Method for producing aluminum fluoride from fluorite tailing waste residues

Abstract

The invention discloses a method for producing aluminum fluoride from fluorite tailing waste residues, and relates to the technical field of aluminum fluoride production processes. The method for producing the aluminum fluoride from the fluorite tailing waste residues comprises the following steps that firstly, purified fluorite tailings and concentrated sulfuric acid are mixed in proportion and heated in a rotary kiln for a reaction, and hydrogen fluoride gas is generated; 2, hydrogen fluoride gas is introduced into the fluidized bed, the hydrogen fluoride gas in the fluidized bed is subjected to a fluidization reaction in the posture of rotating around the aluminum hydroxide bed layer, and the aluminum hydroxide bed layer is driven to roll under flowing of the hydrogen fluoride gas. Under the driving of the rotating assembly in the fluidized bed, the hydrogen fluoride gas is pushed to rotate around the aluminum hydroxide bed layer to carry out fluidization combination reaction, so that the hydrogen fluoride gas always passes through the aluminum hydroxide bed with uniform thickness to act on the uniform rolling fluidization reaction of the aluminum hydroxide bed layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluorided aluminum production process, in particular to a method for producing fluorided aluminum from fluorite tailings. BACKGROUND

[0002] The technical process for producing fluorided aluminum from fluorite tailings is an important direction for realizing tailings resource utilization and reducing solid waste pollution. The mainstream process for industrial production of fluorided aluminum is currently "wet process" and "dry process". In the dry process, powdered aluminum hydroxide is mixed with hydrogen fluoride gas at a temperature of 500-600°C to react. The aluminum hydroxide is dehydrated into aluminum oxide by heating, and then reacts with hydrogen fluoride.

[0003] In a Chinese patent with publication number CN120157163A, a process and system for producing fluorided aluminum from low-grade fluorite by dry method are disclosed. In this process, purified hydrogen fluoride gas and dried aluminum hydroxide are added to the fluidized bed reactor. At this time, the aluminum hydroxide is transported from the aluminum hydroxide bin to the top bed and reacts with the hydrogen fluoride gas. The aluminum hydroxide in the top bed enters the bottom bed through the overflow pipe and continues to react with the hydrogen fluoride gas, allowing the hydrogen fluoride gas to flow through the dynamic double-layer fluidized bed for fluidized reaction.

[0004] In the fluidized bed reactor, when the hydrogen fluoride gas flows upward from the bottom of the reactor, the gas only passes through the gap between the particles when the flow rate is low, and the particles are stationary (fixed bed state). As the flow rate increases, the upward drag force and buoyancy of the gas on the particles increase. When the flow rate reaches the critical fluidization velocity, the drag force + buoyancy is equal to the weight of the particles, and the particles begin to detach from the fixed state and exhibit a rolling fluidized state. If the flow rate continues to rise to the entrainment velocity, the particles will be carried out of the reactor by the gas. Therefore, the flow rate of hydrogen fluoride gas and the fluidized state of aluminum hydroxide determine the fluidized reaction performance. However, in the existing form of fluidized reaction, due to the dynamic flow characteristics of aluminum hydroxide, the bed thickness often cannot be maintained uniformly. When the aluminum hydroxide bed is thick, the hydrogen fluoride gas has a low passing rate. When the aluminum hydroxide bed is thin, the aluminum hydroxide particles are easily carried away by the hydrogen fluoride gas, causing the bed to be "permeable" and the fluidized reaction to be incomplete, resulting in low reaction efficiency of hydrogen fluoride gas during the fluidized reaction. SUMMARY

[0005] To overcome the shortcomings of the prior art, the present application provides a method for producing fluorided aluminum from fluorite tailings.

[0006] To achieve the above purpose, the present application is implemented by the following technical scheme: a method for producing fluorided aluminum from fluorite tailings, comprising the following steps: Step one, the purified fluorite tailings and concentrated sulfuric acid are mixed in proportion, heated in a rotary kiln to react, generate hydrogen fluoride gas; Step two, the hydrogen fluoride gas is introduced into the fluidized bed, the hydrogen fluoride gas in the fluidized bed is in a posture of rotating around the aluminum hydroxide bed layer for fluidized reaction, and the hydrogen fluoride gas drives the aluminum hydroxide bed layer to tumble under the flow of the hydrogen fluoride gas; Step three, the hydrogen fluoride gas after fluidized reaction is discharged from the fluidized bed, and the aluminum hydroxide bed layer after fluidized tumbling is re-laid to form a uniform aluminum hydroxide bed layer again to continuously and uniformly carry out fluidized reaction, and finally generate aluminum fluoride.

