A device and method for extracting lithium from overhauled slag based on solid waste resource

Abstract

The application provides a kind of overhauling slag lithium extraction device and method based on solid waste resource, relating to solid waste treatment technical field, including extraction tank, temperature rising seat, side frame, mixing tank, driving mechanism and mixing mechanism;The extraction tank is installed in the inner wall of temperature rising seat in a through manner, the side frame is fixed to the side wall of extraction tank, and the mixing tank is installed in the inside of side frame in a through manner;The first top cover is sealingly installed on the top of extraction tank, the mounting bracket is fixed to the top of first top cover, and the driving mechanism includes support seat, motor and driving gear.The scheme mixes sulfuric acid and phosphoric acid uniformly in the mixing tank first, then adds extraction tank and transformation slag for reaction, optimizes the subsequent leaching effect by adjusting the acid liquid state in advance, mixes the acid in the mixing tank in advance, evenly disperses the heat by stirring, and then adds the extraction tank after the system temperature drops to room temperature or the process set temperature, so that the leaching process can be carried out at a stable temperature, and the workers can work in a safe environment.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment, and in particular to a lithium extraction device and method based on the resource utilization of solid waste from overhaul slag. Background Technology

[0002] Electrolytic aluminum overhaul slag is a solid waste removed from the electrolytic aluminum industry when production equipment reaches the end of its service life and undergoes major overhaul operations. It is one of the typical hazardous wastes in the electrolytic aluminum industry and must be treated and disposed of in strict accordance with environmental protection regulations.

[0003] Although electrolytic aluminum overhaul slag belongs to smelting slag, it is classified as hazardous waste due to the presence of highly toxic cyanide and high-value lithium and fluorine. Traditional disposal methods, such as landfilling, result in resource waste and environmental pollution. Therefore, it is necessary to carry out harmless treatment and high-value recovery methods for electrolytic aluminum overhaul slag, especially to achieve targeted separation and productization of lithium and fluorine through specific roasting transformation and acid leaching processes.

[0004] In existing technologies, when extracting lithium from the slag of electrolytic aluminum overhaul, sulfuric acid combined with phosphoric acid is used to extract lithium from the transition slag. In the extraction process, traditional methods generally involve directly adding the slag into the transition slag, which can easily cause violent reactions and has poor safety, making it inconvenient for users to operate the extraction in a safe environment.

[0005] Therefore, it is necessary to provide a lithium extraction device and method based on solid waste resource utilization to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a lithium extraction device and method based on solid waste resource utilization from overhaul slag, which solves the problem of dangerous acid leaching caused by violent reaction with transformation slag during traditional acid leaching.

[0007] To solve the above-mentioned technical problems, the present invention provides a lithium extraction device for overhaul slag based on solid waste resource utilization, including an extraction tank, a heating base, a side frame, a mixing tank, a drive mechanism, and a mixing mechanism;

[0008] The extraction tank is installed through the inner wall of the heating base, the side frame is fixed to the side wall of the extraction tank, and the mixing tank is installed through the inside of the side frame.

[0009] The extraction tank is sealed with a first top cover, and a mounting bracket is fixedly mounted on the top of the first top cover. The driving mechanism includes a support base, a motor, and a drive gear. The support base is fixed on the upper surface of the first top cover and located inside the mounting bracket. The motor is mounted on the upper surface of the support base. The drive gear is keyway connected to the output shaft of the motor. A driven gear is meshed with one side of the drive gear. A central shaft is keyway connected to the shaft of the driven gear. A limiting plate is fixedly mounted on the top of the mounting bracket. A first ratchet is keyway connected to the top of the central shaft. A first ratchet sleeve is meshed with the outer wall of the first ratchet. A drive pulley is fixedly mounted at the bottom of the first ratchet sleeve.

[0010] The mixing tank is sealed with a second top cover. The mixing mechanism includes a driven pulley and a first belt. The driven pulley is rotatably connected to the top of the second top cover. The first belt is sleeved on the outer wall of the drive pulley and the driven pulley. A mixing rod and a rotating ring are connected by a keyway at the axis of the driven pulley and inside the mixing tank. Three arc-shaped racks are fixed on the outer wall of the rotating ring. Two mounting plates are fixed on the inner wall of the mixing tank. A rotating gear is installed above each of the two mounting plates. A hose is installed on the top of each of the two rotating gears.

[0011] Preferably, the first ratchet shaft is rotatably connected to the limiting plate, and the drive pulley is rotatably connected to the mounting bracket.

