Automatic coal floating and sinking device and method

Abstract

The present application relates to a kind of coal automatic big float and sink device and method, belong to coal sorting processing technical field, solve the long cycle, labor-intensive, poor safety problem caused by manual operation in prior art coal big float and sink test.The present application includes float and sink tank and excitation system, the excitation system includes first wedge-shaped magnetic pole and second wedge-shaped magnetic pole, the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole are symmetrically located at the two sides of the float and sink tank, multiple movable baffles are arranged in the float and sink tank, the movable baffle separates the float and sink tank into multiple float and sink bins, the distance between the float and sink bin and the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole gradually decreases from one end of the float and sink tank to the other end.The present application reduces the harm degree of heavy medium suspension to personnel, improves work safety, while the automatic float and sink process improves efficiency and reduces labor intensity.

Description

Technical Field

[0001] This invention relates to the field of coal sorting and processing technology, and in particular to an automatic large-scale coal flotation and sinking device and method. Background Technology

[0002] Coal preparation plants are places where valuable minerals and gangue minerals in coal are separated, with the aim of improving coal quality and utilization efficiency. Timely understanding of the density composition of raw coal and its various products is crucial for guiding the operation of sorting equipment. However, existing large-scale flotation and sedimentation methods suffer from problems such as complex procedures and the use of corrosive chemicals, making it impossible for many coal preparation plants to complete large-scale flotation and sedimentation tests. This results in decreased product yield and significant loss of coal resources.

[0003] The existing method for large-scale float-sink tests (for coal with a particle size greater than 0.5 mm) involves preparing heavy liquids of different densities using zinc chloride and water. Materials of various particle sizes greater than 0.5 mm are placed in a mesh bottom container, which is then placed in the lowest density heavy liquid container. The container is slowly moved up and down, allowing it to settle and separate into layers. Floating particles are scooped out with a ladle, while sinking particles are transferred to the next density heavy liquid container. This process is repeated until all densities are separated. Finally, the products of each density are rinsed with water to remove any remaining heavy liquid, then dried in an oven and weighed. Because current float-sink tests are entirely manual and involve only about 300 kg of coal per test, the process is complex, time-consuming, labor-intensive, and the manual operation often alters the float-sinking environment. Furthermore, zinc chloride is highly corrosive, and personnel are prone to injury from splashes during operation.

[0004] To reduce and avoid the above problems, and to enable coal preparation plants to understand the density composition of raw coal and various products in a timely manner to guide production, it is urgent to develop an automated large-scale floating and sinking device with a high degree of automation, wide adaptability, and no personal injury. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide an automatic coal floating and sinking device and method to solve the problems of long cycle, high labor intensity, and poor safety caused by the manual operation of existing coal floating and sinking tests.

[0006] On one hand, the present invention provides an automatic coal floating and sinking device, including a floating and sinking trough and an excitation system. The excitation system includes a first wedge-shaped magnetic pole and a second wedge-shaped magnetic pole, which are symmetrically located on both sides of the floating and sinking trough. The floating and sinking trough is provided with a plurality of movable baffles, which divide the floating and sinking trough into a plurality of floating and sinking chambers. The distance between the floating and sinking chambers and the first and second wedge-shaped magnetic poles gradually decreases from one end of the floating and sinking trough to the other end.

[0007] Furthermore, each of the floating and settling chambers is provided with a scraper structure at its upper part, which is used to scrape out the coal blocks that float to the upper part of the floating and settling chamber.

[0008] Furthermore, the scraper structure is a rectangular scraper or an irregularly shaped scraper. When the scraper structure is an irregularly shaped scraper, the irregularly shaped scraper includes a first rectangular plate and a second rectangular plate.

[0009] Furthermore, the floating and settling tank is provided with a discharge chute near the top of the first wedge-shaped magnetic pole, and the scraper structure is arranged near the discharge chute.

[0010] Furthermore, the bottom of the discharge chute is provided with a first channel, a second channel, and a third channel, with the second channel located between the first channel and the third channel.

[0011] Furthermore, the lower end of the first channel is connected to the lower part of the flotation tank via a circulating medium pipe.

[0012] Furthermore, the lengths of the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole are not less than the length of the flotation tank, and the heights of the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole are equal to the height of the liquid in the flotation tank.

[0013] Furthermore, the flotation chamber, which has the highest average density of the heavy medium suspension, is equipped with an elevable sieve plate.

