A flotation column with multi-stage mineralization

Abstract

The present invention belongs to the technical field of mineral separation and processing, and discloses a multi-stage mineralization flotation column. It comprises a flotation column, a concentrate tank, an internal tank body, a raw material feed assembly and a middling ore circulation assembly. The interior of the flotation column is divided into a separation zone, a mineralization zone and a tailings zone from top to bottom; the mineralization zone is divided into a main mineralization zone and a middling ore zone by the internal tank body, and the top and bottom of the internal tank body are porous plates. The raw material feed assembly transports the mineralized slurry to the main mineralization zone through a vertically downward discharge port, and the middling ore circulation assembly sprays the incompletely mineralized middling ore back into the internal tank body through at least one group of middling ore feed pipes, forming a multi-stage coordinated mineralization zone. The present invention solves the problems of incomplete mineralization, poor bubble stability, and easy clogging of equipment in the prior art through multi-stage mineralization, thereby improving the mineral recovery rate and flotation efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral separation and processing, and particularly relates to a multi-stage mineralization flotation column. Background Art

[0002] As the core equipment for mineral separation, the technological development of flotation columns has always revolved around improving mineralization efficiency, enhancing bubble stability and adapting to complex ore characteristics.

[0003] Traditional flotation columns employ varying mineralization methods and related processes. Domestically, KYZ-B and CCF flotation columns utilize direct air bubble generators, while KYZ-E flotation columns utilize a slurry and air mixed flow bubble generator. Cyclone static microbubble flotation columns combine pipe flow mineralization, cyclone force fields, and countercurrent collisions. Internationally, CISA flotation columns utilize static mixers to mix slurry and air, and their bubble generation systems include embedded static mixers and centrifugal pumps. Jameson flotation columns utilize efficient mineralization within downcomer mixers. Each type of flotation column generates bubbles through its own specific bubble generation and mineralization methods. These bubbles rise within the column and collide with mineral particles in the slurry, causing the mineral particles to adhere to the bubbles and achieve mineralization. However, these flotation columns commonly suffer from the instability of single-section aerators, resulting in poor bubble generation stability. Furthermore, most of these columns have single-section mineralization zones, resulting in incomplete mineralization and difficulty in allowing mineral particles to fully adhere to the bubbles, impacting the overall flotation effect and efficiency.

[0004] Patent CN117244700A discloses a flotation column that uses aeration and jet-assisted foaming, utilizing a high-pressure jet to draw in air and generate microbubbles. While this patent addresses the issue of oversized bubbles, it results in a single mineralized area, lacks segmented mineralization coordination, and low turbulence intensity within the cell, leading to incomplete mineralization and low resource utilization.

[0005] Patent CN112122008A discloses a central circulation, diversion-type cyclone aeration flotation device and method, which utilizes a cyclonic force field to enhance bubble-particle collisions. However, its mineralized zone remains a single structure, resulting in insufficient turbulence intensity, incomplete mineralization, and low resource utilization.

[0006] Patent CN205926036U discloses a pre-injection high-efficiency flotation column that avoids bubble generator blockage by tangentially injecting slurry. However, it also has the disadvantages of a single mineralization selection area, low turbulence intensity inside the tank, and no synergistic effect of the mineralization selection areas, resulting in low mineralization.

[0007] Based on traditional domestic and foreign technical solutions and attempts at improved technology, the existing flotation columns have the following problems:

[0008] (1) The mineralization area is single and incomplete, the turbulence intensity inside the main trough is low, and multiple mineralization zones have no synergistic effect, resulting in the loss of target minerals and tailings, and low resource utilization;

[0009] (2) Single aeration devices such as microporous foamers are prone to clogging, and impurities in the slurry can clog the micropores, which is not conducive to continuous production. Summary of the Invention

[0010] In view of at least one problem existing in the prior art, an object of the present invention is to provide a flotation column with multi-stage mineralization.

