Method for obtaining a lithiated bayerite and resulting product

Abstract

The invention relates to a method for manufacturing a product comprising a lithiated bayerite, which method comprises bringing an aluminum source consisting of an aluminum hydroxide or of an aluminum hydroxide and boehmite, said aluminum source comprising at least 10% by weight of an amorphous aluminum hydroxide, into contact with an aqueous solution comprising a base, such that the molar ratio between the OH provided by said base and the Al present in said aluminum source is greater than 0.20, and with an aqueous solution comprising a chlorine salt, such that the molar ratio between the Cl provided by said chlorine salt and the Al present in said aluminum source is greater than 0.25, said base and / or said chlorine salt comprising lithium, and the respective amounts thereof being chosen so as to provide an amount of lithium such that the Li / Al molar ratio is greater than or equal to 1.

Description

Process for obtaining a lithium-rich bayerite and product obtained

[0001] The present invention relates to a product comprising lithiated bayerite and to a method of manufacturing a product comprising lithiated bayerite.

[0002] The use of lithium, particularly in batteries, is constantly increasing.

[0003] Brines are sources of lithium, for which lithium extraction is necessary. This extraction, or capture, can be carried out using columns filled with an active material that selectively and reversibly captures lithium when the brine comes into contact with it. The lithium is then recovered by passing an aqueous solution through these columns. This results in a concentrated lithium solution that is purified before a precipitation step, generally in the form of lithium carbonate.

[0004] Lithium adsorbents, in particular lithium bayerite, are advantageously used as active materials to obtain concentrated lithium solutions in extraction columns.

[0005] EP 4 490 106 describes a product comprising lithia-treated bayerite and a process for manufacturing such a product, a process in which an aluminium hydroxide selected from gibbsite, bayerite, doyleite, nordstrandite and mixtures thereof may be used.

[0006] US4,348,295 describes a process for manufacturing LiX·2Al(OH)3·nH2O, where X is an anion that forms an acid in molecular combination with H₂ or a salt in combination with a metal ion. The process includes a step of reacting hydrated alumina with a concentrated LiX solution at a temperature above 85°C. However, the material obtained by this process exhibits limited lithium adsorption capacity.

[0007] WO2018 / 002336 describes a process for manufacturing (LiCl) x .2Al(OH)3.nH2O comprising a step of boehmite precipitation, then a step of contacting the precipitate obtained with LiCl, then a filtration step, then a drying step, then a kneading-extrusion step in the presence of an acid and finally a drying step.

[0008] There is a need for a product comprising lithium-containing bayerite with a longer lifespan and high lithium adsorption capacity, obtainable by a simpler process. The object of the invention is to satisfy this need. Other advantages of the invention will be described later in the text.

[0009] To this end, the invention relates to a method for manufacturing a product comprising a lithiated bayerite, said method comprising a step of bringing into contact an aluminium source consisting of aluminium hydroxide or consisting of aluminium hydroxide and boehmite, said aluminium source comprising at least 10% by weight of an amorphous aluminium hydroxide, with a) an aqueous solution comprising a base, such that the molar ratio between the OH supplied by said base and the Al present in said aluminium source is greater than 0.20, and b) an aqueous solution comprising a chlorine salt, such that the molar ratio between the Cl supplied by said chlorine salt and the Al present in said aluminium source is greater than 0.25;said base and / or said chlorine salt comprising lithium, and their respective quantities being chosen so as to provide an amount of lithium such that the Li / Al molar ratio is greater than or equal to 1.

[0010] Unlike aluminum hydroxide, which typically contains a significant amount of crystalline phase, amorphous aluminum hydroxide is defined as having less than 30% crystalline phase by mass, based on the mass of the product. In other words, amorphous aluminum hydroxide contains at least 70% amorphous phase by mass, based on the mass of the product.

[0011] The aluminum source preferably consists of aluminum hydroxide. In another embodiment, it comprises boehmite in addition to aluminum hydroxide. In this case, the aluminum source consists of a mixture of aluminum hydroxide and boehmite.

[0012] Preferably, the molar ratio between the OH supplied by the base and the Al present in said aluminum source is greater than 0.4, preferably greater than or equal to 0.5, and / or preferably less than 10, preferably less than 9, preferably less than 8, preferably less than 7, preferably less than 6, preferably less than 5, preferably less than 4, preferably less than 3, preferably less than 2, preferably less than 1.5. The molar ratio between the OH supplied by the base and the Al present in said aluminum source is advantageously between 0.4 and 5, preferably between 0.5 and 2.

[0013] Preferably, the said base does not contain the aluminum element.

[0014] Preferably, the base is chosen from NaOH, LiOH, NH4OH, KOH, Ca(OH)2, RbOH, CsOH, Sr(OH)2, Ba(OH)2, Mg(OH)2, and mixtures thereof. Preferably, the base is chosen from NaOH, LiOH, NH4OH, and mixtures thereof. Preferably, the base is LiOH.

[0015] Preferably, the molar ratio between the Cl supplied by the chlorine salt and the Al present in the aluminum source is preferably greater than 0.5, and preferably less than 10, preferably less than 9, preferably less than 8, preferably less than 7, preferably less than 6, preferably less than 5, preferably less than 4, preferably less than 3. The molar ratio between the Cl supplied by the chlorine salt and the Al present in the aluminum source is advantageously between 0.5 and 6, in particular between 0.5 and 3.

[0016] Preferably, chlorine salt does not contain the element aluminium.

[0017] Preferably, the chlorine salt is chosen from LiCl, NaCl, KCl, CaCl2, NH4Cl, MgCl2 and mixtures thereof. Preferably the chlorine salt is LiCl.

[0018] Preferably, said base and / or said chlorine salt comprises lithium, and their respective amounts are chosen so as to provide an amount of lithium such that the Li / Al molar ratio is greater than 1.1, preferably greater than 1.2, and preferably less than 4, preferably less than 2.

[0019] Preferably, the aluminum source comprises at least 20% by weight, in particular at least 30% by weight, or even at least 40% or at least 50% by weight, and even at least 60% or 70% by weight, advantageously at least 80% or at least 90% by weight, of amorphous aluminum hydroxide. The aluminum source may comprise, in addition to amorphous aluminum hydroxide, boehmite and / or crystalline aluminum hydroxide, the latter being selected in particular from gibbsite, bayerite, doyleite, and nordstrandite.

[0020] The aluminum source is advantageously brought into contact with an aqueous solution comprising both the base and the chlorine salt. In other words, solutions a) and b) are one and the same solution, and the contact is made with this solution.

[0021] Alternatively, in a less preferred variant, the aluminum source can be brought into contact successively with the aqueous solution comprising the base, then with the aqueous solution comprising the chlorine salt, or conversely with the aqueous solution comprising the chlorine salt, then with the aqueous solution comprising the base.

[0022] The contacting step is preferably carried out by suspending the aluminum source in an aqueous solution, particularly an aqueous solution containing the base and the chlorine salt. In the less preferred variant just described, the contacting step can be carried out, for example, by suspending the source in an aqueous solution containing a base, then adding a chlorine salt, or conversely, by suspending the source in an aqueous solution containing a chlorine salt, then adding a base. Other contacting methods will be described later in the text.

[0023] Preferably, the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is carried out at a temperature below 50°C, preferably below 40°C, preferably below 30°C, preferably less than or equal to 25°C. In a particularly preferred embodiment, the contacting step is carried out at room temperature. In another embodiment, the contacting step is carried out at a temperature below 20°C, preferably below 15°C, preferably below 10°C, preferably below 5°C, or even below 1°C.

