Atmospheric pollution treatment device and method for co-producing lithium and lithium phosphate and cryolite

Abstract

This invention provides an air pollution control device and a method for lithium extraction and co-production of cryolite and lithium phosphate. Relating to the field of air pollution control, the air pollution control device includes a tower placed on the ground. The air pollution control device and method provided by this invention utilize a packing disc to support spherical packing material, allowing sodium hydroxide solution to form a uniform liquid film on the surface of the spherical packing material. By using a sprinkler to slow the flow rate and ensure uniform distribution, the sodium hydroxide solution covers the packing material in the form of fine droplets rather than large streams of water, further increasing the effective contact area with the roasting gas, thereby significantly improving adsorption and separation efficiency. The waterproof plate prevents sodium hydroxide solution from entering the inlet pipe while also slowing the rise and diffusion of the roasting gas. The lower and more uniform flow rate means a longer residence time of the gas in the packing layer, improving mass transfer efficiency and ensuring complete treatment.

Description

Technical Field

[0001] This invention relates to the field of air pollution control, and in particular to an air pollution control device and a method for lithium extraction and co-production of cryolite and lithium phosphate. Background Technology

[0002] To extract lithium resources by roasting lepidolite concentrate, the powdered lepidolite concentrate needs to be mixed and ground with sodium bisulfate and then roasted in a muffle furnace. Under high temperature roasting, complex gases are generated, including acidic gases such as sulfur dioxide and inorganic salt dust. Direct emission of these gases would cause air pollution. The roasting gases are treated by introducing them into an air pollution control device to ensure that they are discharged in compliance with standards.

[0003] Existing air pollution control devices introduce gas into the interior of a spray tower from bottom to top through a gas supply pipe. Simultaneously, a spraying liquid is sprayed from top to bottom to adsorb and separate acidic gases using an alkaline solution. The treated gas is then discharged from the top of the tower in compliance with emission standards.

[0004] However, existing air pollution control devices use water pumps to lift the spray liquid to the top of the spray tower and then spray it downwards when treating roasted gases. The excessively fast flow rate of the spray liquid and the short contact time with the roasted gases result in incomplete treatment and excessive emissions of roasted gases.

[0005] Therefore, it is necessary to provide an air pollution control device and a method for lithium extraction and co-production of cryolite and lithium phosphate to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides an air pollution control device and a method for lithium extraction and co-production of cryolite and lithium phosphate, which solves the problem of incomplete treatment and excessive emissions of roasting gas due to insufficient contact time between spray liquid and roasting gas.

[0007] To solve the above-mentioned technical problems, the present invention provides an air pollution control device, comprising: a tower body placed on the ground;

[0008] An air inlet pipe, the outlet end of which passes through one side of the tower body and extends into the interior;

[0009] An exhaust pipe, which connects to the top of the tower body;

[0010] The spraying mechanism includes a return pipe connected to the bottom of the tower body. One end of the return pipe is connected to a spray box located on the ground. A lift pump is fixedly installed on the top of the spray box. The input end of the lift pump is connected to the interior of the spray box via a suction pipe. The output end of the lift pump is connected to a lift pipe. The end of the lift pipe penetrates the outer wall of the tower body and extends into the interior. A sprinkler is connected to the end of the lift pipe. Several spray holes are provided at the bottom of the sprinkler.

[0011] A packing disc is fixedly installed on the inner wall of the tower body, and spherical packing is placed on top of the packing disc.

[0012] Preferably, a waterproof plate is fixedly installed at one end of the air inlet pipe inside the tower body via a bracket, and the waterproof plate is adapted to the air inlet pipe.

[0013] Preferably, the end of the exhaust pipe is connected to a purification mechanism via a second connecting pipe. The purification mechanism includes a purification tank. One side of the purification tank is connected to the end of the exhaust pipe via the second connecting pipe, and the other side of the purification tank is connected to an exhaust pipe. The purification tank is placed on the ground, and a demisting plate and an activated carbon box are fixedly installed inside the purification tank.

[0014] Preferably, the air intake end of the air intake pipe is connected to a pretreatment tank via a connecting pipe. The pretreatment tank is located on the ground, and two guide rails are symmetrically fixedly installed on the top and bottom of the inner wall of the pretreatment tank.

[0015] Preferably, the pretreatment tank is connected to two sides by a gas supply mechanism, the gas supply mechanism includes an air pipe, the air pipe is connected to both sides of the pretreatment tank, the top of the air pipe is connected to a solenoid valve through the gas supply pipe, and the bottom of the solenoid valve is connected to a gas storage tank through a connecting pipe, the gas storage tank being installed on the ground.

