A two-stage flotation device and method suitable for fine-grained mineral separation

Abstract

The present invention relates to a two-stage flotation device and method suitable for fine-grained mineral separation, belonging to the technical field of mineral separation and processing, and solves the problems of long flotation process flow, large floor area or low flotation efficiency in the existing fine-grained mineral recovery in the prior art. The present invention includes an outer cylinder, an inner cylinder and a middling distribution ring. The inner cylinder is arranged inside the outer cylinder, and the middling distribution ring is sleeved outside the outer cylinder. A bowl-shaped collection tank is arranged at the lower end inside the outer cylinder, the lower part of the inner cylinder is located in the bowl-shaped collection tank, and the middling distribution ring connects the bowl-shaped collection tank and the inner cylinder. The present invention adopts an inner and outer nested double-column body, which has a lower height, a small space occupation, a short flotation process, a fast flotation rate, and a physical separation between the turbulent collision area and the static separation area, and can provide high turbulence required for mineral particles to collide with bubbles and meet the static environment required for the separation of mineralized particles in a small space.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral separation and processing, and in particular to a two-stage flotation device and method suitable for fine-grained mineral separation. Background Art

[0002] With the increasing demand for coal resources by humans, high-quality coal resources are gradually exhausted, and the development and utilization of low-quality coal characterized by "poor, fine, and miscellaneous" is of great significance. However, valuable components in low-quality ores are mostly embedded in the raw ore in fine-grained form, and the raw ore needs to be ground to extremely fine particle size for full dissociation. After dissociation, fine-grained minerals / coal (diameter < 20 μm) need to be floated to separate valuable minerals from useless gangue.

[0003] However, fine-grained minerals / coal have the characteristics of low kinetic energy and small inertial force, and it is extremely difficult for conventional flotation equipment to make bubbles collide and adhere to mineral particles and complete recovery. In flotation, the fluid environment is extremely complex. High-intensity turbulence can transfer more energy to particles, increasing the probability of particle collision and adhesion, and thus improving the flotation effect. At the same time, high-intensity turbulence increases the probability of particle desorption, deteriorating the flotation effect. Conventional flotation equipment does not separately set the collision zone and the separation zone, resulting in low recovery efficiency for ultra-fine particles.

[0004] The ideal separation condition is to divide flotation into two regions: dynamic collision and static separation, and at the same time, the two regions are physically isolated. The existing cyclone-static flotation column has a good recovery effect for fine particle flotation. Pipe flow flotation generates turbulence to improve the particle-bubble collision efficiency, and then through cyclone flotation and countercurrent flotation, the concentrate flows into the concentrate tank. However, the entire flotation process has a long flow path, a large floor area, and low flotation efficiency. Summary of the Invention

[0005] In view of the above analysis, embodiments of the present invention aim to provide a two-stage flotation device and method suitable for fine-grained mineral separation to solve the problems of long flow path, large floor area, or low flotation efficiency in the existing fine-grained mineral / coal recovery flotation process.

[0006] On the one hand, the present invention provides a two-stage flotation device suitable for fine-grained mineral separation, including an outer cylinder, an inner cylinder, and a middling distribution ring. The inner cylinder is arranged inside the outer cylinder, and the middling distribution ring is sleeved outside the outer cylinder. A bowl-shaped collection tank is arranged at the lower end inside the outer cylinder, the lower part of the inner cylinder is located in the bowl-shaped collection tank, and the middling distribution ring connects the bowl-shaped collection tank and the inner cylinder.

[0007] Further, it further includes a pipe flow mineralization structure and a confrontation jet pipe. The discharge port of the middling distribution ring is connected to the feed port of the pipe flow mineralization structure, and the discharge port of the pipe flow mineralization structure is connected to the feed end of the confrontation jet pipe.

[0008] Further, the jet orifice of the confrontation jet pipe sequentially passes through the barrel walls of the outer barrel and the inner barrel and enters the inner barrel.

