Method for producing aluminum fluoride from fluorite tailings waste

Abstract

The application discloses a fluorite tailing waste residue production method of aluminum fluoride, and relates to the technical field of aluminum fluoride production processes. The fluorite tailing waste residue production method of aluminum fluoride comprises the following steps: step one, mixing the purified fluorite tailing and concentrated sulfuric acid according to a proportion, and heating and reacting in a rotary kiln to generate hydrogen fluoride gas; and step two, passing the hydrogen fluoride gas into a fluidized bed, and fluidizing and reacting the hydrogen fluoride gas in the fluidized bed in a posture of rotating around an aluminum hydroxide bed layer, and driving the aluminum hydroxide bed layer to tumble under the flow of the hydrogen fluoride gas. Through the driving of a rotating assembly in the fluidized bed, the hydrogen fluoride gas is driven to rotate around the aluminum hydroxide bed layer for fluidization and combination reaction, so that the hydrogen fluoride gas always passes through the aluminum hydroxide bed with uniform thickness, and the hydrogen fluoride gas acts on the uniform tumbling fluidization reaction of the aluminum hydroxide bed layer.

Description

Technical Field

[0001] This invention relates to the field of aluminum fluoride production technology, specifically a method for producing aluminum fluoride from fluorite tailings waste. Background Technology

[0002] The technology for producing aluminum fluoride from fluorite tailings is an important direction for realizing tailings resource utilization and reducing solid waste pollution. Currently, the mainstream industrial processes for producing aluminum fluoride are the "wet process" and the "dry process". In the dry process, powdered aluminum hydroxide and hydrogen fluoride gas are fully mixed and reacted at a temperature of 500-600°C. The aluminum hydroxide is dehydrated by heating to form aluminum oxide, which then reacts with hydrogen fluoride.

[0003] For example, Chinese patent CN120157163A discloses a process and system for producing aluminum fluoride using a dry process with low-grade fluorite. In this process, purified hydrogen fluoride gas and dried aluminum hydroxide are added to a fluidized bed for reaction. At this time, aluminum hydroxide is transported from the aluminum hydroxide silo to the top bed to react with hydrogen fluoride gas. The aluminum hydroxide in the top bed enters the bottom bed through the overflow pipe to continue reacting with hydrogen fluoride gas, so that the hydrogen fluoride gas passes through the dynamically flowing double-layer fluidized bed for fluidization reaction.

[0004] In a fluidized bed reactor, when hydrogen fluoride gas flows upward from the bottom of the reactor, at low flow rates, the gas only passes through the gaps between particles, and the particles remain stationary (fixed bed state). As the flow rate increases, the upward drag and buoyancy of the gas on the particles gradually increase. When the flow rate reaches the critical fluidization velocity, the drag force plus buoyancy is exactly equal to the particle weight, and the particles begin to break free from the fixed state, exhibiting a tumbling fluidized state. If the flow rate continues to increase to the carry-out velocity, the particles will be entrained by the gas and fly out of the reactor. Therefore, the flow rate of hydrogen fluoride gas and the fluidization state of aluminum hydroxide determine its fluidization reaction performance. However, in existing forms of fluidized reactions, due to the dynamic flow characteristics of aluminum hydroxide, the bed thickness often cannot be kept uniform. When the aluminum hydroxide bed is thick, the hydrogen fluoride gas throughput is low; when the aluminum hydroxide bed is thin, aluminum hydroxide particles are easily entrained and carried away by hydrogen fluoride gas, causing the bed to be "permeable," resulting in incomplete fluidization reaction and low binding reaction efficiency of hydrogen fluoride gas during the fluidization reaction process. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for producing aluminum fluoride from fluorite tailings slag, thus solving the problems mentioned in the background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for producing aluminum fluoride from fluorite tailings waste, comprising the following steps:

[0007] Step 1: Mix the purified fluorite tailings with concentrated sulfuric acid in a certain proportion, and heat the mixture in a rotary kiln to generate hydrogen fluoride gas.

[0008] Step 2: Hydrogen fluoride gas is introduced into the fluidized bed. The hydrogen fluoride gas in the fluidized bed undergoes a fluidization reaction in a rotating manner around the aluminum hydroxide bed, and the flow of hydrogen fluoride gas drives the aluminum hydroxide bed to tumble.

[0009] Step 3: After the fluidization reaction, the hydrogen fluoride gas is discharged from the fluidized bed, and the aluminum hydroxide bed that has been fluidized and tumbled is re-laid to form a uniform and flat aluminum hydroxide bed again, so as to continue the fluidization reaction in a uniform manner and finally produce aluminum fluoride.

[0010] Furthermore, the fluidized bed is equipped with a rotating assembly, wherein the rotating assembly includes: a distribution plate located inside the fluidized bed, the distribution plate forming a split-type arrangement of fluidizing chambers for laying the aluminum hydroxide bed layer; a second turntable located below the fluidizing chambers, with an air inlet channel on its surface; and a first turntable located above the fluidized chambers, with an exhaust channel on its surface; the air inlet channel and the exhaust channel form a hydrogen fluoride gas delivery channel, allowing the hydrogen fluoride gas to rotate and fluidize around the aluminum hydroxide bed layer.

