HK1231142B - Methods for treating lithium-containing materials - Google Patents

Description

Method for processing lithium-containing materials

This application claims priority to US 61/943,700, filed February 24, 2014, which is incorporated herein by reference in its entirety.

The present disclosure relates to methods for extracting lithium from lithium-containing materials.

Methods for extracting lithium from lithium-containing materials are known, which include leaching an acid-roasted lithium-containing material. For example, in such methods, the lithium-containing material is roasted in the presence of an acid, such as sulfuric acid, to obtain an acid-roasted lithium-containing material, from which lithium can then be extracted.

According to aspects of the present disclosure, there is provided a method for extracting lithium from a lithium-containing material, the method comprising leaching a lithium-bisulfate-roasted lithium-containing material under conditions suitable for obtaining an aqueous composition comprising lithium compounds.

According to another aspect of the present disclosure, there is provided a method for preparing lithium hydroxide, the method comprising:

A first aqueous composition comprising lithium sulfate and/or lithium bisulfate is obtained by the method for extracting lithium from a lithium-containing material according to the method of the present disclosure; and

Under suitable conditions, the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is subjected to a membrane electrolysis process for at least partially converting the lithium sulfate and/or lithium bisulfate into lithium hydroxide.

According to another aspect of the present disclosure, there is provided a method for preparing lithium hydroxide, the method comprising:

Obtaining a first aqueous composition comprising lithium sulfate and/or lithium bisulfate by the method for extracting lithium from a lithium-containing material according to the method of the present disclosure;

subjecting the first aqueous composition comprising lithium sulfate and/or lithium bisulfate to a membrane electrolysis process under suitable conditions to at least partially convert the lithium sulfate and/or lithium bisulfate into lithium hydroxide and obtain a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and

The second aqueous composition comprising lithium sulfate and/or lithium bisulfate is used as the aqueous composition comprising lithium bisulfate in the method according to the present disclosure.

According to another aspect of the present disclosure, there is provided a method for preparing lithium hydroxide, the method comprising:

mixing a lithium-containing material with an aqueous composition comprising lithium bisulfate, and thereby obtaining a mixture;

calcining the mixture under suitable conditions to obtain a lithium bisulfate-calcined lithium-containing material;

leaching the lithium bisulfate roasted lithium-containing material under conditions suitable to obtain a first aqueous composition comprising lithium sulfate and/or lithium bisulfate;

subjecting the first aqueous composition comprising lithium sulfate and/or lithium bisulfate to a membrane electrolysis process under suitable conditions to at least partially convert the lithium sulfate and/or lithium bisulfate into lithium hydroxide and obtain a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and

The second aqueous composition containing lithium sulfate and/or lithium hydrogen sulfate is used as the aqueous composition containing lithium hydrogen sulfate for mixing with the lithium-containing material and obtaining a mixture.

It has been found that by using the methods of the present disclosure, it is possible to replace sulfuric acid with lithium bisulfate. It has also been found that, for example, it is possible to reduce the costs associated with using an acid reagent, namely sulfuric acid. In fact, in certain circumstances, it is possible to recycle the lithium bisulfate obtained in a membrane electrolysis process (e.g., by partially converting lithium sulfate into lithium hydroxide) to extract lithium from a lithium-containing material. It has been found that by using the methods of the present disclosure, it is possible to easily recover sulfuric acid in the form of an acidic composition that can be used to treat the lithium-containing material and/or to recover lithium sulfate from a second aqueous composition and reuse it in a membrane electrolysis process. For example, by using such methods, lithium sulfate _monohydrate ( _Li2SO4 · _H2O ) can be substantially selectively precipitated and thus easily recovered and reused.

According to another aspect of the present disclosure, there is provided a method for preparing lithium hydroxide, the method comprising: subjecting a first aqueous composition comprising lithium sulfate to a membrane electrolysis process under suitable conditions to at least partially convert the lithium sulfate into lithium hydroxide and obtain a second aqueous composition comprising lithium sulfate;

optionally increasing the concentration of the acid in the second aqueous composition; and

A second aqueous composition comprising lithium sulfate is used for mixing with the lithium-containing material.

According to another aspect of the present disclosure, there is provided a method for preparing lithium hydroxide, the method comprising:

mixing a lithium-containing material with an acidic aqueous composition optionally comprising lithium sulfate, and thereby obtaining a mixture;

calcining the mixture under suitable conditions to obtain a calcined lithium-containing material;

leaching the roasted material under conditions suitable to obtain a first aqueous composition comprising lithium sulfate;

subjecting the first aqueous composition comprising lithium sulfate to a membrane electrolysis process under suitable conditions for at least partially converting the lithium sulfate into lithium hydroxide and obtaining a second aqueous composition comprising lithium sulfate; and

optionally increasing the concentration of the acid in the second aqueous composition; and

The second aqueous composition comprising lithium sulfate is used as the acidic aqueous composition, optionally comprising lithium sulfate, for mixing with the lithium-containing material and obtaining a mixture.

According to another aspect of the present disclosure, there is provided a method for preparing lithium hydroxide, the method comprising: subjecting a first aqueous composition comprising lithium sulfate to a membrane electrolysis process under suitable conditions to at least partially convert the lithium sulfate into lithium hydroxide, and obtaining a second aqueous composition comprising lithium sulfate; and

optionally increasing the concentration of the acid in the second aqueous composition; and

The lithium sulfate is recovered from the second aqueous composition and reused in the membrane electrolysis process.

It has been discovered that by using the methods of the present disclosure, it is possible to readily recover sulfuric acid in the form of an acidic composition that can be used to treat lithium-containing materials and/or to recover lithium sulfate from a second aqueous composition and reuse it in a membrane electrolysis process. For example, by using such methods, lithium sulfate _monohydrate ( _Li2SO4 · _H2O ) can be substantially selectively precipitated and thus readily recovered and reused.

According to another aspect of the present disclosure, a method is provided for treating an aqueous composition comprising lithium sulfate for a membrane electrolysis process, the process comprising removing water from the aqueous composition for the membrane electrolysis process under conditions suitable for substantially selectively precipitating lithium sulfate monohydrate.

According to another aspect of the present disclosure, there is provided a method for extracting alkali from an alkali-containing material, the method comprising leaching an alkaline bisulfate-roasted alkali-containing material under conditions suitable for obtaining an aqueous composition comprising an alkaline compound.

In the following drawings, various embodiments of the present disclosure are shown by way of example only:

FIG1 is a schematic diagram of a method according to an embodiment of the present disclosure;

Figures 2 and 3 are graphs showing the cumulative current efficiency for alkali hydroxide production as a function of the amount of conductivity;

FIG4 is a schematic diagram of a method according to another embodiment of the present disclosure;

Figures 5 and 6 are XRD analyses of the precipitated crystals recovered from the separation step; and

7 is a graph of lithium sulfate recovery in a separation step on a mass basis as a function of water removed at atmospheric pressure.

Unless otherwise indicated, the definitions and examples described herein are intended to apply to all embodiments and aspects of the disclosure described herein to which they apply, as will be understood by those skilled in the art.

As used in this disclosure, the singular forms "a," "an," and "the" include plural references unless the context clearly indicates otherwise. For example, an embodiment including "a lithium-containing material" should be understood to present certain aspects having one lithium-containing material, or two or more additional lithium-containing materials.

In embodiments comprising an "additional" or "second" component, such as an additional or second lithium-containing material, the second component, as used herein, is different from the other components or the first component. A "third" component is different from the other, first and second components, and further enumerated and "additional" components are likewise different.

In the understanding of the scope of the present disclosure, the terms "comprising" and their derivatives as used herein are intended to be open-ended terms, which specify the presence of specified features, elements, components, groups, integers and/or steps, but do not exclude the presence of other unspecified features, elements, components, groups, integers and/or steps. The above also applies to words with similar meanings such as the terms "including", "having" and their derivatives. The terms "consisting of" and their derivatives as used herein are intended to be closed-ended terms, which specify the presence of specified features, elements, components, groups, integers and/or steps, but exclude the presence of other unspecified features, elements, components, groups, integers and/or steps. The term "consisting essentially of" as used herein is intended to specify the presence of specified features, elements, components, groups, integers, and/or steps as well as basic features and new features that do not substantially affect the features, elements, components, groups, integers and/or steps.

As used herein, terms of degree, such as "about" and "approximately," mean a reasonable amount of deviation of the modified term so that the target structure is not significantly altered. These terms of degree should be interpreted as including a deviation of at least ±5% or at least ±10% of the modified term if the deviation would not negate the meaning of the modified term.

The term "suitable" as used herein means that the specific conditions selected will depend on the specific manipulation or operation to be performed, but the selection will be within the skill of those skilled in the art. All methods described herein should be carried out under conditions sufficient to provide the desired product. It will be understood by those skilled in the art that, when applicable, all reaction conditions may be varied, including, for example, reaction time, reaction temperature, reaction pressure, reactant ratio, flow rate, reactant purity, current density, voltage, electrode material, concentration, H, redox potential, unit area, the type of membrane use, and recirculation rate to optimize the yield of the desired product, and that it is within their skill to accomplish this variation.

As used herein, the term "membrane electrolysis process" refers to a process that utilizes, for example, an ion exchange membrane and a potential difference as the driving force for ionic species. The membrane electrolysis process can be, for example, (membrane) electrodialysis or (membrane) electrolysis. For example, the membrane electrolysis process can be membrane electrolysis.

As used herein, the expression "at least substantially maintain" when referring to maintaining a value of pH or a pH range during a process of the present disclosure or a portion thereof (e.g., a membrane electrolysis process) means that the pH or pH range is maintained at a value of at least 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% of the time during the process or portion thereof.

As used herein, the expression "at least substantially maintain" when referring to maintaining a voltage or voltage range of value during a method of the present disclosure or a portion thereof (e.g., a membrane electrolysis process) means that the voltage or voltage range of value is maintained at least 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% of the time during the method or portion thereof.

