Method for preparing lithium carbonate from aluminum electrolyte waste residues

Abstract

The invention discloses a method for preparing lithium carbonate from aluminum electrolyte waste residues, which comprises the following steps: adding an organic solvent into a leachate obtained by roasting the aluminum electrolyte waste residues to realize supersaturated precipitation of sodium sulfate and retention of lithium sulfate, and pre-separating impurity sodium ions; then adding a calixarene chelating agent to be complexed with sodium ions, and removing the sodium ions; then a nonionic surfactant is introduced to regulate and control the solvent microenvironment, the polarity, solvation ability and surface tension of the solution are changed, effective contact between the calixarene chelating agent and sodium ions is promoted, and the chelating efficiency is improved; finally, the high-purity lithium carbonate for battery manufacturing is prepared through a carbonization and crystallization step. The synergistic application of calixarene and the surfactant is used for extracting lithium from the aluminum electrolyte waste residues for the first time, the problems of sodium-lithium separation and low recovery rate of a low-concentration lithium ion solution in an aqueous solution system are effectively solved, and the method has the advantages of being environmentally friendly, efficient, high in product purity and high in lithium recovery rate.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial water treatment, and particularly relates to a method for preparing lithium carbonate from aluminum electrolyte waste residue. Background Art

[0002] The aluminum electrolyte slag contains recoverable lithium resources. Through effective extraction and recovery processes such as roasting, leaching, and carbonization crystallization, the effective utilization of limited lithium resources can be achieved, which helps to reduce the dependence on limited lithium ore resources, provides a sustainable raw material source for battery manufacturing, and reduces the environmental pollution risk of lithium resources. This technology also reflects the important role of chemical engineering in promoting the sustainable development of the new energy industry under the background of limited resources and environmental protection.

[0003] The preparation quality of battery-grade lithium carbonate is directly related to the performance of the battery, including improving the battery energy density, enhancing the cycle life, and ensuring safety. However, after the treatment of the aluminum electrolyte slag leaching solution, the solution consists of mixed basic sulfates, and the main valuable metal elements therein are lithium ions and sodium ions. The lithium ion content is 0.4 - 0.75 mol / L, and the sodium ion content is as high as 0.8 - 1.2 mol / L. The lithium ion content is too low, and the supersaturation is too low, resulting in the inability to obtain lithium carbonate precipitation by the carbonization method in aqueous solution; directly concentrating the reaction solution will cause the concentration of impurity sodium ions to be too high. The high concentration of sodium ions will affect the purity of battery-grade lithium carbonate and reduce its performance in lithium-ion batteries. Low-purity lithium carbonate may lead to a decrease in the energy density of the battery and a shortening of the cycle life, thereby limiting the effectiveness of the battery in new energy applications.

[0004] Directly separating and extracting the original solution with a high sodium-lithium ratio often has problems such as poor separation efficiency, still containing a small amount of impurity ions after separation, and poor separation efficiency, etc., and further impurity removal is required to ensure the high purity of lithium carbonate precipitation. In addition, sodium ions and lithium ions are similar in chemical properties, and improving the selectivity of lithium ions in the aluminum electrolyte slag leaching solution has become a key challenge for technical improvement. Further research and improvement of the extraction process are needed to reduce the interference of sodium ions on lithium. The aluminum electrolyte slag leaching solution with a high sodium content needs to be environmentally treated to reduce the adverse impact on the environment. Developing clean and efficient treatment methods is an urgent problem to be solved in current research to ensure the sustainability of the whole process. Summary of the Invention

[0005] The object of the present invention is to solve the problems existing in the prior art, such as the low lithium-sodium ratio in the leaching solution of aluminum electrolyte slag, the low direct separation and purification efficiency, the eutectic of lithium in sodium sulfate crystals resulting in poor lithium-sodium separation effect, and the decrease in the purity of lithium carbonate precipitate. A method for preparing lithium carbonate from aluminum electrolyte waste residue is provided. By using a chelating agent and a surfactant with high selectivity for impurity sodium ions, the impurity ions are effectively separated, and the extremely low solubility of lithium carbonate in organic solvents is utilized to achieve the preparation of lithium carbonate in a low-concentration lithium solution, obtaining lithium carbonate with both high recovery rate and purity.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for preparing lithium carbonate from aluminum electrolyte waste residue, comprising the following steps:

[0007] S1. Add an organic solvent to the leaching solution obtained after roasting the aluminum electrolyte waste residue. The volume ratio of the organic solvent to the leaching solution is 1:2 to 3:1. Stir at a constant temperature of 25 °C for 5 to 10 minutes, and the stirring speed is 300 - 600 r / min; after centrifuging the stirred suspension, obtain supernatant 1 and sodium sulfate precipitate;

[0008] S2. Add 0.1 - 1.0 wt% of calixarene chelating agent and 0.2 - 0.5 wt% of surfactant to supernatant 1 obtained in S1. The reaction temperature is 25 °C to 60 °C. After stirring and reacting for 10 to 20 minutes, perform solid-liquid separation to obtain a precipitate and supernatant 2;

[0009] S3. Add a carbonate solution with a concentration of 0.06 - 0.3 mol / L to supernatant 2 obtained in S2. The volume ratio of the carbonate solution to supernatant 2 is 1:1.5 to 1:3. Stir at a constant temperature for 10 minutes for carbonization crystallization reaction. After centrifuging, obtain lithium carbonate precipitate and supernatant 3;

[0010] S4. Wash the lithium carbonate precipitate obtained in S3 with hot water and dry it to obtain a lithium carbonate product.

[0011] Preferably, the lithium ion content in the leaching solution obtained after roasting the aluminum electrolyte waste residue is 0.4 - 0.75 mol / L, and the sodium ion content is 0.8 - 1.2 mol / L.

[0012] Preferably, the surfactant is Triton X-100 or Tween 20.

[0013] Preferably, the carbonate is sodium carbonate or potassium carbonate.

[0014] Further preferably, pass supernatant 3 obtained in S3 through an evaporation-condensation system. The distillation temperature is 56 - 80 °C, and the distillation pressure is normal atmospheric pressure to obtain an organic solvent and a sodium sulfate solution.

[0015] More preferably, the organic solvent is one of methanol, ethanol and acetone or a mixture of two of them.

[0016] More preferably, in S4, the lithium carbonate precipitate is washed with hot water at 60-80°C, the washing method is two leaching washes and one slurry wash, the solid-liquid ratio during washing is 1:5-1:10, and it is filtered while hot at a filtration temperature of 70-90°C, and the lithium carbonate product is obtained after drying.

[0017] The present invention adds an organic solvent to the aluminum electrolyte slag leachate, obtains a supernatant with a reduced sodium-lithium ratio after solid-liquid separation, and then uses a combination of calixarene and a nonionic surfactant (Triton X-100 or Tween 20) to promote and stabilize the chelation process, and finally adds carbonate for carbonization and crystallization to obtain lithium carbonate precipitation, and the separated organic solvent can be recycled. The specific principle is as follows:

[0018] When lithium carbonate is dissolved in water, the highly polar water molecules can effectively coordinate with the ions of lithium carbonate through hydrogen bonds to form stable hydrated ions dissolved in water. However, the addition of organic solvents reduces the overall polarity of the solvent, causes competition between solvent molecules, and weakens the hydration between lithium carbonate ions and water molecules. In addition, the introduction of organic solvents reduces the dielectric constant of the solution, reduces the electrostatic repulsion between ions in the solution, makes it easier for lithium ions to interact with carbonate ions at close range, and contributes to the formation and precipitation of lithium carbonate crystals. The introduction of organic solvents usually increases the total entropy of the system because the difference in interaction between solvent molecules leads to more disordered states. This increase in entropy and the change in solvation energy promote the formation of lithium carbonate crystals, making lithium carbonate more inclined to precipitate in a mixed solvent rather than remaining in a stable dissolved state in the solution. In short, the addition of organic solvents directly affects the solubility and stability of lithium carbonate by changing the solvent polarity and solvation effect, thereby promoting the precipitation of lithium carbonate crystals.

[0019] The chelation reaction can be used to remove the impurity sodium ions in a targeted manner. In the process, the stability of the complex is affected by the strength of the coordination bond between ions and the polarity of the solvent. The diameter of the sodium ion hydrate (approx. ) can provide a suitable spatial size to match the sodium ion, so that the sodium ion can be stably located at the center of the calixarene molecule, which can effectively fix the sodium ion in space, reduce the freedom of movement of the sodium ion, and enhance the stability of the complex.