[0011] Furthermore, the rotating assembly also includes: an opening and closing flap, which is rotatably installed in a split configuration at the bottom of each fluidization chamber; and a fixed sleeve, which is rotatably installed in the middle of the distribution plate, wherein the middle of the fixed sleeve forms a transmission track, a first sector rack is provided on one side of the transmission track, and a second sector rack is provided on the other side of the transmission track; the fluidization chamber is provided with a rotating shaft that provides the opening and closing flap for swaying rotation, and a first sector gear is provided at one end of the rotating shaft, so that when the first sector rack and the second sector rack pass through the first sector gear, they are used to sway the opening and closing flap for unloading the aluminum hydroxide bed after fluidization reaction in the fluidization chamber.

[0012] Furthermore, the rotating assembly also includes: a discharge channel located below the swing path of the opening and closing flap; and a material spreading pipe located on one side above the swing path of the opening and closing flap, and offset from the discharge channel; the discharge channel and the material spreading pipe form an aluminum hydroxide bed conveying channel, so that the aluminum hydroxide bed after fluidization and tumbling is discharged and re-laid in the fluidization chamber.

[0013] Furthermore, a conveying shaft is provided in the middle of the inner side of the fluidized bed. The conveying shaft is fixedly connected to the fixed sleeve and is used for the circumferential rotation reaction of hydrogen fluoride gas around the aluminum hydroxide bed and for the unloading of the aluminum hydroxide bed after fluidization and tumbling. A spiral auger is rotatably installed inside the conveying shaft for the return laying of the aluminum hydroxide bed after unloading.

[0014] Furthermore, the material spreading pipe is equipped with a pushing and crushing structure. This structure responds to the rotational drive of the rotating component and is used for crushing and spreading aluminum hydroxide particles back into the material spreading pipe. The pushing and crushing structure includes: a conveyor belt, installed within the material spreading pipe and spaced apart to form a circulation chamber; a sieve plate at the bottom of the circulation chamber for screening aluminum hydroxide particles during the crushing process; blades, arranged symmetrically in pairs within the circulation chamber, with at least one set; the blades are rotatably mounted on the conveyor belt, and a second sector gear is located at one end of each blade; and a sector toothed belt, installed within the rotational trajectory of the conveyor belt and meshing with the second sector gear. This allows the blades to dynamically transform from push plates to paddles when the conveyor belt pushes them along the circulation chamber, for pushing and crushing the aluminum hydroxide bed within the circulation chamber.

[0015] Furthermore, the material pushing and crushing structure also includes: a toothed ring arranged on the rotation path of the material spreading pipe; a toothed belt arranged on the inner ring of the conveyor belt, and at least one set thereof; and two sets of drive shafts arranged at both ends of the conveyor belt, with drive pulleys meshing with the toothed belts on the axial direction of the drive shafts. One end of one set of drive shafts is provided with a gear pair meshing with the toothed ring to generate driving force for the conveyor belt.

[0016] Furthermore, the opening and closing flap is a fan-shaped mesh structure, the unloading channel is a fan-shaped frame structure, the unloading channel and the opening and closing flap are coaxial, and the unloading opening of the unloading channel is larger than the plate surface of the opening and closing flap.

[0017] Furthermore, the first turntable has a first heating coil on its surface, and the second turntable has a second heating coil on its surface.

[0018] Furthermore, a first rotating channel is provided on one side of the rotation path of the air intake channel, wherein the first rotating channel is conductively connected to the air intake channel; a second rotating channel is provided on one side of the rotation path of the exhaust channel, wherein the second rotating channel is conductively connected to the exhaust channel.

[0019] The present invention has the following beneficial effects:

[0020] (1) In the method for producing aluminum fluoride from fluorite tailings, when hydrogen fluoride gas is introduced into the fluidized bed, the rotating components in the fluidized bed drive the hydrogen fluoride gas to rotate around the aluminum hydroxide bed to carry out the fluidization reaction, so that the hydrogen fluoride gas always passes through the aluminum hydroxide bed with uniform thickness and acts on the uniform rolling fluidization reaction of the aluminum hydroxide bed, thereby improving the stability and comprehensiveness of the reaction between hydrogen fluoride gas and aluminum hydroxide bed.

[0021] (2) The method for producing aluminum fluoride from fluorite tailings waste, through the setting of the rotating component, can promote the hydrogen fluoride gas to rotate and fluidize around the aluminum hydroxide bed, and at the same time, can also re-lay the fluidized and rolled aluminum hydroxide bed to form a uniformly flat aluminum hydroxide bed again, which prepares for the continuous circumferential rotation reaction of hydrogen fluoride, so that the fluidized combination reaction of hydrogen fluoride gas and aluminum hydroxide bed is always in a uniform dynamic combination.

[0022] (3) In the method of producing aluminum fluoride from fluorite tailings slag, when the rotating component acts on the circulating material of the aluminum hydroxide bed, the setting of the pushing and crushing structure can not only spread and unload the aluminum hydroxide bed when it is re-laid, but also pre-crush the aluminum hydroxide particles, reduce the "agglomeration" phenomenon that occurs in the aluminum hydroxide bed during the accumulation process, and improve the fullness of the combination reaction between hydrogen fluoride gas and aluminum hydroxide bed.