[0012] Preferably, the first ratchet sleeve and the drive pulley are hollow at their shaft center and do not contact the central shaft, which passes through the shaft center of the drive pulley and the first ratchet sleeve.

[0013] Preferably, the three arc-shaped racks are equidistantly distributed in a ring about the center of the rotating ring, and the arc-shaped racks and the rotating gear mesh with each other.

[0014] Preferably, a sleeve is installed inside the mounting plate, and a "T"-shaped positioning rod is rotatably installed inside the sleeve. A torsion spring is sleeved on the outer wall of the positioning rod and located inside the sleeve. The axis of the rotating gear is connected to the axis of the positioning rod via a keyway.

[0015] Preferably, it also includes a material distribution mechanism;

[0016] The bottom keyway of the central shaft is connected to a second ratchet, the outer wall of the second ratchet is fitted with a second ratchet sleeve, and the bottom of the second ratchet sleeve is fixed with a first pulley.

[0017] The material distribution mechanism includes a second pulley rotatably mounted on the upper surface of the first top cover. A second belt is sleeved on the outer wall of the first pulley and the second pulley. A stirring rod is connected to the axis of the first pulley and the inside of the extraction tank via a keyway. A rotating rod is connected to the axis of the second pulley and the side of the stirring rod via a keyway. A material distribution plate is fixed on the outer wall of the rotating rod. A discharge frame is fixed on the side wall of the material distribution plate. A liquid outlet pipe is fixed on the side wall of the mixing tank.

[0018] Preferably, the outer walls of the stirring rod and the rotating rod are rotatably connected to the first top cover, and the liquid outlet pipe passes through the inside of the extraction tank and extends to the upper surface of the distribution plate.

[0019] Preferably, an "L"-shaped sampling tube is installed inside the extraction tank and below the liquid outlet pipe, a rotating blade is fixed at the bottom end of the rotating rod, a feed pipe is installed on the upper side wall of the extraction tank, and a discharge pipe is installed at the bottom end of the extraction tank.

[0020] The lithium extraction method based on overhaul slag from solid waste resource utilization includes the following steps:

[0021] S1: Preprocessing;

[0022] The overhaul slag is crushed to 100-200 mesh using a jaw crusher and then screened to obtain uniform carbon slag powder.

[0023] Primary roasting: Oxygen or inert gas is introduced into a tube furnace, and the temperature is raised to 500-800℃ at a rate of 8-12℃ / min and held for 1.5-3 hours. The roasted material is light gray, with minimal loss of fluorine and lithium, promoting carbon removal, and achieving a cyanide decomposition rate of >99.8%.

[0024] Secondary roasting: The roasting residue is mixed with calcium hydroxide and calcium sulfate in a mass ratio of 15:2:1 and roasted in a muffle furnace at 400-900℃ for 0.5-2 hours to form soluble lithium salt and CaF2;

[0025] S2: Lithium extraction by acid leaching;

[0026] The transformation residue is leached with a mixture of 60-98wt% sulfuric acid and 30-50wt% phosphoric acid at 75-90℃ for 2 hours, followed by filtration and testing. This step needs to be carried out in the extraction tank during acid leaching for lithium extraction.

[0027] S3: Lithium immersion refining;

[0028] The pH of the leachate was adjusted to 12 by adding CaO suspension, and Al and Fe impurities were removed by filtration. 1-1.5 times the stoichiometric ratio of trisodium phosphate was added, and the mixture was reacted at 60-80℃ for 1 hour. After aging, it was washed three times with hot water at 90℃ and dried to obtain battery-grade lithium phosphate.

[0029] S4: Preparation of aluminum fluoride;

[0030] After the acid leaching residue is cleaned with 0.3-0.8 mol / L hydrochloric acid, it is mixed with Al2O3 at an Al / F molar ratio of 1:3 and then smelted in a muffle furnace at 600-900℃ for 1 hour to obtain aluminum fluoride.

[0031] Compared with related technologies, the lithium extraction device and method based on solid waste resource utilization provided by this invention have the following beneficial effects:

[0032] In the process of lithium extraction by leaching, sulfuric acid and phosphoric acid are first mixed evenly in a mixing tank, and then added to the extraction tank to react with the transformation residue. By adjusting the acid state in advance, the subsequent leaching effect is optimized. Stirring is used to make the two acids form a uniform concentration mixture system. After being added to the extraction tank, it can be evenly contacted with the transformation residue, ensuring that every residue particle is in the optimal reaction acid concentration environment and reducing local imbalance problems.