[0024] According to a less preferred alternative, the step of bringing the aluminium source into contact with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is carried out in such a way that at least part of these steps takes place at a temperature greater than or equal to 50°C and less than or equal to 60°C.

[0025] The duration of the step of bringing the aluminum source into contact with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt, referred to as the "contact time" hereafter, corresponds to the duration of the step during which the aluminum source is in contact with both the base and the chlorine salt. Thus, depending on the embodiment, this contact time is counted from the moment the aluminum source comes into contact: - with the aqueous solution comprising a base after having been brought into contact with the aqueous solution comprising a chlorine salt, or - with the aqueous solution comprising a chlorine salt after having been brought into contact with the aqueous solution comprising a base, or - with the aqueous solution comprising both the base and the chlorine salt.

[0026] The contact time does not include the optional acidification step, the optional filtration step, the optional washing step, and the optional shaping step, which are described later. The contact time ends upon the occurrence of the first of the following events: the start of the optional acidification step, the start of the optional filtration step, the start of the optional washing step, and the start of the optional shaping step.

[0027] The contact time is preferably greater than 30 seconds, preferably greater than 1 minute, preferably greater than 2 minutes, preferably greater than 3 minutes, preferably greater than 4 minutes, and preferably less than 15 hours, preferably less than 10 hours, preferably less than 7 hours. The contact time of the aluminum source with the aqueous solution containing a base and with the aqueous solution containing a chlorine salt depends, in particular, on the temperature and the median size of the aluminum source. Those skilled in the art know how to adjust this contact time according to the temperature and the median size of the aluminum source. A smaller median size or a higher contact temperature generally reduces the contact time required to convert the aluminum source to lithium bayerite.

[0028] Where at least part of the contacting step and / or at least part of the optional acidification step and / or at least part of the optional filtration step and / or at least part of the optional washing step, the optional acidification, filtration and washing steps being described later, takes place at a temperature greater than or equal to 50°C and less than or equal to 60°C, the cumulative time during which the temperature is greater than or equal to 50°C and less than or equal to 60°C is less than 15 hours, preferably less than 10 hours, preferably less than 7 hours, and preferably more than 30 seconds, preferably more than 1 minute, preferably more than 2 minutes, preferably more than 3 minutes, preferably more than 4 minutes.

[0029] The invention also relates to a product comprising a lithiated bayerite obtained by the process according to the invention. This product comprises, or is essentially composed of: - water, and - crystallites, at least a part, preferably all, of said crystallites being made up of lithiated bayerite, the average size of the lithiated bayerite crystallites being greater than or equal to 2 nm and less than or equal to 25 nm, and said product having a cumulative content of aluminium hydroxide and boehmite less than or equal to 10%, said product comprising at least the elements Li, Cl, Al, O and H, the elements Li, Cl and Al being present in said dry product in the following contents, determined by inductively coupled plasma spectrometry, in weight percentages: - 2% < Li < 5%, - 10% < Cl < 26%, - 15% < Al < 30%.

[0030] Preferably, this product is in the form of objects with dimensions of at least 0.2 mm and is essentially composed, in particular, of water and crystallites, at least a portion, preferably all, of said crystallites being composed of lithiated bayerite. "Essentially composed" means, in particular, that the product does not include any other element likely to affect the properties of the product or the manufacturing process, but may nevertheless include traces or impurities, in particular at levels below 0.4%, and in particular below 0.1% by weight. Specifically, the product does not include any binder, whether organic or mineral, and the shaping of the product does not require the use of a filler containing an acid, whether organic or mineral.

[0031] According to the various possible embodiments, the product of the invention can be in the form of a wax, for example after a filtration step, or in the form of an object with dimensions of at least 0.2 mm. Such an object may, in particular, but not exclusively, result from a shaping step of a filler containing the wax. As described in more detail later in the text, such an object, thanks to the process according to the invention, exhibits remarkable resistance to attrition, superior to that of prior art products obtained from aluminum sources other than amorphous aluminum hydroxide, even in the absence of a binder or other compound. Furthermore, the waxy appearance is distinct from the pasty or creamy appearance of products obtained according to the prior art.It has been observed that this waxy, more cohesive consistency allows for the production, after shaping, of objects with significantly improved attrition resistance, even without a binder. These objects can take the form of cylinders, polylobes, rings, or spheres. Preferably, all dimensions of these objects are less than 1.5 mm. They can be directly incorporated into a lithium capture device, particularly an extraction column.

[0032] The said product comprises, and preferably is essentially made up of, or even made up of: - water, and - crystallites, at least a part, preferably all of said crystallites being made up of lithiated bayerite, the average size of the lithiated bayerite crystallites being greater than or equal to 2 nm and less than or equal to 25 nm, and said product having a cumulative rate of aluminium hydroxide and boehmite less than or equal to 10%, said product comprising at least the elements Li, Cl, Al, O and H, the elements Li, Cl and Al being present in said dry product in the following amounts, determined by inductively coupled plasma spectrometry, in weight percentages: - 2% < Li < 5%, - 10% < Cl < 26%, - 15% < Al < 30%.

[0033] The average size of the lithiated bayerite crystallites and the cumulative rate of aluminium hydroxide and boehmite are measured on said product after exposure to air for 170 hours at 25°C, at atmospheric pressure.

[0034] The said dry product is obtained after drying under air at 200°C for 16 hours, at atmospheric pressure.

[0035] Preferably, the product shall have one or more of the following optional characteristics: - A water content greater than 1%, preferably greater than 5%, preferably greater than 10% and / or preferably less than 95%, preferably less than 90%, preferably less than 80%, or even less than 70%, or even less than 60%. The water content is the mass loss, expressed as a percentage, after drying at 200°C for 16 hours in air, at atmospheric pressure; - A cumulative aluminum hydroxide and boehmite content less than or equal to 8%, preferably less than or equal to 5%, preferably substantially zero;- The elements Li, Cl and Al are present in said product, after drying under air at 200°C for 16 hours, at atmospheric pressure, in the following contents, in percentages by weight: ▪ Li: preferably greater than 2.5%, preferably greater than 3%, and / or preferably less than 4.5%, preferably less than 4%, and ▪ Cl: preferably greater than 11%, preferably greater than 13% and / or preferably less than 24%, preferably less than 22%, and ▪ Al: preferably greater than 17%, preferably greater than 19% and / or preferably less than 29%, preferably less than 28%;- After drying in air at 200°C for 16 hours at atmospheric pressure, the following chemical analysis, determined by inductively coupled plasma spectrometry, in weight percentages: ▪ Li in a content greater than 2%, preferably greater than 2.5%, preferably greater than 3% and less than 5%, preferably less than 4.5%, preferably less than 4%, and ▪ Cl in a content greater than 10%, preferably greater than 11%, preferably greater than 13% and less than 26%, preferably less than 24%, preferably less than 22%, and ▪ Al in a content greater than 15%, preferably greater than 17%, preferably greater than 19% and less than 30%, preferably less than 29%, preferably less than 28%, and ▪ Elements other than Li, Cl, Al, O and H in a content less than 3%, preferably less than 2%, preferably less than 1%, and O and H in a content corresponding to the complement to 100%;- an average crystallite size of less than or equal to 23 nm, preferably less than or equal to 20 nm.;

[0036] According to one embodiment, the lithiated bayerite crystallites have an average size greater than or equal to 10 nm and less than or equal to 25 nm, preferably less than or equal to 23 nm, preferably less than or equal to 20 nm. According to another embodiment, possibly combinable with the previous one, the product does not include an organic binder, in particular does not include a binder.

[0037] According to one embodiment, the lithiated bayerite crystallites have an average size between 2 and less than 10 nm. According to another embodiment, possibly combinable with the previous one, the product does not include an organic binder, in particular does not include a binder.

