Improved high-efficiency turbulent micro-bubble flotation device for feeding and discharging materials

Abstract

The application discloses an improved high-efficiency turbulent micro-bubble flotation device for feeding and discharging materials, which comprises an outer cylinder, an inner cylinder arranged in the outer cylinder, a stirring mechanism arranged in the outer cylinder, a feeding mechanism for conveying raw materials into the inner cylinder, a concentrate tank arranged at the upper portion of the outer cylinder, a countercurrent mineralization mechanism arranged in the inner cylinder and a tailing separation mechanism connected to the bottom of the inner cylinder. The sawtooth disc self-suction dispersion impeller and the false bottom structure are matched to form a local area circulation, which can enhance the elution effect of the surface of coarse particles and help the dispersion of heterogeneous fine mud, and further ensure the purity of tailings. In addition to improving the flotation efficiency, the application also greatly reduces the energy consumption. The design of the sawtooth disc self-suction dispersion impeller allows the gas to be self-sucked into, avoiding the energy consumption of the traditional air compression equipment. The sawtooth disc self-suction dispersion impeller can improve the suction force caused by the vacuum effect generated by the rotation of the impeller, and promote more air to be sucked in.

Description

Technical Field

[0001] The invention relates to the technical field of mineral separation, in particular to an improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials. Background Art

[0002] With the increasing scarcity of global mineral resources and the tightening of environmental regulations, traditional mineral processing technologies are facing unprecedented challenges. While rapid advances in mechanized mining technology have improved production efficiency, they have also brought with them the challenge of increasingly fine mineral particle size. Furthermore, the increasing content of high ash and intergrown minerals in ores has significantly increased the difficulty of sorting and recovering fine-grained minerals. Traditional flotation processes are particularly ineffective when handling ultrafine materials. Froth flotation, the most economical separation method in mineral processing, has been widely used in mineral processing plants both domestically and internationally. Its primary equipment includes mechanical flotation cells and flotation columns. While mechanical agitator flotation cells have a long history, their separation efficiency is significantly insufficient when processing ultrafine particles with a diameter of less than 45 microns. This is primarily due to mechanical entrainment, which can lead to the misrecovery of gangue mineral particles, thus affecting the concentrate grade.

[0003] As a highly efficient separation device, flotation columns have attracted widespread attention due to their simple structure, ease of control, and high flotation efficiency. They are particularly suitable for processing low-grade, finely embedded particle-size, and complex mineral resources. In recent years, the application of new flotation columns such as CPT flotation columns, Jameson flotation columns, packed flotation columns, and cyclone-static microbubble flotation columns in mineral flotation has demonstrated that they offer separation performance unmatched by conventional flotation machines when processing fine-grained, difficult-to-separate minerals. However, flotation columns also face challenges in practical application. In particular, when processing highly intertwined minerals, flotation columns often struggle to effectively improve concentrate grade and maintain high recoveries. Furthermore, shear desorption of coarse particles under high turbulence limits the separation efficiency of coarse particles, necessitating improvements in selectivity and adaptability.

[0004] In order to meet these challenges, the industry has an increasingly urgent need to develop new flotation equipment, with the goal of improving the recovery rate and sorting efficiency of fine-grained minerals while reducing energy consumption and lowering environmental impact. Against this background, two-stage flotation equipment came into being, specifically to solve the problems of low recovery rate and poor selectivity in fine-grained sorting. This technology not only optimizes the mineral sorting process and improves energy efficiency, but also enhances the overall economy and sustainability of the flotation system, bringing innovation to the mineral processing industry. However, the existing two-stage flotation machine, as described in patent CN117983421A, uses the method of collecting tailings at the bottom of the outer cylinder, which is easily affected by liquid level fluctuations and the concentrate grade. When the machine is shut down, slurry accumulates in the stirring zone of the inner cylinder, resulting in mineral deposition, which affects the normal startup of the equipment. Furthermore, the flat bottom structure of the outer cylinder combined with the anti-rotation plate can easily lead to insufficient upward power of the slurry and difficulty in foam overflow.

[0005] Therefore, it is necessary to further improve the existing technology to provide a more reliable flotation solution. Summary of the Invention

[0006] In view of the above analysis, the present invention aims to provide an improved high-efficiency turbulent microbubble flotation device with improved feeding and discharging, so as to solve the problems of high power consumption, coarse particle separation, low probability of fine particle collision and high product ash content in existing fine particle flotation equipment.