[0033] Pre-mixing the acid in the mixing tank allows for even heat distribution through stirring. The acid is then added to the extraction tank after the system temperature has dropped to room temperature or the process set temperature, ensuring that the leaching process is carried out at a stable temperature and that workers can work in a safe environment. Attached Figure Description

[0034] 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.

[0035] Figure 1 The optimal structural schematic diagram provided for this invention;

[0036] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the extraction tank and the mixing tank.

[0037] Figure 3 for Figure 2 The diagram shows the structure viewed from below.

[0038] Figure 4 for Figure 1 The diagram shows a detailed structural schematic of the drive mechanism.

[0039] Figure 5 for Figure 4 The enlarged structural diagram at point A is shown below;

[0040] Figure 6 for Figure 5 The schematic diagram shows the cross-sectional structure of the mounting bracket, the first ratchet sleeve, and the drive pulley.

[0041] Figure 7 for Figure 6 The diagram shows the structure viewed from below.

[0042] Figure 8 A detailed structural diagram of the hybrid mechanism provided by the present invention;

[0043] Figure 9 for Figure 8 The enlarged structural diagram at point B is shown below;

[0044] Figure 10 Figure 8 The schematic diagram shows the cross-sectional structure of the mounting plate and sleeve.

[0045] Figure 11 The present invention provides a schematic diagram of the working state of the hybrid mechanism, wherein (a) is a schematic diagram of the initial working state of the two hoses, (b) is a schematic diagram of the working state of controlling the rotation of one hose when the arc rack rotates, and (c) is a schematic diagram of the working state of controlling the rotation of the other hose when the arc rack continues to rotate.

[0046] Figure 12 A schematic diagram showing the location distribution of the material distribution mechanism and the liquid outlet pipe provided by the present invention;

[0047] Figure 13 This is a flowchart of a lithium extraction method based on overhaul slag from solid waste resource utilization.

[0048] Figure 14 XRD pattern of lithium phosphate;

[0049] Figure 15 The image shows the xrd plot of aluminum fluoride.

[0050] Explanation of icon numbers:

[0051] 1. Extraction tank; 2. Heating base; 3. First top cover;

[0052] 4. Side frame; 5. Mixing tank;

[0053] 6. Mixing mechanism; 61. Driven pulley; 62. First belt; 63. Mixing rod; 64. Rotary ring; 65. Arc rack; 66. Discharge pipe; 67. Mounting plate; 68. Rotary gear; 69. Hose; 610. Sleeve; 611. Positioning rod; 612. Torsion spring.

[0054] 7. Drive mechanism; 71. Support base; 72. Motor; 73. Drive gear; 74. Driven gear; 75. Central shaft; 76. Limiting plate; 77. First ratchet; 78. First ratchet sleeve; 79. Drive pulley; 710. Second ratchet; 711. Second ratchet sleeve; 712. First pulley.

[0055] 8. Material distribution mechanism; 81. Second pulley; 82. Second belt; 83. Stirring rod; 84. Rotating rod; 85. Material distribution plate; 86. Discharge frame; 87. Rotating blade.

[0056] 9. Second top cover; 10. Sampling tube;

[0057] 11. Feed pipe, 12. Discharge pipe, 13. Mounting frame. Detailed Implementation

[0058] 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.

[0059] This invention provides a lithium extraction device and method based on the resource utilization of solid waste from overhaul slag.

[0060] First embodiment:

[0061] Please see Figures 1 to 11 A lithium extraction device based on overhaul slag for solid waste resource utilization includes an extraction tank 1, a heating base 2, a side frame 4, a mixing tank 5, a drive mechanism 7, and a mixing mechanism 6.

[0062] The extraction tank 1 is installed through the inner wall of the heating base 2, the side frame 4 is fixed to the side wall of the extraction tank 1, and the mixing tank 5 is installed through the inside of the side frame 4.

[0063] The extraction tank 1 is sealed with a first top cover 3. The top of the first top cover 3 is fixed with a mounting bracket 13. The drive mechanism 7 includes a support base 71, a motor 72, and a drive gear 73. The support base 71 is fixed on the upper surface of the first top cover 3 and located inside the mounting bracket 13. The motor 72 is mounted on the upper surface of the support base 71. The drive gear 73 is keyway connected to the output shaft of the motor 72. A driven gear 74 is meshed on one side of the drive gear 73. A central shaft 75 is keyway connected to the shaft center of the driven gear 74. A limiting plate 76 is fixed on the top of the mounting bracket 13. A first ratchet 77 is keyway connected to the top of the central shaft 75. A first ratchet sleeve 78 is meshed on the outer wall of the first ratchet 77. A drive pulley 79 is fixed on the bottom of the first ratchet sleeve 78.

