Method for synergistically recovering lithium from waste aluminum electrolysis slag and lithium carbonate preparation equipment

Abstract

The application provides a method for cooperatively recovering lithium from waste aluminum electrolysis slag and lithium carbonate preparation equipment, and relates to the field of battery material preparation.The method for cooperatively recovering lithium from waste aluminum electrolysis slag comprises the following steps: S1, crushing and grinding the waste aluminum electrolysis slag to a particle size of less than 180 mu m, and drying the waste aluminum electrolysis slag for standby; S2, uniformly mixing the treated waste aluminum electrolysis slag with calcium sulfate according to a mass ratio of 1:0.9-1:1.3, placing the mixture in a calcination furnace, and calcining and treating the mixture under the condition of 850-950 DEG C, and obtaining a calcination product after cooling; and S3, adding deionized water to the calcination product according to a liquid-solid ratio of 3:1-5:1 to perform water immersion treatment, and performing solid-liquid separation after leaching is completed.The method for cooperatively recovering lithium from waste aluminum electrolysis slag provided by the application efficiently realizes the recycling of lithium resources in waste aluminum electrolysis slag, finally prepares high-purity battery-grade lithium carbonate products, and simultaneously considers the cooperative recycling of by-products such as fluorine and sodium, has high material recycling rate, is environment-friendly and low in energy consumption.

Description

Technical Field

[0001] This invention relates to the field of battery material preparation, and in particular to a method for co-recovering lithium from waste aluminum electrolytic slag and a lithium carbonate preparation apparatus. Background Technology

[0002] Waste aluminum electrolytic slag is a hazardous solid waste generated during the aluminum electrolysis production process. It contains large amounts of soluble fluorides, cyanides, and valuable metal elements such as lithium, sodium, and aluminum. Stockpiling or landfilling it can cause fluorides to leach into the soil and groundwater, resulting in serious environmental pollution and health threats.

[0003] Meanwhile, the lithium content in waste aluminum electrolytic slag can reach 1% to 2.7%, the sodium content exceeds 20%, and the fluorine content exceeds 35%, making it of significant resource recycling value.

[0004] Among existing lithium extraction methods, acid leaching results in high acid consumption, severe equipment corrosion, and the generation of harmful HF gas; alkaline leaching has low lithium extraction efficiency; the combined acid-alkali method is complex and difficult to industrialize; and while the roasting-leaching combined process improves the lithium extraction rate, it still suffers from problems such as high consumption of concentrated sulfuric acid, unresolved fluorine pollution, ineffective recovery of sodium resources, and high energy consumption for lithium enrichment. In particular, existing processes generally solidify fluorine in the form of CaF2 and store it as tailings, failing to achieve high-value recovery; sodium remains in the leachate mainly as low-value salt and is not effectively utilized.

[0005] Therefore, it is necessary to provide a method for co-recovering lithium from waste aluminum electrolytic slag and a lithium carbonate preparation device to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a method for co-recovering lithium from waste aluminum electrolytic slag, solving the problem of how to recover fluorine and sodium resources in the lithium extraction method from waste aluminum electrolytic slag.

[0007] To address the aforementioned technical problems, the present invention provides a method for co-recovering lithium from waste aluminum electrolytic slag, comprising the following steps:

[0008] S1. Crush and grind the waste aluminum electrolytic slag to a particle size of less than 180μm, and dry it for later use;

[0009] S2. The treated waste aluminum electrolytic slag and calcium sulfate are mixed evenly at a mass ratio of 1:0.9 to 1:1.3, placed in a roasting furnace, and roasted at 850 to 950°C. After cooling, the roasted product is obtained.

[0010] S3. Add deionized water to the roasted product at a liquid-solid ratio of 3:1 to 5:1 for water leaching treatment. After leaching, separate the solid and liquid to obtain leachate containing lithium and sodium and leachate residue containing calcium fluoride and alumina.

[0011] S4. Add sodium carbonate solution to lithium and sodium leaching solution, adjust the pH of the system to 9-11, filter after the reaction to obtain purified solution and calcium carbonate by-product.

[0012] S5. The purified liquid is extracted and separated using a three-stage countercurrent extraction process. The resulting loaded organic phase is back-extracted using a 1.0-2.0 mol / L sulfuric acid solution to obtain a high-concentration lithium-enriched solution and raffinate.

[0013] S6. The raffinate is concentrated by evaporation and cooled to crystallize, and sodium sulfate byproduct is precipitated.

[0014] S7, the leaching residue containing calcium fluoride and alumina is ground and flotated to obtain CaF2 concentrate and alumina-rich tailings;

[0015] S8. A Na2CO3 solution is prepared using the dissolving tank 4 of the lithium carbonate preparation equipment. Then, the lithium enrichment solution and the Na2CO3 solution are transported to the reaction cylinder 2 for reaction. After the reaction is completed, the lithium carbonate product for battery materials is obtained by filtration, washing and drying.

[0016] Preferably, in step S3, HBL121 extractant is used for three-stage countercurrent extraction; wherein the extraction conditions are: HBL121 volume concentration of 20% to 40%, pH value of 13 to 14, O / A ratio of 0.5:1 to 2:1, and mixing time of 1 to 5 minutes.