As used herein, the expression "at least substantially maintain" when referring to maintaining a value of the current efficiency or current efficiency range during a method of the present disclosure or a portion thereof (e.g., a membrane electrolysis process) means that the current efficiency or current efficiency range is maintained at a value of at least 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% of the time during the method or portion thereof.

As used herein, the expression "at least substantially maintain" when referring to maintaining a concentration or concentration range of value during a process of the present disclosure or a portion thereof (e.g., a membrane electrolysis process) means that the concentration or concentration range of value is maintained at least 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% of the time during the process or portion thereof.

As used herein, the expression "at least substantially maintain" when referring to maintaining a temperature or temperature range of value during a method of the present disclosure or a portion thereof (e.g., a membrane electrolysis process) means that the temperature or temperature range of value is maintained at least 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% of the time during the method or portion thereof.

An exemplary flow chart of the method of the present disclosure is shown in FIG1 . The method 10 exemplified therein is for producing lithium hydroxide. Referring to FIG1 , in the method exemplified therein, a lithium-containing material 12 (e.g., a lithium-containing ore such as β-spodumene) can be mixed with an aqueous composition comprising lithium bisulfate and/or lithium sulfate to obtain a mixture. In a roasting and leaching step 14 , the mixture can then be roasted under suitable conditions to obtain a lithium bisulfate roasted lithium-containing material and/or a roasted lithium-containing material, which can then be leached under conditions suitable for obtaining a first aqueous composition 16 comprising lithium sulfate and/or lithium bisulfate (e.g., a first aqueous composition comprising lithium sulfate). The first aqueous composition 16 containing lithium sulfate and/or lithium bisulfate can then be purified 18, for example to remove at least a portion of metallic or non-metallic impurities (e.g., Si and its derivatives) that have been incorporated into the first aqueous composition, and then subjected to a membrane electrolysis process 20 (e.g., a two-chamber monopolar or bipolar membrane electrolysis process, a three-chamber monopolar or bipolar membrane electrolysis process, or a combination of a two-chamber monopolar or bipolar membrane electrolysis process and a three-chamber monopolar or bipolar membrane electrolysis process) under suitable conditions to at least partially convert the lithium sulfate and/or lithium bisulfate into lithium hydroxide 22 and obtain a second aqueous composition 24 containing lithium sulfate and/or lithium bisulfate. The second aqueous composition 24 containing lithium sulfate and/or lithium bisulfate can then be used as an aqueous composition containing lithium bisulfate for mixing with a lithium-containing material 12 (e.g., a lithium-containing ore such as β-spodumene) to obtain a mixture. As can be seen from FIG. 1 , some additional H ₂ SO ₄ can be added. For example, H ₂ SO ₄ can be added to the second composition. For example, when the second composition is used as a source of acid and lithium bisulfate, _H2SO4 may be _added just prior to calcination.

For example, purification 18 can be performed as described in PCT application WO 2013/159194, entitled "Process for the Preparation of Lithium Hydroxide," the contents of which are incorporated by reference.

Another exemplary flow chart of the method of the present disclosure is shown in FIG4 . The method 110 illustrated therein is for preparing lithium hydroxide and is similar to the method 10 illustrated in FIG1 . Some steps (112, 114, 116, 118, 120, 122, and 124) in the method of FIG4 are similar to some steps present in the method of FIG1 (12, 14, 16, 18, 20, 22, and 24). The contents of the first composition (see 16 and 116) and the second composition (see 24 and 124) may optionally be slightly modified. For example, in step 116, the first composition obtained comprises lithium sulfate and, optionally, lithium bisulfate. Furthermore, the second composition obtained in step 124 comprises lithium sulfate and, optionally, lithium bisulfate. Aside from such characteristics of the contents of the first and second compositions and the fact that steps 126, 128, and 130 are not identical to the method of FIG1 , the two methods are completely similar. Regarding separation step 126, it was discovered that this step is optional, instead of simply reusing the second composition for calcination step 114 (see the dashed line between steps 124 and 114). In separation step 126, water is removed to obtain a more concentrated acidic composition 130. It was discovered that this more concentrated acidic composition, comprising sulfuric acid, is capable of undergoing the calcination step 114. Those skilled in the art will appreciate that various methods can be used to remove water from the second composition in step 126. For example, the second composition can be heated or subjected to a membrane or column dehydration process. The second composition can also be cooled to facilitate precipitation of lithium sulfate and then subjected to solid/liquid separation to recover lithium sulfate 128. The second composition can also be seeded with lithium sulfate to utilize the precipitation of lithium sulfate 128. Thus, there are many possible methods for implementing steps 126, 128, _and 130. As can be seen in FIG4, some additional _H2SO4 can be added. For example, _H2SO4 can be _added only before or after separation step 26 is performed. For example, when using the acidic composition 130 as the acid source, H ₂ SO ₄ may be added just before performing the roasting 114 .

For example, in separation step 126, the second composition can be heated at a temperature of about 100°C to about 135°C or about 100°C to about 125°C to remove water therefrom. The separation step can be performed by distillation, which can be performed at atmospheric pressure or under vacuum. It has been observed that during this process, it is possible to concentrate the sulfuric acid and obtain an acidic composition 130 that can ultimately be used for roasting 114. Furthermore, while the second composition is heated, it has been observed that substantially selective precipitation of _lithium sulfate monohydrate ( _Li2SO4.H2O ) occurs. It is also noted that when the temperature is maintained below about 125°C or 130°C, the formation _of anhydrous lithium sulfate is avoided. Solid/liquid separation is then performed, and the precipitated lithium sulfate, for example, as ( _Li2SO4.H2O ), can be recovered in step _128. The latter has been found to be more crystalline than anhydrous lithium sulfate. In fact, the monohydrate is easier to recover due to _its needle-like crystal shape and less tendency to retain water and/or acid. When the solid is lithium sulfate monohydrate, the solid-liquid separation step is significantly easier to perform (compared to anhydrous lithium sulfate). Therefore, the recovered lithium sulfate can be reused in the membrane electrolysis process 120.

The examples presented below are non-limiting and serve to better illustrate the methods of the present disclosure.

The present disclosure includes a method for extracting lithium from a lithium-bearing material, the method comprising leaching a lithium-bisulfate-roasted lithium-bearing material under conditions suitable for obtaining an aqueous composition comprising lithium compounds.

For example, a lithium-bisulfate-calcined lithium-containing material can be prepared by a method comprising:

mixing a lithium-containing material with an aqueous composition comprising lithium bisulfate, and thereby obtaining a mixture; and

The mixture is calcined under suitable conditions to obtain a lithium bisulfate-calcined lithium-containing material.

For example, a lithium-bisulfate-roasted lithium-containing material can be prepared using known methods for calcining lithium-containing materials. Suitable conditions can be selected by those skilled in the art, based on their common knowledge and in light of this disclosure, to obtain a lithium-bisulfate-roasted lithium-containing material. For example, a method comprising acid-roasting a lithium-containing material is disclosed in PCT application WO 2013/159194, entitled "Method for Preparing Lithium Hydroxide," the contents of which are incorporated by reference.

For example, the calcined lithium-containing material can be prepared using known methods for calcining lithium-containing materials. Suitable conditions can be selected by those skilled in the art, based on their common knowledge and in light of this disclosure, to obtain the calcined lithium-containing material. For example, a method comprising calcining a lithium-containing material with an acid is disclosed in PCT application WO 2013/159194, entitled "Method for Preparing Lithium Hydroxide," the contents of which are incorporated by reference.

For example, the molar ratio between the lithium bisulfate in the aqueous composition comprising lithium bisulfate and the lithium in the lithium-containing material can be about 0.1:1 to about 10:1, about 0.1:1 to about 4:1, about 0.2:1 to about 4:1, about 0.5:1 to about 4:1, about 1:1 to about 2:1, or about 1:1.

For example, the molar ratio between lithium sulfate in the aqueous composition comprising lithium sulfate and lithium in the lithium-containing material can be about 0.1:1 to about 10:1, about 0.1:1 to about 4:1, about 0.2:1 to about 4:1, about 0.5:1 to about 4:1; about 1:1 to about 2:1, or about 1:1.

For example, an aqueous composition comprising lithium bisulfate may further comprise an acid such as, for example, sulfuric acid.

For example, an aqueous composition comprising lithium sulfate may further comprise an acid such as, for example, sulfuric acid.

For example, the acid may be sulfuric acid.

For example, the molar ratio between the acid in the aqueous composition comprising lithium bisulfate and the lithium in the lithium-containing material can be about 0.5:1 to about 4:1, about 1:1 to about 2:1, or about 1.1:1 to about 1.25:1.

For example, the molar ratio between the acid in the aqueous composition comprising lithium sulfate and the lithium in the lithium-containing material can be about 0.5:1 to about 4:1, about 1:1 to about 2:1, or about 1.1:1 to about 1.25:1.

For example, the acid may be present in a stoichiometric excess of about 1% to about 100% based on the amount of lithium in the lithium-containing material.

For example, the acid may be present in a stoichiometric excess of about 30% to about 100% based on the amount of lithium in the lithium-containing material.

For example, the acid may be present in a stoichiometric excess of about 20% to about 50% based on the amount of lithium in the lithium-containing material.

For example, the acid may be present in a stoichiometric excess of about 10% to about 50% based on the amount of lithium in the lithium-containing material.

For example, the acid may be present in a stoichiometric excess of about 20% to about 45% based on the amount of lithium in the lithium-containing material.

For example, the acid may be present in a stoichiometric excess of about 10% to about 30% based on the amount of lithium in the lithium-containing material.

For example, the acid may be present in a stoichiometric excess of about 55% to about 60% based on the amount of lithium in the lithium-containing material.

For example, the first aqueous composition may comprise potassium and/or sodium.

For example, the second aqueous composition may comprise potassium and/or sodium.

For example, the second aqueous composition may contain fewer Li ⁺ ions than HSO ₄ ⁻ ions.

For example, the second aqueous composition may comprise free H ₂ SO ₄ .

