Method for cooperatively roasting aluminum slag and lepidolite to extract lithium and reaction treatment device

Abstract

This invention provides a method and reaction processing apparatus for lithium extraction through co-calcination of aluminum slag and lepidolite, relating to the field of battery material preparation. The method includes the following steps: S1, crushing a lepidolite sample to a particle size ≤75μm and crushing the aluminum slag to a particle size ≤100μm; S2, using a reaction processing device to add the crushed aluminum slag to an alkaline solution for desilication treatment, obtaining desilicationized aluminum slag after solid-liquid separation and drying; S3, mixing the lepidolite and desilicationized aluminum slag uniformly in a specified ratio, adding an alkaline additive, and calcining at 800~900℃. The method for lithium extraction through co-calcination of aluminum slag and lepidolite provided by this invention removes some SiO2 from the aluminum slag through alkaline treatment, effectively enhancing its destructive activity against the lepidolite structure. Co-calcination is achieved at lower temperatures, significantly improving the lithium leaching rate, reducing energy consumption and acid consumption, and simultaneously realizing the resource utilization of industrial solid waste aluminum slag.

Description

Technical Field

[0001] This invention relates to the field of battery material preparation, and in particular to a method and reaction processing apparatus for lithium extraction by synergistic roasting of aluminum slag and lepidolite. Background Technology

[0002] Lithium resources are a key strategic mineral supporting the development of the global new energy industry and are widely used in many high-tech fields such as lithium-ion batteries and energy storage systems. Among them, lepidolite, as a lithium mineral resource, has abundant reserves and wide distribution. However, due to its stable crystal structure and complex lithium element occurrence mode, it is difficult to achieve efficient extraction by conventional wet or alkaline methods, which limits its resource utilization efficiency.

[0003] Currently, the sulfuric acid roasting method is commonly used in industrial production to extract lithium. This involves mixing lepidolite with sulfate and roasting it at a high temperature of 800-1000℃ to destroy its structure and convert lithium into soluble lithium salts, which are then extracted by water or alkali leaching. Although this method has a high lithium leaching rate, it also has significant drawbacks: the high-temperature roasting process is energy-intensive and costly. Therefore, developing new technologies for low-energy consumption and high-efficiency lithium extraction has become a key research direction for the high-value utilization of lepidolite.

[0004] Co-roasting, as a novel lithium extraction technology, has shown promising prospects in reducing roasting temperature and improving lithium migration efficiency by introducing auxiliary minerals or additives to regulate reaction behavior. Aluminum slag is a high-yield solid waste from the aluminum industry, rich in active alumina and alkaline components, but it also contains a large amount of inert SiO2, which easily forms insoluble lithium silicates with lithium during roasting, thereby inhibiting lithium release. There is room for development in how to utilize aluminum slag and lepidolite for lithium extraction and achieve solid waste utilization.

[0005] Therefore, it is necessary to provide a method for lithium extraction by co-roasting aluminum slag and lepidolite to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a method for lithium extraction by co-roasting aluminum slag and lepidolite, which solves the problem of how to extract lithium by co-roasting aluminum slag and lepidolite and realize the utilization of solid waste.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for lithium extraction by co-roasting aluminum slag and lepidolite, comprising the following steps:

[0008] S1. Crush the lepidolite sample to a particle size ≤75μm and the aluminum slag to a particle size ≤100μm;

[0009] S2. Using reaction processing equipment, the crushed aluminum slag is added to an alkaline solution for desilication treatment. After solid-liquid separation and drying, desilication aluminum slag is obtained.

[0010] S3. Mix lepidolite and desiliconized aluminum slag evenly in a certain proportion, add alkaline additives, and calcine at 800~900℃.

[0011] S4. Using a reaction processing device, the calcined product is added to deionized water, and after stirring, leaching, and filtration, a lithium-containing filtrate is obtained.

[0012] S5. The obtained lithium-containing filtrate is used to prepare battery-grade lithium carbonate products.

[0013] Preferably, the lithium oxide content of the lepidolite sample in S1 is 1.5~2.0%.

[0014] Preferably, the liquid-solid ratio of aluminum slag to alkaline solution in S2 is 1:1 to 5:1, and the alkaline solution is one of sodium hydroxide, calcium hydroxide, and potassium hydroxide, with an alkaline concentration of 20% to 30%.

[0015] Preferably, the mixing ratio of lepidolite to desilication aluminum slag in S3 is 5:1 to 10:1, and the alkaline additive is one of Na2CO3 and Na2S.

[0016] The present invention also provides a reaction processing apparatus for use in steps S2 and S4 of the method for co-roasting and extracting lithium from aluminum slag and lepidolite.

[0017] Includes: control box;

[0018] A reaction cylinder is mounted on the mounting plate of the control box, and a stirring device is provided on the reaction cylinder;

[0019] A drying filter box, wherein the liquid inlet of the drying filter box is connected to the discharge end of the reaction cylinder through a valve, and an air inlet box and an air outlet pipe are respectively connected to both sides of the drying filter box;

[0020] The filter box includes a box body, a filter element, and two sealing plates. The filter element is detachably disposed in the box body, and the two sealing plates are installed on the top two sides of the box body to seal the air inlet box and the air outlet pipe, respectively.

[0021] The box body has an air inlet and an air outlet on each side, and the air inlet and air outlet are respectively located below the air inlet box and the air outlet pipe.

