Sewage treatment equipment and process for lithium extraction by low-temperature calcination of lepidolite

Abstract

This invention provides a wastewater treatment device and process for lithium extraction from lithium mica at low temperature, relating to the field of wastewater treatment technology. The device includes an equalization tank, a reciprocating scraping mechanism, a sampling mechanism, and a buffer mechanism. The reciprocating scraping mechanism includes two mounting frames, each with a rotating rod longitudinally rotatably connected to its inner side. Each rotating rod has a pulley fixed to its circumferential side. This design ultimately achieves the goal of using the reciprocating frame to drive the scraper to the right, pushing the foam generated during the treatment of fluoride-containing wastewater into a collection tank for discharge. This avoids the foam carrying solid particles, preventing calcium fluoride and other particles from floating, reducing wastewater sedimentation efficiency, and improving wastewater treatment effectiveness. When the reciprocating frame moves to the right, it simultaneously drives the drive plate to the right. Through the cooperation of the rotating wheel and the moving support, a sampling cup is used to sample the foam, accurately capturing core components such as calcium fluoride particles and surfactants carried within it.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and in particular to a wastewater treatment equipment and process for lithium extraction from lithium mica by low-temperature roasting. Background Technology

[0002] In the lithium extraction process from lepidolite, the addition of calcium chloride as an additive is a crucial process for controlling fluoride pollution. Its core function is to efficiently convert the volatile fluoride in the mineral structure into chemically stable calcium fluoride during the roasting stage, thereby eliminating the generation of highly toxic and corrosive hydrogen fluoride gas at its source. However, calcium fluoride dissolves in water in trace amounts, and the leaching residue contains a very small amount of incompletely fixed soluble fluoride. Therefore, the washing water from the leaching residue contains a certain concentration of fluoride ions, constituting fluoride-containing wastewater that must be treated.

[0003] In related technologies, during the lithium extraction process from lepidolite, the leaching residue washing water contains a certain concentration of fluoride ions, which needs to be treated before discharge. However, in existing wastewater treatment equipment, the addition of lime slurry during fluoride removal raises the pH of the wastewater to an alkaline range. In an alkaline environment, trace amounts of oils, fats, and residual chemicals in the wastewater may undergo a "saponification" reaction or change form, transforming into surface-active substances that form foam on the water surface. Existing wastewater treatment equipment is not convenient for removing and sampling the foam on the water surface. The foam can carry solid particles, causing particles such as calcium fluoride that should settle to float to the surface, reducing sedimentation efficiency. Furthermore, the foam is carried into subsequent reaction tanks or sedimentation tanks by the water flow, interfering with the treatment process and thus reducing the treatment effect on fluoride-containing wastewater.

[0004] Therefore, it is necessary to provide a wastewater treatment equipment and process for lithium extraction from lithium mica at low temperature to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a wastewater treatment equipment and process for lithium extraction from lithium mica at low temperature, which solves the problem that existing wastewater treatment equipment is not convenient for removing foam from the water surface and sampling at the same time, and for particles such as calcium fluoride to float up, reducing sedimentation efficiency.

[0006] To solve the above-mentioned technical problems, the wastewater treatment equipment for lithium extraction from low-temperature roasting of lepidolite provided by the present invention includes an equalization tank, a reciprocating scraping mechanism, a sampling mechanism, and a buffer mechanism.

[0007] The reciprocating scraping mechanism includes two mounting frames. A rotating rod is longitudinally rotatably connected to the inner side of each mounting frame. A pulley is fixed to the circumferential side of each rotating rod. A belt is fitted onto the surface of each pulley. Guide rails are fixed to the front and rear sides of the inner wall of the regulating tank. Rollers are installed inside each guide rail. A reciprocating frame is rotatably connected to the opposite side of each roller. The top of the belt is fixedly connected to the reciprocating frame. A drive motor for rotating the rotating rod is installed on the front of the left mounting frame. A scraper is fixed to the left side of the reciprocating frame by bolts.

[0008] The sampling mechanism includes a guide seat fixed to the rear side of the inner wall of the regulating tank. A slider is slidably connected to the surface of the guide seat. A movable bracket is fixed to the front of the slider. A rotating shaft is rotatably connected inside the movable bracket. A sampling cup is fixed to the front end of the rotating shaft. A rotating gear is fixed to the rear end of the rotating shaft. A rotating toothed plate is fixed to the rear side of the inner wall of the regulating tank. The rotating gear meshes with the rotating toothed plate. A rotating wheel is rotatably connected to the front of the movable bracket. A drive plate is fixed to the inner side of the reciprocating frame.

[0009] The buffer mechanism includes a mounting bracket fixed to the rear side of the top of the regulating pool. A sliding rod is vertically slidably connected inside the mounting bracket. The bottom end of the sliding rod is fixedly connected to the top of the movable bracket. A buffer spring is sleeved on the surface of the sliding rod and at the bottom of the mounting bracket.