[0014] Furthermore, the lower ends of the multiple floating and sinking chambers are connected.

[0015] On the other hand, the present invention provides an automatic large-scale floating and sinking method for coal, which uses the above-mentioned automatic large-scale floating and sinking device for coal to automatically float and sink.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] (1) The present invention has a first wedge-shaped magnetic pole and a second wedge-shaped magnetic pole symmetrically arranged on both sides of the floating and settling tank. The distance between the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole and the side wall of the floating and settling tank gradually decreases from one side of the tank to the other side. With the help of the wedge-shaped excitation system, a uniform magnetic field in one direction and a non-uniform magnetic field in the horizontal plane are generated, so that the heavy medium suspension filled with magnetite powder exhibits a concentration gradient in one direction, realizing the separation of multiple density levels in a floating and settling tank, effectively reducing the footprint, reducing the harm to personnel, and improving safety. With the help of movable baffles, variable suspension concentration and variable magnetic field strength, flexible density level adjustment can be achieved, improving the stability of the system.

[0018] (2) The floating and settling tank of the present invention is equipped with a rotatable screen plate. The rotatable screen plate swings back and forth within a certain range, so that the coal blocks falling on it can roll down to the next density area for sorting, realizing automatic continuous sorting of each density level and freeing up labor.

[0019] (3) The first channel of the discharge chute of the present invention is connected to the lower end of the floating and settling tank through a circulating medium pipe, which can circulate the heavy medium suspension scraped out by the scraper structure back into the floating and settling tank, thus ensuring the stability of the heavy medium suspension in the floating and settling tank.

[0020] (4) The rotatable screen plate of the present invention swings back and forth through a driving structure. When the first sector gear meshes with the second gear, the second sector gear does not mesh with the second gear. When the first sector gear disengages from the second gear and idles for a certain angle, the second sector gear meshes with the second gear. The first sector gear and the second sector gear alternately mesh with the second gear, causing the second gear to rotate back and forth, which in turn drives the first gear to rotate back and forth, realizing the back and forth swing of the rotatable screen plate. This allows the coal blocks falling onto the rotatable screen plate to roll smoothly to the next area for sorting, thus realizing the sorting of different density levels.

[0021] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0022] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0023] Figure 1 This is a schematic diagram of the structure of the automatic coal floating and sinking device according to a specific embodiment;

[0024] Figure 2 This is a cross-sectional schematic diagram of an automatic coal floating and sinking device according to a specific embodiment.

[0025] Figure 3 This is a schematic diagram of the rectangular scraper structure in a specific embodiment;

[0026] Figure 4 This is a schematic diagram of the irregularly shaped scraper structure in a specific embodiment;

[0027] Figure 5 This is a schematic diagram of the scraper structure formed by multiple rectangular scrapers in a specific embodiment;

[0028] Figure 6This is a schematic diagram of a scraper structure formed by multiple irregularly shaped scrapers in a specific embodiment.

[0029] Figure 7 This is a top view of a coal automatic large-scale floating and sinking device without an excitation system, according to a specific embodiment.

[0030] Figure 8 This is a schematic diagram of the discharge chute in a specific embodiment;

[0031] Figure 9 This is a schematic diagram of the forces acting on coal in a specific embodiment;

[0032] Figure 10 This is a schematic diagram of the driving structure in a specific embodiment.

[0033] Figure label:

[0034] 100-Floating and settling tank; 101-Modible baffle; 102-Floating and settling chamber; 103-Scraper structure; 104-First rotating shaft; 105-Discharge chute; 106-First rectangular plate; 107-Second rectangular plate; 108-Spray water device; 109-First channel; 110-Second channel; 111-Third channel; 112-Discharge screen plate; 113-Circulating medium pipe; 114-Discharge port; 115-Discharge valve; 116-Rotable screen plate; 117-Second rotating shaft; 118-Arc-shaped area; 119-Liftable screen plate;

[0035] 200 - Excitation system; 201 - First wedge-shaped magnetic pole; 202 - Second wedge-shaped magnetic pole; 300 - Feed pipe;

[0036] 400 - Drive structure; 401 - First gear; 402 - First combined gear; 403 - Second combined gear; 404 - Second gear; 405 - Third gear; 406 - First sector gear; 407 - Fourth gear; 408 - Second sector gear. Detailed Implementation