[0007] To achieve the above objectives, the present invention adopts a technical solution: to provide an improved high-efficiency turbulent microbubble flotation device with feeding and discharging, comprising: an outer cylinder, an inner cylinder disposed inside the outer cylinder, a stirring mechanism disposed inside the outer cylinder, a feeding mechanism for conveying raw materials into the inner cylinder, a concentrate tank located above the outer cylinder, a countercurrent mineralization mechanism disposed inside the inner cylinder, and a tailings separation mechanism connected to the bottom of the inner cylinder;

[0008] The countercurrent mineralization mechanism comprises a perforated plate type tangential flow impeller, a high-throughput axial conveying impeller and a sawtooth disc self-priming dispersion impeller, which are concentrically arranged on the stirring shaft of the stirring mechanism and spaced apart from top to bottom.

[0009] Preferably, the feeding mechanism includes an annular distribution pipe arranged around the middle of the outer cylinder and a plurality of feeding pipes connected to the annular distribution pipe, the ends of the feeding pipes are perpendicular to the top of the inner cylinder, and a feeding port is provided on the annular distribution pipe.

[0010] Preferably, a conical partition is sealed between the outer cylinder and the inner cylinder, and the area between the conical partition and the inner cylinder forms a downwardly concave conical guide cavity.

[0011] Preferably, a plurality of anti-rotation grooves for the slurry in the inner cylinder to pass through are arranged in an annular array on the outer wall of the upper portion of the inner cylinder between the cover plate and the conical partition plate, and the anti-rotation grooves are inclined rectangular grooves.

[0012] Preferably, a cover plate is provided on the upper portion of the inner cylinder for sealing, and a tube hole for inserting the feeding tube and a shaft hole for inserting the stirring shaft are provided on the cover plate;

[0013] The stirring mechanism includes a stirring motor arranged above the outer cylinder and a stirring shaft drivingly connected to the stirring motor;

[0014] A support plate for mounting a stirring motor is provided above the outer cylinder, and an air duct communicating with the external environment is provided on the support plate below the stirring motor;

[0015] The stirring shaft is a hollow shaft. An upper air inlet hole and a lower air inlet hole are respectively provided on the upper part and the lower part of the stirring shaft. An air inlet ring is provided on the upper air inlet hole. The air inlet ring is located in the air duct.

[0016] Preferably, the serrated disc self-priming dispersion impeller comprises an upper serrated disc, a dispersion impeller with a tubular structure, and a lower serrated disc, which are sequentially connected from top to bottom;

[0017] The dispersion impeller includes a plurality of impeller blades connected to the stirring shaft at an annular interval. The interior of the impeller blades has a hollow tube structure. The hollow tube structure forms a suction port and a discharge port at the inner and outer ends of the impeller blades, respectively. A circulation cavity is formed between two adjacent impellers. The discharge port is connected to the lower air inlet hole on the stirring shaft through the circulation cavity at a corresponding position. The bottom of the internal cavity of the stirring shaft does not pass through the lower serrated disc.

[0018] The upper serrated disc has a serrated portion at its edge and a plurality of upper disc holes extending through its middle portion; the lower serrated disc has a serrated portion at its edge and a plurality of lower disc holes extending through its middle portion; viewed vertically, the upper disc holes and the lower disc holes do not completely overlap.

[0019] The impeller blades do not completely cover or partially cover the upper disc hole or the lower disc hole, so that the upper disc hole and the lower disc hole can be connected up and down through the circulation cavity between adjacent impeller blades.

[0020] Preferably, the orifice-type tangential flow impeller comprises a plurality of trapezoidal blades annularly connected to the stirring shaft, and a plurality of through holes are formed in an array on the trapezoidal blades;

[0021] The high-throughput axial conveying impeller includes a plurality of lifting impellers annularly connected to the stirring shaft, and the lifting impeller includes an impeller connecting rod connected to the stirring shaft and an arc-shaped impeller plate connected to the end of the impeller connecting rod;

[0022] The arc-shaped impeller plate is tilted, with its lower surface concave inward and its upper surface convex outward. The connection position between the impeller connecting rod and the arc-shaped impeller plate is above the center line of the arc-shaped impeller plate.

[0023] Preferably, a false bottom is provided at the bottom of the inner cylinder and is located between the serrated disc self-priming dispersion impeller and the tailings separation mechanism. The false bottom includes a plurality of support columns connected to the bottom of the inner cylinder, a bottom plate connected above the support columns, and a slurry hole opened in the middle of the bottom plate. A gap is left between the bottom plate and the lower serrated disc, and the through hole is concentric with the stirring shaft and is located below the lower serrated disc.

