Fluidized bed flotation device and method for coarse mineral separation recovery

Abstract

The present application relates to a kind of fluidized bed flotation device and method for coarse-grained mineral separation recovery, belong to mineral processing and resource recovery technical field, solve the problem that the existing flotation equipment fluidized bed water distribution plate is easy to block hole in prior art, large water consumption in separation process.The present application includes flotation cylinder and filling medium, the flotation cylinder includes flotation cylinder and conical baffle, the conical baffle is located at the inside lower end of the flotation cylinder, the filling medium is located on the conical baffle, the filling medium is provided with multiple layers in the flotation cylinder, the particle diameter of the filling medium increases from bottom to top layer by layer.The present application does not set water distribution plate in the flotation cylinder, i.e.filling medium replaces water distribution plate, multiple multi-scale filling medium replaces water distribution plate to carry out dynamic regulation and control to fluid distribution, the water distribution of the present application is uniform and stable, and the water consumption of separation is low.

Description

Technical Field

[0001] This invention relates to the field of mineral processing and resource recovery technology, and in particular to a fluidized bed flotation device and method for the separation and recovery of coarse minerals. Background Technology

[0002] Against the backdrop of increasingly fierce global resource competition, the efficient development and utilization of coal and mineral resources are crucial for ensuring national energy security and promoting the prosperity of emerging industries. However, facing challenges such as declining ore quality, rising mining costs, and increasingly complex processes, traditional flotation technologies are no longer sufficient to meet modern mineral processing needs. In particular, with the advancement of dual-carbon goals, energy conservation and emission reduction in mineral processing plants have become urgent tasks. Coarse-grained (coal with a diameter of 0.5 mm or more, and other ores with a diameter of 0.1 mm or more) pre-selection and waste disposal technology, with its significant potential for energy reduction and tailings resource utilization, is gradually becoming a research hotspot in the industry. Compared with traditional methods that rely on photoelectric separation and gravity separation to process large ore blocks, the emergence of dense-phase fluidized bed flotation technology has achieved efficient separation of millimeter-sized materials, opening up new avenues for deep pre-selection and waste disposal of low-grade mineral resources.

[0003] Fluidized bed flotation is a composite force field separation technology based on gravity-buoyancy coupling. Mineral particles to be separated form a fluidized bed under the action of rising water flow, and according to Archimedes' principle, undergo disturbance settling motion based on density to complete the separation process. Introduced air bubbles adhere to the surface of hydrophobic particles, increasing the density difference between them and gangue particles, thus improving separation accuracy. However, due to the complexity of the process, the development of existing fluidized bed flotation equipment has been relatively slow, greatly hindering the application and promotion of fluidized bed flotation technology. The water distribution plate is the core of the fluidized bed flotation equipment, used to disperse the fluid to form the fluidized bed. However, in actual separation processes, the openings on the surface of the water distribution plate are easily blocked by particle settling, deteriorating the fluid dispersion effect and causing problems such as bed mixing and separation density fluctuations. Furthermore, existing fluidized bed separation equipment often uses clean water as the fluidizing water, resulting in high water consumption during the separation process. This not only exacerbates the working pressure of subsequent coal slurry water treatment but also limits the technological upgrading of mineral processing plants and their use in water-scarce areas. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a fluidized bed flotation device and method for the separation and recovery of coarse minerals, in order to solve the problems of easy clogging of the fluidized bed water distribution plate and high water consumption in the separation process of existing flotation equipment.

[0005] On one hand, the present invention provides a fluidized bed flotation device for the separation and recovery of coarse minerals, comprising a flotation cylinder and a packing medium. The flotation cylinder includes a flotation tube and a conical baffle. The conical baffle is disposed at the lower end of the interior of the flotation tube, and the packing medium is disposed on the conical baffle. The packing medium is provided in multiple layers inside the flotation tube, and the particle diameter of the packing medium increases layer by layer from top to bottom.

[0006] Furthermore, the flotation cylinder also includes an overflow weir and a tailings cone, with the overflow weir and the tailings cone respectively located at the upper and lower ends of the flotation cylinder.

[0007] Furthermore, the overflow weir is provided with a concentrate outlet, and the bottom of the tailings cone is provided with an emergency discharge pipe and a tailings pipe.