[0017] Preferably, the residual mother liquor from crystallization in step S6 is recycled to the water immersion process for reuse.

[0018] Preferably, in step S7, sodium oleate is used as the collector and sodium silicate as the inhibitor, and flotation is carried out under conditions of pH 7-8.

[0019] The present invention also provides a lithium carbonate preparation apparatus for use in step S8 of a method for co-recovering lithium from waste aluminum electrolytic slag;

[0020] Includes: support stations;

[0021] A reaction cylinder, which is mounted on the support platform;

[0022] A dissolving tank includes a tank body, a tank cover, a material holding cylinder, and a second stirring component. The tank cover is detachably installed on the top of the tank body, and the material holding cylinder is installed on the bottom of the tank cover. The bottom of the material holding cylinder is conical and has a discharge port. The tank cover has a feeding pipe corresponding to the position of the material holding cylinder.

[0023] The second stirring component includes a second stirring shaft, a second stirring blade, a spiral feeding component, and a driving component. The top end of the second stirring shaft passes through the discharge port and the tank cover in sequence and is rotatably connected to the tank cover. The spiral feeding component is installed on the second stirring shaft and is located inside the material container. The second stirring blade is installed at the bottom end of the second stirring shaft. The driving component is used to drive the second stirring shaft to rotate.

[0024] An infusion assembly for delivering the solution from the dissolving tank to the reaction vessel.

[0025] Preferably, the reaction cylinder includes a cylinder body, a cylinder cover, a heating sleeve, and a first stirring element. The cylinder body is mounted on the support, the cylinder cover is detachably mounted on the top of the cylinder body, the heating sleeve is fitted over the outside of the cylinder body, and the first stirring element is mounted on the cylinder cover for stirring and mixing the solution inside the cylinder body.

[0026] Preferably, it further includes a rotating device, a lifting cylinder, and an arc-tooth plate. The lifting cylinder is installed on the support and located between the reaction cylinder and the dissolving tank. The rotating device includes a mounting plate, a motor, a gear, and a square shaft. One end of the mounting plate is rotatably mounted on the output end of the lifting cylinder. The motor is mounted on the other end of the mounting plate. The gear is fixedly mounted on the output shaft of the motor. The square shaft is fixedly mounted on the bottom end of the output shaft of the motor. The mounting plate is detachably connected to the cylinder cover.

[0027] The two ends of the arc-tooth plate are respectively installed on the cylinder cover and the can cover, and suspended above the gear. The two ends of the arc-tooth plate are symmetrically arranged. The top end of the first stirring shaft in the first stirring component is provided with a first square groove, and the square shaft is inserted into the first square groove. The driving component is a second square groove, which is opened at the top end of the second stirring shaft.

[0028] Preferably, a limiting plate is rotatably mounted on both the top and bottom ends of the mounting plate, and the limiting plate is sleeved on the output end of the lifting cylinder. Multiple positioning holes are provided on both the mounting plate and the limiting plate along the circumference. Multiple positioning rods are installed on the support, and the top ends of the positioning rods penetrate the positioning holes.

[0029] When the lifting cylinder raises the mounting plate to make the toothed plate mesh with the arc toothed plate, the positioning hole separates from the positioning rod.

[0030] Preferably, the lower limiting plate is equipped with a positioning tube, which is sleeved on the positioning rod.

[0031] Preferably, the top of the cylinder cover is equipped with multiple positioning sleeves, and the positioning sleeves are horizontally threaded with positioning shafts. The bottom of the mounting plate is equipped with multiple limiting posts, and the limiting posts are horizontally provided with insertion holes.

[0032] Compared with related technologies, the method for co-recovering lithium from waste aluminum electrolytic slag and the lithium carbonate preparation equipment provided by the present invention have the following beneficial effects:

[0033] This invention provides a method for the co-recovery of lithium from waste aluminum electrolytic slag, which efficiently realizes the resource recovery of lithium resources in waste aluminum electrolytic slag and finally produces high-purity battery-grade lithium carbonate products. At the same time, it also takes into account the co-recovery and utilization of by-products such as fluorine and sodium. The material recycling rate is high, environmentally friendly and low energy consumption. Attached Figure Description

[0034] Figure 1 This is a flowchart illustrating the steps of a method for co-recovering lithium from waste aluminum electrolytic slag provided by the present invention.

[0035] Figure 2 A schematic diagram of the lithium carbonate preparation equipment provided by the present invention;

[0036] Figure 3 for Figure 2 A partial cross-sectional view of the lithium carbonate preparation equipment shown.

[0037] Figure 4 for Figure 2 A schematic diagram of the lithium carbonate preparation equipment from another perspective;

[0038] Figure 5 A top view of the lithium carbonate preparation apparatus provided by the present invention;

[0039] Figure 6 This is a schematic diagram of the meshing of a gear and an arc-tooth plate provided by the present invention;

[0040] Figure 7 This is a schematic diagram showing the alignment of the square shaft and the second square groove provided by the present invention;

[0041] Figure 8 This is a schematic diagram of the assembly of the square shaft and the second square groove provided by the present invention.

