Parallel two-stage fluidized flotation device and method suitable for fluctuating feed

Abstract

The present application relates to a kind of parallel two-stage fluidization flotation device and method suitable for fluctuation incoming material, belong to mineral separation technical field, solve the problem that the adaptability of coarse particle fluidization flotation device and method in prior art is poor when the property of incoming material exists greater fluctuation, it is difficult to realize product quality standard and valuable component recovery maximization.This application includes first flotation column and second flotation column, first flotation column and second flotation column are arranged in parallel, first flotation column includes first clean coal tank, first flotation column body and first tail coal cone, first clean coal tank and first tail coal cone are respectively arranged at the upper and lower sides of first flotation column body, second flotation column includes second incoming material pipe and second flotation column body, second incoming material pipe is arranged above second flotation column body, first clean coal tank and first tail coal cone are communicated with second incoming material pipe.This application realizes the formation of "roughing + cleaning" and "roughing + scavenging" two kinds of separation modes in the same device, to separate poor coal quality coarse slime in "roughing + cleaning" mode, to separate good coal quality coarse slime in "roughing + scavenging" mode, to cope with different nature of selected coarse slime, so as to be more suitable for coal quality fluctuation incoming coal flow.

Description

Technical Field

[0001] This invention relates to the field of mineral sorting technology, and more particularly to a parallel two-stage fluidized bed flotation apparatus and method suitable for fluctuating feed. Background Technology

[0002] Coal resources are an important source of raw materials for many fields such as chemical industry, power, metallurgy, and pharmaceuticals. The clean and efficient utilization of coal resources is of great significance.

[0003] The prerequisite for the clean and efficient utilization of coal resources is the enrichment of valuable components in the coal particles. In coal separation, gravity separation is effective for lump and fine coal, and flotation is effective for fine coal slime, and gravity and flotation technologies are becoming increasingly mature. However, the efficient separation of coarse coal slime (particle size 0.5-3.0 mm) faces challenges such as low recovery rate of flotation technology and low selectivity of gravity separation technology.

[0004] Coarse-grained fluidized bed flotation technology based on gravity-flotation coupling offers the possibility of efficient separation of coarse coal slime. Unlike traditional flotation technologies, fluidized bed flotation technology, through the construction of a low-turbulence, high-phase-content environment within the separation flow field, greatly inhibits the desorption of coarse coal slime particles adhering to bubbles. At the same time, the introduction of a stable upward flow rich in microbubbles also achieves effective coupling between gravity separation technology based on density and flotation technology based on particle surface properties, thus facilitating the efficient separation of coarse coal slime.

[0005] Existing fluidized bed flotation devices and methods are generally single-stage separation, with relatively fixed flow field environment and product characteristics. However, in actual industrial production, due to changes in coalfield mining faces and the characteristics of certain mining sections, the properties of the feed may change significantly at a certain time and last for a long period of time. Traditional single-stage fluidized bed flotation devices cannot simultaneously guarantee the quality of clean coal and tailings products, nor can they be flexible in responding to changes in feed properties. This can easily lead to problems such as substandard clean coal product quality or waste of valuable components.

[0006] It is evident that designing a parallel two-stage fluidized bed flotation device and method suitable for fluctuating feed, and selecting different separation modes according to different feed properties for unstable feed, thereby achieving efficient separation and recovery of coarse coal slime, is of great significance for low-energy separation of coarse coal slime. Summary of the Invention

[0007] Based on the above analysis, the present invention aims to provide a parallel two-stage fluidized bed flotation device and method suitable for fluctuating feed materials, in order to solve the problem that existing coarse-grained fluidized bed flotation devices and methods are not adaptable to large fluctuations in feed properties, making it difficult to achieve product quality standards and maximize the recovery rate of valuable components.

[0008] On one hand, the present invention provides a parallel two-stage fluidized bed flotation device suitable for fluctuating feed, including a first flotation column and a second flotation column, the first flotation column and the second flotation column are arranged in parallel, the first flotation column includes a first clean coal trough, a first flotation column body and a first tailings cone, the first clean coal trough and the first tailings cone are respectively disposed on the upper and lower sides of the first flotation column body, the second flotation column includes a second feed pipe and a second flotation column body, the second feed pipe is disposed above the second flotation column body, and the first clean coal trough and the first tailings cone are both connected to the second feed pipe.

[0009] Furthermore, the first flotation column is placed side by side with the second flotation column, and the second flotation column is lower than the first flotation column.

[0010] Furthermore, the first flotation column also includes a first fluid distributor, which is located between the first flotation column body and the first tailings cone.

