Method for producing lithium hydroxide
By treating chelating resin and acid solution, combining distilled water and separating acid solution, the problem of impurities residue in lithium hydroxide solution is solved, and the preparation of high-purity lithium hydroxide is realized, which is suitable for cathode materials of high-performance lithium secondary batteries.
Patent Information
- Application Number
- CN202480006629.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-10-30
- Filing Date
- 2024-03-29
- Publication Date
- 2025-08-08
AI Technical Summary
There are cation residues such as impurities such as calcium ions in the existing lithium hydroxide manufacturing methods, which leads to a decrease in purity and makes it difficult to control the sodium ion mixture, affecting the performance of lithium secondary batteries.
The lithium hydroxide solution is ion exchanged with chelating resin, combined with acid solution and distilled water treatment, and then separated impurities with the separated acid solution, and the preparation of high-purity lithium hydroxide is achieved by controlling the proportion and concentration of each step.
It effectively removes calcium ion impurities in lithium hydroxide solution, controls it to the trace level, improves the purity of lithium hydroxide, and meets the requirements of high-density and high-capacity lithium secondary batteries.
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Figure CN120457089A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to methods of producing lithium hydroxide. Background Art
[0002] With the growing importance of environmentally friendly vehicles such as electric vehicles, demand for lithium secondary batteries (Li-ion batteries) as the primary energy storage device for electric vehicles has been increasing. Lithium is the core cathode material, which determines the capacity and voltage of Li-ion secondary batteries. However, since Li-ion is difficult to utilize in its pure form, it is processed and used as a compound.
[0003] The lithium compounds used in lithium secondary batteries primarily include lithium carbonate (Li2CO3) and lithium hydroxide (LiOH). Lithium hydroxide is primarily used as a cathode material in lithium secondary batteries for electric vehicles, which require high density and capacity, because it easily reacts with nickel, thereby increasing battery capacity. Therefore, there is a need to develop technologies to efficiently and economically obtain lithium hydroxide.
[0004] Generally, examples of methods for obtaining lithium hydroxide include: a method of extracting lithium hydroxide from mined lithium ore; a method of first producing lithium carbonate by evaporating brine extracted from a salt lake, and then converting the lithium carbonate into lithium hydroxide; and a method of extracting lithium phosphate from used lithium-ion batteries and then adding a phosphate anion precipitant to produce lithium hydroxide.
[0005] However, conventional lithium hydroxide production methods result in various cations, such as calcium and magnesium, remaining in the lithium hydroxide solution. These cations act as impurities in the lithium hydroxide production process, reducing the purity of the lithium hydroxide. To remove these impurities, precipitants such as sodium hydroxide and sodium carbonate can be added to the lithium hydroxide solution, and cations such as calcium and magnesium can be precipitated and removed using hydroxides. However, this approach can introduce sodium ions into the lithium mixture, reducing the purity of the lithium hydroxide, and there are limitations on controlling the impurity concentration to trace amounts.
[0006] Therefore, a method for producing high-purity lithium hydroxide without sodium ion admixture and controlling the impurity concentration to trace amounts is needed. Summary of the Invention
[0007] In view of the above background, the present disclosure is directed to producing high-purity lithium hydroxide by removing cationic impurities from a lithium hydroxide solution containing cationic impurities and lithium ions.
[0008] Furthermore, the present disclosure aims to control the concentration of calcium ions among impurities contained in the lithium hydroxide solution to a trace amount.
[0009] One embodiment of the present disclosure provides a method for producing lithium hydroxide, comprising: a solution preparation step of preparing a lithium hydroxide solution containing impurities and lithium ions; and a lithium hydroxide solution passing step of passing the lithium hydroxide solution through a chelating resin, wherein, during the passage of the lithium hydroxide solution through the chelating resin, ions contained in the impurities are exchanged with ions bound to the chelating resin and are bound to the chelating resin, and the lithium ions pass through the chelating resin.
[0010] In the method according to one embodiment of the present disclosure, the impurities may include calcium ions (Ca 2+ ), and the lithium hydroxide solution in the solution preparation step contains calcium ions at a concentration of 20 ppm to 25 ppm.