[0024] Preferably, the tailings separation mechanism includes a concentrating cone disposed in communication with the bottom of the inner cylinder and below the false bottom, a tailings pipe communicating with the concentrating cone, and a tailings valve disposed on the tailings pipe.

[0025] Preferably, a diameter-reducing cover is provided above the interior of the outer cylinder, the diameter-reducing cover comprising a conical cover portion connected to the inner wall of the outer cylinder and a cylindrical cover portion connected above the conical cover portion, and a concentrate trough is formed between the diameter-reducing cover and the inner wall of the outer cylinder;

[0026] A water distribution ring and a spray water pipe connected to the water distribution ring are provided on the inner wall of the outer cylinder in an area above the concentrate tank, and a water spray port is provided on the water distribution ring.

[0027] Another aspect of the present invention provides a novel method for enhancing turbulent microbubble flotation, employing the aforementioned device for enhanced flotation of minerals. The key to this method lies in the combination of countercurrent mineralization and cyclonic flow, which significantly improves the contact conditions between the mineral and the bubbles, thereby enhancing flotation efficiency, particularly in separating fine and coarse particles.

[0028] The beneficial effects of the present invention are:

[0029] 1. In the improved high-efficiency turbulent microbubble flotation device for feeding and discharging provided by the present invention, the cooperation of the serrated disc self-priming dispersion impeller and the false bottom structure can form a localized regional circulation, which can enhance the elution effect of the coarse particle surface and help disperse heterogeneous fine mud, further ensuring the purity of the tailings;

[0030] The sawtooth disc self-priming dispersion impeller of the present invention can enhance the suction force brought about by the vacuum effect generated by the rotation of the impeller, thereby promoting the inhalation of more air; it can also promote the formation of finer microbubbles in the incoming air, thereby enhancing the mineralization effect;

[0031] 2. In addition to improving flotation efficiency, this invention also significantly reduces energy consumption. The design of the serrated disc self-priming dispersion impeller allows gas to enter naturally, avoiding the energy consumption of traditional compressed air equipment. Furthermore, the three impellers in the countercurrent mineralization mechanism (serrated disc self-priming dispersion impeller, high-throughput axial conveying impeller, and orifice-type tangential flow impeller) are arranged in an inverted cone with diameters gradually increasing from bottom to top, reducing axial resistance and thus energy input. By only inputting energy into the smaller collision reaction zone, overall energy consumption and operating costs are significantly reduced, resulting in better economic benefits.

[0032] 3. The present invention achieves high-turbulence mineralization and low-turbulence static separation of fine materials by introducing a perforated plate-type tangential flow impeller. This design greatly improves the recovery rate and selectivity of fine-particle minerals.

[0033] 4. This invention effectively shortens the migration path of mineralized bubbles through a countercurrent mineralization mechanism, and the formation of an upwelling facilitates the unpowered transport of foam. This design not only improves the processing capacity of the equipment, but also makes the flotation process more efficient.

[0034] 5. The tailings outlet of the present invention is arranged at the bottom of the inner cylinder, which is convenient for liquid level control and avoids operation problems caused by mineral accumulation when the equipment is shut down, thereby improving the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the internal structure of the improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials in Example 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the external structure of the improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials in Example 1 of the present invention;

[0037] Figure 3 Schematic diagram of the internal model structure of the improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials in Example 1 of the present invention;

[0038] Figure 4 Schematic diagram of the structure of the countercurrent mineralization mechanism in Example 1 of the present invention;

[0039] Figure 5 Schematic diagram of the model structure of the countercurrent mineralization mechanism in Example 1 of the present invention;

[0040] Figure 6 This is a partial cross-sectional structural diagram of the sawtooth disc self-priming dispersion impeller in Example 1 of the present invention;

[0041] Figure 7 This is a model diagram of the partial cross-sectional structure of the sawtooth disc self-priming dispersion impeller in Example 1 of the present invention;

[0042] Figure 8 Schematic diagram of the pulp flow state inside the improved high-efficiency turbulent microbubble flotation device for feeding and discharging in Example 1 of the present invention;

[0043] Figure 9 The yields and ash content of clean coal and tail coal of the three flotation equipment CFM, TJW and XFD in the test example of the present invention are as follows;

[0044] Figure 10 It is the recovery rate index of the three flotation equipment CFM, TJW and XFD in the test example of the present invention.

