JP2009269810A - Method for producing high-purity lithium hydroxide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which lithium hydroxide which cannot be stored for quite a while and is incapable of domestic stockpile can be produced as needed. <P>SOLUTION: Aqueous lithium chloride solutions are obtained from lithium carbonate, a lithium-bearing ore and a used lithium-ion secondary battery each capable of stockpiling with hydrochloric acid, or an aqueous lithium chloride solution is prepared using powder of lithium chloride separated from lithium-containing brine by adsorption with an inorganic adsorbent, and each of the aqueous lithium chloride solutions is subjected to bipolar membrane electrodialysis to simultaneously produce hydrochloric acid and an aqueous lithium hydroxide solution. The hydrochloric acid is reacted with a stored lithium source so as to repeatedly obtain lithium chloride. The aqueous lithium hydroxide solution is passed through a purification step where the impurities are diminished or removed and high-purity lithium hydroxide monohydrate is obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

Detailed Description of the Invention

Industrial application fields

The present invention relates to a method for producing high purity lithium hydroxide useful as a raw material for a lithium ion secondary battery positive electrode material, a raw material for a ceramic material, and a raw material for a high purity lithium compound.

In recent years, lithium hydroxide has been used as a lithium source for producing a positive electrode active material for lithium ion secondary batteries and LiPF ₆ as an electrolyte, and as a raw material for electronic devices such as lithium niobate and lithium tantalate as SAW filter materials. Has been.
Further, it is desired to further reduce impurities contained in lithium hydroxide for precise material design.
In a conventional method for producing lithium hydroxide, lithium carbonate contained in irrigation is taken out as lithium carbonate, and calcium hydroxide is generally added to make lithium hydroxide. In order to reduce impurities, lithium hydroxide is deposited and separated near the boiling temperature of water, and the device has been devised to reduce the sodium content by utilizing the difference in solubility between sodium hydroxide and lithium hydroxide in hot water. There is a limit, and calcium, sodium, chloride ions, and sulfate ions are contained in lithium hydroxide monohydrate by several tens of ppm, and it is necessary to further refine the impurities in order to reduce impurities.
In addition, production at overseas sites where ore or irrigation as a lithium source is collected is common. From the standpoint of ensuring domestic stability as a raw material that must be transported over long distances, the risk has increased with the recent increase in demand.
Lithium hydroxide absorbs carbon dioxide in the air during storage and is easily transformed into lithium carbonate. It also solidifies or becomes a lump after 3 to 6 months of storage and storage, which hinders powder handling operations. Therefore, it was necessary to manufacture and supply the necessary amount at the time of use without using long-term storage. Because of its poor storage properties, it was difficult to stockpile lithium hydroxide produced overseas as a raw material in Japan.
In the current situation of relying on imports from overseas, there was a difficulty in terms of securing a stable quantity in terms of logistics. In response to the rapidly increasing demand, there has been a demand for the development of a technology that can secure the degree of freedom of delivery to domestic customers and that can be manufactured quickly and efficiently.

Problems to be solved by the invention

Focusing on lithium carbonate, lithium chloride, and lithium-containing ore that can be stored as a lithium source with little deterioration even after long-term storage, and used lithium-ion secondary batteries as stored lithium resources. It is an object of the present invention to provide a simple production method capable of producing lithium hydroxide at any time so as to meet the predicted quantity of lithium hydroxide required as a raw material in Japan.