[0010] Preferably, a collection trough is fixedly provided on the right side of the inner wall of the regulating pool, two discharge pipes are connected to the right side of the regulating pool, two protective frames are fixedly provided on the top of the regulating pool, two feed pipes are provided on the inner side of the front protective frame, and distance sensors are fixedly provided on both sides of the inner wall of the regulating pool.

[0011] Preferably, the inner side of the drive plate is provided with a drive groove, which consists of two straight grooves and one inclined groove, and is used in conjunction with the rotating wheel. The rotating toothed plate is composed of two tooth groups, which are located on the same vertical line and are separated from each other.

[0012] Preferably, a cleaning mechanism is fixedly provided on the inner side of the mounting bracket. The cleaning mechanism includes a storage cylinder fixed inside the mounting bracket. A movable frame is slidably connected inside the storage cylinder. A piston is fixedly provided at the top of the movable frame and inside the storage cylinder. A return spring is sleeved on the surface of the movable frame and at the bottom of the storage cylinder. A contact wheel is rotatably connected to the inner side of the movable frame.

[0013] Preferably, the top of the storage cylinder is connected to a water inlet pipe, and the right side of the storage cylinder is connected to a drain pipe. Both the water inlet pipe and the drain pipe are equipped with one-way valves. The storage cylinder is used to store clean water.

[0014] Preferably, a follower mechanism is rotatably connected to the rear side of the inner wall of the regulating pool. The follower mechanism includes a rotating shaft rotatably connected to the rear side of the inner wall of the regulating pool. A follower gear is fixed on the surface of the rotating shaft. A cleaning tube is rotatably connected to the rear side of the inner wall of the regulating pool and at the bottom of the rotating shaft. Synchronous pulleys are fixed on the surfaces of the rotating shaft and the cleaning tube. A synchronous belt is sleeved on the surfaces of the two synchronous pulleys. Multiple nozzles are connected to the surface of the cleaning tube. A follower toothed plate is fixed on the bottom of the drive plate.

[0015] Preferably, the regulating tank is rotatably connected to a stirring mechanism inside. The stirring mechanism includes a stirring shaft rotatably connected inside the regulating tank. Three sets of stirring paddles are fixed on the circumferential side of the stirring shaft. A support base is fixed on the right side of the regulating tank. A stirring motor for driving the stirring shaft to rotate is provided on the top of the support base.

[0016] Preferably, the left side of the regulating tank is connected to two inlet pipes, the bottom of the regulating tank is connected to a drain pipe, and a support frame is fixed to the periphery of the regulating tank.

[0017] A low-temperature roasting process for lithium extraction from lepidolite includes the following steps:

[0018] Step S1: Preparation of composite additive: The composite additive is composed of sulfate, chloride, oxidant and pore-forming agent in a certain mass percentage, and the mass percentage of each component is as follows: sulfate: 40%~70%, chloride: 15%~40%, oxidant: 5%~15%, pore-forming agent: 3%~10%;

[0019] Step S2, Raw material preparation: Crush and grind the lithium mica concentrate to a particle size of less than 150μm;

[0020] Step S3, Mixing Ingredients: The finely ground lithium mica powder and the composite additive are mixed evenly at a certain mass ratio:

[0021] Step S4, Low-temperature roasting: Place the mixed materials in a roasting device and roast at a temperature of 500~650℃ for 30~90 minutes;

[0022] Step S5, Calcination of Calcinated Material: The calcined material is quenched in water or cooled directly.

[0023] Step S6, Leaching and Separation: The cooled roasted clinker is leached with water or dilute acid, filtered to obtain a lithium-containing solution and leaching residue, and the leaching residue is washed multiple times with clean water.

[0024] Step S7, Wastewater Treatment: Discharge the washing water into the equalization tank, add lime slurry for preliminary neutralization and sedimentation, then discharge the water into the reaction tank to add calcium chloride, and finally add flocculant for flocculation. After flocculation, solid and liquid are separated, and after passing the test, the wastewater is discharged.

[0025] Compared with related technologies, the wastewater treatment equipment and process for lithium extraction from lithium mica by low-temperature roasting provided by this invention have the following beneficial effects:

[0026] The reciprocating frame moves the scraper to the right, pushing the foam generated during the treatment of fluoride-containing wastewater into the collection tank for discharge. This prevents solid particles, such as calcium fluoride, from being carried away by the foam and floating, thus reducing the sedimentation efficiency of the wastewater and improving the treatment effect. As the reciprocating frame moves to the right, it also moves the drive plate to the right. Through the cooperation of the rotating wheel and the moving support, the sampling cup is used to sample the foam, accurately capturing the core components such as calcium fluoride particles and surfactants carried in the foam. By testing the foam, the lime slurry addition rhythm can be optimized and the amount of calcium fluoride seed crystals added can be increased, avoiding the cost waste and secondary pollution of water caused by blindly adding reagents. By continuously moving the sampling cup to the right, the sampling cup is switched from the testing state to the cleaning state, which can avoid cross-contamination during the next sampling. Attached Figure Description

[0027] 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.