[0016] Preferably, a filter plate mechanism is slidably installed inside the four guide rails. The filter plate mechanism includes a filter plate, which is slidably installed inside the four guide rails. A connecting plate is fixedly installed on both sides of the filter plate, and a driving block is fixedly installed on the bottom of each of the two connecting plates.

[0017] Preferably, two pendulum mechanisms are symmetrically and rotatably installed on both sides of the inner wall of the pretreatment tank. Each pendulum mechanism includes a first rotating shaft and a second rotating shaft. The first rotating shaft and the second rotating shaft are respectively rotatably installed on both sides of the inner wall of the pretreatment tank. A first pendulum is fixedly installed on the surface of the first rotating shaft through a connecting rod, and a first convex shaft is fixedly installed on one end of the first rotating shaft. A second pendulum is fixedly installed on the surface of the second rotating shaft through a connecting rod, and a second convex shaft is fixedly installed on one end of the second rotating shaft. The two driving blocks are respectively adapted and installed to the two first convex shafts and the two second convex shafts.

[0018] Preferably, a take-up coil is symmetrically fixedly installed at the bottom of the inner wall of the pretreatment tank, and the outlet ends of the two take-up coils are fixedly connected to one side of the filter plate. A stop block is symmetrically fixedly installed at the top of the two guide rails located at the bottom of the inner wall of the pretreatment tank, and the four stop blocks are adapted to the filter plate.

[0019] Preferably, air baffles are fixedly installed on both sides of the filter plate, and the two air baffles are adapted to the pretreatment tank. A switch is fixedly installed on one side of the inner wall of the pretreatment tank, and the air baffles are adapted to the switch.

[0020] A method for lithium extraction and co-production of cryolite and lithium phosphate includes the following steps:

[0021] S1: Take lumpy lepidolite ore, crush it with a jaw crusher, weigh a certain amount of crushed raw material and transfer it to a ball mill jar, add deionized water, perform wet grinding to suppress dust, set the ball mill to a certain speed for grinding, and after grinding, pass the slurry through a 200-mesh standard sieve. The coarse particles on the sieve are returned to the ball mill jar for secondary grinding, and the fine slurry under the sieve is filtered by a vacuum filtration device to obtain a filter cake. The filter cake is placed in an oven to dry for a period of time to obtain lepidolite concentrate. The lepidolite concentrate has a water content of ≤5%. Grind it into powder with an agate mortar and pestle, and store it in a sealed container.

[0022] S2: Weigh a certain amount of powdered lepidolite concentrate and mix it with sodium bisulfite. Mix thoroughly and grind with an agate mortar to ensure uniform contact. Transfer the mixture to a corundum crucible, place it in a muffle furnace, set the program, heat to 500℃ at a heating rate of 5℃ / min, hold for a period of time, and allow to cool naturally to room temperature. Grind the calcined product through a 100-mesh sieve using an agate mortar to obtain the calcined material. Seal and store the material. The gas generated during calcination is treated in an air pollution control device to meet emission standards.

[0023] S3: Weigh a certain amount of calcined material, transfer it to a beaker, add deionized water and mix it evenly according to a certain liquid-solid ratio. Heat the water bath to 95°C, set the magnetic stirrer to a certain speed and stir for a period of time. After the leaching is completed, immediately filter the solution and collect the leachate. Wash the filter residue twice with deionized water preheated to 95°C, stirring for 5 minutes each time and then filter it. Combine the washing liquids into a volumetric flask.

[0024] S4: Take a certain amount of leachate and concentrate it using a rotary evaporator. ,reduce Dosage: Transfer the concentrated solution to a beaker, turn on the magnetic stirrer, and use 1 mol / L The solution was titrated, with the pH recorded after each addition of a certain amount of solution, until pH = 9.00 ± 0.05. After titration, the solution was stirred in a 30°C constant temperature water bath for a period of time to obtain a mixture. The mixture was transferred to a centrifuge tube and centrifuged at a certain speed to obtain the supernatant. The supernatant was collected in three batches. The precipitated impurities were washed three times with deionized water and dried to obtain cryolite as the main phase. The sediment;

[0025] S5: Take a certain amount of the supernatant, transfer it to a beaker, heat it in a water bath to 90℃, stir magnetically at 200-400 rpm, and slowly add 1 mol / L... Add the solution dropwise at a rate of 1 mL per minute to avoid localized overconcentration. After the addition is complete, continue stirring for a period of time. Filter the reaction solution using a glass frit funnel. Wash the precipitate three times with deionized water preheated to 95°C, filtering for 10 minutes each time to ensure thorough washing. The precipitate formed after filtration was transferred to a ceramic boat and dried in an oven at 105°C to obtain lithium phosphate. product.