[0009] Further, the number of the pipe flow mineralization structures and the confrontation jet pipes is equal to the number of the discharge ports.

[0010] Further, a plurality of confrontation jet pipes are provided, and the jet orifices of the plurality of confrontation jet pipes are oppositely arranged in the inner barrel.

[0011] Further, a plurality of filling sieve plates are arranged in the outer barrel, and the filling sieve plates are located between the outer barrel and the inner barrel.

[0012] Further, a clean coal collecting tank is arranged at the upper end opening of the outer barrel.

[0013] Further, a spraying device is arranged at the upper end of the outer barrel.

[0014] Further, a middling ore outlet pipe is arranged at the bottom of the bowl-shaped collecting tank, the middling ore outlet pipe is communicated with the circulating middling ore inlet of the middling ore distribution ring through a middling ore circulating pump, and a tailing ore outlet pipe is arranged on the bottom side wall of the outer barrel.

[0015] On the other hand, the present invention provides a two-stage flotation method suitable for fine-grained mineral separation, and flotation is carried out by using the above-mentioned two-stage flotation device suitable for fine-grained mineral separation.

[0016] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects:

[0017] (1) The flotation column of the present invention adopts an inner and outer nested double-column structure, has a lower height, occupies a small space, has a short flotation process, a fast flotation rate, and a larger unit volume throughput than a traditional flotation column; by means of the double-column structure, physical separation of the turbulent collision zone and the static separation zone is realized, and high turbulence required for mineral particles to collide with bubbles can be provided in a small space, and a static environment required for separation of mineralized particles can be satisfied.

[0018] (2) The pipe flow mineralization and confrontation jet mineralization of the present invention can greatly increase the collision probability of ultra-fine particles and bubbles twice, and a higher recovery rate can be obtained for the flotation of ultra-fine-grained minerals compared with traditional flotation equipment. After adding a flushing water device, the gangue mineral entrainment in the concentrate can be effectively reduced, and the quality of the concentrate can be improved.

[0019] (3) The present invention provides a multi-layer energy dissipation cone, baffles with different shapes, and a multi-layer filling sieve plate to reduce the turbulence of the pulp in a short time, ensure stable flow, provide a stable flotation environment required for static separation, and reduce the probability of detachment of ore particles / coal from bubbles. The gear-shaped baffle can, on the one hand, provide upward turning flow to intensify the energy dissipation of the pulp; on the other hand, it can prevent the "short circuit" of the pulp and reduce the pressure of the middlings circulating pump.

[0020] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification. Moreover, some advantages can be made obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained from the content specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation of the present invention. Throughout the drawings, the same reference signs represent the same components.

[0022] Figure 1 Schematic structural diagram of a two-stage flotation device for a specific embodiment;

[0023] Figure 2 Schematic diagram of the flow direction of the middlings in the two-stage flotation device for a specific embodiment;

[0024] Figure 3 Schematic diagram of the flow directions of the concentrate and tailings in the two-stage flotation device for a specific embodiment;

[0025] Figure 4 Schematic diagram of the layout of the energy dissipation cone in the inner cylinder for a specific embodiment;

[0026] Figure 5 Schematic structural diagram of the gear-shaped baffle for a specific embodiment;

[0027] Figure 6 For a specific embodiment of Figure 1 A-A cross-sectional view;

[0028] Figure 7 Schematic connection structure diagram of a partial pipe flow mineralization structure and a confrontation jet pipe for a specific embodiment;

[0029] Figure 8 For a specific embodiment of Figure 1 B-B cross-sectional view.