[0022] A lifting cylinder, used to raise and lower the box body;

[0023] A heating device is provided, comprising a heating jacket, an air inlet pipe, and a return pipe. The heating jacket is fitted over the reaction cylinder, and a partition is installed inside the heating jacket. The air inlet pipe includes an air supply pipe, a first branch pipe, and a second branch pipe. One end of the air supply pipe is connected to the first and second branch pipes via a tee pipe. Both the first branch pipe and the return pipe communicate with the heating jacket and are located on opposite sides of the partition. A valve is installed on the first branch pipe.

[0024] The second branch pipe is connected to the air inlet box, and the end of the air outlet pipe away from the drying filter box is connected to the heating jacket.

[0025] Preferably, the air inlet is provided with an upper air inlet and a lower air inlet, and the upper air inlet and the lower air inlet are located above and below the filter element, respectively.

[0026] Preferably, the reaction cylinder includes a cylinder body and a cylinder cover, the cylinder cover is sleeved on the top of the cylinder body, the heating sleeve is sleeved on the cylinder body, and the reaction processing device further includes a lifting cylinder for lifting the cylinder cover.

[0027] Preferably, the stirring device includes a connecting plate, a motor, a stirring shaft, and stirring blades. The connecting plate connects the output end of the lifting cylinder and the cylinder cover. The motor is mounted on the connecting plate. One end of the stirring shaft is mounted on the output end of the motor, and the other end passes through the connecting plate and the cylinder cover in sequence before connecting to the stirring blades.

[0028] Preferably, the bottom end of the stirring shaft is provided with a square groove, and a material turning assembly is provided inside the box. The material turning assembly includes a rotating shaft, a square shaft, two connecting rods and multiple material turning rods. The rotating shaft is rotatably installed at the center of the box, the square shaft is installed at the top of the rotating shaft and located below the square groove, the two connecting rods are respectively installed on both sides of the rotating shaft, and the multiple material turning rods are installed at intervals at the bottom of the connecting rods, wherein the material turning rods at the bottom of the two connecting rods are staggered.

[0029] When the valve is opened, the lifting cylinder raises the box body, so that the air inlet and the air outlet are connected to the air inlet box and the air outlet pipe respectively, and the square shaft is inserted into the square groove.

[0030] Preferably, the stirring device further includes a conical block, which is installed on the stirring shaft and located below the stirring blades, and the conical block is suspended above the discharge port of the cylinder, the diameter of the conical block being the same as the diameter of the discharge port.

[0031] Compared with related technologies, the method for lithium extraction by co-roasting aluminum slag and lepidolite provided by the present invention has the following beneficial effects:

[0032] This invention provides a method for lithium extraction through co-calcination of aluminum slag and lepidolite. The method removes some SiO2 from the aluminum slag through alkaline treatment, effectively enhancing its destructive activity against the lepidolite structure. Co-calcination is achieved at 800-900℃, significantly improving lithium leaching rate, reducing energy and acid consumption, exhibiting good environmental adaptability and potential for comprehensive resource utilization, and simultaneously realizing the resource utilization of industrial solid waste aluminum slag. Attached Figure Description

[0033] Figure 1 A flowchart illustrating the steps of the method for lithium extraction by co-roasting aluminum slag and lepidolite provided by the present invention.

[0034] Figure 2 Comparative bar charts of Comparative Examples 1-4 provided for this invention;

[0035] Figure 3 This is a schematic diagram of the reaction processing apparatus provided by the present invention;

[0036] Figure 4 for Figure 3 A partial cross-sectional view of the reaction processing apparatus shown;

[0037] Figure 5 This is a schematic diagram of the filter box provided by the present invention;

[0038] Figure 6 A cross-sectional view of the filter cartridge provided by the present invention;

[0039] Figure 7 A schematic diagram showing the state of a square shaft inserted into a square groove according to the present invention;

[0040] Figure 8 A schematic diagram showing the state of the conical block sealing the discharge port of the cylinder provided by the present invention;

[0041] Figure 9 for Figure 8 The enlarged schematic diagram of part A is shown.

[0042] Numbering on the map:

[0043] 1. Control box; 11. Mounting plate;

[0044] 2. Reaction cylinder; 21. Cylinder body; 22. Cylinder cover; 23. Valve; 231. Valve plate;

[0045] 3. Drying filter box; 31. Air inlet box; 32. Air outlet pipe; 33. Support frame; 301. Liquid outlet pipe;

[0046] 4. Heating device; 41. Heating jacket; 42. Air inlet pipe; 43. Return pipe; 421. Air supply pipe; 422. First branch pipe; 423. Second branch pipe; 401. Partition plate;

[0047] 5. Filter box; 51. Box body; 52. Filter element; 53. Sealing plate; 54. Air inlet; 55. Air outlet; 541. Upper air outlet; 542. Lower air outlet;

[0048] 6. Stirring device; 61. Connecting plate; 62. Motor; 63. Stirring shaft; 64. Stirring blades; 65. Conical block; 631. Square groove;

[0049] 7. Flipping assembly; 71. Rotating shaft; 72. Square shaft; 73. Connecting rod; 74. Flipping rod;

[0050] 8. Lifting cylinder;

[0051] 9. Lifting cylinder. Detailed Implementation

[0052] 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 them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] This invention provides a method for lithium extraction by co-roasting aluminum slag and lepidolite.

[0054] Please refer to the following: Figure 1 In one embodiment of the present invention, the method for co-roasting aluminum slag and lepidolite to extract lithium includes the following steps:

[0055] S1. Crush the lepidolite sample to a particle size ≤75μm and the aluminum slag to a particle size ≤100μm;

[0056] S2. Using reaction processing equipment, the crushed aluminum slag is added to an alkaline solution for desilication treatment. After solid-liquid separation and drying, desilication aluminum slag is obtained.