[0045] Description of reference numerals:

[0046] 1—outer cylinder; 11—conical partition; 12—conical guide cavity; 13—support plate; 14—air duct; 15—diameter-reducing cover; 151—conical cover body; 152—cylindrical cover body; 16—spray water pipe; 17—water distribution ring; 18—spray outlet;

[0047] 2—inner cylinder; 21—rotation-stop groove; 22—cover plate; 23—false bottom; 231—support column; 232—bottom plate; 233—slurry hole;

[0048] 3—stirring mechanism; 31—stirring motor; 32—stirring shaft; 33—upper air inlet; 34—lower air inlet; 35—inlet ring;

[0049] 4—feeding mechanism; 41—annular distribution pipe; 42—feeding pipe; 43—feeding port;

[0050] 5—concentrate trough; 51—concentrate outlet;

[0051] 6—countercurrent mineralization mechanism;

[0052] 61—orifice plate type tangential flow impeller; 611—trapezoidal blades; 612—through hole;

[0053] 62—high-throughput axial conveying impeller; 621—lift impeller; 622—impeller connecting rod; 623—arc-shaped impeller plate;

[0054] 63—serrated disc self-priming dispersion impeller; 631—upper serrated disc; 632—dispersion impeller; 633—lower serrated disc; 6321—impeller blade; 6322—hollow tube structure; 6323—suction port; 6324—discharge port; 6325—circulation chamber; 634—serrated portion; 635—upper disc hole; 636—lower disc hole;

[0055] 7—Tailings separation mechanism; 71—Concentration cone; 72—Tailings pipe; 73—Tailings valve; 74—Tailings outlet. DETAILED DESCRIPTION

[0056] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0057] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0058] Example 1

[0059] Reference Figure 1-8The present embodiment provides an improved high-efficiency turbulent microbubble flotation device with improved feeding and discharging, comprising: an outer cylinder 1, an inner cylinder 2 arranged inside the outer cylinder 1, a stirring mechanism 3 arranged inside the outer cylinder 1, a feeding mechanism 4 for conveying raw materials into the inner cylinder 2, a concentrate tank 5 located at the upper part of the outer cylinder 1, a countercurrent mineralization mechanism 6 arranged inside the inner cylinder 2, and a tailings separation mechanism 7 connected to the bottom of the inner cylinder 2.

[0060] The countercurrent mineralization mechanism 6 includes a perforated plate type tangential flow impeller 61, a high-throughput axial conveying impeller 62 and a sawtooth disc self-priming dispersion impeller 63, which are concentrically arranged on the stirring shaft 32 of the stirring mechanism 3 and spaced apart from top to bottom.

[0061] In this embodiment, the feeding mechanism 4 includes an annular distribution pipe 41 arranged around the middle of the outer cylinder 1 and a plurality of feeding pipes 42 (8 groups of feeding pipes 42 in this embodiment) connected to the annular distribution pipe 41. The end of the feeding pipe 42 is perpendicular to the top of the inner cylinder 2, and a feeding port 43 is opened on the annular distribution pipe 41.

[0062] Among them, vertical feeding includes the following advantages:

[0063] (1) Ability to form a stable liquid flow: Vertical feeding can ensure that the pulp enters the flotation tank in a stable and concentrated manner, which helps to form a stable liquid flow, thereby improving the efficiency and stability of the flotation process. (2) Improve mineralization efficiency: Vertical feeding helps the pulp and microbubbles to be fully mixed in the impeller blades, increasing the chance of collision between mineral particles and bubbles, thereby increasing the probability of bubble mineralization. (3) Improve sorting efficiency: Vertical feeding combined with the rotation of the impeller can reduce energy consumption because the impeller has a smaller diameter and a lower circumferential speed, thereby reducing the power consumption of the equipment.

[0064] In this embodiment, a conical partition plate 11 is sealed between the outer cylinder 1 and the inner cylinder 2 , and a downwardly concave conical guide cavity 12 is formed in the area between the conical partition plate 11 and the inner cylinder 2 .

[0065] In this embodiment, a plurality of anti-rotation grooves 21 are arranged in an annular array on the outer wall of the upper portion of the inner tube 2 between the cover plate 22 and the conical partition plate 11 for the slurry in the inner tube 2 to pass through. The anti-rotation grooves 21 are inclined rectangular grooves.

[0066] In this embodiment, the upper portion of the inner cylinder 2 is sealed with a cover plate 22, which is provided with a tube hole for inserting the feed pipe 42 and a shaft hole for inserting the stirring shaft;

[0067] The stirring mechanism 3 includes a stirring motor 31 disposed above the outer cylinder 1 and a stirring shaft 32 drivingly connected to the stirring motor 31;

[0068] A support plate 13 for mounting a stirring motor 31 is provided above the outer cylinder 1, and an air duct 14 communicating with the external environment is provided on the support plate 13 below the stirring motor 31;

[0069] The agitator shaft 32 is a hollow shaft. An upper air inlet 33 and a lower air inlet 34 are respectively formed in the upper and lower portions of the agitator shaft 32. An air inlet ring 35 is provided in communication with the upper air inlet 33 and is located within the air duct 14. When the agitator shaft 32 rotates, external air first enters the air duct 14, then passes through the air inlet ring 35 and enters the cavity within the agitator shaft 32. The air is then dispersed into the slurry within the inner barrel 2 by the serrated disc self-priming dispersion impeller 63.