[0064] The mixing tank 5 is sealed with a second top cover 9. The mixing mechanism 6 includes a driven pulley 61 and a first belt 62. The driven pulley 61 is rotatably connected to the top of the second top cover 9. The first belt 62 is sleeved on the outer wall of the drive pulley 79 and the driven pulley 61. The driven pulley 61 is connected to a mixing rod 63 and a rotating ring 64 via a keyway at its axis and inside the mixing tank 5. Three arc-shaped racks 65 are fixed on the outer wall of the rotating ring 64. Two mounting plates 67 are fixed on the inner wall of the mixing tank 5. A rotating gear 68 is mounted on the top of each of the two mounting plates 67. A hose 69 is mounted on the top of each of the two rotating gears 68.

[0065] The first ratchet 77 is rotatably connected to the limiting plate 76 at its shaft center, and the drive pulley 79 is rotatably connected to the mounting bracket 13.

[0066] The first ratchet sleeve 78 and the drive pulley 79 are hollow at their shaft center and do not contact the central shaft 75, which passes through the shaft center of the drive pulley 79 and the first ratchet sleeve 78.

[0067] The three arc-shaped racks 65 are equidistantly distributed in a ring about the axis of the rotating ring 64, and the arc-shaped racks 65 and the rotating gear 68 mesh with each other.

[0068] A sleeve 610 is installed inside the mounting plate 67. A "T"-shaped positioning rod 611 is rotatably installed inside the sleeve 610. A torsion spring 612 is sleeved on the outer wall of the positioning rod 611 and inside the sleeve 610. The axis of the rotating gear 68 is connected to the axis of the positioning rod 611 via a keyway.

[0069] Please see Figure 4 and Figure 5 The motor 72 can preferably be a three-phase asynchronous motor. When the user starts the motor 72, it controls the drive gear 73 to mesh with the driven gear 74 to rotate. The driven gear 74 can control the central shaft 75 to rotate clockwise or counterclockwise. First, the central shaft 75 rotates clockwise, which synchronously controls the first ratchet 77 to rotate clockwise. When the first ratchet 77 rotates clockwise, it meshes and controls the first ratchet sleeve 78 to drive the drive pulley 79 to rotate clockwise synchronously.

[0070] Please see Figure 4 and Figure 8 Therefore, the clockwise rotating drive pulley 79 drives the first belt 62 to control the rotation of the driven pulley 61. When the driven pulley 61 rotates, it can control the rotating ring 64 and the mixing rod 63 to rotate clockwise in the mixing tank 5.

[0071] Please see Figure 8 and Figure 9Users can install sulfuric acid and phosphoric acid conveying devices on the outside of the two hoses 69 respectively to convey sulfuric acid and phosphoric acid to the inside of the mixing tank 5 through the two hoses 69.

[0072] Please see Figure 11 In (a): In the initial state, the two hoses 69 deliver sulfuric acid and phosphoric acid in a fixed-point manner;

[0073] Please see Figure 11 (b) In this context: When the rotating ring 64 drives the arc rack 65 to rotate, the rotating arc rack 65 will mesh with the rotating gear 68 to drive the hose 69 to rotate and form a fan-shaped motion trajectory to spray and deliver sulfuric acid or phosphoric acid. At this time, the other rotating gear 68 cannot contact the arc rack 65, so it still maintains fixed-point delivery.

[0074] Please see Figure 11 (c): As the rotating ring 64 continues to rotate, when the arc-shaped rack 65 and the rotated gear 68 separate, the rotating gear 68 will automatically reset because they cannot mesh. When the upper arc-shaped rack 65 rotates to the position of the rotating gear 68, the rotating gear 68 can be combined with the control of the rotating gear 68 to drive the hose 69 to form a fan-shaped rotating trajectory to spray sulfuric acid or phosphoric acid.

[0075] Understandable: See Figure 10 It can be seen that since the rotating gear 68 rotates inside the sleeve 610 through the positioning rod 611, and during the rotation, the torsion spring 612 is set. The top of the torsion spring 612 is restricted by the top of the sleeve 610, and the bottom of the torsion spring 612 is restricted by the positioning rod 611. When the rotating gear 68 is affected by the meshing force, the torsion spring 612 can be forced to twist. When the rotating gear 68 loses the meshing force, the torsion spring 612 can control the rotating gear 68 to automatically return to the initial state.

[0076] Preferably, the hose 69 for conveying sulfuric acid and phosphoric acid can be a corrosion-resistant fluoroplastic hose 69.