[0057] S3. Mix lepidolite and desiliconized aluminum slag evenly in a certain proportion, add alkaline additives, and calcine at 800~900℃.

[0058] S4. Using a reaction processing device, the calcined product is added to deionized water, and after stirring, leaching, and filtration, a lithium-containing filtrate is obtained.

[0059] S5. The obtained lithium-containing filtrate is used to prepare battery-grade lithium carbonate products.

[0060] This invention removes some SiO2 from aluminum slag through alkaline treatment, effectively enhancing its destructive activity against lepidolite structures. Co-calcination at 800-900℃ significantly improves lithium leaching rate, reduces energy and acid consumption, exhibits good environmental adaptability and resource utilization potential, and simultaneously achieves the resource utilization of industrial solid waste aluminum slag.

[0061] Preferably, the lithium oxide content of the lepidolite sample in S1 is 1.5–2.0%.

[0062] Preferably, the liquid-solid ratio of aluminum slag to alkaline solution in S2 is 1:1 to 5:1, and the alkaline solution is one of sodium hydroxide, calcium hydroxide, and potassium hydroxide, with an alkaline concentration of 20% to 30%.

[0063] Preferably, the mixing ratio of lepidolite to desilication aluminum slag in S3 is 5:1 to 10:1, and the alkaline additive is one of Na2CO3 and Na2S.

[0064] The present invention also provides the following embodiments and comparative examples:

[0065] Example 1

[0066] Industrial aluminum slag was desiliconized by 5 wt% NaOH solution with a solid-liquid ratio of 1:3, a reaction temperature of 95℃, and a reaction time of 2h. Lithium mica was mixed with the filtered product at a mass ratio of 6:1, and 5% Na2CO3 was added as an auxiliary agent. The mixture was calcined at 850℃ for 1h, and the calcined product was then leached in water at 80℃ for 1h to extract lithium.

[0067] Example 2:

[0068] The alkaline solution for desilication of aluminum slag was 5% KOH, and other experimental parameters and procedures were the same as in Example 1.

[0069] Example 3:

[0070] The alkaline calcination agent was 5% Na2S, and other experimental parameters and procedures were the same as in Example 1.

[0071] Example 4:

[0072] Lithium mica was mixed with the filtered mica at a mass ratio of 10:1, and other experimental parameters and procedures were the same as in Example 1.

[0073] Comparison of data from Examples 1-4 shows that the aluminum slag desilication-lithium mica co-roasting lithium extraction process provided by this invention, through systematic optimization of the aluminum slag desilication method, roasting aid type, raw material ratio, and roasting temperature, significantly improves lithium extraction efficiency and demonstrates strong energy-saving and solid waste utilization potential. The comparison of the examples shows that using sodium hydroxide for aluminum slag desilication treatment is superior to using potassium hydroxide, indicating that Na... +The process is more conducive to the effective removal of SiO2 in the desilication reaction, and the resulting highly active aluminum slag can react more fully with lepidolite during roasting, promoting the release of lithium. Regarding the type of additives, both sodium carbonate and sodium sulfide, two alkaline substances, showed good synergistic roasting effects, indicating that the process has a certain degree of additive adaptability. However, carbonate additives are more stable during roasting and have no reducing side reactions, making them more suitable for the promotion of green processes.

[0074] Furthermore, a comparison of the mass ratio of lepidolite to aluminum slag reveals that appropriately controlling the amount of aluminum slag added has a crucial impact on the synergistic effect of roasting. Insufficient aluminum slag hinders the full progress of the structural destructive reaction, leading to a significant decrease in lithium leaching rate. This indicates that aluminum slag not only acts as a mineral phase modifier but also participates in the structural activation process. Therefore, this process demonstrates significant advantages in lithium extraction efficiency, energy conservation and emission reduction, and the co-utilization of solid waste, and has broad prospects for industrial application.

[0075] Comparative Example 1:

[0076] Aluminum slag was directly mixed with lepidolite and roasted without desiliconization treatment. Other experimental parameters and steps were the same as in Example 1.

[0077] Comparative Example 2:

[0078] The lepidolite was directly roasted without adding the treated aluminum slag, and other experimental parameters and steps were the same as in Example 1.

[0079] Comparative Example 3:

[0080] No calcination alkaline additives were added, and other experimental parameters and procedures were the same as in Example 1.

[0081] Comparative Example 4:

[0082] Lithium mica was mixed with commonly used calcination additives calcium sulfate and sodium sulfate at a dosage of 5%. Other experimental parameters and steps were the same as in Example 1.

[0083] like Figure 2Comparative Examples 1-4 further validated the significant role of key steps in the proposed process in improving lithium leaching rate through comparative experiments. First, in Comparative Example 1, using undesiliconized aluminum slag directly in the roasting process resulted in a significantly lower lithium leaching effect compared to the example after desiliconization treatment. This indicates that the unremoved SiO2 in the aluminum slag readily forms an insoluble lithium silicate mesophase with lithium, inhibiting lithium migration and release. The desiliconization treatment significantly enhanced the reactivity of Al2O3 and alkaline oxides in the aluminum slag, verifying the necessity of the pretreatment step in improving the overall roasting effect. In Comparative Example 2, without adding any aluminum slag and only roasting the lepidolite matrix, the leaching effect was even worse, indicating that single roasting cannot fully destroy its stable crystal structure. This also demonstrates that the aluminum slag plays an important role in structural activation and synergistic reaction in this process.