[0070] In this embodiment, the sawtooth disc self-priming dispersion impeller 63 includes an upper sawtooth disc 631, a dispersion impeller 632 with a tubular structure, and a lower sawtooth disc 633, which are connected in sequence from top to bottom.

[0071] The dispersion impeller 632 includes a plurality of impeller blades 6321 (six in this embodiment) connected to the stirring shaft 32 at annular intervals. The impeller blades 6321 have a hollow tubular structure 6322 inside. The hollow tubular structure 6322 forms an inlet 6323 and an outlet 6324 at the inner and outer ends of the impeller blades 6321, respectively. A circulation cavity 6325 is formed between two adjacent impellers. The outlet 6324 communicates with the lower air inlet 34 on the stirring shaft 32 through the circulation cavity 6325 at the corresponding position. The bottom of the internal cavity of the stirring shaft 32 does not pass through the lower serrated disk 633.

[0072] The upper serrated disc 631 has a serrated portion 634 on its edge and a plurality of upper disc holes 635 extending vertically through its middle. The lower serrated disc 633 has a serrated portion 634 on its edge and a plurality of lower disc holes 636 extending vertically through its middle. When viewed vertically, the upper disc holes 635 and the lower disc holes 636 do not completely overlap.

[0073] The impeller blades 6321 do not completely cover or partially cover the upper disc hole 635 or the lower disc hole 636 , so that the upper disc hole 635 and the lower disc hole 636 can be connected to each other through the circulation cavity 6325 between adjacent impeller blades 6321 .

[0074] In this embodiment, the orifice plate tangential flow impeller 61 includes a plurality of trapezoidal blades 611 (six in this embodiment) annularly connected to the agitator shaft 32. The trapezoidal blades 611 are provided with a plurality of through holes 612 in an array. As the orifice plate tangential flow impeller 61 rotates, it scrubs the mineral particles, promoting their mineralization.

[0075] The high-throughput axial conveying impeller 62 includes several lifting impellers 621 (six in this embodiment) annularly connected to the agitator shaft 32. The lifting impellers 621 include an impeller connecting rod 622 connected to the agitator shaft 32 and a curved impeller plate 623 connected to the end of the impeller connecting rod 622. The curved impeller plate 623 is tilted, with its lower surface concave inward and its upper surface convex outward. The connection between the impeller connecting rod 622 and the curved impeller plate 623 is above the centerline of the curved impeller plate 623. When the high-throughput axial conveying impeller 62 rotates, it can lift the slurry upward, promoting the sorting process.

[0076] Among them, the diameters of the impeller blade 6321, the trapezoidal blade 611, and the lifting impeller 621 increase successively to form an inverted cone arrangement, which can reduce shaft resistance and thus reduce the energy input of the rotating shaft.

[0077] In this embodiment, a false bottom 23 is provided at the bottom of the inner tube 2, which is located between the serrated disc self-priming dispersion impeller 63 and the tailings separation mechanism 7. The false bottom 23 includes several support columns 231 connected to the bottom of the inner tube 2, a bottom plate 232 connected above the support columns 231, and a slurry hole 233 opened in the middle of the bottom plate 232. A gap is left between the bottom plate 232 and the lower serrated disc 633. The through hole 612 is concentric with the stirring shaft 32 and is located below the lower serrated disc 633.

[0078] In this embodiment, the tailings separation mechanism 7 includes a concentrating cone 71 connected to the bottom of the inner tube 2 and below the false bottom 23, a tailings pipe 72 connected to the concentrating cone 71, and a tailings valve 73 provided on the tailings pipe 72. The end of the tailings pipe 72 forms a tailings outlet 74.

[0079] In this embodiment, a variable diameter cover 15 is provided above the inner portion of the outer cylinder 1. The variable diameter cover 15 includes a conical cover portion 151 connected to the inner wall of the outer cylinder 1 and a cylindrical cover portion 152 connected above the conical cover portion 151. A concentrate trough 5 is formed between the variable diameter cover 15 and the inner wall of the outer cylinder 1. A concentrate port 51 is provided on the concentrate trough 5.