[0030] Reference Signs:

[0031] 100-outer cylinder; 101-clean coal collecting tank; 102-concentrate outlet; 103-feeding pipe; 104-foam layer; 105-spraying device; 106-bowl-shaped collecting tank; 107-mid-ore outlet pipe; 108-tailings outlet pipe; 109-filling sieve plate; 110-static separation zone;

[0032] 200-inner cylinder; 201-energy dissipation cone; 202-gear-shaped baffle; 203-solid disk; 204-baffle teeth; 205-trumpet-shaped baffle; 206-turbulent collision zone; 207-energy dissipation zone;

[0033] 300 - middling ore distribution ring; 301 - discharge port; 302 - gas delivery pipe; 303 - bubble generator; 304 - flow control valve; 305 - opposing jet pipe; 306 - circulating middling ore inlet. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings 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 used to limit the scope of the present invention.

[0035] Example 1

[0036] A specific embodiment of the present invention, as Figure 1 , Figure 2 and Figure 3 As shown, a two-stage flotation device suitable for fine-grained mineral separation (hereinafter referred to as the two-stage flotation device) is disclosed, comprising an outer cylinder 100 and an inner cylinder 200 which are nested inside and outside, and the inner cylinder 200 is completely located inside the outer cylinder 100. It should be noted that in this embodiment, fine-grained minerals refer to minerals with a diameter of less than 20 μm.

[0037] Compared with the prior art, the two-stage flotation device provided in this embodiment adopts a double-layer cylinder nested inside and outside, and the inner cylinder is completely located in the outer cylinder, with a low height, small space occupation, short flotation process, fast flotation rate, and larger unit volume processing capacity than traditional flotation columns; with the help of the double-layer cylinder structure, the physical separation of the turbulent collision zone and the static separation zone is achieved, and in a small space, it can provide the high turbulence required for the collision of mineral particles with bubbles, and meet the static environment required for the sorting of mineralized particles.

[0038] Considering the collection of clean coal, the upper end of the outer cylinder 100 is open, and a clean coal collecting tank 101 is provided at the upper end opening. The clean coal collecting tank 101 surrounds the upper end of the outer cylinder 100, and a concentrate discharge port 102 is provided on the clean coal collecting tank 101. In this embodiment, the clean coal collecting tank 101 is provided at the top of the outer cylinder 100, and the clean coal flotated enters the clean coal collecting tank 101 and is discharged from the concentrate discharge port 102.

[0039] In order to facilitate the injection of incoming materials into the interior of the outer cylinder 100, a feed pipe 103 is provided at the upper opening of the outer cylinder 100. The feed pipe 103 vertically enters the foam layer 104 inside the outer cylinder 100 from the top of the outer cylinder 100. It should be noted that the incoming material of the feed pipe 103 in this embodiment is a mixture of pulp and reagent.

[0040] In order to desorb the fine mud in the foam layer 104, a spraying device 105 is also provided at the upper end of the outer cylinder 100.

[0041] A bowl-shaped collecting trough 106 is provided at the lower end inside the outer cylinder 100. The opening of the bowl-shaped collecting trough 106 faces upward, and the lower part of the inner cylinder 200 is located inside the bowl-shaped collecting trough 106. The ratio of the diameter of the bowl-shaped collecting trough 106 to the outer diameter of the outer cylinder 100 is 1 / 2 to 7 / 8, preferably 4 / 5.

[0042] A middlings outlet pipe 107 is provided at the bottom of the bowl-shaped collecting trough 106, and the middlings outlet pipe 107 passes through the bottom of the outer cylinder 100. Considering the discharge of tailings, a tailings outlet pipe 108 is provided on the bottom side wall of the outer cylinder 100.

[0043] In order to reduce the turbulence of the pulp, as Figure 1 shown, a filling sieve plate 109 is also provided inside the outer cylinder 100. The filling sieve plate 109 has multiple layers, and the filling sieve plate 109 is located between the outer cylinder 100 and the inner cylinder 200. The number of layers of the filling sieve plate 109 is 7 to 14 layers, preferably 9 layers. The sieve hole shapes of the filling sieve plate 109 include but are not limited to structures such as circular, rectangular, trapezoidal, triangular, and regular polygon.

[0044] It should be noted that the upper end of the outer cylinder 100 in this embodiment is open and the lower end is closed; the lower end of the inner cylinder 200 is open and the upper end is closed.