[0007] Further, the fluidized bed is provided with a rotating assembly, wherein; the rotating assembly comprises: a distributing disc located in the fluidized bed, the inside of the distributing disc forms a split arrangement of fluidized cavities, and the fluidized cavities are used for laying the aluminum hydroxide bed layer; a second rotating disc is arranged below the fluidized cavities and provided with an air inlet channel on the disc surface; a first rotating disc is arranged above the fluidized cavities and provided with an air outlet channel on the disc surface; the air inlet channel and the air outlet channel form a hydrogen fluoride gas conveying channel to make the hydrogen fluoride gas rotate and fluidize around the aluminum hydroxide bed layer.

[0008] Further, the rotating assembly further comprises: an opening and closing flap which is split and rotatably installed at the bottom of each fluidized cavity; a fixed sleeve is rotatably installed in the middle of the distributing disc, wherein the middle of the fixed sleeve forms a transmission track, one side of the transmission track is provided with a first sector gear rack, and the other side of the transmission track is provided with a second sector gear rack; the fluidized cavity is provided with a rotating shaft for providing the opening and closing flap with a deflection rotation, and the rotating shaft is provided with a first sector gear at one end, so that when the first sector gear rack and the second sector gear rack pass through the first sector gear respectively, the deflection rotation of the opening and closing flap is used to unload the aluminum hydroxide bed layer after fluidized reaction in the fluidized cavity.

[0009] Further, the rotating assembly further comprises: an unloading channel arranged below the deflection path of the opening and closing flap; a laying pipeline arranged on one side above the deflection path of the opening and closing flap and staggered with the unloading channel; the unloading channel and the laying pipeline form an aluminum hydroxide bed layer conveying channel to unload the aluminum hydroxide bed layer after fluidized tumbling and re-lay it in the fluidized cavity.

[0010] Further, the inside middle part of the fluidized bed is provided with a conveying shaft, wherein the conveying shaft is fixedly connected with the fixed sleeve, and is used for circumferential rotation reaction of the hydrogen fluoride gas around the aluminum hydroxide bed layer and unloading of the aluminum hydroxide bed layer after fluidized tumbling; a spiral auger is rotatably installed in the inside of the conveying shaft, and is used for re-laying the aluminum hydroxide bed layer after unloading.

[0011] Further, the paving pipeline is internally provided with a pushing and crushing structure, which is driven to rotate by the rotating assembly and used for pushing and crushing the aluminum hydroxide particles in the paving pipeline, wherein the pushing and crushing structure comprises: a conveying belt arranged in the paving pipeline and spaced from the paving pipeline to form a circulating cavity, wherein the bottom of the circulating cavity is provided with a sieve plate used for screening the aluminum hydroxide particles during pushing and crushing; a leaf plate arranged in the circulating cavity in a two-by-two symmetrical form and provided with at least one group, wherein the leaf plate is rotatably installed on the conveying belt and provided with a second sector gear at one end of the leaf plate; and a sector gear belt arranged inside the rotating track of the conveying belt and meshed with the second sector gear, so that when the conveying belt drives the leaf plate to move along the circulating cavity, the leaf plate is dynamically converted from a pushing plate to a paddle plate, and used for pushing and crushing the aluminum hydroxide bed in the circulating cavity.

[0012] Further, the pushing and crushing structure further comprises: a gear ring arranged on the rotating path of the paving pipeline; a gear belt arranged on the inner ring of the conveying belt and provided with at least one group; and a transmission shaft provided with two groups and arranged at two ends of the conveying belt, wherein the transmission shaft is provided with a transmission pulley meshed with the gear belt in the axial direction, and one end of one group of the transmission shaft is provided with a gear pair meshed with the gear ring, so as to generate a driving force for the conveying belt.