[0020] Calixarenes are amphiphilic compounds, which are cyclic molecules formed by benzene rings connected through methylene bridges. They have a hydrophobic upper rim and a hydrophilic lower rim, and have the ability to chelate sodium ions in both aqueous and organic phases. The chelation of sodium ions increases the overall polarity and hydrophilicity of the complex, enabling it to interact more effectively with water molecules through electrostatic interactions and hydrogen bonds. This enhanced hydrophilicity promotes the dissolution and dispersion of the complex in the solvent, but there is instability. The solvent environment suitable for the chelation of calixarenes with sodium ions is usually one with relatively low polarity and weak interaction ability with metal ions, because the solvation effect of polar solvents may compete with sodium ions, thus reducing their effective contact with sodium ions. Adding nonionic surfactants such as Triton X-100 or Tween 20 can promote the chelation reaction by changing the polarity, solvation ability and surface tension of the solution. Triton X-100 provides a relatively nonpolar microenvironment when forming micelles through its amphiphilic structure, reducing the competitive interaction between water molecules and sodium ions, lowering the surface tension, and being beneficial to improving the chelation efficiency. Tween 20 increases the solubility of hydrophilic chelating agents such as calixarenes through its strong hydrophilicity, provides more chelation opportunities by reducing the surface tension, and forms a "protective layer" to reduce the direct contact between polar solvents and sodium ions, effectively reducing the interference of the solvation effect on the chelation and improving the chelation efficiency.

[0021] Advantages of the present invention:

[0022] 1. The present invention utilizes the extremely low solubility of lithium carbonate in organic solutions to achieve efficient and controllable precipitation of high-purity lithium carbonate. By taking advantage of the solubility difference between lithium ions and sodium ions in organic solvents, the sodium-lithium ratio in the solution is greatly reduced, the difficulty of subsequent separation of lithium ions is reduced, and further, the high selectivity of the chelating agent is utilized to ensure the separation of lithium and sodium ions, obtaining high-purity lithium carbonate precipitate.

[0023] 2. The present invention uses a high-sodium and low-lithium sulfate feed solution (lithium ion content is 0.4 - 0.75 mol / L, sodium ion content is 0.65 - 1.2 mol / L) as the raw material, and successfully realizes the precipitation of lithium carbonate in organic solvents (such as methanol, ethanol, acetone), improving the recovery rate of the low-lithium solution, with the recovery rate above 80%; and this organic solvent can be recycled through an appropriate recovery system (evaporation-condensation system), realizing the sustainable use of the organic solvent, reducing the demand for solvents in the experimental process, reducing production costs and environmental pollution, which conforms to the concept of green chemistry.

[0024] 3. The present invention recovers sodium sulfate from the leaching solution obtained after roasting aluminum electrolyte waste residue, reducing the generation of waste and further reducing environmental pollution.

[0025] 4. The method steps of the present invention are simple, easy to operate, have low requirements for equipment and environment, and are suitable for large-scale industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a process flow chart of the method for preparing lithium carbonate from aluminum electrolyte waste residue of the present invention;

[0027] Figure 2 are the characteristic diffraction peaks and standard spectra of the lithium carbonate products prepared in Examples 1-5 and Comparative Example 1;

[0028] Figure 3 are the purities of the lithium carbonate products prepared in Examples 1-5 and Comparative Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0030] Example 1

[0031] Step 1: The leaching solution of aluminum electrolyte slag is treated to obtain a mixed alkali metal sulfate solution (lithium ion content is 0.6 mol / L, sodium ion content is 1 mol / L). At 25 °C, methanol is added with a volume ratio of 1:2 to the mixed sulfate solution. After salting out, sodium sulfate precipitate is precipitated and sodium sulfate crystals are obtained after drying.

[0032] Step 2: Calixarene chelating agent (0.5 wt%) and TritonX-100 (0.2 wt%) are added to the supernatant 1 after centrifugation. Stir at a constant temperature of 40 °C for 10 min, and then centrifugally separate to obtain supernatant 2 and precipitate.