[0026] Compared with related technologies, the air pollution control device provided by the present invention has the following beneficial effects:

[0027] This invention provides an air pollution control device. By setting up a packing disc to support spherical packing, a sodium hydroxide solution forms a uniform liquid film on the surface of the spherical packing. By setting up a sprinkler to slow down the flow rate and ensure uniform distribution, the sodium hydroxide solution can cover the packing in the form of fine droplets rather than large streams of water, further increasing the effective contact area with the roasted gas, thereby significantly improving the adsorption and separation efficiency. By setting up a waterproof plate, the sodium hydroxide solution is prevented from entering the air inlet pipe, while also slowing down the rising speed of the roasted gas and diffusing the roasted gas. The lower and more uniform flow rate means that the residence time of the gas in the packing layer is extended, improving the mass transfer efficiency and ensuring complete treatment. Attached Figure Description

[0028] Figure 1 A schematic diagram of a preferred embodiment of an air pollution control device provided by the present invention;

[0029] Figure 2 Another structural schematic diagram of a preferred embodiment of an air pollution control device;

[0030] Figure 3 for Figure 2 The diagram shows the structure of the spraying mechanism.

[0031] Figure 4 for Figure 3 Another schematic diagram of the spray mechanism shown;

[0032] Figure 5 This is a schematic diagram of the structure of a second embodiment of an air pollution control device;

[0033] Figure 6 for Figure 5 The diagram shows the installation of the gas transmission mechanism;

[0034] Figure 7 for Figure 6 The diagram shows the installation of the guide rail;

[0035] Figure 8 for Figure 5 The diagram shown is a structural schematic of the purification mechanism.

[0036] Figure 9 for Figure 6 The diagram shows the structure of the gas transmission mechanism.

[0037] Figure 10 for Figure 6 The diagram shows the installation of the filter plate mechanism and the pendulum mechanism.

[0038] Figure 11 for Figure 10 The diagram shows the structure of the filter plate mechanism.

[0039] Figure 12 for Figure 10 The diagram shows the structure of the pendulum mechanism.

[0040] The diagram labels are as follows: 1. Tower body; 2. Air inlet pipe; 3. Exhaust pipe; 4. Spraying mechanism; 401. Return pipe; 402. Spray box; 403. Booster pump; 404. Booster pipe; 405. Sprinkler; 406. Sprinkler hole; 5. Packing disc; 6. Gas delivery mechanism; 601. Air pipe; 602. Gas delivery pipe; 603. Solenoid valve; 604. Gas storage tank; 7. Filter plate mechanism; 701. Filter plate; 702. Connecting plate; 703. Drive block; 8. Pendulum mechanism. 801. First rotating shaft; 802. First pendulum; 803. First convex shaft; 804. Second rotating shaft; 805. Second pendulum; 806. Second convex shaft; 9. Purification mechanism; 901. Purification tank; 902. Air outlet pipe; 903. Demisting plate; 904. Activated carbon box; 10. Waterproof plate; 11. Pretreatment tank; 12. Guide rail; 13. Cable retractor; 14. Stop block; 15. Connecting air pipe one; 16. Air baffle; 17. Switch; 18. Connecting air pipe two. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] An air pollution control device

[0043] First Embodiment

[0044] Please refer to the following: Figure 1 , Figure 2 , Figure 3 Figure 4 An air pollution control device includes: a tower body 1 placed on the ground;

[0045] Air inlet pipe 2, the outlet end of which passes through one side of the tower body 1 and extends into the interior;

[0046] Exhaust pipe 3, which is connected to the top of the tower body 1;

[0047] The spraying mechanism 4 includes a return pipe 401, which is connected to the bottom of the tower body 1. One end of the return pipe 401 is connected to a spray box 402, which is located on the ground. A lift pump 403 is fixedly installed on the top of the spray box 402. The input end of the lift pump 403 is connected to the interior of the spray box 402 through a suction pipe. The output end of the lift pump 403 is connected to a lift pipe 404. The end of the lift pipe 404 penetrates the outer wall of the tower body 1 and extends into the interior. The end of the lift pipe 404 is connected to a sprinkler 405, and the bottom of the sprinkler 405 has several spray holes 406.

[0048] The packing disc 5 is fixedly installed on the inner wall of the tower body 1, and spherical packing is placed on the top of the packing disc 5.

[0049] A waterproof plate 10 is fixedly installed at one end of the air inlet pipe 2 inside the tower body 1 via a bracket, and the waterproof plate 10 is adapted to the air inlet pipe 2.

[0050] In actual use, the tower body 1 is a spray tower; the air pollution control device can be used for the treatment of other gases of the same type; the reagent inside the spray box 402 is a sodium hydroxide solution; the air inlet pipe 2 is a right-angle pipe; and the spherical packing is a porous ceramic material.

