Three-section type flotation machine suitable for efficient separation of wide particle fraction

Abstract

The three-section type flotation machine comprises a flotation tank, a concentrate tank and a tailing discharge bin, and the flotation tank comprises a high turbulence cavity located on the lower portion of the flotation tank, a middle turbulence cavity located in the middle of the flotation tank and a low turbulence foam separation area located on the upper portion of the flotation tank. The high-turbulence chamber is used for recovering minerals with superfine particle fractions in ore pulp, the middle-turbulence chamber is used for recovering minerals with conventional fine particle fractions in the ore pulp, and the low-turbulence foam separation area is used for separating and recovering mineralized foams. According to the three-section type flotation machine, multi-turbulence separation and static separation are mainly combined, multi-turbulence separation is divided into two parts, namely, high turbulence and medium turbulence are sequentially arranged from the lower portion of a flotation tank and are used for recycling micro-fine particles and particles of a conventional flotation fraction respectively, and static separation is achieved. The relative static environment provided by the upper low-turbulence foam separation area can achieve efficient separation of ore pulp and foam, so that the flotation effect can be effectively improved, and the flotation device can be suitable for efficient separation of whole-fraction particles. The three-section type flotation machine is wide in flotation fraction range, high in speed, small in occupied area, high in energy utilization rate and wide in application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral flotation devices, and particularly relates to a three-stage flotation machine suitable for efficient separation of wide particle sizes. Background Art

[0002] With the development and utilization of mineral resources, lean, fine, and complex mineral resources will increasingly become the main source of resources, resulting in an increasing proportion of -20μm fine particles in the flotation separation process. The industry faces the problem of how to efficiently utilize this part of the resources; in order to achieve the efficient utilization of low-grade mineral resources, the efficient flotation separation and recovery of -20μm fine particles is particularly important.

[0003] The effective separation particle size range of conventional flotation equipment is only between 20μm - 120μm, and it is difficult to recover fine particles below 20μm well, bringing new challenges to the mineral flotation industry. Therefore, it is urgent to develop efficient ore dressing technologies to address the micro-scale effect of minerals.

[0004] Jet microbubble flotation is a commonly used fine particle flotation technology, among which the Australian Jameson Cell is the most representative. The Jameson Cell allows bubbles and particles to come into full contact through a downcomer. The feed slurry is pumped into the downcomer through an orifice plate to form a high-pressure jet, which jets downward to shear the liquid and entrain natural air. Due to the high mixing speed and large contact area, the particles can quickly come into contact and be collected; subsequently, the aerated mixture leaves the downcomer and enters the pulp area of the flotation cell, where the secondary contact between bubbles and particles occurs. Bubbles detach from the pulp, and hydrophobic substances in the pulp selectively attach to the tiny bubbles under the action of reagents to form mineralized bubbles; the mineralized bubbles float upward under the action of buoyancy, reach the liquid surface of the flotation cell to form a foam layer, continuously accumulate and overflow from the overflow port of the flotation cell to become flotation concentrate, while the tailings that are not flotated remain at the bottom of the flotation cell, thus achieving mineral separation. In addition, there is also a Stack Cell flotation machine, which is a fine particle high-efficiency flotation device developed by Eriez Company. The StackCell adopts a unique two-stage design to separate the particle collection chamber from the phase separation process. In the particle collection chamber, high energy is focused on bubble-particle collisions to improve the attachment efficiency; while in the separation chamber, the reduced energy input reduces the mixing degree, improves the concentrate grade, and shortens the residence time, thereby increasing the throughput. Different from traditional flotation machines, the Stack Cell mainly uses energy to shear air to generate tiny bubbles, while maximizing the attachment effect between bubbles and particles, avoiding energy waste on inefficiently agitated pulp, reducing energy consumption by 35 - 40% compared to traditional flotation machines, and reducing air demand by about 30%, with significant energy-saving effects.