[0037] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0038] Example 1

[0039] A specific embodiment of the present invention, such as Figures 1-10 As shown, an automatic coal floating and sinking device is disclosed. See also Figure 1 and Figure 2As shown, the automatic coal floating and sinking device includes a floating and sinking tank 100 and an excitation system 200. The excitation system 200 includes a first wedge-shaped magnetic pole 201 and a second wedge-shaped magnetic pole 202. The first wedge-shaped magnetic pole 201 and the second wedge-shaped magnetic pole 202 are symmetrically located on both sides of the floating and sinking tank 100. The floating and sinking tank 100 is provided with multiple movable baffles 101. The movable baffles 101 are engaged with the inner wall of the floating and sinking tank 100. The multiple movable baffles 101 divide the floating and sinking tank 100 into multiple floating and sinking chambers 102. The lower ends of the floating and sinking chambers 102 are connected. The distance between the floating and sinking chamber 102 and the first wedge-shaped magnetic pole 201 and the second wedge-shaped magnetic pole 202 gradually decreases from one end of the floating and sinking tank 100 to the other end. The height of the first wedge-shaped magnetic pole 201 and the second wedge-shaped magnetic pole 202 is the same as the height of the liquid in the flotation tank 100. The length of the first wedge-shaped magnetic pole 201 and the second wedge-shaped magnetic pole 202 is not less than the length of the flotation tank 100, that is, the heavy medium suspension in the flotation tank 100 is within the range covered by the two wedge-shaped magnetic poles.

[0040] In practice, the heavy medium suspension is injected into the flotation tank 100. The magnetic field generated by the excitation system 200 makes one direction of the horizontal plane a uniform magnetic field and the other direction a non-uniform magnetic field, so that the heavy medium suspension filled with magnetite powder exhibits a concentration gradient in one direction. The flotation tank 100 is divided into multiple flotation chambers 102 by the movable baffle 101, so that the average density of the heavy medium suspension in each flotation chamber 102 is the required sorting density. At this time, the density of the heavy medium suspension in the flotation tank 100 gradually increases from one side to the other. That is, the average density of the heavy medium suspension in the multiple flotation chambers 102 is set in a gradient, which is inversely proportional to the distance between the excitation system 200 and the flotation tank 100. The area where the first wedge magnetic pole 201 and the second wedge magnetic pole 202 are closer to the flotation tank 100 has a large average density of heavy medium suspension, and the area where the first wedge magnetic pole 201 and the second wedge magnetic pole 202 are farther from the flotation tank 100 has a small average density of heavy medium suspension.

[0041] The preferred heavy medium in the heavy medium suspension is magnetite powder, with a particle size preferably below 200 mesh. Using magnetite powder suspension instead of zinc chloride as the heavy liquid can reduce the harm to the human body caused by the strong corrosiveness of zinc chloride, and also allows for the direct use of magnetite powder from the main washing system of the coal preparation plant.

[0042] Compared with the prior art, the automatic coal floating and sinking device provided in this embodiment has a first wedge-shaped magnetic pole 201 and a second wedge-shaped magnetic pole 202 symmetrically arranged on both sides of the floating and sinking tank 100. The distance between the first wedge-shaped magnetic pole 201 and the second wedge-shaped magnetic pole 202 and the side wall of the floating and sinking tank 100 gradually decreases from one side of the floating and sinking tank 100 to the other side. With the help of the wedge excitation system, a uniform magnetic field in one direction and a non-uniform magnetic field in the horizontal plane are generated, so that the heavy medium suspension filled with magnetite powder exhibits a concentration gradient in one direction, realizing the separation of multiple density levels within a floating and sinking tank 100, effectively reducing the floor space. With the help of the movable baffle 101, the variable suspension concentration, and the variable magnetic field strength, flexible density level adjustment can be achieved, improving the stability of the system.

[0043] After entering the floating and settling chamber 102, the coal block is subjected to gravity, buoyancy, and magnetic levitation. When the weight of the coal block is less than the buoyancy it experiences, the coal block will float. When the weight of the coal block is greater than the buoyancy it experiences, the coal block will sink. That is, the coal block will float when its density is lower than the density inside the floating and settling chamber 102, and will sink when its density is higher than the density inside the floating and settling chamber 102.

[0044] Because coal blocks with a density greater than the average density of the heavy medium suspension will float to the top of the floating and settling tank 102 in the floating and settling tank 102, that is, high-density coal blocks will gather upwards to the surface of the liquid in the floating and settling tank 102, a scraper structure 103 is provided in the floating and settling tank 100 to facilitate the discharge of coal blocks.