[0033] Step 3: Add 0.2 mol / L sodium carbonate solution to the supernatant 2 obtained in Step 2 for carbonization crystallization reaction. The volume ratio of the sodium carbonate solution to the supernatant 2 is 1.2:1. After reacting for 18 minutes, centrifugally separate to obtain lithium carbonate precipitate and supernatant 3.

[0034] Step 4: The supernatant 3 obtained in Step 3 is passed through an evaporation-condensation system to recover methanol. The evaporation temperature is 65 °C and the distillation pressure is normal atmospheric pressure to obtain methanol and sodium sulfate solution. The recovered methanol can be recycled and added to the mixed sulfate solution in Step 1.

[0035] Step 5: The lithium carbonate precipitate is washed with hot water at 60-80 °C. The washing method is two times of shower washing plus one time of slurry washing. The solid-liquid ratio during washing is 1:5. Filter while it is hot, the filtration temperature is 70-90 °C, and lithium carbonate product is obtained after drying.

[0036] The XRD spectrum of the lithium carbonate product obtained in this example is as Figure 2 shown, and the characteristic diffraction peaks of the product are the same as the standard spectrum Figure 1One-to-one correspondence; after detection, the purity of the lithium carbonate product is as Figure 3 shown to reach 98.5%, the direct recovery rate reaches 80.6%, and the sodium ion removal rate is 84.4%. It shows that the formation of micelles is insufficient, the chelation efficiency improvement is limited, and the recovery rate of methanol in the cycle is 96%.

[0037] Example 2

[0038] Step 1: Treat the leaching solution of aluminum electrolyte slag to obtain a mixed alkali metal sulfate solution (lithium ion content is 0.4 mol / L, sodium ion content is 0.85 mol / L). Add ethanol to the mixed sulfate at 25°C, and the volume ratio of the two is 1:3. After salting out, sodium sulfate precipitate is precipitated, and sodium sulfate crystals are obtained after drying.

[0039] Step 2: Add calixarene chelating agent (0.1 wt%) and Triton X-100 (0.5 wt%) to the supernatant 1 after centrifugation, stir at a constant temperature of 25°C for 15 min, and centrifuge to obtain supernatant 2 and precipitate.

[0040] Step 3: Add 0.2 mol / L sodium carbonate solution to the supernatant 2 obtained in Step 2 for carbonization crystallization reaction. The volume ratio of the sodium carbonate solution to the supernatant 2 is 1:4. After reacting for 10 minutes, centrifuge to obtain lithium carbonate precipitate and supernatant 3.

[0041] Step 4: Recover ethanol from the supernatant 3 obtained in Step 3 through an evaporation-condensation system. The evaporation temperature is 80°C, and the recovered ethanol is returned to the mixed sulfate solution.

[0042] Step 5: Obtain the lithium carbonate product after washing and drying with hot water.

[0043] The XRD pattern of the lithium carbonate product obtained in this example is as Figure 2 shown, and the characteristic diffraction peaks of the product correspond one-to-one with the standard spectrum Figure 1 One-to-one correspondence; after detection, the purity of the lithium carbonate product is as Figure 3 shown to reach 97.65%, the direct recovery rate is 78.52%, the sodium ion removal rate is 68.55%, too many micelles are formed by the surfactant itself, which may wrap the chelating agent, and low temperature (<25°C) reduces the reaction kinetics and the reaction efficiency.

[0044] Example 3:

[0045] Step 1: Treat the leaching solution of aluminum electrolyte slag to obtain a mixed alkali metal sulfate solution (lithium ion content is 0.55 mol / L, sodium ion content is 1.2 mol / L). Add ethanol and acetone to the mixed sulfate at 25°C, and the volume ratio of the mixed sulfate solution, ethanol and acetone is 2:1:1. After salting out, sodium sulfate precipitate is precipitated, and sodium sulfate crystals are obtained after drying.

[0046] Step 2: Add calixarene chelating agent (0.2 wt%) and Triton X-100 (0.3 wt%) to the supernatant 1 after centrifugation, stir at a constant temperature of 40 °C for 20 min, and perform centrifugal separation to obtain supernatant 2 and precipitate.