[0045] In order to consume energy for the pulp, as Figures 1 - 4 shown, an energy dissipation cone 201 is provided inside the inner cylinder 200. The cross-section of the energy dissipation cone 201 is triangular. The energy dissipation cone 201 has multiple layers inside the inner cylinder 200, and the energy dissipation cones 201 are distributed in a staggered manner up and down. It should be noted that the direction perpendicular to the length direction of the energy dissipation cone 201 is the transverse direction.

[0046] The number of layers of the energy dissipation cone 201 is 2 to 5 layers, preferably 3 layers. The number of energy dissipation cones 201 in each layer is 3 to 6, preferably 4.

[0047] It can be understood that the energy dissipation cone 201 has a triangular prism structure and is horizontally arranged inside the inner cylinder 200. The two ends of the energy dissipation cone 201 are connected to the inner wall of the inner cylinder 200.

[0048] In order to fully consume the energy of the pulp, the two sides of the energy dissipation cone 201 collide with the pulp to consume energy, and the other side is horizontally arranged. For the convenience of description, the three sides of the energy dissipation cone 201 are respectively denoted as the first side, the second side, and the third side. The first side is horizontally arranged, the second side and the third side are inclined, and the edge opposite to the first side faces the gap formed by two adjacent upper energy dissipation cones 201.

[0049] When the pulp in the inner cylinder 200 falls from top to bottom, the pulp that collides with the first layer of energy dissipation cones 201 undergoes one energy consumption. The pulp that directly falls through the gap between two adjacent energy dissipation cones 201 in the first layer will collide with the second layer of energy dissipation cones 201 for one energy consumption. The pulp that falls through the gap formed by the first layer of energy dissipation cones 201 after energy consumption in the first layer of energy dissipation cones 201 will collide with the second layer of energy dissipation cones 201 for another energy consumption, and so on. The pulp in the inner cylinder 200 will consume energy after passing through multiple layers of energy dissipation cones 201 from top to bottom, which can effectively reduce the pulp turbulence, ensure stable flow, and reduce the probability of detachment of ore particles and bubbles.

[0050] In this embodiment, multiple layers of triangular prism-shaped energy dissipation cones 201 are arranged in the inner cylinder 200, and the energy dissipation cones 201 of adjacent layers are staggered. When the pulp moves downward in the inner cylinder 200 and hits the energy dissipation cones 201, under the redirecting and shearing action of multiple layers of energy dissipation cones 201, the kinetic energy of the pulp decays, which can reduce the pulp turbulence, ensure stable flow, and reduce the probability of detachment of ore particles and bubbles.

[0051] Further, in order to achieve a better energy consumption effect, the second inclined surface and / or the third inclined surface of the energy dissipation cone 201 is a stepped surface, and the stepped surface is formed by alternately connecting inclined surfaces and planes. When the pulp falls onto the stepped surface, it can obtain more collision and rebound opportunities for energy consumption.

[0052] In order to further dissipate the energy of the pulp, a gear-shaped baffle 202 is provided below the inner cylinder 200, and the gear-shaped baffle 202 is horizontally arranged in the bowl-shaped collecting groove 106.

[0053] Specifically, as Figure 5 shown, the gear-shaped baffle 202 includes a solid disk body 203 and baffle teeth 204. There are multiple baffle teeth 204, and the multiple baffle teeth 204 are evenly distributed on the edge of the solid disk body 203. The baffle teeth 204 are structures such as fan-shaped rings, rectangles, squares, triangles, or semi-circles. Preferably, the solid disk body 203 is a disk, and the baffle teeth 204 are fan-shaped rings.

[0054] In this embodiment, since the flow-blocking teeth 204 are evenly distributed on the outer periphery of the solid disk body 203, gaps are formed between adjacent flow-blocking teeth 204. The pulp falling from the inner cylinder 200 collides and dissipates energy through the energy dissipation cone 201 and then falls onto the solid disk body 203 for further collision and rebound energy dissipation. The particles that have dissipated their energy will accumulate on the solid disk body 203. Under the accumulation of subsequent pulp, the particles with relatively better floatability will rise under the drive of bubbles, and the particles with relatively poorer floatability will fall through the gaps formed between adjacent flow-blocking teeth 204..