[0051] The working principle of the air pollution control device provided by this invention is as follows:

[0052] First, the booster pump 403 is started to input the sodium hydroxide solution inside the spray box 402 into the sprinkler 405 through the booster pipe 404. While distributing the sodium hydroxide solution, the sprinkler 405 slows down the flow rate and sprays downward through the spray hole 406. The sprayed sodium hydroxide solution contacts the spherical packing on the packing disc 5.

[0053] Then, the roasting gas is introduced into the interior of the tower body 1 through the air inlet pipe 2. The gas is diffused by the waterproof plate 10 while the rising speed of the flue gas is slowed down. The roasting gas flows into the packing disk 5 and comes into contact with the spherical packing, increasing the contact area between the sodium hydroxide solution and the roasting gas.

[0054] Finally, the roasting gas is deacidified and discharged from exhaust pipe 3.

[0055] Compared with related technologies, the air pollution control device provided by the present invention has the following beneficial effects:

[0056] By setting the packing disc 5 to support the spherical packing, a uniform liquid film of sodium hydroxide solution is formed on the surface of the spherical packing. By setting the water sprayer 405 to slow down the flow rate and distribute it evenly, it is ensured that the sodium hydroxide solution can cover the packing in the form of fine droplets rather than large streams of water, further increasing the effective contact area with the roasting gas, thereby significantly improving the adsorption and separation efficiency. By setting the waterproof plate 10, the sodium hydroxide solution is prevented from entering the gas inlet pipe 2, while also slowing down the rising speed of the roasting gas and diffusing the roasting gas. The lower and more uniform flow rate means that the residence time of the gas in the packing layer is extended, improving the mass transfer efficiency and ensuring that the treatment is completed.

[0057] Second Embodiment

[0058] Please refer to the following: Figures 5-12 Based on the air pollution control device provided in the first embodiment of this application, the second embodiment of this application proposes another air pollution control device. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0059] Specifically, the second embodiment of this application provides an air pollution control device that differs in that the end of the exhaust pipe 3 is connected to a purification mechanism 9 via a connecting pipe 2 18. The purification mechanism 9 includes a purification tank 901. One side of the purification tank 901 is connected to the end of the exhaust pipe 3 via the connecting pipe 2 18, and the other side of the purification tank 901 is connected to an exhaust pipe 902. The purification tank 901 is installed on the ground, and a demisting plate 903 and an activated carbon box 904 are fixedly installed inside the purification tank 901.

[0060] The air intake end of the air intake pipe 2 is connected to the pretreatment tank 11 through the connecting air pipe 15. The pretreatment tank 11 is set on the ground, and two guide rails 12 are symmetrically fixedly installed on the top and bottom of the inner wall of the pretreatment tank 11.

[0061] The pretreatment tank 11 is connected to two sides by a gas supply mechanism 6. The gas supply mechanism 6 includes an air pipe 601, which is connected to both sides of the pretreatment tank 11. The top of the air pipe 601 is connected to a solenoid valve 603 through a gas supply pipe 602. The bottom of the solenoid valve 603 is connected to a gas storage tank 604 through a connecting pipe. The gas storage tank 604 is located on the ground.

[0062] A filter plate mechanism 7 is slidably installed inside the four guide rails 12. The filter plate mechanism 7 includes a filter plate 701, which is slidably installed inside the four guide rails 12. A connecting plate 702 is fixedly installed on both sides of the filter plate 701, and a driving block 703 is fixedly installed at the bottom of each of the two connecting plates 702.

[0063] Two pendulum mechanisms 8 are symmetrically and rotatably installed on both sides of the inner wall of the pretreatment tank 11. Each pendulum mechanism 8 includes a first rotating shaft 801 and a second rotating shaft 804. The first rotating shaft 801 and the second rotating shaft 804 are respectively rotatably installed on both sides of the inner wall of the pretreatment tank 11. A first pendulum 802 is fixedly installed on the surface of the first rotating shaft 801 through a connecting rod. A first convex shaft 803 is fixedly installed on one end of the first rotating shaft 801. A second pendulum 805 is fixedly installed on the surface of the second rotating shaft 804 through a connecting rod. A second convex shaft 806 is fixedly installed on one end of the second rotating shaft 804. Two drive blocks 703 are respectively adapted to and installed with the two first convex shafts 803 and the two second convex shafts 806.

[0064] A take-up coil 13 is symmetrically fixedly installed at the bottom of the inner wall of the pretreatment tank 11. The outlet ends of the two take-up coils 13 are fixedly connected to one side of the filter plate 701. A stop block 14 is symmetrically fixedly installed on the top of the two guide rails 12 located at the bottom of the inner wall of the pretreatment tank 11. The four stop blocks 14 are adapted to the filter plate 701.