[0011] Furthermore, the first flotation column also includes a first feed pipe and a first feed distributor, the first feed distributor being disposed within the first flotation column body and connected to the lower end of the first feed pipe.

[0012] Furthermore, the first flotation column also includes a clean coal spray pipe, which is located at the upper end of the first clean coal trough.

[0013] Furthermore, it also includes a first microbubble generator connected in communication with the first fluid distributor.

[0014] Furthermore, the second flotation column also includes a second clean coal trough and a second tail coal cone, which are respectively located on the upper and lower sides of the second flotation column.

[0015] Furthermore, the second flotation column also includes a second fluid distributor located between the second flotation column and the second tailings cone.

[0016] Furthermore, it also includes a second microbubble generator connected in communication with the second fluid distributor.

[0017] On the other hand, the present invention provides a parallel two-stage fluidized bed flotation method suitable for fluctuating feed, which uses the above-mentioned parallel two-stage fluidized bed flotation device suitable for fluctuating feed for flotation.

[0018] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0019] (1) By setting up a two-stage fluidized flotation system, the present invention can adjust the flow velocity of the rising water in the first and second flotation columns by controlling the fluid flow rate in the first and second microbubble generators. This allows for the construction of two low-turbulence, high-phase flow field environments with different rising water flow velocities within a single device. The low-velocity flow field can be used to recover low-ash clean coal from coarse coal slime feed to ensure the quality of clean coal. The high-velocity flow field is used to recover high-ash tailings particles to ensure recovery rate and tailings ash content, effectively guaranteeing product quality.

[0020] (2) By arranging the T-shaped second feed pipe, the first clean coal solenoid valve, the second clean coal solenoid valve, the T-shaped tail coal pipe, the first tail coal solenoid valve, the second tail coal solenoid valve, and the slurry pump, the present invention realizes the formation of two sorting modes in the same device: "roughing + fine selection" and "roughing + scavenging". The "roughing + fine selection" mode sorts the coarse coal slime with poor coal quality, and the "roughing + scavenging" mode sorts the coarse coal slime with better coal quality. This is to cope with different properties of the coarse coal slime and thus better adapt to the coal flow with fluctuating coal quality.

[0021] (3) The present invention introduces a large number of microbubble groups required for fluidization into the first flotation column and the second flotation column through the first microbubble generator and the second microbubble generator respectively. With the help of the first fluid distributor and the second fluid distributor, and with the assistance of the first flow stabilizer and the second flow stabilizer, a flotation flow field environment with low fluid disturbance and high microbubble content is constructed in the first flotation column and the second flotation column respectively, which effectively suppresses the turbulent dissipation of the flow field and is more conducive to the fluidization flotation recovery of coarse minerals.

[0022] (4) By producing three products—clean coal, middlings coal, and tailings coal—this invention effectively ensures the quality requirements of clean coal products while avoiding problems such as excessively low ash content in tailings coal, which could lead to the loss of valuable components, thus ensuring a high recovery rate of valuable components.

[0023] 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

[0024] 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.

[0025] Figure 1 This is a schematic diagram of the structure of a parallel two-stage fluidized bed flotation device according to a specific embodiment;

[0026] Figure 2This is a top view of the structure of the first fluid distributor in a specific embodiment;

[0027] Figure 3 For specific embodiments Figure 2 AA sectional view;

[0028] Figure 4 For specific embodiments Figure 2 BB cross-sectional diagram;

[0029] Figure 5 This is a top view of the structure of the second fluid distributor in a specific embodiment;

[0030] Figure 6 For specific embodiments Figure 5 CC cross-sectional view;

[0031] Figure 7 For specific embodiments Figure 5 DD cross-sectional view.

[0032] Figure label:

[0033] 100-First flotation column; 101-First clean coal trough; 102-First flotation column body; 103-First tailings cone; 104-First fluid distributor; 105-First annular water tank; 106-First rectangular water tank; 107-First U-shaped water tank; 108-First fluid distribution plate; 109-First water injection pipe; 110-First feed pipe; 111-First feed distributor; 112-Clean coal spray pipe; 113-First clean coal overflow pipe; 114-First clean coal solenoid valve; 115-T-shaped tailings pipe; 116-First tailings solenoid valve; 117-Second tailings solenoid valve; 118-First flow stabilizer plate;

[0034] 200-Second flotation column; 201-Second feed pipe; 202-Second flotation column body; 203-Second clean coal trough; 204-Second tailings cone; 205-Second fluid distributor; 206-Second annular water tank; 207-Second rectangular water tank; 208-Second U-shaped water tank; 209-Second fluid distribution plate; 210-Second water injection pipe; 211-Second feed distributor; 212-Second clean coal overflow pipe; 213-Second clean coal solenoid valve; 214-Second tailings pipe; 215-Second flow stabilizer plate;

[0035] 300 - First microbubble generator; 400 - Second microbubble generator; 500 - Slurry pump. Detailed Implementation

[0036] 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.