[0038] According to one embodiment, the lithiated bayerite crystallites have an average size between 2 and 8 nm, in particular between 2 and 6 nm, or even between 6 and 8 nm. According to another embodiment, possibly combinable with the previous one, the product does not include an organic binder, in particular does not include any binder.

[0039] The compound with the formula Al(OH)3 is called "aluminum hydroxide". Gibbsite, bayerite, doyleite and nordstrandite are crystalline aluminum hydroxides. An "amorphous aluminum hydroxide" is called an aluminum hydroxide having, by mass percentages after drying in air at 200°C for 16 hours at atmospheric pressure, less than 10% impurities, the impurities being elements other than Al, O and H, and having an amount of amorphous phase greater than or equal to 70%, by mass on the basis of the mass of said amorphous aluminum hydroxide, measured on said amorphous aluminum hydroxide after exposure to air for 170 hours at 25°C at atmospheric pressure.

[0040] Preferably, an amorphous aluminium hydroxide has: - a content of elements other than Al, O and H of less than 8%, preferably less than 7%, preferably less than 6%, preferably less than 5%, preferably less than 4%, preferably less than 3%, preferably less than 2%, as a percentage by mass after drying in air at 200°C for 16 hours, at atmospheric pressure, and / or - an amount of amorphous phase greater than 75%, preferably greater than 80%, preferably greater than 85%, preferably greater than 90%, preferably greater than 95%, as a percentage by mass.

[0041] Preferably, when an amorphous aluminum hydroxide comprises at least one crystalline phase, a crystalline phase of aluminum hydroxide is present. Preferably, said crystalline phase of aluminum hydroxide is selected from gibbsite, bayerite, doyleite, nordstrandite, and mixtures thereof, preferably gibbsite.

[0042] The compound with the formula LiCl.2Al(OH)3.xH2O, as indicated in the ICDD PDF 00-031-0700, is called "lithia bayerite," but by extension, compounds with a ratio of the molar quantities of lithium and aluminum, Li / Al, other than 0.5 are also included. In some modes, it may be less than 0.5. In other modes, it may be greater than 0.5.

[0043] The compound with the formula γ-AlO(OH) is called “boehmite”.

[0044] The "cumulative percentage of aluminium hydroxide and boehmite" in a product is calculated according to the following formula (1):

[0045] T = 100* (A HA + A BO ) / (HAS HA + A BO + A BL ) (1)where A HAis the sum of the areas of the aluminum hydroxide phases, measured on an X-ray diffraction pattern of said product, for example obtained from a Bruker D8 Endeavor type instrument, equipped with a copper DX tube, without deconvolution treatment, after having eliminated the Kα2 line. The area of ​​an aluminum hydroxide phase is that of its diffraction peak located in an angular region 2θ approximately equal to 18.3°; A BO is the area of ​​the boehmite diffraction peak located in an angular domain 2θ approximately equal to 14°, measured on the same diagram, without deconvolution treatment, after eliminating the Kα2 line; A BL is the area of ​​the diffraction peak of the (003) plane of the lithiated bayerite located in an angular domain 2θ approximately equal to 11.3°, measured on the same diagram, without deconvolution treatment, after eliminating the Kα2 line.

[0046] According to the classical definition, "polysaccharides" are polymers composed of chains of sugar units linked by glycosidic bonds.

[0047] A polysaccharide capable of forming a gel under the action of a gelling agent is called a "gelable polysaccharide".

[0048] A gelled polysaccharide results from the association of polysaccharide chains under the action of a gelling agent. For example, alginate has the formula (C6H7O6). - ) n Alginate is a polysaccharide chain comprising carboxylate groups COO - Calcium ions (Ca) 2+ (gelling agent) react with two strands of alginate, that is, with the carboxylate groups COO - This leads to the polymerization of the alginate chains and the bonding of the molecules together. The reaction thus allows the creation of a gel.

[0049] The term "dry product" refers to a product obtained after drying under air at 200°C for 16 hours (at atmospheric pressure), this drying being classically carried out, for example, in an oven.

[0050] The "median size" of a powder or suspension of particles is defined as the size that divides the particles in the powder or suspension into first and second populations of equal mass, each consisting only of particles with a size greater than or equal to, or less than, respectively, the median size. The median size can, for example, be determined using a laser particle size analyzer.

[0051] A "binder" is any compound whose function is to bind particles together. An "organic binder" is a binder containing the element carbon, and at least one covalent CH bond or at least two carbon atoms with covalent bonds.

[0052] All percentages in this description are mass percentages unless otherwise stated.

[0053] The verbs "contain", "understand" and "present" should be interpreted broadly, without limitation, unless otherwise indicated.

[0054] According to a first preferred embodiment (referred to as "first embodiment" or simply "first embodiment" in the remainder of the text), the aluminum source comprises at least 90%, preferably at least 95% by weight of amorphous aluminum hydroxide, preferably consists of amorphous aluminum hydroxide.

[0055] Preferably, the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is carried out at a temperature below 50°C, preferably below 40°C, preferably below 30°C, and preferably at or below 25°C. In a particularly preferred embodiment, the contacting step is carried out at room temperature. In another embodiment, the contacting step is carried out at a temperature below 20°C, preferably below 15°C, preferably below 10°C, preferably below 5°C, or even below 1°C. It has been observed that in this embodiment, lithiased bayerite with small crystallites can be obtained, even at low temperatures.

[0056] According to a less preferred alternative, the step of bringing the aluminium source into contact with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is carried out in such a way that at least part of this step is carried out at a temperature greater than or equal to 50°C and less than or equal to 60°C.

[0057] The duration of contact of the aluminium source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is preferably greater than 30 seconds, preferably greater than 1 minute, preferably greater than 2 minutes, preferably greater than 3 minutes, preferably greater than 4 minutes, and preferably less than 5 hours, preferably less than 4 hours.

[0058] According to a first advantageous variant of the first embodiment, at least a portion of the amorphous aluminum hydroxide included in the aluminum source is in the form of objects with dimensions of at least 0.2 mm. Preferably more than 80%, and preferably more than 90% by mass, of the amorphous aluminum hydroxide present in the aluminum source is in the form of objects with dimensions of at least 0.2 mm.

[0059] These objects preferably have the shape of a cylinder, a polylobe, a ring, or a sphere. Preferably, more than 80%, and preferably more than 90% by mass, of the aluminum source is in the form of objects whose dimensions are all less than 1.5 mm.

[0060] In a preferred embodiment of this first variant of the first embodiment, the aluminum source constitutes a fixed bed, preferably located in an adsorption column. The contacting step is carried out by passing an aqueous solution comprising a base and an aqueous solution comprising a chlorine salt through the fixed bed. Preferably, the contacting step is carried out by passing an aqueous solution comprising a base and a chlorine salt through the fixed bed. Even more preferably, this passage through the fixed bed is carried out by circulation, preferably in a closed circuit. Preferably after the contacting step, the fixed bed undergoes a washing step, preferably with water.

[0061] It is therefore possible to directly convert objects made of amorphous aluminum hydroxide into objects made of lithium-bearing bayerite, without a shaping step. This conversion can advantageously be carried out directly in installations used to capture lithium from brines, particularly in adsorption columns.

