and the particle size of the finished material after grinding and crushing is about 74μm. Close the valve at the bottom of the screener and start the blower in the column mill. The finished material is pneumatically conveyed into the screener by the blower. The airflow causes the screen to rise upward, allowing fine particles to pass through and enter the dust collector, while coarse particles adhere to the screen. When the screen is filled with coarse particles, turn off the blower and open the valve at the bottom of the screener. The screen is tilted downward by the force of the gravity hammer, and the coarse particles on the screen are discharged into the bottom of the screener and into the transfer pump. After the valve at the bottom of the screener is closed, start the blower in the column mill to supply air, causing the screen to rise upward. This continuous cycle separates the fine and coarse particles in the crushed finished material. The transfer pump then conveys the coarse particles to the asbestos recovery unit, where they are separated into fine-grained fibrous asbestos products. The column mill used is linear grinding, which can effectively protect the fiber structure in the raw material from being destroyed compared to the ball mill in the prior art, and the particle size distribution of the material is uniform.

[0014] Specifically, a first screw conveyor is provided at the bottom of the raw material bin, and the output end of the first screw conveyor is connected to the feed port of the column mill.

[0015] Specifically, the bottom of the asbestos recovery device is connected to the inlet of the second screw conveyor, the other end of the second screw conveyor is arranged at the bottom of the dust collector, and a first collection bin is provided at the outlet of the second screw conveyor.

[0016] Preferably, an air turbidity sensor is provided on the inner sidewall of the sifter or on the inner sidewall of the duct connecting the sifter and the dust collector. The air turbidity sensor is positioned above the screen and is electrically connected to the blower. When the turbidity detected by the air turbidity sensor is lower than a set value, indicating that the screen is filled with large particles, the blower stops operating. When the turbidity detected by the air turbidity sensor is higher than the set value, the blower operates normally.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. The asbestos tailings classification recovery system of the utility model realizes the comprehensive recovery of fine asbestos in asbestos tailings, which can meet the seventh-level asbestos product standard and reduce the impact on the subsequent comprehensive recovery of MgO and SiO2 in asbestos tailings.

[0019] 2. The asbestos tailings classification recovery system of the present invention adopts linear grinding in the column mill. Compared with the ball mill in the prior art, it effectively protects the fiber structure in the raw material from being destroyed, and the material particle size distribution is uniform.

[0020] 3. The asbestos tailings classification recovery system of the present invention adopts a combination of a screener and an air turbidity sensor to achieve separation of fine and coarse particles, thereby improving separation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of the asbestos screening device of the present utility model;

[0022] Figure 2 This is a schematic structural diagram of the asbestos tailings classification recovery system of the present utility model.

[0023] In the figure:

[0024] 1—Raw material silo; 2—First screw conveyor; 3—Column mill; 4—Sifter; 41—Screen; 42—Gravity hammer; 43—Feed inlet; 5—Conveying pump; 6—Asbestos recovery device; 7—Dust collector; 8—Second screw conveyor; 9—Induced draft fan; 10—Chimney; 11—Air turbidity sensor; 12—First collecting silo; 13—Blower; 14—Valve. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments and features of the embodiments of the present invention may be combined unless they conflict. For ease of description, the words "upper," "lower," "left," and "right" appear below merely to indicate the directions of upper, lower, left, and right in the accompanying drawings and do not limit the structure.

[0026] like Figure 1As shown, the asbestos screening device provided in this embodiment includes a dust collector 7 and a sifter 4 with an inner cavity. The top of the sifter 4 is connected to the dust collector 7 via a pipe. The dust collector 7 is a bag-type dust collector. An inlet 43 is provided on the side wall of the sifter 4. A screen 41 is provided along the inner wall of the sifter 4 along the cross-sectional direction. The screen 41 has a mesh size of 45 μm and a surface area larger than the cross-sectional area of the sifter 4. A gravity hammer 42 is provided on the screen 41. The screen 41 has a conical structure, with the large-diameter end of the cone connected to the inner wall of the sifter 4. The gravity hammer 42 is located at the small-diameter end of the cone, and the inlet 43 is located below the large-diameter end of the cone. An air turbidity sensor 11 is provided on the inner wall of the sifter 4, located above the screen 41. The bottom of the dust collector 7 is connected to the induced draft fan 9 through a pipeline, and the air outlet of the induced draft fan 9 is connected to the chimney 10.

[0027] like Figure 2 As shown, this embodiment also provides an asbestos tailings classification and recovery system comprising a raw material bin 1, a column mill 3, a delivery pump 5, an asbestos recovery device 6, and the asbestos screening device described above. The column mill 3 is equipped with a blower 13, which is electrically connected to an air turbidity sensor 11. A first screw conveyor 2 is located at the bottom of the raw material bin 1. The output end of the first screw conveyor 2 is connected to the feed inlet of the column mill 3, and the discharge of the column mill 3 is connected to the feed inlet 43 of the screener 4. The bottom of the screener 4 is connected to the inlet of the delivery pump 5, with a valve 14 installed at the connection point. The delivery pump 5 is used to transport the material at the bottom of the screener 4 to the asbestos recovery device 6 for classification and dust removal. The asbestos recovery device 6 uses a commercially available flat gyratory screen or flat shaking screen. The bottom of the asbestos recovery device 6 is connected to the feed inlet of a second screw conveyor 8. The other end of the second screw conveyor 8 is located at the bottom of a dust collector 7. A first collection bin 12 is located at the discharge of the second screw conveyor 8.