[0037] Example 1

[0038] A specific embodiment of the present invention, such as Figure 1 As shown, a parallel two-stage fluidized bed flotation device suitable for fluctuating feed is disclosed, including a first flotation column 100 and a second flotation column 200. The first flotation column 100 and the second flotation column 200 are arranged in parallel. The first flotation column 100 includes a first clean coal trough 101, a first flotation column body 102 and a first tailings cone 103. The first clean coal trough 101 and the first tailings cone 103 are respectively located on the upper and lower sides of the first flotation column body 102. The second flotation column 200 includes a second feed pipe 201 and a second flotation column body 202. The second feed pipe 201 is located above the second flotation column body 202. The first clean coal trough 101 and the first tailings cone 103 are both connected to the second feed pipe 201.

[0039] Compared with the prior art, the parallel two-stage fluidized bed flotation device provided in this embodiment has the first clean coal trough 101 and the first tailings cone 103 both connected to the second feed pipe 201. This allows the parallel two-stage fluidized bed flotation device to have two options: the concentrate from the overflow trough of the first flotation column 100 is fed into the second flotation column 200 for further flotation, or the underflow from the first flotation column 100 is fed into the second flotation column 200 for further flotation. This enables a single device to adapt to the separation of different feed properties. By selectively opening and closing valves, the device can select between two modes: "roughing + cleaning" and "roughing + scavenging" to adapt to possible changes in the properties of the feed material during the separation process.

[0040] In this embodiment, as Figure 1 As shown, the first flotation column 102 is placed side by side with the second flotation column 202, and the second flotation column 202 is lower than the first flotation column 102.

[0041] like Figure 1 As shown, the first flotation column 100 also includes a first fluid distributor 104, which is located between the first flotation column 102 and the first tailings cone 103. That is, the first clean coal trough 101, the first flotation column 102, the first fluid distributor 104 and the first tailings cone 103 are arranged sequentially from top to bottom.

[0042] In this embodiment, the first clean coal trough 101 is located at the top of the first flotation column 102 and is used to collect clean coal. The first fluid distributor 104 is located at the bottom of the first flotation column 102 and is used to supply fluidizing water into the first flotation column 102, thereby creating a low-turbulence, high-phase-content flow field environment. The first tailings cone 103 is located at the bottom of the first fluid distributor 104 and is used to collect tailings.

[0043] like Figure 2As shown, the first fluid distributor 104 includes a first annular water tank 105 and a plurality of first rectangular water tanks 106. The plurality of first rectangular water tanks 106 are arranged parallel to each other in the inner ring of the first annular water tank 105 and are in communication with the first annular water tank 105. Specifically, both ends of the first rectangular water tanks 106 are in communication with the first annular water tank 105. Preferably, the plurality of first rectangular water tanks 106 are arranged at equal intervals within the first annular water tank 105. The two ends of the first rectangular water tanks 106 are welded and fixed to the first annular water tank 105.

[0044] Furthermore, such as Figure 3 and Figure 4 As shown, the first rectangular water tank 106 includes a first U-shaped water tank 107 and a first fluid distribution plate 108. The first fluid distribution plate 108 is located at the opening of the first U-shaped water tank 107. The fluidized water entering the first U-shaped water tank 107 enters the first flotation column 102 through the first fluid distribution plate 108, forming a low-turbulence, high-phase-content flow field environment in the first flotation column 102.

[0045] Considering the need to inject fluidizing water into the first annular water tank 105, such as Figure 2 and Figure 3 As shown, the first fluid distributor 104 also includes two first water injection pipes 109, which are symmetrically located on both sides of the first annular water tank 105 and connected to the first annular water tank 105. To prevent the fluidizing water delivered from the first water injection pipe 109 to the first annular water tank 105 from directly entering the first rectangular water tank 106, and to mitigate the impact of the fluidizing water, the first water injection pipe 109 is perpendicular to the first rectangular water tank 106.

[0046] Considering the feed to the first flotation column 102, such as Figure 1 As shown, the first flotation column 100 also includes a first feed pipe 110 and a first feed distributor 111. The first feed distributor 111 is disposed inside the first flotation column body 102 and is connected to the lower end of the first feed pipe 110. The lower end of the first feed pipe 110 is located inside the first flotation column body 102, and the upper end of the first feed pipe 110 extends out from the upper end of the first flotation column body 102. It is worth noting that the first feed distributor 111 is located inside the first flotation column body 102, slightly towards the upper end.