[0005] Although the above-mentioned Jameson Cell and Stack Cell have good flotation effects on -20μm fine particles, the excessive turbulence has a poor flotation effect on a large number of remaining conventional-sized particles in the pulp.

[0006] Therefore, it is necessary to design a three-stage flotation machine suitable for efficient separation of wide particle sizes. Through the coordination of multi-level turbulence intensities, while floating fine particles, it also takes into account the recovery of conventional-sized particles, realizing efficient separation of wide particle sizes. Summary of the Invention

[0007] The present invention overcomes the deficiencies existing in the process of floating fine particles by existing flotation machines, and provides a three-stage flotation machine suitable for efficient separation of wide particle sizes. It not only enhances the strong shear of bubbles, reduces the bubble size and increases the probability of collision between fine particles and bubbles. At the same time, a high-turbulence chamber, a medium-turbulence chamber and a low-turbulence foam separation zone are arranged in the flotation cell. The high-turbulence chamber is used for floating ultrafine particle-sized minerals, the medium-turbulence chamber is used for floating conventional fine particle-sized minerals and reducing the desorption of conventional fine particle-sized minerals, strengthening the flotation effect while improving the recovery rate.

[0008] To achieve the above object, the technical solution adopted by the present invention is: A three-stage flotation machine suitable for efficient separation of wide particle sizes, including a flotation cell, a concentrate tank and a tailing discharge bin. The concentrate tank is communicated with the upper end of the flotation cell. The flotation cell includes a high-turbulence chamber located at the lower part of the flotation cell, a medium-turbulence chamber located in the middle of the flotation cell and a low-turbulence foam separation zone located at the upper part of the flotation cell. The high-turbulence chamber is located in the sunken area at the bottom of the flotation cell, and a high-turbulence bubble mineralization mechanism is arranged in the high-turbulence chamber. The medium-turbulence chamber is located above the high-turbulence chamber, and a medium-turbulence bubble mineralization mechanism is arranged in the medium-turbulence chamber. The high-turbulence chamber is used for recovering minerals of ultrafine particle size in the pulp, the medium-turbulence chamber is used for recovering minerals of conventional fine particle size in the pulp, the low-turbulence foam separation zone is used for separating and recovering mineral foam, and the tailing discharge bin is communicated with the side wall at the lower end of the medium-turbulence chamber.

[0009] Further, a high-turbulence bubble mineralization mechanism is arranged in the high-turbulence chamber. The medium-turbulence chamber is located above the high-turbulence chamber, and a medium-turbulence bubble mineralization mechanism is arranged in the medium-turbulence chamber. An overflow weir is arranged in the low-turbulence foam separation zone.

[0010] Further, the medium-turbulence bubble mineralization mechanism includes a low-damping direct-suspension stator and an impeller, and the low-turbulence foam separation zone is a foam enrichment area.

[0011] Furthermore, the high-turbulence bubble mineralization mechanism includes a multi-stage rotor-stator structure, an adjustable axial sliding coupling, and a variable-frequency motor for driving the rotation of the hollow shaft. The adjustable axial sliding coupling is used to adjust the height of the multi-stage rotor, thereby adjusting the size of the gap between the multi-stage rotor and the stator. The rotor includes a hollow shaft inserted into the high-turbulence chamber and a plurality of rotor plates arranged on the hollow shaft. The stator includes a plurality of stator plates arranged on the inner wall of the high-turbulence chamber. The stator plates and the rotor plates are in an interlocking structure. During the rotation of the rotor plates relative to the stator plates, there is always a gap for the pulp to pass through between them.

[0012] Furthermore, a plurality of rotor plates in the high-turbulence chamber are radially distributed around the hollow shaft, and a plurality of stator plates are evenly spaced along the circumferential direction of the inner wall of the high-turbulence chamber, and the stator plates and the rotor plates are staggered in the vertical direction.

[0013] Furthermore, the rotor plates and the stator plates are respectively arranged at intervals to form convex parts and concave parts. The rotor convex parts, stator convex parts, rotor concave parts, and stator concave parts are in a trapezoidal structure, and a plurality of rotor plates and stator plates are all in a hollow structure, and the hollow structure is similar to a "mouth" shape.