Means for solving the problem

As a result of various studies on the above problems, the present inventor has paid attention to lithium chloride, and obtained lithium hydroxide aqueous solution by bipolar membrane electrodialysis using lithium chloride aqueous solution obtained by dissolving lithium chloride in water, while repeatedly using hydrochloric acid produced simultaneously. The present inventors have found that the present invention can be accomplished and have completed the present invention. (1) Lithium carbonate that can be stored in a large amount in Japan is used as a starting material and reacted with hydrochloric acid to obtain a lithium chloride aqueous solution, which is then subjected to bipolar membrane electrodialysis. (2) A lithium chloride aqueous solution is obtained by hydrochloric acid treatment from lithium-containing ore that is a lithium resource other than irrigation that can be stored in large quantities in Japan and is subjected to bipolar membrane electrodialysis. (3) When recovering the resources of the used lithium secondary battery, an aqueous lithium chloride solution is obtained from the lithium salt electrolyte and the lithium transition metal composite oxide of the positive electrode active material by hydrochloric acid treatment and subjected to bipolar membrane electrodialysis.
(4) A lithium chloride powder selectively adsorbed and separated from the irrigation is stored and, as needed, made into a lithium chloride aqueous solution and subjected to bipolar membrane electrodialysis. In this way, hydrochloric acid is obtained and used repeatedly, while a purification process is added to the aqueous lithium hydroxide solution to remove or reduce impurities, thereby producing a high purity lithium hydroxide.

The present invention will be specifically described below.
That is, the present invention relates to a method for obtaining lithium hydroxide that cannot be stored for a long period of time, that is, cannot be stored, using lithium chloride as a starting material. When lithium hydroxide is required, it is found that lithium chloride aqueous solution in which lithium chloride is dissolved in water is used to obtain the desired lithium hydroxide aqueous solution by bipolar membrane electrodialysis, while simultaneously produced hydrochloric acid can be used repeatedly. The present invention has been completed as a resource. (1) Lithium carbonate that can be stored in large quantities in Japan is reacted with hydrochloric acid to obtain a lithium chloride aqueous solution, and a bipolar membrane, an anion exchange membrane and an intestinal ion exchange membrane are used between the anode and the cathode. In addition, an acid chamber and an alkali chamber are formed, and an aqueous solution of lithium chloride is supplied to the salt chamber to obtain hydrochloric acid by bipolar membrane electrodialysis that can take out hydrochloric acid from the acid chamber and an aqueous lithium hydroxide solution from the alkaline chamber, respectively, A method for producing high-purity lithium hydroxide, wherein impurities are removed or reduced by a purification step of a lithium hydroxide aqueous solution. A method of repeatedly using hydrochloric acid produced at the same time for reaction with lithium carbonate while obtaining an aqueous lithium hydroxide solution. (2) Lithium-containing ore which is a lithium resource other than irrigation and can be stored in large quantities by hydrochloric acid treatment. A method in which an aqueous lithium chloride solution is obtained and a lithium hydroxide aqueous solution is obtained by bipolar membrane electrodialysis, while hydrochloric acid produced at the same time is repeatedly used. (3) Lithium salt electrolyte, positive electrode activity for resource recovery of used lithium secondary batteries A method of using lithium chloride aqueous solution by treatment with hydrochloric acid from lithium transition metal composite oxide of the substance and obtaining lithium hydroxide aqueous solution by bipolar membrane electrodialysis while repeatedly using hydrochloric acid produced simultaneously (4) Selectively from irrigation Store the adsorbed and separated lithium chloride powder as needed in an aqueous lithium chloride solution. It is to use repeatedly hydrochloric acid while being produced at the same time obtain a lithium hydroxide aqueous solution by bipolar membrane electrodialysis Te.

In order to obtain the lithium hydroxide of the present invention, a bipolar membrane and an anion exchange membrane are used between an anode and a cathode using an electrodialyzer composed of an alkali-resistant material and an acid-resistant material and not contaminated by corrosion. And forming a salt chamber, an acid chamber and an alkali chamber using a cation exchange membrane, supplying an aqueous solution of lithium chloride to the salt chamber, taking out hydrochloric acid from the acid chamber and removing the lithium hydroxide aqueous solution from the alkali chamber, respectively. A purification process is added to the lithium oxide aqueous solution to remove or reduce impurities.