[0047] like Figure 1 As shown, the first flotation column 100 also includes a clean coal spray pipe 112, which is located at the upper end of the first clean coal trough 101.

[0048] Considering the emissions from refined coal, such as Figure 1As shown, the first flotation column 100 also includes a first clean coal overflow pipe 113 and a first clean coal solenoid valve 114. The first clean coal overflow pipe 113 is connected to the first clean coal trough 101, and the first clean coal solenoid valve 114 is provided on the first clean coal overflow pipe 113 for opening and closing the first clean coal overflow pipe 113.

[0049] In order to control the emission of tailings, such as Figure 1 As shown, the first flotation column 100 also includes a T-shaped tailings pipe 115, a first tailings solenoid valve 116, and a second tailings solenoid valve 117. The upper end of the longitudinal tube of the T-shaped tailings pipe 115 is connected to the first tailings cone 103, and the lower end of the longitudinal tube of the T-shaped tailings pipe 115 is equipped with the first tailings solenoid valve 116 for controlling the opening and closing of the lower end of the longitudinal tube of the T-shaped tailings pipe 115. One end of the horizontal tube of the T-shaped tailings pipe 115 is connected to the upper end of the longitudinal tube of the T-shaped tailings pipe 115, and the other end of the horizontal tube of the T-shaped tailings pipe 115 is equipped with the second tailings solenoid valve 117 for controlling the opening and closing of the horizontal tube of the T-shaped tailings pipe 115.

[0050] like Figure 1 As shown, the first flotation column 100 also includes a first flow stabilizer 118, which is disposed inside the first flotation column body 102. Preferably, there are two first flow stabilizers 118.

[0051] Considering the formation of fluidized water, such as Figure 1 As shown, the parallel two-stage fluidized flotation device also includes a first microbubble generator 300, which is connected to the first fluid distributor 104. Specifically, the first microbubble generator 300 is connected to the first water injection pipe 109 through a pipeline.

[0052] like Figure 1 As shown, the second flotation column 200 also includes a second clean coal trough 203 and a second tail coal cone 204, which are respectively located on the upper and lower sides of the second flotation column 202.

[0053] like Figure 1 As shown, the second flotation column 200 also includes a second fluid distributor 205, which is located between the second flotation column 202 and the second tailings cone 204. That is, the second clean coal trough 203, the second flotation column 202, the second fluid distributor 205 and the second tailings cone 204 are arranged sequentially from top to bottom.

[0054] In this embodiment, the second clean coal trough 203 is located at the top of the second flotation column 202 and is used to collect clean coal. The second fluid distributor 205 is located at the bottom of the second flotation column 202 and is used to supply fluidizing water into the second flotation column 202, thereby creating a low-turbulence, high-phase-content flow field environment. The second tailings cone 204 is located at the bottom of the second fluid distributor 205 and is used to collect tailings.

[0055] like Figure 5 As shown, the second fluid distributor 205 includes a second annular water tank 206 and a plurality of second rectangular water tanks 207. The plurality of second rectangular water tanks 207 are arranged parallel to each other in the inner ring of the second annular water tank 206 and are in communication with the second annular water tank 206. Specifically, both ends of the second rectangular water tanks 207 are in communication with the second annular water tank 206. Preferably, the plurality of second rectangular water tanks 207 are arranged at equal intervals within the second annular water tank 206. The two ends of the second rectangular water tanks 207 are welded and fixed to the second annular water tank 206.

[0056] Furthermore, such as Figure 6 and Figure 7 As shown, the second rectangular water tank 207 includes a second U-shaped water tank 208 and a second fluid distribution plate 209. The second fluid distribution plate 209 is located at the opening of the second U-shaped water tank 208. The fluidized water entering the second U-shaped water tank 208 enters the second flotation column 202 through the second fluid distribution plate 209, forming a low-turbulence, high-phase-content flow field environment in the second flotation column 202.

[0057] In this embodiment, both the first fluid distributor 104 and the second fluid distributor 205 are single annular water tanks and a set of parallel fluid distribution boxes. Compared with multiple concentric annular fluid distribution structures, this structure is simple, easy to process and form, and provides uniform fluid distribution, which is beneficial for the flotation recovery of coarse particles.