[0008] Furthermore, the accident discharge pipe is equipped with a first solenoid valve for controlling the on / off state of the accident discharge pipe, and the tailings pipe is equipped with a second solenoid valve for controlling the on / off state of the tailings pipe.

[0009] Furthermore, the flotation cylinder also includes multiple pressure sensors.

[0010] Furthermore, multiple pressure sensors are arranged at equal intervals from top to bottom on the flotation cylinder.

[0011] Furthermore, the conical baffle is concentrically arranged with the flotation cylinder, and the diameter of the conical baffle is 7 / 10 to 9 / 10 of the inner diameter of the flotation cylinder.

[0012] Furthermore, the flotation cylinder is provided with a filling port for filling the filling medium.

[0013] Furthermore, the cone angle of the conical baffle is 5°-20°, and the cone angle of the tailings cone is 10°-30°.

[0014] On the other hand, the present invention provides a flotation method that uses the above-mentioned fluidized bed flotation device to separate and recover coarse-grained minerals.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0016] (1) In this invention, the filling medium is placed inside the flotation cylinder. The volume of the filling medium inside the flotation cylinder increases in layers from top to bottom, and at least two different materials are used for the filling medium. No water distribution plate is set in the flotation cylinder, that is, the filling medium replaces the water distribution plate. The use of multi-dimensional and multi-scale filling medium to replace the water distribution plate dynamically controls the fluid distribution, which enhances the stability of the fluidized separation environment and helps to achieve high-precision recovery of coarse minerals. The filling medium disperses the fluid and assists in fluidization, effectively avoiding the clogging problem of the water distribution plate caused by the sedimentation of mineral particles, and enhancing the reliability and durability of the equipment. Compared with the traditional water distribution plate structure, the pores formed between the high-density coarse-grained filling medium help to further disperse the bubbles, slow down the bubble rise rate, increase the opportunity for particles to contact bubbles, and facilitate the adhesion of bubbles to the surface of hydrophobic particles, enhance the density difference between them and hydrophilic gangue, and improve the separation effect. The low-density fine-grained filling medium can respond to changes in fluid velocity and dynamically adjust its own position to eliminate the negative impact of uneven radial velocity distribution, ensuring the balance and stability of the flow velocity of the entire column cross section.

[0017] (2) The flotation cylinder of this invention has a bottom layer of high-density, large-particle packing medium, a middle layer of medium-density, medium-particle packing medium, and an uppermost layer of low-density, fine-particle packing medium. The high-density coarse particles at the bottom are generally not fully fluidized, but the pores they form help to further disperse bubbles, slow their rise, increase the chance of contact between particles and bubbles, and facilitate the adhesion of bubbles to the surface of hydrophobic particles, thereby enhancing the density difference between them and the hydrophilic gangue and improving the separation effect. The low-density fine particles at the top are in a critical fluidized state, capable of responding to changes in fluid velocity and dynamically adjusting their position, eliminating the negative impact of uneven radial velocity distribution, and ensuring the balance and stability of the flow velocity across the entire column cross-section. The intermediate-sized particles of the two densities form a transition from bottom to top. This gradual transition helps improve the stability of the entire system and avoids a decrease in separation efficiency due to abrupt changes in fluidization state. This arrangement fully utilizes the natural stratification effect of the particles, improving separation efficiency and the stability of the fluidized bed.

[0018] (3) In this invention, the filling medium is initialized to equilibrium position by adding clean water to the mixing tank, and the flotation cylinder is filled with fluidizing medium. After the pressure signal in the system stabilizes, the original slurry is used as the fluidizing medium for formal separation. Using the original slurry instead of clean water as the fluidizing medium significantly reduces the water consumption in the separation process, simplifies the subsequent coal slurry water treatment pressure, and generates cavitation effect through the Venturi tube principle to form micro-nano-scale bubbles. The rough cracks on the surface of the particles in the slurry provide a large number of cavitation sites for bubble formation, thereby significantly improving cavitation efficiency. Subsequently, the slurry carrying the bubbles enters the fluidized bed and is co-fluidized with the filling medium. During the fluidization process, the hydrophobic particles and bubbles complete the co-current mineralization, which is prolonged. Finally, the separation of useful minerals and gangue particles is achieved based on the difference in particle density.

[0019] 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

[0020] 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.