[0065] Air baffles 16 are fixedly installed on both sides of the filter plate 701. The two air baffles 16 are adapted to the pretreatment tank 11. A switch 17 is fixedly installed on one side of the inner wall of the pretreatment tank 11. The air baffles 16 are adapted to the switch 17.

[0066] In actual use, the activated carbon box 904 has ventilation holes; the end of the vent pipe 902 is connected to a negative pressure device.

[0067] The working principle of the air pollution control device provided in this embodiment is as follows:

[0068] First, the roasting gas is introduced from the left side of the pretreatment tank 11. After entering, the roasting gas enters the interior of the pretreatment tank 11 and normally passes through the filter plate 701 to filter solid dust impurities. The filtered gas then goes to the interior of the tower body 1 for deacidification treatment through the connecting gas pipe 15.

[0069] Then, after the roasting gas is processed, it is discharged from the exhaust pipe 3 and discharged into the purification tank 901 through the connecting gas pipe 2 18. After passing through the demister plate 903, the entrained droplets and mist slurry are removed. The activated carbon box 904 efficiently adsorbs the trace acidic gases that are difficult to completely remove in the spray tower. At the same time, it adsorbs odor molecules and finally discharges through the exhaust pipe 902 in compliance with standards.

[0070] When the filter plate 701 has been used for a long time and the gas input into the pretreatment tank 11 is excessive and the temperature is too high, the gas filtration efficiency of the filter plate 701 decreases, and the thrust from the gas gradually increases. At this time, the filter plate 701 is limited by the guide rail 12 and moves to the position of the connecting air pipe 15. The air baffle 16, which moves with the filter plate 701, also moves. At this time, the passage for air input from the air pipe 601 to the pretreatment tank 11 is opened. After the air baffle 16 moves, it simultaneously contacts the switch 17. After the switch 17 is activated, the solenoid valve 603 is opened. The air storage tank 604 inputs clean air into the interior of the pretreatment tank 11 through the air supply pipe 602, the solenoid valve 603, and the air pipe 601. As the filter plate 701 continues to move, it cools and mixes the roasting gas. The connecting plate 702 drives the drive block 703 to contact the first convex shaft 803 and the second convex shaft 806. The first convex shaft 803 and the second convex shaft 806 drive the first rotating shaft 801 and the second rotating shaft 804 to rotate. The first rotating shaft 801 and the second rotating shaft 804 drive the first pendulum 802 and the second pendulum 805 to contact one side of the filter plate 701 to clean solid dust impurities. The stop block 14 limits the movement. When the drive block 703 disengages from the first convex shaft 803 and the second convex shaft 806, the first pendulum 802 and the second pendulum 805 swing back and forth once to clean solid dust impurities again.

[0071] Then, when the input roasting gas decreases, the filter plate 701 restores its original cleaning efficiency and automatically resets to the middle position. At the same time, the switch 17 closes the solenoid valve 603 and the two air baffles 16 close the input air passage. When the roasting gas stops being input, it is driven back to the initial position by the take-up coil 13 and is still limited by the two stop blocks 14. At this time, the drive block 703 on the opposite side contacts the pendulum mechanism 8 at the initial position again and cleans the filter plate 701 again. During the movement of the filter plate 701, the filter plate 701 and the air baffles 16 work together to remove solid impurities from the inner wall of the pretreatment tank 11. After long-term use, the solid impurities can be cleaned and recovered manually from the left and right sides of the pretreatment tank 11.

[0072] Compared with related technologies, the air pollution control device provided in this embodiment has the following beneficial effects:

[0073] By setting the filter plate 701 to move dynamically back and forth, when the gas input into the pretreatment tank 11 is too high or the temperature is too high after long-term use, the air passage is opened by the air baffle 16 and the air is input into the gas storage tank 604 through the trigger switch 17 to cool down and mix the high-temperature gas to stabilize the gas temperature and protect the filter plate 701. The first pendulum 802 and the second pendulum 805 are driven by the drive block 703 to swing and automatically clean the filter plate 701, effectively removing dust and restoring filtration efficiency. At the same time, the air baffle 16 cleans the inner wall of the pretreatment tank 11 to remove solid impurities. When the input roasting gas is reduced, the filter plate 701 restores its original cleaning efficiency, closes the air passage and the solenoid valve 603 and resets the filter plate 701, reducing energy consumption and manual intervention. Combined with the subsequent adsorption of the demister plate 903 and the activated carbon box 904, the efficient removal of dust, acidic gas and odor molecules in the roasting gas is ensured, and the emission standard is met. This improves the reliability, continuity and environmental protection of the entire treatment process.