[0011] To achieve the purpose of the present invention, the specific technical solutions are as follows:

[0012] A multi-stage mineralization flotation column, comprising:

[0013] The flotation column is divided into a separation zone, a mineralization zone and a tailings zone from top to bottom. The bottom of the mineralization zone is provided with a middling discharge port, and the bottom of the tailings zone is provided with a tailings discharge port;

[0014] The concentrate tank is fixed on the upper part of the flotation column and is connected to the separation area of ​​the flotation column through the overflow port. The concentrate discharge port is set at the bottom of the concentrate tank;

[0015] The internal trough is provided in the mineralized area and divides the mineralized area into a main mineralized area and an intermediate mineralized area. The top and bottom of the internal trough are porous plate structures.

[0016] A raw material feeding assembly includes a raw material feeding foaming device and a raw material feeding gas-liquid mixing device connected to each other. The raw material feeding gas-liquid mixing device is provided with a raw material feeding pipe and a raw material discharging pipe. The raw material discharging pipe extends downward to the main mineralization zone and is provided with at least one raw material discharging port with the material discharging direction downward;

[0017] The intermediate ore circulation component includes a intermediate ore circulation pump connected to the intermediate ore discharge port and at least one group of intermediate ore feeding components respectively connected to the discharge ends of the intermediate ore circulation pump. The intermediate ore feeding component includes a connected intermediate ore feed foaming device and a intermediate ore feed gas-liquid mixing device. The intermediate ore feed gas-liquid mixing device is provided with a intermediate ore feed pipe and a intermediate ore discharge pipe. The intermediate ore feed gas-liquid mixing device is connected to the intermediate ore circulation pump through the intermediate ore feed pipe. The discharge port of the intermediate ore discharge pipe is arranged in the internal tank body. The discharge direction of at least one intermediate ore discharge pipe is arranged vertically opposite to the discharge direction of the raw material discharge pipe, and forms an offset.

[0018] Furthermore, the inner tank body is an axially centered structure with a smaller upper portion and a larger lower portion.

[0019] Furthermore, the upper-small-lower-large structure is a truncated cone or a polygonal pyramid.

[0020] Furthermore, the ratio of the height of the upper small and lower large structure to the height of the flotation column is 1:2-3.

[0021] Furthermore, the opening area of ​​the porous plate structure accounts for 75%-85% of the area of ​​the porous plate structure, and the area of ​​a single hole accounts for 5%-15% of the area of ​​the porous plate structure.

[0022] Furthermore, the discharge direction of the raw material discharge port is vertically downward.

[0023] Furthermore, at least two raw material discharge ports with downward discharge directions are provided in the main mineralized area.

[0024] Furthermore, the raw material discharge ports are arranged at the same horizontal height.

[0025] Furthermore, the raw material discharge port is located in the middle of the main mineralized area.

[0026] Furthermore, two groups of the intermediate ore feeding components are provided, and the corresponding intermediate ore discharge pipe openings are respectively located above and below the raw material discharge pipe opening, and the discharge direction of the intermediate ore discharge pipe located above is set upward; the discharge direction of the intermediate ore discharge pipe located below is set opposite to the discharge direction of the raw material discharge pipe in the vertical direction, and forms a hedge.

[0027] Furthermore, the discharge direction of the intermediate ore discharge pipe located above is arranged vertically upward.

[0028] Furthermore, the middling ore feeding assembly includes a first middling ore feeding assembly at the top and a second middling ore feeding assembly at the bottom;

[0029] The first intermediate ore feeding assembly includes a first intermediate ore feeding foaming device and a first intermediate ore feeding gas-liquid mixing device which are connected to each other. The first intermediate ore feeding gas-liquid mixing device is provided with a first intermediate ore feeding pipe, a first intermediate ore discharging pipe and a first gas-liquid conveying nozzle which is arranged opposite to the discharging direction of the raw material discharging pipe.

[0030] The second intermediate ore feeding assembly includes a second intermediate ore feeding foaming device and a second intermediate ore feeding gas-liquid mixing device which are connected to each other. The second intermediate ore feeding gas-liquid mixing device is provided with a second intermediate ore feeding pipe, a second intermediate ore discharging pipe and a second gas-liquid conveying nozzle which is arranged opposite to the discharging direction of the raw material discharging pipe.