[0021] Figure 1 This is a schematic diagram of the fluidized bed flotation device in specific embodiment 1;

[0022] Figure 2 This is a schematic diagram of the flotation cylinder of the fluidized bed flotation device in specific embodiment 2.

[0023] Figure label:

[0024] 100-Flotation cylinder; 101-Flotation cylinder; 102-Filling port; 103-Overflow weir; 104-Concentrate inlet; 105-Tailing cone; 106-Emergency discharge pipe; 107-Tailing pipe; 108-First solenoid valve; 109-Second solenoid valve; 110-Conical baffle; 111-Pressure sensor; 112-Agitator assembly; 113-Drive motor; 114-Agitator shaft; 115-Agitator impeller; 116-Isolation screen; 200-Filling medium; 300-Water replenishment mixing tank; 400-Feed mixing tank; 500-Conveying pipeline; 501-First conveying pipe; 502-Second conveying pipe; 503-Slurry pump; 504-Third solenoid valve; 505-Fourth solenoid valve; 506-Third conveying pipe; 507-Bubble generator. Detailed Implementation

[0025] 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.

[0026] Example 1

[0027] A specific embodiment of the present invention, such as Figure 1As shown, a fluidized bed flotation device for the separation and recovery of coarse minerals is disclosed, including a flotation cylinder 100 and a packing medium 200. The packing medium 200 is disposed in the inner cavity of the flotation cylinder 100. The volume of the packing medium 200 in the flotation cylinder 100 increases in layers from top to bottom. No water distribution plate is provided in the flotation cylinder 100, that is, the packing medium 200 replaces the water distribution plate.

[0028] Compared with existing technologies, the fluidized bed flotation device provided in this embodiment uses a multi-element, multi-scale filling medium 200 to replace the water distribution plate for dynamic control of fluid distribution, which enhances the stability of the fluidized separation environment and helps to achieve high-precision recovery of coarse minerals. The filling medium 200 disperses the fluid and assists in fluidization, effectively avoiding the clogging problem caused by mineral particle settling on the water distribution plate, thus enhancing the reliability and durability of the equipment. Compared with the traditional water distribution plate structure, the pores formed between the high-density coarse-grained filling medium 200 help to further disperse bubbles, slow down the bubble rise rate, increase the opportunity for particles to contact bubbles, and facilitate the adhesion of bubbles to the surface of hydrophobic particles, enhancing the density difference between them and hydrophilic gangue, and improving the separation effect. The low-density fine-grained filling medium 200 can respond to changes in fluid velocity and dynamically adjust its own position, eliminating the negative impact of uneven radial velocity distribution and ensuring the balance and stability of the flow velocity across the entire column cross-section.

[0029] like Figure 1 As shown, the flotation cylinder 100 includes a flotation cylinder 101, preferably a cylindrical cylinder. A filling medium 200 is disposed within the flotation cylinder 101. To add the filling medium 200 into the flotation cylinder 101, a filling port 102 is provided on the flotation cylinder 101. At least one filling port 102 is provided, preferably multiple ports, which are arranged along the height of the flotation cylinder 101.

[0030] When only one filling port 102 is provided, the filling port 102 should be located above the top of the flotation cylinder 101, above the filling medium 200, to avoid the filling port 102 being too low, which would prevent the filling medium 200 at higher positions from being filled into the flotation cylinder 101. When multiple filling ports 102 are provided, preferably, the height of the lower filling port 102 is higher than the height of the filling medium 200 with the lowest particle size, and so on, so as to facilitate the filling of filling media 200 with different particle sizes.

[0031] It is worth noting that since the filling port 102 is located on the flotation cylinder 101, and there is slurry inside the flotation cylinder 101, a sealing cover should be provided at the filling port 102 to prevent liquid from flowing out from the filling port 102. When it is necessary to fill the filling medium 200, simply open the sealing cover and close it after filling the filling medium 200.

[0032] Considering the collection of concentrates, such as Figure 1As shown, the flotation cylinder 100 also includes an overflow weir 103, which is located at the top of the flotation cylinder 101. The overflow weir 103 is provided with a concentrate outlet 104. After the minerals are flotated, the concentrate enters the overflow weir 103 at the top of the flotation cylinder 101 and is finally discharged from the concentrate outlet 104.