[0062] In a particularly preferred variant of this first embodiment, more than 80%, preferably more than 90% by mass of the aluminum source is in the form of objects with dimensions of at least 0.2 mm, and the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is carried out at a temperature below 50°C, preferably below 40°C, preferably below 30°C, preferably less than or equal to 25°C, in particular is carried out at room temperature, the duration of contact being preferably greater than 60 minutes, preferably greater than 70 minutes, preferably greater than 80 minutes, preferably greater than 90 minutes, preferably greater than 100 minutes, preferably greater than 110 minutes, preferably greater than 120 minutes, preferably greater than 130 minutes, preferably greater than 140 minutes,preferably greater than 150 minutes, preferably greater than 160 minutes, and preferably less than 5 hours, preferably less than 4 hours, the molar ratio between the Cl supplied by said chlorine salt and the Al present in said aluminum source being preferably greater than 0.5. Contact may be made, in particular, by passing an aqueous solution comprising the base and the chlorine salt through a fixed bed made up of said objects.

[0063] A product obtained according to this preferred variant is in particular a product obtained by the process and which is in the form of objects having dimensions of at least 0.2 mm, and which do not include an organic binder, preferably which do not include a binder.

[0064] Another object of the invention is therefore a product comprising, and preferably is essentially made up of, or even made up of: - water, and - crystallites, at least a part, preferably all of said crystallites being made up of lithiated bayerite, the average size of the lithiated bayerite crystallites being greater than or equal to 2 nm and less than or equal to 25 nm, and said product having a cumulative rate of aluminium hydroxide and boehmite less than or equal to 10%, said product comprising at least the elements Li, Cl, Al, O and H, the elements Li, Cl and Al being present in said dry product in the following amounts, determined by inductively coupled plasma spectrometry, in weight percentages: - 2% < Li < 5%, - 10% < Cl < 26%, - 15% < Al < 30%.The average size of the lithiased bayerite crystallites and the cumulative content of aluminum hydroxide and boehmite are measured on the product after exposure to air for 170 hours at 25°C and atmospheric pressure. The product is in the form of objects with dimensions of at least 0.2 mm and does not contain any organic binder, preferably no binder at all. Preferably, the product has an average size of the lithiased bayerite crystallites greater than or equal to 2 nm and less than or equal to 6 nm. The various characteristics described above with respect to the product obtained by the process of the invention also apply to this product.

[0065] A product obtained according to this variant is also a product obtained by the process according to the invention and which is in the form of objects whose dimensions are at least 0.2 mm, and whose average size of the lithiated bayerite crystallites is greater than or equal to 2 nm and less than or equal to 6 nm, the average size of the lithiated bayerite crystallites being measured on said product after exposure to air for 170 hours at 25°C, at atmospheric pressure.

[0066] Another object of the invention is therefore a product comprising, and preferably is essentially made up of, or even made up of: - water, and - crystallites, at least a part, preferably all of said crystallites being made up of lithiated bayerite, the average size of the lithiated bayerite crystallites being greater than or equal to 2 nm and less than or equal to 6 nm, and said product having a cumulative rate of aluminium hydroxide and boehmite less than or equal to 10%, said product comprising at least the elements Li, Cl, Al, O and H, the elements Li, Cl and Al being present in said dry product in the following amounts, determined by inductively coupled plasma spectrometry, in weight percentages: - 2% < Li < 5%, - 10% < Cl < 26%, - 15% < Al < 30%.the average size of the lithiated bayerite crystallites and the cumulative content of aluminium hydroxide and boehmite being measured on said product after exposure to air for 170 hours at 25°C, at atmospheric pressure, said product being in the form of objects having dimensions of at least 0.2 mm. The various characteristics presented above relating to the product obtained by the process of the invention also apply to this product.

[0067] According to a second preferred variant of the first embodiment, the amorphous aluminum hydroxide included in the aluminum source is in the form of particles with dimensions less than 0.2 mm, preferably less than 0.1 mm, preferably in the form of a powder having a median diameter greater than 10 µm and preferably less than 20 µm.

[0068] Preferably, the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is carried out at a temperature below 50°C, preferably below 40°C, preferably below 30°C, preferably less than or equal to 25°C, in particular is carried out at room temperature, the molar ratio between the Cl supplied by said chlorine salt and the Al present in said aluminum source being preferably greater than 0.5. In one embodiment, the contacting step is carried out at a temperature below 20°C, preferably below 15°C, preferably below 10°C, preferably below 5°C, or even below 1°C.

[0069] The contacting step can be done in particular by suspending the aluminum source particles in an aqueous solution comprising the base and the chlorine salt and under agitation.

[0070] Preferably, the contact time is less than 30 minutes, preferably less than 20 minutes, preferably less than 10 minutes, preferably less than 6 minutes, and preferably more than 30 seconds, preferably more than 1 minute, preferably more than 2 minutes, preferably more than 3 minutes, preferably more than 4 minutes. The inventors were indeed able to demonstrate that in this second variant, the conversion of amorphous aluminum hydroxide into lithiated bayerite was exceptionally rapid, even at low temperatures.

[0071] Preferably, the possible complement to 100% by weight of the amorphous aluminium hydroxide present in the aluminium source has a median size less than or equal to 3 µm, preferably less than or equal to 2 µm, preferably less than or equal to 1 µm, preferably less than or equal to 0.7 µm, preferably less than or equal to 0.5 µm.

[0072] In addition to the advantages mentioned above, the first embodiment, regardless of the variant, allows for the production of particularly small crystallites. Lithiated bayerite crystallites have an average size between 2 and 25 nm, particularly between 2 and less than 10 nm, and even particularly between 2 and 8 nm, or even between 2 and 6 nm or between 6 and 8 nm.

[0073] Another object of the invention is therefore a product comprising, and preferably being essentially composed of, or even composed of: - water, and - crystallites, at least a part, preferably all of said crystallites being composed of lithiated bayerite, the average size of the lithiated bayerite crystallites being greater than or equal to 2 nm and less than or equal to 6 nm, and said product having a cumulative content of aluminum hydroxide and boehmite less than or equal to 10%, said product comprising at least the elements Li, Cl, Al, O, and H, the elements Li, Cl, and Al being present in said dry product in the following amounts, determined by inductively coupled plasma spectrometry, as weight percentages: - 2% < Li < 5%, - 10% < Cl < 26%, - 15% < Al < 30%, the average size of the lithiated bayerite crystallites and the cumulative content of aluminum hydroxide and boehmite being measured on said product after exposure to air for 170 hours at 25°C,at atmospheric pressure. The various characteristics presented above relating to the product obtained by the process of the invention also apply to this product.

[0074] According to a second embodiment (referred to as "second embodiment" in the following text), which differs from the first embodiment described above, the aluminum source comprises less than 90% amorphous aluminum hydroxide, the amorphous aluminum hydroxide in the aluminum source is in the form of particles with dimensions less than 0.2 mm, and the step of contacting the solution comprising the chlorine salt is carried out at a temperature greater than or equal to 50°C and less than or equal to 60°C, the duration of contact being between 45 minutes and 15 hours.

[0075] Preferably, the aluminum source comprises more than 20%, preferably more than 30%, preferably more than 40%, preferably more than 50%, preferably more than 60%, preferably more than 70%, preferably more than 80%, by mass of amorphous aluminum hydroxide.

[0076] Preferably, the amorphous aluminium hydroxide in the aluminium source is in the form of particles with dimensions less than 0.1 mm, preferably less than 50 µm, preferably less than 20 µm, or even less than 10 µm, or even less than 5 µm, or even less than 3 µm, or even less than 1 µm, preferably is in the form of a powder with a median size greater than 10 µm and less than 20 µm, and the complement to 100% by weight of the amorphous aluminium hydroxide present in the aluminium source has a median size less than or equal to 3 µm, preferably less than or equal to 2 µm, preferably less than or equal to 1 µm, preferably less than or equal to 0.7 µm, preferably less than or equal to 0.5 µm.