[0014] Furthermore, the low-damping direct-suspension stator is a radial short blade, and the impeller is located inside the low-damping direct-suspension stator, and the installation position of the impeller is lower than that of the low-damping direct-suspension stator.

[0015] Furthermore, the fixed end of the adjustable axial sliding coupling is connected to the output shaft of the variable-frequency motor, and the sliding end is connected to the top end of the hollow shaft. The cavity inside the hollow shaft forms an air inlet cavity, and the air intake volume is controlled by an air intake mechanism. The air intake mechanism includes a gas flow meter, an air intake valve, a controller, a high-pressure tank, and an air compressor.

[0016] Furthermore, the upper end of the air inlet cavity is communicated with the air intake mechanism, and the lower end is communicated to the lower part of the high-turbulence chamber. The side and bottom of the lower end of the air inlet cavity are provided with air outlet openings. A feed inlet is provided at the bottom of the lowermost end of the high-turbulence chamber, and a controllable valve is arranged at the feed inlet. The controllable valve is used to adjust the feed speed of the flotation machine.

[0017] Furthermore, a washing and spraying water device is arranged above the flotation cell, which can reduce the gangue entrainment in the concentrate foam to improve the concentrate grade, and wash the foam from the concentrate tank to the concentrate outlet.

[0018] The beneficial effects of the present invention are: (1) The present invention provides a three-stage flotation machine suitable for efficient separation of wide particle size ranges. The flotation cell of the present invention is divided into a lower high-turbulence chamber, a middle medium-turbulence chamber, and an upper low-turbulence foam separation zone. Compared with the Stack Cell flotation machine, when the pulp mixture flows through the multi-stage rotor-stator in the high-turbulence chamber to the low-damping direct-suspension stator-impeller in the upper middle-turbulence chamber, the three-stage flotation machine of the present invention can not only efficiently recover fine particles, but also reduce the shedding of conventional particle size particles (20 - 120 microns). Therefore, the recovery rates of fine particles and conventional particle size particles are improved.

[0019] (2) With the help of the inner cavity structure in the high-turbulence chamber of the present invention, air is transmitted by the hollow rotating shaft to the lower part of the high-turbulence chamber, and is strongly stirred and sheared by the multi-stage rotor-stator in the high-turbulence chamber to form micro-bubbles, increasing the collision probability between the bubbles and the fine particles. Due to the increase in the collision rate and the characteristic that fine particles are more likely to adhere to micro-bubbles, not only can the recovery rate of fine particles be improved, but also the residence time can be shortened and the throughput can be increased.

[0020] (3) With the help of the impeller and stator structure of the KYF flotation machine in the middle-turbulence chamber of the present invention, in the middle-turbulence chamber, since the turbulence intensity is relatively smaller than that in the high-turbulence chamber, the shedding of conventional particle size particles or coarse particles is reduced. At the same time, due to the unique design of the high specific speed and backward-tilted blades of the KYF flotation machine impeller, the pulp flowing through this area provides the opportunity for the mineralization of conventional particle size particles, realizing the recovery of conventional particle size particles. By conveniently adjusting the turbulence intensity of the high-turbulence chamber and the middle-turbulence chamber through an adjustable axial sliding coupling, the adaptability of the three-stage flotation machine of the present invention to different feed pulps is enhanced. Description of the Drawings

[0021] Figure 1 is a schematic cross-sectional structure diagram of the three-stage flotation machine suitable for efficient separation of wide particle size ranges of the present invention; Figure 2 is a schematic external structure diagram of the rotor of the present invention; Figure 3 is a schematic external structure diagram of the high-turbulence chamber with a stator of the present invention; Figure 4 is a schematic bottom view structure diagram of the low-damping direct-suspension stator-impeller of the present invention; Figure 5 is a schematic external structure diagram of the impeller of the present invention; Figure 6 is a schematic external structure diagram of the low-damping direct-suspension stator of the present invention Figure 7 is a comparison chart of flotation recovery rates of flotation experiments on anthracite slime from a certain mine in Henan; Figure 8 is a comparison chart of concentrate ash content of flotation experiments on anthracite slime from a certain mine in Henan.