[0023] (4) The method for producing aluminum fluoride from fluorite tailings waste can rearrange the particles inside the aluminum hydroxide bed by rotating the component to re-lay the aluminum hydroxide bed. At this time, the heating coils set above and below the aluminum hydroxide bed can be used to heat the aluminum hydroxide bed in real time, ensuring the consistency of the reaction temperature inside and outside the aluminum hydroxide bed, avoiding uneven temperature, which would lead to insufficient reaction conversion rate and a surge in energy consumption.

[0024] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0025] Figure 1 This is a process flow diagram of the present invention;

[0026] Figure 2 This is a schematic diagram of the first structure of the fluidized bed in this invention;

[0027] Figure 3 This is a schematic diagram of the second structure of the fluidized bed in this invention;

[0028] Figure 4 This is a first assembly diagram of the rotating component in this invention;

[0029] Figure 5 This is a second assembly diagram of the rotating component in this invention;

[0030] Figure 6 This is a partial cross-sectional view of the rotating component in this invention;

[0031] Figure 7 This is a schematic diagram of the driving mechanism of the rotating component in this invention;

[0032] Figure 8This is a schematic diagram of the first flow path of hydrogen fluoride gas in this invention;

[0033] Figure 9 This is a schematic diagram of the second flow path of hydrogen fluoride gas in this invention;

[0034] Figure 10 This is a schematic diagram showing the arrangement of the opening and closing flaps in this invention;

[0035] Figure 11 This is a schematic diagram of the opening and closing of the flap in this invention;

[0036] Figure 12 This is a schematic diagram of the drive mechanism for opening and closing the flap in this invention;

[0037] Figure 13 This is a schematic diagram of the first unloading of the aluminum hydroxide bed in this invention;

[0038] Figure 14 This is a schematic diagram of the second unloading of the aluminum hydroxide bed in this invention;

[0039] Figure 15 This is a first assembly schematic diagram of the feeding and crushing structure in this invention;

[0040] Figure 16 This is a second assembly schematic diagram of the feeding and crushing structure in this invention;

[0041] Figure 17 This is a schematic diagram of the third assembly of the feeding and crushing structure in this invention;

[0042] Figure 18 This is a schematic diagram of the material laying pipe in this invention;

[0043] Figure 19 This is a first driving schematic diagram of the feeding and crushing structure in this invention;

[0044] Figure 20 This is a schematic diagram of the second drive mechanism of the feeding and crushing structure in this invention.

[0045] In the diagram, 1. Fluidized bed; 2. Air inlet; 3. Exhaust outlet; 4. Conveyor shaft; 5. Spiral auger; 6. First drive belt; 7. Second drive belt; 8. Motor; 9. Feed inlet; 10. Discharge outlet; 11. First turntable; 12. Distribution plate; 13. Second turntable; 14. First rotating channel; 15. Second rotating channel; 16. Exhaust channel; 17. Fixed sleeve; 18. Discharge pipe; 19. Material spreading pipe; 20. Gear pair; 21. Gear ring; 22. Feed inlet; 23. Discharge channel; 4. Air intake channel; 25. Opening and closing flap; 26. Transmission rail; 27. First heating coil; 28. Second heating coil; 29. ​​Rotating shaft; 30. First sector gear; 31. First sector rack; 32. Second sector rack; 33. Material spreading cone; 34. Transmission shaft; 35. Transmission pulley; 36. Transmission belt; 37. Toothed belt; 38. Blade; 39. Screen plate; 40. First limiting guide rail; 41. Second limiting guide rail; 42. Sector toothed belt; 43. Second sector gear; 44. Track groove. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0048] The following is based on Figures 1-20 This invention describes a method for producing aluminum fluoride from fluorite tailings waste.

[0049] like Figure 1 As shown, a method for producing aluminum fluoride from fluorite tailings waste includes the following steps:

[0050] Step 1: Mix the purified fluorite tailings with concentrated sulfuric acid in a certain proportion, and heat the mixture in a rotary kiln to generate hydrogen fluoride gas.

[0051] Step 2: Hydrogen fluoride gas is introduced into fluidized bed 1. The hydrogen fluoride gas in fluidized bed 1 undergoes a fluidization reaction in a rotating manner around the aluminum hydroxide bed, and the aluminum hydroxide bed is driven to tumble by the flow of hydrogen fluoride gas.

[0052] Step 3: After the fluidization reaction, the hydrogen fluoride gas is discharged from fluidized bed 1, and the aluminum hydroxide bed layer after fluidization and tumbling is re-laid to form a uniform and flat aluminum hydroxide bed layer again, in preparation for the next fluidization.