For example, the second aqueous composition may comprise free _{H 2} SO _{4 that} is produced during the membrane electrolysis process.

For example, the second composition may include lithium bisulfate and sulfuric acid.

For example, the second composition may include lithium sulfate and sulfuric acid.

For example, the second composition may include lithium bisulfate, lithium sulfate, and sulfuric acid.

For example, the second composition may include sulfuric acid.

For example, the mixture can be calcined at a calcination temperature of about 150° C. to about 400° C. For example, the mixture can be calcined at a calcination temperature of about 200° C. to about 350° C., about 200° C. to about 325° C., about 200° C. to about 300° C., about 250° C. to about 350° C., or about 250° C. to about 300° C. For example, the mixture can be calcined at a calcination temperature of about 250° C. or about 300° C.

For example, the mixture can be roasted at the roasting temperature for about 1 minute to about 24 hours. For example, the mixture can be roasted at the roasting temperature for about 1 minute to about 2 hours. For example, the mixture can be roasted at the roasting temperature for about 15 minutes to about 2 hours. For example, the mixture can be roasted at the roasting temperature for about 30 minutes.

For example, lithium sulfate monohydrate may be substantially selectively precipitated and/or substantially selectively formed from the second composition.

For example, anhydrous lithium sulfate can be substantially selectively precipitated and/or substantially selectively formed from the second composition.

For example, the method may further include recovering lithium sulfate from the second aqueous composition and reusing the lithium sulfate in the membrane electrolysis process.

For example, the method may further include at least partially recovering lithium sulfate from the second aqueous composition before using the second aqueous composition for reacting with the lithium-containing material, and reusing the lithium sulfate in the membrane electrolysis process.

For example, the method can include increasing the concentration of the acid in the second aqueous composition by removing water from the second aqueous composition.

For example, the acid concentration can be increased by heating the second aqueous composition.

For example, the acid concentration can be increased by heating the aqueous composition.

For example, the concentration of the acid in the second aqueous composition may be increased by adding some more concentrated acid or some acid having a higher concentration.

For example, the concentration of the acid in the second aqueous composition can be increased by adding some more concentrated acid or some acid having a higher concentration.

For example, the concentration of the acid in the acidic composition can be increased by adding some more concentrated acid or some acid having a higher concentration.

For example, the second aqueous composition can be heated at a temperature of about 100°C to about 135°C, about 100°C to about 300°C, about 100°C to about 250°C, about 200°C to about 250°C, about 105°C to about 130°C, about 110°C to about 130°C, about 115°C to about 125°C, about 100°C to about 125°C.

For example, the acidic composition can be heated at a temperature of about 100°C to about 135°C, about 100°C to about 300°C, about 100°C to about 250°C, about 200°C to about 250°C, about 105°C to about 130°C, about 110°C to about 130°C, about 115°C to about 125°C, about 100°C to about 125°C.

For example, water can be removed by heating the membrane electrolysis process aqueous composition at the temperatures discussed above.

For example, the second aqueous composition can be heated at atmospheric pressure.

For example, the aqueous composition may be heated at atmospheric pressure.

For example, the acid concentration can be increased by membrane dehydration.

For example, the acid concentration can be increased by reverse osmosis membrane methods.

For example, wherein removing water from the aqueous composition may cause precipitation of lithium sulfate monohydrate.

For example, removing water from an aqueous composition can result in substantially selective precipitation of lithium sulfate monohydrate.

For example, removing water from an aqueous composition can cause crystallization of lithium sulfate monohydrate.

For example, the method can include increasing the concentration of the acid in the aqueous composition by removing water from the aqueous composition, thereby substantially selectively precipitating lithium sulfate.

For example, wherein removing water from the second aqueous composition can cause precipitation of lithium sulfate monohydrate.

For example, removing water from the second aqueous composition can result in substantially selective precipitation of lithium sulfate monohydrate.

For example, removing water from the second aqueous composition can cause crystallization of lithium sulfate monohydrate.

For example, the method can include increasing the concentration of the acid in the second aqueous composition by removing water from the second aqueous composition, thereby substantially selectively precipitating lithium sulfate.

For example, the method may further include performing solid-liquid separation to recover lithium sulfate, thereby obtaining lithium sulfate and an acidic composition.

For example, the solid-liquid separation can be performed at a temperature of about 5°C to about 150°C, about 15°C to about 130°C, about 20°C to about 125°C, about 25°C to about 125°C, about 20°C to about 75°C, about 20°C to about 50°C, or about 50°C to about 100°C.

For example, the method may further include performing solid-liquid separation to recover lithium sulfate, thereby obtaining lithium sulfate and acidic water effective for mixing with the lithium-containing material.

For example, the method includes recovering lithium sulfate in the form of lithium sulfate monohydrate from the second aqueous composition and reusing the lithium sulfate in the membrane electrolysis process.

For example, the acid may be H ₂ SO ₄ .

For example, the method may include performing solid-liquid separation to recover lithium sulfate, thereby obtaining lithium sulfate and an acidic aqueous solution effective for mixing with a lithium-containing material.

For example, the method may further comprise reusing the obtained lithium sulfate in the membrane electrolysis process.

For example, the second composition can be further treated to increase the acid concentration. For example, such treatment to increase the acid concentration can be performed by dehydration membranes, reverse osmosis membranes, heating, or any other suitable method known in the art. For example, the acidic composition can be treated to remove at least 75%, at least 80%, at least 85%, at least 90%, or at least 95% of the water.

For example, the acidic composition can be further treated to increase the acid concentration. For example, such treatment can be performed by a dehydration membrane process, a reverse osmosis membrane process, heating, or any other known suitable method to increase the acid concentration. For example, the acidic composition can be treated to remove at least 75%, at least 80%, at least 85%, at least 90%, or at least 95% of the water.

For example, once the second composition is obtained, and before completing the cycle and performing a further firing, _some fresh _H2SO4 may be added.

For example, once the second composition is obtained and before completing the cycle and performing another acid roasting, some fresh and concentrated _{H2SO4 can} be _added . For example, such concentrated _H2SO4 can be about 90% to about 98%, about 93% to about 98%, or about 95% to about 98%.

For example, at least 70 weight percent of the water contained in the second composition can be removed therefrom, and about 30 weight percent to about 80 weight percent of the lithium sulfate can be removed from the second composition by crystallization.

The lithium-containing material can be different, and a suitable lithium-containing material can be selected by a person skilled in the art. For example, the lithium-containing material can be a lithium-containing ore, a lithium-containing compound, or a regenerated industrial lithium-containing entity.

For example, the lithium-containing ore can comprise, consist essentially of, or consist of α-spodumene, β-spodumene, lepidolite, pegmatite, petalite, eucryptite, hectorite, montmorillonite, jaddarite, clay, or a mixture thereof. For example, the lithium-containing ore can comprise, consist essentially of, or consist of β-spodumene or jaddarite. For example, the lithium-containing ore can comprise, consist essentially of, or consist of β-spodumene or jaddarite. For example, the lithium-containing ore can comprise, consist essentially of, or consist of β-spodumene.

For example, the lithium-containing compound can comprise, consist essentially of, or consist of lithium chloride, lithium sulfate, lithium bicarbonate, lithium carbonate, lithium nitrate, lithium acetate, lithium fluoride, lithium stearate, lithium citrate, or mixtures thereof.

For example, the recycled industrial lithium-containing entity may be a lithium-containing battery, other lithium product, or a derivative thereof.

The conditions for obtaining an aqueous composition comprising a lithium compound may vary, and suitable conditions may be selected by a person skilled in the art based on their common knowledge and in light of this disclosure. For example, a method comprising leaching an acid-roasted lithium-containing material is disclosed in PCT application WO 2013/159194, entitled "Process for the Preparation of Lithium Hydroxide," the contents of which are incorporated by reference.

For example, in the methods of the present disclosure, a lithium-containing material calcined with lithium bisulfate may be leached with water to obtain an aqueous composition comprising a lithium compound.

For example, calcination and leaching can be performed in a single apparatus. For example, calcination can be performed in a first apparatus and leaching can be performed in a second apparatus. Those skilled in the art will appreciate that using a first apparatus for calcination and a second apparatus for leaching can, for example, result in effective control of the concentration of the aqueous composition containing the lithium compound. The lithium-containing material can be mixed with the aqueous composition containing lithium bisulfate in the first apparatus or in another apparatus.

Those skilled in the art will appreciate that impurities may be present in lithium-containing materials, which may be leached, for example, in the methods of extracting lithium from lithium-containing materials disclosed herein, under conditions suitable for obtaining an aqueous composition comprising a lithium compound. Therefore, the method of extracting lithium from a lithium-containing material may further comprise purifying the aqueous composition comprising a lithium compound obtained from the method. Suitable purification conditions may be selected by those skilled in the art based on their common general knowledge and with reference to the present disclosure. For example, a method comprising purifying an aqueous composition comprising a lithium compound is disclosed in PCT application WO 2013/159194 entitled “Method for the Preparation of Lithium Hydroxide,” the contents of which are incorporated by reference.

For example, in the methods of extracting lithium from lithium-containing materials of the present disclosure, the lithium-containing material may further contain leachable metallic or non-metallic impurities, and the aqueous composition containing the lithium compound may be further treated under conditions suitable for removing at least a portion of the leachable metallic impurities from the aqueous composition containing the lithium compound. As used herein, the term "leachable metallic impurities" refers to metals other than lithium that may be present in the lithium-containing material and that may be co-leached with lithium in the methods of the present disclosure under conditions suitable for obtaining the aqueous composition containing the lithium compound.

As used herein, the term "leachable non-metallic impurities" refers to non-metallic compounds that are present in the lithium-containing material and that can be co-leached with lithium in the methods of the present disclosure under conditions suitable for obtaining an aqueous composition comprising lithium compounds.