[0011] In the method according to one embodiment of the present disclosure, the lithium hydroxide solution may be provided so that the volume ratio of the lithium hydroxide solution passing through the chelating resin relative to the volume ratio of the chelating resin is 16.7 to 83.3 times.
[0012] According to one embodiment of the present disclosure, the method may further include a combined acid solution passing step of passing the combined acid solution through the chelating resin, wherein the combined acid solution passing step is performed between the solution preparation step and the lithium hydroxide solution passing step, wherein, during the period when the lithium hydroxide solution passes through the chelating resin, the ions contained in the impurities are exchanged with the hydrogen ions bound to the chelating resin.
[0013] In the method according to one embodiment of the present disclosure, the combined acid solution may have an acid concentration of 60 g / L to 90 g / L.
[0014] In the method according to one embodiment of the present disclosure, the combined acid solution may be provided such that the volume ratio of the combined acid solution passing through the chelating resin relative to the volume ratio of the chelating resin is 4 to 8 times.
[0015] According to one embodiment of the present disclosure, the method may further include a distilled water passing step of passing distilled water through the chelating resin, wherein the distilled water passing step is performed between the combined acid solution passing step and the lithium hydroxide solution passing step.
[0016] In the method according to one embodiment of the present disclosure, the distilled water may be provided such that the volume ratio of the distilled water to the chelating resin is 1.5 to 6 times.
[0017] According to one embodiment of the present disclosure, the method may further include a separation acid solution passing step of passing the separation acid solution through a chelating resin bound to the impurities, wherein the separation acid solution passing step is performed after the lithium hydroxide solution passing step, wherein, during the period when the separation acid solution passes through the chelating resin, the impurities bound to the chelating resin are exchanged with hydrogen ions of the separation acid solution.
[0018] According to an embodiment of the present disclosure, the separation acid solution may have an acid concentration of 60 g / L to 90 g / L.
[0019] In the method according to one embodiment of the present disclosure, the separating acid solution may be provided such that the volume ratio of the separating acid solution passing through the chelating resin relative to the volume ratio of the chelating resin is 5 to 6.7 times.
[0020] According to the present disclosure, high-purity lithium hydroxide can be produced by removing cationic impurities from a lithium hydroxide solution containing both cationic impurities and lithium ions.
[0021] Furthermore, the concentration of calcium ions among the impurities contained in the lithium hydroxide solution can be controlled to a trace amount. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [ Figure 1 ] is a flow chart sequentially showing a method for producing lithium hydroxide according to one embodiment of the present disclosure.
[0023] [ Figure 2 ] is the analysis result figure that shows the ratio according to lithium hydroxide solution amount to chelating resin amount.
[0024] [ Figure 3 ] is a diagram showing the analysis results of the ratio of the amount of bound acid solution to the amount of chelating resin.
[0025] [ Figure 4 ] is the analysis result figure that shows the ratio according to the distilled water amount to the resin amount.
[0026] [ Figure 5 ] is the analysis result figure that shows the ratio according to separation acid solution amount to chelating resin amount. DETAILED DESCRIPTION
[0027] For the purpose of explaining the technical concept of the present disclosure, embodiments of the present disclosure are described. The scope of rights according to the present disclosure is not limited to the embodiments presented below or the detailed description of such embodiments.
[0028] Hereinafter, a description of the present disclosure will be provided with reference to the accompanying drawings.
[0029] Figure 1The flowchart sequentially shows a method for producing lithium hydroxide according to one embodiment of the present disclosure.
[0030] Reference Figure 1 , the method for producing lithium hydroxide (S1) can produce a high-purity lithium hydroxide solution. In this article, the lithium hydroxide solution refers to a solution in which lithium hydroxide (LiOH) is dissolved, and the method for producing lithium hydroxide (S1) means that the lithium hydroxide is produced in the form of an aqueous solution. For example, the method for producing lithium hydroxide (S1) can be a series of lithium hydroxide purification methods, which remove cationic impurities from a lithium hydroxide solution containing cationic impurities to obtain a high-purity lithium hydroxide solution. In this case, the method for producing lithium hydroxide (S1) can produce a lithium hydroxide solution from which the cationic impurities have been removed.