[0053] like Figures 2-9 As shown, to achieve the fluidized bed reaction by rotating hydrogen fluoride gas around the aluminum hydroxide bed, a rotating assembly is provided in the fluidized bed 1. The rotating assembly includes a distribution plate 12 fixed within the fluidized bed 1. The distribution plate 12 forms separately arranged fluidizing chambers for laying the aluminum hydroxide bed (the fluidizing chambers are arranged in a fan-shaped, separately arranged configuration to divide the aluminum hydroxide bed into independent, uniformly laid bed structures). A second rotating plate 13 is located below the fluidizing chambers, with an inlet channel 24 on its surface. A first rotating plate 11 is located above the fluidizing chambers, with an exhaust channel 16 on its surface. The inlet channel 24 and the exhaust channel 16 form a hydrogen fluoride gas delivery channel (the inlet channel 24 and the exhaust channel 16 are aligned with each other, and their vents face the bottom and top of the fluidizing chamber, respectively). The system rotates the first and second turntables 11 and 13, causing the inlet channel 24 and exhaust channel 16 to rotate around the fluidization chamber. This allows the hydrogen fluoride gas, introduced through the inlet channel 24, to pass through the aluminum hydroxide bed in the fluidization chamber and be immediately discharged through the exhaust channel 16. Driven by rotation, the hydrogen fluoride gas sequentially undergoes a fluidization reaction with the aluminum hydroxide bed in the next fluidization chamber. Because the aluminum hydroxide bed is evenly distributed within the fluidization chamber, the rotational transport of the hydrogen fluoride gas ensures that it consistently reacts with the evenly distributed aluminum hydroxide bed, guaranteeing a sufficient fluidization reaction and preventing instability in the hydrogen fluoride gas fluidization reaction due to excessive variations in the thickness of the aluminum hydroxide bed.

[0054] As a further solution to this embodiment, such as Figures 3-4 , Figure 6 As shown, the rotating assembly also includes a fixed sleeve 17 rotatably mounted in the middle of the distributing plate 12 (the outer ring of the distributing plate 12 is fixed on the fluidized bed 1, and the inner ring is rotatably mounted on the fixed sleeve 17 to provide support for the central part). The fixed sleeve 17 is fixedly connected to the first turntable 11 and the second turntable 13 respectively. Furthermore, a conveying shaft 4 is rotatably mounted in the middle of the inner side of the fluidized bed 1. A motor 8 is provided on the fluidized bed 1, and a first transmission belt 6 is provided between the motor 8 and the conveying shaft 4. The motor 8 is used as a drive source, and the conveying shaft 4 is driven to rotate through the first transmission belt 6. The fixed sleeve 17 generates a rotational driving force acting on the first turntable 11 and the second turntable 13, so that the air inlet channel 24 and the exhaust channel 16 rotate around the aluminum hydroxide bed to carry out the dynamic fluidization reaction of hydrogen fluoride gas.

[0055] Furthermore, such as Figures 8-9 As shown, a first rotating channel 14 is provided on one side of the rotation path of the intake channel 24, and a second rotating channel 15 is provided on one side of the rotation path of the exhaust channel 16. The first rotating channel 14 and the second rotating channel 15 are respectively rotatably mounted on the fluidized bed 1, and an intake port 2 and an exhaust port 3 (e.g., [missing information]) are respectively provided on the fluidized bed 1 to communicate with the first rotating channel 14 and the second rotating channel 15. Figure 4 , Figure 5 As shown, both the first rotating channel 14 and the second rotating channel 15 are divided into inner and outer parts. The outer part is fixed and connected to the inlet 2 and the outlet 3, respectively. The inner part is rotating and connected to the inlet channel 24 and the outlet channel 16, respectively. A sealing gasket is provided between the inner and outer parts to achieve relatively sealed operation, so that the hydrogen fluoride gas before the reaction flows to the rotating inlet channel 24, and the mixed gas after the reaction is discharged from the outlet channel 16 to the outlet 3. The first rotating channel 14 is electrically connected to the inlet channel 24, and the second rotating channel 15 is electrically connected to the outlet channel 16, which is used for fluidized combination of hydrogen fluoride gas. During the reaction, hydrogen fluoride gas is transported to the first rotating channel 14 through the air inlet 2. Utilizing the rotational characteristics of the first rotating channel 14, the first rotating channel 14 rotates synchronously with the air inlet channel 24, while the hydrogen fluoride gas is continuously guided and transported into the air inlet channel 24. Simultaneously, utilizing the rotational characteristics of the second rotating channel 15, the second rotating channel 15 rotates synchronously with the exhaust channel 16, while the hydrogen fluoride waste gas discharged from the exhaust channel 16 is discharged through the exhaust port 3 into the subsequent cyclone dust collector for dust removal, providing the channel required for the dynamic transport of hydrogen fluoride gas within the aluminum hydroxide bed.

[0056] It should be noted that the first turntable 11 and the second turntable 13 are respectively attached to the upper and lower parts of the distribution plate 12 to perform deep and independent separation of the aluminum hydroxide bed in the distribution plate 12. This ensures that the aluminum hydroxide bed in each fluidization chamber of the distribution plate 12 is set independently. When hydrogen fluoride gas passes through the aluminum hydroxide bed, it only acts on the fluidization and bonding reaction of the current aluminum hydroxide bed and does not drive the fluidization and tumbling of the aluminum hydroxide bed in other fluidization chambers. This maintains the dynamic and uniform fluidization reaction between the hydrogen fluoride gas and the aluminum hydroxide bed. Furthermore, since the hydrogen fluoride gas can only pass through the corresponding aluminum hydroxide bed when it is input through the air inlet channel 24, and after the fluidization and bonding reaction, it is only discharged through the exhaust channel 16, this improves the orderly flow of hydrogen fluoride gas while avoiding large-scale diffusion of hydrogen fluoride gas, which could cause large fluctuations in air velocity and unstable fluidization and bonding reactions in the fluidized bed 1.