[0013] Further, the opening and closing flap is a sector-shaped mesh plate structure, and the discharge channel is a sector-shaped frame structure, the discharge channel and the opening and closing flap are coaxial, and the discharge opening of the discharge channel is larger than the plate surface of the opening and closing flap.

[0014] Further, the plate surface of the first rotating disc is provided with a first heating coil, and the plate surface of the second rotating disc is provided with a second heating coil.

[0015] Further, one side of the rotating path of the gas inlet channel is provided with a first rotating channel, wherein the first rotating channel is connected with the gas inlet channel in a conductive manner; and one side of the rotating path of the gas outlet channel is provided with a second rotating channel, wherein the second rotating channel is connected with the gas outlet channel in a conductive manner.

[0016] The present application has the following beneficial effects: (1) The method for producing aluminum fluoride from the fluorite tailings waste residue, when the hydrogen fluoride gas is introduced into the fluidized bed, the hydrogen fluoride gas is driven to rotate around the aluminum hydroxide bed by the driving of the rotating assembly in the fluidized bed, so that the hydrogen fluoride gas always passes through the aluminum hydroxide bed with uniform thickness and is subjected to the uniform tumbling fluidization combination reaction of the aluminum hydroxide bed, thereby improving the stability and comprehensiveness of the combination reaction of the hydrogen fluoride gas and the aluminum hydroxide bed.

[0017] (2), the method for producing aluminum fluoride from the fluorite tailings waste, through the setting of the rotating assembly, it can re-lay the hydrogen oxide aluminum bed layer while pushing the hydrogen fluoride gas to rotate around the hydrogen oxide aluminum bed layer, and form the hydrogen oxide aluminum bed layer again in the uniform paving state, prepare for the continuous circumferential rotation reaction of hydrogen fluoride, so that the combination reaction of hydrogen fluoride gas and hydrogen oxide aluminum bed layer is always in uniform dynamic combination.

[0018] (3), the method for producing aluminum fluoride from the fluorite tailings waste, when the rotating assembly acts on the circulating laying of the hydrogen oxide aluminum bed layer, through the setting of the pushing and crushing structure, it can not only play the role of uniform unloading when the hydrogen oxide aluminum bed layer is re-laid, but also can play the role of pre-crushing of hydrogen oxide aluminum particles, reduce the "agglomeration" phenomenon of hydrogen oxide aluminum bed layer in the stacking process, and improve the combination reaction of hydrogen fluoride gas and hydrogen oxide aluminum bed layer.

[0019] (4), the method for producing aluminum fluoride from the fluorite tailings waste, when the rotating assembly re-lays the hydrogen oxide aluminum bed layer, it can make the internal particles of the hydrogen oxide aluminum bed layer recombine and arrange, at this time, through the heating coil arranged above and below the hydrogen oxide aluminum bed layer, it can act on the real-time heating of the hydrogen oxide aluminum bed layer, ensure the consistency of the reaction temperature inside and outside the hydrogen oxide aluminum bed layer, avoid the uneven temperature, and lead to the insufficient reaction conversion rate and the sharp increase of energy consumption.

[0020] Of course, implementing any product of the present application does not necessarily need to achieve all the advantages described above at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The process flow chart of the present application; Figure 2 The first structure diagram of the fluidized bed in the present application; Figure 3 The second structure diagram of the fluidized bed in the present application; Figure 4 The first assembly diagram of the rotating assembly in the present application; Figure 5 The second assembly diagram of the rotating assembly in the present application; Figure 6 The partial sectional view of the rotating assembly in the present application; Figure 7 The driving diagram of the rotating assembly in the present application; Figure 8 The first flow diagram of hydrogen fluoride gas in the present application; Figure 9 The second flow diagram of hydrogen fluoride gas in the present application; Figure 10Schematic diagram of arrangement of opening and closing flaps in the application; Figure 11 Schematic diagram of opening and closing of opening and closing flaps in the application; Figure 12 Schematic diagram of driving of opening and closing flaps in the application; Figure 13 First unloading schematic diagram of aluminum hydroxide bed layer in the application; Figure 14 Second unloading schematic diagram of aluminum hydroxide bed layer in the application; Figure 15 First assembly schematic diagram of pushing and crushing structure in the application; Figure 16 Second assembly schematic diagram of pushing and crushing structure in the application; Figure 17 Third assembly schematic diagram of pushing and crushing structure in the application; Figure 18 Structural schematic diagram of material laying pipeline in the application; Figure 19 First driving schematic diagram of pushing and crushing structure in the application; Figure 20 Second driving schematic diagram of pushing and crushing structure in the application.