[0055] Understandably, the gear-shaped flow-blocking plate 202 faces the lower end opening of the inner cylinder 200. The pulp falling from the upper end of the inner cylinder 200 collides with the energy dissipation cone 201 and then falls onto the gear-shaped flow-blocking plate 202 for collision and redirection energy dissipation.

[0056] In this embodiment, a gear-shaped flow-blocking plate 202 is provided below the inner cylinder 200. On the one hand, it can provide upward backflow, intensify the energy dissipation of the pulp, and thus provide a good static separation environment; on the other hand, it can prevent the pulp from "short-circuiting" and reduce the working pressure of the middlings circulating pump. It should be noted that the "short-circuiting" mentioned in this embodiment refers to the pulp falling from the inner cylinder 200 directly flowing into the middlings outlet pipe 107.

[0057] In order to further dissipate the energy of the pulp, a trumpet-shaped flow-blocking plate 205 is provided at the lower end opening of the inner cylinder 200. The trumpet-shaped flow-blocking plate 205 is a side wall in the shape of a frustum of a cone. The upper end opening of the trumpet-shaped flow-blocking plate 205 is connected to the lower end opening of the inner cylinder 200, and the diameter of the upper end opening of the trumpet-shaped flow-blocking plate 205 is equal to the outer diameter of the inner cylinder 200. The diameter of the lower end opening of the trumpet-shaped flow-blocking plate 205 is not greater than the diameter of the solid disk body 203 to prevent the pulp falling from the inner cylinder 200 from forming a "short-circuit".

[0058] Preferably, the diameter of the lower end opening of the trumpet-shaped flow-blocking plate 205 is equal to the diameter of the solid disk body 203. It should be noted that the diameter of the upper end opening of the trumpet-shaped flow-blocking plate 205 is smaller than the diameter of the lower end opening. A filling sieve plate 109 is also provided in the bowl-shaped collecting groove 106, specifically above the inner cylinder 200 and outside the trumpet-shaped flow-blocking plate 205.

[0059] In this embodiment, the pulp moving downward from the upper end of the inner cylinder 200 first hits the energy dissipation cone 201. Under the action of the multi-layer energy dissipation cone 201 for redirecting and shearing, the kinetic energy of the pulp decays. The pulp flowing downward then hits the gear-shaped baffle 202, is redirected by the solid disk 203 and then hits the horn-shaped baffle 205. After multiple impacts and redirections, the kinetic energy of the pulp is greatly reduced. The low-energy pulp is pushed by the subsequent pulp and decelerates through the multi-layer filling sieve plate 109 and then is evenly suspended in the outer cylinder 100. The energy dissipation cone 201, the gear-shaped baffle 202 and the horn-shaped baffle 205 can reduce the pulp turbulence, ensure stable flow and reduce the probability of ore particles detaching from bubbles. The gear-shaped baffle 202 can not only provide upward backflow, intensify the energy dissipation of the pulp, thereby providing a good static separation environment, but also prevent the pulp from "short-circuiting" and reduce the pressure of the middlings circulating pump.

[0060] As Figure 1 and Figure 2 shown, the two-stage flotation device further includes a middlings distribution ring 300. The middlings distribution ring 300 is sleeved outside the outer cylinder 100. The middlings distribution ring 300 is of a cylindrical structure, and its inner diameter is equal to the outer diameter of the outer cylinder 100.

[0061] Further, as Figure 6 shown, a plurality of discharge ports 301 are evenly distributed on the outer cylindrical surface of the middlings distribution ring 300. The number of the discharge ports 301 is 2 - 8, preferably 4. The 4 discharge ports 301 are arranged circumferentially on the middlings distribution ring 300 at intervals of 90°.