[0057] like Figures 5-7 , Figures 10-14As shown, to achieve uniform re-laying of the aluminum hydroxide bed after the fluidized bed reaction, the rotating assembly also includes a split-type rotating flap 25 installed at the bottom of each fluidization chamber. A rotating shaft 29 is provided within the fluidization chamber to allow the flap 25 to swing freely (the flap 25 maintains its downward swing characteristic under the rotational support of the rotating shaft 29; at this time, the second turntable 13 acts as a bottom support for the fluidization chamber, supporting the flap 25 and keeping it horizontal, thus supporting the aluminum hydroxide bed; the flap 25 can only swing when it passes through the opening on the second turntable 13, allowing for the unloading of the aluminum hydroxide bed). A first sector gear 30 is provided at one end of the rotating shaft 29, wherein a transmission track 26 is formed in the middle of the fixed sleeve 17, for transmission... A first sector rack 31 is provided on one side of the track 26, and a second sector rack 32 is provided on the other side of the transmission track 26 (the combination of the first sector rack 31 and the second sector rack 32 is located in front of the rotation path of the air intake channel 24 and maintains a sufficient distance from the air intake channel 24 to provide sufficient time for unloading and re-laying the aluminum hydroxide bed). While the conveying shaft 4 pushes the fixed sleeve 17 to rotate, it drives the transmission track 26 to rotate synchronously, so that the first sector rack 31 and the second sector rack 32 in the transmission track 26 pass through the first sector gear 30 on each opening and closing flap 25. The meshing drive of the first sector rack 31 and the second sector rack 32 on the first sector gear 30 generates a driving force that pushes the opening and closing flap 25 to rotate in an orderly manner and to reset (e.g., ...). Figures 10-12 As shown), during the opening and closing process of the flap 25, the aluminum hydroxide bed in the corresponding fluidized chamber is unloaded to the bottom of the fluidized bed 1, and after the flap 25 closes and resets, it prepares for the repaving of the aluminum hydroxide bed. Specifically:

[0058] Below the swing path of the opening and closing flap 25, there is a discharge channel 23. The discharge channel 23 is located on the second turntable 13 and close to the first sector rack 31 and the second sector rack 32. The opening and closing flap 25 is a sector mesh structure and the discharge channel 23 is a sector frame structure. The discharge channel 23 is coaxial with the opening and closing flap 25 and the discharge opening of the discharge channel 23 is larger than the plate surface of the opening and closing flap 25. When the fixed sleeve 17 drives the second turntable 13 to rotate, the discharge channel 23 simultaneously passes through the opening and closing flap 25 to be opened and closed, providing opening and closing and reset space for the opening and closing flap 25, so that the aluminum hydroxide bed in the corresponding fluidization chamber is discharged to the bottom of the fluidized bed 1 through the discharge channel 23.

[0059] As a further embodiment of this invention, a material laying pipe 19 is provided on one side above the swing path of the opening and closing flap 25. The material laying pipe 19 is located on the first turntable 11 and is offset from the unloading channel 23. The material laying pipe 19 and the unloading channel 23 form an aluminum hydroxide bed conveying channel, so that the aluminum hydroxide bed after fluidization and tumbling is unloaded and re-laid in the fluidization chamber. After the aluminum hydroxide bed is unloaded after the fluidization reaction, the aluminum hydroxide bed is conveyed to the material laying pipe 19 by the conveying action of the conveying shaft 4 and re-laid in the fluidization chamber after unloading, so as to provide a uniform and stable bed thickness for the fluidization and combination reaction of hydrogen fluoride gas.

[0060] Furthermore, the conveying shaft 4 has a hollow structure. The bottom end of the conveying shaft 4 is provided with a feed port 22, and the top end of the conveying shaft 4 is provided with a discharge port 18 that is connected to the material laying pipe 19. A spiral auger 5 is also rotatably installed inside the conveying shaft 4. A second transmission belt 7 is provided between the motor 8 and the spiral auger 5 (both the second transmission belt 7 and the first transmission belt 6 are set as differential transmission belts so that the rotational drive acting on the spiral auger 5 is much greater than the rotational drive of the conveying shaft 4). When the motor 8 is running, it drives the spiral auger 5 to rotate rapidly relative to the conveying shaft 4 through the second transmission belt 7, which spirally conveys the aluminum hydroxide fed from the feed port 22 and returns it to the material laying pipe 19 through the discharge port 18 for re-laying.

[0061] It should be noted that, since the second turntable 13 is flat above the fluidization chamber, it not only serves to rotate and lay the aluminum hydroxide bed in the material laying pipe 19, but also serves to limit the re-laying of the aluminum hydroxide bed in the fluidization chamber. This ensures that the aluminum hydroxide bed remains uniform and full when it is re-laid inside the fluidization chamber, and does not become over-excessive, thus preparing for the subsequent uniform fluidization reaction.