[0084] In the comparison of the effects of additives, Comparative Example 3, without the addition of alkaline additives, showed a lower lithium leaching rate than the examples containing additives such as Na2CO3 or Na2S, indicating that an alkaline environment has a significant promoting effect on lithium migration and regulating mineral phase transformation. While Comparative Example 4 used traditional roasting additives such as calcium sulfate and sodium sulfate, and although the leaching rate was relatively high, it still suffered from problems such as strong corrosivity and complex byproduct treatment compared to the low-temperature roasting and solid waste co-utilization pathway of this invention. Therefore, the low-temperature co-roasting process proposed in this invention, using desilication aluminum slag as an activation carrier and combined with mild alkaline additives, not only outperforms conventional additive systems in lithium extraction efficiency but also has stronger comprehensive advantages in terms of environmental protection and resource utilization.

[0085] The process of using the lithium-containing filtrate obtained in step S5 of this invention to prepare battery-grade lithium carbonate products specifically includes the following steps:

[0086] S51. Add NaOH / lime milk to adjust the pH to 10.5~11.5, heat to 80–90℃, stir for 1–2 hours, and filter to remove iron, aluminum and silicon elements from the solution;

[0087] S52. Add Ca(OH)2 / CaCl2 to the filtered solution and control F. - :Ca 2+ ≈1:1.2, stir for 30–60 min, and filter to remove fluorine from the solution;

[0088] S53. Extract the filtered solution to remove calcium and magnesium elements. β-diketone / benzoyltrifluoroacetone is used as the extractant, and tributyl phosphate (TBP) is used for modification. 2-5 stages of countercurrent extraction are used.

[0089] S54, The extracted lithium solution is evaporated and concentrated to Li +The concentration was 25–35 g / L, and then CO2 was bubbled into the solution while maintaining the temperature at 90°C and pH at 8.5–9.0. After the reaction was complete, the solution was filtered and washed to obtain crude lithium carbonate.

[0090] S55. Crude lithium carbonate is slurried with pure water, and CO2 is introduced to generate LiHCO3. Insoluble impurities are filtered out, and then LiHCO3 is decomposed at 60~80℃ to precipitate Li2CO3 crystals. After filtration, washing and drying, battery-grade lithium carbonate material is obtained.

[0091] The present invention also provides a reaction processing apparatus.

[0092] The reaction processing device provided by this invention is used in steps S2 and S4 of the method for co-calcining aluminum slag and lepidolite to extract lithium. It is mainly used for solid-liquid (or liquid-liquid) mixing reactions, solid-liquid separation, stirring leaching, and material drying. Of course, this reaction processing device can also be used for other similar solid-liquid or liquid-liquid mixing reactions, such as in the formation of lithium carbonate, where lithium ions react with sodium carbonate solution to form crude lithium carbonate precipitate. The reaction processing device provided by this invention is preferably used in small-scale preparation scenarios such as laboratories.

[0093] Please see Figures 3 to 5 A reaction processing device, comprising: a control box 1;

[0094] The reaction cylinder 2 is mounted on the mounting plate 11 of the control box 1, and the reaction cylinder 2 is equipped with a stirring device 6;

[0095] The drying filter box 3 has its liquid inlet end connected to the discharge end of the reaction cylinder 2 via valve 23. The drying filter box 3 has an air inlet box 31 and an air outlet pipe 32 connected to its two sides respectively.

[0096] The filter box 5 includes a box body 51, a filter element 52 and two sealing plates 53. The filter element 52 is detachably disposed inside the box body 51. The two sealing plates 53 are installed on the top sides of the box body 51 to seal the air inlet box 31 and the air outlet pipe 32 respectively.

[0097] The box body 51 has an air inlet 54 and an air outlet 55 on both sides, and the air inlet 54 and the air outlet 55 are respectively located below the air inlet box 31 and the air outlet pipe 32.

[0098] Lifting cylinder 9, which is used to lift and lower the box body 51;

[0099] Heating device 4 includes a heating jacket 41, an air inlet pipe 42, and a return pipe 43. The heating jacket 41 is fitted onto the reaction cylinder 2, and a partition 401 is installed inside the heating jacket 41. The air inlet pipe 42 includes an air supply pipe 421, a first branch pipe 422, and a second branch pipe 423. One end of the air supply pipe 421 is connected to the first branch pipe 422 and the second branch pipe 423 respectively via a tee pipe. The first branch pipe 422 and the return pipe 43 are both connected to the heating jacket 41 and are located on both sides of the partition 401. A valve is provided on the first branch pipe 422.

[0100] The second branch pipe 423 is connected to the air inlet box 31, and the end of the air outlet pipe 32 away from the drying filter box 3 is connected to the heating jacket 41.

[0101] In this embodiment, the heating device 4 also includes a fan, a heater, a filter, and a temperature sensor. The output end of the filter, the fan, and the heater are connected in sequence through pipes. The air supply pipe 421 is connected to the output end of the heater, and the return pipe 43 is connected to the input end of the filter or directly discharges the gas to a designated location. The temperature sensor is installed inside the heating jacket 41, and a temperature sensor (not shown) is installed inside the reaction cylinder 2. By detecting the temperature, the heater adjusts the heating temperature. The filter filters dust and other impurities in the incoming air, and the heating jacket 41 is equipped with a guide plate, a spiral guide vane, etc. (not shown) to make the hot gas evenly surround the heating jacket 41.