[0022] Description of the reference numerals: In the figure: 1 - flotation cell; 2 - concentrate tank; 3 - high-turbulence chamber; 31 - rotor; 32 - stator; 33 - hollow rotating shaft; 34 - variable-frequency motor; 331 - rotor plate; 332 - stator plate; 3311 - rotor projection; 3312 - rotor recess; 3321 - stator projection; 3322 - stator recess; 35 - adjustable axial sliding coupling; 4 - medium-turbulence chamber; 41 - low-damping directly suspended stator; 42 - impeller; 43 - overflow weir; 5 - tailings discharge bin; 51 - telescopic plate; 52 - drive mechanism; 53 - tailings discharge pipe; 54 - tailings outlet; 6 - feed inlet; 7 - air outlet; 8 - concentrate outlet; 9 - air inlet. Detailed implementation manners

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "right", "vertical", "bottom", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0025] The present invention provides a three-stage flotation machine suitable for efficient separation of wide particle sizes, as Figure 1-6 shown, comprising a flotation cell 1, a concentrate tank 2 and a tailings discharge bin 5. The concentrate tank 2 is communicated with the upper end of the flotation cell 1. The flotation cell 1 includes a high-turbulence chamber 3 located at the lower part of the flotation cell 1, a medium-turbulence chamber 4 located in the middle of the flotation cell 1 and a low-turbulence foam separation zone located at the upper part of the flotation cell 1. The high-turbulence chamber 3 is located in the sunken tank body area at the bottom of the flotation cell 1. A high-turbulence bubble mineralization mechanism is arranged in the high-turbulence chamber 3. The medium-turbulence chamber 4 is located above the high-turbulence chamber 3. A medium-turbulence bubble mineralization mechanism is arranged in the medium-turbulence chamber 4. An overflow weir 43 is arranged at the upper part of the low-turbulence foam separation zone. A relatively static separation mechanism is arranged at the overflow weir 43. The tailings discharge bin 5 is communicated with the lower end of the medium-turbulence chamber 4; The medium-turbulence chamber 4 is for the area of flotation of conventional-sized particles. The area of flotation of conventional-sized particles is located between the low-turbulence foam separation area and the high-turbulence chamber 3. The medium-turbulence bubble mineralization mechanism includes a low-damping directly suspended stator 41 and an impeller 42. The low-turbulence foam separation area includes a foam enrichment area and an overflow weir 43. An overflow weir 43 is arranged on one side above the upper low-turbulence foam separation area. A concentrate tank 2 is installed outside the overflow weir 43. A concentrate outlet 8 is installed at the bottom of the concentrate tank 2. A tailings discharge pipeline 53 is installed at the lower side wall of the medium-turbulence chamber 4. The tailings discharge pipeline 53 is communicated with the tailings discharge bin 5.

[0026] The tailings discharge bin 5 includes a driving mechanism 52, a telescopic plate 51, a tailings discharge pipeline 53 and a tailings outlet 54. The driving mechanism 52 is arranged above the telescopic plate 51 and is used to control the elongation and shortening of the telescopic plate 51. The liquid level in the tailings discharge bin 5 is controlled by the elongation and shortening of the telescopic plate 51. The tailings discharge pipeline 53 is arranged on one side of the tailings discharge bin 5 close to the medium-turbulence chamber 4. The tailings outlet 54 is arranged on one side of the tailings discharge bin 5 away from the tailings discharge bin 5.

