An equipment and process for recovering aluminum by co-processing aluminum electrolytic aluminum ash and waste carbon cathode

Abstract

The application provides an equipment and process for cooperatively disposing and recycling aluminum by using aluminum electrolysis aluminum ash and waste carbon cathode, relates to the technical field of aluminum electrolysis waste resource utilization, and comprises a mixing kettle, a kettle cover, a buoyancy driving mechanism, a pH adjusting mechanism, a self-adaptive adjusting mechanism and a supporting frame; the buoyancy driving mechanism comprises a mounting frame fixed to the top of the kettle cover, a rotating shaft is longitudinally rotationally connected in the mounting frame, and rotating gears are fixed to the circumferential surface of the rotating shaft. According to the scheme, after the mixed fluorine source is completely injected into the mixing kettle, the liquid level in the mixing kettle reaches a set value, at this time, the dropping hose is completely pressed to death through the rotation of the extrusion disc, the floating capsule and the floating rod stop moving upward, the dosing is automatically stopped, precise parking without overshoot is realized, the dosing speed is adaptively decreased along with the adjusting process, and the problems of overshoot, oscillation or local unevenness caused by manual or simple constant-speed dosing are fundamentally avoided, and the aluminum recovery rate and the purity of aluminum fluoride are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum electrolysis waste resource utilization, and in particular to a device and process for co-processing aluminum ash and waste carbon cathodes in aluminum electrolysis to recover aluminum. Background Technology

[0002] The aluminum electrolysis process generates large quantities of secondary aluminum ash and waste carbon cathodes. Secondary aluminum ash is a solid waste obtained after extracting metallic aluminum from aluminum slag; it contains aluminum nitride and salt refining agents, possessing both pollutant and resource-related properties. Waste carbon cathodes are solid waste generated during aluminum electrolysis due to the degradation of carbon cathodes caused by certain elements; they are rich in carbon and electrolyte components, with a fluorine content as high as 30%–50%. Currently, the primary method of disposal for these wastes is landfilling, which not only wastes resources but also pollutes soil and groundwater, releases toxic and flammable gases, and poses significant risks to humans and ecosystems.

[0003] In the fields of hydrometallurgy, chemical synthesis, and industrial solid waste resource utilization, it is often necessary to mix and react various feed solutions with different acid and alkaline properties, and precisely control the pH value of the mixed system to ensure the yield and purity of the target product. For example, in the process of recovering aluminum from aluminum electrolysis waste and preparing industrial-grade aluminum fluoride, acidic filtrate containing aluminum sulfate and alkaline filtrate containing sodium aluminate and sodium fluoride need to be mixed in a specific ratio and reacted within a narrow pH window of 5.5 to 6.5 to generate hydroxyaluminum fluoride precursor. The pH control precision during the mixing process directly affects the aluminum precipitation yield, product purity, and subsequent filtration performance.

[0004] In related technologies, the process of recovering aluminum from aluminum electrolysis waste requires mixing various filtrates with different acidity and alkalinity and adjusting the pH value. However, existing recovery equipment is not convenient for adaptively adjusting the dosing rate according to the liquid level in the vessel. If the dosing rate is too slow in the initial stage, the adjustment time is long and the efficiency is low. If the dosing rate is too fast, the pH may exceed the target value, requiring reverse dosing to correct it. This can lead to increased acid and alkali consumption or pH oscillation, and even the formation of impurities such as cryolite and aluminum hydroxide due to local over-alkalinity or over-acidity, reducing the yield and purity of the target product.

[0005] Therefore, it is necessary to provide a device for the co-processing and recycling of aluminum ash and waste carbon cathodes from aluminum electrolysis to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a device for the co-processing and recycling of aluminum ash and waste carbon cathodes from aluminum electrolysis, which solves the problem that existing recycling equipment is not convenient for adaptively adjusting the dosing speed according to the liquid level in the reactor.

[0007] To solve the above-mentioned technical problems, the equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathode provided by the present invention includes a mixing tank, a tank cover, a buoyancy drive mechanism, a pH adjustment mechanism, an adaptive adjustment mechanism, and a support frame;

[0008] The buoyancy drive mechanism includes a mounting bracket fixed to the top of the vessel lid, a rotating shaft rotatably connected to the inside of the mounting bracket, a rotating gear fixed to the circumferential side of the rotating shaft, a guide sleeve fixed to the inside of the vessel lid, a float rod slidably connected to the inside of the guide sleeve, a float bladder fixed to the bottom end of the float rod and inside the mixing vessel, and toothed grooves formed on the surface of the float rod, which meshes with the rotating gear.

[0009] The pH adjustment mechanism includes a cam with a keyway connected to the surface of a rotating shaft. A connecting bracket is fixed to the top of the mounting frame. A storage cylinder is fixed to the inner side of the connecting bracket. A piston bracket is vertically slidably connected inside the storage cylinder. A spring is sleeved on the circumferential side of the piston bracket and at the bottom of the storage cylinder. A drive wheel is rotatably connected to the inner side of the bottom of the piston bracket. The bottom of the drive wheel contacts the surface of the cam. A dripping hose is connected to the side of the storage cylinder.

[0010] The adaptive adjustment mechanism includes a half gear connected to the surface of the rotating shaft via a keyway, a rotating rod rotatably connected inside the mounting frame, an extrusion plate fixed to the circumferential side of the rotating rod, a driven gear fixed to the circumferential side of the rotating rod and in front of the extrusion plate, and a mounting seat fixed to the back of the inner wall of the mounting frame.