[0042] Numbering on the map:

[0043] 1. Support platform;

[0044] 2. Reaction cylinder; 21. Cylinder body; 22. Cylinder cover; 23. Heating jacket;

[0045] 221. Positioning sleeve; 222. Positioning shaft;

[0046] 3. First stirring component; 31. Stirring shaft one; 32. Stirring blade one; 311. First square groove;

[0047] 4. Dissolving tank; 41. Tank body; 42. Tank lid; 43. Feeding cylinder; 421. Support cylinder;

[0048] 5. Second mixing component; 51. Second mixing shaft; 52. Second mixing blade; 53. Spiral feeder; 511. Second square trough;

[0049] 6. Rotating device; 61. Mounting plate; 62. Motor; 63. Gear; 64. Square shaft; 601. Limiting plate; 602. Positioning tube; 603. Positioning hole; 611. Limiting post; 612. Insertion hole;

[0050] 7. Lifting cylinder; 71. Positioning rod;

[0051] 8. Infusion assembly; 81. Metering pump; 82. Inlet pipe; 83. Outlet pipe;

[0052] 9. Arcuate plate; 91. Connecting frame. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0054] This invention provides a method for co-recovering lithium from waste aluminum electrolytic slag and a lithium carbonate preparation device.

[0055] Please refer to the following: Figure 1 In one embodiment of the present invention, the method for co-recovering lithium from waste aluminum electrolytic slag includes the following steps:

[0056] S1. Crush and grind the waste aluminum electrolytic slag to a particle size of less than 180μm, and dry it for later use;

[0057] S2. The treated waste aluminum electrolytic slag and calcium sulfate are mixed evenly at a mass ratio of 1:0.9 to 1:1.3, placed in a roasting furnace, and roasted at 850 to 950°C. After cooling, the roasted product is obtained.

[0058] S3. Add deionized water to the roasted product at a liquid-solid ratio of 3:1 to 5:1 for water leaching treatment. After leaching, separate the solid and liquid to obtain leachate containing lithium and sodium and leachate residue containing calcium fluoride and alumina.

[0059] S4. Add sodium carbonate solution to lithium and sodium leaching solution, adjust the pH of the system to 9-11, filter after the reaction to obtain purified solution and calcium carbonate by-product.

[0060] S5. The purified liquid is extracted and separated using a three-stage countercurrent extraction process. The resulting loaded organic phase is back-extracted using a 1.0-2.0 mol / L sulfuric acid solution to obtain a high-concentration lithium-enriched solution and raffinate.

[0061] S6. The raffinate is concentrated by evaporation and cooled to crystallize, and sodium sulfate byproduct is precipitated.

[0062] S7, the leaching residue containing calcium fluoride and alumina is ground and flotated to obtain CaF2 concentrate and alumina-rich tailings;

[0063] S8. A Na2CO3 solution is prepared using the dissolving tank 4 of the lithium carbonate preparation equipment. Then, the lithium enrichment solution and the Na2CO3 solution are transported to the reaction cylinder 2 for reaction. After the reaction is completed, the lithium carbonate product for battery materials is obtained by filtration, washing and drying.

[0064] In this invention, CaF2 concentrate is washed and dried and used as a fluorochemical raw material, while alumina-rich tailings are returned to the aluminum electrolysis system as aluminum raw material.

[0065] The method for synergistically recovering lithium from waste aluminum electrolytic slag provided by this invention uses waste aluminum electrolytic slag as raw material, and is activated by high-temperature roasting with calcium sulfate. The valuable components of lithium and sodium are efficiently dissolved by water leaching. Through pH conditioning to remove impurities, selective extraction in an alkaline system and sulfuric acid back-extraction, the precise enrichment of lithium and separation of impurities are achieved.

[0066] Simultaneously, the leaching residue is ground and floated to recover calcium fluoride concentrate and aluminum-rich tailings. The extraction tailings are crystallized to obtain sodium sulfate by-product, and the crystallization mother liquor is recycled back to the water leaching process in a closed loop.

[0067] This method efficiently recovers lithium resources from waste aluminum electrolytic slag, ultimately producing high-purity battery-grade lithium carbonate. It also takes into account the synergistic recovery and utilization of by-products such as fluorine and sodium, resulting in high material recycling rate, environmental friendliness, and low energy consumption.

[0068] Preferably, in step S3, HBL121 extractant is used for three-stage countercurrent extraction; wherein the extraction conditions are: HBL121 volume concentration of 20% to 40%, pH value of 13 to 14, O / A ratio of 0.5:1 to 2:1, and mixing time of 1 to 5 minutes.

[0069] HBL121 is p-tert-octylphenyl phosphate.

[0070] Preferably, the residual mother liquor from crystallization in step S6 is recycled to the water immersion process for reuse.

[0071] Preferably, in step S7, sodium oleate is used as the collector and sodium silicate as the inhibitor, and flotation is carried out under conditions of pH 7-8.

[0072] As a specific embodiment of the present invention, it includes the following steps:

[0073] S1. Crush and grind the waste aluminum electrolytic slag to a particle size of less than 180 μm, and dry it for later use.