[0074] A method for lithium extraction and co-production of cryolite and lithium phosphate

[0075] A method for lithium extraction and co-production of cryolite and lithium phosphate includes the following steps:

[0076] S1: Take lumpy lepidolite ore, crush it with a jaw crusher, weigh a certain amount of crushed raw material and transfer it to a ball mill jar, add deionized water, perform wet grinding to suppress dust, set the ball mill to a certain speed for grinding, and after grinding, pass the slurry through a 200-mesh standard sieve. The coarse particles on the sieve are returned to the ball mill jar for secondary grinding, and the fine slurry under the sieve is filtered by a vacuum filtration device to obtain a filter cake. The filter cake is placed in an oven to dry for a period of time to obtain lepidolite concentrate. The lepidolite concentrate has a water content of ≤5%. Grind it into powder with an agate mortar and pestle, and store it in a sealed container.

[0077] S2: Weigh a certain amount of powdered lepidolite concentrate and mix it with sodium bisulfite. Mix thoroughly and grind with an agate mortar to ensure uniform contact. Transfer the mixture to a corundum crucible, place it in a muffle furnace, set the program, heat to 500℃ at a heating rate of 5℃ / min, hold for a period of time, and allow to cool naturally to room temperature. Grind the calcined product through a 100-mesh sieve using an agate mortar to obtain the calcined material. Seal and store the material. The gas generated during calcination is treated in an air pollution control device to meet emission standards.

[0078] S3: Weigh a certain amount of calcined material, transfer it to a beaker, add deionized water and mix it evenly according to a certain liquid-solid ratio. Heat the water bath to 95°C, set the magnetic stirrer to a certain speed and stir for a period of time. After the leaching is completed, immediately filter the solution and collect the leachate. Wash the filter residue twice with deionized water preheated to 95°C, stirring for 5 minutes each time and then filter it. Combine the washing liquids into a volumetric flask.

[0079] S4: Take a certain amount of leachate and concentrate it using a rotary evaporator. ,reduce Dosage: Transfer the concentrated solution to a beaker, turn on the magnetic stirrer, and use 1 mol / L The solution was titrated, with the pH recorded after each addition of a certain amount of solution, until pH = 9.00 ± 0.05. After titration, the solution was stirred in a 30°C constant temperature water bath for a period of time to obtain a mixture. The mixture was transferred to a centrifuge tube and centrifuged at a certain speed to obtain the supernatant. The supernatant was collected in three batches. The precipitated impurities were washed three times with deionized water and dried to obtain cryolite as the main phase. The sediment;

[0080] S5: Take a certain amount of the supernatant, transfer it to a beaker, heat it in a water bath to 90℃, stir magnetically at 200-400 rpm, and slowly add 1 mol / L... Add the solution dropwise at a rate of 1 mL per minute to avoid localized overconcentration. After the addition is complete, continue stirring for a period of time. Filter the reaction solution using a glass frit funnel. Wash the precipitate three times with deionized water preheated to 95°C, filtering for 10 minutes each time to ensure thorough washing. The precipitate formed after filtration was transferred to a ceramic boat and dried in an oven at 105°C to obtain lithium phosphate. product.

[0081] First Embodiment

[0082] First, the raw lepidolite ore was crushed to ≤5mm using a jaw crusher. 20g of the crushed lepidolite ore was weighed and three parallel experiments were conducted. The crushed lepidolite ore was transferred to a ball mill jar, and 40mL of deionized water was added. The ball mill was set to 300rpm and the grinding time was 2h. The slurry after grinding was passed through a 200-mesh standard sieve. The coarse particles on the sieve were returned to the ball mill jar for secondary grinding. 10mL of water was added and the slurry was ground for another 1h. The fine slurry that passed through the sieve was filtered using a vacuum filtration device to obtain a filter cake. The filter cake was dried in an oven at 105℃ for 2h to obtain lepidolite concentrate. The moisture content of the lepidolite concentrate was ≤5%. It was ground into powder using an agate mortar and pestle and then sealed for storage.

[0083] Then, weigh 10.0g of the above-mentioned powdered lepidolite concentrate and mix it with 25.0g of sodium bisulfate. Mix thoroughly and grind with an agate mortar for 3 minutes to ensure uniform contact. Transfer the mixture to a corundum crucible, place it in a muffle furnace, heat to 500℃ at a heating rate of 5℃ / min, hold for 1 hour, and allow to cool naturally to room temperature. Grind the calcined product through a 100-mesh sieve using an agate mortar to obtain the calcined material. Seal and store the material. Perform three parallel experiments, labeled R1, R2, and R3.

[0084] Then, weigh 31.7g of calcined material, parallel samples R1, R2, and R3, and transfer them to a 500mL beaker. Add 320mL of deionized water, with a liquid-to-solid ratio of 10:1, and perform leaching. Heat the water bath to 95℃, set the magnetic stirrer to 200rpm, and leach for 2 hours. Record the temperature every 30 minutes to ensure temperature stability. After leaching, immediately filter with qualitative filter paper and collect the leachate in a 1000mL volumetric flask. After making up to volume, transfer it to a polyethylene bottle. Wash the filter residue twice with 50mL of 95℃ deionized water, stirring for 5 minutes each time, and then filter. Combine the washing liquids into a volumetric flask.