[0062] To achieve the primary mineralization of the pulp, the two-stage flotation device further includes a pipe-flow mineralization structure. The number of the pipe-flow mineralization structures is the same as the number of the discharge ports 301. Combining Figure 1 、 Figure 2 and Figure 7 shown, the pipe-flow mineralization structure includes a gas delivery pipe 302 and a bubble generator 303. The gas delivery pipe 302 is a corrugated pipe, and the corrugated pipe can reduce the damage to the pipeline caused by external vibration. The bubble generator 303 is a Venturi tube.

[0063] Specifically, one end of the gas delivery pipe 302 is an input end, the input end is communicated with external air, the other end is an output end, the output end is communicated with the air inlet of the bubble generator 303, and the feed inlet of the bubble generator 303 is communicated with the discharge port 301.

[0064] Considering that the pulp in the middlings distribution ring 300 will enter the gas delivery pipe 302 when the two-stage flotation device stops, in order to prevent the pulp from flowing out of the input end of the gas delivery pipe 302, the input end of the gas delivery pipe 302 is higher than the clean coal collection tank 101. Since during on-site operation, personnel stand on the upper part of the two-stage flotation device, for the convenience of personnel operation, the flow regulating valve 304 for adjusting the gas intake volume is arranged at the input end of the gas delivery pipe 302.

[0065] In order to reduce the floor area of the two-stage flotation device, the gas delivery pipe 302 is in an L shape, including a vertical section and a horizontal section. The vertical section is arranged inside the outer cylinder 100 and is connected to the inner wall of the outer cylinder 100. One end of the horizontal section passes through the side wall of the outer cylinder 100 and is connected to the vertical section, and the other end is connected to the bubble generator 303 arranged outside the outer cylinder 100.

[0066] In order to achieve secondary mineralization of the pulp, the two-stage flotation device further includes confrontation jet pipes 305, and the number of confrontation jet pipes 305 is the same as the number of pipe-flow mineralization structures. Combining Figure 1 、 Figure 2 and Figure 7 As shown, one end of the confrontation jet pipe 305 is communicated with the discharge port of the bubble generator 303, and the other end sequentially passes through the side walls of the outer cylinder 100 and the inner cylinder 200 and enters the inner cylinder 200. That is, the feed port of the confrontation jet pipe 305 is communicated with the discharge port of the bubble generator 303, and the jet ports of the confrontation jet pipe 305 are located inside the inner cylinder 200. As Figure 8 shown, the jet ports are arranged opposite to each other inside the inner cylinder 200, that is, in a confrontation state.

[0067] In order to achieve the circulation of the middlings, a circulating middlings inlet 306 is opened on the side wall of the middlings distribution ring 300. The circulating middlings inlet 306 is communicated with the middlings outlet pipe 107 through a pipeline, and a middlings circulation pump (not shown in the figure) is arranged in the pipeline.

[0068] It should be noted that the upper end inside the outer cylinder 100 (the clean coal collection tank 101 area) is the foam layer 104, below the foam layer 104 is the static separation area 110, the upper end inside the inner cylinder 200 (the confrontation jet area) is the turbulent collision area 206, and below the turbulent collision area 206 is the energy dissipation area 207.

[0069] Embodiment 2

[0070] Another specific embodiment of the present invention, as Figures 1 - 8 shown, discloses a two-stage flotation method suitable for fine-grained mineral separation. Using the two-stage flotation device suitable for fine-grained mineral separation in Embodiment 1, the steps include:

[0071] Step S1: Inject the floated ore pulp into the outer cylinder 100 to a height of 1 / 2 of the outer cylinder 100.

[0072] In this step, the floated ore pulp is injected into the outer cylinder 100 through the feed pipe 103, and the tailings outlet pipe 108 and the middlings outlet pipe 107 at the bottom of the bowl-shaped collecting tank 106 are in a closed state.