[0045] A scraper structure 103 is located at the top of the flotation tank 100. Each flotation chamber 102 contains a scraper structure 103. A first rotating shaft 104 is located at the top of the flotation tank 100. The first rotating shaft 104 passes through the side wall of the flotation tank 100 and through the movable baffle 101. Bearings are provided at the connection points between the first rotating shaft 104 and the side wall of the flotation tank 100 and the movable baffle 101. Through holes are provided on the side wall of the flotation tank 100 and the movable baffle 101, and bearings are located in the through holes. The first rotating shaft 104 is connected to the bearings.

[0046] like Figure 3 As shown, the scraper structure 103 is a rectangular scraper. Considering the connection between the scraper structure 103 and the first rotating shaft 104, a through hole is provided in the middle along the thickness direction of the rectangular scraper. The through hole is consistent with the length or width direction of the rectangular scraper. The first rotating shaft 104 passes through the through hole of the rectangular scraper and is connected to the rectangular scraper by a key, so that the rectangular scraper rotates synchronously with the first rotating shaft 104. It should be noted that the thickness of the rectangular scraper is less than its length and width.

[0047] The first rotating shaft 104 is connected to the first motor, which is located on the outer side wall of the flotation tank 100. The first motor drives the first rotating shaft 104 to rotate, which in turn drives the rectangular scraper to rotate. Since the part of the rectangular scraper below the first rotating shaft 104 in the vertical state is submerged in the heavy medium suspension, the rectangular scraper will push the coal blocks that have floated to the top of the flotation tank 102 to the side of the flotation tank 102 closer to the first wedge-shaped magnetic pole 201 or the second wedge-shaped magnetic pole 202 during rotation. Figure 7 As shown, a discharge chute 105 is provided on the side of the flotation chamber 102 near the first wedge-shaped magnetic pole 201 or the second wedge-shaped magnetic pole 202. The ore scraped out by the rectangular scraper during rotation falls into the discharge chute 105.

[0048] It is worth noting that each floating and settling tank 102 is provided with a scraper structure 103 at its upper part. The scraper structure 103 rotates along a horizontal axis. All the scraper structures 103 in the floating and settling tanks 102 can be connected to a horizontal axis and driven to rotate simultaneously by a motor. Alternatively, each scraper structure 103 in the floating and settling tank 102 can be controlled by a motor. In this case, each scraper structure 103 is connected to an independent horizontal axis.

[0049] To increase the scraping efficiency of the scraper structure 103 on the coal blocks that float above the floating bin 102, such as Figure 4 As shown, the scraper structure 103 is an irregularly shaped scraper, that is, the scraper structure 103 is formed by connecting two rectangular plates. For ease of description, the two rectangular plates are defined as the first rectangular plate 106 and the second rectangular plate 107. The first rectangular plate 106 and the second rectangular plate 107 have the same length, and the width of the second rectangular plate 107 is less than the width of the first rectangular plate 106. The first rectangular plate 106 is connected to the first rotating shaft 104, and the second rectangular plate 107 is connected to one end of the first rectangular plate 106. The included angle between the second rectangular plate 107 and the first rectangular plate 106 is not equal to 90 degrees to avoid ore being left on the second rectangular plate 107. The surface of the first rectangular plate 106 and the second rectangular plate 107 with an included angle of less than 180° is used to scrape out the ore.

[0050] To further improve the ore scraping efficiency, the scraper structure 103 includes at least two rectangular scrapers that are cross-connected. For example, when the scraper structure 103 is formed by two rectangular scrapers, the two rectangular scrapers intersect in a cross shape; when the scraper structure 103 is formed by three rectangular scrapers, as... Figure 5 As shown, three rectangular scrapers intersect in an "*" shape, and so on. Multiple rectangular scrapers in scraper structure 103 alternately enter the heavy medium suspension to scrape out the ore, which is more efficient than a single rectangular scraper. It should be noted that, as... Figure 6 As shown, the scraper that makes up the scraper structure 103 can also be an irregular scraper formed by two rectangular plates.

[0051] Considering that the scraper structure 103 will carry out some heavy medium suspension during the scraping of ore, in order to reduce the scraping of heavy medium suspension, the rectangular scraper or the second rectangular plate is provided with water filter holes. When the scraper structure 103 scrapes out ore, some heavy medium suspension flows out from the water filter holes, which reduces the resistance of the scraper structure 103 and also reduces the amount of heavy medium suspension scraped out in the flotation tank 102, thus ensuring the stability of the heavy medium suspension.