For example, leachable metallic impurities may include aluminum, iron, magnesium, calcium, chromium, zinc and manganese, or mixtures thereof, which may be co-leached, for example, with lithium under conditions suitable for obtaining an aqueous composition comprising a lithium compound to obtain an aqueous composition further comprising metal ions selected from the group consisting of Al ³⁺ , Fe ²⁺ , Fe ³⁺ , Mg ²⁺ , Ca ²⁺ , Cr ²⁺ , Cr ³⁺ , Cr ⁶⁺ , Mn ²⁺ and mixtures thereof.

For example, the term "leachable non-metallic impurities" may include metalloids such as silicon or silicon dioxide.

For example, the aqueous composition comprising a lithium compound may be an aqueous composition comprising lithium sulfate and/or lithium hydrogen sulfate.For example, the aqueous composition comprising a lithium compound may be an aqueous composition comprising lithium sulfate.

For example, the molar ratio between lithium sulfate and lithium bisulfate in the aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least about 9:1.

For example, the molar ratio between lithium sulfate and lithium bisulfate in the aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least about 19:1.

For example, the molar ratio between lithium sulfate and lithium bisulfate in the aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least about 99:1.

The present disclosure also includes a method for preparing lithium hydroxide, the method comprising:

A first aqueous composition comprising lithium sulfate and/or lithium bisulfate is obtained by the method for extracting lithium from a lithium-containing material according to the method of the present disclosure; and

Under suitable conditions, the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is subjected to a membrane electrolysis process for at least partially converting the lithium sulfate and/or lithium bisulfate into lithium hydroxide.

The conditions for at least partially converting lithium sulfate and/or lithium bisulfate into lithium hydroxide can vary, and suitable conditions can be selected by those skilled in the art based on their common knowledge and in light of this disclosure. For example, methods for preparing lithium hydroxide comprising subjecting a composition comprising a lithium compound to a membrane electrolysis process are disclosed in PCT application WO 2014/138933, entitled “Method for Preparing Lithium Hydroxide”; International Patent Application No. PCT/CA2014/000769, filed on October 23, 2014, entitled “Method and System for Preparing Lithium Hydroxide”; and PCT application WO 2013/159194, entitled “Method for Preparing Lithium Hydroxide,” the contents of each of which are incorporated by reference.

For example, during the membrane electrolysis process, the pH of the lithium sulfate and/or lithium bisulfate composition can be acidic. Suitable acidic conditions can be selected by those skilled in the art based on their common knowledge and in reference to this disclosure. For example, a method for preparing lithium hydroxide comprising subjecting a composition comprising a lithium compound to a membrane electrolysis process under acidic conditions is disclosed in PCT application WO 2014/138933, entitled “Method for Preparing Lithium Hydroxide,” and International Patent Application No. PCT/CA2014/000769, filed on October 23, 2014, entitled “Method and System for Preparing Lithium Hydroxide,” the contents of each of which are incorporated by reference.

For example, the membrane electrolysis process may include a three-chamber monopolar or bipolar membrane electrolysis process, and the pH may be at least substantially maintained at about 2 to about 4 during the three-chamber monopolar or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a three-chamber monopolar or bipolar membrane electrolysis process, and the pH may be at least substantially maintained at a value of about 2 or about 1 during the three-chamber monopolar or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a two-chamber monopolar or bipolar membrane electrolysis process, and the conversion of lithium sulfate and/or lithium bisulfate to lithium hydroxide may be performed until the pH of the lithium sulfate and/or lithium bisulfate composition is about 0.1 to about 2.0, about 0.2 to about 1.5, or about 0.4 to about 1.0.

For example, the membrane electrolysis process may include a two-chamber monopolar or bipolar membrane electrolysis process, and the conversion of lithium sulfate and/or lithium bisulfate to lithium hydroxide may be performed until the pH of the lithium sulfate and/or lithium bisulfate composition is about 0.5 to about 0.7.

For example, during the membrane electrolysis process, the pH of the lithium sulfate and/or lithium bisulfate composition can be alkaline. Suitable alkaline conditions can be selected by those skilled in the art based on their common knowledge and in light of this disclosure. For example, a method for preparing lithium hydroxide comprising subjecting a composition comprising a lithium compound to a membrane electrolysis process under alkaline conditions is disclosed in PCT application WO 2013/159194, entitled "Method for Preparing Lithium Hydroxide," the contents of which are incorporated by reference.

For example, the membrane electrolysis process may include a three-chamber monostage or bipolar membrane electrolysis process, and the pH of the feed composition may be at least about 10 to about 12 during the three-chamber monostage or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a three-chamber monopolar or bipolar membrane electrolysis process, and the pH may be at least substantially maintained at about 10 to about 12 during the three-chamber monopolar or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a three-chamber monopolar or bipolar membrane electrolysis process, and the pH may be at least substantially maintained at about 10.5 to about 12.5 during the three-chamber monopolar or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a three-chamber monopolar or bipolar membrane electrolysis process, and the pH may be at least substantially maintained at about 11 to about 12 during the three-chamber monopolar or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a two-chamber single-stage or bipolar membrane electrolysis process; a three-chamber single-stage or bipolar membrane electrolysis process; a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. For example, the membrane electrolysis process may include a two-chamber single-stage or bipolar membrane electrolysis process. For example, the membrane electrolysis process may include a three-chamber single-stage or bipolar membrane electrolysis process. For example, the membrane electrolysis process may include a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. A suitable membrane electrolysis process can be selected by those skilled in the art based on their common knowledge and with reference to the present disclosure.

For example, methods for preparing lithium hydroxide comprising subjecting a composition comprising a lithium compound to a three-compartment monopolar or bipolar membrane electrolysis process are disclosed in PCT application WO 2014/138933 entitled “Method for Preparing Lithium Hydroxide” and PCT application WO 2013/159194 entitled “Method for Preparing Lithium Hydroxide,” the contents of each of which are incorporated by reference.

For example, a method for preparing lithium hydroxide comprising subjecting a composition comprising a lithium compound to a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process is disclosed in International Patent Application No. PCT/CA2014/000769, entitled “Method and System for Preparing Lithium Hydroxide,” filed on October 23, 2014, the contents of which are incorporated by reference.

Therefore, the present application also includes a method for preparing lithium hydroxide further comprising:

Under suitable conditions, subjecting the first aqueous composition comprising lithium sulfate and/or lithium bisulfate to a membrane electrolysis process, such as a two-chamber single-stage or bipolar membrane electrolysis process, to obtain a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and

The second aqueous composition containing lithium sulfate and/or lithium bisulfate is used as the aqueous composition containing lithium bisulfate in the method for preparing a lithium bisulfate-calcined lithium-containing material of the present application.

For example, the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least about 3:2.

For example, the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least about 9:1.

For example, the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least about 19:1.

For example, the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least about 99:1.

For example, the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate may be from about 3:2 to about 99:1.

For example, the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate may be about 3:2 to about 19:1.

For example, the second aqueous composition comprising lithium sulfate and/or lithium bisulfate may comprise lithium bisulfate, and the method may further comprise adding a base to a portion of the second aqueous composition comprising lithium sulfate and/or lithium bisulfate under conditions suitable for converting at least a portion of the lithium bisulfate into lithium sulfate. Those skilled in the art will understand that if there is an excess of lithium bisulfate in the method, then bleeding a portion of the second aqueous composition comprising lithium bisulfate and, optionally, lithium sulfate, from the circulation of the method of the present disclosure and adding a base to convert at least a portion of the lithium bisulfate into lithium sulfate can, for example, allow for re-equilibration of the stored solution. Suitable conditions for converting at least a portion of the lithium bisulfate into lithium sulfate can be selected by those skilled in the art. For example, the base may comprise calcium hydroxide, calcium oxide, and/or calcium carbonate.

For example, in the method of the present disclosure, calcium sulfate can also be obtained. For example, lithium bisulfate can be converted into calcium sulfate precipitate, which can finally be purified by filtering.

For example, the membrane electrolysis process may include a two-chamber unipolar or bipolar membrane electrolysis process, and during the two-chamber unipolar or bipolar membrane electrolysis process, the voltage may be at least substantially maintained at about 4V to about 5V, about 3V to about 6V, about 2V to about 8V, or about 2.5V to about 4V.

For example, the membrane electrolysis process may include a two-chamber unipolar or bipolar membrane electrolysis process, and the voltage may be at least substantially maintained at about 4.5 V during the two-chamber unipolar or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a two-chamber monostage or bipolar membrane electrolysis process, and the current efficiency of LiOH may be at least substantially maintained at about 30% to about 50%, about 30% to about 40%, 50% to about 95%, about 55% to about 90%, or about 65% to about 85% during the two-chamber monostage or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a two-chamber monopolar or bipolar membrane electrolysis process, and the current efficiency of LiOH may be at least substantially maintained at about 75% during the two-chamber monopolar or bipolar membrane electrolysis process.

For example, the lithium concentration in the first aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least substantially maintained at a range from about 20 g lithium per liter of solution to about 40 g lithium per liter of solution, from about 10 g lithium per liter of solution to about 20 g lithium per liter of solution, from about 5 g lithium per liter of solution to about 40 g lithium per liter of solution, or from about 12 g lithium per liter of solution to about 18 g lithium per liter of solution.

For example, the lithium concentration in the first aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least substantially maintained at about 30 g lithium per liter of solution to about 33 g lithium per liter of solution.

For example, the lithium concentration in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least substantially maintained at about 10 g lithium per liter of solution to about 20 g lithium per liter of solution or about 20 g lithium per liter of solution to about 40 g lithium per liter of solution.

For example, the lithium concentration in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate can be at least substantially maintained at about 30 g lithium per liter of solution to about 33 g lithium per liter of solution.