[0028] Figure 1 The optimal structural schematic diagram provided for this invention;

[0029] Figure 2 for Figure 1 The diagram shows the structure of the regulating tank in the right view.

[0030] Figure 3 for Figure 1 The diagram shows a structural schematic of the cross-sectional view of the regulating tank.

[0031] Figure 4 This is a schematic diagram of the reciprocating scraping mechanism provided by the present invention;

[0032] Figure 5 for Figure 4 The diagram shows the structure of the reciprocating frame;

[0033] Figure 6 A schematic diagram of the drive mechanism and buffer mechanism provided by the present invention;

[0034] Figure 7 The schematic diagram shows the state in which the drive plate provided by the present invention moves to the right, drives the moving bracket to move upward through the rotating wheel, and causes the sampling cup to rotate 90 degrees clockwise.

[0035] Figure 8 for Figure 7 The diagram shows the state in which the drive plate continues to move to the right, causing the sampling cup to rotate continuously counterclockwise.

[0036] Figure 9 for Figure 8 The diagram shows the state where the drive plate continues to move to the right and the sampling cup stops rotating.

[0037] Figure 10 This is a schematic diagram of the cleaning mechanism structure provided by the present invention;

[0038] Figure 11 for Figure 10 The diagram shows a cross-sectional view of the storage cylinder.

[0039] Figure 12 A schematic diagram showing the state in which the drive plate provided by the present invention moves to the right, causing the reciprocating frame to move upward via the contact wheel;

[0040] Figure 13 This is a schematic diagram of the servo mechanism provided by the present invention;

[0041] Figure 14 A schematic diagram showing the state in which the drive plate of the present invention drives the follower toothed plate to move to the right, causing the cleaning tube to rotate clockwise.

[0042] Figure 15 This is a schematic diagram of the stirring mechanism provided by the present invention;

[0043] Figure 16 This is a schematic diagram of the process flow provided by the present invention.

[0044] Explanation of icon numbers:

[0045] 1. Equalization tank;

[0046] 2. Reciprocating scraping mechanism; 21. Mounting frame; 22. Rotating rod; 23. Pulley; 24. Belt; 25. Guide rail; 26. Roller; 27. Reciprocating frame; 28. Drive motor; 29. ​​Scraper;

[0047] 3. Sampling mechanism; 31. Guide seat; 32. Slider; 33. Moving bracket; 34. Rotating shaft; 35. Sampling cup; 36. Rotating gear; 37. Rotating gear plate; 38. Rotating wheel; 39. Drive plate;

[0048] 4. Buffer mechanism; 41. Mounting bracket; 42. Sliding rod; 43. Buffer spring;

[0049] 5. Collection tank; 6. Discharge pipe; 7. Protective frame; 8. Feed pipe;

[0050] 9. Cleaning mechanism; 91. Storage cylinder; 92. Moving frame; 93. Piston; 94. Return spring; 95. Contact wheel;

[0051] 10. Follower mechanism; 101. Rotating shaft; 102. Follower gear; 103. Cleaning tube; 104. Synchronous pulley; 105. Synchronous belt; 106. Nozzle; 107. Follower gear plate;

[0052] 11. Stirring mechanism; 111. Stirring shaft; 112. Stirring paddle; 113. Support base; 114. Stirring motor;

[0053] 12. Inlet pipe; 13. Outlet pipe; 14. Support frame. 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 wastewater treatment device for lithium extraction from lithium mica by low-temperature roasting.

[0056] First embodiment:

[0057] Please see Figures 1 to 9 A wastewater treatment device for lithium extraction by low-temperature roasting of lepidolite includes an equalization tank 1, a reciprocating scraping mechanism 2, a sampling mechanism 3, and a buffer mechanism 4.

[0058] The reciprocating scraping mechanism 2 includes two mounting frames 21. The inner sides of the two mounting frames 21 are longitudinally rotatably connected to rotating rods 22. The peripheral sides of the two rotating rods 22 are fixedly provided with pulleys 23. The surfaces of the two pulleys 23 are fitted with belts 24. The front and rear sides of the inner wall of the regulating pool 1 are fixedly provided with guide rails 25. The interior of the two guide rails 25 is provided with rollers 26. The opposite sides of the two rollers 26 are rotatably connected to a reciprocating frame 27. The top of the belt 24 is fixedly connected to the reciprocating frame 27. The front of the left mounting frame 21 is provided with a drive motor 28 for driving the rotating rods 22 to rotate. The left side of the reciprocating frame 27 is fixedly provided with a scraper 29 by bolts.