[0052] It should be noted that, in order to facilitate the scraping out of the ore that floats to the top of the settling tank 102, the scraper structure 103 is located near the discharge chute 105, rather than in the middle of the settling tank 102.

[0053] like Figure 7 As shown, the number of discharge chutes 105 is the same as the number of flotation tanks 102. Each flotation tank 102 has a discharge chute 105 on one side of its upper end. In this embodiment, the discharge chutes 105 are located near the first wedge-shaped magnetic pole 201. The ore scraped out by the scraper structure 103 (with a small amount of heavy medium suspension) enters the discharge chutes 105.

[0054] Considering that the ore scraped by the scraper structure 103 has some heavy medium suspension attached, such as Figure 8 As shown, a spray water device 108 is provided in the discharge chute 105. The spray water device 108 cleans the ore with heavy medium suspension adhering to it as it enters the discharge chute 105. In this embodiment, by cleaning the ore with heavy medium suspension adhering to it using the spray water device 108, a cleaner ore can be obtained, avoiding the impact of the adhering heavy medium suspension on the quality of the ore.

[0055] Considering the discharge of ore, scrubbing water, and heavy media suspension, the discharge chute 105 has three channels: the first channel 109, the second channel 110, and the third channel 111. All three channels are located at the bottom of the discharge chute 105. The second channel 110 is located between the first channel 109 and the third channel 111. The first channel 109 is located directly below the inlet of the discharge chute 105, that is, below the position where the ore scraped by the scraper structure 103 just enters the discharge chute 105.

[0056] A discharge screen 112 is installed at the entrances of the first channel 109 and the second channel 110. The discharge screen 112 is inclined, with the inlet of the first channel 109 higher than the inlet of the second channel 110. The discharge screen 112 gradually decreases in height from the first channel 109 to the second channel 110. The ore scraped off by the scraper structure 103 enters the discharge chute 105 and rolls downwards on the discharge screen 112. The heavy medium suspension scraped along with the ore leaks off the discharge screen 112 and is discharged through the first channel 109. A spray water device 108 in the discharge chute 105 sprays water to wash the ore that rolls down to the second channel 110. The spray water and the heavy medium suspension washed off the ore enter the second channel 110 together. The lower end of the second channel 110 is connected to a recovery tank. The ore washed by the spray water device 108 rolls down to the third channel 111 and is discharged. Understandably, the spray water device 108 is located directly above the second channel 110. The spray water device 108 washes away the heavy medium suspension that adheres to the surface of the ore to avoid affecting product quality.

[0057] Considering the stability of the heavy medium suspension in the flotation chamber 102, such as Figure 1 and Figure 2 As shown, each floating and settling tank 102 has a circulating medium pipe 113 on its side wall. The circulating medium pipe 113 and the discharge chute 105 are located on the same side of the floating and settling tank 102. The upper end of the circulating medium pipe 113 is connected to the lower end of the first channel 109. The lower end of the circulating medium pipe 113 is connected to the lower part of the floating and settling tank 102 through a pump.

[0058] In this embodiment, the first channel 109 at the lower end of the discharge chute 105 is connected to the circulating medium pipe 113. The heavy medium suspension scraped out of the flotation and settling tank 102 by the scraper structure 103 enters the discharge chute 105, passes through the first channel 109, enters the circulating medium pipe 113, and finally returns to the flotation and settling tank 102 to maintain the stability of the heavy medium suspension in the vertical direction. At the same time, when the scraper structure 103 is provided with filter holes, the amount of heavy medium suspension scraped out is reduced, which can also ensure the stability of the heavy medium suspension in the flotation and settling tank 102.

[0059] To facilitate the transport of coal to the flotation tank 100, the automatic large flotation device for coal also includes a feed pipe 300. The feed pipe 300 is connected to the flotation tank 100. The upper end of the feed pipe 300 is higher than the liquid level in the flotation tank 100. The lower end of the feed pipe 300 is inserted into the flotation chamber 102 with the lowest average density of the heavy medium suspension and is close to the movable baffle 101 to ensure that the feed pressure will not affect the coal sorting in the flotation chamber 102 (with the lowest average density of the heavy medium suspension) and that the coal blocks will not enter the next sorting area (flotation chamber 102) due to the feed pressure.