[0077] Preferably, in the second embodiment, the contact time is greater than 50 minutes, preferably greater than 55 minutes, and preferably greater than 1 hour. In one embodiment, the contact step is carried out at a temperature of 50°C, and the contact time is less than 15 hours, preferably less than 10 hours, preferably less than 7 hours, and preferably greater than 3 hours. In one embodiment, the contact step is carried out at a temperature of 60°C, and the contact time is less than 3 hours, preferably less than 2 hours, preferably less than 1.5 hours, and preferably greater than 1 hour.

[0078] In addition to the advantages mentioned above, the second embodiment allows for the production of particularly small crystallites. Lithiated bayerite crystallites have an average size between 10 and 25 nm, particularly between 10 and 23 nm, and especially between 10 and 20 nm.

[0079] In the second variant of the first embodiment and in the second embodiment previously described, the presence of amorphous aluminum hydroxide makes it possible to obtain a product with a waxy appearance, different from the products obtained from crystallized aluminum hydroxide, which are in the form of pastes or creams.

[0080] Regardless of the embodiment, except when the aluminum source consists of amorphous aluminum hydroxide, the aluminum source may include crystalline aluminum hydroxide and / or boehmite having a median size less than or equal to 3 µm, preferably less than or equal to 2 µm, preferably less than or equal to 1 µm, preferably less than or equal to 0.7 µm, preferably less than or equal to 0.5 µm.

[0081] The process may further include, in particular and preferably in the second variant of the first embodiment and in the second embodiment previously described, after the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt, an acidification step.

[0082] The acidification step is carried out after the aluminum source has been contacted with the aqueous solution containing a base and with the aqueous solution containing a chlorine salt. However, this does not imply that the aluminum source is not in contact with these solutions during the acidification step.

[0083] Preferably, the step of contacting the aluminum source with the aqueous solution comprising a base and with an aqueous solution comprising a chlorine salt is carried out by suspension, preferably under stirring, and the acidification step comprises the addition of an acid so as to decrease the pH of the suspension to a value less than or equal to 8, preferably less than or equal to 7, preferably less than or equal to 6, preferably less than or equal to 5, preferably less than or equal to 4, preferably less than or equal to 3, preferably less than or equal to 2, said chlorine salt, said acid, and their respective amounts being chosen so that the Cl / Al molar ratio in the suspension is greater than or equal to 0.5, and preferably less than or equal to 3. In a preferred embodiment, the pH of the suspension is adjusted to a value equal to 2.Preferably, said acid is chosen from HCl, H2SO4, HNO3, HI, HBr, HClO4, HClO3, HMnO4, H2MnO4 and mixtures thereof, preferably from HCl, HNO3, HBr, HClO4, HClO3 and mixtures thereof. Preferably the acid is HCl.

[0084] The process may further include, after the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt, a filtration step.

[0085] This filtration step is preferably carried out after any acidification step. The filtration step is preferably carried out in the second variant of the first embodiment and in the second embodiment described above. For example, the step of contacting the aluminum source with the aqueous solution comprising the base and the chlorine salt is carried out by stirring the mixture into a suspension, and the filtration step consists of filtering this suspension. The filtration step can be carried out using any known filtration technique, in particular with a filter press, centrifuge, belt filter, drum filter, screen, or sieve.

[0086] The process preferably includes a washing step. This applies in particular to both the first and second embodiments. When the process includes an acidification step, the washing step serves, in particular, to remove any acid that may have been added to the process before any shaping.

[0087] The washing step is preferably carried out after the filtration step. It is preferably performed with water or an aqueous solution having a total ion concentration of less than 2 g / l. In a preferred embodiment, water at room temperature is used for this washing step. The washing time may be greater than 1 minute, preferably greater than 2 minutes, preferably greater than 3 minutes, preferably greater than 4 minutes, preferably greater than 5 minutes, and preferably less than 30 minutes, preferably less than 25 minutes, preferably less than 20 minutes, preferably less than 15 minutes, preferably less than 10 minutes.

[0088] Preferably, in the entirety of the first embodiment of the process, the temperature is below 50°C, preferably below 40°C, preferably below 30°C, and most preferably the temperature is ambient temperature, including in the optional acidification, filtration, and washing steps. In one embodiment, in the entirety of the first embodiment of the process, the temperature is below 20°C, preferably below 15°C, preferably below 10°C, preferably below 5°C, or even below 1°C.

[0089] The process may further include, after the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt, and after an optional acidification and / or filtration and / or washing step, a shaping step into the form of an object. The shaping step includes the shaping of a filler.

[0090] This is particularly the case for the second variant of the first embodiment and the second embodiment, or more generally when the amorphous aluminum hydroxide in the aluminum source is in the form of particles with dimensions less than 0.2 mm, preferably less than 0.1 mm, preferably in the form of a powder with a median diameter greater than 10 µm and preferably less than 20 µm, and the crystalline aluminum hydroxide and / or boehmite possibly included in the aluminum source has a median size less than or equal to 3 µm, in particular less than or equal to 1 µm. In these cases, the product obtained after the step of contacting the base and the chlorine salt and the possible filtration step is in the form of a waxy product.

[0091] The shaping stage then includes shaping a charge comprising, preferably consisting of, this waxy product. This shaping can be carried out using any technique known to those skilled in the art, for example extrusion, granulation, pressing, casting, atomization, screen printing, tape casting, or drip casting.

[0092] According to a first embodiment, the filler comprises a binder, preferably an organic binder, preferably a polysaccharide comprising a group capable of forming an ionic bond with a gelling agent for the formation of a gelled polysaccharide. This first embodiment is not preferred because the use of amorphous aluminum hydroxide in the process of the invention eliminates the need for a binder.

[0093] According to a second variant, the filler does not contain a binder, in particular no organic binder. Furthermore, preferably the filler does not contain acid. It has been found that excellent attrition resistance can be achieved with the invention, even in the absence of a binder or acid.

[0094] The filler may also include a solvent and / or a plasticizer and / or a lubricant, the nature and quantity of which are adapted to the shaping method. Preferably, the solvent is water. The quantity of solvent is adapted to the shaping process used. In one embodiment, particularly when the filler contains an excessive amount of solvent, preferably water, relative to the intended shaping process, a step to remove some of the solvent may be carried out. Preferably, however, the filler does not include any solvent other than water, nor does it include any plasticizer or lubricant. The filler advantageously consists of the waxy product, without any additives, in particular without the addition of a binder or acid.

[0095] The objects obtained after shaping can be in the form of cylinders, polylobes, rings, or spheres, all of which preferably have dimensions less than 1.5 mm.

[0096] The invention also relates to a lithium capture device, in particular an extraction column, comprising a product according to the invention or a product obtained by the process according to the invention as described above. In the device, the product is generally in the form of objects having dimensions of at least 0.2 mm as described above.

[0097] Examples

[0098] The amount of amorphous phase of the aluminium sources used in the examples, as a percentage by mass based on the mass of said aluminium source, is determined by X-ray diffraction using the following method.

[0099] After exposure to air for 170 hours at 25°C, at atmospheric pressure, the aluminum source is deagglomerated using an agate mortar.

[0100] The diffraction pattern was acquired using a Bruker D8 Endeavor instrument equipped with a copper DX tube, over an angular range 2θ from 14° to 100°, with a step size of 0.01° and a counting time of 0.34 s / step. The front optics included a fixed 0.3° divergence slit, a 2.5° Soller slit, and a knife-edge filter in automatic mode. The rear optics included a 2.5° Soller slit, a 0.0125 mm nickel filter, and a 1D detector with a 4° aperture.