[0011] Preferably, the lid is disposed on the top of the mixing vessel, the mixing vessel is fixed inside the support frame, the dripping hose is disposed on the top of the mounting base, the top of the mounting base is provided with a mounting groove for use with the dripping hose, and the extrusion plate is disposed on the top of the mounting base.

[0012] Preferably, during the clockwise rotation of the half gear, it will mesh with the driven gear. After meshing, it will drive the driven gear to rotate counterclockwise. When the driven gear rotates counterclockwise, it will drive the extrusion disc to rotate through the rotating rod, so that the extrusion disc gradually extrudes the dripping tubing.

[0013] Preferably, a transmission mechanism is fixedly provided on the circumferential side of the rotating shaft and in front of the rotating gear. The transmission mechanism includes a take-up reel fixedly provided on the circumferential side of the rotating shaft and in front of the rotating gear. A rotating bracket is fixedly provided on the right side of the support frame. A roller is rotatably connected to the inner side of the rotating bracket. A transmission belt is sleeved on the circumferential side of the roller. The left side of the bottom of the transmission belt is fixedly connected to the take-up reel.

[0014] Preferably, a horizontal plate is fixedly provided on the inner side of the support frame and at the top of the mixing vessel. A liquid inlet mechanism is fixedly provided on the top of the horizontal plate. The liquid inlet mechanism includes a sliding seat fixedly provided on the top of the horizontal plate. A moving tube is slidably connected inside the sliding seat. The left side of the top of the transmission belt is fixedly connected to the right side of the moving tube. A liquid inlet pipe is connected to the bottom of the sliding seat. A through groove is opened at the bottom of the moving tube and inside the sliding seat. A connecting plate is fixedly provided on the left side of the moving tube. A sliding rod is fixedly provided on the inner side of the top of the connecting plate. The right end of the sliding rod passes through the left side of the sliding seat and extends to the inner side of the sliding seat. A return spring is sleeved on the circumferential side of the sliding rod.

[0015] Preferably, after the moving tube moves a certain distance to the right inside the sliding seat, it will be in communication with the liquid inlet tube, and sealing gaskets are provided on both sides of the sliding seat.

[0016] Preferably, a mixing mechanism is vertically rotatably connected inside the vessel lid. The mixing mechanism includes a mixing shaft vertically rotatably connected inside the vessel lid. Multiple mixing paddles are fixed on the circumferential side of the mixing shaft and inside the mixing vessel. A mixing motor for driving the mixing shaft to rotate is provided on the top of the horizontal plate.

[0017] Preferably, the top of the support frame is fixed with two sets of fixed seats, and the top of each set of fixed seats is provided with a storage tank. The bottom of the support frame is fixed with a base. The left side of the mixing vessel is connected to a liquid addition pipe, and the bottom of the mixing vessel is connected to a discharge pipe.

[0018] A process for co-processing aluminum ash from aluminum electrolysis with waste carbon cathodes to recover aluminum includes the following steps:

[0019] Step S1: Crush, grind, sieve, and dry the aluminum electrolysis ash and waste carbon cathode respectively;

[0020] Step S2: Stir the dried aluminum ash with water to remove chloride salts and hydrolyze aluminum nitride into aluminum hydroxide. Separate the solid and liquid to obtain filtrate A and filter residue A.

[0021] Step S3: Stir the filter residue A with sulfuric acid solution to react and separate the solid and liquid to obtain filtrate B rich in aluminum sulfate and filter residue B containing α-alumina and magnesium aluminum spinel;

[0022] Step S4: Stir the filter residue B with sodium hydroxide solution to further extract components such as aluminum nitride and aluminum oxide. Separate the solid and liquid to obtain filtrate C and filter residue C. Filter residue C can be used as a building material after multiple water washings.

[0023] Step S5: Mix the dried cathode carbon block with filtrate B and react them. Separate the solid and liquid components to obtain fluorine-rich filtrate D and filter residue D.

[0024] Step S6: Mix filter residue D and filtrate C and react them. Then, leach them twice and separate the solid and liquid to obtain filtrate E and filter residue E. Filter residue E is washed with water multiple times to obtain high-purity carbon blocks.

[0025] Step S7: Mix filtrate B, filtrate C, filtrate D and filtrate E at an F / Al molar ratio, adjust the pH to 5.5-6.5 and react to generate aluminum hydroxy fluoride precursor. Separate the solid and liquid to obtain filtrate F and filter residue F. Calcine the filter residue F to obtain industrial-grade aluminum fluoride.

[0026] Step S8: Mix filtrate F with filtrate A, and evaporate and concentrate to obtain sodium sulfate.

[0027] Compared with related technologies, the equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes provided by the present invention has the following beneficial effects:

[0028] In the initial stage of injecting the mixed fluorine source into the mixing vessel, the liquid level in the mixing vessel rises, which will quickly drive the float to move upward through the float bladder. The upward movement of the float will drive the rotating gear, rotating shaft and cam to rotate clockwise. The clockwise rotation of the cam will drive the piston support to move upward. At this time, the piston support moves upward at a relatively fast speed, and the pH adjustment liquid is also added at a relatively fast speed, which makes it easier to quickly pull the mixed fluorine source to the pH target value and improve the aluminum recovery efficiency.

[0029] In the later stages of injecting the mixed fluorine source into the mixing vessel, the continuous rotation of the rotating shaft will drive the extrusion plate to rotate counterclockwise through the half gear, the driven gear, and the rotating rod, thus extruding the dripping tubing. As the extrusion plate gradually flattens the dripping tubing, the speed of the pH adjustment liquid will automatically slow down to avoid overrushing. At the same time, the dripping tubing will give the half gear a reaction force. This reaction force will reduce the upward movement speed of the float and float rod as the liquid level continues to rise, thereby reducing the rotation speed of the cam and the external flow speed of the pH adjustment liquid, actively adapting to the reaction process.