[0027] The high-turbulence bubble mineralization mechanism includes a multi-stage rotor 31 - stator 32 structure, an adjustable axial sliding coupling 35 and a variable-frequency motor 34 for driving the rotation of a hollow rotating shaft 33. The adjustable axial sliding coupling 35 is used to adjust the height of the multi-stage rotor 31, and thus adjust the size of the gap between the multi-stage rotor 31 and the stator 32. The rotor 31 includes a hollow rotating shaft 33 inserted into the high-turbulence chamber 3 and a plurality of rotor plates 331 arranged on the hollow rotating shaft 33. The stator 32 includes a plurality of stator plates 332 arranged on the inner wall of the high-turbulence chamber 3. The stator plates 332 and the rotor plates 331 are of an interlocking structure. There is always a gap for the pulp to pass through between the two during the rotation of the rotor plates 331 relative to the stator plates 332. The gaps between a plurality of rotor plates 331 and stator plates 332 are the same.

[0028] In the present invention, a plurality of rotor plates 331 in the high-turbulence chamber 3 are radially distributed around the hollow rotating shaft 33. A plurality of stator plates 332 are evenly spaced along the circumferential direction of the inner wall of the high-turbulence chamber, and the stator plates 332 and the rotor plates 331 are staggered in the vertical direction. In a preferred example, along the horizontal direction of the high-turbulence chamber 3, the rotor plates 331 and the stator plates 332 are respectively arranged at intervals to form a convex part and a concave part, and the rotational fit is achieved through an interlocking structure: among them, the rotor convex part 3311 passes through the stator concave part 3322 during rotation to form an interlocking structure. The shapes of the rotor convex part 3311 and the stator concave part 3322 match each other, and the shapes of the stator convex part 3321 and the rotor concave part 3312 also match each other. When the rotor plate 331 rotates relative to the stator plate 332, gaps for the slurry to pass through are formed between the rotor convex part 3311 and the stator concave part 3322, and between the stator convex part 3321 and the rotor concave part 3312; In a preferred embodiment, Figure 1 , Figures 3-5 As shown, the rotor convex part 3311, the stator convex part 3321, the rotor concave part 3312 and the stator concave part 3322 are trapezoidal structures, and the rotor plates 331 and the stator plates 332 are all hollow structures, and the hollow structures are similar to the "mouth" shape. The turbulence intensity of the high turbulence chamber 3 is adjusted accordingly by adjusting the gap between the rotor plate 331 and the stator plate 332 through the adjustable axial sliding coupling 35. When the gap between the rotor plate 331 and the stator plate 332 above or below it is reduced, the turbulence intensity of the high turbulence chamber 3 is increased. When the gap between the rotor plate 331 and the stator plate 332 above or below it is increased, the turbulence intensity of the high turbulence chamber 3 is reduced. When the gap between the rotor plate 331 and the stator plate 332 above and below it is equal, the turbulence intensity of the high turbulence chamber 3 is minimized.

[0029] In a preferred embodiment, the low-damping direct-suspended stator 41 is a radial short blade, the impeller 42 is located inside the low-damping direct-suspended stator 41, and the installation position of the impeller 42 is lower than the low-damping direct-suspended stator. The turbulence intensity of the medium turbulence chamber 4 is adjusted by adjusting the length of the adjustable axial sliding coupling 35, and adjusting the projected overlap area between the low-damping direct-suspended stator 41 and the impeller 42 in the diameter direction of the impeller 42 to make corresponding adjustments. When the projected overlap area between the low-damping direct-suspended stator 41 and the impeller 42 in the diameter direction of the impeller 42 increases, the turbulence intensity of the medium turbulence chamber 4 increases, and when the projected overlap area between the low-damping direct-suspended stator 41 and the impeller 42 in the diameter direction of the impeller 42 decreases, the turbulence intensity of the medium turbulence chamber 4 decreases.

[0030] In a preferred embodiment, the cavity inside the hollow shaft forms an air intake cavity, and the air intake amount is controlled by an air intake mechanism, which includes a gas flow meter, an air intake valve, a controller, a high-pressure tank and an air compressor.