For example, iminodiacetic acid type or aminophosphate type chelating resins can be used as the chelating agent for adsorbing and removing alkaline earths such as calcium and magnesium and trace amounts of metal ions in the purification step. The space velocity (SV) in the column is usually 2 to 10 hr ⁻¹ in the purification operation. Further, since it is often shipped as a sodium salt, it is converted to a lithium salt with an acid treatment, water washing, and an aqueous solution of 9-11% high-purity lithium hydroxide concentration. Although not particularly limited, lithium salts of Amberlite IRC748 (manufactured by Organo) and Amberlite IRC747 (manufactured by Organo) are used.

Reduction or removal of monovalent alkali ions other than lithium, such as sodium and potassium, and sulfonic acid groups of cross-linked polymers with styrene / divinylbenzene as cation exchange resins for complete adsorption and removal of divalent alkaline earth calcium and magnesium A weakly acidic cation exchange resin having a functional group as a base and a weakly acidic cation exchange resin based on a copolymer of acrylic acid or methacrylic acid and divinylbenzene having a carboxylic acid group as a functional group can be used. Either the RH type that releases hydrogen ions or the R-Li type that releases Li cations according to the amount of impurities can be used.

Chloromethylated copolymer of styrene and divinylbenzene as anion exchange resin that adsorbs and reduces or removes anions such as chloride ion, sulfate ion and hydrogen carbonate ion, and then uses trimethylamine, dimethylamine and dimethylethanolamine. Use aminated product.

In the purification step of the present invention, the chelating agent, cation exchange resin, or anion exchange resin can be used after concentration to a concentration close to the upper limit of the solubility of lithium hydroxide in water.
In addition, if necessary, the residual liquid in which lithium hydroxide is precipitated is again subjected to such purification treatment, concentrated impurities are removed, and then the precipitate is dehydrated and dehydrated and dried in hot water. The yield of lithium oxide can be increased.

The lithium hydroxide monohydrate obtained in the present invention can be made into high-purity lithium carbonate by reacting with carbon dioxide gas, or dehydrated to obtain lithium hydroxide anhydride as a positive electrode active material for a lithium ion secondary battery It is used as a lithium source for producing LiPF ₆ as an electrolyte, and as a raw material for electronic devices such as lithium niobate and lithium tantalate as SAW filter materials. In addition, if it is made highly purified lithium carbonate, it can be stored, and if the lithium carbonate aqueous solution of the present invention is electrolyzed after long-term storage, a purification step is unnecessary, and high purity lithium hydroxide can be obtained at any time. .

As the lithium chloride used in the present invention, even commercially available lithium chloride can be used after reducing or removing impurities by a conventional method, if necessary.

As the lithium chloride used in the present invention, an aqueous lithium chloride solution prepared by stocking lithium carbonate in Japan from the viewpoint of stocking a large amount of lithium resources and reacting with hydrochloric acid at any time is used.

The lithium chloride used in the present invention is obtained by extracting from lithium-containing ore using hydrochloric acid. Examples of the lithium-containing ore used in the present invention include lithia pyroxene (also called spodumene. Typical examples include LiAlSi ₂ O ₆ ), eucryptite (typical composition, LiAlSiO ₄ ), petalite ( Typical composition, LiAlSi ₄ O ₁₀ ), red mica (also called Lithia mica. Typical composition, K ₄ Mg ₄ Li ₄ Al ₃ Si ₁₂ O ₄₀ ) (OH) ₄ F4), chinwald mica (typical composition, K (Li, Fe, Al) ₃ (AlSi ₃ O ₁₀ ) (F, OH), manadnite (typical composition, H ₂₄ Li ₄ Al ₁₄ B ₄ Si ₆ O ₅₃ ), trifilite (typical composition, Li (Fe , Mn) PO4 with more Fe than Mn), Liciophyllite (typical composition, Li (Fe, Mn) PO4 with Mn content of F More than a minute), ambrigolite (typical composition, (Li, Na) Al (PO4) (F, OH)), Fremontite (also called Natromon bracite or natroambrigonite. Li) Al (PO ₄ ) (OH, F), Sickler stone (typical composition, (Li, Mn, Fe) (PO ₄ )) and the like.