[0030] After the mixed fluorine source is completely injected into the mixing vessel, the liquid level in the mixing vessel reaches the set value. At this time, the rotation of the squeezing plate will completely compress the dripping hose, and the float and float rod will stop moving upward. The dosing will stop automatically, and the precise stopping without overshoot will be achieved. The dosing speed will decrease adaptively as the adjustment process progresses, which will fundamentally avoid the problems of overshoot, oscillation or local unevenness that are common in manual or simple fixed-speed dosing. This will greatly improve the aluminum recovery rate and the purity of aluminum fluoride. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0032] Figure 1 The optimal structural schematic diagram provided for this invention;

[0033] Figure 2 This is a structural schematic diagram of the right view provided by the present invention;

[0034] Figure 3 for Figure 1 The diagram shown is a structural schematic of the mixing vessel.

[0035] Figure 4 A schematic diagram of the buoyancy drive mechanism, pH adjustment mechanism, and adaptive adjustment mechanism provided by the present invention;

[0036] Figure 5 for Figure 4 The diagram shown illustrates the structure of the pH adjustment mechanism.

[0037] Figure 6 A schematic diagram showing the state in which the float moves upward, causing the rotating gear to drive the rotating shaft and cam to rotate clockwise, as provided by the present invention.

[0038] Figure 7 for Figure 4 The diagram shows the structure of the adaptive adjustment mechanism.

[0039] Figure 8 A schematic diagram of the transmission mechanism and liquid inlet mechanism provided by the present invention;

[0040] Figure 9 for Figure 8 The schematic diagram of the planar cross-sectional view of the sliding seat and the moving tube shown;

[0041] Figure 10 A schematic diagram of the structure of the mixing mechanism provided by the present invention;

[0042] Figure 11 This is a schematic diagram of the process flow provided by the present invention.

[0043] Explanation of icon numbers:

[0044] 1. Mixing kettle; 2. Kettle cover;

[0045] 3. Buoyancy drive mechanism; 31. Mounting bracket; 32. Rotating shaft; 33. Rotating gear; 34. Guide sleeve; 35. Float; 36. Float;

[0046] 4. pH adjustment mechanism; 41. Cam; 42. Connecting bracket; 43. Storage cylinder; 44. Piston bracket; 45. Spring; 46. Drive wheel; 47. Dropping tubing;

[0047] 5. Adaptive adjustment mechanism; 51. Half gear; 52. Rotating rod; 53. Extrusion disc; 54. Driven gear; 55. Mounting base;

[0048] 6. Support frame;

[0049] 7. Transmission mechanism; 71. Winding reel; 72. Rotating bracket; 73. Roller; 74. Drive belt;

[0050] 8. Horizontal board;

[0051] 9. Liquid inlet mechanism; 91. Sliding seat; 92. Moving tube; 93. Liquid inlet tube; 94. Connecting plate; 95. Sliding rod; 96. Return spring;

[0052] 10. Hybrid mechanism; 101. Hybrid shaft; 102. Hybrid propeller; 103. Hybrid motor;

[0053] 11. Fixture; 12. Storage tank; 13. Base; 14. Liquid filling pipe. Detailed Implementation

[0054] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0055] This invention provides a device for the co-processing and recycling of aluminum from aluminum electrolysis ash and waste carbon cathodes.

[0056] First embodiment:

[0057] Please see Figures 1 to 7 A device for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathode includes a mixing tank 1, a tank cover 2, a buoyancy drive mechanism 3, a pH adjustment mechanism 4, an adaptive adjustment mechanism 5, and a support frame 6.

[0058] The buoyancy drive mechanism 3 includes a mounting bracket 31 fixed to the top of the vessel cover 2. A rotating shaft 32 is rotatably connected to the interior of the mounting bracket 31. A rotating gear 33 is fixed to the circumferential side of the rotating shaft 32. A guide sleeve 34 is fixed to the interior of the vessel cover 2. A float 35 is vertically slidably connected to the interior of the guide sleeve 34. A float bladder 36 is fixed to the bottom end of the float 35 and inside the mixing vessel 1. The surface of the float 35 is provided with toothed grooves. The float 35 meshes with the rotating gear 33.

[0059] The pH adjustment mechanism 4 includes a cam 41 with a keyway connected to the surface of the rotating shaft 32. A connecting bracket 42 is fixedly mounted on the top of the mounting bracket 31. A storage cylinder 43 is fixedly mounted on the inner side of the connecting bracket 42. A piston bracket 44 is vertically slidably connected inside the storage cylinder 43. A spring 45 is sleeved on the circumferential side of the piston bracket 44 and located at the bottom of the storage cylinder 43. A drive wheel 46 is rotatably connected to the inner side of the bottom of the piston bracket 44. The bottom of the drive wheel 46 is in contact with the surface of the cam 41. A dripping hose 47 is connected to the side of the storage cylinder 43.

[0060] The adaptive adjustment mechanism 5 includes a half gear 51 with a keyway connected to the surface of the rotating shaft 32. A rotating rod 52 is rotatably connected inside the mounting frame 31. An extrusion disc 53 is fixed on the circumferential side of the rotating rod 52. A driven gear 54 is fixed on the circumferential side of the rotating rod 52 and in front of the extrusion disc 53. A mounting seat 55 is fixed on the back of the inner wall of the mounting frame 31.