[0022] In the figure, 1, fluidized bed; 2, air inlet; 3, air outlet; 4, conveying shaft; 5, spiral auger; 6, first transmission belt; 7, second transmission belt; 8, motor; 9, feeding port; 10, unloading port; 11, first rotary disc; 12, distribution disc; 13, second rotary disc; 14, first rotary channel; 15, second rotary channel; 16, exhaust channel; 17, fixed sleeve; 18, unloading pipe; 19, material laying pipeline; 20, gear pair; 21, gear ring; 22, feeding pipe; 23, unloading channel; 24, air inlet channel; 25, opening and closing flap; 26, transmission track; 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 laying cone hopper; 34, transmission shaft; 35, transmission pulley; 36, transmission belt; 37, toothed belt; 38, leaf plate; 39, sieve plate; 40, first limiting guide rail; 41, second limiting guide rail; 42, sector toothed belt; 43, second sector gear; 44, track sliding groove. DETAILED DESCRIPTION

[0023] With reference to the accompanying drawings: the technical solutions in the embodiments of the present application will be apparently and completely described, obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0024] In the description of the present application, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "periphery" and the like indicate the orientation or positional relationship, only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the components or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation of the present application.

[0025] According to the following Figures 1-20 A method for producing aluminum fluoride from fluorite tailings waste is described.

[0026] As Figure 1 shown, a method for producing aluminum fluoride from fluorite tailings waste includes the following steps: Step one, mix the purified fluorite tailings with concentrated sulfuric acid in proportion, heat and react in a rotary kiln to generate hydrogen fluoride gas; Step two, pass the hydrogen fluoride gas into the fluidized bed 1, the hydrogen fluoride gas in the fluidized bed 1 flows around the aluminum hydroxide bed layer in a rotating posture for fluidized reaction, and drives the aluminum hydroxide bed layer to tumble under the flow of hydrogen fluoride gas; Step three, the hydrogen fluoride gas after fluidized reaction is discharged from the fluidized bed 1, the fluidized and tumbled aluminum hydroxide bed layer is re-laid, and a uniform and flat aluminum hydroxide bed layer is formed again to prepare for the next fluidization.

[0027] As Figures 2-9As shown, in order to realize the hydrogen fluoride gas rotating around the aluminum hydroxide bed layer, the fluidized combination reaction is carried out, the rotating assembly is arranged in the fluidized bed 1, wherein the rotating assembly comprises a distributing disc 12 fixed in the fluidized bed 1, the distributing disc 12 is internally formed with a split type arranged fluidized cavity, the fluidized cavity is used for laying the aluminum hydroxide bed layer (the fluidized cavity is arranged in a split type of fan shape, so as to separate the aluminum hydroxide bed layer into independent and uniformly laid bed layer structure), a second rotating disc 13 is arranged below the fluidized cavity, and an air inlet channel 24 is arranged on the disc surface of the second rotating disc 13, a first rotating disc 11 is arranged above the fluidized cavity, and an air outlet channel 16 is arranged on the disc surface of the first rotating disc 11, the air inlet channel 24 and the air outlet channel 16 form a hydrogen fluoride gas conveying channel (the air inlet channel 24 and the air outlet channel 16 are arranged in alignment with each other, and the air inlets thereof are respectively opposite to the bottom and the top of the fluidized cavity), so that the hydrogen fluoride gas rotates around the aluminum hydroxide bed layer for the fluidized reaction, the first rotating disc 11 and the second rotating disc 13 are driven to rotate, the air inlet channel 24 and the air outlet channel 16 are driven to rotate around the fluidized cavity, so that the hydrogen fluoride gas input through the air inlet channel 24 is conveyed out through the air outlet channel 16 for the first time after passing through the aluminum hydroxide bed layer in the fluidized cavity, and under the rotation driving, the hydrogen fluoride gas is sequentially fluidized and combined with the aluminum hydroxide bed layer in the next group of fluidized cavities, since the aluminum hydroxide bed layer is uniformly laid in the fluidized cavity, the rotation conveying of the hydrogen fluoride gas can always be fluidized and combined with the uniformly laid aluminum hydroxide bed layer, so as to ensure the sufficiency of the fluidized combination reaction, and avoid the thickness change of the aluminum hydroxide bed layer being too large, which causes the instability of the hydrogen fluoride gas fluidized combination reaction.