[0060] After multiple sorting processes, the amount of coal slime in the heavy medium suspension in the settling tank 100 becomes excessive, causing a decrease in the density of the heavy medium suspension. Therefore, it is necessary to replace it with a new heavy medium suspension. Figure 1 As shown, the lower part of the flotation tank 100 is provided with a discharge port 114, and a discharge valve 115 is provided on the discharge port 114. The discharge valve 115 controls the opening and closing of the discharge port 114.

[0061] Considering that coal enters the flotation chamber 102 with the lowest average density of the heavy medium suspension through the feed pipe 300, and the average density of the heavy medium suspension in each flotation chamber 102 is set in a gradient, for example, the movable baffle 101 divides the flotation tank 100 into 5 flotation chambers 102 with densities of 1.3 g / cm³. 3 1.4g / cm 3 1.5g / cm 3 1.6g / cm 3 and 1.8g / cm 3 The coal was first transported to a heavy medium suspension with an average density of 1.3 g / cm³. 3 In the floating and settling chamber 102, at a density of 1.3 g / cm³, 3 The density of the coal lumps in the sinking chamber 102 is less than 1.3 g / cm³. 3 If the coal floats, it will rise; otherwise, it will sink to the bottom of the flotation chamber 102. Coal pieces that sink to the bottom of the flotation chamber 102 need to be transported to the next density level flotation chamber 102 for sorting. Therefore, if... Figure 1 As shown, except for the settling tank 102 with the highest average density of the heavy medium suspension, all other settling tanks 102 share a common rotating screen plate 116. The rotating screen plate 116 is inclined in the settling tank 100, resulting in a trend where the settling tank 102 with the lowest average density of the heavy medium suspension has a higher screen plate, and the settling tank 102 with the highest average density of the heavy medium suspension has a lower screen plate. By utilizing the gravity of the ore and the back-and-forth rotation of the rotating screen plate 116, automatic and continuous sorting of various density levels is achieved, freeing up labor.

[0062] The rotatable screen plate 116 is a rectangular plate. When the rotatable screen plate 116 is in an inclined state, second rotating shafts 117 are provided on both sides of its lower end. The second rotating shafts 117 pass through the side walls of the flotation tank 100 and form a rotational seal with the side walls of the flotation tank 100. The rotatable screen plate 116 rotates up and down about the second rotating shafts 117 as its rotation axis. Figure 9 As shown, the angle between the rotatable sieve plate 116 and the horizontal plane is θ, and θ satisfies the following formula:

[0063] θ>arc tan[(G-f1) / f2]

[0064] Where G represents the weight of the coal block, f1 represents the buoyancy of the coal block in the heavy medium suspension, and f2 represents the magnetic buoyancy of the coal block in the heavy medium suspension.

[0065] Considering that the rectangular rotatable screen plate 116 follows an arc trajectory during rotation, to prevent gaps from forming between the rotatable screen plate 116 and the side wall of the flotation chamber 102 (where the average density of the heavy medium suspension is lowest), causing coal to leak below the rotatable screen plate 116, as follows: Figure 1 As shown, the side wall (the wall parallel to the second rotating shaft 117) of the settling tank 102, which has the lowest average density of heavy medium suspension, is provided with an outwardly convex arc-shaped area 118. The outwardly convex arc-shaped area 118 is a protruding part of the settling tank 100. The free end of the rotatable screen plate 116 (the end opposite to the one with the second rotating shaft 117) is located in the outwardly convex arc-shaped area 118. During the rotation of the rotatable screen plate 116, it can avoid the gap between it and the vertical side wall of the settling tank 102, which would cause coal blocks to leak to the bottom of the rotatable screen plate 116.

[0066] like Figure 10 As shown, the automatic coal flotation and settling device also includes a drive mechanism 400 for the rotatable screen plate 116 to swing back and forth. The drive mechanism 400 includes a first gear 401, a first combined gear 402, a second combined gear 403, and a second gear 404. The first gear 401 is connected to the second rotating shaft 117 and meshes with the second gear 404. The rotation of the second gear 404 drives the first gear 401 to rotate. The rotation of the first gear 401 can drive the second rotating shaft 117 to rotate, thereby causing the rotatable screen plate 116 to swing back and forth, so that the coal blocks deposited on the rotatable screen plate 116 can smoothly roll down to the next flotation and settling chamber 102 for sorting.