[0061] The lid 2 is disposed on the top of the mixing vessel 1, the mixing vessel 1 is fixed inside the support frame 6, the dripping hose 47 is disposed on the top of the mounting base 55, the top of the mounting base 55 is provided with a mounting groove for use with the dripping hose 47, and the extrusion plate 53 is disposed on the top of the mounting base 55.

[0062] During the clockwise rotation of the half gear 51, it will mesh with the driven gear 54. After meshing, it will drive the driven gear 54 to rotate counterclockwise. When the driven gear 54 rotates counterclockwise, it will drive the extrusion disc 53 to rotate through the rotating rod 52, so that the extrusion disc 53 gradually extrudes the dripping tubing 47.

[0063] Preferably, the float 36 is installed far away from the mixing impeller 102, and a perforated guide tube is installed around the float 36. After the flow generated by stirring enters the sleeve, it is throttled and diverted through the small holes, forming a micro-circulation zone in the tube. The liquid surface fluctuation is greatly attenuated, so that the float 36 is not disturbed by the horizontal liquid flow impact.

[0064] Preferably, the dripping hose 47 is used to drip pH adjustment solution into the mixing vessel 1. The mixing vessel 1 is equipped with a dropper that is connected to the dripping hose 47. The dripping point is set in the high turbulence zone of the mixing paddle 102. The solution is added by multiple dripping points. The top of the storage cylinder 43 is connected to an extraction pipe. Both the extraction pipe and the surface of the dripping hose 47 are equipped with one-way valves.

[0065] Please combine Figures 4 to 6The mixed fluoride source formed by mixing filtrate C, filtrate D and filtrate E is slowly injected into the mixing vessel 1 through the liquid addition pipe 14. As the mixed fluoride source is slowly added, under the buoyancy of the liquid, the float 36 will drive the float rod 35 to move upward. The upward movement of the float rod 35 will drive the rotating gear 33 and the rotating shaft 32 to rotate clockwise. The clockwise rotation of the rotating shaft 32 will drive the cam 41 to rotate clockwise. During the rotation of the cam 41, it will slowly push the piston support 44 upward through the drive wheel 46. The upward movement of the piston support 44 will then transport the pH adjustment liquid in the storage cylinder 43 to the mixing vessel 1 through the dripping hose 47. The liquid is then dripped into the mixed fluoride source using a dripper, thereby adjusting the pH value of the mixed fluoride source.

[0066] Please combine Figure 4 and Figure 7 As the mixed fluorine source is gradually injected into the mixing vessel 1, the liquid level in the mixing vessel 1 will gradually rise. The float 36 will also gradually drive the float rod 35 to move upward, causing the rotating gear 33 and the rotating shaft 32 to rotate continuously. During the rotation of the rotating shaft 32, the half gear 51 will rotate simultaneously. When the liquid level in the mixing vessel 1 rises to a certain position, the half gear 51 will mesh with the driven gear 54. Through the rotation of the half gear 51, the driven gear 54, the rotating rod 52 and the squeezing plate 53 will rotate counterclockwise. During the counterclockwise rotation of the squeezing plate 53, the dripping tubing 47 will be gradually squeezed, thereby controlling the speed at which the pH adjustment solution is dripped from the dripping tubing 47 in the later stage of pH adjustment of the mixed fluorine source.

[0067] Furthermore, when the squeezing disc 53 rotates counterclockwise and gradually squeezes the dripping tubing 47, the squeezing disc 53 will simultaneously be subjected to a reaction force from the dripping tubing 47. As the mixed fluoride source is gradually injected, the liquid level gradually rises. When the float 36 continuously drives the float rod 35 to rise, this reaction force will be transmitted to the rotating shaft 32 through the rotating rod 52, the driven gear 54, and the half gear 51, and then to the float rod 35 through the rotating gear 33, reducing the upward movement speed of the float rod 35. When the upward movement speed of the float rod 35 slows down, the rotation speed of the rotating shaft 32 and the cam 41 driven by the rotating gear 33 will also slow down, and consequently the upward movement speed of the piston support 44 will also slow down, and the outward flow speed of the pH adjustment liquid will also slow down accordingly.

[0068] Furthermore, when the mixed fluorine source is fully injected, the float 36 will drive the float 35 to rise to a certain height. At this time, the squeeze plate 53 will completely squeeze the dripping hose 47, stopping the dripping of pH adjuster into the mixed fluorine source. When the filtrate B is added, the float 36 will not drive the float 35 to move upward, and the rotating shaft 32 will not drive the cam 41 to rotate, completely stopping the dripping of pH adjuster.

[0069] In this embodiment, at the initial stage of injecting the mixed fluorine source into the mixing vessel 1, the liquid level in the mixing vessel 1 rises, which will quickly drive the float 35 to move upward through the float 36. The upward movement of the float 35 drives the rotating gear 33, the rotating shaft 32 and the cam 41 to rotate clockwise. The clockwise rotation of the cam 41 drives the piston support 44 to move upward. At this time, the piston support 44 moves upward at a relatively fast speed, and the pH adjustment liquid is also added at a relatively fast speed, which makes it easier to quickly pull the mixed fluorine source to the pH target value and improve the aluminum recovery efficiency.

[0070] In the later stage of the mixed fluorine source injection into the mixing vessel 1, the continuous rotation of the rotating shaft 32 will drive the squeezing plate 53 to rotate counterclockwise through the half gear 51, the driven gear 54 and the rotating rod 52, squeezing the dripping tube 47. As the squeezing plate 53 gradually flattens the dripping tube 47, the speed of the pH adjustment liquid will automatically slow down to avoid over-rushing. At the same time, the dripping tube 47 will give the half gear 51 a reaction force. This reaction force will reduce the upward movement speed of the float 36 and the float rod 35 when the liquid level continues to rise, thereby reducing the rotation speed of the cam 41 and the external flow speed of the pH adjustment liquid, actively adapting to the reaction process.