[0031] Solution preparation step (S100)
[0032] The method for producing lithium hydroxide (S1) includes a solution preparation step (S100) of preparing a lithium hydroxide solution containing impurities and lithium ions. In the solution preparation step (S100), the lithium hydroxide solution can be prepared by various methods. For example, the lithium hydroxide solution can be obtained from lithium-containing ores, such as spodumene, lepidolite, pyroxenite, or petalite. Alternatively, the lithium hydroxide solution can be obtained by oxidizing lithium carbonate using calcium hydroxide (Ca(OH)2). Another example is that the lithium hydroxide solution can be obtained from a used lithium ion battery. The following will focus on preparing the lithium hydroxide solution from a used lithium ion battery, but this is only an example and the present disclosure is not limited to this.
[0033] In the solution preparation step (S100), lithium carbonate (LiCO) extracted from a used lithium-ion battery can be used to obtain a lithium hydroxide solution. For example, a lithium carbonate filter cake can be reacted with calcium oxide (CaO) and water at 70°C to 80°C for 2 to 3 hours to obtain a lithium hydroxide solution (according to Reaction Formula 1).
[0034] (Reaction 1)
[0035] In the solution preparation step (S100), the lithium hydroxide solution may contain one or more of the following cationic impurities: aluminum ions (Al 3+ ), barium ions (Ba 2+ ), calcium ions (Ca 2+ ), iron ions (Fe 2+ 、Fe 3+ ), magnesium ions (Mg 2+ ), and lead ions (Pb 2+). In particular, according to Reaction Formula 1, the lithium hydroxide solution may contain a high concentration of calcium ions, and the calcium ion concentration in the lithium hydroxide solution may be 20 ppm to 25 ppm. In addition, in the solution preparation step (S100), the lithium hydroxide solution may contain lithium ions, and the concentration of these lithium ions may be 8 g / L to 12 g / L.
[0036] The lithium hydroxide solution passes through step (S200)
[0037] The method (S1) of making lithium hydroxide comprises that lithium hydroxide solution is passed through step (S200), wherein lithium hydroxide solution is by chelate resin, and ions contained in the impurities are combined with chelate resin.For example, chelate resin can be IDA porous chelate resin based on styrene matrix.Chelate resin is a kind of cation exchange resin, and depends on the type of ion, has different selectivity and adsorption characteristics.Usually, the selectivity of cation exchange resin to cation is greater than that to lithium ion for calcium ion.Because the selectivity of chelate resin to calcium ion is greater than that to lithium ion, when lithium hydroxide solution flows through chelate resin, calcium ion and the hydrogen ion exchange that chelate resin is combined with make the lithium ion contained in lithium hydroxide solution be able to pass through resin.
[0038] During lithium hydroxide solution passes through step (S200), lithium hydroxide solution can be provided to pass through resin.When lithium hydroxide solution passes through resin, ion contained in the impurity is combined with the hydrogen ion exchange of resin, and lithium ion contained in the lithium hydroxide solution can pass through. In other words, ion contained in the impurity of lithium hydroxide solution is combined with resin, and the hydrogen ion combined with resin is released. For example, ion contained in the lithium hydroxide solution impurity can be calcium ion, which can be combined with the hydrogen ion exchange of resin. Other positively charged ions beyond the lithium ion are also the same.
[0039] In lithium hydroxide solution, by in step (S200), lithium hydroxide solution can be provided, makes the ratio of the amount of the lithium hydroxide solution by resin to the amount of resin in 16.7 to 83.3 scopes.That is, the volume ratio of the amount of the lithium hydroxide solution provided by step (S200) at lithium hydroxide solution relative to the amount of described resin is 16.7 times to 83.3 times. For example, if volume ratio is less than 16.7, then relative to the resin amount, the lithium hydroxide solution amount by resin is too few, and economically disadvantageous thus. If volume ratio surpasses 83.3, impurity may not fully remove from lithium hydroxide solution. In this article, in order to distinguish with the prepared lithium hydroxide solution containing impurity in solution preparation step (S100), the lithium hydroxide solution that has been removed impurity by resin is named as by rear lithium hydroxide solution.