For example, the membrane electrolysis process may include a two-chamber monostage or bipolar membrane electrolysis process, and lithium hydroxide may be produced in an aqueous solution that at least substantially maintains a lithium hydroxide concentration of about 2 M to about 7 M, about 2 M to about 4 M, about 1.5 M to about 4.5 M, about 1.5 M to about 7 M, or about 2.5 M to about 3.5 M during the two-chamber monostage or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a two-chamber monopolar or bipolar membrane electrolysis process, and lithium hydroxide may be produced in an aqueous solution that at least substantially maintains a lithium hydroxide concentration of about 3.0 M during the two-chamber monopolar or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a two-chamber monostage or bipolar membrane electrolysis process, and lithium hydroxide may be produced in an aqueous solution at a temperature at least substantially maintained at about 40°C to about 100°C, or about 60°C to about 100°C, or about 75°C to about 95°C during the two-chamber monostage or bipolar membrane electrolysis process.

For example, the membrane electrolysis process may include a two-chamber monopolar or bipolar membrane electrolysis process, and lithium hydroxide may be produced in an aqueous solution having a temperature at least substantially maintained at about 80° C. during the two-chamber monopolar or bipolar membrane electrolysis process.

The method of the present disclosure can be operated, for example, as a batch method. Alternatively, the method of the present disclosure can be operated as a semi-continuous method or a continuous method.

For example, under appropriate conditions, a first aqueous composition containing lithium sulfate and/or lithium bisulfate can be subjected to a two-chamber single-stage or bipolar membrane electrolysis process to obtain a second aqueous composition containing lithium sulfate and/or lithium bisulfate; the second aqueous composition containing lithium sulfate and/or lithium bisulfate can then be used, for example, in the method for preparing a lithium-containing material roasted with lithium bisulfate of the present application; the lithium-containing material roasted with lithium bisulfate thus obtained can then be used, for example, in the method for extracting lithium from a lithium-containing material of the present application to obtain a third aqueous composition containing lithium sulfate and/or lithium bisulfate, which can then be subjected to a membrane electrolysis process, etc., so as to be operated as, for example, a semi-continuous process or a continuous process.

For example, the method may include subjecting a first aqueous composition containing lithium sulfate and/or lithium bisulfate to a membrane electrolysis process under suitable conditions for partially converting the lithium sulfate and/or lithium bisulfate into lithium hydroxide at a conversion rate of about 30% to about 70%, about 30% to about 60%, about 40% to about 55%, about 45% to about 55%, about 40% to about 50%, or about 45% to about 60%, and obtaining a second aqueous composition containing lithium sulfate and/or lithium bisulfate; and using the second aqueous composition containing lithium sulfate and/or lithium bisulfate as an aqueous composition containing lithium bisulfate for mixing with a lithium-containing material and obtaining a mixture.

Without wishing to be bound by this theory, the applicant believes that lithium bisulfate, for example, when present in the compositions of the present disclosure, can act as a buffer during the membrane electrolysis process, thereby aiding in the production of lithium hydroxide. For example, such a buffer allows for increased current efficiency when producing lithium hydroxide.

It has been observed that when concentrating the second composition and/or removing water from the second composition (during the membrane electrolysis process), it is possible to substantially selectively precipitate lithium sulfate (in the form of lithium sulfate monohydrate) and to separate at least a portion of the lithium sulfate from the acid (sulfuric acid). Alternatively, it is possible to substantially selectively precipitate anhydrous lithium sulfate.

Those skilled in the art will appreciate that one or more parameters of the disclosed methods may be monitored, for example, by means known in the art, such as, but not limited to, pH, temperature, current density,

Voltage, current efficiency and concentration. Suitable means for monitoring specific parameters in the method of the present disclosure can be selected by those skilled in the art. Such parameters can also be maintained and/or changed by those skilled in the art, for example, according to their common knowledge and with reference to the present disclosure.

Example

Example 1: Sodium bisulfate roasting test

Seven β-spodumene bisulfate roasting trials and one standard roasting trial were conducted. The objectives of the trials included ensuring that the spodumene phase transition occurred during the 1050°C roasting; collecting experimental data for comparison with bisulfate roasting results; and investigating the effects of temperature and/or _NaHSO₄ concentration on the bisulfate roasting test results.

Based on the stoichiometric requirements for the amount of lithium in the β-spodumene, a reaction slurry for sulfation was prepared by mixing the β-spodumene with a 30%, 50% or 100% excess of the desired sulfation reagent.

The acidic mixture was then baked in a muffle furnace under standard conditions using either a 250°C or 300°C furnace temperature. The baking time at the target temperature was 30 minutes, with a total baking time of 1.5-2 hours. The baked β-spodumene was then subjected to water leaching to determine the extent of lithium conversion. Table 1 summarizes the results of the bisulfate roasting and roasting tests using different parameters.

Table 1

^[1] A 30% excess of sodium bisulfate is added, and a 30% excess of sulfuric acid is added to the bisulfate solution before calcination.

In Table 1, sodium bisulfate was used as the reagent to better distinguish between the base added as the reagent and the lithium extracted from B-spodumene but converted to a mixture of lithium sulfate and sodium sulfate.

The water leaching tests for the bisulfate and roasting runs reported in Table 1 show that the highest Li % extraction of 97.4% was achieved in the bisulfate roasting run T7 when a mixture of sulfuric acid and sodium bisulfate solution was used as the sulfuric acid reagent in the roasting process.

At 100% stoichiometric excess, 94.3% Li extraction was achieved in bisulfate roasting run T6 using bisulfate as the sole sulfate reagent.

Example 2: Lithium bisulfate/sodium bisulfate roasting test

Using the procedure described in Example 1, studies were conducted using a mixture of _LiHSO₄ , _NaHSO₄ , and _{H₂SO₄ as} the sulfate reagent. The acidic mixture was then baked in a muffle furnace under standard conditions, using a 70°C solution, a furnace temperature of 250°C to 300°C, a bake time of 30 to 60 minutes at the target temperature, and a total bake time of 1.5-2.5 hours. The calcined β-spodumene was then subjected to water leaching to determine the extent of Li conversion. Table 2 summarizes the results of the bisulfate tests using different parameters.

Table 2 ^[1]

^[1] A mixture of LiHSO ₄ (85%) and NaHSO ₄ (15%) in a 1:1 ratio was used with the Li in the ore. Sulfuric acid was then added in stoichiometric excess as indicated.

The extraction values in Table 2 were calculated based on the Li content in the water leaching residue and the initial feed. It is clear from the above results that the extraction of Li increases with increasing amounts of acid used. In Table 2, lithium bisulfate was added to sodium bisulfate at a mass ratio of 15% to simulate the first composition that would be obtained during alkaline extraction, which would be obtained from a typical β-spodumene concentrate obtained from the extraction of α-spodumene ore.

Example 3: Cumulative Current Efficiency and Conductivity of the First Composition in the Alkali Hydroxide Production Test

Certain experiments have been conducted and are described in PCT/CA2014/000769 (incorporated herein by reference in its entirety) regarding the use of a two-compartment membrane electrolysis cell for the production of LiOH. The experiments are shown in Figures 3A-D of PCT/CA2014/000769;

Fig. 4A-D and Fig. 5A-D are merged and are shown in Fig. 2 of the present disclosure.Therefore, the parameter of the test shown in Fig. 2 and Fig. 3 of the present disclosure is identical with the test carried out in PCT/CA2014/000769.In Fig. 2 of the present disclosure, it can be seen that when compared with the result obtained with 3kA/ ^{m and} 5kA/m, the result of 4kA/ ^m is lower than expected (in the mode of current efficiency).These results of ^4kA /m are probably due to the technical failure during the test. However, as can be seen from Fig. 3 of the present disclosure (further test with the parameters identical with Fig. 2), the result of 4kA/ ^m looks consistent with 3kA/ ^m and 5kA/ ^m . Based on those results shown in Figures 2 and 3 of the present disclosure, converting lithium sulfate to lithium hydroxide at a conversion rate of about 30% to about 60%, about 40% to about 60%, about 40% to about 50%, about 40% to about 55%, or about 45% to about 55% and then using the remaining composition containing lithium bisulfate (the second aqueous composition) as the aqueous composition containing lithium bisulfate for mixing with a lithium-containing material and obtaining a mixture to be calcined can be an embodiment of the present disclosure.

Example 4: Lithium Bisulfate/Sodium Bisulfate Calcination Tests with Electrochemically Generated Bisulfate Ions

Using the procedure described in Example 1, studies were conducted using a mixture of LiHSO ₄ , NaHSO ₄ , and H ₂ SO ₄ as the sulfate reagent. The acidic mixture was then baked in a muffle furnace under standard conditions using a 250°C furnace temperature, with a bake time of 30 minutes at the target temperature and a total bake time of 1.5-2.75 hours. The calcined β-spodumene was then subjected to water leaching to determine the extent of Li conversion. Table 3 summarizes the results of the bisulfate tests using different parameters.

Table 3

^[1] A mixture of 80% bisulfate ( _LiHSO4 (85%) and _NaHSO4 (15%)) and 20% hydrogen cations from sulfuric acid on a molar basis was used in a 1:1 ratio with the Li in the ore. This mixture simulates the second composition that would be obtained from a membrane electrolysis process, during which lithium sulfate is converted to approximately 60% lithium hydroxide. A stoichiometric excess of sulfuric acid was then added as shown.

The extraction values in Table 3 were calculated based on the Li content in the water leach residue and the initial feed. From the above results it is clear that the electrochemically generated sulfuric acid proportionally reduced the excess sulfuric acid required compared to the Li extraction results obtained in Example 2.

Example 5: Removal of Water and Lithium Sulfate from Process Solution

Following the calcination test campaign, further tests were conducted to remove as much water as possible from the above composition before mixing with the lithium-containing material, based on different acidic mixtures simulating the second composition that would be obtained from the membrane electrolysis process.

When the mixture is heated, water is selectively removed by evaporation. When the mixture from which water has been removed reaches a boiling temperature of about 118°C, precipitate formation is observed. Figures 5 and 6 are XRD analyses of precipitated crystals recovered from the process. Figure 5 is obtained from the analysis of the precipitate recovered from Run 07A. Figure 5 shows that when the precipitate is formed at a temperature below about 125°C to 130°C, its chemical composition is essentially lithium sulfate monohydrate. Therefore, lithium sulfate monohydrate is substantially selectively precipitated and/or substantially selectively formed. Figure 6 is obtained from the analysis of the precipitate recovered from Run 04. It shows that when the precipitate is formed at a temperature of at least about 125°C to 130°C, at least a portion of the precipitate is dehydrated, thereby forming anhydrous lithium sulfate. Continuing such heating can result in substantial precipitation and/or formation of anhydrous lithium sulfate.