[0073] Step S2: Pump the pulp in the bowl-shaped collecting tank 106 into the middlings distribution ring 300 through the middlings circulation pump, and the pulp is fed into the pipe flow mineralization structure through the middlings distribution ring 300 for primary mineralization.

[0074] Specifically, the middlings outlet pipe 107 and the middlings circulation pump are opened simultaneously, and the pulp in the bowl-shaped collecting tank 106 is pumped into the middlings distribution ring 300 through the middlings circulation pump; the pulp enters the pipe flow mineralization structure through the discharge port 301 of the middlings distribution ring 300, and high-speed flow generates negative pressure to introduce external air into the pipe; the high-speed circulating pulp in the pipe shears the air to generate bubbles and is fully mixed with the pulp to complete primary mineralization, and then enters the confrontation jet pipe 305 under the push of the subsequent pulp. The air volume entering the pipe flow mineralization structure is controlled by adjusting the opening of the flow regulating valve 304.

[0075] Step S3: The pulp after primary mineralization enters the inner cylinder 200 through the stepped jet orifice at the end of the confrontation jet pipe 305, and collides and mixes with the pulp coming out of other jet orifices to complete secondary mineralization.

[0076] Step S4: The pulp after two-stage mineralization dissipates energy through the energy dissipation cone 201, the gear-shaped baffle 202 and the horn-shaped baffle 205, and the pulp after energy dissipation is evenly suspended in the outer cylinder 100.

[0077] Specifically, the pulp after two-stage mineralization moves downward and hits the energy dissipation cone 201; the multi-layer energy dissipation cone 201, the gear-shaped baffle 202 and the horn-shaped baffle 205 are structurally coupled to change the flow direction of the pulp, and the energy dissipation of the pulp is intensified by means of shearing and impact. Finally, after being redirected and decelerated by the bowl-shaped collecting tank 106 and the multi-layer filling sieve plate 109, it is evenly suspended and distributed in the outer cylinder 100.

[0078] Step S5: The tailings outlet pipe 108 discharges the tailings product, the bowl-shaped collecting tank 106 contains the circulating middlings, and the concentrate discharge port 102 discharges the concentrate product.

[0079] Specifically, after a foam layer 104 is formed above the outer cylinder 100, the tailings outlet pipe 108 is opened. At this time, the pulp is directly fed into the foam layer 104 through the feed pipe 103. The mineral particles with better floatability in the fed pulp stay in the foam layer 104, and the gangue with poorer floatability falls through the foam layer 104 and enters the pulp; the mineral particles with better floatability that adhere to the bubbles in the pulp that has been mineralized twice and suspended in the outer cylinder 100 float up to the foam layer 104; a small part of the minerals that do not enter the foam layer 104 and the minerals in the feed that pass through the foam layer 104 and enter the pulp fall to the bottom of the outer cylinder 100 under the action of gravity and finally are discharged through the tailings outlet pipe 108 to become tailings, and most of them fall into the bowl-shaped collecting tank 106 to become recycled middlings.

[0080] The particles staying in the foam layer 104 in the feed and the particles entering the foam layer 104 from the pulp are suspended upward and, under the action of the spray water sprayed by the spraying device 105, the fine mud in the foam layer 104 is desorbed. The concentrate foam layer formed after the desorption of the fine mud enters the concentrate collecting tank 101 under the action of overflow, and finally the concentrate product is discharged from the concentrate discharge port 102.

[0081] Step S6: Continue to float the mixture of the raw pulp and the recycled middlings.

[0082] The feed pipe 103 injects the flotation pulp (raw pulp) into the outer cylinder 100, and the raw pulp is mixed with the middlings in the outer cylinder 100 to form a mixed pulp. Steps S2 to S5 are repeated to float the mixed pulp. In this process, the pulp in Steps S2 to S5 is no longer the raw pulp, but a mixture of the raw pulp and the middlings.

[0083] It should be noted that when the two-stage flotation device performs the first flotation, the raw material for flotation is the raw pulp, and when it performs the second flotation, the raw material for flotation is a mixture of the raw pulp and the middlings.