[0080] A water distribution ring 17 and a spray water pipe 16 connected to the water distribution ring 17 are provided on the inner wall of the outer cylinder 1 above the concentrate tank 5 , and a water spray port 18 is provided on the water distribution ring 17 .

[0081] The outer cylinder 1 of the device sequentially forms a foam separation zone, a static separation zone, a countercurrent mineralization zone, and a tailings separation zone from top to bottom. Specifically, the foam separation zone is formed within the concentrate trough 5, the static separation zone is formed between the conical partition 11 and the concentrate trough 5, the countercurrent mineralization zone is formed within the inner cylinder 2, and the tailings separation zone is formed within the tailings separation mechanism 7.

[0082] The overall working principle and process of the flotation device of this embodiment are as follows:

[0083] 1. The conditioned slurry is pumped into the feed port 43 via a slurry pump. The annular distribution pipe 41 evenly distributes the slurry to eight connected groups of downward-feeding feed pipes 42. At this point, the stirring motor 31 drives the stirring shaft 32 to rotate, creating a negative pressure in the middle layer (circulation chamber 6325) of the serrated disc self-priming dispersion impeller 63. This draws air into the intake ring 35 through the air duct 14, and then into the countercurrent mineralization zone within the inner barrel 2 through the upper and lower intake holes 33 and 34, respectively. The air is confined and dispersed through the air holes, and then cut into microbubbles by the serrated disc, which facilitates the collision of fine particles with air bubbles.

[0084] 2. The microbubbles are lifted by the high-throughput axial conveying impeller 62 to the middle and upper part of the countercurrent mineralization zone, and meet the slurry fed through the feed pipe 42 at the orifice plate tangential flow impeller 61. The particles are scrubbed by the orifice plate tangential flow impeller 61 and mineralized with the microbubbles; fine particles are transported to the anti-rotation groove 21 by the high-throughput axial conveying impeller 62 due to their strong water-absorbing properties and then enter the static separation zone, while coarser particles sink, pass the high-throughput axial conveying impeller 62 and enter under the serrated disc self-priming dispersion impeller 63.

[0085] 3. False bottom 23 cooperates with the serrated disc self-priming dispersion blades to form a localized circulation system, capturing and floating particles that have not been countercurrently mineralized. Tailings particles then settle into concentrating cone 71 at the bottom of the countercurrent mineralization zone. Concentrating cone 71 effectively promotes particle settling and reduces the impact of tailings discharge on the overall slurry level. After concentration, the tailings are discharged through tailings valve 73 and tailings outlet 74.

[0086] 4. The conical partition 11 (with a conical guide cavity 12 formed on the top) cooperates with the interior of the concentrate tank 5 to form a C-shaped structure (refer to Figure 8 ), after the mineralized bubbles hit the C-shaped structure, a guide is formed, which promotes the formation of a C-shaped flow direction, thereby providing upward power for the mineralized bubbles and promoting the foam to form a concentrate product outward, thereby reducing the existence of dead zones and pushing the mineralized gas flocs to rise to the foam separation zone, and finally overflowing into the concentrate tank 5, and then overflowing through the water outlet 18 to spray water for defoaming and then enter the concentrate outlet 51 for discharge.

[0087] In this embodiment, the sawtooth disc self-priming dispersion impeller 63 can play the following roles:

[0088] (1) Improving the suction force brought about by the vacuum effect generated by the rotation of the impeller, and promoting the inhalation of more air: When the sawtooth disc self-priming dispersion impeller 63 rotates at a high speed, the impeller blade 6321 with the hollow tubular structure 6322 inside can quickly and massively throw the internal air outward in the direction of rotation, forming a negative pressure area in the circulation cavity 6325, prompting the external air to be sucked in through the cavity in the stirring shaft 32 and enter the slurry; at the same time, during the rotation process, the impeller blade 6321 can also play a stirring role on the slurry, which can enhance the collision between bubbles and the slurry;

[0089] (2) Promote the formation of finer microbubbles in the incoming air, thereby enhancing the mineralization effect:

[0090] When the serrated disc self-priming dispersion impeller 63 rotates at high speed, the serrated portions 634 on the edges of the upper serrated disc 631 and the lower serrated disc 633 can provide additional shearing action, shearing the inhaled air into smaller microbubbles. The formation of a large number of microbubbles is beneficial to enhancing mineralization.