[0033] To facilitate the collection and discharge of tailings, such as Figure 1 As shown, the flotation cylinder 100 also includes a tailings cone 105, which is located at the bottom of the flotation cylinder 101. Preferably, the tailings cone 105 has an inverted conical structure, and the cone angle of the tailings cone 105 is 10°-30°. Preferably, the cone angle of the tailings cone 105 is 15°.

[0034] Furthermore, such as Figure 1 As shown, the bottom of the tailings cone 105 is provided with an emergency discharge pipe 106 and a tailings pipe 107. The emergency discharge pipe 106 is located at the bottom of the tailings cone 105 and communicates with the inner cavity of the tailings cone 105. Preferably, the emergency discharge pipe 106 and the tailings cone 105 are arranged concentrically. The tailings pipe 107 is located on one side of the emergency discharge pipe 106 and communicates with the inner cavity of the tailings cone 105. Preferably, the tailings pipe 107 is located close to the emergency discharge pipe 106. The tailings formed in the flotation cylinder 101 accumulate in the tailings cone 105. When the tailings pipe 107 is opened, the tailings are discharged from the tailings pipe 107. When an accident occurs in the flotation cylinder 100, the emergency discharge pipe 106 can be opened to discharge the minerals in the flotation cylinder 101 from the emergency discharge pipe 106.

[0035] In order to control the opening and closing of the accident discharge pipe 106 and tailings pipe 107, such as Figure 1 As shown, the flotation cylinder 100 also includes a first solenoid valve 108 and a second solenoid valve 109. The first solenoid valve 108 is located on the emergency discharge pipe 106, and the second solenoid valve 109 is located on the tailings pipe 107. The first solenoid valve 108 and the second solenoid valve 109 control the opening and closing of the emergency discharge pipe 106 and the tailings pipe 107, respectively.

[0036] In order to accommodate the filling medium 200 inside the flotation cylinder 101, such as Figure 1 As shown, the flotation cylinder 100 also includes a conical baffle 110, which is located at the lower end of the interior of the flotation cylinder 101, above the tailings cone 105. The conical baffle 110 bulges upward in the middle and downward at the edges, allowing tailings falling on the conical baffle 110 to slide from the middle to the edges, and finally fall into the tailings cone 105 through the gap between the conical baffle 110 and the inner wall of the flotation cylinder 101. The cone angle of the conical baffle 110 is generally 5°-20°, preferably 5°.

[0037] The diameter of the conical baffle 110 is 7 / 10 to 9 / 10 of the inner diameter of the flotation cylinder 101. Preferably, the diameter of the conical baffle 110 is 4 / 5 of the inner diameter of the flotation cylinder 101. In this embodiment, a gap is provided between the edge of the conical baffle 110 and the inner wall of the flotation cylinder 101, and this gap is large enough to allow flotation tailings to pass through, so that the tailings fall into the tailings cone 105. Furthermore, the diameter of the bottom packing medium 200 is larger than this gap, preventing the packing medium 200 from falling out.

[0038] To monitor the pressure distribution within the flotation cylinder 101 during the separation process in order to determine whether ore discharge or equipment parameter adjustments are necessary, such as... Figure 1 As shown, the flotation cylinder 100 also includes pressure sensors 111. Multiple pressure sensors 111 are installed at equal intervals from top to bottom on the flotation cylinder 101. The number of pressure sensors 111 is generally 3-8, preferably 4. It is worth noting that a pressure sensor 111 is also installed on the emergency discharge pipe 106.

[0039] In this embodiment, by setting multiple pressure sensors 111 on the flotation cylinder 101 and the emergency discharge pipe 106 connected to the flotation cylinder 101, the pressure distribution inside the flotation cylinder 101 during the mineral separation process can be monitored to determine whether it is necessary to discharge ore or adjust equipment parameters.