[0101] The quantity of amorphous phase, expressed as a percentage based on the mass of the product, is classically defined as the ratio 100 x (A T -HAS P ) / HAS T , HAS T being the area under the diffraction pattern and A Pbeing the sum of the areas of each diffraction peak present on the diffraction pattern, the unit of the y-axis of said diffraction pattern being counts per second, and the unit of the x-axis being degrees. For the calculation of this ratio, a diffraction peak is considered to be a peak whose total height-to-width ratio is greater than or equal to 3 counts / (second x degree). If the diffraction pattern does not show any such diffraction peaks, the product is considered to have 100% amorphous phase.

[0102] The nature of the crystalline phases of the sample objects is determined by the following classical method: The sample products are first exposed to air for 170 hours at 25°C and atmospheric pressure. Acquisitions are performed using a Bruker D8 Endeavor instrument equipped with a copper DX tube, over an angular range 2θ between 5° and 80°, with a step size of 0.017° and a counting time of 300 s / step. The front optics include a fixed 0.25° divergence slit, a 0.02 rad Soller slit, a 10 mm mask, and a fixed 0.5° anti-scattering slit. The sample is rotated. The rear optics include a fixed 0.25° anti-scatter slit, a 0.02 rad Soller slit, and a nickel filter. The diffraction patterns are then qualitatively analyzed using EVA software and the ICDD2016 database.The PDF data sheet 00-031-0700 from the ICDD2016 database allows the identification of the phase (LiCl).2Al(OH)3, xH2O. The crystallized phase of lithiated bayerite shown may exhibit a slight angular shift of the peaks compared to the said data sheet, a consequence in particular of the amount of Li inserted in the structure of the lithiated bayerite.

[0103] The average size of the lithiated bayerite crystallites, D, of the products of the examples is classically determined by X-ray diffraction on a powder of said product, previously exposed to air for 170 hours at 25°C, at atmospheric pressure, using a D8 Endeavor type apparatus from the Bruker company, with the following Debye-Scherrer equation:

[0104]

[0105] - K being equal to 0.89,- λ being the wavelength of X-rays, here equal to that of copper, i.e. 1.54 Angstroms, B being the full width at half maximum of the peak of the (003) plane of the lithiated bayerite (PDF data sheet 00-031-0700 from the ICCD database), in degrees,- b being the full width at half maximum of the peak of the single-crystal silicon standard used, here measured equal to 0.05°, and- 2θ being the angle of the maximum intensity of the peak corresponding to the (003) plane of the lithiated bayerite, in degrees.

[0106] The diffraction patterns of the single-crystal silicon standard and the sample were acquired over an angular range 2θ between 5° and 80°, with a step size of 0.017°, and a counting time of 300 s / step for the sample and 100 s / step for the single-crystal silicon standard. The front optics consisted of a fixed 0.25° divergence slit, a 0.02 rad Soller slit, a 10 mm mask, and a fixed 0.5° anti-scattering slit. The sample was rotated. The rear optics consisted of a fixed 0.25° anti-scattering slit, a 0.02 rad Soller slit, and a nickel filter.

[0107] After eliminating the Kα2 line, the full width at half maximum of the peaks is determined using the EVA software, and the average size of the lithiated bayerite crystallites is determined using the FWHM function.

[0108] The cumulative concentration of aluminum hydroxide and boehmite was determined using the same X-ray diffraction patterns employed to identify the crystalline phases present. After eliminating the Kα2 line and using EVA software, it is possible to measure area A HA of the aluminum hydroxide diffraction peak present in an angular domain 2θ approximately equal to 18.3°, the area A BO the diffraction peak of boehmite located in an angular domain 2θ approximately equal to 14°, and the area A BL the diffraction peak of the lithia-treated bayerite is located in an angular domain 2θ approximately equal to 11.3°. The cumulative content of aluminum hydroxide and boehmite is then calculated according to formula (1) given previously:

[0109] T = 100* (A HA + A BO ) / (HAS HA + A BO + A BL (1)

[0110] Thus, when the product does not contain aluminum hydroxide or boehmite, the cumulative level of aluminum hydroxide and boehmite is equal to 0.

[0111] With the exception of the elements O and H, the contents of the different elements present in the products of the examples are determined, on products dried under air at 200°C for 16 hours, at atmospheric pressure, by inductively coupled plasma spectrometry (or "ICP" in English), using an Agilent 5800 ICP-OES instrument.

[0112] The water content is determined as the mass loss, expressed as a percentage, after drying in air at 200°C for 16 hours, at atmospheric pressure. After such drying, the product is said to be "dry".

[0113] The median size of a powder or suspension is measured using a LA950V2 laser particle size analyzer marketed by the company Horiba.

[0114] The attrition resistance of a powder of objects is determined using the following method.

[0115] For each of examples 1 to 3, and 8 after shaping by granulation, 5 g of the powder of the example are washed with 100 ml of demineralized water.

[0116] Then a brine is made by dissolving LiCl, NaCl, KCl, CaCl2,2H2O, MgCl2,6H2O and H3BO3 in water so as to obtain the concentrations of Li, Na, K, Ca, Mg, B and Cl shown in the following table 1.

[0117] Elements / Concentration in mg / l of brine: Li 350, Na 50000, K 5000, Ca 10000, Mg 500, B 1000, Cl 100000

[0118] The pH of the brine is then adjusted, if necessary, to a value of 5 by adding hydrochloric acid.

[0119] Then the washed powder and 50 ml of said brine are placed in a plastic pot with a diameter of 50 mm and a height of 70 mm.

[0120] The plastic container is then firmly fixed inside a jar with an internal volume of 3 liters and an internal diameter of 13 cm. The jar is then rotated on a jar turner at a speed of 80 revolutions per minute for 20 minutes.

[0121] Then, the turbidity of the brine is measured using a model 2100N turbidimeter from the company HACH, said turbidimeter being switched on at least 30 minutes before taking the measurement in order to stabilize the intensity of the light emitted, said turbidimeter being also calibrated before measurement in the range of 0 to 1000 NTU (Nephelometric Turbidity Units) using at least 4 standard calibration liquids.

[0122] Turbidity provides information about the example's resistance to attrition. The lower the turbidity, the greater the example's resistance to attrition.

[0123] The lithium adsorption capacity of the examples is determined using the following method.

[0124] The brine used in this method is identical to that described previously and used to determine attrition resistance.

[0125] 500 ml of demineralized water is introduced into a double-jacketed reactor. Stirring is then started at a speed of 200 rpm. Next, 30 g of the sample is added to the reactor, and stirring is maintained for 10 minutes. A sample is then taken to determine the lithium concentration after filtration with a syringe filter. The lithium concentration is adjusted to 120 mg / l if necessary by adding more demineralized water. The solution is then filtered using a Büchner funnel with grade 393 filter paper to obtain a paste for Example 4 and a waxy product for Examples 6 to 8. A quantity of paste for Example 4 and waxy product for Examples 6 to 8, corresponding to 5 g of dry product, is introduced into the previously emptied and washed double-jacketed reactor. Then a volume V equal to 0.3 l of brine is added to the reactor, the brine having a lithium concentration, L iequal to 350 mg / l. The mixture is stirred at a rotation speed of 200 rpm for 60 minutes. A sample is then taken to determine, after filtration with a syringe filter, the lithium concentration (Li). f , in mg / l. The lithium adsorption capacity, C, in mg of lithium per g of dry sample, is calculated using the following formula: C = 0.3 x (Li i -Li f ) / 5.