[0102] In use, crushed aluminum slag and alkaline solution are added to the reaction cylinder 2. The aluminum slag and alkaline solution are stirred and mixed by the stirring device 6. The heating device 4 heats the cylinder to the preset temperature. The hot air flows into the heating jacket 41 through the air supply pipe 421 and the first branch pipe 422 to heat the reaction cylinder 2. When the reaction is completed, the valve 23 is opened and the solution enters the drying filter box 3. It then enters the filter box 5 and filters the solids in the solution through the filter element 52. The solution is discharged through the liquid outlet pipe 301 of the drying filter box 3.

[0103] Subsequently, the valve on the first branch pipe 422 is closed, and the lifting cylinder 9 lifts the filter box 5, so that the two sealing plates 53 are separated from the air inlet box 31 and the air outlet pipe 32 respectively, and the air inlet 54 and the air outlet 55 are connected to the air inlet box 31 and the air outlet pipe 32 respectively. At this time, the heating device 4 works, and the hot airflow enters the air inlet box 31 through the air supply pipe 421 and the second branch pipe 423. The hot airflow enters the filter box 5 through the air inlet 54 to dry the material inside the filter box 5. The airflow that takes away the moisture enters the heating jacket 41 through the air outlet pipe 32 and is finally discharged through the return pipe 43.

[0104] Thus, the heating device 4 can be used to heat the reaction cylinder 2 to achieve the preset temperature for the mixing reaction, and can also be used to dry the solid materials after the reaction, simplifying the equipment.

[0105] In step S4, after stirring and leaching, solid-liquid separation can be performed through filter element 52.

[0106] During the drying process, the airflow velocity is 0.5~2 m / s, and the low velocity avoids carrying away solid particles; the drying temperature is preferably 105~120℃; and during drying, valve 23 is closed, and the valve on the liquid outlet pipe 301 at the bottom of the drying filter box 3 is closed to reduce heat loss and keep the drying filter box 3 in a drying state.

[0107] Preferably, a filter cloth (not shown) is provided on the air outlet 55 to prevent a small amount of powder from escaping with the airflow.

[0108] Among them, such as Figure 3 The front of the drying filter box 3 is equipped with a removable sealing door. After drying, the filter box 5 can be removed by removing the sealing door, thereby taking out the filtered solid material; such as Figure 4 Inside the drying filter box 3, a support frame 33 is installed, and the filter box 5 is supported on the support frame 33.

[0109] The lifting cylinder 9 is installed on the top of the drying filter box 3, and its output end passes through the top of the drying filter box 3 and is detachably connected to the box body 51. In one embodiment, an L-shaped shaft is installed at the output end of the lifting cylinder 9, and an assembly block is installed on the filter box 5. The assembly block has an assembly hole. When the filter box 5 is installed in the drying filter box 3, the L-shaped shaft is inserted into the assembly block to realize the function of lifting cylinder 9 to raise and lower filter box 5; at the same time, it facilitates the separation of box body 51 from lifting cylinder 9. In another embodiment, an L-shaped block is installed at the bottom of the lifting cylinder 9, and a corresponding inverted L-shaped block is installed on the filter box 5. When the filter box 5 is installed in the drying filter box 3, the L-shaped block and the inverted L-shaped block engage, thereby realizing the function of lifting cylinder 9 to raise and lower filter box 5.

[0110] The outlet pipe 301 of the drying filter box 3 is connected to a liquid collection container through a pipe. Different reactions use corresponding collection containers to collect the filtrate separately.

[0111] In this embodiment, the filter cloth provided on the filter element 52 and the air outlet 55 is preferably made of polyacrylonitrile filter cloth or PTFE filter cloth, which is resistant to acid and alkali and drying temperature; the inside of the box body 51 is provided with a porous support plate, the filter element 52 is installed on the porous support plate, and the sealing plate 53 is preferably provided with a sealing gasket.

[0112] like Figure 4 The area of ​​filter element 52 is much larger than the cross-sectional area of ​​the outlet pipe of reaction cylinder 2, so that the solution can be dispersed and filtered into filter element 52, and the filtration can be carried out more quickly.

[0113] Please see Figure 6 As a preferred embodiment of this example, the air inlet 54 is provided with an upper air inlet 541 and a lower air inlet 542, and the upper air inlet 541 and the lower air inlet 542 are located above and below the filter element 52, respectively.

[0114] By setting an upper air inlet 541 and a lower air inlet 542 at the air inlet 54, hot air enters through the air inlet 54 and is discharged through the upper air inlet 541 and the lower air inlet 542. This ensures that both the upper and lower sides of the material are dried by hot air, improving drying efficiency. Furthermore, under the action of the fan in the heating device 4, the airflow is discharged through the air outlet 32. Thus, the airflow discharged through the lower air inlet 542 needs to pass through the material before entering the air outlet 32. During the process of the hot airflow passing through the material, the drying efficiency is further improved.

[0115] Please see Figure 4 In this example, the reaction cylinder 2 includes a cylinder body 21 and a cylinder cover 22. The cylinder cover 22 is sleeved on the top of the cylinder body 21, and the heating sleeve 41 is sleeved on the cylinder body 21. The reaction processing device also includes a lifting cylinder 8, which is used to lift the cylinder cover 22.

[0116] By setting the cover 22, the reaction cylinder 2 is kept in a relatively sealed state during use, which better preserves the temperature inside the reaction cylinder 2.

[0117] The lifting cylinder 8 is used to lift the cylinder cover 22 to facilitate opening the cylinder cover 22 and to facilitate the addition of reaction materials into the cylinder body 21.