[0040] It should be noted that in the fluidized bed separation process, the rising water velocity (i.e., fluidized water velocity) is set according to the final settling velocity of the mineral particles to be separated. Intermediate-density particles with the same final settling velocity as the rising water velocity are suspended within the flotation cylinder 101, forming a fluidized bed. Low-density particles with a final settling velocity lower than the rising water velocity float as concentrate and are discharged from the flotation cylinder 101 via the overflow weir 103. High-density particles with a final settling velocity greater than the rising water velocity sink as tailings and are discharged through the tailings cone 105. Bed stability control is the core of fluidized bed flotation during the separation process. Bed stability is typically characterized by bed pressure, which is positively correlated with bed thickness (i.e., the degree of material accumulation). To improve monitoring accuracy, pressure sensors 111 are installed at equal intervals from top to bottom within the flotation cylinder 101. During the fluidized bed separation process, bed stability is controlled by monitoring the pressure distribution within the bed. When the pressure detected by pressure sensor 111 is higher than the preset threshold, it indicates that there is too much tailings accumulation, and the discharge valve needs to be opened to discharge the tailings (i.e., the tailings pipe 107 is opened through the second solenoid valve 109 for discharge). When the pressure is lower than the preset threshold, it indicates that the tailings discharge is too fast, and the valve needs to be closed to stop the discharge (i.e., the tailings pipe 107 is closed through the second solenoid valve 109) to avoid bed fluctuations. In addition, the separation effect and bed stability can be optimized by adjusting equipment parameters such as water flow rate and feed rate.

[0041] The filling medium 200 is usually spherical particles, and its type can be flexibly adjusted according to the actual minerals being sorted and the sorting density. It is generally resin (density about 1.2 g / cm³). 3 ), quartz (density approximately 2.5 g / cm³) 3 Stainless steel (density approximately 7.8 g / cm³) 3 ), copper (density approximately 8.96 g / cm³) 3 The filling medium 200 is preferably composed of a multi-component fluidization system consisting of resin and quartz. The size (diameter) of the filling medium 200 is generally between 1-10 mm, with 3, 5, and 8 mm being preferred, forming a multi-gradient particle group for synergistic control. It should be noted that the filling medium 200 should use at least two different density particle types.

[0042] In this embodiment, the bottom layer of the flotation cylinder 101 is filled with a high-density, large-particle packing medium 200, the middle layer with medium-sized particles 200, and the top layer with low-density, fine-particle packing medium 200. The high-density coarse particles at the bottom are generally not fully fluidized, but the pores they form help to further disperse bubbles, slow their rise rate, and increase the opportunity for particles to contact bubbles. This facilitates bubble adhesion to the surface of hydrophobic particles, thereby enhancing the density difference between them and the hydrophilic gangue, improving the separation effect. The low-density fine particles at the top are in a critical fluidized state, capable of responding to changes in fluid velocity and dynamically adjusting their position to eliminate the negative impact of uneven radial velocity distribution, ensuring the balance and stability of the flow velocity across the entire cylinder cross-section. The transition between the two densities of intermediate-sized particles from bottom to top is beneficial for improving the stability of the entire system and avoiding a decrease in separation efficiency due to abrupt changes in fluidization state. This arrangement fully utilizes the natural stratification effect of the particles, improving separation efficiency and the stability of the fluidized bed.

[0043] like Figure 1 As shown, the fluidized bed flotation device also includes a makeup water mixing tank 300, a feed mixing tank 400, and a conveying pipeline 500. The makeup water mixing tank 300 and the feed mixing tank 400 are connected to the flotation cylinder 101 via the conveying pipeline 500. The conveying pipeline 500 includes a first conveying pipe 501, a second conveying pipe 502, and a slurry pump 503. One end of the first conveying pipe 501 is connected to the makeup water mixing tank 300, and the other end is connected to the inlet of the slurry pump 503. One end of the second conveying pipe 502 is connected to the feed mixing tank 400, and the other end is connected to the inlet of the slurry pump 503. It should be noted that the first conveying pipe 501 and the second conveying pipe 502 can be replaced by a T-junction pipe, with the three ports of the T-junction pipe connected to the makeup water mixing tank 300, the feed mixing tank 400, and the slurry pump 503.

[0044] In order to control the on / off state of the first delivery pipe 501 and the second delivery pipe 502, such as Figure 1As shown, the delivery pipeline 500 also includes a third solenoid valve 504 and a fourth solenoid valve 505. The third solenoid valve 504 is located on the first delivery pipeline 501, and the fourth solenoid valve 505 is located on the second delivery pipeline 502.