[0058] Considering the need to inject fluidizing water into the second annular water tank 206, such as Figure 5 and Figure 6 As shown, the second fluid distributor 205 also includes two second water injection pipes 210, which are symmetrically located on both sides of the second annular water tank 206 and connected to the second annular water tank 206. To prevent the fluidizing water delivered from the second water injection pipes 210 to the second annular water tank 206 from directly entering the second rectangular water tank 207, and to mitigate the impact of the fluidizing water, the second water injection pipes 210 are perpendicular to the second rectangular water tank 207.

[0059] Considering the feed to the second flotation column 202, such as Figure 1 As shown, the second flotation column 200 also includes a second feed distributor 211, which is disposed inside the second flotation column 202 and connected to the lower end of the second feed pipe 201. The lower end of the second feed pipe 201 is located inside the second flotation column 202, and the upper end of the second feed pipe 201 extends out from the upper end of the second flotation column 202. It is worth noting that the second feed distributor 211 is located inside the second flotation column 202, slightly towards the upper end.

[0060] Considering the emissions from refined coal, such as Figure 1 As shown, the second flotation column 200 also includes a second clean coal overflow pipe 212 and a second clean coal solenoid valve 213. The second clean coal overflow pipe 212 is connected to the second clean coal trough 203, and the second clean coal solenoid valve 213 is installed on the second feed pipe 201 to control the opening and closing of the pipeline connecting the first clean coal trough 101 and the second flotation column 202.

[0061] Specifically, such as Figure 1 As shown, the second feed pipe 201 is a T-shaped pipe. The lower end of the longitudinal section of the second feed pipe 201 is located inside the second flotation column 202 and connected to the second feed distributor 211. The upper end of the longitudinal section of the second feed pipe 201 is located outside the second flotation column 202 and connected to the horizontal section of the second feed pipe 201. One end of the horizontal section of the second feed pipe 201 is connected to the upper end of the longitudinal section of the second feed pipe 201, and the other end of the horizontal section of the second feed pipe 201 is connected to the first clean coal trough 101. The second clean coal solenoid valve 213 is located on the horizontal section of the second feed pipe 201 and is used to control the opening and closing of the horizontal section of the second feed pipe 201.

[0062] Considering the emissions of tailings, such as Figure 1 As shown, the second flotation column 200 also includes a second tailings pipe 214, the upper end of which is connected to the second tailings cone 204. The second flotation column 200 also includes a second flow stabilizer 215, which is disposed inside the second flotation column body 202. Preferably, there are two second flow stabilizers 215.

[0063] Considering the formation of fluidized water, such as Figure 1 As shown, the parallel two-stage fluidized flotation device also includes a second microbubble generator 400, which is connected to the second fluid distributor 205. Specifically, the second microbubble generator 400 is connected to the second water injection pipe 210 through a pipeline.

[0064] In this embodiment, a large number of microbubble groups required for fluidization are introduced into the first flotation column 102 and the second flotation column 202 by the first microbubble generator 300 and the second microbubble generator 400, respectively. With the help of the first fluid distributor 104 and the second fluid distributor 205, and the first flow stabilizer 118 and the second flow stabilizer 215, a flotation flow field environment with low fluid disturbance and high microbubble content is constructed inside the first flotation column 102 and the second flotation column 202, which effectively suppresses the turbulent dissipation of the flow field and is more conducive to the fluidized flotation recovery of coarse minerals.

[0065] like Figure 1 As shown, the parallel two-stage fluidized bed flotation device also includes a slurry pump 500. The horizontal pipe of the T-shaped tailings pipe 115 is connected to the slurry pump 500 through a pipeline. The slurry pump 500 is connected to the upper end of the longitudinal pipe of the second feed pipe 201 through a pipeline.

[0066] In this implementation, by setting up a two-stage fluidized bed flotation system, the flow rate within the first microbubble generator 300 and the second microbubble generator 400 can be controlled to adjust the upward flow velocity within the first flotation column 102 and the second flotation column 202. This allows for the creation of two low-turbulence, high-phase flow field environments with different upward flow velocities within a single device. The low-velocity flow field can be used to recover low-ash clean coal from the coarse coal slime feed, ensuring the quality of the clean coal. The high-velocity flow field is used to recover high-ash tailings particles, ensuring the recovery rate and tailings ash content, effectively guaranteeing product quality.

[0067] In this embodiment, by producing three products—clean coal, middlings coal, and tailings coal—the quality requirements of clean coal products are effectively guaranteed while avoiding problems such as excessively low ash content in tailings coal, which could lead to the loss of valuable components, thus ensuring a high recovery rate of valuable components.