[0126] Manufacturing protocol

[0127] The following raw materials were used for the examples: - Amorphous aluminum hydroxide powder with 100% amorphous phase, less than 3.5% content of elements other than Al, O, and H, and a median particle size of 16.7 µm for examples 5 to 8; - Amorphous aluminum hydroxide granule powder with 100% amorphous phase, less than 3.5% content of elements other than Al, O, and H, and a median particle size of 560 µm for examples 2 and 3; - Al(OH)3 gibbsite powder with a median particle size of 1.6 µm and a purity greater than 99.5% by mass for examples 1 and 4; - Lithium hydroxide monohydrate (LiOH·H2O) with a purity greater than 99.5% by mass for examples 1 to 8. Lithium chloride (LiCl), with a purity greater than 99.5% by mass, for examples 1 to 8. Hydrochloric acid (HCl), with a purity greater than 99% by mass, in an aqueous solution at 16% by mass.For examples 1 and 4 to 8, - An ammonium alginate of purity greater than 99% by mass, for example 1.

[0128] The product of example 1, outside the scope of the invention, was obtained in the following manner.

[0129] Four kg of gibbsite (crystallized aluminum hydroxide) are added to 20 L of water in a double-jacketed reactor at a temperature of 25°C. The reactor is connected to an LME4 mill marketed by Netzsch. The gibbsite-water suspension is ground for 75 minutes. Once the mill is stopped and emptied, the gibbsite suspended in the water in the reactor has a median particle size of 0.55 μm.

[0130] Then, LiOH and H₂O are added to the reactor such that the molar ratio of the OH⁻ from LiOH to the Al initially present in the reactor is 0.5. The mixture is stirred for 5 minutes at a temperature of 25°C. Next, LiCl is added so that the molar ratio of the Cl⁻ from LiCl to the Al initially present in the mixture is 1. The mixture is stirred for another 5 minutes at a temperature of 25°C. The Li / Al molar ratio is 1.5.

[0131] The mixture is then heated to 60°C for 15 minutes at a temperature of 50°C or higher. It is then maintained at 60°C for 75 minutes. HCl is then added to lower the pH to 7, resulting in a Cl / Al molar ratio of 1.6. The mixing time is maintained at 60°C for another 15 minutes. Finally, the resulting mixture is filtered using a filter press at room temperature (below 50°C) with 1 μm permeability cloths to obtain a paste. During filtration, the mixture is held at a temperature of 50°C or higher for 5 minutes.

[0132] The resulting paste has the consistency of a cream, is not cohesive and exhibits the characteristics shown in Table 2 below.

[0133] Quantity of water, by mass percentage: 65% Crystalline phase detected: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites (nm): 21.5 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 4.1 Cl content (%): 20.5 Al content (%): 18.7 Contents of elements other than Li, Al, Cl, O and H (%): 0.1 O and H (%): Complement to 100

[0134] After cooling the paste, a filler was then made by mixing the obtained paste and ammonium alginate, the content of said alginate being equal to 1% by mass on the basis of the mass of the filler, measured after drying at 200°C for 16 hours.

[0135] The feed was then shaped by granulation using the following process. A 3 kg quantity of feed was placed in an R02 mixer marketed by Eirich, the mixer being equipped with a star-type rotor agitator. The drum and the agitator were rotated in a counter-rotating direction, with the agitator speed set at 300 rpm and the drum speed set to position 2, for 1 hour under a hot air flow at 200°C. The mixer and the hot air flow were then switched off, and the agitator was removed and replaced with a microgranulation blade.The mixer is then restarted, with the drum and micro-granulation blade rotating in opposite directions. The rotation speed of the agitation blade is set to 1500 revolutions per minute, and the drum speed is set to position 2. The micro-granulation blade's rotation speed is maintained for 1 minute to granulate the material. The mixer is then stopped.

[0136] At the end of the said granulation process, a powder of particles is obtained having an equivalent diameter between 0.05 mm and 4 mm, exhibiting the characteristics shown in the following table 3.

[0137] Quantity of water, by mass percentage: 30% Crystalline phases identified: Lithiated bayerite, traces of NaCl Cumulative levels of aluminum hydroxide and boehmite (%): 0 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 3.7 Cl content (%): 18.5 Al content (%): 25.7 Contents of elements other than Li, Al, Cl, O and H (%): 0.1 Elements O and H (%): Complement to 100

[0138] The powder of example 1, outside the invention, is obtained after sieving the powder obtained at the end of the granulation process, said powder of example 1 being the residue on a square mesh sieve with an opening of 0.3 mm and the passing on a square mesh sieve with an opening of 1.2 mm.

[0139] The product of example 2, according to the invention, manufactured according to a process conforming to variant 1 of the first embodiment described above, was obtained in the following manner.

[0140] 50 g of amorphous aluminium hydroxide granules are poured into a double-jacketed glass column with a height of 30 cm and a diameter of 25.4 mm.

[0141] A mixture of lithium hydroxide monohydrate, lithium chloride and 242 g of water is prepared in a double-jacketed reactor, the molar ratio between the OH supplied by (LiOH, H2O) and the Al supplied by the granules of amorphous aluminium hydroxide being equal to 0.5, the molar ratio between the Cl supplied by LiCl and the Al supplied by the granules of amorphous aluminium hydroxide being equal to 1, and the molar ratio Li / Al being equal to 1.5.

[0142] Then the said mixture is put into closed circulation, using two peristaltic pumps, through the glass column containing the granules of amorphous aluminum hydroxide, the granules of amorphous aluminum hydroxide and the mixture of lithium hydroxide monohydrate, lithium chloride and water being at room temperature (22°C).

[0143] The circulation of the mixture of lithium hydroxide monohydrate, lithium chloride and water is then stopped, and said mixture is extracted from the column by filtration through a porous ceramic sieve: the contact time is equal to 165 minutes.

[0144] The granules then undergo a 5-minute washing step carried out by closed-loop circulation of 120 ml of water.

[0145] The granules recovered after washing have the characteristics shown in Table 4 below.

[0146] Quantity of water, by mass percentage: 61% Crystallized phases identified: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites: 7.1 nm Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 4.4 Cl content (%): 22.2 Al content (%): 25.3 Contents of elements other than Li, Al, Cl, O and H (%): < 1 Elements O and H (%): Complement to 100

[0147] The product of Example 3, according to the invention, manufactured according to a process in accordance with variant 1 of the first embodiment described above, was obtained in the same way as Example 2, with the following differences: the mixture of lithium hydroxide monohydrate, lithium chloride and water is brought to a temperature of 60°C in the double-jacketed reactor, and the temperature of the granules of amorphous aluminum hydroxide and of the mixture of lithium hydroxide monohydrate, lithium chloride and water is 60°C for the entire duration of the contact, and the duration of the contact, carried out at a temperature of 60°C, is 125 minutes.

[0148] The granules recovered after washing have the characteristics shown in the following table 5.

[0149] Quantity of water, by mass percentage: 60% Crystallized phases identified: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites: 7.5 nm Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 4.2 Cl content (%): 21.4 Al content (%): 25.6 Contents of elements other than Li, Al, Cl, O and H (%): < 0.1 O and H elements (%): Complement to 100

[0150] An infrared spectroscopy analysis of examples 2 and 3 did not reveal the presence of aluminium hydroxide.

[0151] An attrition resistance test was then performed on each of examples 1 to 3 according to the protocol described above. The results obtained are shown in Table 6 below.

[0152] Turbidity after attrition test (UNT) Example 1279 Example 236 Example 382

[0153] The turbidity measured after attrition testing of examples 2 and 3 according to the invention, equal to 36 UNT and 82 UNT, respectively, is lower than that of example 1 outside the invention, equal to 279 UNT: the turbidity of example 2 is 7.75 times lower than that of example 1 and the turbidity of example 3 is 3.4 times lower than that of example 1. The resistance to attrition of examples 2 and 3 according to the invention is much greater than that of example 1 outside the invention: their lifespan is longer.