[0077] Please see Figure 6 and Figure 7 Since the central shaft 75 does not contact the first ratchet sleeve 78 and the drive pulley 79, the central shaft 75 can independently control the rotation of the first ratchet 77 without causing interference with the first ratchet sleeve 78 and the drive pulley 79.

[0078] This embodiment:

[0079] During the lithium leaching process, sulfuric acid and phosphoric acid are first mixed evenly in mixing tank 5, and then added to extraction tank 1 to react with the transformation residue. By adjusting the acid state in advance, the subsequent leaching effect is optimized. Stirring is used to make the two acids form a uniform concentration mixture system. After being added to extraction tank 1, it can be in uniform contact with the transformation residue, ensuring that every residue particle is in the optimal reaction acid concentration environment and reducing local imbalance problems.

[0080] The acid is mixed in the mixing tank 5 in advance. The heat can be evenly distributed by stirring. After the system temperature drops to room temperature or the process set temperature, it is added to the extraction tank 1 to ensure that the leaching process is carried out at a stable temperature and that the staff can work in a safe environment.

[0081] Acid leaching of lithium from the slag of electrolytic aluminum overhaul is a rational use of smelting slag, which effectively avoids the generation of solid waste, is conducive to resource integration and utilization, and is more environmentally friendly.

[0082] Secondly, the use of a rotating gear 68 to control the hose 69 for material feeding maximizes the control of the acid contact area, achieves instantaneous uniform dispersion, and shortens the mixing time of sulfuric acid and phosphoric acid. If the exothermic reaction of sulfuric acid and phosphoric acid is concentrated in a local area, it may still lead to a small-scale high temperature. The local high temperature may still affect the ionic state of the acid. The design of the fan-shaped spray trajectory can disperse the exothermic source and alleviate the problem of local high temperature.

[0083] Second embodiment:

[0084] Please see Figures 2 to 5 , Figure 8 and Figure 12 It also includes a material distribution mechanism 8;

[0085] The bottom keyway of the central shaft 75 is connected to a second ratchet 710, and a second ratchet sleeve 711 is sleeved on the outer wall of the second ratchet 710. A first pulley 712 is fixedly installed at the bottom of the second ratchet sleeve 711.

[0086] The material distribution mechanism 8 includes a second pulley 81 rotatably mounted on the upper surface of the first top cover 3. A second belt 82 is sleeved on the outer wall of the first pulley 712 and the second pulley 81. A stirring rod 83 is connected to the axis of the first pulley 712 and the keyway inside the extraction tank 1. A rotating rod 84 is connected to the axis of the second pulley 81 and the keyway on one side of the stirring rod 83. A material distribution plate 85 is fixed on the outer wall of the rotating rod 84. A discharge frame 86 is fixed on the side wall of the material distribution plate 85. A liquid outlet pipe 66 is fixed on the side wall of the mixing tank 5.

[0087] The outer walls of the stirring rod 83 and the rotating rod 84 are rotatably connected to the first top cover 3, and the liquid outlet pipe 66 passes through the inside of the extraction tank 1 and extends to the upper surface of the distribution plate 85.

[0088] Please see Figure 4 and Figure 5 In the first embodiment, when the central shaft 75 rotates clockwise, the central shaft 75 will drive the first ratchet 77 to control the first ratchet sleeve 78 to rotate. Although the second ratchet 710 will rotate clockwise, it will not control the second ratchet sleeve 711 to rotate. Therefore, in the first embodiment, the entire second ratchet sleeve 711 and the first pulley 712 are stopped working.

[0089] Conversely, if the central shaft 75 rotates counterclockwise, the first ratchet 77 will not control the first ratchet sleeve 78 to rotate, while the second ratchet 710 will rotate counterclockwise to control the second ratchet sleeve 711 to control the first pulley 712 to rotate, thus automatically disengaging the mixing mechanism 6.

[0090] When the first pulley 712 rotates, it can drive the second belt 82 to control the rotation of the second pulley 81. The rotation of the first pulley 712 and the second pulley 81 can control the rotation of the stirring rod 83 and the rotating rod 84.

[0091] Please see Figure 4 and Figure 3 The stirring rod 83 can rotate inside the extraction tank 1. By rotating the stirring rod 83, the transformation residue and sulfuric acid-phosphoric acid mixture in the extraction tank 1 can be fully stirred and leached to extract lithium.

[0092] Please see Figure 12 During the rotation of the rotating rod 84, the material distribution plate 85 and the discharge frame 86 will rotate synchronously. At this time, the sulfuric acid and phosphoric acid mixture in the mixing tank 5 will be guided to the material distribution plate 85 through the liquid outlet pipe 66, and then evenly distributed from the material distribution plate 85 to the discharge frame 86 in the extraction tank 1 and mixed with the transformation residue.