It was also observed that, contrary to the expected behavior of substantially pure lithium sulfate in aqueous solution, the recovery of lithium sulfate monohydrate increased significantly as the concentrated acidic mixture was cooled. As shown in Tables 5 and 6, which present data generated by two independent laboratories, for example, from about 35% to about 80% of the lithium sulfate can be separated as lithium sulfate monohydrate depending on the temperature at which the solution is cooled. Based on the data in Table 5, Figure 7 shows the lithium sulfate recovery efficiency under the separation step as a function of the mass basis of water removed at atmospheric pressure. It is apparent from this figure and the final boiling temperatures in Table 5 that most of the lithium sulfate precipitates in its monohydrate form at temperatures below 130°C.

It appears that this phenomenon, which would not have been anticipated from the very sparse literature on acidic aqueous lithium sulfate solutions, has operational advantages in the context of the present disclosure. Indeed, it can be recycled directly to the membrane electrolysis process, which is beneficial for adding very high purity or substantially pure raw materials from the main stream of lithium-containing material.

From these experiments, it was determined that the second composition (Composition A) obtained from Experiment 07A should be tested for use in calcining lithium-containing materials.

Based on this composition, a second evaporation step (07B) was tested in order to remove more water. Test 07A was further evaporated until a boiling temperature of about 200° C. was reached (composition B).

Table 5

Table 6

Those skilled in the art will appreciate that there are trade-offs between water removal, lithium recycling in the membrane electrolysis process, and the efficiency of the downstream roasting process with respect to the energy costs associated with recovering lithium sulfate at different temperatures. For example, under certain conditions, the costs associated with heating can be significantly high, and therefore it would be advantageous to perform filtration at a higher temperature to recover as much heat as possible. However, when energy costs permit, it is possible to perform solid-liquid separation at a lower temperature to precipitate a higher percentage of lithium sulfate.

Example 6: Calcination Tests with Treated By-Products

Using the procedure described in Example 1, the study was conducted using Compositions A and B identified in Example 5 as sulfate reagents. The acidic mixture was then baked in a muffle furnace under standard conditions using a furnace temperature of 250°C, with a baking time of 30 minutes at the target temperature. The baked β-spodumene was then subjected to water leaching to determine the extent of Li conversion. Table 7 summarizes the results of the baking tests using different compositions and stoichiometric excesses.

Table 7

The extraction values in Table 7 were calculated based on the water leaching residue and the Li content in the initial feed. It is clear from the above results that, compared to the Li extraction results obtained in Examples 2 and 4, Composition A shows similar performance, although it has the benefit of recycling lithium sulfate directly to the membrane electrolysis process mentioned in Example 5.

It is clear from the above results that compared to the Li extraction results obtained in Examples 2 and 4, Composition B shows better performance despite having the benefit of recycling lithium sulfate directly to the membrane electrolysis process as mentioned in Example 5.

All publications, patents, and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference in its entirety. When a term in this disclosure is found to be defined differently in a document incorporated by reference, the definition provided herein shall prevail.

Claims (138)