[0118] As an optional embodiment, a feeding pipe is provided on the cylinder cover 22 for adding reactants, and a valve (not shown) is provided on the feeding pipe.

[0119] Furthermore, an exhaust pipe is installed on the cylinder cover 22 to discharge some of the gases produced during the reaction, and a valve is installed on the exhaust pipe (not shown in the figure).

[0120] Among them, lifting cylinder 8 and lifting cylinder 9 can be pneumatic cylinders, hydraulic cylinders, or electric push cylinders, etc.

[0121] Please refer to it again. Figure 4 In this embodiment, the stirring device 6 includes a connecting plate 61, a motor 62, a stirring shaft 63, and a stirring blade 64. The connecting plate 61 connects the output end of the lifting cylinder 8 and the cylinder cover 22. The motor 62 is mounted on the connecting plate 61. One end of the stirring shaft 63 is mounted on the output end of the motor 62, and the other end passes through the connecting plate 61 and the cylinder cover 22 in sequence and is connected to the stirring blade 64.

[0122] In use, motor 62 drives stirring shaft 63 to rotate, thereby driving stirring blade 64 to rotate and mix the solution.

[0123] By mounting the motor 62 on the cylinder cover 22, the lifting cylinder 8 lifts the cylinder cover 22, causing the stirring device 6 to move out of the reaction cylinder 2, which facilitates the subsequent cleaning of the stirring shaft 63 and the stirring blade 64.

[0124] Preferably, a telescopic rod is installed on the mounting plate 11, and the telescopic end of the telescopic rod is connected to the connecting plate 61. When the lifting cylinder 8 lifts the cylinder cover 22, the telescopic rod extends accordingly, which helps to limit the cylinder cover 22 in the horizontal direction, making the lifting more stable.

[0125] Of course, in other embodiments, the motor 62 can also be directly mounted on the cylinder cover 22, and the connecting plate 61 connects the lifting cylinder 8 and the cylinder cover 22.

[0126] Please see Figure 4 and Figure 5 As an optional embodiment, the bottom end of the stirring shaft 63 is provided with a square groove 631, and a material turning assembly 7 is provided inside the box body 51. The material turning assembly 7 includes a rotating shaft 71, a square shaft 72, two connecting rods 73 and a plurality of material turning rods 74. The rotating shaft 71 is rotatably installed at the center of the box body 51, the square shaft 72 is installed at the top of the rotating shaft 71 and located below the square groove 631, the two connecting rods 73 are respectively installed on both sides of the rotating shaft 71, and the plurality of material turning rods 74 are spaced apart at the bottom of the connecting rods 73, wherein the material turning rods 74 at the bottom of the two connecting rods 73 are staggered.

[0127] When the valve 23 is opened, the lifting cylinder 9 lifts the box body 51, so that the air inlet 54 and the air outlet 55 are connected to the air inlet box 31 and the air outlet pipe 32 respectively, and the square shaft 72 is inserted into the square groove 631.

[0128] The flipping rods 74 at the bottom of the two connecting rods 73 are staggered, that is, when the two connecting rods 73 drive the corresponding flipping rods 74 to rotate, the rotation trajectory of one flipping rod 74 of one connecting rod 73 is located between the rotation trajectories of the two flipping rods 74 of the other connecting rod 73.

[0129] By setting the material-turning component 7, during the filtration stage, when there is a large amount of material being filtered on the filter element 52 and the liquid filtration rate is slow, after the valve 23 is opened, the lifting cylinder 9 lifts the valve box, causing the square shaft 72 to insert into the square groove 631. Figure 7The motor 62 drives the stirring shaft 63 to rotate, the stirring shaft 63 drives the square shaft 72 to rotate, the square shaft 72 drives the two connecting rods 73 to rotate through the rotating shaft 71, and the connecting rods 73 drive the multiple turning rods 74 to rotate to turn the material on the filter element 52, so as to facilitate the solution to pass through the filter element 52, achieve rapid filtration, and make the material more evenly spread on the filter element 52, in preparation for subsequent drying.

[0130] When drying solid materials, after the square shaft 72 is moved upward and inserted into the square groove 631, the air inlet 54 and the air outlet 55 are connected to the air inlet box 31 and the air outlet pipe 32, respectively. During the drying process, the material is turned over by the turning rod 74, thereby increasing the contact area between the material and the hot air and accelerating the drying speed. The turning rods 74 on the two connecting rods 73 are staggered so that the material turned over by the two sets of turning rods 74 is in different positions, so that the material can be turned over more evenly and further accelerate the drying speed.

[0131] In this embodiment, the rotating shaft 71 is rotatably mounted on the porous support plate inside the housing 51, and the filter element 52 is sleeved on the rotating shaft 71. The rotating shaft 71 includes a main shaft and a top shaft, and the top shaft is threadedly connected to the main shaft. The square shaft 72 is fixed on the top shaft. When the filter box 5 is removed later, the top shaft and the main shaft can be threadedly separated first, and then the filter box 5 can be moved out by the main shaft. When the rotating shaft 71 drives the connecting rod 73 to rotate, it is in the same direction as the tightening of the top shaft and the main shaft.

[0132] Furthermore, the top of the square shaft 72 is tapered to prevent material from remaining at the top of the square shaft 72.

[0133] In the initial state, the square shaft 72 and the square groove 631 are aligned. Each time the stirring device 6 works, the motor 62 rotates an integer number of revolutions, so that when it stops, the square shaft 72 and the square groove 631 can be aligned again.