[0071] After the mixed fluorine source is completely injected into the mixing vessel 1, the liquid level in the mixing vessel 1 reaches the set value. At this time, the rotation of the squeezing plate 53 will completely press the dripping hose 47 shut, the float 36 and float rod 35 will stop moving upward, the dosing will stop automatically, and the precise stop without overshoot will be achieved. The dosing speed will be adaptively reduced as the adjustment process progresses, which will fundamentally avoid the problems of overshoot, oscillation or local unevenness that are common in manual or simple fixed-speed dosing, and greatly improve the aluminum recovery rate and the purity of aluminum fluoride.

[0072] Second embodiment:

[0073] Please see Figure 3 , Figure 8 and Figure 9 A transmission mechanism 7 is fixedly provided on the circumferential side of the rotating shaft 32 and in front of the rotating gear 33. The transmission mechanism 7 includes a take-up reel 71 fixedly provided on the circumferential side of the rotating shaft 32 and in front of the rotating gear 33. A rotating bracket 72 is fixedly provided on the right side of the support frame 6. A roller 73 is rotatably connected to the inner side of the rotating bracket 72. A transmission belt 74 is sleeved on the circumferential side of the roller 73. The left side of the bottom of the transmission belt 74 is fixedly connected to the take-up reel 71.

[0074] A horizontal plate 8 is fixedly installed on the inner side of the support frame 6 and on the top of the mixing vessel 1. A liquid inlet mechanism 9 is fixedly installed on the top of the horizontal plate 8. The liquid inlet mechanism 9 includes a sliding seat 91 fixedly installed on the top of the horizontal plate 8. A moving tube 92 is slidably connected inside the sliding seat 91. The left side of the top of the transmission belt 74 is fixedly connected to the right side of the moving tube 92. A liquid inlet pipe 93 is connected to the bottom of the sliding seat 91. A through groove is opened at the bottom of the moving tube 92 and inside the sliding seat 91. A connecting plate 94 is fixedly installed on the left side of the moving tube 92. A sliding rod 95 is fixedly installed on the inner side of the top of the connecting plate 94. The right end of the sliding rod 95 passes through the left side of the sliding seat 91 and extends to the inner side of the sliding seat 91. A return spring 96 is sleeved on the circumferential side of the sliding rod 95.

[0075] After the moving tube 92 moves a certain distance to the right inside the sliding seat 91, it will form a communication state with the liquid inlet tube 93. Both sides of the sliding seat 91 are provided with sealing gaskets.

[0076] Preferably, the moving pipe 92 is connected to the storage tank 12 on the right side via a hose. The storage tank 12 on the right side contains the filtrate B required for the mixing reaction process. The bottom end of the inlet pipe 93 is located inside the mixing vessel 1.

[0077] Please combine Figure 8 and Figure 9 During the rotation of the rotating shaft 32, the winding reel 71 will rotate clockwise. The clockwise rotation of the winding reel 71 will then wind up the transmission belt 74. During the winding process, the roller 73 will rotate and the transmission belt 74 will pull the moving tube 92 to the right. When the mixed fluorine source is completely injected into the mixing vessel 1, the transmission belt 74 will pull the moving tube 92 to the right a certain distance. The reset spring 96 will retract, so that the moving tube 92 and the liquid inlet pipe 93 are connected, thereby allowing the filtrate B in the right storage tank 12 to be added into the mixing vessel 1.

[0078] In this embodiment, if the mixed fluoride source is added to filtrate B too early, an acid-base neutralization reaction will occur directly, instantly generating a large amount of amorphous aluminum hydroxide colloid. Fluoride ions will have difficulty entering the interior of the particles, and the subsequent calcination product will be a mixture of alumina and aluminum fluoride with low purity. During the process of injecting the mixed fluoride source into the mixing vessel 1, the rotating shaft 32 will drive the winding reel 71 to rotate and wind up the transmission belt 74. When the mixed fluoride source is completely injected into the mixing vessel 1, the transmission belt 74 will pull the moving tube 92 to the right by a certain distance, so that the moving tube 92 and the liquid inlet tube 93 are connected. Then, a certain amount of filtrate B is added to the mixing vessel 1, so that the aluminum source is added at the optimal time, the precipitation is more complete, and the precipitation yield of aluminum and the fixation rate of fluoride are improved.

[0079] Third embodiment:

[0080] Please see Figure 1 , Figure 2 and Figure 10 The inside of the vessel lid 2 is vertically rotatably connected to a mixing mechanism 10. The mixing mechanism 10 includes a mixing shaft 101 vertically rotatably connected to the inside of the vessel lid 2. Multiple mixing paddles 102 are fixed on the circumferential side of the mixing shaft 101 and inside the mixing vessel 1. A mixing motor 103 for driving the mixing shaft 101 to rotate is provided on the top of the horizontal plate 8.

[0081] The top of the support frame 6 is fixed with two sets of fixed seats 11, and the top of each set of fixed seats 11 is provided with a storage tank 12. The bottom of the support frame 6 is fixed with a base 13. The left side of the mixing vessel 1 is connected to a liquid addition pipe 14, and the bottom of the mixing vessel 1 is connected to a discharge pipe.