[0059] The sampling mechanism 3 includes a guide seat 31 fixed to the rear side of the inner wall of the regulating pool 1. A slider 32 is slidably connected to the surface of the guide seat 31. A movable bracket 33 is fixed to the front side of the slider 32. A rotating shaft 34 is rotatably connected inside the movable bracket 33. A sampling cup 35 is fixed to the front end of the rotating shaft 34. A rotating gear 36 is fixed to the rear end of the rotating shaft 34. A rotating toothed plate 37 is fixed to the rear side of the inner wall of the regulating pool 1. The rotating gear 36 meshes with the rotating toothed plate 37. A rotating wheel 38 is rotatably connected to the front side of the movable bracket 33. A drive plate 39 is fixed to the inner side of the reciprocating frame 27.

[0060] The buffer mechanism 4 includes a mounting bracket 41 fixed to the rear side of the top of the regulating pool 1. A sliding rod 42 is vertically slidably connected inside the mounting bracket 41. The bottom end of the sliding rod 42 is fixedly connected to the top of the movable bracket 33. A buffer spring 43 is sleeved on the surface of the sliding rod 42 and at the bottom of the mounting bracket 41.

[0061] A collection trough 5 is fixedly provided on the right side of the inner wall of the regulating pool 1. Two discharge pipes 6 are connected to the right side of the regulating pool 1. Two protective frames 7 are fixedly provided on the top of the regulating pool 1. Two feed pipes 8 are provided on the inner side of the front protective frame 7. Distance sensors are fixedly provided on both sides of the inner wall of the regulating pool 1.

[0062] The inner side of the drive plate 39 is provided with a drive groove, which is composed of two straight grooves and one inclined groove, and is used in conjunction with the rotating wheel 38. The rotating tooth plate 37 is composed of two tooth groups, which are on the same vertical line and are separated from each other.

[0063] Preferably, the feed pipe 8 is used to add lime slurry into the equalization tank 1;

[0064] Please combine Figures 3 to 5 Start the drive motor 28. The drive motor 28 rotates, which in turn drives the left rotating rod 22 to rotate. The rotation of the left rotating rod 22 drives the pulley 23 to rotate, which in turn drives the belt 24 to rotate. The rotation of the belt 24 drives the reciprocating frame 27 to move to the right, causing the roller 26 to rotate inside the guide rail 25. The movement of the reciprocating frame 27 to the right drives the scraper 29 to move to the right, thereby scraping the foam on the water surface into the collection tank 5 and discharging it through the discharge pipe 6.

[0065] Please combine Figures 6 to 9When the reciprocating frame 27 moves to the right and scrapes the foam into the collection tank 5 through the scraper 29, it will simultaneously drive the drive plate 39 to move to the right. When the drive plate 39 moves to the right, causing the rotating wheel 38 to enter the inner side of the drive plate 39 and continue to move to the right, under the action of the drive tank, the drive plate 39 will drive the moving bracket 33 to move upward through the rotating wheel 38. The moving bracket 33 moves upward, which in turn drives the rotating shaft 34, the sampling cup 35 and the rotating gear 36 to move upward. The rotating gear 36 moves upward, and under the action of the rotating toothed plate 37, it will drive the sampling cup 35 to rotate 90 degrees clockwise through the rotating shaft 34, thereby completing the sampling of the foam.

[0066] Preferably, the sampling cup 35 has its opening facing to the left. When the scraper 29 moves to the right and scrapes the foam into the collection tank 5, the foam will enter the sampling cup 35.

[0067] Preferably, the distance sensor is used to detect the working position of the scraper 29, thereby knowing the working status of the sampling cup 35 and the scraper 29;

[0068] Furthermore, as the drive plate 39 continues to move to the right, the rotating gear 36 will disengage from the rotating toothed plate 37, keeping the sampling cup vertical. With the cooperation of the rotating wheel 38 and the moving bracket 33, the sampling cup 35 will remain vertical and move upward, thereby switching the sampling cup 35 to the detection state.

[0069] Furthermore, as the drive plate 39 continues to move to the right, the rotating gear 36 re-engages with the rotating toothed plate 37. Under the action of the rotating wheel 38, the moving bracket 33 moves upward, driving the rotating gear 36 to move upward, causing the rotating shaft 34 to drive the sampling cup 35 to rotate clockwise, thereby switching the sampling cup 35 to the cleaning state and pouring the foam in the sampling cup 35 into the collection tank 5.

[0070] Furthermore, when the drive plate 39 continues to move to the right and the wheel 38 is located at the top horizontal groove of the drive groove inside the drive plate 39, the moving bracket 33 and the sampling cup 35 will not move, the sampling cup 35 will remain in the cleaning state, and the drive plate 39 will remain in the working state of moving to the right.