[0074] S2. Mix the obtained waste aluminum electrolytic slag with calcium sulfate at a mass ratio of 1:0.9 to 1:1.3, place it in a roasting furnace, and roast at 850 to 950°C for 60 to 120 minutes to convert lithium into Li2SO4, sodium into Na2SO4, fluorine into CaF2, and aluminum into stable Al2O3.

[0075] S3. The obtained roasted product is soaked in water for 10 to 30 minutes at a liquid-solid ratio of 3:1 to 5:1 and a temperature of 20 to 40°C. After filtration and separation, a leachate containing lithium and sodium and a leachate residue containing CaF2 and Al2O3 are obtained.

[0076] S4. The obtained lithium and sodium leaching solution is subjected to precipitation to remove calcium ions. Sodium carbonate is added to adjust the pH to 9-11 to remove calcium ions. After filtration, a purified solution and calcium carbonate by-product are obtained.

[0077] S5. The purified solution was subjected to three-stage countercurrent extraction using HBL121 extractant to selectively extract lithium. The extraction conditions were: HBL121 volume concentration 20% to 40%, pH 13 to 14, O / A ratio 0.5:1 to 2:1, and mixing time 1 to 5 minutes. After extraction, the lithium extraction rate reached over 99%, and sodium remained in the raffinate.

[0078] The obtained supported organic phase was back-extracted with 1.0–2.0 mol / L H2SO4 solution, with an O / A ratio of 4:1–8:1. After back-extraction, a lithium-enriched solution was obtained, and the lithium concentration increased from 1.24 g / L to over 15.56 g / L.

[0079] S6. The obtained raffinate is evaporated, concentrated, cooled and crystallized to obtain sodium sulfate by-product. The mother liquor is returned to the water leaching process for recycling.

[0080] S7. The obtained leaching residue containing CaF2 and Al2O3 is ground and floated using sodium oleate as a collector and sodium silicate as a depressant at a pH of 7-8 to obtain CaF2 concentrate and alumina-rich tailings. The CaF2 concentrate is washed and dried and used as a fluorochemical raw material, while the alumina-rich tailings are returned to the aluminum electrolysis system as aluminum raw material.

[0081] S8. Slowly add the obtained lithium enrichment solution to a 250 g / L Na2CO3 solution, react at 90-100℃ for 30-90 minutes, filter, wash, and dry to obtain battery-grade lithium carbonate product.

[0082] The present invention also provides a lithium carbonate preparation apparatus, which is used in step S8 of the method for co-recovering lithium from waste aluminum electrolytic slag, and can also be used in other lithium extraction processes, wherein the lithium-containing solution reacts with sodium carbonate.

[0083] Please see Figure 2 and Figure 3 A lithium carbonate preparation apparatus, comprising: a support 1;

[0084] The reaction cylinder 2 is mounted on the support 1;

[0085] Dissolving tank 4 includes tank body 41, tank cover 42, material container 43 and second stirring component 5. The tank cover 42 is detachably installed on the top of the tank body 41. The material container 43 is installed on the bottom of the tank cover 42. The bottom of the material container 43 is conical and has a discharge port. The tank cover 42 is provided with a feeding pipe corresponding to the position of the material container 43.

[0086] The second stirring component 5 includes a second stirring shaft 51, a second stirring blade 52, a spiral feeder 53, and a driving component. The top end of the second stirring shaft 51 passes through the discharge port and the tank cover 42 in sequence and is rotatably connected to the tank cover 42. The spiral feeder 53 is installed on the second stirring shaft 51 and is located inside the material container 43. The second stirring blade 52 is installed at the bottom end of the second stirring shaft 51. The driving component is used to drive the second stirring shaft 51 to rotate.

[0087] Infusion assembly 8 is used to deliver the solution in the dissolving tank 4 to the reaction cylinder 2.

[0088] The bottom end of the spiral feeder 53 extends into the discharge port.

[0089] First, a sodium carbonate solution is prepared using a dissolving tank 4. Deionized water is added to the dissolving tank 4. Sodium carbonate powder is then added to the container 43 through the feeding pipe. The second stirring element 5 is activated. The stirring shaft 51 simultaneously drives the stirring blade 52 and the spiral feeder 53 to rotate. The spiral feeder 53 slowly and evenly carries the sodium carbonate powder downwards into the deionized water. At the same time, the stirring blade 52 stirs the deionized water, so that the sodium carbonate powder and deionized water are evenly mixed to form a sodium carbonate solution.

[0090] After the sodium carbonate solution is mixed, it is transported to the reaction cylinder 2 through the infusion assembly 8, and then lithium enrichment solution is added to react and generate lithium carbonate precipitate.

[0091] This lithium carbonate preparation equipment integrates a dissolving tank 4 for preparing sodium carbonate solution. After preparation, the solution is added to the reaction cylinder 2 and subsequently reacts with the lithium enrichment solution to form lithium carbonate precipitate. It is not necessary to prepare sodium carbonate solution separately and then transfer it to the reaction cylinder 2. Furthermore, by setting up a material container 43, and in conjunction with a spiral feeder 53 on the stirring shaft 2 51, sodium carbonate powder can be slowly and evenly added to deionized water. After stirring and mixing, a sodium carbonate solution is formed, which prevents the sodium carbonate powder from clumping and dissolving unevenly. At the same time, it avoids excessively high local alkalinity and a sudden rise in system temperature, ensuring that the concentration of the prepared sodium carbonate solution is uniform and stable.