[0082] Preferably, the liquid addition pipe 14 is connected to the storage tank 12 on the left side via a pipeline, and the storage tank 12 on the left side is provided with a mixed fluoride source after premixing filtrate C, filtrate D and filtrate E;

[0083] Please combine Figure 10 Start the mixing motor 103. The rotation of the mixing motor 103 drives the mixing shaft 101 to rotate, and the rotation of the mixing shaft 101 drives the mixing paddle 102 to rotate. The rotation of the mixing paddle 102 mixes the mixed fluorine source and filtrate B.

[0084] In this embodiment, the mixing motor 103 drives the mixing shaft 101 and the mixing paddle 102 to rotate. When the mixed fluorine source is injected, the pH adjustment liquid and the mixed fluorine source are mixed by the rotation of the mixing paddle 102. When the filtrate B is added, the mixed fluorine source and the filtrate B are mixed.

[0085] This invention also provides a process for the co-processing and recovery of aluminum from aluminum electrolysis ash and waste carbon cathode.

[0086] Please see Figure 11 A process for co-processing aluminum ash from aluminum electrolysis with waste carbon cathodes to recover aluminum includes the following steps:

[0087] Step S1: Crush, grind, sieve, and dry the aluminum electrolysis ash and waste carbon cathode respectively;

[0088] Step S2: Stir the dried aluminum ash with water to remove chloride salts and hydrolyze aluminum nitride into aluminum hydroxide. Separate the solid and liquid to obtain filtrate A and filter residue A.

[0089] Step S3: Stir the filter residue A with sulfuric acid solution to react and separate the solid and liquid to obtain filtrate B rich in aluminum sulfate and filter residue B containing α-alumina and magnesium aluminum spinel;

[0090] Step S4: Stir the filter residue B with sodium hydroxide solution to further extract components such as aluminum nitride and aluminum oxide. Separate the solid and liquid to obtain filtrate C and filter residue C. Filter residue C can be used as a building material after multiple water washings.

[0091] Step S5: Mix the dried cathode carbon block with filtrate B and react them. Separate the solid and liquid components to obtain fluorine-rich filtrate D and filter residue D.

[0092] Step S6: Mix filter residue D and filtrate C and react them. Then, leach them twice and separate the solid and liquid to obtain filtrate E and filter residue E. Filter residue E is washed with water multiple times to obtain high-purity carbon blocks.

[0093] Step S7: Mix filtrate B, filtrate C, filtrate D and filtrate E at an F / Al molar ratio, adjust the pH to 5.5-6.5 and react to generate aluminum hydroxy fluoride precursor. Separate the solid and liquid to obtain filtrate F and filter residue F. Calcine the filter residue F to obtain industrial-grade aluminum fluoride.

[0094] Step S8: Mix filtrate F with filtrate A, and evaporate and concentrate to obtain sodium sulfate;

[0095] Preferably, in step S1, aluminum electrolysis ash and waste carbon cathode are crushed and ground and sieved through a 200-mesh sieve, and then placed in an oven to dry at 100°C for 12 hours for later use.

[0096] Preferably, in step S2, 100g of dried aluminum ash and deionized water are weighed and mixed at a solid-liquid ratio of 1:3, and placed in a constant temperature water bath. The mixture is stirred at 300 rpm and reacted at 70°C for 2 hours to remove chloride salts and hydrolyze aluminum nitride into aluminum hydroxide. The solid and liquid are separated to obtain filtrate A and filter residue A.

[0097] Preferably, in step S3, filter residue A and 5 mol / L sulfuric acid solution are mixed in a solid-liquid ratio of 1:4 and placed in a constant temperature water bath. The mixture is stirred at 300 rpm and reacted at 70°C for 2 hours. Solid-liquid separation is performed to obtain filtrate B rich in aluminum sulfate and filter residue B containing α-alumina and magnesium aluminum spinel.

[0098] Preferably, in step S4, filter residue B and 3 mol / L sodium hydroxide solution are mixed in a solid-liquid ratio of 1:4 and placed in a constant temperature water bath. The mixture is stirred at 300 rpm and reacted at 70°C for 2 hours to further extract components such as aluminum nitride and aluminum oxide. The solid and liquid are separated to obtain filtrate C and filter residue C. Filter residue C can be used as a building material after multiple water washings.

[0099] Preferably, in step S5, the dried cathode carbon block and filtrate B are mixed in a solid-liquid ratio of 1:4 and placed in a constant temperature water bath. The mixture is stirred at 300 rpm and reacted at 70°C for 2 hours. The solid and liquid are separated to obtain fluorine-rich filtrate D and filter residue D.

[0100] Preferably, in step S6, filter residue D and filtrate C are mixed in a solid-liquid ratio of 1:4 and placed in a constant temperature water bath. The mixture is stirred at 300 rpm and reacted at 70°C for 2 hours for a second leaching. The solid and liquid are separated to obtain filtrate E and filter residue E. Filter residue E is washed with water multiple times to obtain high-purity carbon blocks.

[0101] Preferably, in step S7, filtrate B, filtrate C, filtrate D and filtrate E are sent for testing and mixed according to the composition at a molar ratio of F:1 of 6:1. At the same time, the pH is adjusted to 5.5, and the mixture is stirred at 300 rpm at 70°C for 2 hours to generate hydroxyl aluminum fluoride precursor. The solid and liquid are separated to obtain filtrate F and filter residue F. Filter residue F is calcined in a muffle furnace at 550°C for 3 hours to obtain industrial-grade aluminum fluoride.

[0102] Specifically, filtrate C, filtrate D and filtrate E are first mixed to form a mixed fluoride source. The pH of the mixed fluoride source is usually around 10. First, its pH value is pre-adjusted to 7.5-8.0, and then filtrate B is slowly added.