[0031] Furthermore, the flow rate of the intermediate ore circulation pump is 2.0 to 3.0 times the feed flow rate of the raw material feed pipe.

[0032] Furthermore, a concentrate spraying device is provided on the top of the concentrate trough.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The present invention systematically solves the problems of incomplete mineralization, poor bubble stability, and easy clogging of existing flotation columns through the coordinated design of multiple mineralized areas, turbulence intensity gradient control, and foaming device layout, thereby improving flotation efficiency, resource utilization, and equipment reliability.

[0035] (2) The present invention can improve the efficiency of mineralization and recovery, and the multiple mineralization zones can operate in coordination, thereby extending the contact and action time between mineral particles and bubbles. Specifically, when the three-stage mineralization zone is set, the first stage of mineralization first causes the easily floated minerals to attach to bubbles, and the incompletely mineralized particles react again with the bubbles generated by the foaming device in the corresponding device and the internal tank body in the next two stages of mineralization. The second stage of mineralization is carried out on the basis of the first stage of mineralization zone, and the mineralized particles are recovered in coordination with the first stage of mineralization zone through the reaction force, and the incompletely mineralized particles in the first stage are returned to the intermediate ore for recovery; the third stage of mineralization and the second stage of mineralization have different turbulence intensities due to the difference in cross-sectional area of ​​the slurry flowing in the internal tank body. The turbulence intensity of the third stage of mineralization zone is greater than that of the second stage of mineralization zone, making the third stage of mineralization effect better than the second stage of mineralization zone, which can further increase the turbulence intensity inside the fluid field and increase the mineralization time of mineral particles and bubbles, so as to achieve the coordinated operation of the three stages of mineralization zone, reduce the loss of target minerals in tailings, improve the flotation recovery rate, and optimize resource utilization.

[0036] (3) The present invention can enhance the adaptability and stability of flotation. The combination of multi-stage mineralization and internal tank body and the rational layout of multiple components are conducive to handling slurries with different properties. When processing complex ores, by flexibly adjusting the parameters of each stage of mineralization conditions, a stable flotation effect is maintained, the impact of ore property fluctuations on flotation indicators is reduced, and the overall stability and reliability of the flotation process are improved.

[0037] (4) The present invention can reduce equipment maintenance. It uses multiple foaming devices and utilizes a mid-ore circulation system to optimize the path of slurry and bubbles, thereby dispersing the risk of blockage. When impurities accumulate locally in a component, the system's diversion and circulation will prevent the equipment from being paralyzed. This reduces the frequency of equipment shutdowns and cleaning caused by blockages, cuts maintenance costs, and ensures production continuity and economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 This is a structural diagram of a flotation column with multiple mineralization stages.

[0040] Figure 2 This is a structural diagram of the internal tank.

[0041] Among them: 1. Raw material feed foaming device; 2. Raw material feed gas-liquid mixing device; 3. Raw material feed pipe; 4. Concentrate tank; 5. Flotation column; 6. First middling ore feed foaming device; 7. First middling ore feed gas-liquid mixing device; 8. First middling ore feed pipe; 9. Second middling ore feed foaming device; 10. Second middling ore feed gas-liquid mixing device; 11. Second middling ore feed pipe; 12. Middling ore circulation pump; 13. Middling ore discharge port; 14. Tailings discharge port; 15. Second middling ore discharge pipe; 16. Second gas-liquid conveying nozzle; 17. Secondary mineralization zone; 18. First middling ore discharge pipe; 19. First gas-liquid conveying nozzle; 20. Tertiary mineralization zone; 21. Internal tank; 22. First raw ore conveying pipe section; 23. Second raw ore conveying pipe section; 24. Concentrate discharge port; 25. Concentrate spraying device; 26. Primary mineralization zone. DETAILED DESCRIPTION

[0042] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0043] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0044] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0045] like Figure 1 and 2 As shown, the present invention provides a multi-stage mineralization flotation column, comprising:

[0046] The flotation column 5 is divided into a separation zone, a mineralization zone and a tailings zone from top to bottom. The bottom of the mineralization zone is provided with a middling discharge port 13, and the bottom of the tailings zone is provided with a tailings discharge port 14;

[0047] The concentrate tank 4 is fixedly arranged on the upper part of the flotation column, belongs to the concentrate area, and is connected to the separation area of ​​the flotation column 5 through the overflow port. The concentrate discharge port 24 is set at the bottom of the concentrate tank 4;

[0048] The internal tank body 21 is provided in the mineralized area and divides the mineralized area into a main mineralized area and an intermediate mineralized area. The top and bottom of the internal tank body 21 are porous plate structures.