[0028] As a further scheme of the embodiment, as shown in Figures 3-4 、 Figure 6 , the rotating assembly further comprises a fixed sleeve 17 rotatably installed in the middle of the distributing disc 12 (the outer circle of the distributing disc 12 is fixed on the fluidized bed 1, and the inner circle is rotatably installed on the fixed sleeve 17 to support the center part), the fixed sleeve 17 is fixed with the first rotating disc 11 and the second rotating disc 13, and the fixed sleeve 17 is internally and fixedly connected with a conveying shaft 4, the conveying shaft 4 is rotatably installed in the middle of the inner side of the fluidized bed 1, wherein a motor 8 is arranged on the fluidized bed 1, a first transmission belt 6 is arranged between the motor 8 and the conveying shaft 4, the motor 8 is used as a driving source, the first transmission belt 6 is used for transmission, the conveying shaft 4 is driven to rotate, the fixed sleeve 17 generates the rotating driving force acting on the first rotating disc 11 and the second rotating disc 13, so that the air inlet channel 24 and the air outlet channel 16 rotate around the aluminum hydroxide bed layer, and the dynamic fluidized combination reaction of the hydrogen fluoride gas is carried out.

[0029] Further, as shown in Figures 8-9As shown, the rotating path side of the gas inlet channel 24 is provided with the first rotating channel 14, and the rotating path side of the gas outlet channel 16 is provided with the second rotating channel 15. The first rotating channel 14 and the second rotating channel 15 are respectively rotatably installed on the fluidized bed 1 and are respectively provided with the gas inlet 2 and the gas outlet 3 (as shown in Figure 4 、 Figure 5 As shown, the first rotating channel 14 and the second rotating channel 15 are both divided into inner and outer parts. The outer part is in a fixed state and is connected with the gas inlet 2 and the gas outlet 3, and the inner part is in a rotating state and is connected with the gas inlet channel 24 and the gas outlet channel 16. A sealing gasket is arranged between the inner and outer parts to realize relative sealing operation, so that the hydrogen fluoride gas before reaction flows into the rotating gas inlet channel 24, and the mixed gas after reaction is discharged from the gas outlet channel 16 to the gas outlet 3. The first rotating channel 14 is connected with the gas inlet channel 24 in a conductive manner, and the second rotating channel 15 is connected with the gas outlet channel 16 in a conductive manner. During the fluidization and combination reaction of the hydrogen fluoride gas, the hydrogen fluoride gas is transported into the first rotating channel 14 through the gas inlet 2. The rotating characteristic of the first rotating channel 14 is utilized to make the first rotating channel 14 rotate synchronously with the gas inlet channel 24 while always guiding and transporting the hydrogen fluoride gas into the gas inlet channel 24. Synchronously, the rotating characteristic of the second rotating channel 15 is utilized to make the second rotating channel 15 rotate synchronously with the gas outlet channel 16 while discharging the hydrogen fluoride exhaust gas from the gas outlet channel 16. The hydrogen fluoride exhaust gas is discharged into the subsequent cyclone dust collector device through the gas outlet 3 for dust removal, thereby providing a channel required for dynamic transportation of the hydrogen fluoride gas in the aluminum hydroxide bed layer.

[0030] It should be noted that the first rotating disc 11 and the second rotating disc 13 are respectively attached to the upper and lower sides of the distribution disc 12 to independently separate the aluminum hydroxide bed layer in the distribution disc 12 in a deep level, so that the aluminum hydroxide bed layer in each fluidized cavity of the distribution disc 12 is independently arranged. When the hydrogen fluoride gas passes through the aluminum hydroxide bed layer, it only acts on the fluidization and combination reaction of the aluminum hydroxide bed layer at that moment and does not drive the fluidization and rolling of the aluminum hydroxide bed layer in other fluidized cavities, thereby maintaining the dynamic and uniform fluidization reaction of the hydrogen fluoride gas and the aluminum hydroxide bed layer. In addition, when the hydrogen fluoride gas is input through the gas inlet channel 24, it can only pass through the corresponding aluminum hydroxide bed layer at that moment. After the fluidization and combination reaction, it is only discharged through the gas outlet channel 16. In this way, the ordered flow of the hydrogen fluoride gas is improved, and the large-scale diffusion of the hydrogen fluoride gas is avoided, thereby avoiding the large air flow fluctuation in the fluidized bed 1 and the instability of the fluidization and combination reaction.