[0084] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A two-stage flotation device suitable for fine-grained mineral separation, characterized in that, It includes an outer cylinder (100), an inner cylinder (200) and a middling distribution ring (300). The inner cylinder (200) is arranged inside the outer cylinder (100), and the middling distribution ring (300) is sleeved outside the outer cylinder (100). At the lower end inside the outer cylinder (100), there is a bowl-shaped collection trough (106). The lower part of the inner cylinder (200) is located inside the bowl-shaped collection trough (106). The middling distribution ring (300) connects the bowl-shaped collection trough (106) and the inner cylinder (200). Inside the inner cylinder (200), there is an energy dissipation cone (201). The cross-section of the energy dissipation cone (201) is triangular. There are multiple layers of the energy dissipation cone (201) arranged inside the inner cylinder (200), and the energy dissipation cones (201) are distributed in a staggered manner up and down. The energy dissipation cone (201) has a triangular prism structure and is horizontally arranged inside the inner cylinder (200). Both ends of the energy dissipation cone (201) are connected to the inner wall of the inner cylinder (200). Below the inner cylinder (200), there is a gear-shaped baffle (202). The gear-shaped baffle (202) is horizontally arranged inside the bowl-shaped collection trough (106). The gear-shaped baffle (202) includes a solid disk body (203) and baffle teeth (204). There are multiple baffle teeth (204), and the multiple baffle teeth (204) are evenly distributed on the edge of the solid disk body (203).

2. The two-stage flotation device suitable for fine-grained mineral separation according to claim 1, characterized in that It also includes a pipe-flow mineralization structure and a confrontation jet pipe (305). The discharge port (301) of the middling distribution ring (300) is communicated with the feed port of the pipe-flow mineralization structure, and the discharge port of the pipe-flow mineralization structure is communicated with the feed end of the confrontation jet pipe (305).

3. The two-stage flotation device suitable for fine-grained mineral separation according to claim 2, characterized in that The jet port of the confrontation jet pipe (305) sequentially passes through the cylinder walls of the outer cylinder (100) and the inner cylinder (200) and enters the inner cylinder (200).

4. The two-stage flotation device suitable for fine-grained mineral separation according to claim 2 or 3, characterized in that, The number of the pipe-flow mineralization structures and the confrontation jet pipes (305) is equal to the number of the discharge ports (301).

5. The two-stage flotation device suitable for fine-grained mineral separation according to claim 4, characterized in that, There are multiple confrontation jet pipes (305), and the jet ports of the multiple confrontation jet pipes (305) are arranged oppositely inside the inner cylinder (200).

6. The two-stage flotation device suitable for fine-grained mineral separation according to any one of claims 1-3 and 5, characterized in that Inside the outer cylinder (100), there are multiple layers of filling sieve plates (109). The filling sieve plates (109) are located between the outer cylinder (100) and the inner cylinder (200).

7. The two-stage flotation device suitable for fine-grained mineral separation according to any one of claims 1-3 and 5, characterized in that, At the upper opening of the outer cylinder (100), there is a clean coal collection trough (101).

8. The two-stage flotation device suitable for fine-grained mineral separation according to any one of claims 1-3 and 5, characterized in that At the upper end of the outer cylinder (100), there is a spraying device (105).

9. The two-stage flotation device suitable for fine-grained mineral separation according to any one of claims 1-3 and 5, characterized in that, At the bottom of the bowl-shaped collection trough (106), there is a middling outlet pipe (107). The middling outlet pipe (107) is connected to the circulating middling inlet (306) of the middling distribution ring (300) through a middling circulating pump. On the bottom side wall of the outer cylinder (100), there is a tailing outlet pipe (108).

10. A two-stage flotation method suitable for fine-grained mineral separation, characterized in that, Floatation is carried out by using the two-stage floatation device for fine-grained mineral separation according to any one of claims 1-9.

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