[0047] Step 3: Add 0.2 mol / L sodium carbonate solution to the supernatant 2 obtained in Step 2 for carbonization crystallization reaction. The volume ratio of the sodium carbonate solution to the supernatant 2 is 1:1.2. After reacting for 12 minutes, perform centrifugal separation to obtain lithium carbonate precipitate and supernatant 3.

[0048] Step 4: The supernatant 3 obtained in Step 3 is passed through an evaporation-condensation system to recover acetone and ethanol respectively. Acetone is recovered at an evaporation temperature of 56 °C, and ethanol is recovered at an evaporation temperature of 80 °C. The recovered organic solvents can be returned and added to the mixed sulfate solution.

[0049] Step 5: After washing and drying with hot water, a lithium carbonate product is obtained.

[0050] The XRD pattern of the lithium carbonate product obtained in this example is as Figure 2 shown. The characteristic diffraction peaks of the product correspond one by one to the standard spectrum Figure 1 ; After detection, the purity of the lithium carbonate product is as Figure 3 shown, reaching 99.14%, the direct recovery rate is 81.5%, and the sodium ion removal rate is 83.2%.

[0051] Example 4:

[0052] Step 1: Treat the leaching solution of aluminum electrolyte slag to obtain a mixed alkali metal sulfate solution (lithium ion content is 0.75 mol / L, sodium ion content is 1.2 mol / L). Add ethanol to the mixed sulfate at 25 °C. The volume ratio of the mixed sulfate solution to ethanol is 2:1. After salting out, sodium sulfate precipitate is separated out, and after drying, sodium sulfate crystals are obtained.

[0053] Step 2: Add calixarene chelating agent (1.0 wt%) and Triton X-100 (0.2 wt%) to the supernatant 1 after centrifugation, stir at a constant temperature of 55 °C for 10 min, and perform centrifugal separation to obtain supernatant 2 and precipitate.

[0054] Step 3: Add 0.2 mol / L sodium carbonate solution to the supernatant 2 obtained in Step 2 for carbonization crystallization reaction. The volume ratio of the sodium carbonate solution to the supernatant 2 is 1.5:1. After reacting for 10 minutes, perform centrifugal separation to obtain lithium carbonate precipitate and supernatant 3.

[0055] Step 4: The supernatant 3 obtained in Step 3 is passed through an evaporation-condensation system to recover ethanol. The evaporation temperature is 80 °C, and the recovered ethanol is returned and added to the mixed sulfate solution.

[0056] Step 5: After hot water washing and drying, a lithium carbonate product is obtained.

[0057] After testing, the purity of the lithium carbonate product obtained in this example reaches 98.15%, the direct recovery rate is 82.3%, and the sodium ion removal rate is 79.4%. High temperature (>55°C) during the reaction process will destroy the micelle structure, resulting in the dissociation of the chelate.

[0058] Example 5:

[0059] Step 1: After treating the leaching solution of aluminum electrolyte slag, a mixed alkali metal sulfate solution is obtained (lithium ion content is 0.75 mol / L, sodium ion content is 1.2 mol / L). At 25°C, acetone is added to the mixed sulfate. The volume ratio of the mixed sulfate solution to acetone is 2:1. After salting out, sodium sulfate precipitate is separated out, and after drying, sodium sulfate crystals are obtained.

[0060] Step 2: Calixarene chelating agent (0.5 wt%) and Triton X-100 (0.3 wt%) are added to the supernatant 1 after centrifugation. The mixture is stirred at a constant temperature of 40°C for 10 min, and then centrifuged to obtain supernatant 2 and precipitate.

[0061] Step 3: Add 0.2 mol / L sodium carbonate solution to the supernatant 2 obtained in Step 2 for carbonization crystallization reaction. The volume ratio of the sodium carbonate solution to the supernatant 2 is 1.5:1. After reacting for 10 minutes, it is centrifuged to obtain lithium carbonate precipitate and supernatant 3.

[0062] Step 4: The supernatant 3 obtained in Step 3 passes through an evaporation-condensation system to recover acetone. The evaporation temperature is 56°C, and the recovered acetone is returned to be added to the mixed sulfate solution.

[0063] Step 5: After hot water washing and drying, a lithium carbonate product is obtained.

[0064] After testing, the purity of the lithium carbonate product obtained in this example reaches 99.65%, the direct recovery rate is 89.05%, and the sodium ion removal rate is increased to 94%.