The lithium chloride used in the present invention is obtained by reacting hydrochloric acid with lithium content in a lithium-containing electrolyte such as LiPF6 from a used lithium ion secondary battery and a lithium transition metal composite oxide contained in a positive electrode active material. Lithium chloride.

As lithium chloride used in the present invention, lithium-containing irrigation is passed through a column containing a pellet of Al (OH) ₃ having a layered structure such as gibbsite (gibbstone), bauxite, norstrandite, bayerite, etc. LiCl / Al (OH) 3 was selectively adsorbed and obtained lithium chloride. Lithium chloride obtained by selectively adsorbing with an aluminum hydroxide layered compound on a lithium chloride aqueous solution obtained by extracting hydrochloric acid from the lithium-containing ore may also be used. Hydrochloric acid obtained by bipolar membrane electrodialysis can also be used for the regeneration of such layered compounds.

The electrodialysis apparatus that can be used in the present invention can be used as a material as long as it can withstand strong alkali and hydrochloric acid. For example, a plastic container such as polypropylene can be used.
The apparatus is composed of a salt chamber, an acid chamber and an alkali chamber using a bipolar membrane, an anion exchange membrane and a cation exchange membrane between the anode and the cathode. This is a bipolar membrane electrodialysis apparatus configuration in which an aqueous solution of lithium chloride is supplied to a salt chamber so that hydrochloric acid can be taken out from the acid chamber and an aqueous lithium hydroxide solution can be taken out from the alkaline chamber.

The cation exchange membrane used in the present invention is a membrane that can pass a monovalent cation (such as lithium), and has at least a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, a sulfate ester group, and a phosphate ester group. Any film made of a polymer having one or more kinds may be used.
Fluorine cation exchange membranes with sulfonic acid groups, cation exchange membranes with perfluorocarboxylic acid groups introduced, and cation exchange membranes of perfluorovinyl copolymers with functional groups of ethylene tetrafluoride and carboxylic acid / sulfonic acid Further, there are a cation exchange membrane in which a membrane of a perfluorocarboxylic acid polymer and a perfluorosulfonic acid polymer is bonded, a cation exchange membrane in which a perfluorosulfonic acid polymer and a perfluorocarboxylic acid polymer are laminated, and the like. Attaching reinforcing fibers, further improving the selective permeability of monovalent cations to suppress the passage of multivalent ions such as calcium and magnesium that permeate the cation exchange membrane, and anions such as OH ions and chloride ions In addition, additives may be applied for the purpose of suppressing or eliminating the passage of sulfate ions, the surface layer surface may have a dense structure, or other films may be bonded together. Neoceptor CMV, Neoceptor CMB, Neoceptor CMS, Neoceptor CMT, Neoceptor CIMS, Neoceptor CL-25T, Neoceptor CMD, Neoceptor CM-2, Neoceptor CSO (above, manufactured by Tokuyama Corporation, trade name) ), Selemion CMV, Selemion CAV, Selemion CSV (Asahi Glass Co., Ltd., trade name), FKF, FKC, FKL, FKE (Fumatech Co., Ltd., trade name), Nafion 324, Nafion 117, Nafion 115 (DuPont, trade name) ) Etc.

The anion exchange membrane used in the present invention has a high basic group having a weak basic functional group such as a primary amino group, a secondary amino group, and a tertiary amino group in a strong basic group of a quaternary ammonium group. Any film made of molecules may be used.
Neoceptor ACM, Neoceptor AM-1, Neoceptor ACS, Neoceptor ACLE-5P, Neoceptor AHA, Neoceptor AMH, Neoceptor ACS (above, Tokuyama Co., Ltd., trade name), Selemion AMV, Selemion AAV ( Asahi Glass Co., Ltd., trade name), FAB, FAA (Fumatech Co., trade name) and the like.

The bipolar membrane used in the present invention is not particularly limited as long as it is a composite membrane having a structure in which a cation exchange membrane and an anion exchange membrane are bonded together.
Treating the interface between the cation exchange membrane and the anion exchange membrane with an inorganic compound, depositing a mixture of both membranes, a mixture of ion exchange resin particles with opposite charges and the base polymer on the surface of the ion exchange membrane A known film such as a thick film can be used.
Neoceptor BP-1 (trade name, manufactured by Tokuyama Corporation), Selemion (trade name, manufactured by Asahi Glass Co., Ltd.), and the like.