[0093] This embodiment:

[0094] The sulfuric acid-phosphoric acid mixture covers the surface of the slag in a dispersed state and even penetrates into the pores inside the slag particles, which can maximize the contact area between the acid and the lithium-containing substances and avoid the residue of unreacted slag nuclei due to insufficient local acid content.

[0095] Dispersed contact can reduce the liquid film resistance of acid on the slag surface, and at the same time promote the rapid detachment of generated lithium elements from the slag into the liquid phase, significantly shortening the lithium dissolution reaction time and improving the lithium recovery rate within the effective time.

[0096] At the same time, it can stably control the pH. The pH of the mixture of sulfuric acid and phosphoric acid needs to be stable within a specific range. By using dispersion and distribution, it can avoid the local concentration of mixed acid and the resulting sudden drop in pH. It can also prevent amphoteric metals such as aluminum and iron from excessively dissolving in a strong acid environment, while maintaining the overall pH stability of the system.

[0097] Third embodiment:

[0098] Please see Figure 3and Figure 12 An "L"-shaped sampling tube 10 is installed inside the extraction tank 1 and below the liquid outlet pipe 66. A rotating blade 87 is fixed at the bottom end of the rotating rod 84. A feed pipe 11 is installed on the upper side wall of the extraction tank 1, and a discharge pipe 12 is installed at the bottom end of the extraction tank 1.

[0099] Please see Figure 3 and Figure 12 Since the sampling tube 10 is located at the bottom of the rotating blade 87, during the operation of the second embodiment, the rotating rod 84 drives the rotating blade 87 to rotate on the sampling tube 10 in sync. When the rotating blade 87 rotates on the upper liquid surface, it can treat the surface foam.

[0100] This embodiment:

[0101] During the stirring leaching process, a rotating blade 87 is installed to break up the foam through mechanical shearing force, allowing the liquid in the foam to flow back into the main body of the leachate. Solid impurities settle down after being broken up with the foam. Finally, only the pure liquid phase leachate is collected during sampling, ensuring that the sample composition is completely consistent with the liquid phase composition of the overall leachate in the tank. After the rotating blade 87 removes the foam, the liquid surface returns to a flat single-phase liquid state, and the sampling tube 10 can directly contact the pure liquid phase. Whether it is volume measurement or mass measurement, it can accurately match the preset sampling amount, eliminating deviations from the measurement stage.

[0102] Fourth embodiment:

[0103] Please see Figures 13 to 15 A lithium extraction method based on overhaul slag from solid waste resource utilization includes the following steps:

[0104] S1: Preprocessing;

[0105] The overhaul slag is crushed to 100-200 mesh using a jaw crusher and then screened to obtain uniform carbon slag powder.

[0106] Primary roasting: Oxygen or inert gas is introduced into a tube furnace, and the temperature is raised to 500-800℃ at a rate of 8-12℃ / min and held for 1.5-3 hours. The roasted material is light gray, with minimal loss of fluorine and lithium, promoting carbon removal, and a cyanide decomposition rate of >99.8%.

[0107] Secondary roasting: The roasting residue is mixed with calcium hydroxide and calcium sulfate in a mass ratio of 15:2:1 and roasted in a muffle furnace at 400-900℃ for 0.5-2 hours to form soluble lithium salt and CaF2;

[0108] S2: Lithium extraction by acid leaching;

[0109] The transformation residue is leached with a mixture of 60-98wt% sulfuric acid and 30-50wt% phosphoric acid at 75-90℃ for 2 hours, followed by filtration and testing. This step needs to be carried out in extraction tank 1 during acid leaching for lithium extraction. The lithium leaching rate of the leaching solution is ≥95%; the acid leaching residue has a CaF2 content >90% and a fluorine leaching rate <5%.

[0110] S3: Lithium immersion refining;

[0111] The pH of the leachate was adjusted to 12 by adding CaO suspension, and Al and Fe impurities were removed by filtration. 1-1.5 times the stoichiometric ratio of trisodium phosphate was added, and the mixture was reacted at 60-80℃ for 1 hour. After aging, it was washed three times with hot water at 90℃ and dried to obtain battery-grade lithium phosphate.

[0112] S4: Preparation of aluminum fluoride;

[0113] After the acid leaching residue is cleaned with 0.3-0.8 mol / L hydrochloric acid, it is mixed with Al2O3 at an Al / F molar ratio of 1:3 and then smelted in a muffle furnace at 600-900℃ for 1 hour to obtain aluminum fluoride.