[0049] A raw material feeding assembly includes a raw material feeding foaming device 1 and a raw material feeding gas-liquid mixing device 2 connected to each other. The raw material feeding gas-liquid mixing device 2 is provided with a raw material feeding pipe 3 and a raw material discharging pipe. The raw material discharging pipe extends downward to the main mineralization zone and is provided with at least one raw material discharging port with the discharging direction downward;

[0050] The intermediate ore circulation component includes a intermediate ore circulation pump 12 connected to the intermediate ore discharge port 13 and at least one group of intermediate ore feeding components respectively connected to the discharge ends of the intermediate ore circulation pump 12. The intermediate ore feeding component includes a connected intermediate ore feed foaming device and a intermediate ore feed gas-liquid mixing device. The intermediate ore feed gas-liquid mixing device is provided with a intermediate ore feed pipe and a intermediate ore discharge pipe. The intermediate ore feed gas-liquid mixing device is connected to the intermediate ore circulation pump 12 through the intermediate ore feed pipe. The discharge port of the intermediate ore discharge pipe is arranged in the internal tank body 21. The discharge direction of at least one intermediate ore discharge pipe is arranged vertically opposite to the discharge direction of the raw material discharge pipe, and forms a hedge.

[0051] In a specific embodiment, the internal tank 21 is a truncated cone structure with a smaller top and a larger bottom, arranged axially in the center. This configuration increases internal turbulence intensity, and the upper and lower bottoms are composed of porous plates. During use, bubbles rise and slurry descends, ensuring a stable foam zone at the upper bottom and enhanced slurry flow at the lower bottom.

[0052] In a specific embodiment, the ratio of the height of the upper small and lower large structure to the height of the flotation column 5 is 1:2-3.

[0053] In a specific embodiment, the open area of ​​the porous plate structure accounts for 75%-85% of the area of ​​the porous plate structure, and the area of ​​a single hole accounts for 5%-15% of the area of ​​the porous plate structure. This arrangement allows for smooth flow of slurry between the internal tank body 21 and the flotation column 5, preventing clogging of the holes in the internal tank body 21.

[0054] In a specific embodiment, the slurry enters the flotation column 5 through the raw material feed pipe 3, and the raw material discharge pipe of the raw material feed gas-liquid mixing device 2 extends downward to the main mineralization area. At least two raw material discharge ports with downward discharge directions are set in the main mineralization area.

[0055] In a specific embodiment, the raw material discharge ports are arranged at the same horizontal height, and the raw material discharge ports are located in the middle of the main mineralized area.

[0056] In a specific embodiment, the discharge direction of the raw material discharge port is set vertically downward.

[0057] In a specific embodiment, the raw material feed gas-liquid mixing device 2 is arranged above the flotation column 5, the raw material feed pipe 3 is located on the upper side of the concentrate tank 4, and the raw material discharge pipe includes a first raw ore conveying pipe section 22 and a second raw ore conveying pipe section 23 arranged vertically in parallel. The slurry in the raw material feed gas-liquid mixing device 2 extends downward through the concentrate area and the separation area to the main mineralization area inside the flotation column through the raw material discharge pipe, forming two raw material discharge ports.

[0058] In a specific embodiment, two groups of the intermediate ore feeding components are provided, and the corresponding intermediate ore discharge pipe openings are respectively located above and below the raw material discharge pipe opening. The discharge direction of the intermediate ore discharge pipe located above is set upward; the discharge direction of the intermediate ore discharge pipe located below is set opposite to the discharge direction of the raw material discharge pipe in the vertical direction, and forms a hedge.