[0091] (3) Cooperate with the false bottom 23 to form a local slurry circulation and improve the mineralization rate of particles:

[0092] Reference Figure 5 、 Figure 7 、 Figure 8 Under the action of the negative pressure (circulation chamber 6325 area) generated by the impeller blades 6321 of the hollow tubular structure 6322, and the cooperation of the fine gap formed by the lower serrated disc 633 and the false bottom 23, the slurry can be sucked from the center of the false bottom 23 through the lower disc hole 636 into the circulation chamber 6325 area between the impeller blades 6321. During this process, the slurry above the upper serrated disc 631 will also be sucked into the circulation chamber 6325 area through the upper disc hole 635, and then thrown out together along the rotation direction. During the throwing process, they can collide with the generated microbubbles. The slurry and bubbles are thrown out and hit the wall of the inner tube 2. Afterwards, with the auxiliary lifting of the high-throughput axial conveying impeller 62, the mineralized particles rise, and the unmineralized particles fall along the wall to the lower edge of the false bottom 23. This process is repeated, and the tailings particles are accumulated and discharged at the edge of the concentration cone 71, while the mineralizable particles continue to be sucked into circulation from the center of the false bottom 23.

[0093] It is important to note that the number of trapezoidal blades 611 of the orifice-type tangential flow impeller 61 can be adjusted to control the shearing effect on the slurry, depending on the feed properties and production site requirements. When the mineral particles are complex and contain a high amount of fine mud (difficult to flotate), the number of trapezoidal blades 611 can be increased to enhance the scrubbing effect. When the mineral particles are more uniform and contain less fine mud (easy to flotate), the number of trapezoidal blades 611 can be reduced to increase the slurry throughput, thereby increasing the equipment's processing capacity. Furthermore, the opening of the tailings valve 73 can be adjusted to control the foam height, thereby adjusting the quality and yield of the concentrate.

[0094] Test Case

[0095] To further illustrate the present invention, flotation experiments were conducted using the improved high-efficiency turbulent microbubble flotation device (with a capacity of 3 L, denoted as CFM) with feed and discharge according to Example 1. A conventional laboratory flotation machine (XFD-3L, denoted as XFD) and a turbulent static microbubble flotation machine (denoted as TJW) having the same structure as Example 1 of CN117983421A were used for comparison. The same flotation process parameters were used and the raw coal from the Wobei Coal Preparation Plant was used as the flotation feed.

[0096] The flotation process parameters are as follows: the collector and frother are original diesel and No. 2 oil, respectively, with dosages of 500g / t and 100g / t; the flotation feed concentration is maintained at 100g / L, and the flotation time is 3min.

[0097] The particle size composition of flotation feed is shown in Table 1 below:

[0098] Table 1 Flotation feed particle size composition

[0099]

[0100] Particle size composition analysis: The predominant flotation feed size is -0.045mm, accounting for 48.33% of the total sample yield and 36.42% ash. The high fines content is prone to fine mud capping and entrainment, hindering conventional flotation separation. Sludge content and ash content are unevenly distributed across the particle sizes, with the ash content increasing with decreasing particle size, resulting in a high overall ash content. The +0.25mm particle size contains less sludge, with an ash content of 9.14%. However, this low-ash sludge easily desorbs during flotation separation, coarsening into the flotation tailings and preventing effective recovery, resulting in a low tailings ash content.

[0101] The yield and ash content of clean coal and tail coal of three flotation equipments CFM, TJW and XFD are as follows: Figure 10 As shown in the figure, CFM clean coal and CFM tail respectively represent the clean coal and tail coal obtained by CFM flotation, TJW clean coal and TJW tail respectively represent the clean coal and tail coal obtained by TJW flotation, XFD clean coal and XFD tail respectively represent the clean coal and tail coal obtained by XFD flotation. The flotation recovery index results of the three flotation equipment are shown in Figure 1. Figure 10 From the flotation results, it can be seen that CFM has the best effect and the highest tailing ash content. In addition, CFM has faster flotation kinetics, which is conducive to reducing the size of the equipment.