The cathode used in the present invention preferably has a low hydrogen over-electricity, a metal plate of iron, nickel, stainless steel, etc., a surface of the base material such as iron, stainless steel, etc., sulfur-containing nickel, Raney nickel alloy, nickel oxide Can be used, and can be plated with one or more of gold, platinum, palladium and the like.

As the anode used in the present invention, a metal plate made of stainless steel, titanium, gold, platinum, palladium or the like, and a surface coated with at least one of ruthenium oxide, inorganic oxide, and carbon can be used.

In the electrodialysis method according to the present invention, the acid chamber and the alkali chamber are provided with tanks of hydrochloric acid and lithium hydroxide aqueous solution to be supplied to the chambers, and the respective liquids are circulated between the liquid tanks and the chambers. Is preferred. As a method of extracting the hydrochloric acid or lithium hydroxide aqueous solution that is generated, at the beginning of operation, hydrochloric acid and lithium hydroxide aqueous solution with low concentrations are charged to produce hydrochloric acid and lithium hydroxide, and when the concentration reaches a predetermined level. Even in the so-called batch method, where a fixed amount is extracted and then replenished with distilled water or purified water to return to the initial thin concentration, a predetermined concentration of hydrochloric acid or lithium hydroxide aqueous solution is charged in advance, and it is continuously applied according to the amount of electricity applied. Alternatively, a continuous system may be used in which distilled water or purified water is added to overflow a hydrochloric acid or lithium hydroxide aqueous solution having a predetermined concentration.

Similarly, the salt solution and salt tank are also connected to the salt solution tank through a salt solution circulation line, and the salt solution discharged from the salt chamber is desalted while circulating again through the salt tank to the salt chamber. The cell voltage is measured, and when the measured voltage exceeds a preset voltage value, a new lithium chloride aqueous solution is supplied to the salt solution circulation line through the salt solution supply line.

As a method of monitoring the cell voltage, a conventionally known method is adopted. In order to detect the cell voltage, generally two or more platinum wire electrodes are inserted between two or more separated membranes, the voltage is measured under current flow, and the cell stack between the aforementioned electrodes is measured. A method of calculating by dividing by a number can be employed. By inserting platinum wire electrodes in the anode and cathode chambers, detecting the voltage between the stacks and measuring the cell voltage, the average value of the concentration of the lithium chloride aqueous solution can be obtained, and any abnormalities such as blistering can occur. It is possible to detect even when it occurs in such a film, which is preferable.

The cell voltage is usually 1 to 3 volts. When exceeding a preset cell voltage, for example, 4 to 6 volts, it means that the concentration of the lithium chloride aqueous solution in the salt chamber is lowered to an extent that is not suitable for electrodialysis. In such a case, a new lithium chloride aqueous solution is supplied to the salt aqueous solution circulation line.

The current density of the bipolar membrane electrodialysis used in the present invention is usually in the range of 1 to 50 A / dm ² , preferably 5 to 20 A / dm ² , and operates at a constant current density.
If the current density is constant, the cell voltage is hydrochloric acid, lithium chloride aqueous solution, lithium hydroxide aqueous solution concentration, flow rate of each solution, temperature, cation exchange membrane, anion exchange membrane, bipolar membrane electrical resistance, blister, It varies depending on factors such as the presence or absence of scale. If the cell voltage does not decrease even when a new lithium chloride aqueous solution is added, it is considered that blistering has occurred in the bipolar membrane or scale has occurred in the membrane in the cell. Good.