[0114] Existing lithium extraction technologies have significant drawbacks:

[0115] 1. Incomplete removal of cyanide: Conventional pyrolysis at 600℃ has a decomposition rate of <90%, leaving residual cyanide contaminating the product;

[0116] 2. Low lithium recovery rate: Direct acid leaching leads to a large amount of fluorine leaching (>20%), resulting in HF corrosion of the equipment, and the lithium leaching rate is <80%.

[0117] 3. Unutilized fluorine resources: The fluorine content of acid leaching residue is >40%, but existing technologies have not achieved targeted conversion.

[0118] This embodiment:

[0119] The process employs a two-stage roasting synergistic effect: primary oxygen roasting destroys cyanide ions and promotes carbon removal; secondary calcification roasting converts lithium to CaLi2(SO4)2 and fluorine to CaF2; and phosphoric acid controls fluorine production through the reaction of phosphate ions with dissolved Al. 3+ An AlPO4 film is generated to encapsulate calcium fluoride particles, inhibiting fluorine dissolution. Gradient lithium precipitation technology is used for pre-removal of impurities to avoid lithium phosphate precipitation carrying impurities.

[0120] Please refer to the reference again. Figures 1 to 12 The working principle of the lithium extraction device and method based on solid waste resource utilization provided by this invention is as follows:

[0121] Step S1: Preparation of a mixed acid of sulfuric acid and phosphoric acid;

[0122] The starter motor 72 controls the drive gear 73 to mesh and drive the driven gear 74 to rotate. First, the central shaft 75 rotates clockwise, which synchronously controls the first ratchet 77 to rotate clockwise. When the first ratchet 77 rotates clockwise, the meshing effect controls the first ratchet sleeve 78 to drive the drive pulley 79 to rotate clockwise synchronously. The clockwise rotating drive pulley 79 drives the first belt 62 to control the driven pulley 61 to rotate. When the driven pulley 61 rotates, it can control the rotating ring 64 and the mixing rod 63 to rotate clockwise in the mixing tank 5.

[0123] Sulfuric acid and phosphoric acid conveying devices are installed on the outside of the two hoses 69 respectively to convey sulfuric acid and phosphoric acid to the inside of the mixing tank 5 through the two hoses 69. When the rotating ring 64 rotates, it drives the arc rack 65 to rotate, and controls the rotating gear 68 to control the movement of the hoses 69 to inject sulfuric acid and phosphoric acid into the inside of the mixing tank 5.

[0124] Step S2, lithium extraction by acid leaching;

[0125] Users can install valves on the outlet pipe 66. Rotating the valves causes the outlet pipe 66 to inject the mixed acid in the mixing tank 5 into the distribution plate 85. When the user controls the central shaft 75 to rotate counterclockwise, the first ratchet 77 will not control the first ratchet sleeve 78 to rotate, while the second ratchet 710 will rotate counterclockwise to control the second ratchet sleeve 711 to control the first pulley 712 to rotate. When the first pulley 712 rotates, it can drive the second belt 82 to control the second pulley 81 to rotate. The rotation of the first pulley 712 and the second pulley 81 can control the rotation of the stirring rod 83 and the rotating rod 84. During the leaching process, the heating seat 2 is activated to heat and leach the extract tank 1. The feed pipe 11 is used for the transformation residue discharge, and the discharge pipe 12 is used for the leachate discharge.