[0067] The first combined gear 402 includes a third gear 405 and a first sector gear 406. The first sector gear 406 is located on one side of the third gear 405 and rotates synchronously with the third gear 405. The first sector gear 406 can mesh with the second gear 404. The second combined gear 403 includes a fourth gear 407 and a second sector gear 408. The second sector gear 408 is located on one side of the fourth gear 407 and rotates synchronously with the fourth gear 407. The second sector gear 408 can mesh with the second gear 404. The motor drives the first combined gear 402 or the second combined gear 403 to rotate, which in turn drives the second gear 404 to rotate back and forth. The back and forth rotation of the second gear 404 drives the back and forth rotation of the first gear 401, which in turn drives the rotatable screen plate 116 to swing back and forth.

[0068] It is worth noting that when the first sector gear 406 meshes with the second gear 404, the second sector gear 408 does not mesh with the second gear 404. After the first sector gear 406 and the second gear 404 disengage and idle for a certain angle, the second sector gear 408 meshes with the second gear 404. The first sector gear 406 and the second sector gear 408 alternately mesh with the second gear 404, causing the second gear 404 to rotate back and forth, which in turn drives the first gear 401 to rotate back and forth, thus realizing the back and forth swing of the rotatable screen plate 116.

[0069] Since high-density coal blocks will accumulate in the settling chamber 102 with the highest average density of the heavy medium suspension after flotation, a liftable screen plate 119 is provided in the settling chamber 102 to discharge the coal blocks accumulated therein. The liftable screen plate 119 is connected to a sprocket located above the settling tank 100 via a chain. The lifting chain can lift the high-density coal blocks located on the liftable screen plate 119 to the upper part of the settling chamber 102. With the rotation of the scraper structure 103, the ore can be scraped out of the settling chamber 102.

[0070] Example 2

[0071] Another specific embodiment of the present invention, such as Figures 1-10 As shown, an automatic coal floating and sinking method is disclosed, which uses the automatic coal floating and sinking device of Example 1. The steps include:

[0072] Step 1: Inject heavy medium suspension into the flotation tank 100. Under the action of the excitation system 200, the concentration of the heavy medium suspension is set in a gradient. Insert the movable baffle 101 to divide the flotation tank 100 into multiple flotation chambers 102 with the average concentration of heavy medium suspension set in a gradient.

[0073] A magnetite powder suspension of a certain density is injected into the flotation tank 100 through the feed pipe 300. Under the action of the excitation system 200, the generated magnetic field makes one direction of the horizontal plane a uniform magnetic field and the other direction a non-uniform magnetic field, so that the heavy medium suspension filled with magnetite powder exhibits a concentration gradient in one direction. Multiple flotation chambers 102 are obtained by separating the flotation tank 100 through the movable baffle 101. The average concentration of the heavy medium suspension in the multiple flotation chambers 102 is set in a gradient.

[0074] Step 2: Coal blocks are fed into the flotation chamber 102 with the lowest average density of the heavy medium suspension for sorting. At the same time, the circulating medium system is started. Coal blocks that float to the top of the flotation chamber 102 are scraped off by the scraper structure 103, and coal blocks that sink to the rotatable screen plate 116 roll to the next stage flotation chamber 102 with the lowest average density of the heavy medium suspension for sorting. This cycle is repeated to achieve the separation of coal of all density grades.

[0075] Subsequently, coal blocks are pumped from the feed pipe 300 into the settling chamber 102, which has the lowest average density of the heavy medium suspension. The feed pipe 300 extends into the settling chamber 102, maintaining a relatively close distance from the movable baffle 101 to ensure that the feed pressure does not affect the sorting in the settling chamber 102 and that the coal blocks enter the next settling chamber 102 due to the feed pressure. After entering the settling chamber 102, the coal blocks are subjected to gravity, buoyancy, and magnetic levitation. When the weight of the coal block is less than the buoyancy, the coal block will float, and vice versa. That is, coal blocks with a density lower than the average density of the heavy medium suspension in the settling chamber 102 will float, and coal blocks with a density higher than the average density of the heavy medium suspension in the settling chamber 102 will sink. After reaching the surface, the floating coal blocks are discharged through the scraper structure 103 and enter the discharge chute 105, which is equipped with a discharge screen plate 112 and a spray water device 108, for heavy medium suspension recovery and product desliming. The sinking coal chunks settle onto the bottom rotating screen plate 116 and roll to the next density zone by gravity. This cycle repeats, achieving separation of all density levels. It should be noted that the rotating screen plate 116 is swinging back and forth during this process.