[0045] like Figure 1 As shown, the conveying pipeline 500 also includes a third conveying pipe 506 and a bubble generator 507. One end of the third conveying pipe 506 is connected to the outlet of the slurry pump 503, and the other end passes through the flotation cylinder 101 and is connected to the conical baffle 110. A through hole is provided in the center of the conical baffle 110, and one end of the third conveying pipe 506 is connected to the through hole of the conical baffle 110.

[0046] In this embodiment, the filling medium 200 is initialized to its equilibrium position by adding clean water to the mixing tank 300, and the flotation cylinder 101 is filled with fluidizing medium. After the pressure signal in the system stabilizes, the original mineral slurry is used as the fluidizing medium for formal separation. Using the original mineral slurry instead of clean water as the fluidizing medium significantly reduces the water consumption in the separation process, simplifies the subsequent coal slime water treatment pressure, and generates cavitation effect through the Venturi tube principle, forming micro-nano-scale bubbles. The rough cracks on the particle surface in the slurry provide a large number of cavitation sites for bubble formation, thereby significantly improving cavitation efficiency. Subsequently, the slurry carrying bubbles enters the fluidized bed and is co-fluidized with the filling medium 200. During the fluidization process, hydrophobic particles and bubbles complete co-current mineralization, which is prolonged. Finally, the separation of useful minerals and gangue particles is achieved based on the difference in particle density.

[0047] Example 2

[0048] Another specific embodiment of the present invention, such as Figure 2 As shown, a fluidized bed flotation device for the separation and recovery of coarse minerals is disclosed. The difference from Embodiment 1 is that the flotation cylinder 100 further includes a stirring assembly 112. The stirring assembly 112 includes a drive motor 113, a stirring shaft 114, a stirring impeller 115, and a partition screen 116. The partition screen 116 is located inside the flotation cylinder 101, and the filling medium 200 is disposed within the partition screen 116. A groove is provided on the side wall of the partition screen 116 at the contact point with the pressure sensor 111 to prevent collision between the filling medium 200 and the pressure sensor 111 during the rotation of the stirring impeller 115. The stirring impeller 115 is mounted on the stirring shaft 114, with the lower end of the stirring shaft 114 located within the partition screen 116, and the upper end extending above the overflow weir 103 and connected to the drive motor 113. The blades of the stirring impeller 115 have a right-angled trapezoidal frame structure. It should be noted that the mesh openings on the partition screen 116 allow mineral particles to pass through. Since the filling medium 200 needs to be filled into the isolation net cylinder 116, an opening is provided at the position corresponding to the filling port 102, and the opening can be closed by a perforated mesh door.

[0049] In this embodiment, the driving motor 113 drives the stirring impeller 115 to rotate, enabling the filling medium 200 to achieve low-speed stable rotation (speed range of 10-20 rad / min) inside the isolation mesh cylinder 116. This low-speed rotation ensures the uniform distribution of the filling medium 200, thereby effectively avoiding the 'dead zone' phenomenon in the sorting process caused by uneven accumulation of the filling medium 200, that is, the area where mineral particles and bubbles cannot effectively contact each other due to inactive fluid flow; at the same time, this also prevents the flow field 'short circuit' phenomenon, that is, the material is carried out of the system prematurely without being fully sorted.

[0050] Furthermore, the low-speed rotation of the isolation mesh cylinder 116 also plays a positive auxiliary role, promoting the interaction between mineral particles and bubbles. Specifically, this rotation increases the chances of collisions between mineral particles and bubbles, increasing the probability of mineral particles adhering to the bubbles, thereby accelerating the process of mineral particles rising with the bubbles. Faster buoyancy means that mineral particles can be separated from the suspension more quickly, which not only shortens the overall sorting process time but also significantly improves the mineral recovery rate.

[0051] In summary, this embodiment not only optimizes the system's operating conditions and reduces unnecessary energy consumption, but also improves sorting efficiency, enabling more effective utilization of mineral resources, thus bringing significant advantages in both technology and economy.

[0052] Example 3

[0053] Another specific embodiment of the present invention discloses a fluidized bed flotation method for separating and recovering coarse-grained minerals, using the fluidized bed flotation apparatus of Embodiment 1 or Embodiment 2, comprising the following steps:

[0054] Step 1: Close the emergency discharge pipe 106 and tailings pipe 107, and inject filling medium 200 into the flotation cylinder 101.