[0031] In a preferred embodiment, the upper end of the air inlet chamber is communicated with the air inlet mechanism, and the lower end is communicated below the high-turbulence chamber 3. The side surface and the bottom of the lower end of the air inlet chamber are provided with air outlet openings 7. The bottom of the lowest end of the high-turbulence chamber 3 is provided with a feed inlet 6, and a controllable valve is arranged at the feed inlet 6. The controllable valve is used for adjusting the feeding speed of the flotation machine. A washing water device is arranged above the flotation cell 1, which can reduce the gangue entrainment in the concentrate foam to improve the concentrate grade, and wash the foam from the concentrate tank 2 to the concentrate outlet 8.

[0032] The working principle of the present invention is as follows: Adjust the relative positions of the fixed end and the sliding end of the adjustable axial sliding coupling and fasten them with bolts to adjust the turbulence intensity of the high-turbulence chamber 3 and the medium-turbulence chamber 4. Start the variable-frequency motor 34 to drive the adjustable axial sliding coupling 35 to operate through the pulley, so as to drive the hollow rotating shaft 33 to rotate. The pulp and gas enter from the bottom feed inlet 6 and the air inlet 9 above the hollow rotating shaft 33 respectively, and then are dispersed into the entire high-turbulence chamber 3. The mixture of gas and pulp is first mixed in the high-turbulence bubble mineralization area in the high-turbulence chamber 3. Due to the strong stirring action of the rotor 31 and the stator 32, a violent turbulence area with highly concentrated energy transmission is formed. The initially dispersed bubbles are broken up into tiny bubbles under the violent rotation, and the hydrophobic ultrafine particles with a size of -20 mm in the pulp collide with the tiny bubbles sufficiently and are adsorbed, thus realizing efficient mineralization. Secondly, the pulp mixture flows through the medium-turbulence chamber 4 into the medium-turbulence bubble mineralization area formed by the low-damping direct-suspension stator 41 and the impeller 42. The turbulence intensity in this area is relatively weaker than that in the high-turbulence area, which can reduce the shedding of hydrophobic fine particles while recovering the conventional-sized particles with a size of +20 mm, thus realizing the flotation of all-size particles. The pulp passing through the high- and medium-turbulence areas moves upward, enters the low-turbulence foam separation area to form a stable foam layer, then flows into the overflow weir 43 and finally enters the concentrate tank 2. The obtained concentrate is discharged from the concentrate outlet 8, and the final tailings flow through the tailings discharge pipeline 53 into the tailings discharge bin 5 and are discharged from the tailings outlet 54.

[0033] The flotation process of the present invention starts continuously. The pulp enters the high-turbulence chamber 3 through the feed port 6, and the gas enters through the upper air inlet 9 of the hollow rotating shaft 33 and is dispersed to the bottom air outlet 7 of the high-turbulence chamber 3. The frequency conversion motor 34 is turned on and the rotation speed is set to drive the rotor 31 and the impeller 42 to rotate in the turbulent flotation area, generating high- and medium-shear turbulent kinetic energy regions respectively with the stator 32 and the low-damping directly suspended stator 41. The pulp mixture that initially enters the high-turbulence chamber 3 is strongly stirred by the rotor 31 and the stator 32, and the ore particles are suspended and collide with the generated micro-bubbles. After mineralization, the bubbles and the pulp gradually rise into the medium-turbulence chamber 4, passing through the medium-turbulence bubble mineralization area formed by the low-damping directly suspended stator 41 and the impeller 42, so that the conventional particle size particles or partially detached particles are mineralized again. The mineralized bubbles rise to the flotation cell 1 and accumulate to form a stable foam layer. The flushing water sprayed by the top flushing water device washes the more hydrophobic particles or gangue minerals entrained in the foam back into the pulp. After the gangue minerals are separated, they are discharged through the tailings discharge pipe 53 at the bottom of the medium-turbulence chamber 4. The foam carrying the concentrate flows into the concentrate tank 2 through the top overflow weir 43 and is discharged from the concentrate port 8 to complete the entire flotation separation process.