[0071] In this embodiment, the reciprocating frame 27 drives the scraper 29 to move to the right, pushing the foam generated during the treatment of fluoride-containing wastewater into the collection tank 5 for discharge. This prevents solid particles such as calcium fluoride from being carried by the foam, causing them to float and reducing the sedimentation efficiency of the wastewater, thus improving the treatment effect. When the reciprocating frame 27 moves to the right, it also drives the drive plate 39 to move to the right. Through the cooperation of the rotating wheel 38 and the moving support 33, the sampling cup 35 is used to sample the foam, accurately capturing the core components such as calcium fluoride particles and surfactants carried in the foam. By detecting the foam, the lime milk addition rhythm can be optimized and the amount of calcium fluoride seed crystals added can be increased, avoiding the cost waste and secondary water pollution caused by blindly adding reagents. By continuously driving the sampling cup 35 to the right by the reciprocating frame 27, the sampling cup 35 is switched from the detection state to the cleaning state, which can avoid cross-contamination during the next sampling.

[0072] Second embodiment:

[0073] Please see Figures 10 to 12 A cleaning mechanism 9 is fixedly provided on the inner side of the mounting bracket 41. The cleaning mechanism 9 includes a storage cylinder 91 fixed inside the mounting bracket 41. A movable frame 92 is slidably connected inside the storage cylinder 91. A piston 93 is fixedly provided at the top of the movable frame 92 and inside the storage cylinder 91. A return spring 94 is sleeved on the surface of the movable frame 92 and at the bottom of the storage cylinder 91. A contact wheel 95 is rotatably connected to the inner side of the movable frame 92.

[0074] The top of the storage cylinder 91 is connected to a water inlet pipe, and the right side of the storage cylinder 91 is connected to a drain pipe. Both the water inlet pipe and the drain pipe are equipped with one-way valves. The storage cylinder 91 is used to store clean water.

[0075] Please combine Figures 10 to 12 When the sample 35 is switched to the cleaning state and the drive plate 39 continues to move to the right, the top right side of the drive plate 39 will contact the contact wheel 95. Under the action of the drive plate 39 continuing to move to the right, the contact wheel 95 pushes the moving frame 92 to move upward. The moving frame 92 moves upward, thereby driving the piston 93 to move upward, discharging clean water from the storage cylinder 91 and cleaning the sample cup 35.

[0076] Furthermore, when the drive plate 39 is reset to the left, under the elastic force of the reset spring 94, the moving frame 92 will drive the contact wheel 95 and the piston 93 to move downward, and use the piston 93 to draw in new clean water.

[0077] In this embodiment, the drive plate 39 moves to the right, switching the sampling cup 35 to the cleaning state. The drive plate 39 continues to move to the right, and with the cooperation of the contact wheel 95 and the moving frame 92, the piston 93 moves upward in the storage cylinder 91, thereby discharging clean water from the storage cylinder 91 and cleaning the sampling cup 35. Although the foam is poured out in the cleaning state, a small amount of foam residue or fine calcium fluoride particles will remain in the cup. If not cleaned in time, these residues will mix with the new foam during the next sampling, resulting in distorted sampling composition and deviation in the detection data.

[0078] Third embodiment:

[0079] Please see Figure 1 , Figure 2 , Figures 13 to 15 A follower mechanism 10 is rotatably connected to the rear side of the inner wall of the regulating pool 1. The follower mechanism 10 includes a rotating shaft 101 rotatably connected to the rear side of the inner wall of the regulating pool 1. A follower gear 102 is fixed on the surface of the rotating shaft 101. A cleaning tube 103 is rotatably connected to the rear side of the inner wall of the regulating pool 1 and located at the bottom of the rotating shaft 101. Synchronous pulleys 104 are fixed on the surfaces of both the rotating shaft 101 and the cleaning tube 103. Synchronous belts 105 are sleeved on the surfaces of the two synchronous pulleys 104. Multiple nozzles 106 are connected to the surface of the cleaning tube 103. A follower toothed plate 107 is fixed on the bottom of the drive plate 39.

[0080] The regulating tank 1 is rotatably connected to a stirring mechanism 11 inside. The stirring mechanism 11 includes a stirring shaft 111 rotatably connected inside the regulating tank 1. Three sets of stirring paddles 112 are fixed on the circumferential side of the stirring shaft 111. A support base 113 is fixed on the right side of the regulating tank 1. A stirring motor 114 for driving the stirring shaft 111 to rotate is provided on the top of the support base 113.

[0081] The left side of the regulating tank 1 is connected to two sewage inlet pipes 12, the bottom of the regulating tank 1 is connected to a sewage outlet pipe 13, and a support frame 14 is fixedly provided on the periphery of the regulating tank 1.

[0082] Please combine Figure 13 and Figure 14 When the drive plate 39 moves to the right and its top contacts the contact wheel 95, the follower toothed plate 107 will simultaneously mesh with the follower gear 102. As the drive plate 39 continues to move to the right, the follower toothed plate 107 will drive the follower gear 102 to rotate. The rotation of the follower gear 102 will drive the rotating shaft 101 and the top synchronous wheel 104 to rotate. Through the synchronous belt 105, the bottom synchronous wheel 104 and the cleaning tube 103 will rotate, thereby causing the nozzle 106 to swing and clean the sampling cup 35.