[0055] Specifically, the emergency discharge pipe 106 and tailings pipe 107 are closed by the first solenoid valve 108 and the second solenoid valve 109, respectively, to prevent accidental leakage of the mineral particles to be sorted. The filling medium 200 is filled through the filling port 102 or the filling port 102 and the isolation mesh cylinder 116.

[0056] The filling medium 200 is added sequentially, following the principle of "high density first, then low density; coarse particles first, then fine particles." After completion, the filling port 102 or the opening of the filling port 102 and the isolation mesh cylinder 116 is closed. During the fluidized bed separation process, two densities of filling medium 200 particles are used to assist fluidization, with each density consisting of large, medium, and small particles. The filling principle follows the principle of "high density first, then low density; coarse particles first, then fine particles." High-density coarse particles are located at the bottom layer. These particles are generally not fully fluidized, and the pores formed between them help to further disperse air bubbles, slow down the rising rate of air bubbles, increase the opportunity for particles to contact air bubbles, and facilitate the adhesion of air bubbles to the surface of hydrophobic particles, thereby enhancing the density difference between them and the hydrophilic gangue, improving the separation effect. Low-density fine particles are located at the top layer, in a critical fluidized state. They can respond to changes in fluid velocity and dynamically adjust their position, eliminating the negative impact of uneven radial velocity distribution and ensuring the balance and stability of the flow velocity across the entire column cross-section. The intermediate-sized particles of the two densities transition from bottom to top, which helps to improve the overall stability of the system. This arrangement fully utilizes the natural stratification effect of particles, improving sorting efficiency and fluidized bed stability.

[0057] Step 2: Supply clean water into the flotation cylinder 101 until the fluidization state of the filling medium 200 is stable.

[0058] Specifically, the third solenoid valve 504 is opened, and the clean water in the water mixing tank 300 is pressurized by the slurry pump 503 and then enters the flotation cylinder 101 as a fluidizing medium through the third delivery pipe 506 and the bubble generator 507. This fluidizes the filling medium 200 on the conical baffle 110 to adjust its spatial layout (i.e., natural stratification based on the differences in the properties of the filling medium 200) until the fluidization state of the filling medium 200 is stable (i.e., the reading of the pressure sensor 111 in the flotation cylinder 101 does not fluctuate significantly). Then the third solenoid valve 504 is closed.

[0059] Step 3: Inject raw ore pulp into flotation cylinder 101 for flotation. When a stirring assembly 112 is installed, turn on the stirring assembly 112 simultaneously.

[0060] Specifically, when the fourth solenoid valve 505 is opened, the raw slurry in the feed mixing tank 400 is pressurized by the slurry pump 503 and then enters the flotation cylinder 101 through the third conveying pipe 506 and the bubble generator 507. During this process, the high-speed flowing raw slurry generates micro-nano-sized bubbles due to cavitation. The surface roughness and cracks of the particles in the slurry provide abundant cavitation sites, which significantly improves the bubble generation efficiency.

[0061] It should be noted that during the sorting process, the flow rate of the fluidizing medium is controlled (the flow rate range is between 20-70 m³ / h). 3The velocity of the rising water flow is adjusted by adjusting the flow rate (typically between 1.0 and 4.0 m / s). Different flow velocities are generated as the fluidizing medium passes through pipes of different diameters. When the slurry passes through the bubble generator 507 (i.e., the Venturi tube), the fluid velocity increases significantly due to the narrowing of the pipe diameter. The rapidly flowing fluid generates negative pressure, thus inducing hydraulic cavitation and generating micro- and nano-sized bubbles. In the Venturi tube, to achieve the hydraulic cavitation effect, the flow velocity at the throat typically needs to reach 10-20 m / s or higher. The negative pressure generated when this high-speed fluid passes through the narrow section promotes hydraulic cavitation, thereby generating micro- and nano-sized bubbles.