[0092] In this embodiment, a liquid addition pipe is also provided on the tank cover 42 for adding deionized water into the tank body 41. The liquid addition pipe is staggered from the material container 43. Of course, deionized water can also be added into the tank body 41 by opening the tank cover 42.

[0093] Please see Figure 2 and Figure 3 In this embodiment, the reaction cylinder 2 includes a cylinder body 21, a cylinder cover 22, a heating sleeve 23, and a first stirring element 3. The cylinder body 21 is installed on the support 1, the cylinder cover 22 is detachably installed on the top of the cylinder body 21, the heating sleeve 23 is sleeved on the outside of the cylinder body 21, and the first stirring element 3 is installed on the cylinder cover 22 for stirring and mixing the solution inside the cylinder body 21.

[0094] The cylinder cover 22 is equipped with a liquid addition pipe for adding lithium enrichment solution into the cylinder 21. Alternatively, the solution can be added by opening the cylinder cover 22. Both the cylinder 21 and the tank 41 have drain pipes at their bottom ends, and the drain pipes are equipped with valves.

[0095] The infusion assembly 8 adds the prepared sodium carbonate solution into the reaction cylinder 2, and then adds lithium enrichment solution. The first stirrer 3 drives the stirring of the solution to make it react fully, and then discharges it to the next process through the drain pipe of the cylinder 21.

[0096] In this embodiment, the tank body 41 is preferably mounted on the support platform 1 by means of support legs;

[0097] Multiple positioning ears are provided on the top periphery of the cylinder 21, and assembly holes are opened on the positioning ears. An assembly shaft is installed on the periphery of the cylinder cover 22 through a connecting block. When the cylinder cover 22 is placed on the cylinder 21, the assembly shaft passes through the assembly holes, improving the stability of the installation. Furthermore, a threaded surface can be provided on the assembly shaft, which, together with the nut thread connection, further improves the stability of the connection. The assembly method of the tank body 41 and the tank cover 42 is the same as the assembly method of the cylinder body 21 and the cylinder cover 22.

[0098] Temperature detectors and pH detectors are installed on both the cylinder 21 and the tank 41;

[0099] The heating jacket 23 is equipped with an inlet pipe and an outlet pipe. The inlet pipe is used to input heating liquid (or gas) into the heating jacket 23 to heat the cylinder 21 to the reaction temperature. After heat exchange, the heating liquid is discharged to the heating equipment through the outlet pipe. Subsequently, it is pumped back into the heating jacket 23 through the inlet pipe via a pipeline and a water pump. The heating jacket 23 is equipped with a partition, and the inlet pipe and outlet pipe are located on both sides of the partition, and at the bottom and top of the heating jacket 23 respectively (not shown in the figure), so that the liquid can circle the heating jacket 23 and achieve uniform heating.

[0100] Please see Figure 4 In this embodiment, the infusion assembly 8 includes a metering pump 81, an inlet pipe 82, and an outlet pipe 83. The inlet pipe 82 connects the inlet end of the metering pump 81 to the drain pipe of the tank 41, and the outlet pipe 83 connects the outlet end of the metering pump 81 to the cylinder 21. The metering pump 81 is mounted on the support 1.

[0101] In this embodiment, the first stirring component 3 includes a stirring shaft 31, a stirring blade 32, and a first square groove 311. The stirring shaft 31 is rotatably mounted on the cylinder cover 22, and the stirring blade 32 is mounted on the stirring shaft 31 and located inside the cylinder 21.

[0102] Please see Figure 2 and Figure 3 As an optional embodiment, the lithium carbonate preparation equipment further includes a rotating device 6, a lifting cylinder 7, and an arc-tooth plate 9. The lifting cylinder 7 is installed on the support 1 and located between the reaction cylinder 2 and the dissolving tank 4. The rotating device 6 includes a mounting plate 61, a motor 62, a gear 63, and a square shaft 64. One end of the mounting plate 61 is rotatably mounted on the output end of the lifting cylinder 7. The motor 62 is mounted on the other end of the mounting plate 61. The gear 63 is fixedly mounted on the output shaft of the motor 62. The square shaft 64 is fixedly mounted on the bottom end of the output shaft of the motor 62. The mounting plate 61 is detachably connected to the cylinder cover 22.

[0103] The two ends of the arc-tooth plate 9 are respectively installed on the cylinder cover 22 and the tank cover 42, and suspended above the gear 63. The two ends of the arc-tooth plate 9 are symmetrically arranged. The top end of the stirring shaft 31 in the first stirring component 3 is provided with a first square groove 311. The square shaft 64 is inserted into the first square groove 311. The driving component is a second square groove 511, which is opened at the top end of the stirring shaft 51.