[0083] Please combine Figure 15 Start the stirring motor 114. The stirring motor 114 rotates, which in turn drives the stirring shaft 111 and the stirring paddle 112 to rotate. The rotation of the stirring paddle 112 mixes the fluoride-containing wastewater and lime slurry.

[0084] In this embodiment, when the drive plate 39 moves to the right and its top contacts the contact wheel 95, it will simultaneously drive the follower gear plate 107 to move to the right. With the cooperation of the follower gear 102, the synchronous wheel 104 and the synchronous belt 105, the cleaning tube 103 will rotate, causing the nozzle 106 to swing and clean the sampling cup 35. The swing angle can cover the inner wall and opening edge of the sampling cup 35, which can thoroughly remove the calcium fluoride fine particles and foam residue remaining in the corners of the cup.

[0085] The present invention also provides a process for lithium extraction from lepidolite by low-temperature roasting.

[0086] Please see Figure 16 A lithium extraction process using low-temperature roasting of lepidolite includes the following steps:

[0087] Step S1: Preparation of composite additive: The composite additive is composed of sulfate, chloride, oxidant and pore-forming agent in a certain mass percentage, and the mass percentage of each component is as follows: sulfate: 40%~70%, chloride: 15%~40%, oxidant: 5%~15%, pore-forming agent: 3%~10%;

[0088] Step S2, Raw material preparation: Crush and grind the lithium mica concentrate to a particle size of less than 150μm;

[0089] Step S3, Mixing Ingredients: The finely ground lithium mica powder and the composite additive are mixed evenly at a certain mass ratio:

[0090] Step S4, Low-temperature roasting: Place the mixed materials in a roasting device and roast at a temperature of 500~650℃ for 30~90 minutes;

[0091] Step S5, Calcination of Calcinated Material: The calcined material is quenched in water or cooled directly.

[0092] Step S6, Leaching and Separation: The cooled roasted clinker is leached with water or dilute acid, filtered to obtain a lithium-containing solution and leaching residue, and the leaching residue is washed multiple times with clean water.

[0093] Step S7, Wastewater Treatment: Discharge the washing water into equalization tank 1, add lime slurry for preliminary neutralization and sedimentation, then discharge the water into reaction tank to add calcium chloride, and finally add flocculant for flocculation. After flocculation, solid and liquid are separated, and after passing the test, the wastewater is discharged.

[0094] Preferably, in step S1, the sulfate is one or a mixture of two of sodium sulfate and potassium sulfate, which reacts with lithium in lepidolite to generate soluble lithium sulfate, while providing a sulfate environment.

[0095] Preferably, in step S1, the chloride is one or a mixture of two of calcium chloride and sodium chloride. The addition of chloride (especially CaCl2) can react with fluoride ions in the lepidolite structure to generate stable CaF2, effectively fixing fluorine elements, reducing the escape of HF gas from the source, reducing environmental pollution and equipment corrosion. At the same time, the introduction of chloride ions can destroy the aluminosilicate framework and promote the release of lithium.

[0096] Preferably, in step S1, the oxidant is one or a mixture of two of sodium nitrate and calcium nitrate. When heated and decomposed, the oxidant can provide nascent oxygen and release heat, which helps to activate the reaction at a lower temperature and promote the disintegration of the lepidolite structure and the conversion of lithium.

[0097] Preferably, in step S1, the pore-forming agent is one or more of calcium carbonate, sodium carbonate, and Ca(OH)2. When the pore-forming agent is heated and decomposed, it will generate gas, which will cause the roasted material to form a porous structure, increase the reaction contact area, and benefit the subsequent leaching process and improve the leaching efficiency.

[0098] In this embodiment, through the synergistic effect among the components, the high temperature of 800~950℃ in the traditional process is significantly reduced to 500~650℃, resulting in significant energy saving and consumption reduction. The lithium extraction rate is high, and the composite additive can efficiently destroy the crystal structure of lepidolite, converting lithium into easily soluble lithium sulfate. The lithium conversion rate and leaching rate are high and stable. The chloride in the additive can effectively fix fluorine, greatly reducing the emission of harmful gases such as HF. The use of oxidant reduces the generation of sulfur oxides. The low temperature avoids the large-scale volatilization of volatile valuable elements such as potassium, sodium, rubidium, and cesium, allowing them to accumulate in the leaching residue or leachate, creating favorable conditions for subsequent comprehensive recovery. The pore-forming agent makes the roasted product loose and porous, easy to leach, reducing energy consumption and cost. Through multi-stage wastewater treatment, fluoride removal is carried out layer by layer to ensure that the wastewater meets the standards. At the same time, the treatment process complements the roasting and fluoride fixation, achieving dual zeroing of fluoride pollution at both the source and end.

[0099] Please refer to the reference again. Figures 1 to 15 The working principle of the wastewater treatment equipment for lithium extraction from low-temperature roasting of lepidolite provided by this invention is as follows:

[0100] Step S1: Discharge the washing water into the equalization tank 1, add lime milk for preliminary neutralization and sedimentation, start the stirring motor 114, the stirring motor 114 rotates and drives the stirring shaft 111 and stirring paddle 112 to rotate, and mix the fluoride-containing wastewater and lime milk by the rotation of the stirring paddle 112.