[0102] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. An improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials, characterized in that: include: An outer cylinder, an inner cylinder disposed inside the outer cylinder, a stirring mechanism disposed inside the outer cylinder, a feeding mechanism for conveying raw materials into the inner cylinder, a concentrate trough located on the upper portion of the outer cylinder, a countercurrent mineralization mechanism disposed inside the inner cylinder, and a tailings separation mechanism connected to the bottom of the inner cylinder; The countercurrent mineralization mechanism includes a perforated plate type tangential flow impeller, a high-throughput axial conveying impeller and a sawtooth disc self-priming dispersion impeller, which are concentrically arranged on the stirring shaft of the stirring mechanism and spaced from top to bottom. The sawtooth disc self-priming dispersion impeller comprises an upper sawtooth disc, a dispersion impeller with a tubular structure and a lower sawtooth disc, which are connected in sequence from top to bottom; The dispersion impeller includes a plurality of impeller blades connected to the stirring shaft at an annular interval. The interior of the impeller blades has a hollow tube structure. The hollow tube structure forms a suction port and a discharge port at the inner and outer ends of the impeller blades, respectively. A circulation cavity is formed between two adjacent impellers. The discharge port is connected to the lower air inlet hole on the stirring shaft through the circulation cavity at a corresponding position. The bottom of the internal cavity of the stirring shaft does not pass through the lower serrated disc. The upper serrated disc has a serrated portion at its edge and a plurality of upper disc holes extending through its middle portion; the lower serrated disc has a serrated portion at its edge and a plurality of lower disc holes extending through its middle portion; viewed vertically, the upper disc holes and the lower disc holes do not completely overlap. The impeller blades do not completely cover or partially cover the upper disc hole or the lower disc hole, so that the upper disc hole and the lower disc hole can be connected up and down through the circulation cavity between adjacent impeller blades.

2. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 1 is characterized in that: The feeding mechanism includes an annular distribution pipe arranged around the middle of the outer cylinder and a plurality of feeding pipes connected to the annular distribution pipe. The ends of the feeding pipes are perpendicular to the top of the inner cylinder. The annular distribution pipe is provided with a feeding port.

3. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 2 is characterized in that: A conical partition is sealed between the outer cylinder and the inner cylinder, and a downwardly concave conical guide cavity is formed in the area between the conical partition and the inner cylinder.

4. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 3 is characterized in that: A plurality of anti-rotation grooves for the slurry in the inner cylinder to pass through are arranged in an annular row on the outer wall of the upper part of the inner cylinder between the cover plate and the conical partition plate. The anti-rotation grooves are inclined rectangular grooves.

5. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 4 is characterized in that: The upper part of the inner cylinder is sealed with a cover plate, and the cover plate is provided with a tube hole for inserting the feeding tube and a shaft hole for inserting the stirring shaft; The stirring mechanism includes a stirring motor arranged above the outer cylinder and a stirring shaft drivingly connected to the stirring motor; A support plate for mounting a stirring motor is provided above the outer cylinder, and an air duct communicating with the external environment is provided on the support plate below the stirring motor; The stirring shaft is a hollow shaft. An upper air inlet hole and a lower air inlet hole are respectively provided on the upper part and the lower part of the stirring shaft. An air inlet ring is provided on the upper air inlet hole. The air inlet ring is located in the air duct.

6. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 1 is characterized in that: The orifice plate type tangential flow impeller includes a plurality of trapezoidal blades annularly connected to the stirring shaft, and a plurality of through holes are formed in an array on the trapezoidal blades; The high-throughput axial conveying impeller includes a plurality of lifting impellers annularly connected to the stirring shaft, and the lifting impeller includes an impeller connecting rod connected to the stirring shaft and an arc-shaped impeller plate connected to the end of the impeller connecting rod; The arc-shaped impeller plate is tilted, with its lower surface concave inward and its upper surface convex outward. The connection position between the impeller connecting rod and the arc-shaped impeller plate is above the center line of the arc-shaped impeller plate.

7. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 6 is characterized in that: A false bottom is provided at the bottom of the inner cylinder and is located between the serrated disc self-priming dispersion impeller and the tailings separation mechanism. The false bottom includes a plurality of support columns connected to the bottom of the inner cylinder, a bottom plate connected above the support columns, and a slurry hole opened in the middle of the bottom plate. A gap is left between the bottom plate and the lower serrated disc. The through hole is concentric with the stirring shaft and is located below the lower serrated disc.

8. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 7, characterized in that: The tailings separation mechanism includes a concentrating cone arranged in communication with the bottom of the inner cylinder and below the false bottom, a tailings pipe communicating with the concentrating cone, and a tailings valve arranged on the tailings pipe.

9. The improved high-efficiency turbulent microbubble flotation device for feeding and discharging materials according to claim 1, characterized in that: A variable diameter cover is provided above the inner portion of the outer cylinder, the variable diameter cover comprising a conical cover portion connected to the inner wall of the outer cylinder and a cylindrical cover portion connected above the conical cover portion, and a concentrate trough is formed between the variable diameter cover and the inner wall of the outer cylinder; A water distribution ring and a spray water pipe connected to the water distribution ring are provided on the inner wall of the outer cylinder in an area above the concentrate tank, and a water spray port is provided on the water distribution ring.

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