[0104] When preparing sodium carbonate solution, the lifting cylinder 7 raises the mounting plate 61, which in turn drives the motor 62 to rise, causing the square shaft 64 to separate from the first square groove 311. Simultaneously, the gear 63 meshes with the arc-tooth plate 9. Figure 6 ;

[0105] At this time, motor 62 drives gear 63 to rotate, interacting with the arc-tooth plate 9. Gear 63 drives motor 62 and mounting plate 61 to rotate 90 degrees along the arc-tooth plate 9, after which square shaft 64 is positioned above the second square groove 511. Figure 7 ;

[0106] The lifting cylinder 7 lowers the mounting plate 61, allowing the square shaft 64 to be inserted into the second square groove 511. Figure 8 Subsequently, the motor 62 operates, and the square shaft 64, in conjunction with the second square groove 511, drives the stirring shaft 51 to rotate, thereby driving the spiral feeder 53 and the stirring blade 52 to rotate to achieve the feeding and mixing of sodium carbonate.

[0107] The same operation is performed when the sodium carbonate solution reacts with the lithium enrichment solution. In this case, the motor 62 rotates in the opposite direction, the gear 63 interacts with the arc tooth plate 9, so that the square shaft 64 is aligned with the first square groove 311 again, and the lifting cylinder 7 lowers the mounting plate 61 so that the square shaft 64 is inserted into the first square groove 311 again.

[0108] Thus, the rotating device 6 sequentially has the functions of driving the first stirring element 3 to rotate, adjusting the position of the rotating device 6 by interacting with the arc-tooth plate 9, and driving the second stirring element 5 to achieve uniform feeding and mixing of sodium carbonate, thus simplifying the equipment structure.

[0109] Furthermore, in the usage state, the mounting plate 61 and the cylinder cover 22 are in the unlocked state;

[0110] When it is necessary to inspect and maintain the first mixing component 3 and the second mixing component 5, install the mounting plate 61 and the cylinder cover 22.

[0111] Thus, the lifting cylinder 7 raises the mounting plate 61, which, together with the arc tooth plate 9, can simultaneously drive the cylinder cover 22 and the tank cover 42 to move upward, thereby driving the first stirring component 3 and the second stirring component 5 to move upward and remove the cylinder 21 and the tank 41, thus facilitating the cleaning, inspection, and maintenance of the first stirring component 3 and the second stirring component 5.

[0112] The material container 43 is preferably detachably mounted on the tank cover 42, and the material container 43 can be removed later to facilitate the inspection and maintenance of the second stirring component 5.

[0113] When the motor 62 drives the first stirring component 3 and the second stirring component 5 to work, it rotates an integer number of revolutions each time, so that the gear 63 can be aligned with the arc tooth plate 9 again, which facilitates subsequent assembly.

[0114] The two ends of the arc-tooth plate 9 are fixedly installed on the cylinder cover 22 and the can cover 42 by connecting brackets 91.

[0115] In another optional embodiment, two motors 62 can be provided to drive the first stirring shaft 31 and the second stirring shaft 51 to rotate respectively.

[0116] Please see Figure 2 and Figure 3 In a preferred embodiment, the top and bottom ends of the mounting plate 61 are rotatably mounted with a limiting plate 601, and the limiting plate 601 is sleeved on the output end of the lifting cylinder 7. The mounting plate 61 and the limiting plate 601 are provided with a plurality of positioning holes 603 along the circumferential direction. A plurality of positioning rods 71 ​​are installed on the support 1, and the top end of the positioning rod 71 passes through the positioning hole 603.

[0117] When the lifting cylinder 7 raises the mounting plate 61 to make the gear 63 mesh with the arc tooth plate 9, the positioning hole 603 separates from the positioning rod 71.

[0118] By setting a limiting plate 601 to further limit and protect the mounting plate 61, the stability of the mounting plate 61 during rotation is improved. At the same time, a positioning rod 71 is set to limit the mounting plate 61 in the rotation direction, ensuring the stability of the rotating device 6 when driving the first stirring component 3 or the second stirring component 5 to rotate. Four positioning holes 603 are evenly opened in the circumferential direction, so that after the mounting plate 61 rotates 90 degrees, the positioning rod 71 can be aligned with the positioning hole 603 again, and the positioning holes 603 on the mounting plate 61 and the limiting plate 601 are aligned.

[0119] Please see Figure 3 As an optional embodiment, the lower limiting plate 601 is equipped with a positioning tube 602, which is sleeved on the positioning rod 71.

[0120] By setting the positioning tube 602, when the lifting cylinder 7 lifts the mounting plate 61, it causes the cylinder cover 22 and the tank cover 42 to move upward, so that the first stirring component 3 and the second stirring component 5 move out of the cylinder 21 and the tank 41 respectively. The positioning tube 602, together with the positioning rod 71, limits the mounting plate 61 in the horizontal direction, so that it moves more stably in the vertical direction.

[0121] By setting the positioning tube 602 on the lower limiting plate 601, and the limiting plate 601 being rotatably connected to the mounting plate 61, the rotation of the mounting plate 61 is not affected after the positioning rod 71 is separated from the positioning hole 603.

[0122] Please see Figure 2 and Figure 3 As a preferred embodiment, the top of the cylinder cover 22 is equipped with a plurality of positioning sleeves 221, and the positioning sleeves 221 are horizontally threaded with positioning shafts 222. The bottom of the mounting plate 61 is equipped with a plurality of limiting posts 611, and the limiting posts 611 are horizontally provided with insertion holes 612.