[0034] The following takes the anthracite slime of a certain mine in Henan as an example to conduct a flotation experiment to further illustrate the present invention.

[0035] Example 1 In this embodiment, as a preferred method, in the direction of the rotor convex part 3311 extending from the hollow rotating shaft 33 to the inner wall of the high-turbulence chamber 3, the height of the rotor convex part 3311 gradually decreases. In the direction of the stator convex part 3321 extending from the inner wall of the high-turbulence chamber 3 to the hollow rotating shaft 33, the height of the stator convex part 3321 also gradually decreases, as Figure 2 、 Figure 3 shown. The hollow structure is a hollow area with a specific shape formed on the component body. The hollow area is similar to a "mouth" shape and is a hollow structure constructed by removing part of the solid material, as Figure 2 、 3 shown.

[0036] Test Example Using the three-stage flotation machine of Example 1 (denoted as KJF-CN20L), a flotation experiment was conducted on the anthracite slime of a certain mine in Henan. The floating particle size P(50) = 20μm, P(80) = 120μm, the pulp concentration was 7 - 9%, the reagents used were kerosene and MIBC, the feed amount was 40L, and the aeration amount was 60L / min. The curves of the cumulative recovery rate and concentrate ash content of coal under this condition are as Figure 7 、 8 shown. The flotation ended at 5 minutes, the recovery rate reached 79.9%, and the concentrate ash content was 12.6%.

[0037] As a comparative example, under the flotation conditions of the same reagent regime and aeration ratio, using a conventional flotation machine with a 20L capacity in the laboratory (laboratory small flotation machine, model: XFD-20L), the flotation was completed in 30 minutes, with a recovery rate of 78.9% and the ash content of the concentrate being 15.5% (as Figures 7-8 shown). The three-stage flotation machine of the present invention realizes a strong and fast flotation recovery ability for fine-grained minerals and conventional-sized particles by dividing the flotation cell into a lower high-turbulence chamber, a middle medium-turbulence chamber, and an upper low-turbulence foam separation zone. The three-stage flotation machine in the present invention can not only efficiently recover fine particles, but also reduce the shedding of conventional-sized particles (20 - 120 microns). Therefore, the recovery rates of fine particles and conventional-sized particles are improved. At the same time, with the help of the inner cavity structure in the high-turbulence chamber of the present invention, air is transmitted by the hollow rotating shaft to the lower part of the high-turbulence chamber, and tiny bubbles are formed by the strong stirring and shearing of multiple rotor-stators in the high-turbulence chamber, increasing the collision probability between the bubbles and the fine particles. Due to the increase in the collision rate and the characteristic that fine particles are more likely to adhere to micro-bubbles, not only can the recovery rate of fine particles be improved, but also the residence time can be shortened and the throughput can be increased.

[0038] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments; any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings of the specification and above; however, any minor changes, modifications, and equivalent variations made by those skilled in the art within the scope of the technical solution of the present invention using the technical content disclosed above are equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and variations made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A three-stage flotation machine suitable for efficient sorting of wide particle sizes, comprising a flotation cell, a concentrate tank and a tailings discharge bin, wherein the concentrate tank is communicated with the upper end of the flotation cell, and is characterized in that: The flotation cell includes a high-turbulence chamber located at the lower part of the flotation cell, a medium-turbulence chamber located in the middle of the flotation cell, and a low-turbulence foam separation zone located at the upper part of the flotation cell. The high-turbulence chamber is located in the sinking area at the bottom of the flotation cell. A high-turbulence bubble mineralization mechanism is arranged in the high-turbulence chamber. The medium-turbulence chamber is located above the high-turbulence chamber, and a medium-turbulence bubble mineralization mechanism is arranged in the medium-turbulence chamber. The high-turbulence chamber is used for recovering minerals with ultra-fine particle sizes in the pulp. The medium-turbulence chamber is used for recovering minerals with conventional fine particle sizes in the pulp. The low-turbulence foam separation zone is used for separating and recovering mineral foam. The tailing discharge bin is communicated with the side wall at the lower end of the medium-turbulence chamber.