[0065] Comparative Example 1:

[0066] The composition of the mixed sulfate solution and the addition of carbonate are the same as in Example 4. The difference is that in this comparative example, calixarene chelating agent is not added to the mixed sulfate solution. The obtained suspension is centrifuged to obtain lithium carbonate precipitate and supernatant 3. After the precipitate is washed with hot water and dried, a lithium carbonate product is obtained.

[0067] Only lithium carbonate products with a purity of 94.1% and a direct yield of 34.74% are obtained. Since lithium carbonate is slightly soluble in water at 25°C, with a solubility of 1.29 g / 100 g (the critical saturation concentration is about 0.174 mol / L), the lithium ion concentration in the reaction system is 0.6 mol / L, and the theoretical yield is 42%. However, a large amount of sodium ions interfere with the carbonization reaction, resulting in a yield lower than the theoretical yield and much lower than that of Example 1, failing to meet the requirements for the efficient preparation of lithium carbonate.

[0068] Comparative Example 2:

[0069] The composition of the mixed sulfate solution and the addition of carbonate are the same as in Example 5, except that: in this comparative example, no surfactant was added in Step 2. The obtained suspension was centrifuged to obtain lithium carbonate precipitate and supernatant 3, and the lithium carbonate product was obtained after washing the precipitate with hot water and drying.

[0070] After the reaction, a lithium carbonate product with a purity of 98.9% and a direct yield of 56.96% was obtained, and the sodium ion removal rate was only 65%; the yield and purity were still lower than those of Example 1, and the effect was not good.

[0071] The description and drawings of the present invention are considered to be illustrative rather than restrictive. Based on the present invention, those skilled in the art can make some substitutions and deformations of some technical features without creative labor according to the disclosed technical content, and all are within the protection scope of the present invention.

Claims

1. A method for preparing lithium carbonate from aluminum electrolyte waste slag, characterized in that: The following steps are involved: S1, adding an organic solvent to the leachate obtained after roasting the aluminum electrolyte waste slag, wherein the volume ratio of the organic solvent to the leachate is 1:2-3:1, stirring at a constant temperature of 25°C for 5-10 minutes, and the stirring speed is 300-600r / min; centrifuging the suspension obtained by stirring to obtain a supernatant 1 and a sodium sulfate precipitate; S2, adding 0.1-1.0wt% of calixarene chelating agent and 0.2-0.5wt% of surfactant to the supernatant 1 obtained in S1, the reaction temperature is 25°C to 60°C, stirring the reaction for 10-20 minutes, and then separating the solid and the liquid to obtain a precipitate and a supernatant 2; S3, adding 0.06-0.3 mol / L carbonate solution to the supernatant 2 obtained in S2, wherein the volume ratio of the carbonate solution to the supernatant 2 is 1:1.5-1:3, stirring at a constant temperature for 10 minutes to perform a carbonization crystallization reaction, and obtaining a lithium carbonate precipitate and a supernatant 3 after centrifugal separation; S4. Wash the lithium carbonate precipitate obtained in S3 with hot water, and then dry it to obtain a lithium carbonate product.

2. The method according to claim 1, characterized in that The leaching solution obtained after the aluminum electrolyte waste slag is roasted has a lithium ion content of 0.4-0.75 mol / L and a sodium ion content of 0.8-1.2 mol / L.

3. The method according to claim 1, characterized in that: The surfactant is Triton X-100 or Tween20.

4. The method according to claim 1, characterized in that The carbonate is sodium carbonate or potassium carbonate.

5. The method according to claim 1, characterized in that The supernatant 3 obtained from S3 is passed through an evaporation-condensation system at a distillation temperature of 56 to 80° C. and a distillation pressure of normal atmospheric pressure to obtain an organic solvent and a sodium sulfate solution.

6. The method according to claim 1 or 5, characterized in that: The organic solvent is one of methanol, ethanol and acetone or a mixture of two of them.

7. The method according to claim 1, characterized in that In the S4, the lithium carbonate precipitate is washed with hot water at 60-80°C, the washing method is two leaching washes and one slurry wash, the solid-liquid ratio during washing is 1:5-1:10, and the filtration is hot at a filtration temperature of 70-90°C. The lithium carbonate product is obtained after drying.

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