[0123] When the square shaft 64 is inserted into the first square groove 311, the limiting post 611 is inserted into the corresponding positioning sleeve 221. The positioning sleeve 221 supports the mounting plate 61, thereby further limiting the mounting plate 61 and improving the stability of the rotating device 6.

[0124] When it is necessary to fix the mounting plate 61 to the cylinder cover 22, turn the positioning shaft 222 to insert it into the insertion hole 612 of the limiting post 611 to connect the mounting plate 61 to the cylinder cover 22. The operation is simple.

[0125] A nut is fixed on one side of the positioning sleeve 221, and one end of the positioning shaft 222 passes through the nut and one side of the positioning sleeve 221 and is threadedly connected to the nut.

[0126] Among them, a support cylinder 421 is provided on the can cover 42. When the square shaft 64 is assembled with the second square groove 511, the limiting post 611 is inserted into the support cylinder 421, and the support cylinder 421 assists in supporting the mounting plate 61.

[0127] The width of the mounting plate 61 is wider than the diameter of the top feeding pipe of the can cover 42, and there are two support cylinders 421 located on both sides of the feeding pipe.

[0128] The working principle of the lithium carbonate preparation equipment provided by this invention is as follows:

[0129] First, a sodium carbonate solution is prepared using a dissolving tank 4. Deionized water is added to the dissolving tank 4. Sodium carbonate powder is then added to the container 43 through the feeding pipe. The second stirring element 5 is activated. The stirring shaft 51 simultaneously drives the stirring blade 52 and the spiral feeder 53 to rotate. The spiral feeder 53 slowly and evenly carries the sodium carbonate powder downwards into the deionized water. At the same time, the stirring blade 52 stirs the deionized water, so that the sodium carbonate powder and deionized water are evenly mixed to form a sodium carbonate solution.

[0130] After the sodium carbonate solution is mixed, it is transported to the reaction cylinder 2 through the infusion assembly 8, and then lithium enrichment solution is added to react and generate lithium carbonate precipitate.

[0131] This lithium carbonate preparation equipment integrates a dissolving tank 4 for preparing sodium carbonate solution. After preparation, the solution is added to the reaction cylinder 2 and subsequently reacts with the lithium enrichment solution to generate lithium carbonate precipitate. It is not necessary to prepare sodium carbonate solution separately and then transfer it to the reaction cylinder 2. Furthermore, by setting up a material container 43, and in conjunction with a spiral feeder 53 on the stirring shaft 2 51, sodium carbonate powder can be slowly and evenly added to deionized water. After stirring and mixing, a sodium carbonate solution is formed, which prevents the sodium carbonate powder from clumping and dissolving unevenly. At the same time, it avoids excessively high local alkalinity and a sudden rise in system temperature, ensuring that the concentration of the prepared sodium carbonate solution is uniform and stable.

[0132] When preparing sodium carbonate solution, the lifting cylinder 7 raises the mounting plate 61, which in turn drives the motor 62 to rise, causing the square shaft 64 to separate from the first square groove 311. Simultaneously, the gear 63 meshes with the arc-tooth plate 9. Figure 6 ;

[0133] At this time, motor 62 drives gear 63 to rotate, interacting with the arc-tooth plate 9. Gear 63 drives motor 62 and mounting plate 61 to rotate 90 degrees along the arc-tooth plate 9, after which square shaft 64 is positioned above the second square groove 511. Figure 7 ;

[0134] The lifting cylinder 7 lowers the mounting plate 61, allowing the square shaft 64 to be inserted into the second square groove 511. Figure 8 Subsequently, the motor 62 operates, and the square shaft 64, in conjunction with the second square groove 511, drives the stirring shaft 51 to rotate, thereby driving the spiral feeder 53 and the stirring blade 52 to rotate to achieve the feeding and mixing of sodium carbonate.

[0135] The same operation is performed when the sodium carbonate solution reacts with the lithium enrichment solution. In this case, the motor 62 rotates in the opposite direction, the gear 63 interacts with the arc tooth plate 9, so that the square shaft 64 is aligned with the first square groove 311 again, and the lifting cylinder 7 lowers the mounting plate 61 so that the square shaft 64 is inserted into the first square groove 311 again.

[0136] Thus, the rotating device 6 sequentially has the functions of driving the first stirring element 3 to rotate, adjusting the position of the rotating device 6 by interacting with the arc-tooth plate 9, and driving the second stirring element 5 to achieve uniform feeding and mixing of sodium carbonate, thus simplifying the equipment structure.