[0059] In a specific embodiment, the intermediate ore feed assembly includes a first intermediate ore feed assembly above and a second intermediate ore feed assembly below. The slurry can be transported to the first intermediate ore feed assembly and the second intermediate ore feed assembly respectively through the intermediate ore discharge port 13 and the intermediate ore circulation pump 12, and then enter the main mineralization area again.

[0060] The first intermediate ore feeding assembly includes a first intermediate ore feeding foaming device 6 and a first intermediate ore feeding gas-liquid mixing device 7 which are connected to each other. The first intermediate ore feeding gas-liquid mixing device 7 is provided with a first intermediate ore feeding pipe 8, a first intermediate ore discharging pipe 18 and a first gas-liquid conveying nozzle 19 located above the pipe opening of the raw material discharging pipe. The discharging direction of the first gas-liquid conveying nozzle 19 is arranged vertically upward.

[0061] The second intermediate ore feeding assembly includes a second intermediate ore feeding foaming device 9 and a second intermediate ore feeding gas-liquid mixing device 10 which are connected to each other. The second intermediate ore feeding gas-liquid mixing device 10 is provided with a second intermediate ore feeding pipe 11, a second intermediate ore discharging pipe 15 and a second gas-liquid conveying nozzle 16 which is opposite to the discharge direction of the raw material discharging pipe and forms a counter-attack.

[0062] The middling ore discharge port 13 and the middling ore circulation pump 12 work together to form a middling ore circulation system. The middling ore circulation system includes the first middling ore feed foaming device 6, the second middling ore feed foaming device 9, the first middling ore feed gas-liquid mixing device 7, the second middling ore feed gas-liquid mixing device 10, the first middling ore discharge pipe 18, and the second middling ore discharge pipe 15.

[0063] In a specific embodiment, a concentrate spraying device 25 is provided on the top of the concentrate chute 4 .

[0064] In a specific embodiment, a tailings discharge port 14 is provided at the bottom of the flotation column 5 to ensure efficient discharge of the tailings.

[0065] In a specific embodiment, the raw material feed foaming device 1, the first intermediate ore feed foaming device 6, and the second intermediate ore feed foaming device 9 can adopt inflation type, jet type, mechanical stirring type or composite foaming devices suitable for flotation columns on the market, including but not limited to microporous aeration devices, jet nozzle devices or swirl shear devices; the foaming devices are connected to their corresponding gas-liquid mixing devices, and are used to disperse the air into bubbles and mix them with the slurry in the gas-liquid mixing device.

[0066] In a specific embodiment, when using the multi-stage mineralization flotation column of the present invention:

[0067] The slurry enters the raw material feed gas-liquid mixing device 2 through the raw material feed pipe 3. The bubbles generated by the raw material feed foaming device 1 react with the slurry in the raw material feed gas-liquid mixing device 2. The bubbles then enter the internal tank body 21 through the first raw ore conveying pipe section 22 and the second raw ore conveying pipe section 23. The slurry forms a primary mineralization zone 26 in the internal tank body 21, which is called the first stage of mineralization. Mineral particles that are not fully mineralized and sink to the bottom of the mineralization zone pass through the internal tank body 21 and flow out of the intermediate ore discharge port 13 at the bottom of the mineralization zone. The intermediate ore flows out of the intermediate ore discharge port 13 and enters the intermediate ore circulation pump 12. Under the action of the intermediate ore circulation pump 12, it is divided into two streams of slurry and enters the first intermediate ore feed pipe 8 and the second intermediate ore feed pipe 11 respectively.

[0068] The middlings enter the second middling feed gas-liquid mixing device 10 together with the bubbles generated by the second middling feed foaming device 9 through the second middling feed pipe 11 and are then fully reacted. The middlings are then transported to the internal tank 21 through the second middling discharge pipe 15 and then ejected from the second gas-liquid delivery nozzle 16 to form a secondary mineralization zone 17, referred to as the second stage of mineralization. The second stage of mineralization is carried out on the basis of the first stage of mineralization. The middling circulation pump 12 delivers a force in the opposite direction to the primary mineralization, and the middlings cooperate with the first stage of mineralization to recover mineralized particles. The incompletely mineralized particles in the first stage are returned for middling recovery.