[0062] like Figure 4 , Figures 15-20 As shown, to achieve uniform dispersion during the re-laying of the aluminum hydroxide bed, a pushing and crushing structure is provided inside the laying pipe 19. This structure responds to the rotational drive of the rotating component and is used for the crushing and laying of aluminum hydroxide particles back into the laying pipe 19. Specifically:

[0063] like Figures 16-18As shown, the feeding and crushing structure includes a conveyor belt 36 arranged inside the feeding pipe 19. A circulation chamber is formed between the conveyor belt 36 and the feeding pipe 19. A sieve plate 39 is provided at the bottom of the circulation chamber for screening aluminum hydroxide particles during feeding and crushing. Furthermore, blades 38 are symmetrically arranged in pairs within the circulation chamber. The blades 38 are rotatably mounted on the conveyor belt 36. As the feeding pipe 19 rotates around the fluidizing chamber, its rotational driving force acts synchronously on the conveyor belt 36, driving the conveyor belt 36 to operate in a closed loop. Subsequently, during the operation of the conveyor belt 36, the blades 38 move synchronously around the circulation chamber. Simultaneously, they flip over to circulate between the pusher plate and the paddle plate. When they approach the pusher plate structure, they are used to push the aluminum hydroxide particles into the circulation chamber for unloading, so that the aluminum hydroxide particles are dispersed to various parts of the spreading pipe 19 and screened by the screen plate 39. When they approach the paddle plate structure, they are used for the stirring and crushing process of the aluminum hydroxide particles in the circulation chamber, so that the aluminum hydroxide particles that have agglomerated due to accumulation and other reasons are dispersed, providing uniformity of dispersion when the aluminum hydroxide particles are redistributed. The uniformly dispersed aluminum hydroxide particles are discharged through the spreading cone 33 and redistributed in the fluidization chamber to form a new aluminum hydroxide bed.

[0064] As a further solution to this embodiment, such as Figure 4 , Figures 15-16 As shown, a gear ring 21 is arranged on the rotation path of the laying pipe 19, and a drive shaft 34 is provided at both ends of the conveyor belt 36. One end of the drive shaft 34 is provided with a gear pair 20 that meshes with the gear ring 21 (the gear pair 20 is a differential gear pair structure, so that when the laying pipe 19 rotates, the gear pair 20 drives the drive shaft 34 to rotate faster, thereby driving the conveyor belt 36 and the blade 38 to rotate rapidly). The drive shaft 34 is provided with a drive pulley 35 in the axial direction, which meshes with the toothed belt 37 located on the inner ring of the conveyor belt 36. By using the meshing transmission of the gear pair 20 and the gear ring 21, the drive shaft 34 is driven to rotate rapidly. Then, under the cooperation of the drive pulley 35 and the toothed belt 37, a driving force is generated on the conveyor belt 36, so that the conveyor belt 36 pushes the blade 38 to rotate around the circulation cavity, so that the aluminum hydroxide particles are evenly distributed in various parts of the laying pipe 19.

[0065] Furthermore, such as Figures 19-20As shown, a second sector gear 43 is provided at one end of the blade 38, and two sets of sector toothed belts 42 are arranged inside the rotation trajectory of the conveyor belt 36, respectively meshing with the second sector gear 43. While the conveyor belt 36 pushes the blade 38 to rotate around the circulation cavity, it drives the second sector gear 43 to move synchronously along the sector toothed belts 42, converting the linear meshing force into rotational force, pushing the blade 38 to rotate, so that the blade 38 dynamically transforms from a pusher plate to a paddle plate. By utilizing the rapid flipping of the two adjacent sets of blades 38, the synchronous crushing and dispersion of aluminum hydroxide particles in the circulation cavity during the pushing and spreading process is realized.

[0066] It should be noted that, as Figures 18-19 As shown, the upper and lower ends of the conveyor belt 36 are provided with track grooves 44, and the upper and lower ends of the material laying pipe 19 chamber are provided with first limiting guide rails 40. The first limiting guide rails 40 are slidably connected to the track grooves 44 to form a primary limiting support acting on the conveyor belt 36. Furthermore, a second limiting guide rail 41 is provided inside the conveyor belt 36. By fixing the second limiting guide rail 41 to the material laying pipe 19, a secondary limiting support acting on the conveyor belt 36 is formed. The second limiting guide rail 41 is also fixedly connected to the fan-shaped toothed belt 42 to support the meshing drive of the fan-shaped toothed belt 42 and the second fan-shaped gear 43.

[0067] like Figures 4-5 As shown, in order to achieve the consistency of internal and external temperatures during the fluidized bed reaction of aluminum hydroxide, the first turntable 11 is provided with a first heating coil 27, and the second turntable 13 is provided with a second heating coil 28. By utilizing the heating of the two sets of heating coils, the heating of the aluminum hydroxide bed after it has been re-laid in the fluidization chamber can be achieved, thus ensuring the consistency of the reaction temperature inside and outside the aluminum hydroxide bed.