[0031] As shown Figures 5-7 、 Figures 10-14As shown, in order to realize the re-uniform laying of the aluminum hydroxide bed after the fluidization combination reaction, the rotating assembly further comprises an opening and closing flap 25 which is split and rotatably installed at the bottom of each fluidization cavity, and a rotating shaft 29 is arranged in the fluidization cavity to provide the swing rotation of the opening and closing flap 25 (the opening and closing flap 25 has the characteristics of freely swinging downward under the rotation support of the rotating shaft 29, at this time, the opening and closing flap 25 is supported by the bottom support of the second turntable 13 acting on the fluidization cavity to maintain a horizontal state, and the bottom support of the aluminum hydroxide bed is only allowed to swing and rotate when the opening and closing flap 25 passes through the opening on the second turntable 13 to unload the aluminum hydroxide bed), and a first sector gear 30 is arranged at one end of the rotating shaft 29, wherein a transmission track 26 is formed in the middle of the fixed sleeve 17, a first sector rack 31 is arranged on one side of the transmission track 26, and a second sector rack 32 is arranged on the other side of the transmission track 26 (the combination of the first sector rack 31 and the second sector rack 32 is arranged on the front side of the rotating path of the gas inlet channel 24 and maintains a sufficient distance from the gas inlet channel 24 to provide sufficient time for the unloading and re-laying of the aluminum hydroxide bed), while the conveying shaft 4 pushes the fixed sleeve 17 to rotate, the transmission track 26 is synchronously rotated, 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 respectively, and the meshing drive of the first sector rack 31 and the second sector rack 32 acting on the first sector gear 30 respectively generates the driving force for the orderly swing rotation and resetting of the opening and closing flap 25 (as shown in Figures 10-12 During the opening and closing process of the opening and closing flap 25, the aluminum hydroxide bed in the corresponding fluidization cavity is unloaded to the bottom of the fluidized bed 1, and after the opening and closing flap 25 is closed and reset, the re-laying of the aluminum hydroxide bed is prepared, in particular: The unloading channel 23 is arranged below the swing path of the opening and closing flap 25, wherein the unloading channel 23 is arranged on the second turntable 13 and is close to the first sector rack 31 and the second sector rack 32, the opening and closing flap 25 is a sector mesh plate structure, the unloading channel 23 is a sector frame structure, the unloading channel 23 is coaxial with the opening and closing flap 25, and the unloading opening of the unloading channel 23 is larger than the plate surface of the opening and closing flap 25, while the fixed sleeve 17 drives the second turntable 13 to rotate, the unloading channel 23 synchronously passes through the opening and closing flap 25 to be opened and closed to provide the opening and closing and resetting space for the opening and closing of the opening and closing flap 25, so that the aluminum hydroxide bed in the corresponding fluidization cavity is unloaded to the bottom of the fluidized bed 1 through the unloading channel 23.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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: 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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. 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.

[0042] 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.

2. The method for producing aluminum fluoride from fluorite tailings waste according to claim 1, characterized in that, 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.

3. The method for producing aluminum fluoride from fluorite tailings waste according to claim 2, 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.

4. The method for producing aluminum fluoride from fluorite tailings waste according to claim 3, 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.

5. The method for producing aluminum fluoride from fluorite tailings waste according to claim 4, 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.

6. The method for producing aluminum fluoride from fluorite tailings waste according to claim 5, 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.

7. The method for producing aluminum fluoride from fluorite tailings waste according to claim 6, 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).

8. The method for producing aluminum fluoride from fluorite tailings waste according to claim 7, 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).

9. The method for producing aluminum fluoride from fluorite tailings waste according to claim 7, 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.

10. A method for producing aluminum fluoride from fluorite tailings waste according to claim 7, 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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