[0085] Then, take 420 mL of the leachate, and use parallel samples R1, R2, and R3 to concentrate to 170 mL using a rotary evaporator at 60 °C for enrichment. ,reduce Dosage: Transfer the concentrate to a 250 mL beaker, turn on the magnetic stirrer at 150 rpm, and use 1 mol / L... The solution was titrated, with the pH recorded after each 0.5 mL drop until pH = 9.00 ± 0.05. After titration, the solution was stirred in a 30℃ constant temperature water bath for 1 h to obtain a mixture. The mixture was transferred to a centrifuge tube and centrifuged at 4000 rpm for 10 min to obtain the supernatant. The supernatant was collected in three batches of 50 mL each, labeled P1, P2, and P3. The precipitated impurities were washed three times with 10 mL of deionized water, and the mixture was centrifuged and dried to obtain cryolite as the main phase. The sedimentation.

[0086] Finally, take 50mL × 3 = 150mL of the supernatant, and make parallel samples P1, P2, and P3. Transfer the mixture to a 250mL beaker, heat it in a water bath to 90℃, and stir magnetically at 200rpm. Based on the supernatant... The concentration, according to For an excess of 10%, take 1 mol / L. The solution was slowly added to the supernatant, and stirring continued for 2 hours after the addition was complete. The reaction solution was filtered through a glass frit funnel. The precipitate was washed three times with 10 mL of deionized water preheated to 95°C, filtering for 5 minutes each time to ensure thorough washing. The precipitate formed after filtration was transferred to a ceramic boat, which was then dried in an oven at 105°C for 2 hours to obtain lithium phosphate. The parallel samples of the products are marked as L1, L2, and L3.

[0087] Compared with related technologies, the method for lithium extraction and co-production of cryolite and lithium phosphate provided by this invention has the following beneficial effects:

[0088] The process of extracting lithium from lepidolite concentrate by adopting a sodium bisulfate roasting-water leaching process reduces roasting temperature and energy consumption. This bisulfate roasting process provides higher lithium extraction efficiency, achieving an extremely low total lithium loss rate (<8.4%), and also increases the high-value-added byproduct cryolite during lithium extraction. The production of high-quality lithium phosphate and its high recovery rate reduce waste emissions, aligning with the principles of green chemistry.

[0089] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An air pollution control device, characterized in that, include: The tower structure placed on the ground; An air inlet pipe, the outlet end of which passes through one side of the tower body and extends into the interior; An exhaust pipe, which connects to the top of the tower body; The spraying mechanism includes a return pipe connected to the bottom of the tower body. One end of the return pipe is connected to a spray box located on the ground. A lift pump is fixedly installed on the top of the spray box. The input end of the lift pump is connected to the interior of the spray box via a suction pipe. The output end of the lift pump is connected to a lift pipe. The end of the lift pipe penetrates the outer wall of the tower body and extends into the interior. A sprinkler is connected to the end of the lift pipe. Several spray holes are provided at the bottom of the sprinkler. A packing disc is fixedly installed on the inner wall of the tower body, and spherical packing is placed on top of the packing disc.

2. The air pollution control device according to claim 1, characterized in that, A waterproof plate is fixedly installed at one end of the air inlet pipe inside the tower body via a bracket, and the waterproof plate is adapted to the air inlet pipe.

3. The air pollution control device according to claim 1, characterized in that, The end of the exhaust pipe is connected to a purification mechanism via a second connecting pipe. The purification mechanism includes a purification tank. One side of the purification tank is connected to the end of the exhaust pipe via the second connecting pipe, and the other side of the purification tank is connected to an exhaust pipe. The purification tank is placed on the ground, and a demisting plate and an activated carbon box are fixedly installed inside the purification tank.

4. The air pollution control device according to claim 1, characterized in that, The air intake end of the air intake pipe is connected to a pretreatment tank via a connecting pipe. The pretreatment tank is located on the ground, and two guide rails are symmetrically fixedly installed at the top and bottom of the inner wall of the pretreatment tank.

5. An air pollution control device according to claim 4, characterized in that, The pretreatment tank is connected to two sides by a gas supply mechanism, which includes an air pipe connected to both sides of the pretreatment tank. The top of the air pipe is connected to a solenoid valve through the gas supply pipe, and the bottom of the solenoid valve is connected to a gas storage tank through a connecting pipe. The gas storage tank is located on the ground.