[0101] Then start the drive motor 28. The drive motor 28 rotates and drives the left rotating rod 22 to rotate. The left rotating rod 22 rotates and drives the pulley 23 to rotate, which causes the belt 24 to rotate. The belt 24 rotates and drives the reciprocating frame 27 to move to the right, causing the roller 26 to rotate inside the guide rail 25. The reciprocating frame 27 moves to the right and drives the scraper 29 to move to the right, thereby scraping the foam generated on the water surface into the collection tank 5 and discharging it through the discharge pipe 6.

[0102] In step S2, when the reciprocating frame 27 moves to the right and scrapes the foam into the collection tank 5 through the scraper 29, it will simultaneously drive the drive plate 39 to move to the right. When the drive plate 39 moves to the right, causing the rotating wheel 38 to enter the inner side of the drive plate 39 and continue to move to the right, under the action of the drive tank, the drive plate 39 will drive the moving bracket 33 to move upward through the rotating wheel 38. The moving bracket 33 moves upward, which in turn drives the rotating shaft 34, the sampling cup 35 and the rotating gear 36 to move upward. The rotating gear 36 moves upward, and under the action of the rotating toothed plate 37, it will drive the sampling cup 35 to rotate 90 degrees clockwise through the rotating shaft 34, thereby completing the sampling of the foam.

[0103] In step S3, combined with step S2, when the drive plate 39 continues to move to the right, the rotating gear 36 will disengage from the rotating toothed plate 37, keeping the sampling cup vertical. With the cooperation of the rotating wheel 38 and the moving bracket 33, the sampling cup 35 will remain vertical and move upward, thereby switching the sampling cup 35 to the detection state.

[0104] In step S4, combined with step S3, when the drive plate 39 continues to move to the right, the rotating gear 36 re-engages with the rotating toothed plate 37. Under the action of the rotating wheel 38, the moving bracket 33 moves upward, driving the rotating gear 36 to move upward, so that the rotating shaft 34 drives the sampling cup 35 to rotate clockwise, thereby switching the sampling cup 35 to the cleaning state and pouring the foam in the sampling cup 35 into the collection tank 5.

[0105] In step S5, combined with step S4, when sample 35 is switched to the cleaning state and the drive plate 39 continues to move to the right, the top right side of the drive plate 39 will contact the contact wheel 95. Under the action of the drive plate 39 continuing to move to the right, the contact wheel 95 pushes the moving frame 92 upward. The upward movement of the moving frame 92 drives the piston 93 upward, discharging clean water from the storage cylinder 91 and cleaning the sample cup 35.

[0106] In step S6, combined with step S5, the drive plate 39 moves to the right. When the top contacts the contact wheel 95, the follower toothed plate 107 simultaneously meshes with the follower gear 102. As the drive plate 39 continues to move to the right, the follower toothed plate 107 drives the follower gear 102 to rotate. The rotation of the follower gear 102 drives the rotating shaft 101 and the top synchronous wheel 104 to rotate. Through the synchronous belt 105, the bottom synchronous wheel 104 and the cleaning tube 103 are driven to rotate, thereby causing the nozzle 106 to swing and clean the sampling cup 35.

[0107] 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 wastewater treatment device for lithium extraction from lithium mica by low-temperature roasting, characterized in that, It includes a regulating tank, a reciprocating scraping mechanism, a sampling mechanism, and a buffer mechanism; The reciprocating scraping mechanism includes two mounting frames. A rotating rod is longitudinally rotatably connected to the inner side of each mounting frame. A pulley is fixed to the circumferential side of each rotating rod. A belt is fitted onto the surface of each pulley. Guide rails are fixed to the front and rear sides of the inner wall of the regulating tank. Rollers are installed inside each guide rail. A reciprocating frame is rotatably connected to the opposite side of each roller. The top of the belt is fixedly connected to the reciprocating frame. A drive motor for rotating the rotating rod is installed on the front of the left mounting frame. A scraper is fixed to the left side of the reciprocating frame by bolts. The sampling mechanism includes a guide seat fixed to the rear side of the inner wall of the regulating tank. A slider is slidably connected to the surface of the guide seat. A movable bracket is fixed to the front of the slider. A rotating shaft is rotatably connected inside the movable bracket. A sampling cup is fixed to the front end of the rotating shaft. A rotating gear is fixed to the rear end of the rotating shaft. A rotating toothed plate is fixed to the rear side of the inner wall of the regulating tank. The rotating gear meshes with the rotating toothed plate. A rotating wheel is rotatably connected to the front of the movable bracket. A drive plate is fixed to the inner side of the reciprocating frame. The buffer mechanism includes a mounting bracket fixed to the rear side of the top of the regulating pool. A sliding rod is vertically slidably connected inside the mounting bracket. The bottom end of the sliding rod is fixedly connected to the top of the movable bracket. A buffer spring is sleeved on the surface of the sliding rod and at the bottom of the mounting bracket.