2. The three-stage flotation machine suitable for efficient sorting of wide particle size ranges according to claim 1, characterized in that: A high-turbulence bubble mineralization mechanism is arranged in the high-turbulence chamber. The medium-turbulence chamber is located above the high-turbulence chamber, and a medium-turbulence bubble mineralization mechanism is arranged in the medium-turbulence chamber. An overflow weir is arranged in the low-turbulence foam separation zone.

3. The three-stage flotation machine suitable for efficient sorting of wide particle sizes according to claim 2, wherein: The medium-turbulence bubble mineralization mechanism includes a low-damping directly-suspended stator and an impeller. The low-turbulence foam separation zone is a foam enrichment area.

4. The three-stage flotation machine suitable for efficient sorting of wide particle size ranges according to claim 2, wherein: The high-turbulence bubble mineralization mechanism includes a multi-stage series rotor-stator structure, an adjustable axial sliding coupling, and a variable-frequency motor for driving the rotation of a hollow shaft. The adjustable axial sliding coupling is used to adjust the height of the multi-stage rotor, and further adjust the size of the gap between the multi-stage rotor and the stator to achieve the adjustment of the turbulence intensity. The rotor includes a hollow shaft inserted into the high-turbulence chamber and a plurality of rotor plates arranged on the hollow shaft. The stator includes a plurality of stator plates arranged on the inner wall of the high-turbulence chamber. The stator plates and the rotor plates are of an interlocking structure. During the rotation of the rotor plates relative to the stator plates, there is always a gap for the pulp to pass through between them.

5. The three-stage flotation machine suitable for efficient sorting of wide particle size ranges according to claim 4, wherein: A plurality of rotor plates in the high-turbulence chamber are radially distributed around the hollow shaft. A plurality of stator plates are evenly spaced along the circumferential direction of the inner wall of the high-turbulence chamber, and the stator plates and the rotor plates are staggered in the vertical direction.

6. The three-stage flotation machine for efficient sorting according to claim 5, characterized in that: The rotor plates and the stator plates are respectively arranged at intervals to form convex parts and concave parts. The rotor convex parts, stator convex parts, rotor concave parts, and stator concave parts are of a trapezoidal structure, and a plurality of rotor plates and stator plates are of a hollow structure, and the hollow structure is similar to the shape of "mouth".

7. The three-stage flotation machine for efficient sorting according to claim 3, characterized in that: The low-damping directly-suspended stator is a radially short blade. The impeller is located inside the low-damping directly-suspended stator, and the installation position of the impeller is lower than that of the low-damping directly-suspended stator.

8. The three-stage flotation machine for efficient sorting according to claim 4, characterized in that: The fixed end of the adjustable axial sliding coupling is connected to the output shaft of the variable-frequency motor, and the sliding end is connected to the top end of the hollow shaft. The cavity inside the hollow shaft forms an air inlet chamber, and the air intake amount is controlled by an air intake mechanism. The air intake mechanism includes a gas flow meter, an air intake valve, a controller, a high-pressure tank, and an air compressor.

9. The three-stage flotation machine suitable for efficient sorting of wide particle size ranges according to claim 8, wherein: The upper end of the air inlet chamber is communicated with the air intake mechanism, and the lower end is communicated to the lower part of the high-turbulence chamber. The side and bottom of the lower end of the air inlet chamber are provided with air outlet openings. A feed inlet is arranged at the bottom of the lowest end of the high-turbulence chamber, and a controllable valve is arranged at the feed inlet. The controllable valve is used to adjust the feeding speed of the flotation machine.

10. The three-stage flotation machine suitable for high-efficiency sorting of wide particle size ranges according to claim 2, characterized in that: A shower water device is arranged above the flotation cell, which can reduce the gangue entrainment in the concentrate foam to improve the concentrate grade, and wash the foam from the concentrate tank to the concentrate outlet.

Images