6. The air pollution control device according to claim 5, characterized in that, A filter plate mechanism is slidably installed inside the four guide rails. The filter plate mechanism includes a filter plate, which is slidably installed inside the four guide rails. A connecting plate is fixedly installed on both sides of the filter plate, and a driving block is fixedly installed on the bottom of each of the two connecting plates.

7. An air pollution control device according to claim 6, characterized in that, Two pendulum mechanisms are symmetrically and rotatably installed on both sides of the inner wall of the pretreatment tank. Each pendulum mechanism includes a first rotating shaft and a second rotating shaft. The first rotating shaft and the second rotating shaft are respectively rotatably installed on both sides of the inner wall of the pretreatment tank. A first pendulum is fixedly installed on the surface of the first rotating shaft through a connecting rod, and a first convex shaft is fixedly installed on one end of the first rotating shaft. A second pendulum is fixedly installed on the surface of the second rotating shaft through a connecting rod, and a second convex shaft is fixedly installed on one end of the second rotating shaft. Two drive blocks are respectively adapted and installed to the two first convex shafts and the two second convex shafts.

8. An air pollution control device according to claim 6, characterized in that, The bottom of the inner wall of the pretreatment tank is symmetrically fixed with a take-up device, and the outlet ends of the two take-up devices are fixedly connected to one side of the filter plate. The top of the two guide rails located at the bottom of the inner wall of the pretreatment tank is symmetrically fixed with abutments, and the four abutments are adapted to the filter plate.

9. An air pollution control device according to claim 7, characterized in that, Air baffles are fixedly installed on both sides of the filter plate. The two air baffles are adapted to the pretreatment tank. A switch is fixedly installed on one side of the inner wall of the pretreatment tank. The air baffles are adapted to the switch.

10. A method for lithium extraction and co-production of cryolite and lithium phosphate, requiring the use of an air pollution control device as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Take lumpy lepidolite ore, crush it with a jaw crusher, weigh a certain amount of crushed raw material and transfer it to a ball mill jar, add deionized water, perform wet grinding to suppress dust, set the ball mill to a certain speed for grinding, and after grinding, pass the slurry through a 200-mesh standard sieve. The coarse particles on the sieve are returned to the ball mill jar for secondary grinding, and the fine slurry under the sieve is filtered by a vacuum filtration device to obtain a filter cake. The filter cake is placed in an oven to dry for a period of time to obtain lepidolite concentrate. The lepidolite concentrate has a water content of ≤5%. Grind it into powder with an agate mortar and pestle, and store it in a sealed container. S2: Weigh a certain amount of powdered lepidolite concentrate and mix it with sodium bisulfite. Mix thoroughly and grind with an agate mortar to ensure uniform contact. Transfer the mixture to a corundum crucible, place it in a muffle furnace, set the program, heat to 500℃ at a heating rate of 5℃ / min, hold for a period of time, and allow to cool naturally to room temperature. Grind the calcined product through a 100-mesh sieve using an agate mortar to obtain the calcined material. Seal and store the material. The gas generated during calcination is treated in an air pollution control device to meet emission standards. S3: Weigh a certain amount of calcined material, transfer it to a beaker, add deionized water and mix it evenly according to a certain liquid-solid ratio. Heat the water bath to 95°C, set the magnetic stirrer to a certain speed and stir for a period of time. After the leaching is completed, immediately filter the solution and collect the leachate. Wash the filter residue twice with deionized water preheated to 95°C, stirring for 5 minutes each time and then filter it. Combine the washing liquids into a volumetric flask. S4: Take a certain amount of leachate and concentrate it using a rotary evaporator. ,reduce Dosage: Transfer the concentrated solution to a beaker, turn on the magnetic stirrer, and use 1 mol / L The solution was titrated, with the pH recorded after each addition of a certain amount of solution, until pH = 9.00 ± 0.

05. After titration, the solution was stirred in a 30°C constant temperature water bath for a period of time to obtain a mixture. The mixture was transferred to a centrifuge tube and centrifuged at a certain speed to obtain the supernatant. The supernatant was collected in three batches. The precipitated impurities were washed three times with deionized water and dried to obtain cryolite as the main phase. The sediment; S5: Take a certain amount of the supernatant, transfer it to a beaker, heat it in a water bath to 90℃, stir magnetically at 200-400 rpm, and slowly add 1 mol / L... Add the solution dropwise at a rate of 1 mL per minute to avoid localized overconcentration. After the addition is complete, continue stirring for a period of time. Filter the reaction solution using a glass frit funnel. Wash the precipitate three times with deionized water preheated to 95°C, filtering for 10 minutes each time to ensure thorough washing. The precipitate formed after filtration was transferred to a ceramic boat and dried in an oven at 105°C to obtain lithium phosphate. product.

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