[0076] While the coal block is being introduced, the circulating medium system is started. The heavy medium suspension in each flotation chamber 102 and the heavy medium suspension recovered in each discharge chute 105 (without added spray water) are pumped into the lower part of the tank. The purpose is to maintain the stability of the heavy medium suspension in the sorting system, replenish the medium, and disperse the bed.

[0077] Step 3: After sorting is completed, the liftable screen plate 119 is activated to lift the sediment in the floating and settling tank 102 with the highest average density of the heavy medium suspension to the upper part of the floating and settling tank 102 and discharge it through the scraper structure 103, thus completing the floating and settling process.

[0078] The lifting screen plate 119 is activated to lift the highest density sediment and discharge it through the scraper structure 103, thus completing the entire floating and sinking process.

[0079] It is worth noting that in step 3, after multiple separations, the amount of coal slime in the heavy medium suspension is relatively large, which leads to a decrease in the suspension density. The discharge valve 115 is opened and the heavy medium suspension is discharged through the discharge port 114. In addition, the discharged heavy medium suspension can be purified by a magnetic separator.

[0080] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic coal floating and sinking device, characterized in that, The device comprises a sink-and-float tank, an excitation system and a driving mechanism, the excitation system comprises a first wedge-shaped magnetic pole and a second wedge-shaped magnetic pole, the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole are symmetrically located on both sides of the sink-and-float tank, a plurality of movable baffles are arranged in the sink-and-float tank, the movable baffles separate the sink-and-float tank into a plurality of sink-and-float bins, the lower ends of the plurality of sink-and-float bins are communicated, the distance between the sink-and-float bins and the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole gradually decreases from one end of the sink-and-float tank to the other end, the excitation system generates a uniform magnetic field in one direction and a non-uniform magnetic field in the other direction in the horizontal plane, so that the heavy medium suspension filled with magnetite powder exhibits a concentration gradient in one direction; the average density of the heavy medium suspension in the plurality of sink-and-float bins is set in a gradient, and is inversely proportional to the distance of the excitation system from the sink-and-float tank; In addition to the sink-and-float bin with the highest average density of heavy medium suspension, a rotatable sieve plate is arranged in the other sink-and-float bins, the rotatable sieve plate is arranged in an inclined state in the sink-and-float tank, and presents a trend that the sink-and-float bin with a low average density of heavy medium suspension is high and the sink-and-float bin with a high average density of heavy medium suspension is low; the lower end of the rotatable sieve plate in the inclined state is provided with a second rotating shaft, and the rotatable sieve plate rotates up and down with the second rotating shaft as the rotating shaft, and the driving mechanism drives the rotatable sieve plate to swing back and forth.

2. The automatic coal floating and sinking device according to claim 1, characterized in that, An upper portion of each sink-and-float bin is provided with a scraper structure, and the scraper structure is used to scrape out the coal blocks floating to the upper portion of the sink-and-float bin.

3. The automatic coal floating and sinking device according to claim 2, characterized in that, The scraper structure is a rectangular scraper or a special-shaped scraper, and when the scraper structure is a special-shaped scraper, the special-shaped scraper comprises a first rectangular plate and a second rectangular plate.

4. The automatic coal floating and sinking device according to claim 2, characterized in that, A discharge chute is arranged at the top of the sink-and-float bin close to the first wedge-shaped magnetic pole, and the scraper structure is arranged close to the discharge chute.

5. The automatic coal floating and sinking device according to claim 4, characterized in that, A first channel, a second channel and a third channel are arranged at the bottom of the discharge chute, and the second channel is located between the first channel and the third channel.

6. The automatic coal floating and sinking device according to claim 5, characterized in that, The lower end of the first channel is communicated with the lower portion of the sink-and-float bin through a circulating medium pipe.

7. The automatic coal floating and sinking device according to any one of claims 1-6, characterized in that, The length of the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole is not less than the length of the sink-and-float tank, and the height of the first wedge-shaped magnetic pole and the second wedge-shaped magnetic pole is equal to the height of the liquid in the sink-and-float tank.

8. The automatic coal floating and sinking device according to any one of claims 1-6, characterized in that, A liftable sieve plate is arranged in the sink-and-float bin with the largest average density of heavy medium suspension.

9. An automatic coal floating and sinking method, characterized by, The coal automatic large sink-and-float device is used for coal automatic large sink-and-float.

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