[0069] The intermediate ore enters the first intermediate ore feed gas-liquid mixing device 7 through the first intermediate ore feed pipe 8 together with the bubbles generated by the first intermediate ore feed foaming device 6. After sufficient action, it is transported to the internal tank body 21 through the first intermediate ore discharge pipe 18 and then sprayed out by the first gas-liquid delivery nozzle 19 to form a tertiary mineralization zone 20, which is called the third stage mineralization.

[0070] The third and second mineralization stages have different turbulence intensities due to the different cross-sectional areas through which the slurry flows in the internal trough 21. The turbulence intensity in the third mineralization zone is greater than that in the second mineralization zone, and the probability of collision between bubbles and particles is increased, making the third mineralization effect better than the second mineralization zone. This can further increase the turbulence intensity within the fluid field, prolong the mineralization time of mineral particles and bubbles, and improve the recovery rate.

[0071] The flotation tailings (unmineralizable gangue minerals) are discharged from the flotation column 5 through the tailings discharge port 14 ; the flotation concentrate overflows into the concentrate tank 4 at the upper end of the flotation column 5 under the support of the flotation bubbles, and the concentrate is collected uniformly through the concentrate discharge port 24 .

[0072] In this embodiment, a concentrate spraying device 25 is provided above the overflow port to clean the foam. After being sprayed and cleaned by the concentrate spraying device 25, the cleaning liquid flows out from the concentrate discharge port 24 of the concentrate tank 4 as flotation concentrate, further improving product quality and increasing the recovery rate.

[0073] In this embodiment, each slurry pipeline is equipped with a one-way valve to prevent slurry backflow and damage to the equipment. In a specific embodiment, the suction force of the intermediate ore circulation pump 12 can efficiently draw the slurry. The slurry delivered by the intermediate ore circulation pump 12 must be opposite to the direction of primary mineralization and meet the requirements of injection. Therefore, the pumping pressure and flow rate of the intermediate ore circulation pump 12 are relatively high. The flow rate of the intermediate ore circulation pump 12 is 2.0 to 3.0 times the feed rate of the raw material feed pipe 3. This flow difference design forms a systematic match with the functional requirements of each pump in the slurry circulation path and sorting stage within the flotation column, and the mutual cooperation ensures the stable and efficient operation of the flotation column.

[0074] In this embodiment, the raw material feed pipe 3 and the middling circulation assembly discharge in opposite directions, and the slurry flows in opposite directions. Specifically, the piping system formed by the raw material feed pipe 3 and the middling circulation assembly creates a countercurrent flow between the slurry and the bubbles. The high turbulence intensity within the internal tank 21 increases the turbulence intensity within the internal mineralized zone, thereby extending the contact time between the mineral and the bubbles. The circulation flow rate is controlled by controlling the pressure of the middling circulation pump 12. The circulation flow rate of the flotation column influences the mineral separation efficiency. Increasing the pressure increases the circulation flow rate, thereby improving the recovery rate of the target mineral.

[0075] The multi-stage mineralization flotation column provided in this embodiment adopts a multi-stage mineralization, multiple-inflating mechanism and the addition of an internal truncated cone trough to systematically optimize the internal structure of the flotation column. In terms of multi-stage mineralization, multiple mineralization reaction sites are constructed by designing different areas or height intervals inside the flotation column; in order to solve the problem that a single inflation device is prone to clogging, a multiple inflation strategy is introduced to abandon the limitations of the traditional single inflation mode; the addition of an internal truncated cone trough increases the turbulence intensity inside the mineralized area, and the energy inside different areas is different, which increases the probability of bubble and particle collision and improves the overall mineralization efficiency, providing a more advantageous and potential technical solution for the field of mineral flotation.

[0076] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the present invention.