[0068] In addition to the above, a discharge port 10 is provided at the bottom of the fluidized bed 1, and a feed port 9 is provided on the body of the fluidized bed 1 for feeding aluminum hydroxide before the reaction and discharging it after the reaction. When producing aluminum fluoride, aluminum hydroxide particles are fed into the bottom of the fluidized bed 1 through the feed port 9 in advance. At this time, the aluminum hydroxide particles are spirally conveyed by the combination of the conveying shaft 4 and the screw conveyor 5, and sequentially laid in the fluidized chamber through the laying pipe 19 to form an aluminum hydroxide bed. After the aluminum hydroxide bed fluidizes and reacts to produce aluminum fluoride products, the discharge port 10 is opened so that the aluminum fluoride products in the fluidized chamber are directly discharged through the discharge port 10 during the unloading process.

[0069] During use (operation), the rotation drive of the conveying shaft 4 by the motor 8, under the synchronous rotation of the fixed sleeve 17, generates a driving force to drive the first turntable 11 and the second turntable 13 to rotate synchronously. While the second turntable 13 rotates, it drives the air intake channel 24 to rotate around the aluminum hydroxide bed. At this time, hydrogen fluoride gas is transported to the first rotating channel 14 through the air intake port 2. Utilizing the rotational characteristics of the first rotating channel 14, the hydrogen fluoride gas is always guided and transported to the rotating air intake channel 24, and a fluidized tumbling reaction is carried out around the aluminum hydroxide bed in a circumferential rotational form. This ensures that the fluidized reaction of hydrogen fluoride gas and aluminum hydroxide bed is always in a suitable fluidized tumbling state. Simultaneously, while the first turntable 11 rotates, it drives the exhaust channel 16 to rotate synchronously, which acts on the timely guidance and transportation of hydrogen fluoride gas after the fluidized reaction, and the hydrogen fluoride waste gas is timely guided and transported out through the second rotating channel 15.

[0070] Furthermore, as the second turntable 13 rotates, it drives the unloading channel 23 to rotate synchronously around the fluidization chamber. At this time, the rotation of the fixed sleeve 17 drives the combination of the first sector rack 31 and the second sector rack 32 in the transmission track 26 to rotate synchronously, and they mesh with the first sector gear 30 on the opening and closing flap 25 in sequence, controlling the opening and closing flap 25 in the fluidization chamber to rotate and open and close in sequence, so that the aluminum hydroxide bed in the corresponding fluidization chamber is unloaded through the unloading channel 23 in sequence. The unloaded aluminum hydroxide particles gather at the bottom of the fluidization bed 1. At this time, the motor 8 drives the spiral auger 5 to rotate rapidly relative to the conveying shaft 4, and the aluminum hydroxide particles are conveyed to the spreading pipe 19. Since the spreading pipe 19 rotates synchronously with the first turntable 11, the aluminum hydroxide particles that return to the spreading pipe 19 are crushed and screened by the internal pushing and crushing structure, and are uniformly dispersed and then re-spread in the fluidization chamber in sequence to form an aluminum hydroxide bed, which prepares for the subsequent continuous and uniform fluidization reaction.

[0071] It should be noted that in the dry process of this design, powdered aluminum hydroxide and hydrogen fluoride gas are subjected to a full fluidization reaction at a temperature of 500-600°C. Because aluminum hydroxide dehydrates upon heating to form aluminum oxide, which then reacts with hydrogen fluoride to produce aluminum fluoride (reaction formula: 2Al(OH)3 + 6HF → 2AlF3+),... In the fluidized bed of aluminum hydroxide (6H2O), aluminum fluoride is dynamically distributed and discharged from the discharge port 10 along with the aluminum hydroxide bed for screening and other collection processes. The water vapor from the fluidization reaction and the unreacted hydrogen fluoride gas are discharged through the exhaust channel 16 and enter the tail gas treatment system. In this process, aluminum hydroxide is usually added to the reactor once and does not need to be replaced until the reaction is completed and aluminum fluoride is produced. Therefore, when hydrogen fluoride gas reacts with the aluminum hydroxide bed, the air force acts on the "fluidization tumbling" of the aluminum hydroxide bed, resulting in uneven bed height after the fluidization reaction (the bed is too high, resulting in insufficient subsequent fluidization reaction; the bed is too low, resulting in shortened gas-solid contact time and affecting reaction efficiency). Therefore, during the fluidization reaction, by re-laying the aluminum hydroxide bed after the fluidization reaction in the fluidization chamber, the uniform spreading characteristics of the aluminum hydroxide bed in the subsequent fluidization reaction can be maintained, so that the fluidization reaction of hydrogen fluoride is always maintained in a stable and efficient state.

Claims

1. A method for producing aluminum fluoride from fluorite tailings waste, characterized in that, Includes the following steps: Step 1: Mix the purified fluorite tailings with concentrated sulfuric acid in a certain proportion, and heat the mixture in a rotary kiln to generate hydrogen fluoride gas. Step 2: Hydrogen fluoride gas is introduced into the fluidized bed (1). The hydrogen fluoride gas in the fluidized bed (1) undergoes a fluidization reaction in a rotating manner around the aluminum hydroxide bed, and the aluminum hydroxide bed is driven to tumble under the flow of hydrogen fluoride gas. Step 3: The hydrogen fluoride gas after the fluidization reaction is discharged from the fluidized bed (1), and the aluminum hydroxide bed after fluidization and tumbling is re-laid to form a uniformly spread aluminum hydroxide bed again, so as to continue the fluidization reaction in a uniform manner and finally generate aluminum fluoride. The fluidized bed (1) is equipped with a rotating assembly, wherein; The rotating component includes: The material distribution plate (12) is located inside the fluidized bed (1). The material distribution plate (12) forms a split-type fluidized cavity inside, which is used for laying the aluminum hydroxide bed. The second turntable (13) is located below the fluidization chamber and has an air intake channel (24) on its surface. The first turntable (11) is located above the fluidization chamber and has an exhaust channel (16) on its surface. The intake channel (24) and the exhaust channel (16) form a hydrogen fluoride gas delivery channel, so that the hydrogen fluoride gas rotates and fluidizes around the aluminum hydroxide bed.