[0126] 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 lithium extraction device based on overhaul slag from solid waste resource utilization, characterized in that, Includes extraction tank, heating base, side frame, mixing tank, drive mechanism and mixing mechanism; The extraction tank is installed through the inner wall of the heating base, the side frame is fixed to the side wall of the extraction tank, and the mixing tank is installed through the inside of the side frame. The extraction tank is sealed with a first top cover, and a mounting bracket is fixedly mounted on the top of the first top cover. The driving mechanism includes a support base, a motor, and a drive gear. The support base is fixed on the upper surface of the first top cover and located inside the mounting bracket. The motor is mounted on the upper surface of the support base. The drive gear is keyway connected to the output shaft of the motor. A driven gear is meshed with one side of the drive gear. A central shaft is keyway connected to the shaft of the driven gear. A limiting plate is fixedly mounted on the top of the mounting bracket. A first ratchet is keyway connected to the top of the central shaft. A first ratchet sleeve is meshed with the outer wall of the first ratchet. A drive pulley is fixedly mounted at the bottom of the first ratchet sleeve. The mixing tank is sealed with a second top cover. The mixing mechanism includes a driven pulley and a first belt. The driven pulley is rotatably connected to the top of the second top cover. The first belt is sleeved on the outer wall of the drive pulley and the driven pulley. A mixing rod and a rotating ring are connected by a keyway at the axis of the driven pulley and inside the mixing tank. Three arc-shaped racks are fixed on the outer wall of the rotating ring. Two mounting plates are fixed on the inner wall of the mixing tank. Rotary gears are installed above the two mounting plates. Flexible hoses are installed on the top of the two rotating gears. The first ratchet shaft is rotatably connected to the limiting plate, and the drive pulley is rotatably connected to the mounting bracket; The first ratchet sleeve and the drive pulley have a hollow design at their shaft center and do not contact the central shaft, which passes through the shaft center of the drive pulley and the first ratchet sleeve. The three arc-shaped racks are equidistantly distributed in a ring about the center of the rotating ring, and the arc-shaped racks and the rotating gear mesh with each other; A sleeve is installed inside the mounting plate, and a "T"-shaped positioning rod is rotatably installed inside the sleeve. A torsion spring is sleeved on the outer wall of the positioning rod and inside the sleeve. The axis of the rotating gear is connected to the axis of the positioning rod via a keyway. It also includes a material distribution mechanism; The bottom keyway of the central shaft is connected to a second ratchet, the outer wall of the second ratchet is fitted with a second ratchet sleeve, and the bottom of the second ratchet sleeve is fixed with a first pulley. The material distribution mechanism includes a second pulley rotatably mounted on the upper surface of the first top cover. A second belt is sleeved on the outer wall of the first pulley and the second pulley. A stirring rod is connected to the axis of the first pulley and the inside of the extraction tank via a keyway. A rotating rod is connected to the axis of the second pulley and the side of the stirring rod via a keyway. A material distribution plate is fixed on the outer wall of the rotating rod. A discharge frame is fixed on the side wall of the material distribution plate. A liquid outlet pipe is fixed on the side wall of the mixing tank.

2. The lithium extraction device based on solid waste resource utilization from overhaul slag according to claim 1, characterized in that, The outer walls of the stirring rod and the rotating rod are rotatably connected to the first top cover, and the liquid outlet pipe passes through the inside of the extraction tank and extends to the upper surface of the distribution plate.

3. The lithium extraction device based on solid waste resource utilization from overhaul slag according to claim 1, characterized in that, An "L"-shaped sampling tube is installed inside the extraction tank and below the liquid outlet pipe. A rotating blade is fixed at the bottom end of the rotating rod. A feed pipe is installed on the upper side wall of the extraction tank, and a discharge pipe is installed at the bottom end of the extraction tank.

4. A lithium extraction method based on overhaul slag from solid waste resource utilization, characterized in that, The lithium extraction method based on overhaul slag from solid waste resource utilization includes the lithium extraction device based on overhaul slag from solid waste resource utilization as described in any one of claims 1-3, and includes the following steps: S1: Preprocessing; The overhaul slag is crushed to 100-200 mesh using a jaw crusher and then screened to obtain uniform carbon slag powder. Primary roasting: Oxygen or inert gas is introduced into a tube furnace, and the temperature is raised to 500-800℃ at a rate of 8-12℃ / min and held for 1.5-3 hours. The roasted material is light gray, with no loss of fluorine and lithium, promoting carbon removal, and a cyanide decomposition rate of >99.8%. Secondary roasting: The roasting residue is mixed with calcium hydroxide and calcium sulfate in a mass ratio of 15:2:1 and roasted in a muffle furnace at 400-900℃ for 0.5-2 hours to form soluble lithium salt and CaF2; S2: Lithium extraction by acid leaching; The transformation residue is leached with a mixture of 60-98wt% sulfuric acid and 30-50wt% phosphoric acid at 75-90℃ for 2 hours, followed by filtration and testing. This step needs to be carried out in the extraction tank during acid leaching for lithium extraction. S3: Lithium immersion refining; The pH of the leachate was adjusted to 12 by adding CaO suspension, and Al and Fe impurities were removed by filtration. 1-1.5 times the stoichiometric ratio of trisodium phosphate was added, and the mixture was reacted at 60-80℃ for 1 hour. After aging, it was washed three times with hot water at 90℃ and dried to obtain battery-grade lithium phosphate. S4: Preparation of aluminum fluoride; After the acid leaching residue is cleaned with 0.3-0.8 mol / L hydrochloric acid, it is mixed with Al2O3 at an Al / F molar ratio of 1:3 and then smelted in a muffle furnace at 600-900℃ for 1 hour to obtain aluminum fluoride.

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