[0028] During operation, asbestos tailings are conveyed from the raw material bin 1 via the first screw conveyor 2 to the column mill 3. After grinding, the finished material has a particle size of approximately 74 μm. The blower 13 within the column mill 3 then conveys the material to the sifter 4. The wind forces the material to move, causing the screen 41 to bulge upward, forming a conical screen and driving the gravity hammer 42 upward. Ultrafine material passes through the screen 41 and moves upward into the dust collector 7, while coarse particles (50-74 μm) adhere to the screen. When the air turbidity sensor 11 detects turbidity below the designed value, it indicates that the screen 41 is filled with coarse particles (50-74 μm). At this point, the blower 13 within the column mill 3 stops supplying air, and the gravity hammer 42 tilts the screen 41 downward, discharging the coarse particles onto the bottom of the sifter 4. Simultaneously, the bottom valve 14 opens, discharging the coarse particles into the bottom delivery pump 5. After valve 14 at the bottom of screener 4 is closed, blower 13 in column mill 3 is activated to supply air. Simultaneously, gravity hammer 42 rises to form conical screen 41, continuously circulating to separate ultrafine and coarse materials. Coarse materials with a particle size of 50-74 μm are transported by pump 5 to asbestos recovery unit 6 for classification and dust removal, resulting in asbestos product. The coarse particles enter second screw conveyor 8 at the bottom, where they combine with the fine material to form granular material that enters first collection bin 12.

[0029] The contents described in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent modifications to the embodiments by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. An asbestos screening device, characterized in that: It comprises a dust collector (7) and a sifter (4) provided with an inner cavity, wherein the top of the sifter (4) is connected to the dust collector (7) through a pipeline; The side wall of the sifter (4) is provided with an inlet (43), and the material to be processed enters the inner cavity of the sifter (4) through the inlet (43) by pneumatic conveying; The inner side wall of the sifter (4) is provided with a screen (41) along the cross-sectional direction, and the screen (41) is arranged above the feed port (43); The surface area of the screen (41) is larger than the cross-sectional area of the sifter (4), and a gravity hammer (42) is provided on the screen (41).

2. The asbestos screening device according to claim 1, characterized in that: The mesh size of the sieve (41) is 45 to 60 μm.

3. The asbestos screening device according to claim 1, characterized in that: The screen (41) is a conical structure, the large diameter end of the conical structure is connected to the inner wall of the screener (4), the gravity hammer (42) is arranged on the small diameter end of the conical structure, and the feed port (43) is arranged below the large diameter end of the conical structure.

4. The asbestos screening device according to claim 1, characterized in that: An air turbidity sensor (11) is provided on the inner side wall of the sifter (4) or the inner side wall of the pipe connecting the sifter (4) and the dust collector (7). The air turbidity sensor (11) is arranged above the screen (41).

5. The asbestos screening device according to claim 1, characterized in that: The bottom of the dust collector (7) is connected to the induced draft fan (9) through a pipeline, and the air outlet of the induced draft fan (9) is connected to the chimney (10).

6. The asbestos screening device according to claim 1, characterized in that: The dust collector (7) is a bag-type dust collector.

7. An asbestos tailings classification recovery system, characterized by: The invention comprises a raw material bin (1), a column mill (3), a delivery pump (5), an asbestos recovery device (6) and an asbestos screening device as claimed in any one of claims 1 to 6, wherein the column mill (3) is provided with a blower (13); the discharge port of the raw material bin (1) is connected to the feed port of the column mill (3), and the discharge port of the column mill (3) is connected to the feed port (43) of the sifter (4); the bottom of the sifter (4) is connected to the inlet of the delivery pump (5), and a valve (14) is provided at the connection point, and the delivery pump (5) is used to transport the material in the sifter (4) to the asbestos recovery device (6) for graded recovery.

8. The asbestos tailings classification recovery system according to claim 7, characterized in that: A first screw conveyor (2) is provided at the bottom of the raw material bin (1), and the output end of the first screw conveyor (2) is connected to the feed port of the column mill (3).

9. The asbestos tailings classification recovery system according to claim 7, characterized in that: The bottom of the asbestos recovery device (6) is connected to the inlet of the second screw conveyor (8), the other end of the second screw conveyor (8) is arranged at the bottom of the dust collector (7), and a first collecting bin (12) is provided at the outlet of the second screw conveyor (8).

10. The asbestos tailings classification recovery system according to claim 7, characterized in that: An air turbidity sensor (11) is provided on the inner side wall of the screener (4) or the inner side wall of the pipe connecting the screener (4) and the dust collector (7). The air turbidity sensor (11) is arranged above the screen (41). The air turbidity sensor (11) is electrically connected to the blower (13).

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