[0068] In this embodiment, the arrangement of the T-shaped second feed pipe 201, the first clean coal solenoid valve 114, the second clean coal solenoid valve 213, the T-shaped tailings pipe 115, the first tailings solenoid valve 116, the second tailings solenoid valve 117, and the slurry pump 500, etc., enables the formation of two separation modes in the same device: "roughing + cleaning" and "roughing + scavenging". The "roughing + cleaning" mode separates the coarse coal slime with poor coal quality, while the "roughing + scavenging" mode separates the coarse coal slime with better coal quality. This addresses the different properties of the incoming coarse coal slime and is more adaptable to the incoming coal flow with fluctuating coal quality.

[0069] Example 2

[0070] Another specific embodiment of the present invention, such as Figures 1-7 As shown, a parallel two-stage fluidized bed flotation method suitable for fluctuating feed is disclosed, employing the parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in Example 1. The steps include:

[0071] Step S1: Determine the quality of the incoming coarse coal slime. If the quality of the coarse coal slime is poor, proceed to step S2. If the quality of the coarse coal slime is good, proceed to step S3.

[0072] It should be noted that the quality of coal needs to be judged based on the properties of the feed. If the mass percentage of high-ash fine mud (particle size less than 74μm, ash content higher than 25%) in the feed is not less than 15%, and the density of coarse particles (particle size greater than 0.25mm) in the feed is 1.4-1.8 g / cm³, then the quality is considered acceptable. 3 When the mass ratio of coal gangue (i.e., coal gangue intergrowth) is not less than 30%, it is considered that the quality of the feed coal is poor; otherwise, it is considered that the quality of the feed coal is good.

[0073] Step S2: The coarse coal slime is separated using a coarse selection + fine selection separation mode.

[0074] Step S2.1: Close the second tail coal solenoid valve 117 and open the first tail coal solenoid valve 116, without turning on the slurry pump 500; close the first clean coal solenoid valve 114 and open the second clean coal solenoid valve 213, thereby setting the separation mode of the flotation device to "roughing + cleaning".

[0075] Step S2.2: A low-turbulence, high-phase-content flow field environment is formed in both the first flotation column 102 and the second flotation column 202.

[0076] Specifically, water is introduced into the first microbubble generator 300, where air is drawn in and broken into microbubbles by the Venturi tube structure, forming microbubble-rich fluidized water. The microbubble-rich fluidized water is injected into the first fluid distributor 104 through the first water injection pipe 109, enters the first annular water tank 105, then enters the first rectangular water tank 106, and enters the first flotation column 102 by the first fluid distribution plate 108, where a low-turbulence, high-phase-content flow field environment is formed.

[0077] Water with a lower flow rate (the fluid velocity inside the second flotation column 202 should be lower) is introduced into the second microbubble generator 400. Air is drawn in and broken into microbubbles by the Venturi tube structure therein, forming microbubble-rich fluidized water. The microbubble-rich fluidized water is injected into the second fluid distributor 205 through the second water injection pipe 210. The microbubble-rich fluidized water enters the second annular water tank 206, then enters the second rectangular water tank 207, and enters the second flotation column 202 through the second fluid distribution plate 209, where a low-turbulence, high-phase-content flow field environment is formed.

[0078] Step S2.3: Inject coarse coal slime into the first flotation column 102.

[0079] Specifically, after the first flotation column 102 and the second flotation column 202 are filled with fluidizing water and a low-turbulence, high-phase-content flow field environment is formed, and the upward flow velocity in the first flotation column 102 is higher than that in the second flotation column 202, coarse coal slime with coal quality deviation is injected through the first feed pipe 110 and evenly fed into the first flotation column 102 through the first feed distributor 111. The coal particles in the feed sink under the action of gravity, meet and collide with the microbubbles in the upward flow of water in the first flotation column 102, and the clean coal and coal gangue in the particles adhere to the bubbles, forming mineralized bubbles. Under the combined action of gravity and buoyancy, they float to the foam layer and move with the foam layer into the first clean coal trough 101 to become a section of clean coal. High-ash particles (mainly gangue) cannot adhere to the air bubbles and settle under gravity. After passing through the first fluid distributor 104, they sink to the first tailings cone 103 and are finally discharged through the T-shaped tailings pipe 115, becoming tailings. This step is mainly used to ensure the high ash content of the tailings.

[0080] It should be noted that the method for determining whether the first flotation column 102 and the second flotation column 202 are filled with fluidizing water is by visually observing from the top of the first flotation column 102 and the second flotation column 202. For determining the formation of a low-turbulence, high-phase-content flow field environment: firstly, low turbulence can be directly observed with the naked eye; when the water flow in the container rises relatively steadily and the overflow outlet is observed to be relatively stable without violent fluctuations, it is considered low-turbulence. High phase content is manifested in the presence of a large number of air bubbles in the overflowing fluidizing water, to the point that the fluidizing water appears white rather than normally transparent.