[0134] In one embodiment, a square rod can be fixed inside the drying filter box 3 by a fixing plate. A square groove is opened at the bottom of the rotating shaft 71, and the top of the square rod is inserted into the square groove. When the filter box 5 moves up, the square shaft 72 is inserted into the square groove 631, and the square rod separates from the square groove. Thus, when the square shaft 72 is not inserted into the square groove 631, the square shaft 72 can be prevented from deflecting, ensuring that it is always aligned with the square groove 631.

[0135] The inner cavity of the filter box 5 is circular, and the corresponding filter element 52 is circular, so that when the connecting rod 73 drives the turning rod 74 to rotate, the material on the entire filter element 52 can be turned over; the inner cavity of the filter box 5 can also be set to square, and the corresponding filter element 52 can be set to square.

[0136] In this embodiment, valve 23 includes valve housing, valve plate 231 and driving device. Valve housing is installed between cylinder 21 and drying filter box 3. The pipe part in valve housing connects cylinder 21 and drying filter box 2. Valve plate 231 blocks the pipe. The driving device is used to move valve plate 231 horizontally to block or open the pipe. The driving device can be an electric motor with a lead screw structure, or an electric push cylinder, etc.

[0137] Please see Figure 4 The stirring device 6 further includes a conical block 65, which is installed on the stirring shaft 63 and located below the stirring blade 64. The conical block 65 is suspended above the discharge port of the cylinder 21, and the diameter of the conical block 65 is the same as the diameter of the discharge port.

[0138] The top of the inner wall of the cylinder cover 22 and the top of the cylinder body 21 are spaced apart, allowing the cylinder cover 22 to continue to move down a preset distance and move up the filter box 5, so that the air inlet 54 and the air outlet 55 are connected to the air inlet box 31 and the air outlet pipe 32 respectively. When the square shaft 72 is inserted into the square groove 631, the square groove 631 still has a depth that allows the square shaft 72 to continue to be inserted, and the depth value is not less than the preset distance that the cylinder cover 22 can continue to descend.

[0139] By installing a conical block 65 at the bottom end of the stirring shaft 63, when drying the material on the filter element 52, after the square shaft 72 is inserted into the square groove 631, the lifting cylinder 8 lowers the cylinder cover 22. The cylinder cover 22 drives the stirring device 6 to lower, and the stirring shaft 63 drives the conical block 65 to block the discharge port of the cylinder 21. Figure 8 and Figure 9 At this time, the square groove 631 is further fitted onto the square shaft 72, which greatly reduces the heat loss from the inside of the drying filter box 3 to the cylinder 21 during drying by blocking the discharge port of the cylinder 21.

[0140] Among them, such as Figure 4 A stirring block is installed on the conical block 65, so that the solution near the outlet can be mixed and stirred during the reaction, thereby accelerating the reaction rate.

[0141] The control box 1 is equipped with a control panel, control switches, etc., for controlling the motor 62, lifting cylinder 9, lifting cylinder 8, heating device 4, etc. in the reaction processing device. The lifting cylinder 8 is installed in the control box 1, or it can be installed on the mounting plate 11 or the ground by means of a bracket.

[0142] This equipment can also clean solid materials in the reaction cylinder 2, and then filter and dry the cleaned solid materials in the drying filter box 3.

[0143] The working principle of the reaction processing device provided by this invention is as follows:

[0144] In use, crushed aluminum slag and alkaline solution are added to the reaction cylinder 2. The aluminum slag and alkaline solution are stirred and mixed by the stirring device 6. The heating device 4 heats the cylinder to the preset temperature. The hot air flows into the heating jacket 41 through the air supply pipe 421 and the first branch pipe 422 to heat the reaction cylinder 2. When the reaction is completed, the valve 23 is opened and the solution enters the drying filter box 3. It then enters the filter box 5 and filters the solids in the solution through the filter element 52. The solution is discharged through the liquid outlet pipe 301 of the drying filter box 3.

[0145] Subsequently, the valve on the first branch pipe 422 is closed, and the lifting cylinder 9 lifts the filter box 5, so that the air inlet 54 and the air outlet 55 are connected to the air inlet box 31 and the air outlet pipe 32 respectively. At this time, the heating device 4 works, and the hot airflow enters the air inlet box 31 through the air supply pipe 421 and the second branch pipe 423. The hot airflow enters the filter box 5 through the air inlet 54 to dry the material inside the filter box 5. The airflow that carries away the moisture enters the heating jacket 41 through the air outlet pipe 32 and is finally discharged through the return pipe 43.

[0146] Furthermore, during the filtration stage, when there is a large amount of material being filtered on filter element 52 and the liquid filtration rate is slow, after valve 23 is opened, lifting cylinder 9 lifts the valve box, causing square shaft 72 to insert into square groove 631, such as... Figure 7 The motor 62 drives the stirring shaft 63 to rotate, the stirring shaft 63 drives the square shaft 72 to rotate, the square shaft 72 drives the two connecting rods 73 to rotate through the rotating shaft 71, and the connecting rods 73 drive the multiple turning rods 74 to rotate to turn the material on the filter element 52, so as to facilitate the solution to pass through the filter element 52, achieve rapid filtration, and make the material more evenly spread on the filter element 52, in preparation for subsequent drying.

[0147] When drying solid materials, after the square shaft 72 is moved upward and inserted into the square groove 631, the air inlet 54 and the air outlet 55 are connected to the air inlet box 31 and the air outlet pipe 32, respectively. During the drying process, the material is turned over by the turning rod 74, thereby increasing the contact area between the material and the hot air and accelerating the drying speed. The turning rods 74 on the two connecting rods 73 are staggered so that the material turned over by the two sets of turning rods 74 is in different positions, so that the material can be turned over more evenly and further accelerate the drying speed of the material.