[0103] Specifically, before mixing, the mixing ratio of filtrate C, filtrate D and filtrate E is calculated based on the analysis data of each filtrate to ensure that the total F / Al molar ratio after mixing is slightly higher than the target value, and the amount of filtrate B required is calculated based on the analysis data.

[0104] Preferably, the mixed fluoride source is stored in the left-hand storage tank 12, and the filtrate B is stored in the right-hand storage tank 12.

[0105] In this embodiment, the complexation of aluminum and fluorine is utilized to replace traditional acid or alkali reagents with aluminum ash leachate, avoiding the energy consumption of traditional high-temperature roasting. Simultaneously, the efficient extraction of fluorides from waste carbon anodes is achieved. After two-step leaching, the waste carbon anodes can be used as recycled carbon materials. In addition, by adjusting the pH value and F / Al ratio, aluminum is extracted in the form of aluminum fluoride, realizing the recycling of aluminum resources, increasing the added value of resources, and making it suitable for large-scale application in the aluminum electrolysis industry.

[0106] Please refer to the reference again. Figures 1 to 10 The working principle of the equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathode provided by the present invention is as follows:

[0107] Step S1: The mixed fluoride source formed by mixing filtrate C, filtrate D and filtrate E is slowly injected into the mixing vessel 1 through the liquid addition pipe 14. When the mixed fluoride source is about to approach the float 36, the mixing motor 103 is started. The mixing motor 103 rotates and drives the mixing shaft 101 to rotate. The rotation of the mixing shaft 101 drives the mixing paddle 102 to rotate, so as to premix the mixed fluoride source.

[0108] In step S2, as the mixed fluorine source is slowly added, when the mixed fluorine source comes into contact with the float 36, under the buoyancy of the liquid, the float 36 will drive the float rod 35 to move upward. The upward movement of the float rod 35 will then drive the rotating gear 33 and the rotating shaft 32 to rotate clockwise. The clockwise rotation of the rotating shaft 32 will drive the cam 41 to rotate clockwise. During the rotation of the cam 41, it will slowly push the piston support 44 upward through the drive wheel 46. The upward movement of the piston support 44 will then transport the pH adjustment liquid in the storage cylinder 43 to the mixing vessel 1 through the dripping hose 47, and add it to the mixed fluorine source using the dripper to adjust the pH value of the mixed fluorine source.

[0109] In step S3, combined with step S2, the rotating shaft 32 will simultaneously drive the half gear 51 to rotate during rotation. When the liquid level in the mixing vessel 1 rises to a certain position, the half gear 51 will mesh with the driven gear 54. Through the rotation of the half gear 51, the driven gear 54, the rotating rod 52 and the extrusion plate 53 will rotate counterclockwise. During the counterclockwise rotation of the extrusion plate 53, it will gradually extrude the dripping tubing 47, thereby controlling the speed at which the pH adjustment solution is added by the dripping tubing 47 in the later stage of pH adjustment of the mixed fluoride source.

[0110] When the squeezing disc 53 rotates counterclockwise and gradually squeezes the dripping tubing 47, the squeezing disc 53 will simultaneously be subjected to a reaction force from the dripping tubing 47. This reaction force will be transmitted to the rotating shaft 32 through the rotating rod 52, the driven gear 54 and the half gear 51, and then to the float 35 through the rotating gear 33, reducing the upward movement speed of the float 35. When the upward movement speed of the float 35 slows down, the rotation speed of the rotating shaft 32 and the cam 41 driven by the rotating gear 33 will also slow down, and consequently the upward movement speed of the piston support 44 will also slow down, and the outward flow speed of the pH adjustment liquid will also slow down accordingly.

[0111] In step S4, when the mixed fluorine source is fully injected, the float 36 will drive the float 35 to rise to a certain height. At this time, the squeeze plate 53 will completely squeeze the dripping tubing 47, stopping the dripping of pH adjuster into the mixed fluorine source. When the filtrate B is added, the float 36 will not drive the float 35 to move upward, and the rotating shaft 32 will not drive the cam 41 to rotate, completely stopping the dripping of pH adjuster.

[0112] In step S5, during the rotation of the rotating shaft 32, the winding reel 71 will rotate clockwise. The clockwise rotation of the winding reel 71 will then wind up the transmission belt 74. During the winding process, the roller 73 will rotate and the transmission belt 74 will pull the moving tube 92 to the right. When the mixed fluorine source is completely injected into the mixing vessel 1, the transmission belt 74 will pull the moving tube 92 to the right a certain distance. The reset spring 96 will contract, so that the moving tube 92 and the liquid inlet pipe 93 are connected, allowing the filtrate B in the right storage tank 12 to be added into the mixing vessel 1.

[0113] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A device for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes, characterized in that, Includes a mixing vessel, vessel lid, buoyancy drive mechanism, pH adjustment mechanism, adaptive adjustment mechanism, and support frame; The buoyancy drive mechanism includes a mounting bracket fixed to the top of the vessel lid, a rotating shaft rotatably connected to the inside of the mounting bracket, a rotating gear fixed to the circumferential side of the rotating shaft, a guide sleeve fixed to the inside of the vessel lid, a float rod slidably connected to the inside of the guide sleeve, a float bladder fixed to the bottom end of the float rod and inside the mixing vessel, and toothed grooves formed on the surface of the float rod, which meshes with the rotating gear. The pH adjustment mechanism includes a cam with a keyway connected to the surface of a rotating shaft. A connecting bracket is fixed to the top of the mounting frame. A storage cylinder is fixed to the inner side of the connecting bracket. A piston bracket is vertically slidably connected inside the storage cylinder. A spring is sleeved on the circumferential side of the piston bracket and at the bottom of the storage cylinder. A drive wheel is rotatably connected to the inner side of the bottom of the piston bracket. The bottom of the drive wheel contacts the surface of the cam. A dripping hose is connected to the side of the storage cylinder. The adaptive adjustment mechanism includes a half gear connected to the surface of the rotating shaft via a keyway, a rotating rod rotatably connected inside the mounting frame, an extrusion plate fixed to the circumferential side of the rotating rod, a driven gear fixed to the circumferential side of the rotating rod and in front of the extrusion plate, and a mounting seat fixed to the back of the inner wall of the mounting frame.