[0040] Combined acid solution through step (S300)
[0041] The method for producing lithium hydroxide (S1) may include a combined acid solution passing step (S300) of allowing the combined acid solution to pass through a chelating resin to allow hydrogen ions (H + ) is combined with the chelate resin. The combined acid solution passing step (S300) can be carried out between the solution preparation step (S100) and the lithium hydroxide solution passing step (S200). During the combined acid solution passing step (S300), as it passes through the chelate resin, the ions originally bound to the chelate resin can be exchanged with the hydrogen ions in the combined acid solution. For example, if the ions originally bound to the chelate resin are sodium ions (Na + ), then when in conjunction with acid solution by resin, in conjunction with the hydrogen ion in the acid solution can experience and the ion exchange that is bonded to the sodium ion of resin, and be bonded to resin.Yet this is just illustrative example, and the ion that was originally bonded with resin also can be hydrogen ion.For this respect, in conjunction with acid solution by during step (S300), can remove the coating on the resin surface in conjunction with the acid solution of resin.In addition, can be hydrochloric acid (HCl) and sulfuric acid (H SO ) in at least one solution in conjunction with acid solution.Can be 60 g / L to 90 g / L in conjunction with the acid concentration in the acid solution.
[0042] In conjunction with acid solution, by in step (S300), can provide conjunction with acid solution, make by the ratio of the conjunction with acid solution amount to the resin amount in 4 to 8 scopes of resin.That is, the volume ratio of the amount of conjunction with acid solution that provides in step (S300) by the amount of described resin is 4 times to 8 times.For example, if volume ratio is less than 4, then may not have enough hydrogen ions to fully combine with resin, and if volume ratio surpasses 8, then do not have more hydrogen ions to combine with resin, and this is disadvantageous economically.
[0043] Distilled water passes through step (S400)
[0044] The method (S1) of making lithium hydroxide can comprise that distilled water passes through step (S400), is in conjunction with acid solution after step (S300), with distilled water by resin to remove the conjunction with acid solution still on the resin.Described distilled water can be between described conjunction with acid solution by step (S300) and described lithium hydroxide solution by step (S200) and carry out.In this article, the remaining conjunction with acid solution on resin refers to the conjunction with acid solution that does not experience ion exchange and remains in the resin surface when passing through resin.For example, if lithium hydroxide solution, by step (S200) period, remains in uncombined conjunction with acid solution on the resin and mixes with lithium hydroxide solution, then sulphur (S) or chlorine (Cl) may be as impurity, pollute the process solution in the subsequent procedure.In these situations, distilled water is passed through resin to clean and remove residual conjunction with acid solution, can prevent sulphur or chlorine from sneaking into the lithium hydroxide solution by resin.
[0045] In distilled water, by in step (S400), the distilled water amount can be provided, and making the ratio of the distilled water amount and the resin amount is 1.5 to 6. That is, the volume ratio of the amount of the distilled water that provides in distilled water by step (S400) with respect to the amount of resin is 1.5 times to 6 times.For example, if volume ratio is less than 1.5, then remaining in conjunction with acid solution may not fully remove.If volume ratio surpasses 6, then the amount of distilled water becomes excessive, and this is disadvantageous economically.
[0046] Separate the acid solution through step (S500)
[0047] The method (S1) of manufacturing lithium hydroxide may include separating an acid solution by step (S500), passing the separated acid solution through a chelate resin combined with impurities so that the impurities are separated from the chelate resin. The separated acid solution by step (S500) may be carried out after the lithium hydroxide solution is passed through step (S200). This step is intended to separate the impurities combined with the chelate resin during the lithium hydroxide solution by step (S200) so that the chelate resin can be reused. When the separated acid solution passes through the chelate resin combined with impurities, the impurity ions combined with the chelate resin can be exchanged with the hydrogen ions of the separated acid solution. That is, the hydrogen ions of the separated acid solution are combined with the chelate resin, and the calcium ions combined with the chelate resin are separated from the chelate resin. For example, the separated acid solution can be sulfuric acid (H2SO4) or hydrochloric acid (HCl). The acid concentration in the separated acid solution can be 60 g / L to 90 g / L.