The invention's effect

According to the present invention, lithium hydroxide aqueous solution and hydrochloric acid can be produced simultaneously by bipolar membrane electrodialysis of lithium chloride aqueous solution, and hydrochloric acid is extracted from lithium-containing ore, and lithium chloride is used as a lithium resource from a lithium ion secondary battery. Can be used repeatedly to recover. One lithium hydroxide aqueous solution is removed and reduced with an ion exchange resin to sinter positive electrode active material for lithium ion secondary batteries as a high purity lithium raw material, to produce electrolyte LiPF _{6 and the} like, and It can be supplied as raw materials such as lithium niobate and lithium tantalate as SAW filter materials for electronic equipment.
In addition, it becomes possible to produce lithium hydroxide for the above-mentioned use with hydrochloric acid obtained from irrigation.

Hereinafter, the present invention will be described in detail with reference to Examples, Comparative Examples, and Reference Examples, but the scope of the present invention is not limited to these Examples. In the analysis method, each element other than lithium is measured by the ICP method. Lithium content (%) is calculated as lithium hydroxide monohydrate by correcting alkali and alkaline earth components other than lithium as determined by ICP method from alkali titration equivalent as determined by titration method. It is shown as a numerical value multiplied by an amount of 16.549%. Chlorine ions (Cl ⁻ ) and sulfate radicals (SO 4 ^{− −} ) are measured by ion chromatography.

Technical grade lithium carbonate powder is dissolved in dilute hydrochloric acid and finally evaporated to dryness.
This is dissolved in distilled water to obtain a lithium chloride aqueous solution.
The first bipolar membrane, the cation exchange membrane, the anion exchange membrane, and the second bipolar membrane are arranged in this order between the pair of anions and anodes. The first flow path formed between the anion exchanger side of the first bipolar membrane and the cation exchange membrane is used as an alkali chamber, and an aqueous lithium hydroxide solution is present to form a cation exchange membrane and an anion exchange membrane. In the presence of a lithium chloride aqueous solution using the second flow path as a salt chamber, hydrochloric acid is supplied using the third flow path formed between the anion exchange membrane and the cation exchanger of the second bipolar membrane as the acid chamber. Be present in a bipolar membrane electrodialyzer that passes a direct current between the anode and cathode.
The obtained hydrochloric acid is repeatedly used to dissolve and decompose lithium carbonate powder to form lithium chloride. Moreover, the obtained lithium hydroxide aqueous solution is subjected to a purification step for removing impurities caused by the ion exchange resin. The lithium hydroxide aqueous solution is passed through a Limber modified product column of Amberlite IRC748, a Li modified product column of Amberlite IR120B, and an Amberlite IRA410 OH column, respectively, and purified. The mixture is heated and concentrated by removing water vapor at around the boiling temperature, and the precipitate is separated and dried to obtain a lithium hydroxide monohydrate powder. The analysis results are shown in Table 1.

4 grams of carbon fine powder (Spar P) is mixed with 100 grams of spojumen (Lithia pyroxene) finely pulverized by a vibration mill in a mortar and baked at 950 ° C. for 2 hours in a nitrogen gas atmosphere.
About 5 g of this calcined product is added 100 ml of about 6N hydrochloric acid and evaporated to dryness, 50 ml of about 12N hydrochloric acid is added again and heated at 75 ° C. for 30 minutes to extract lithium as lithium chloride. The pH is adjusted with aqueous ammonia to precipitate and remove aluminum and iron.
A trace amount of iron, aluminum, calcium, magnesium, and the like are removed by the IRC748 lithium-modified chelate resin. A lithium chloride aqueous solution obtained by repeatedly treating spodumene (lithia pyroxene) to obtain the necessary amount for bipolar electrodialysis is obtained. This aqueous lithium chloride solution is used to obtain an aqueous lithium hydroxide solution and hydrochloric acid using a bipolar membrane electrodialyzer. The diluted lithium chloride aqueous solution may be concentrated and subjected to dialysis again, or may be mixed with a newly prepared lithium chloride aqueous solution.
Hydrochloric acid is separately increased to a desired concentration and repeatedly used for the extraction of the lithium content from the fired product of spodumene (lithia pyroxene).
The lithium hydroxide aqueous solution obtained by the bipolar membrane electrodialyzer is sequentially passed through a lithium-modified chelate resin of Amberlite IRC748 (manufactured by Organo), a Li-modified product column of Amberlite IR120B and an Amberlite IRA410 OH column for purification. . Heat and concentrate to separate the precipitate and dry. Table 1 shows the analysis results of the lithium hydroxide obtained in Table 1.