2. The method for producing aluminum fluoride from fluorite tailings waste according to claim 1, characterized in that, The rotating assembly also includes: The opening and closing flaps (25) are installed separately and rotatably at the bottom of each fluidization chamber; A fixed sleeve (17) is rotatably installed in the middle of the material distribution plate (12). A transmission track (26) is formed in the middle of the fixed sleeve (17). A first sector rack (31) is provided on one side of the transmission track (26), and a second sector rack (32) is provided on the other side of the transmission track (26). The fluidization chamber is provided with a rotating shaft (29) for the opening and closing flap (25) to swing and rotate. A first sector gear (30) is provided at one end of the rotating shaft (29). When the first sector rack (31) and the second sector rack (32) pass through the first sector gear (30), they are used to open and close the flap (25) to swing and rotate, and to unload the aluminum hydroxide bed after fluidization reaction in the fluidization chamber.

3. The method for producing aluminum fluoride from fluorite tailings waste according to claim 2, characterized in that, The rotating assembly also includes: The unloading channel (23) is located below the swing path of the opening and closing flap (25); The material laying pipe (19) is located on one side above the swing path of the opening and closing flap (25) and is offset from the unloading channel (23); The unloading channel (23) and the laying pipe (19) form an aluminum hydroxide bed conveying channel, so that the fluidized aluminum hydroxide bed is unloaded and re-laid in the fluidization chamber.

4. The method for producing aluminum fluoride from fluorite tailings waste according to claim 3, characterized in that, The fluidized bed (1) is provided with a conveying shaft (4) in the middle of its inner side. The conveying shaft (4) is fixedly connected to the fixed sleeve (17) for the circumferential rotation reaction of hydrogen fluoride gas around the aluminum hydroxide bed and the unloading of the aluminum hydroxide bed after fluidization and tumbling. The conveying shaft (4) is equipped with a spiral auger (5) for the return laying of the aluminum hydroxide bed after unloading.

5. The method for producing aluminum fluoride from fluorite tailings waste according to claim 4, characterized in that, The material spreading pipe (19) is equipped with a material pushing and crushing structure. The material pushing and crushing structure responds to the rotation drive of the rotating component and is used for the crushing and spreading of aluminum hydroxide particles back into the material spreading pipe (19). The material pushing and crushing structure includes: The conveyor belt (36) is installed inside the material laying pipe (19) and forms a circulation chamber with the material laying pipe (19) at intervals. The bottom of the circulation chamber is provided with a screen plate (39). Blades (38) are arranged in pairs symmetrically in the circulation chamber, and at least one set is provided. The blades (38) are rotatably mounted on the conveyor belt (36), and a second sector gear (43) is provided at one end of the blades (38). The fan-shaped toothed belt (42) is arranged inside the rotation track of the transmission belt (36) and meshes with the second fan-shaped gear (43), so that when the transmission belt (36) pushes the blade (38) to be conveyed along the circulation cavity, the blade (38) is dynamically transformed from a pusher plate to a paddle plate.

6. The method for producing aluminum fluoride from fluorite tailings waste according to claim 5, characterized in that, The feeding and crushing structure also includes: The toothed ring (21) is arranged on the rotation path of the material laying pipe (19); Toothed belt (37) is provided on the inner ring of the transmission belt (36), and at least one set is provided; The drive shaft (34) is provided in two sets, which are respectively arranged at both ends of the transmission belt (36). The drive shaft (34) is provided with a drive pulley (35) that meshes with the toothed belt (37) in the axial direction. One end of one set of drive shaft (34) is provided with a gear pair (20) that meshes with the toothed ring (21) to generate driving force for the transmission belt (36).

7. The method for producing aluminum fluoride from fluorite tailings waste according to claim 6, characterized in that, The opening and closing flap (25) is a fan-shaped mesh structure, and the unloading channel (23) is a fan-shaped frame structure. The unloading channel (23) and the opening and closing flap (25) are coaxial, and the unloading opening of the unloading channel (23) is larger than the plate surface of the opening and closing flap (25).

8. The method for producing aluminum fluoride from fluorite tailings waste according to claim 6, characterized in that, The first turntable (11) has a first heating coil (27) on its surface, and the second turntable (13) has a second heating coil (28) on its surface.

9. A method for producing aluminum fluoride from fluorite tailings waste according to claim 6, characterized in that, The intake channel (24) has a first rotating channel (14) on one side of its rotation path, wherein the first rotating channel (14) is connected to the intake channel (24). A second rotating channel (15) is provided on one side of the rotation path of the exhaust channel (16), wherein the second rotating channel (15) is connected to the exhaust channel (16).

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