[0137] 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. A method for co-recovering lithium from waste aluminum electrolytic slag, characterized in that, Includes the following steps: S1. Crush and grind the waste aluminum electrolytic slag to a particle size of less than 180μm, and dry it for later use; S2. The treated waste aluminum electrolytic slag and calcium sulfate are mixed evenly at a mass ratio of 1:0.9 to 1:1.3, placed in a roasting furnace, and roasted at 850 to 950°C. After cooling, the roasted product is obtained. S3. Add deionized water to the roasted product at a liquid-solid ratio of 3:1 to 5:1 for water leaching treatment. After leaching, separate the solid and liquid to obtain leachate containing lithium and sodium and leachate residue containing calcium fluoride and alumina. S4. Add sodium carbonate solution to lithium and sodium leaching solution, adjust the pH of the system to 9-11, filter after the reaction to obtain purified solution and calcium carbonate by-product. S5. The purified liquid is extracted and separated using a three-stage countercurrent extraction process. The resulting loaded organic phase is back-extracted using a 1.0-2.0 mol / L sulfuric acid solution to obtain a high-concentration lithium-enriched solution and raffinate. S6. The raffinate is concentrated by evaporation and cooled to crystallize, and sodium sulfate byproduct is precipitated. S7, the leaching residue containing calcium fluoride and alumina is ground and flotated to obtain CaF2 concentrate and alumina-rich tailings; S8. A Na2CO3 solution is prepared using the dissolving tank 4 of the lithium carbonate preparation equipment. Then, the lithium enrichment solution and the Na2CO3 solution are transported to the reaction cylinder 2 for reaction. After the reaction is completed, the lithium carbonate product for battery materials is obtained by filtration, washing and drying.

2. The method for co-recovering lithium from waste aluminum electrolytic slag according to claim 1, characterized in that, In step S3, HBL121 extractant is used for three-stage countercurrent extraction; the extraction conditions are: HBL121 volume concentration of 20% to 40%, pH value of 13 to 14, O / A ratio of 0.5:1 to 2:1, and mixing time of 1 to 5 minutes.

3. The method for co-recovering lithium from waste aluminum electrolytic slag according to claim 1, characterized in that, The residual mother liquor from crystallization in step S6 is recycled to the water immersion process for reuse.

4. The method for co-recovering lithium from waste aluminum electrolytic slag according to claim 1, characterized in that, In S7, sodium oleate is used as the collector and sodium silicate as the inhibitor, and flotation is carried out under conditions of pH 7-8.

5. A lithium carbonate preparation apparatus, characterized in that, In step S8 of the method for co-recovering lithium from waste aluminum electrolytic slag as described in any one of claims 1-4; Includes: support stations; A reaction cylinder, which is mounted on the support platform; A dissolving tank includes a tank body, a tank cover, a material holding cylinder, and a second stirring component. The tank cover is detachably installed on the top of the tank body, and the material holding cylinder is installed on the bottom of the tank cover. The bottom of the material holding cylinder is conical and has a discharge port. The tank cover has a feeding pipe corresponding to the position of the material holding cylinder. The second stirring component includes a second stirring shaft, a second stirring blade, a spiral feeding component, and a driving component. The top end of the second stirring shaft passes through the discharge port and the tank cover in sequence and is rotatably connected to the tank cover. The spiral feeding component is installed on the second stirring shaft and is located inside the material container. The second stirring blade is installed at the bottom end of the second stirring shaft. The driving component is used to drive the second stirring shaft to rotate. An infusion assembly for delivering the solution from the dissolving tank to the reaction vessel.

6. The lithium carbonate preparation equipment according to claim 5, characterized in that, The reaction cylinder includes a cylinder body, a cylinder cover, a heating sleeve, and a first stirring element. The cylinder body is mounted on the support platform, the cylinder cover is detachably mounted on the top of the cylinder body, the heating sleeve is fitted over the outside of the cylinder body, and the first stirring element is mounted on the cylinder cover for stirring and mixing the solution inside the cylinder body.

7. The lithium carbonate preparation equipment according to claim 6, characterized in that, It also includes a rotating device, a lifting cylinder, and an arc-tooth plate. The lifting cylinder is installed on the support and located between the reaction cylinder and the dissolving tank. The rotating device includes a mounting plate, a motor, a gear, and a square shaft. One end of the mounting plate is rotatably mounted on the output end of the lifting cylinder. The motor is mounted on the other end of the mounting plate. The gear is fixedly mounted on the output shaft of the motor. The square shaft is fixedly mounted on the bottom end of the output shaft of the motor. The mounting plate is detachably connected to the cylinder cover. The two ends of the arc-tooth plate are respectively installed on the cylinder cover and the can cover, and suspended above the gear. The two ends of the arc-tooth plate are symmetrically arranged. The top end of the first stirring shaft in the first stirring component is provided with a first square groove, and the square shaft is inserted into the first square groove. The driving component is a second square groove, which is opened at the top end of the second stirring shaft.

8. The lithium carbonate preparation equipment according to claim 7, characterized in that, The top and bottom ends of the mounting plate are rotatably mounted with limit plates, and the limit plates are sleeved on the output end of the lifting cylinder. Both the mounting plate and the limit plates are provided with multiple positioning holes along the circumference. Multiple positioning rods are installed on the support, and the top ends of the positioning rods pass through the positioning holes. When the lifting cylinder raises the mounting plate to make the toothed plate mesh with the arc toothed plate, the positioning hole separates from the positioning rod.

9. The lithium carbonate preparation equipment according to claim 8, characterized in that, The lower limiting plate is equipped with a positioning tube, which is sleeved on the positioning rod.

10. The lithium carbonate preparation apparatus according to claim 7, characterized in that, The top of the cylinder cover is equipped with multiple positioning sleeves, and the positioning sleeves are horizontally threaded with positioning shafts. The bottom of the mounting plate is equipped with multiple limiting posts, and the limiting posts are horizontally provided with insertion holes.

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