2. The equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes according to claim 1, characterized in that, The lid is located on top of the mixing vessel, the mixing vessel is fixed inside the support frame, the dripping hose is located on top of the mounting base, the top of the mounting base has a mounting groove for use with the dripping hose, and the extrusion plate is located on top of the mounting base.

3. The equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes according to claim 1, characterized in that, During the clockwise rotation of the half gear, it will mesh with the driven gear. After meshing, it will drive the driven gear to rotate counterclockwise. When the driven gear rotates counterclockwise, it will drive the squeezing disc to rotate through the rotating rod, so that the squeezing disc gradually squeezes the dripping tubing.

4. The equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes according to claim 1, characterized in that, A transmission mechanism is fixedly provided on the circumferential side of the rotating shaft and in front of the rotating gear. The transmission mechanism includes a take-up reel fixedly provided on the circumferential side of the rotating shaft and in front of the rotating gear. A rotating bracket is fixedly provided on the right side of the support frame. A roller is rotatably connected to the inner side of the rotating bracket. A transmission belt is sleeved on the circumferential side of the roller. The left side of the bottom of the transmission belt is fixedly connected to the take-up reel.

5. The equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes according to claim 4, characterized in that, A horizontal plate is fixedly installed on the inner side of the support frame and at the top of the mixing vessel. A liquid inlet mechanism is fixedly installed at the top of the horizontal plate. The liquid inlet mechanism includes a sliding seat fixedly installed at the top of the horizontal plate. A moving tube is slidably connected inside the sliding seat. The left side of the top of the transmission belt is fixedly connected to the right side of the moving tube. A liquid inlet pipe is connected to the bottom of the sliding seat. A through groove is opened at the bottom of the moving tube and inside the sliding seat. A connecting plate is fixedly installed on the left side of the moving tube. A sliding rod is fixedly installed on the inner side of the top of the connecting plate. The right end of the sliding rod passes through the left side of the sliding seat and extends to the inner side of the sliding seat. A return spring is sleeved on the circumferential side of the sliding rod.

6. The equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes according to claim 5, characterized in that, After the moving tube moves a certain distance to the right inside the sliding seat, it will be in communication with the liquid inlet tube. Sealing gaskets are provided on both sides of the sliding seat.

7. The equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes according to claim 5, characterized in that, The inside of the vessel lid is vertically rotatably connected to a mixing mechanism, which includes a mixing shaft vertically rotatably connected to the inside of the vessel lid. Multiple sets of mixing paddles are fixed on the circumferential side of the mixing shaft and inside the mixing vessel. A mixing motor for driving the mixing shaft to rotate is provided on the top of the horizontal plate.

8. The equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathodes according to claim 1, characterized in that, The top of the support frame is fixed with two sets of fixed seats, and the top of each set of fixed seats is equipped with a storage tank. The bottom of the support frame is fixed with a base. The left side of the mixing vessel is connected to a liquid addition pipe, and the bottom of the mixing vessel is connected to a discharge pipe.

9. A process for co-processing aluminum ash from aluminum electrolysis with waste carbon cathodes to recover aluminum, characterized in that, Includes the following steps: Step S1: Crush, grind, sieve, and dry the aluminum electrolysis ash and waste carbon cathode respectively; Step S2: Stir the dried aluminum ash with water to remove chloride salts and hydrolyze aluminum nitride into aluminum hydroxide. Separate the solid and liquid to obtain filtrate A and filter residue A. Step S3: Stir the filter residue A with sulfuric acid solution to react and separate the solid and liquid to obtain filtrate B rich in aluminum sulfate and filter residue B containing α-alumina and magnesium aluminum spinel; Step S4: Stir the filter residue B with sodium hydroxide solution to further extract components such as aluminum nitride and aluminum oxide. Separate the solid and liquid to obtain filtrate C and filter residue C. Filter residue C can be used as a building material after multiple water washings. Step S5: Mix the dried cathode carbon block with filtrate B and react them. Separate the solid and liquid components to obtain fluorine-rich filtrate D and filter residue D. Step S6: Mix filter residue D and filtrate C and react them. Then, leach them twice and separate the solid and liquid to obtain filtrate E and filter residue E. Filter residue E is washed with water multiple times to obtain high-purity carbon blocks. Step S7: Mix filtrate B, filtrate C, filtrate D and filtrate E at an F / Al molar ratio, adjust the pH to 5.5-6.5 to react and generate aluminum hydroxy fluoride precursor. Separate the solid and liquid to obtain filtrate F and filter residue F. After calcining the filter residue F, obtain industrial-grade aluminum fluoride. When mixing and adjusting the pH, it needs to be completed in the equipment for co-processing and recovering aluminum from aluminum electrolysis ash and waste carbon cathode as described in any one of claims 1-8. Step S8: Mix filtrate F with filtrate A, and evaporate and concentrate to obtain sodium sulfate.

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