[0048] At separation acid solution, by in step (S500), separation acid solution can be provided, and making the separation acid solution by resin is 5 to 6.7 to the ratio of resin. That is, separation acid solution is 5 times to 6.7 times by the volume ratio of the amount of the separation acid solution that provides in the step (S500) with respect to the amount of resin. For example, if volume ratio is less than 5, then foreign ions may not fully separate from resin. If volume ratio surpasses 6.7, then the amount of separation acid solution becomes excessive, and is disadvantageous economically thus.
[0049] Hereinafter, an embodiment of a method for producing lithium hydroxide according to the present disclosure will be described.
[0050] Analytical results based on the ratio of the amount of lithium hydroxide solution to the amount of chelating resin
[0051]
[0052] In table 1, embodiment 1 to 7 is carried out under identical experimental condition, and the amount of lithium hydroxide solution is different.That is, the experimental change in table 1 is the ratio of the amount of the lithium hydroxide solution of resin to the amount of resin. Figure 2 Can find out, when the amount of lithium hydroxide solution to the ratio of the amount of resin is between 16.7 and 83.3 (embodiment 1 to 5), impurity is through fully removing, and the removal rate of calcium ion after display reaction is between 90.6% and 92.8%.Therefore, when the amount of lithium hydroxide solution and the ratio of the amount of resin are at least 16.7, as in embodiment 1, can prevent the amount of the lithium hydroxide solution by resin from being too low. When the amount of lithium hydroxide solution to the ratio of the amount of resin is to reach 83.3, as in embodiment 5, from the impurity of lithium hydroxide solution is through fully removing (90% or higher removal rate), bring remarkable effect.
[0053] Analytical results based on the ratio of the amount of acid solution used for binding to the amount of chelating resin
[0054]
[0055] In Table 2, embodiment 8 to 12 is carried out under identical experimental condition, and the amount of in conjunction with acid solution is different.That is, the experimental change in Table 2 is the ratio of the amount of in conjunction with acid solution of resin to the amount of resin.In these embodiments, the sulfuric acid solution of use concentration 60 g / L is as in conjunction with acid solution. Figure 3Can find out, when the amount of sulphuric acid soln is to the ratio of the amount of resin between 4 and 8 (embodiment 9 to 11), sulphuric acid soln fully reacts, and the concentration of sulphuric acid soln after the display reaction becomes between 52.7g / L and 59.5g / L.Therefore, when the amount of sulphuric acid soln is to the ratio of the amount of resin at least 4, as among embodiment 9, this causes remarkable effect to the binding rate of hydrogen ion.When the amount of sulphuric acid soln is to the ratio of the amount of resin to reach 8, as among embodiment 11, prevent the amount of sulphuric acid soln from becoming too large, and keep the binding rate of hydrogen ion at a specific degree.
[0056] Analysis results based on the ratio of distilled water to chelating resin
[0057]
[0058] In table 3, embodiment 13 to 20 is carried out under identical experimental condition, and the amount of distilled water is different.That is, the experiment in table 3 changes the ratio of the amount of the distilled water of resin to the amount of resin. From table 3 and Figure 4 Can find out, when the amount of distilled water is between 1.5 and 6 when (embodiment 15 to 18) to the ratio of the amount of resin, sulphuric acid soln is through fully removing, and the concentration of sulphuric acid soln becomes between 17.7g / L and 0.07g / L after the display reaction.Therefore, when the amount of distilled water is at least 1.5 when to the ratio of the amount of resin, as among embodiment 15, this causes remarkable effect to the remaining removal in conjunction with acid solution.When the amount of distilled water is to reach 6 when to the ratio of the amount of resin, as among embodiment 18, prevent that the amount of distilled water from becoming excessive, and keep the remaining removal rate in conjunction with acid solution at a specific degree.