[0148] Thus, the heating device 4 can be used to heat the reaction cylinder 2 to achieve the preset temperature for the mixing reaction, and can also be used to dry the solid materials after the reaction. Furthermore, the two functions can be switched, and the square shaft 72 and the square groove 631 can be assembled. The stirring device 6 drives the turning component 7 to work, simplifying the equipment.

[0149] 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's 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. A method for lithium extraction by co-roasting aluminum slag and lepidolite, characterized in that, Includes the following steps: S1. Crush the lepidolite sample to a particle size ≤75μm and the aluminum slag to a particle size ≤100μm; S2. Using reaction processing equipment, the crushed aluminum slag is added to an alkaline solution for desilication treatment. After solid-liquid separation and drying, desilication aluminum slag is obtained. S3. Mix lepidolite and desiliconized aluminum slag evenly in a certain proportion, add alkaline additives, and calcine at 800~900℃. S4. Using a reaction processing device, the calcined product is added to deionized water, and after stirring, leaching, and filtration, a lithium-containing filtrate is obtained. S5. The obtained lithium-containing filtrate is used to prepare battery-grade lithium carbonate products.

2. The method for lithium extraction by co-roasting aluminum slag and lepidolite according to claim 1, characterized in that, The lithium oxide content of the lepidolite sample in S1 is 1.5~2.0%.

3. The method and reaction processing apparatus for lithium extraction by co-roasting aluminum slag and lepidolite according to claim 1, characterized in that, The liquid-solid ratio of aluminum slag to alkaline solution in S2 is 1:1 to 5:1, and the alkaline solution is one of sodium hydroxide, calcium hydroxide, and potassium hydroxide, with an alkaline concentration of 20% to 30%.

4. The method for lithium extraction by co-roasting aluminum slag and lepidolite according to claim 1, characterized in that, The mixing ratio of lepidolite to desilicationized aluminum slag in S3 is 5:1 to 10:1, and the alkaline additive is one of Na2CO3 and Na2S.

5. A reaction processing apparatus, characterized in that, In steps S2 and S4 of the method for co-roasting and extracting lithium from aluminum slag and lepidolite as described in any one of claims 1-4; Includes: control box; A reaction cylinder is mounted on the mounting plate of the control box, and a stirring device is provided on the reaction cylinder; A drying filter box, wherein the liquid inlet of the drying filter box is connected to the discharge end of the reaction cylinder through a valve, and an air inlet box and an air outlet pipe are respectively connected to both sides of the drying filter box; The filter box includes a box body, a filter element, and two sealing plates. The filter element is detachably disposed in the box body, and the two sealing plates are installed on the top two sides of the box body to seal the air inlet box and the air outlet pipe, respectively. The box body has an air inlet and an air outlet on each side, and the air inlet and air outlet are respectively located below the air inlet box and the air outlet pipe. A lifting cylinder, used to raise and lower the box body; A heating device is provided, comprising a heating jacket, an air inlet pipe, and a return pipe. The heating jacket is fitted over the reaction cylinder, and a partition is installed inside the heating jacket. The air inlet pipe includes an air supply pipe, a first branch pipe, and a second branch pipe. One end of the air supply pipe is connected to the first and second branch pipes via a tee pipe. Both the first branch pipe and the return pipe communicate with the heating jacket and are located on opposite sides of the partition. A valve is installed on the first branch pipe. The second branch pipe is connected to the air inlet box, and the end of the air outlet pipe away from the drying filter box is connected to the heating jacket.

6. The reaction processing apparatus according to claim 5, characterized in that, The air inlet is provided with an upper air inlet and a lower air inlet, and the upper air inlet and the lower air inlet are located above and below the filter element, respectively.

7. The reaction processing apparatus according to claim 5, characterized in that, The reaction cylinder includes a cylinder body and a cylinder cover. The cylinder cover is fitted onto the top of the cylinder body, and the heating sleeve is fitted onto the cylinder body. The reaction processing device also includes a lifting cylinder for lifting the cylinder cover.

8. The reaction processing apparatus according to claim 7, characterized in that, The stirring device includes a connecting plate, a motor, a stirring shaft, and stirring blades. The connecting plate connects the output end of the lifting cylinder and the cylinder cover. The motor is mounted on the connecting plate. One end of the stirring shaft is mounted on the output end of the motor, and the other end passes through the connecting plate and the cylinder cover in sequence before connecting to the stirring blades.

9. The reaction processing apparatus according to claim 8, characterized in that, The bottom end of the stirring shaft is provided with a square groove. The box is provided with a material turning assembly. The material turning assembly includes a rotating shaft, a square shaft, two connecting rods and multiple material turning rods. The rotating shaft is rotatably installed at the center of the box. The square shaft is installed at the top of the rotating shaft and located below the square groove. The two connecting rods are respectively installed on both sides of the rotating shaft. The multiple material turning rods are installed at intervals at the bottom of the connecting rods. The material turning rods at the bottom of the two connecting rods are staggered. When the valve is opened, the lifting cylinder raises the box body, so that the air inlet and the air outlet are connected to the air inlet box and the air outlet pipe respectively, and the square shaft is inserted into the square groove.

10. The reaction processing apparatus according to claim 9, characterized in that, The stirring device also includes a conical block, which is installed on the stirring shaft and located below the stirring blades. The conical block is suspended above the discharge port of the cylinder, and the diameter of the conical block is the same as the diameter of the discharge port.

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