A used lithium ion secondary battery (cylindrical can type 1865) is immersed in an aqueous lithium chloride solution and discharged until no bubbles are generated. The can is opened, the positive electrode active material powder coated on the aluminum foil is peeled off, and the lithium content is extracted with dilute hydrochloric acid as a lithium chloride aqueous solution. Also, the electrolyte is drained with dilute hydrochloric acid to perform defluorination treatment. These lithium chloride aqueous solutions are once evaporated to dryness to recover excess hydrochloric acid.
Butyl alcohol is extracted by adding butyl alcohol to the dried solid, and butyl alcohol is removed by distillation. On the other hand, the obtained lithium chloride is dissolved in distilled water, and then applied to a bipolar membrane electrodialyzer to simultaneously add an aqueous lithium hydroxide solution and hydrochloric acid. obtain. The hydrochloric acid obtained here is repeatedly used to recover the lithium content in the used lithium ion secondary battery as lithium chloride.
The obtained lithium hydroxide aqueous solution is passed through a Limber modified product column of Amberlite IRC748, a Li modified product column of Amberlite IR120B, and an Amberlite IRA410 OH column, respectively, and purified. Heat, concentrate and remove steam near boiling temperature, separate and dry the precipitate. Table 1 shows the analysis results of the lithium hydroxide monohydrate obtained in Table 1.

Lithium chloride powder selectively adsorbed and separated from the irrigation water containing lithium salt is made into a lithium chloride aqueous solution with distilled water and subjected to bipolar membrane electrodialysis to obtain a lithium hydroxide aqueous solution while simultaneously obtaining hydrochloric acid.
The obtained lithium hydroxide aqueous solution is passed through a Limber modified product column of Amberlite IRC748, a Li modified product column of Amberlite IR120B, and an Amberlite IRA410 OH column, respectively, and purified. Heat, concentrate and remove steam near boiling temperature, separate and dry the precipitate. Table 1 shows the analysis results of the lithium hydroxide monohydrate obtained in Table 1.

Comparative Example 1

The 500 ml liquid in the cathode chamber (chamber) obtained in Example 1 was heated, concentrated, cooled to 65 ° C., separated from the deposited one, and the analysis result of the one dried under reduced pressure at room temperature is shown. It is shown in 1.

Reference example 1

Table 1 shows the results of analysis of commercially available high purity lithium hydroxide monohydrate.

Claims (5)

A salt chamber, an acid chamber and an alkali chamber are formed using a bipolar membrane, an anion exchange membrane and a cation exchange membrane between the anode and the cathode, and an aqueous solution of lithium chloride is supplied to the salt chamber to supply hydrochloric acid from the acid chamber. High-purity lithium hydroxide characterized in that hydrochloric acid is obtained by bipolar membrane electrodialysis that can respectively remove lithium hydroxide aqueous solution from the alkaline chamber, while impurities are removed or reduced by adding a purification step to the lithium hydroxide aqueous solution Manufacturing method. The method for producing high-purity lithium hydroxide according to claim 1, which is lithium chloride obtained by reacting lithium carbonate with hydrochloric acid. The method for producing high-purity lithium hydroxide according to claim 1, which is lithium chloride obtained by extraction with hydrochloric acid from a lithium-containing ore. 2. The high purity lithium hydroxide according to claim 1, which is lithium chloride obtained by recovering lithium contained in a lithium-containing electrolyte such as LiPF6 from the used lithium ion secondary battery and the positive electrode active material with hydrochloric acid. Manufacturing method. 2. The method for producing high purity lithium hydroxide according to claim 1, wherein the lithium chloride is selectively adsorbed and separated from irrigation.