[0062] The slurry containing micro- and nano-bubbles, acting as a fluidizing medium, forms a fluidized bed together with the packing medium 200. The particles to be separated undergo disturbance-induced settling motion according to their density, based on Archimedes' principle, thus completing the separation process. The introduced bubbles adhere to the surface of hydrophobic particles, increasing the density difference between them and the gangue particles. Specifically, the pores formed between the high-density coarse-grained packing medium 200 facilitate further bubble dispersion, slowing the bubble rise rate and increasing the opportunity for particle-bubble contact. This promotes bubble adhesion to the surface of hydrophobic particles, enhancing the density difference between them and the hydrophilic gangue, and improving the separation effect. The low-density fine-grained packing medium 200 can respond to changes in fluid velocity, dynamically adjusting its position to eliminate the negative impact of uneven radial velocity distribution, ensuring the balance and stability of the flow velocity across the entire column cross-section.

[0063] After sorting, the concentrate particles float to the surface and are collected through the overflow weir 103 to the concentrate outlet 104 for discharge, which is then sent to the next stage of dewatering. The tailings particles sink to the bottom of the fluidized bed, and the tailings accumulation status is monitored in real time by the pressure sensor 111. When the pressure reaches the preset upper limit, the tailings pipe 107 is automatically opened to discharge the tailings; when the pressure drops to the preset lower limit, the valve closes to prevent excessive discharge from causing a sudden change in fluidized bed pressure and to ensure the stability of the fluidized bed layer.

[0064] 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 fluidized bed flotation device for the separation and recovery of coarse-grained minerals, characterized in that, The flotation system includes a flotation cylinder and a packing medium. The flotation cylinder includes a flotation tube, a conical baffle, and a stirring assembly. The conical baffle is located at the lower end of the interior of the flotation tube. The packing medium is located on the conical baffle and has multiple layers inside the flotation tube. The particle diameter of the packing medium increases from top to bottom. The bottom layer of the flotation tube is a high-density packing medium with large particles, the middle layer is a packing medium with medium particles, and the top layer is a packing medium with low-density fine particles. The packing medium is selected from at least two different particle densities. The stirring assembly includes a drive motor, a stirring shaft, a stirring impeller, and an isolation screen. The isolation screen is located inside the flotation tank. The stirring impeller is mounted on the stirring shaft, the lower end of the stirring shaft is located in the isolation screen, and the upper end of the stirring shaft is connected to the drive motor. The filling medium is located in the isolation screen. The drive motor drives the stirring impeller to rotate, so that the filling medium can achieve low-speed stable rotation inside the isolation screen.

2. The fluidized bed flotation device for the separation and recovery of coarse-grained minerals according to claim 1, characterized in that, The flotation cylinder also includes an overflow weir and a tailings cone, which are respectively located at the upper and lower ends of the flotation cylinder.

3. The fluidized bed flotation device for separating and recovering coarse-grained minerals according to claim 2, characterized in that, The overflow weir is equipped with a concentrate outlet, and the bottom of the tailings cone is equipped with an emergency discharge pipe and a tailings pipe.

4. The fluidized bed flotation device for separating and recovering coarse-grained minerals according to claim 3, characterized in that, The accident discharge pipe is equipped with a first solenoid valve for controlling the on / off state of the accident discharge pipe, and the tailings pipe is equipped with a second solenoid valve for controlling the on / off state of the tailings pipe.

5. The fluidized bed flotation apparatus for the separation and recovery of coarse-grained minerals according to any one of claims 1-4, characterized in that, The flotation cylinder also includes multiple pressure sensors.

6. The fluidized bed flotation device for separating and recovering coarse-grained minerals according to claim 5, characterized in that, Multiple pressure sensors are arranged at equal intervals from top to bottom on the flotation cylinder.

7. The fluidized bed flotation apparatus for the separation and recovery of coarse-grained minerals according to any one of claims 1-4 and 6, characterized in that, The conical baffle is concentrically arranged with the flotation cylinder, and the diameter of the conical baffle is 7 / 10 to 9 / 10 of the inner diameter of the flotation cylinder.

8. The fluidized bed flotation apparatus for the separation and recovery of coarse-grained minerals according to any one of claims 1-4 and 6, characterized in that, The flotation cylinder is provided with a filling port for filling the filling medium.

9. The fluidized bed flotation device for separating and recovering coarse-grained minerals according to claim 2, characterized in that, The cone angle of the conical baffle is 5°-20°, and the cone angle of the tailings cone is 10°-30°.

10. A flotation method, characterized in that, The fluidized bed flotation apparatus according to any one of claims 1-9 is used to separate and recover coarse-grained minerals.

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