2. The wastewater treatment equipment for lithium extraction from lithium mica at low temperature according to claim 1, characterized in that, A collection trough is fixedly provided on the right side of the inner wall of the regulating pool. Two discharge pipes are connected to the right side of the regulating pool. Two protective frames are fixedly provided on the top of the regulating pool. Two feed pipes are provided on the inner side of the front protective frame. Distance sensors are fixedly provided on both sides of the inner wall of the regulating pool.

3. The wastewater treatment equipment for lithium extraction from lithium mica at low temperature according to claim 1, characterized in that, The inner side of the drive plate is provided with a drive groove, which consists of two straight grooves and one inclined groove, and is used in conjunction with the rotating wheel. The rotating toothed plate is composed of two tooth groups, which are on the same vertical line and are separated from each other.

4. The wastewater treatment equipment for lithium extraction from lithium mica at low temperature according to claim 1, characterized in that, A cleaning mechanism is fixedly provided on the inner side of the mounting bracket. The cleaning mechanism includes a storage cylinder fixed inside the mounting bracket. A movable frame is slidably connected inside the storage cylinder. A piston is fixedly provided at the top of the movable frame and inside the storage cylinder. A return spring is sleeved on the surface of the movable frame and at the bottom of the storage cylinder. A contact wheel is rotatably connected to the inner side of the movable frame.

5. The wastewater treatment equipment for lithium extraction from lithium mica by low-temperature roasting according to claim 4, characterized in that, The top of the storage cylinder is connected to a water inlet pipe, and the right side of the storage cylinder is connected to a drain pipe. Both the water inlet pipe and the drain pipe are equipped with one-way valves. The storage cylinder is used to store clean water.

6. The wastewater treatment equipment for lithium extraction from lithium mica by low-temperature roasting according to claim 1, characterized in that, A follower mechanism is rotatably connected to the rear side of the inner wall of the regulating pool. The follower mechanism includes a rotating shaft rotatably connected to the rear side of the inner wall of the regulating pool. A follower gear is fixed on the surface of the rotating shaft. A cleaning tube is rotatably connected to the rear side of the inner wall of the regulating pool and at the bottom of the rotating shaft. Synchronous pulleys are fixed on the surfaces of the rotating shaft and the cleaning tube. A synchronous belt is sleeved on the surfaces of the two synchronous pulleys. Multiple nozzles are connected to the surface of the cleaning tube. A follower toothed plate is fixed on the bottom of the drive plate.

7. The wastewater treatment equipment for lithium extraction from lithium mica at low temperature according to claim 1, characterized in that, The regulating tank is rotatably connected to a stirring mechanism inside. The stirring mechanism includes a stirring shaft rotatably connected inside the regulating tank. Three sets of stirring blades are fixed on the circumferential side of the stirring shaft. A support base is fixed on the right side of the regulating tank. A stirring motor that drives the stirring shaft to rotate is installed on the top of the support base.

8. The wastewater treatment equipment for lithium extraction from lithium mica by low-temperature roasting according to claim 1, characterized in that, The left side of the regulating tank is connected to two inlet pipes, the bottom of the regulating tank is connected to a drain pipe, and a support frame is fixed to the periphery of the regulating tank.

9. A low-temperature roasting process for lithium extraction from lepidolite, characterized in that, The lithium extraction process by low-temperature roasting of lepidolite includes the wastewater treatment equipment for lithium extraction as described in any one of claims 1-8 and the following steps: Step S1: Preparation of composite additive: The composite additive is composed of sulfate, chloride, oxidant and pore-forming agent in a certain mass percentage, and the mass percentage of each component is as follows: sulfate: 40%~70%, chloride: 15%~40%, oxidant: 5%~15%, pore-forming agent: 3%~10%; Step S2, Raw material preparation: Crush and grind the lithium mica concentrate to a particle size of less than 150μm; Step S3, Mixing Ingredients: The finely ground lithium mica powder and the composite additive are mixed evenly at a certain mass ratio: Step S4, Low-temperature roasting: Place the mixed materials in a roasting device and roast at a temperature of 500~650℃ for 30~90 minutes; Step S5, Calcination of Calcinated Material: The calcined material is quenched in water or cooled directly. Step S6, Leaching and Separation: The cooled roasted clinker is leached with water or dilute acid, filtered to obtain a lithium-containing solution and leaching residue, and the leaching residue is washed multiple times with clean water. Step S7, Wastewater Treatment: Discharge the washing water into the equalization tank, add lime slurry for preliminary neutralization and sedimentation, then discharge the water into the reaction tank to add calcium chloride, and finally add flocculant for flocculation. After flocculation, solid and liquid are separated, and after passing the test, the wastewater is discharged.

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