[0081] Step S2.4: A section of clean coal enters the second flotation column 200 for separation.

[0082] Specifically, a section of clean coal from the first clean coal bin 101 enters through the second feed pipe 201 and is then uniformly fed into the second flotation column 202 by the second feed distributor 211. The particles settle under gravity and collide with microbubbles in the rising water flow within the second flotation column 202. The clean coal in the particles adheres to the bubbles, forming mineralized bubbles. Under the combined action of gravity and buoyancy, the bubbles rise to the foam layer and move with the foam layer into the second clean coal bin 203, and are discharged as clean coal through the second clean coal overflow pipe 212.

[0083] Coal and gangue aggregates with high ash content cannot float and settle under gravity. After passing through the second fluid distributor 205, they sink to the second tailings cone 204 and are finally discharged through the second tailings pipe 214, becoming middlings. This step is mainly used to ensure the low ash content of the clean coal and improve its quality.

[0084] Step S3: The coarse coal slime is separated using a coarse separation + scavenging separation method.

[0085] Step S3.1: Open the second tailings solenoid valve 117 and close the first tailings solenoid valve 116 at the same time, and start the slurry pump 500; open the second clean coal solenoid valve 213 and close the first clean coal solenoid valve 114, thereby setting the flotation device separation mode to "roughing + scavenging".

[0086] Step S3.2: A low-turbulence, high-phase-content flow field environment is formed in both the first flotation column 102 and the second flotation column 202.

[0087] Specifically, water is introduced into the first microbubble generator 300, where air is drawn in and broken into microbubbles by the Venturi tube structure, forming microbubble-rich fluidized water. The microbubble-rich fluidized water is injected into the first fluid distributor 104 through the first water injection pipe 109, enters the first annular water tank 105, then enters the first rectangular water tank 106, and enters the first flotation column 102 by the first fluid distribution plate 108, where a low-turbulence, high-phase-content flow field environment is formed.

[0088] A higher flow rate of water is introduced into the second microbubble generator 400, where air is drawn in and broken into microbubbles through the Venturi tube structure, forming microbubble-rich fluidized water. The microbubble-rich fluidized water is injected into the second fluid distributor 205 through the second water injection pipe 210, enters the second annular water tank 206, then enters the second rectangular water tank 207, and enters the second flotation column 202 through the second fluid distribution plate 209, where a low-turbulence, high-phase-content flow field environment is formed.

[0089] Step S3.3: Inject coarse coal slime into the first flotation column 102.

[0090] Specifically, after the first flotation column 102 and the second flotation column 202 are filled with fluidizing water and form a low-turbulence, high-phase-content flow field environment, and the upward flow velocity in the first flotation column 102 is higher than that in the second flotation column 202, coarse coal slime with coal quality deviation is injected through the first feed pipe 110 and evenly fed into the first flotation column 102 through the first feed distributor 111. The coal particles in the feed sink under the action of gravity, meet and collide with the microbubbles in the upward flow of water in the first flotation column 102, and the clean coal in the particles adheres to the bubbles, forming mineralized bubbles. Under the combined action of gravity and buoyancy, the bubbles float to the foam layer and move with the foam layer into the first clean coal trough 101 and are discharged through the first clean coal overflow pipe 113 as clean coal product. High-ash particles and coal gangue intergrowth settle under gravity, passing through the first fluid distributor 104 and sinking to the first tailings cone 103, eventually entering the T-shaped tailings pipe 115 to become a section of tailings. This step is mainly used to ensure the low ash content of the clean coal and improve its quality.

[0091] Step S3.4: The tailings enter the second flotation column 200 for separation.

[0092] Specifically, a section of tailings from the T-shaped tailings pipe 115 enters the second feed pipe 201 under the action of the slurry pump 500 and is evenly fed into the second flotation column 202 by the second feed distributor 211. The particles settle under the action of gravity and meet and collide with microbubbles in the rising water flow in the second flotation column 202. The coal gangue intergrowth in the particles adheres to the bubbles, forming mineralized bubbles. Under the combined action of gravity and buoyancy, the bubbles float to the foam layer and move with the foam layer into the second clean coal trough 203 and are discharged from the second clean coal overflow pipe 212 as middlings.

[0093] Coal and gangue aggregates with high ash content cannot float and settle under gravity. After passing through the second fluid distributor 205, they sink to the second tailings cone 204 and are finally discharged through the second tailings pipe 214, becoming tailings. This step is mainly used to ensure the high ash content of the tailings.