1. A method for preparing lithium hydroxide, the method comprising: The lithium-containing material is mixed with an acidic aqueous composition that optionally contains lithium sulfate, thereby obtaining a mixture; Under suitable conditions, the mixture is calcined to obtain a calcined lithium-containing material; The roasted material is leached under conditions suitable for obtaining a first aqueous composition containing lithium sulfate; Under suitable conditions, the first aqueous composition containing lithium sulfate is subjected to a membrane electrolysis process to at least partially convert the lithium sulfate into lithium hydroxide, and to obtain a second aqueous composition containing lithium sulfate; and Optionally increase the concentration of acid in the second aqueous composition; and The second aqueous composition containing lithium sulfate is used as the acidic aqueous composition optionally containing lithium sulfate for mixing with the lithium-containing material to obtain the mixture. The method further includes recovering lithium sulfate from the second aqueous composition and reusing the lithium sulfate in the membrane electrolysis process. 2. The method of claim 1, wherein, based on the amount of lithium in the lithium-containing material, there is a stoichiometric excess of the acid of 10% to 100%. 3. The method of claim 1, wherein, based on the amount of lithium in the lithium-containing material, there is a stoichiometric excess of the acid of 10% to 40%, 20% to 40%, or 55% to 60%. 4. The method according to any one of claims 1 to 3, wherein the mixture is calcined at a calcination temperature of 150°C to 400°C. 5. The method according to any one of claims 1 to 3, wherein the mixture is calcined at a calcination temperature of 200°C to 300°C. 6. The method according to any one of claims 1 to 3, wherein the mixture is calcined at a calcination temperature for 10 minutes to 24 hours. 7. The method according to any one of claims 1 to 3, wherein the mixture is calcined at a calcination temperature for 15 minutes to 2 hours. 8. The method according to any one of claims 1 to 3, wherein the lithium-containing material is a lithium-containing ore. 9. The method of claim 8, wherein the lithium-containing ore comprises β-spodumene or jadalite. 10. The method of claim 8, wherein the lithium-containing ore comprises β-spodumene. 11. The method of any one of claims 1 to 3, wherein the calcined lithium-containing material is leached with water to obtain the first aqueous composition comprising the lithium sulfate. 12. The method of any one of claims 1 to 3, wherein the lithium-containing material further comprises leached metal impurities, and the first aqueous composition comprising lithium sulfate is further treated under conditions suitable for removing at least a portion of the leached metal impurities from the first aqueous composition comprising the lithium sulfate. 13. A method for preparing lithium hydroxide, the method comprising: Under suitable conditions, a first aqueous composition containing lithium sulfate is subjected to a membrane electrolysis process to at least partially convert the lithium sulfate into lithium hydroxide, and to obtain a second aqueous composition containing lithium sulfate; and Optionally increase the concentration of acid in the second aqueous composition; and The second aqueous composition containing lithium sulfate is used to react with a lithium-containing material. The method further includes recovering lithium sulfate from the second aqueous composition and reusing the lithium sulfate in the membrane electrolysis process. 14. The method of any one of claims 1 to 3 and 13, wherein the method further comprises recovering at least a portion of lithium sulfate from the second aqueous composition before using the second aqueous composition to react with the lithium-containing material, and reusing the lithium sulfate in the membrane electrolysis process. 15. A method for preparing lithium hydroxide, the method comprising: Under suitable conditions, a first aqueous composition containing lithium sulfate is subjected to a membrane electrolysis process to at least partially convert the lithium sulfate into lithium hydroxide, and to obtain a second aqueous composition containing lithium sulfate; and Optionally increase the concentration of acid in the second aqueous composition; and Lithium sulfate is recovered from the second aqueous composition and reused in the membrane electrolysis process. 16. The method of any one of claims 1, 13, and 15, wherein the method comprises increasing the concentration of acid in the second aqueous composition by removing water from the second aqueous composition. 17. The method of claim 16, wherein the concentration of the acid is increased by heating the second aqueous composition. 18. The method of claim 17, wherein the second aqueous composition is heated at a temperature of 100°C to 300°C. 19. The method of claim 17, wherein the second aqueous composition is heated at a temperature of 110°C to 130°C. 20. The method of claim 17, wherein the second aqueous composition is heated at a temperature of 115°C to 25°C. 21. The method of any one of claims 1, 13 and 15, wherein the second aqueous composition is heated under reduced pressure or vacuum. 22. The method of any one of claims 1, 13 and 15, wherein the second aqueous composition is heated at atmospheric pressure. 23. The method of claim 16, wherein the concentration of the acid is increased by membrane dehydration, by reverse osmosis, or by adding some acid. 24. The method of claim 17, wherein removing water from the second aqueous composition causes precipitation of lithium sulfate monohydrate. 25. The method of claim 16, wherein removing water from the second aqueous composition causes selective precipitation of lithium sulfate monohydrate. 26. The method of claim 16, wherein removing water from the second aqueous composition causes crystallization of lithium sulfate monohydrate. 27. The method of any one of claims 1, 13, and 15, wherein the method comprises selectively precipitating lithium sulfate by increasing the concentration of acid in the second aqueous composition by removing water from the second aqueous composition. 28. The method of claim 24, further comprising performing solid-liquid separation to recover the lithium sulfate, thereby obtaining the lithium sulfate and the acidic composition. 29. The method of claim 28, wherein the solid-liquid separation is performed at a temperature of 15°C to 130°C. 30. The method of claim 28, wherein the solid-liquid separation is performed at a temperature of 25°C to 125°C. 31. The method of claim 24, further comprising performing solid-liquid separation to recover the lithium sulfate, thereby obtaining the lithium sulfate and an acidic aqueous compound effective for mixing with lithium-containing materials. 32. The method of claim 31, wherein the solid-liquid separation is performed at a temperature of 15°C to 130°C. 33. The method of claim 31, wherein the solid-liquid separation is performed at a temperature of 25°C to 125°C. 34. The method of any one of claims 1, 13 and 15, wherein the method comprises recovering lithium sulfate in the form of lithium sulfate monohydrate from the second aqueous composition and reusing the lithium sulfate in the membrane electrolysis process. 35. The method of any one of claims 1, ₁₃ and 15, wherein the acid is _H₂SO₄ . 36. A method for treating an aqueous composition containing lithium sulfate in a membrane electrolysis process, the method comprising removing water from the aqueous composition of the membrane electrolysis process under conditions suitable for selectively precipitating lithium sulfate monohydrate. 37. The method of claim 36, wherein water is removed by heating the aqueous composition of the membrane electrolysis process at a temperature of 100°C to 125°C or at a temperature of 100°C to 135°C. 38. The method of claim 37, wherein the aqueous composition is heated at atmospheric pressure. 39. The method of any one of claims 36 to 38, further comprising performing solid-liquid separation to recover the lithium sulfate, thereby obtaining the lithium sulfate and the acidic composition. 40. The method of claim 39, wherein the solid-liquid separation is performed at a temperature of 15°C to 130°C. 41. The method of claim 39, wherein the solid-liquid separation is performed at a temperature of 25°C to 125°C. 42. The method of any one of claims 36 to 38, further comprising performing solid-liquid separation to recover the lithium sulfate, thereby obtaining the lithium sulfate and an acidic aqueous substance effectively used for mixing with lithium-containing materials. 43. The method of claim 42, wherein the solid-liquid separation is performed at a temperature of 15°C to 130°C. 44. The method of claim 42, wherein the solid-liquid separation is performed at a temperature of 25°C to 125°C. 45. The method of any one of claims 36 to 38, further comprising reusing the obtained lithium sulfate in the membrane electrolysis process. 46. A method for extracting lithium from a lithium-containing material, the method comprising leaching the lithium-containing material roasted with lithium bisulfate under conditions suitable for obtaining an aqueous composition containing a lithium compound. 47. The method of claim 46, wherein the lithium-containing material calcined from lithium bisulfate is prepared by a method comprising: The lithium-containing material is mixed with an aqueous composition containing lithium bisulfate to obtain a mixture; and The mixture is calcined under suitable conditions to obtain the lithium-containing material calcined from the lithium bisulfate. 48. The method of claim 47, wherein the molar ratio between the lithium bisulfate in the aqueous composition comprising lithium bisulfate and the lithium in the lithium-containing material is from 0.5:1 to 4:1. 49. The method of any one of claims 46 to 48, wherein the aqueous composition comprising lithium bisulfate further comprises sulfuric acid. 50. The method of claim 49, wherein the molar ratio between the sulfuric acid in the aqueous composition comprising lithium bisulfate and the lithium in the lithium-containing material is from 0.5:1 to 4:1. 51. The method of claim 49, wherein the sulfuric acid is present in an excess of 10% to 40%, 20% to 40%, or 55% to 60% stoichiometrically based on the amount of lithium in the lithium-containing material. 52. The method of claim 47 or 48, wherein the mixture is calcined at a calcination temperature of 200°C to 325°C. 53. The method of claim 47 or 48, wherein the mixture is calcined at the calcination temperature for 10 minutes to 24 hours. 54. The method of any one of claims 46 to 48, wherein the lithium-containing material is a lithium-containing ore. 55. The method of claim 54, wherein the lithium-containing ore comprises β-spodumene or jadalite. 56. The method of any one of claims 46 to 48, wherein the lithium-containing material calcined from the lithium bisulfate is leached with water to obtain the aqueous composition comprising the lithium compound. 57. The method of any one of claims 46 to 48, wherein the lithium-containing material further comprises leached metal impurities, and the aqueous composition comprising the lithium compound is further treated under conditions suitable for removing at least a portion of the leached metal impurities from the aqueous composition comprising the lithium compound. 58. The method of any one of claims 46 to 48, wherein the aqueous composition comprising a lithium compound is an aqueous composition comprising lithium sulfate and/or lithium hydrogen sulfate. 59. The method of claim 58, wherein the aqueous composition comprising lithium sulfate and/or lithium bisulfate is an aqueous composition comprising lithium sulfate. 60. A method for preparing lithium hydroxide, the method comprising: A first aqueous composition comprising lithium sulfate and/or lithium bisulfate is obtained by the method for extracting lithium from a lithium-containing material according to any one of claims 46 to 48; and Under suitable conditions, the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is subjected to a membrane electrolysis process to at least partially convert the lithium sulfate and/or lithium bisulfate into lithium hydroxide. 61. The method of any one of claims 1, 13, 15 and 36, wherein the pH of the lithium sulfate and/or lithium bisulfate composition is acidic during the membrane electrolysis process. 62. The method of any one of claims 1, 13, 15 and 36, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process; a three-chamber single-stage or bipolar membrane electrolysis process; or a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 63. The method of claim 61, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process. 64. The method of claim 61, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process. 65. The method of claim 61, wherein the membrane electrolysis process comprises a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 66. The method of claim 61, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process, and wherein the pH is maintained at 2 to 4 during the three-chamber single-stage or bipolar membrane electrolysis process. 67. The method of claim 61, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and wherein the conversion of the lithium sulfate and/or lithium bisulfate to lithium hydroxide is carried out until the pH value of the lithium sulfate and/or lithium bisulfate composition is 0.1 to 2.0, 0.2 to 1.0, or 0.4 to 1.0. 68. The method of any one of claims 1, 13, 15 and 36, wherein the pH of the lithium sulfate and/or lithium hydrogen sulfate composition is alkaline during the membrane electrolysis process. 69. The method of claim 68, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process; a three-chamber single-stage or bipolar membrane electrolysis process; or a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 70. The method of claim 68, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process. 71. The method of claim 68, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process. 72. The method of claim 68, wherein the membrane electrolysis process comprises a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 73. The method of claim 68, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process, and wherein during the three-chamber single-stage or bipolar membrane electrolysis process, the pH is maintained at 10 to 12 or at 10.5 to 12.5. 74. The method of claim 60, wherein the method comprises: Under suitable conditions, the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is subjected to the membrane electrolysis process to at least partially convert the lithium sulfate and/or lithium bisulfate into lithium hydroxide and obtain a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and The second aqueous composition comprising lithium sulfate and/or lithium bisulfate is used as the aqueous composition comprising lithium bisulfate in the method of claim 48. 75. The method of claim 74, wherein the method comprises: Under suitable conditions, the first aqueous composition containing lithium sulfate and/or lithium bisulfate is subjected to a two-compartment single-stage or bipolar membrane electrolysis process to obtain a second aqueous composition containing lithium sulfate and/or lithium bisulfate; and The second aqueous composition comprising lithium sulfate and/or lithium bisulfate is used as the aqueous composition comprising lithium bisulfate in the method of claim 48. 76. The method of claim 74 or 75, wherein the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate is at least 3:2, at least 9:1, at least 19:1, or at least 99:1. 77. The method of claim 65, wherein the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate is 3:2 to 99:1. 78. The method of claim 74 or 75, wherein the second aqueous composition comprising lithium sulfate and/or lithium bisulfate comprises lithium bisulfate, and the method further comprises adding an alkali to a portion of the second aqueous composition comprising lithium sulfate and/or lithium bisulfate under conditions suitable for converting at least a portion of the lithium bisulfate to lithium sulfate. 79. The method of claim 78, wherein the base comprises calcium hydroxide, calcium oxide, and/or calcium carbonate. 80. The method of any one of claims 1, 13, 15 and 36, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and the voltage is maintained at 4V to 5V during the two-chamber single-stage or bipolar membrane electrolysis process. 81. The method of any one of claims 1, 13, 15 and 36, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and during the two-chamber single-stage or bipolar membrane electrolysis process, the current efficiency of LiOH is maintained at 65% to 85%. 