[0059] Analytical results based on the ratio of the amount of separating acid solution to the amount of chelating resin
[0060]
[0061] In table 4, embodiment 21 to 25 is carried out under identical experimental condition, and the amount of separating acid solution is different.That is, the experimental change in the table 4 is the ratio of the amount of separating acid solution by resin to the amount of resin.In these embodiments, the sulfuric acid solution of use concentration 90 g / L is as separating acid solution. From table 4 and Figure 5Can find out, when the amount of sulphuric acid solution is between 5 and 6.7 to the ratio of the amount of resin (embodiment 23 to 24), display calcium ion fully separates from resin, causes the calcium ion cumulative recovery between 88.2% and 88.8%.Therefore, when the amount of separating acid solution is at least 5 to the ratio of the amount of resin, as in embodiment 23, this fully separates and causes remarkable effect to impurity from resin.When the amount of separating acid solution is to reach 6.7 to the ratio of the amount of resin, as in embodiment 24, can prevent the amount of sulphuric acid solution from becoming excessive, and keep the desorption rate of impurity at a specific degree.
[0062] While the exemplary embodiments of the present disclosure have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that the present disclosure may be implemented in another specific form without changing the technical spirit or essential characteristics thereof.
[0063] Therefore, it is understood that the above exemplary embodiments are illustrative to describe all embodiments rather than limiting, and it is understood that the scope of the present disclosure should be represented by the scope of the claims described below, and all changes or modifications inferred from the meaning and scope of the claims, as well as their equivalent concepts, are included in the scope of the present disclosure.
Claims
1. A method for producing lithium hydroxide, the method comprising: A solution preparation step for preparing a lithium hydroxide solution containing impurities and lithium ions; as well as The lithium hydroxide solution is passed through a lithium hydroxide solution passing step of a chelating resin, Wherein, while the lithium hydroxide solution passes through the chelate resin, the ions contained in the impurities are exchanged with the ions bound to the chelate resin and are bound to the chelate resin, and the lithium ions pass through the chelate resin.
2. The method according to claim 1, wherein The impurities include calcium ions (Ca 2+ ),and The lithium hydroxide solution in the solution preparation step contains calcium ions at a concentration of 20 ppm to 25 ppm.
3. method according to claim 1, wherein said lithium hydroxide solution is provided, and the volume ratio that makes said lithium hydroxide solution pass through the amount of said resin relative to the amount of said resin is 16.7 times to 83.3 times.
4. method according to claim 1, it further comprises the in conjunction with acid solution by the in conjunction with acid solution of described resin by step, wherein said in conjunction with acid solution by step is to carry out between described solution preparation step and described lithium hydroxide solution by step, in, While the lithium hydroxide solution passes through the chelate resin, ions contained in the impurities are exchanged with hydrogen ions bound to the chelate resin. The method according to claim 4 , wherein the combined acid solution has an acid concentration of 60 g / L to 90 g / L.
6. method according to claim 4, wherein said combined acid solution is provided, and the volume ratio that makes said combined acid solution pass through the amount of said chelating resin relative to the amount of said chelating resin is 4 times to 8 times.
7. method according to claim 4, further comprises the distilled water that distilled water is passed through described resin by step, The step of passing the distilled water is performed between the step of passing the combined acid solution and the step of passing the lithium hydroxide solution.
8. method according to claim 7, wherein said distilled water is provided, and the volume ratio that makes the amount of said distilled water relative to the amount of said resin is 1.5 times to 6 times.
9. method according to claim 1, it further comprises separating acid solution by the separating acid solution of the resin bonded with said impurity by step, wherein said separating acid solution is to carry out after said lithium hydroxide solution by step by step, in, During the period when the separation acid solution passes through the chelate resin, the impurities bound to the chelate resin are exchanged with hydrogen ions of the separation acid solution. 10 . The method according to claim 9 , wherein the separating acid solution has an acid concentration of 60 g / L to 90 g / L.
11. method according to claim 9, wherein said separating acid solution is provided, and the volume ratio of the amount that makes said separating acid solution pass through said chelating resin relative to the amount of said chelating resin is 5 times to 6.7 times.