[0094] In this embodiment, the arrangement of the T-shaped second feed pipe 201, the first clean coal solenoid valve 114, the second clean coal solenoid valve 213, the T-shaped tailings pipe 115, the first tailings solenoid valve 116, the second tailings solenoid valve 117, and the slurry pump 500, etc., enables the formation of two separation modes in the same device: "roughing + cleaning" and "roughing + scavenging". The "roughing + cleaning" mode separates the coarse coal slime with poor coal quality, while the "roughing + scavenging" mode separates the coarse coal slime with better coal quality. This addresses the different properties of the incoming coarse coal slime and is more adaptable to the incoming coal flow with fluctuating coal quality.

[0095] 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. A parallel two-stage fluidized bed flotation device suitable for fluctuating feed, characterized in that, The system includes a first flotation column (100) and a second flotation column (200), which are arranged in parallel. The first flotation column (100) includes a first clean coal bin (101), a first flotation column body (102), and a first tailings cone (103). The first clean coal bin (101) and the first tailings cone (103) are respectively located on the upper and lower sides of the first flotation column body (102). The second flotation column (200) includes a second feed pipe (201) and a second flotation... The first flotation column (202) has a second feed pipe (201) located above it. The first clean coal trough (101) and the first tailings cone (103) are both connected to the second feed pipe (201). The first flotation column (100) also includes a first clean coal overflow pipe (113) and a first clean coal solenoid valve (114). The first clean coal overflow pipe (113) is connected to the first clean coal trough (101), and the first clean coal solenoid valve (114) is located on the first clean coal overflow pipe (113) and is used for the first clean coal... The overflow pipe (113) is opened and closed; the first flotation column (100) also includes a T-shaped tailings pipe (115), a first tailings solenoid valve (116) and a second tailings solenoid valve (117). The upper end of the longitudinal pipe of the T-shaped tailings pipe (115) is connected to the first tailings cone (103), and the lower end of the longitudinal pipe of the T-shaped tailings pipe (115) is provided with the first tailings solenoid valve (116) to control the opening and closing of the lower end of the longitudinal pipe of the T-shaped tailings pipe (115); one end of the transverse pipe of the T-shaped tailings pipe (115) is connected to the upper end of the longitudinal pipe of the T-shaped tailings pipe (115). The other end of the horizontal tube of the T-shaped tail coal pipe (115) is provided with a second tail coal solenoid valve (117) for controlling the opening and closing of the horizontal tube of the T-shaped tail coal pipe (115); the second flotation column (200) also includes a second clean coal overflow pipe (212) and a second clean coal solenoid valve (213). The second clean coal overflow pipe (212) is connected to the second clean coal trough (203), and the second clean coal solenoid valve (213) is provided on the second feed pipe (201) for controlling the opening and closing of the pipeline connecting the first clean coal trough (101) and the second flotation column (202).

2. The parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in claim 1, characterized in that, The first flotation column (102) is placed on one side of the second flotation column (202), and the second flotation column (202) is lower than the first flotation column (102).

3. The parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in claim 1, characterized in that, The first flotation column (100) further includes a first fluid distributor (104), which is located between the first flotation column body (102) and the first tailings cone (103).

4. The parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in claim 1, characterized in that, The first flotation column (100) further includes a first feed pipe (110) and a first feed distributor (111). The first feed distributor (111) is located inside the first flotation column body (102) and is connected to the lower end of the first feed pipe (110).

5. The parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in claim 1, characterized in that, The first flotation column (100) also includes a clean coal spray pipe (112), which is located at the upper end of the first clean coal trough (101).

6. The parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in claim 3, characterized in that, It also includes a first microbubble generator (300) connected to the first fluid distributor (104).

7. The parallel two-stage fluidized bed flotation apparatus suitable for fluctuating feed as described in any one of claims 1-6, characterized in that, The second flotation column (200) also includes a second clean coal trough (203) and a second tail coal cone (204), which are respectively located on the upper and lower sides of the second flotation column (202).

8. The parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in claim 7, characterized in that, The second flotation column (200) also includes a second fluid distributor (205) located between the second flotation column body (202) and the second tailings cone (204).

9. The parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in claim 8, characterized in that, It also includes a second microbubble generator (400) connected to the second fluid distributor (205).

10. A parallel two-stage fluidized bed flotation method suitable for fluctuating feed, characterized in that, The coarse coal slime is separated using a parallel two-stage fluidized bed flotation device suitable for fluctuating feed as described in any one of claims 1-9.

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