82. The method of any one of claims 1, 13, 15 and 36, wherein the lithium concentration in the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is maintained at 20 g lithium per liter of solution to 40 g lithium per liter of solution, or 30 g lithium per liter of solution to 33 g lithium per liter of solution. 83. The method of any one of claims 1, 13, 15 and 36, wherein the lithium concentration in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate is maintained at 20 g lithium per liter to 40 g lithium per liter, 10 g lithium per liter to 20 g lithium per liter, 5 g lithium per liter to 40 g lithium per liter, or 12 g lithium per liter to 18 g lithium per liter. 84. The method of any one of claims 1, 13, 15 and 36, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and during the two-chamber single-stage or bipolar membrane electrolysis process, the lithium hydroxide is generated in an aqueous solution in which the lithium hydroxide concentration is maintained at 2M to 7M, 2M to 4M, or 2.5M to 3.5M. 85. The method of claim 84, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and during the two-chamber single-stage or bipolar membrane electrolysis process, the lithium hydroxide is generated in an aqueous solution at a temperature maintained between 40°C and 100°C or between 60°C and 100°C. 86. A method for preparing lithium hydroxide, the method comprising: A lithium-containing material is mixed with an aqueous composition containing lithium bisulfate, thereby obtaining a mixture; The mixture is calcined under suitable conditions to obtain a lithium-containing material calcined from lithium bisulfate; Under conditions suitable for obtaining a first aqueous composition comprising lithium sulfate and/or lithium bisulfate, the lithium-containing material calcined from the lithium bisulfate is leached. Under suitable conditions, the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is subjected to a membrane electrolysis process to at least partially convert the lithium sulfate and/or lithium bisulfate into lithium hydroxide, and to obtain a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and The second aqueous composition containing lithium sulfate and/or lithium bisulfate is used as the aqueous composition containing lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 87. The method of claim 86, wherein the molar ratio between the lithium bisulfate in the aqueous composition comprising lithium bisulfate and the lithium in the lithium-containing material is from 0.5:1 to 4:1. 88. The method of claim 86, wherein the molar ratio between the lithium bisulfate in the aqueous composition comprising lithium bisulfate and the lithium in the lithium-containing material is 1:1 to 2:1. 89. The method of any one of claims 86 to 88, wherein the aqueous composition comprising lithium bisulfate further comprises sulfuric acid. 90. The method of claim 89, wherein the molar ratio between the sulfuric acid in the aqueous composition comprising lithium bisulfate and the lithium in the lithium-containing material is 0.5:1 to 4:1, 1:1 to 2:1, or 1.1:1 to 1.25:1. 91. The method of claim 90, wherein, based on the amount of lithium in the lithium-containing material, there is a stoichiometric excess of the sulfuric acid of 30% to 100%. 92. The method of claim 90, wherein, based on the amount of lithium in the lithium-containing material, there is a stoichiometric excess of 55% to 60% of the sulfuric acid. 93. The method of any one of claims 86 to 88, wherein the mixture is calcined at a calcination temperature of 150°C to 400°C or 200°C to 350°C. 94. The method of claim 93, wherein the mixture is calcined at the calcination temperature for 10 minutes to 24 hours. 95. The method of any one of claims 86 to 88, wherein the lithium-containing material is a lithium-containing ore. 96. The method of claim 95, wherein the lithium-containing ore comprises β-spodumene or jadalite. 97. The method of claim 95, wherein the lithium-containing ore comprises β-spodumene. 98. The method of any one of claims 86 to 88, wherein the lithium-containing material calcined from the lithium bisulfate is leached with water to obtain the first aqueous composition comprising lithium sulfate and/or lithium bisulfate. 99. The method of any one of claims 86 to 88, wherein the lithium-containing material further comprises leached metal impurities, and the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is further treated under conditions suitable for removing at least a portion of the leached metal impurities from the first aqueous composition comprising lithium sulfate and/or lithium bisulfate. 100. The method of any one of claims 1, 13, 15 and 36, wherein the pH of the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is acidic during the membrane electrolysis process. 101. The method of claim 100, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process; a three-chamber single-stage or bipolar membrane electrolysis process; or a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 102. The method of claim 100, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process. 103. The method of claim 100, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process. 104. The method of claim 100, wherein the membrane electrolysis process comprises a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 105. The method of claim 100, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process, and wherein the pH is maintained at 2 to 4 during the three-chamber single-stage or bipolar membrane electrolysis process. 106. The method of claim 100, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and wherein the conversion of the lithium sulfate and/or lithium bisulfate to lithium hydroxide is carried out until the pH of the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is 0.1 to 2.0, 0.2 to 1.5, or 0.4 to 1.0. 107. The method of any one of claims 1, 13, 15 and 36, wherein the pH of the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is alkaline during the membrane electrolysis process. 108. The method of claim 107, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process; a three-chamber single-stage or bipolar membrane electrolysis process; or a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 109. The method of claim 107, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process. 110. The method of claim 107, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process. 111. The method of claim 107, wherein the membrane electrolysis process comprises a combination of a two-chamber single-stage or bipolar membrane electrolysis process and a three-chamber single-stage or bipolar membrane electrolysis process. 112. The method of claim 107, wherein the membrane electrolysis process comprises a three-chamber single-stage or bipolar membrane electrolysis process, and wherein during the three-chamber single-stage or bipolar membrane electrolysis process, the pH is maintained at 10 to 12, or at 10.5 to 12.5. 113. The method of claim 86, wherein the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is an aqueous composition comprising lithium sulfate. 114. The method of claim 86, wherein the molar ratio between lithium sulfate and lithium bisulfate in the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is at least 9:1, at least 19:1, or at least 99:1. 115. The method of claim 86, wherein the molar ratio between lithium bisulfate and lithium sulfate in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate is at least 3:2, at least 9:1, at least 19:1, or at least 99:1. 116. The method of claim 86, wherein the second aqueous composition comprising lithium sulfate and/or lithium bisulfate comprises lithium bisulfate, and the method further comprises adding an alkali to a portion of the second aqueous composition comprising lithium sulfate and/or lithium bisulfate under conditions suitable for converting at least a portion of the lithium bisulfate to lithium sulfate. 117. The method of claim 116, wherein the base comprises calcium hydroxide. 118. The method of any one of claims 1, 13, 15, 36 and 86, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and the voltage is maintained at 4V to 5V during the two-chamber single-stage or bipolar membrane electrolysis process. 119. The method of any one of claims 1, 13, 15, 36, and 86, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and during the two-chamber single-stage or bipolar membrane electrolysis process, the LiOH current efficiency is maintained at 30% to 50%, 30% to 40%, 50% to 95%, 55% to 90%, or 65% to 85%. 120. The method of any one of claims 86 to 88 and 113 to 116, wherein the lithium concentration in the first aqueous composition comprising lithium sulfate and/or lithium bisulfate is maintained at 20 g lithium per liter of solution to 40 g lithium per liter of solution. 121. The method according to any one of claims 86 to 88 and 113 to 116, wherein the lithium concentration in the second aqueous composition comprising lithium sulfate and/or lithium bisulfate is maintained at 20 g lithium per liter to 40 g lithium per liter, 10 g lithium per liter to 20 g lithium per liter, 5 g lithium per liter to 40 g lithium per liter, or 12 g lithium per liter to 18 g lithium per liter. 122. The method of any one of claims 86 to 88 and 113 to 116, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and during the two-chamber single-stage or bipolar membrane electrolysis process, the lithium hydroxide is generated in an aqueous solution in which the lithium hydroxide concentration is maintained at 2M to 7M, 2M to 4M, or 2.5M to 3.5M. 123. The method of any one of claims 86 to 88 and 113 to 116, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and during the two-chamber single-stage or bipolar membrane electrolysis process, the lithium hydroxide is generated in an aqueous solution maintaining a lithium hydroxide concentration of 3.0 M. 124. The method of claim 122, wherein the membrane electrolysis process comprises a two-chamber single-stage or bipolar membrane electrolysis process, and the lithium hydroxide is generated in an aqueous solution at a temperature maintained at 60°C to 100°C during the two-chamber single-stage or bipolar membrane electrolysis process. 125. The method of any one of claims 86 to 88 and 113 to 116, wherein the method comprises: The lithium-containing material is mixed with the aqueous composition containing lithium bisulfate, thereby obtaining the mixture; The mixture is calcined under suitable conditions to obtain the lithium-containing material calcined from the lithium bisulfate; Lithium-containing materials calcined from lithium bisulfate are leached under conditions suitable for obtaining the first aqueous composition comprising lithium sulfate and/or lithium bisulfate. The first aqueous composition containing lithium sulfate and/or lithium hydrogen sulfate is purified; Under suitable conditions, the purified first aqueous composition containing lithium sulfate and/or lithium bisulfate is subjected to the membrane electrolysis process to at least partially convert the lithium sulfate and/or lithium bisulfate into lithium hydroxide, and to obtain the second aqueous composition containing lithium sulfate and/or lithium bisulfate; and The second aqueous composition containing lithium sulfate and/or lithium bisulfate is used as the aqueous composition containing lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 126. The method of any one of claims 1, 13, 15, 36 and 86, wherein the calcination and the leaching are performed in a single apparatus. 127. The method of any one of claims 1, 13, 15, 36 and 86, wherein the calcination is carried out in a first apparatus and the leaching is carried out in a second apparatus. 128. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises, under suitable conditions, subjecting a first aqueous composition comprising lithium sulfate and/or lithium bisulfate to a membrane electrolysis process, partially converting the lithium sulfate and/or lithium bisulfate to lithium hydroxide at a conversion rate of 30% to 60%, and obtaining a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and using the second aqueous composition comprising lithium sulfate and/or lithium bisulfate as the aqueous composition comprising lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 129. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises subjecting a first aqueous composition comprising lithium sulfate and/or lithium bisulfate to a membrane electrolysis process under suitable conditions to partially convert the lithium sulfate and/or lithium bisulfate to lithium hydroxide at a conversion rate of 40% to 60%, and obtaining a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and using the second aqueous composition comprising lithium sulfate and/or lithium bisulfate as the aqueous composition comprising lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 130. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises subjecting a first aqueous composition comprising lithium sulfate and/or lithium bisulfate to a membrane electrolysis process under suitable conditions to partially convert the lithium sulfate and/or lithium bisulfate to lithium hydroxide at a conversion rate of 45% to 55%, and obtaining a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and using the second aqueous composition comprising lithium sulfate and/or lithium bisulfate as the aqueous composition comprising lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 131. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises subjecting a first aqueous composition comprising lithium sulfate and/or lithium bisulfate to a membrane electrolysis process under suitable conditions to partially convert the lithium sulfate and/or lithium bisulfate to lithium hydroxide at a conversion rate of 40% to 50%, and obtaining a second aqueous composition comprising lithium sulfate and/or lithium bisulfate; and using the second aqueous composition comprising lithium sulfate and/or lithium bisulfate as the aqueous composition comprising lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 132. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises subjecting the first aqueous composition containing lithium sulfate to a membrane electrolysis process under suitable conditions to partially convert the lithium sulfate to lithium hydroxide at a conversion rate of 30% to 60%, and obtaining a second aqueous composition containing lithium bisulfate; and using the second aqueous composition containing lithium bisulfate as the aqueous composition containing lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 133. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises subjecting the first aqueous composition containing lithium sulfate to a membrane electrolysis process under suitable conditions to partially convert the lithium sulfate to lithium hydroxide at a conversion rate of 40% to 60%, and obtaining a second aqueous composition containing lithium bisulfate; and using the second aqueous composition containing lithium bisulfate as the aqueous composition containing lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 134. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises subjecting the first aqueous composition containing lithium sulfate to a membrane electrolysis process under suitable conditions to partially convert the lithium sulfate to lithium hydroxide at a conversion rate of 45% to 55%, and obtaining a second aqueous composition containing lithium bisulfate; and using the second aqueous composition containing lithium bisulfate as the aqueous composition containing lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 135. The method of any one of claims 1, 13, 15, 36, 46, and 86, wherein the method comprises subjecting the first aqueous composition containing lithium sulfate to a membrane electrolysis process under suitable conditions to partially convert the lithium sulfate to lithium hydroxide at a conversion rate of 40% to 50%, and obtaining a second aqueous composition containing lithium bisulfate; and using the second aqueous composition containing lithium bisulfate as the aqueous composition containing lithium bisulfate for mixing with the lithium-containing material to obtain the mixture. 136. The method of any one of claims 1, 13, 15, 36, 46 and 86, wherein the membrane electrolysis process is carried out in a two-chamber membrane electrolysis process. 137. The method of any one of claims 1, 13, 15, 36, 46 and 86, wherein the membrane electrolysis process is an electrolysis process. 138. The method of any one of claims 1, 13, 15, 36, 46 and 86, wherein the membrane electrolysis process is an electrodialysis process.