Claims

1. A multi-stage mineralization flotation column, characterized in that: include: The flotation column is divided into a separation zone, a mineralization zone and a tailings zone from top to bottom. The bottom of the mineralization zone is provided with a middling discharge port, and the bottom of the tailings zone is provided with a tailings discharge port; The concentrate tank is fixed on the upper part of the flotation column and is connected to the separation area of ​​the flotation column through the overflow port. The concentrate discharge port is set at the bottom of the concentrate tank; The internal trough is provided in the mineralized area and divides the mineralized area into a main mineralized area and an intermediate mineralized area. The top and bottom of the internal trough are porous plate structures. A raw material feeding assembly includes a raw material feeding foaming device and a raw material feeding gas-liquid mixing device connected to each other. The raw material feeding gas-liquid mixing device is provided with a raw material feeding pipe and a raw material discharging pipe. The raw material discharging pipe extends downward to the main mineralization zone and is provided with at least one raw material discharging port with the material discharging direction downward; A middling ore circulation assembly includes a middling ore circulation pump connected to a middling ore discharge port and at least one group of middling ore feeding assemblies connected to the discharge ends of the middling ore circulation pump, wherein the middling ore feeding assembly includes a middling ore feeding foaming device and a middling ore feeding gas-liquid mixing device connected to each other, the middling ore feeding gas-liquid mixing device being provided with a middling ore feeding pipe and a middling ore discharging pipe, the middling ore feeding gas-liquid mixing device being connected to the middling ore circulation pump via the middling ore feeding pipe, the discharge port of the middling ore discharging pipe being provided in an internal tank body, and the discharge direction of at least one middling ore discharging pipe being arranged vertically opposite to the discharge direction of the raw material discharging pipe, and forming an offset; The intermediate ore feeding components are provided in two groups, and the corresponding intermediate ore discharge pipe openings are respectively located above and below the raw material discharge pipe opening. The discharge direction of the intermediate ore discharge pipe located above is set upward; the discharge direction of the intermediate ore discharge pipe located below is set opposite to the discharge direction of the raw material discharge pipe in the vertical direction, and forms a hedge.

2. The multi-stage mineralization flotation column according to claim 1, characterized in that: The inner tank body is an axially centered structure with a small top and a large bottom.

3. The multi-stage mineralization flotation column according to claim 2, characterized in that: The structure with a small top and a large bottom is a truncated cone or a polygonal pyramid.

4. The multi-stage mineralization flotation column according to claim 2, characterized in that: The ratio of the height of the upper small and lower large structure to the height of the flotation column is 1:2-3.

5. The multi-stage mineralization flotation column according to any one of claims 1 to 4, characterized in that: The opening area of ​​the porous plate structure accounts for 75%-85% of the area of ​​the porous plate structure, and the area of ​​a single hole accounts for 5%-15% of the area of ​​the porous plate structure.

6. The multi-stage mineralization flotation column according to claim 1, characterized in that: At least two raw material discharge ports with downward discharge directions are set in the main mineralization area.

7. The multi-stage mineralization flotation column according to claim 6, characterized in that: The raw material discharge port is located in the middle of the main mineralized area.

8. The multi-stage mineralization flotation column according to claim 1, characterized in that: The middling ore feeding assembly comprises a first middling ore feeding assembly at the top and a second middling ore feeding assembly at the bottom; The first intermediate ore feeding assembly includes a first intermediate ore feeding foaming device and a first intermediate ore feeding gas-liquid mixing device which are connected to each other. The first intermediate ore feeding gas-liquid mixing device is provided with a first intermediate ore feeding pipe, a first intermediate ore discharging pipe and a first gas-liquid conveying nozzle which is arranged opposite to the discharging direction of the raw material discharging pipe. The second intermediate ore feeding assembly includes a second intermediate ore feeding foaming device and a second intermediate ore feeding gas-liquid mixing device which are connected to each other. The second intermediate ore feeding gas-liquid mixing device is provided with a second intermediate ore feeding pipe, a second intermediate ore discharging pipe and a second gas-liquid conveying nozzle which is arranged opposite to the discharging direction of the raw material discharging pipe.

9. The multi-stage mineralization flotation column according to claim 1, characterized in that: The flow rate of the intermediate ore circulation pump is 2.0 to 3.0 times the feed flow rate of the raw material feed pipe.

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