[0154] Examples 1 to 3 also exhibit a high lithium adsorption capacity.

[0155] The product of example 4, outside the scope of the invention, was obtained in the following manner.

[0156] Four kg of gibbsite are added to 20 L of water in a double-jacketed reactor at a temperature of 25°C. The reactor is connected to an LME4 mill marketed by Netzsch. The gibbsite-water suspension is ground for 75 minutes. Once the mill is stopped and emptied, the gibbsite suspended in the water in the reactor has a median particle size of 0.55 μm.

[0157] Then, LiOH and H₂O are added to the reactor such that the molar ratio of the OH⁻ from LiOH to the Al initially present in the reactor is 0.5. The mixture is stirred for 15 minutes at a temperature of 25°C. Next, LiCl is added so that the molar ratio of the Cl⁻ from LiCl to the Al initially present in the mixture is 1. The mixture is stirred for another 15 minutes at a temperature of 25°C. The Li / Al molar ratio is 1.5.

[0158] The mixture is then heated to 60°C for 15 minutes at a temperature of 50°C or higher. It is then held at 60°C for 10 minutes. Next, HCl is added to lower the pH to 3, resulting in a Cl / Al molar ratio of 1.6. The mixing time is 5 minutes, and the temperature is maintained at 60°C. Finally, the resulting mixture is filtered at room temperature using a filter press with 1 μm permeability cloths to obtain a paste. During filtration, the mixture is held at a temperature of 50°C or higher for 5 minutes.

[0159] The resulting paste has the consistency of a cream, is not very cohesive and exhibits the characteristics shown in Table 7 below.

[0160] Quantity of water, by mass percentage: 65% Crystallized phase detected: Lithiated bayerite, gibbsite Cumulative percentage of aluminum hydroxide and boehmite (%): 30 Average size of lithied bayerite crystallites (nm): 18.2 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 3.1 Cl content (%): 16 Al content (%): 20.5 Contents of elements other than Li, Al, Cl, O and H (%): 0.1 Elements O and H (%): Complement to 100

[0161] The product of example 5, according to the invention, manufactured according to a process conforming to variant 2 of the first embodiment described above, was obtained in the following manner.

[0162] 4 kg of amorphous aluminium hydroxide with a median size of 16.7 µm are added to 20 l of water in a double-jacketed reactor, at a temperature of 25°C.

[0163] Then the suspension of amorphous aluminum hydroxide is heated to 60°C.

[0164] Then, LiOH and H₂O are added to the reactor such that the molar ratio of the OH⁻ from LiOH to the Al initially present in the reactor is 0.5. The mixture is stirred for 30 seconds, with the reactor temperature maintained at 60°C. Next, LiCl is added so that the molar ratio of the Cl⁻ from LiCl to the Al initially present in the mixture is 1. The mixture is stirred for 30 minutes, with the reactor temperature maintained at 60°C. The Li / Al molar ratio is 1.5.

[0165] Then, HCl is added to the mixture, lowering its pH to 2. The Cl / Al molar ratio in the mixture after the addition of HCl is 1.8, the mixing time is 5 minutes, the temperature is reduced below 50°C, and the mixture is held at or above 50°C for 2 minutes. Finally, the resulting mixture is filtered at room temperature using a filter press with 1 μm permeability cloths to obtain a waxy product. In this example, the contact time is 30 minutes.

[0166] The waxy product thus obtained is much more cohesive than the creamy pastes of comparative examples 1 and 4, despite having an equivalent water content. It exhibits the characteristics shown in Table 8 below.

[0167] Quantity of water, by mass percentage: 63% Crystallized phase detected: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites (nm): 9.8 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 3.8 Cl content (%): 19.0 Al content (%): 26.6 Contents of elements other than Li, Al, Cl, O and H (%): < 0.1 O and H (%): Complement to 100

[0168] The product of example 6, according to the invention, manufactured according to a process conforming to variant 2 of the first embodiment described above, was obtained in the following manner.

[0169] Four kilograms of amorphous aluminum hydroxide with a median particle size of 16.7 µm are added to 20 liters of water in a double-jacketed reactor at a temperature of 25°C. The amorphous aluminum hydroxide-water suspension is ground for 75 minutes. Once the grinder is stopped and the reactor is emptied, the amorphous aluminum hydroxide suspended in the water in the reactor has a median particle size of 0.7 µm.

[0170] Then the suspension of amorphous aluminium hydroxide is then heated to 60°C.

[0171] Then, LiOH and H₂O are added to the reactor such that the molar ratio of the OH⁻ from LiOH to the Al initially present in the reactor is 0.5. The mixture is stirred for 30 seconds, with the reactor temperature maintained at 60°C. Next, LiCl is added so that the molar ratio of the Cl⁻ from LiCl to the Al initially present in the mixture is 1. The mixture is stirred for 30 minutes, with the reactor temperature maintained at 60°C. The Li / Al molar ratio is 1.5.

[0172] Then, HCl is added to the mixture, lowering its pH to 2. The Cl / Al molar ratio in the mixture after the addition of HCl is 1.8, the mixing time is 5 minutes, and the temperature is reduced below 50°C. The time during which the mixture is at a temperature of 50°C or higher is 2 minutes. Finally, the resulting mixture is filtered at room temperature using a filter press with 1 μm permeability to obtain a waxy product. For this example, the contact time is 30 minutes.

[0173] The waxy product thus obtained has the characteristics shown in the following table 9.

[0174] Quantity of water, by mass percentage: 70% Crystalline phase detected: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites (nm): 16.6 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 3.9 Cl content (%): 19.3 Al content (%): 26.5 Contents of elements other than Li, Al, Cl, O and H (%): < 0.1 O and H (%): Complement to 100

[0175] The product of Example 7, according to the invention, manufactured according to a process conforming to variant 2 of the first embodiment described above, was obtained in the following manner.

[0176] Four kilograms of amorphous aluminum hydroxide with a median particle size of 16.7 µm are added to 20 liters of water in a double-jacketed reactor at a temperature of 25°C. The amorphous aluminum hydroxide-water suspension is ground for 75 minutes. Once the grinder is stopped and the reactor is emptied, the amorphous aluminum hydroxide suspended in the water in the reactor has a median particle size of 0.7 µm.

[0177] Then the suspension of amorphous aluminium hydroxide is then heated to 60°C.

[0178] Then, LiOH and H₂O are added to the reactor such that the molar ratio of the OH⁻ from LiOH to the Al initially present in the reactor is 0.5. The mixture is stirred for 30 seconds, with the reactor temperature maintained at 60°C. Next, LiCl is added so that the molar ratio of the Cl⁻ from LiCl to the Al initially present in the mixture is 1. The mixture is stirred for 5 minutes, with the reactor temperature maintained at 60°C. The Li / Al molar ratio is 1.5.

[0179] Then, HCl is added to the mixture, lowering its pH to 2. The Cl / Al molar ratio in the mixture after the addition of HCl is 1.8, the mixing time is 5 minutes, and the temperature is reduced below 50°C during this step. The mixture is held at or above 50°C for 2 minutes. Finally, the resulting mixture is filtered at room temperature using a filter press with 1 μm permeability to obtain a waxy product. For this example, the contact time is 5 minutes.

[0180] The waxy product thus obtained has the characteristics shown in the following table 10.

[0181] Quantity of water, by mass percentage: 70% Crystalline phase detected: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites (nm): 14.5 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 3.5 Cl content (%): 17.5 Al content (%): 27.3 Contents of elements other than Li, Al, Cl, O and H (%): < 0.1 O and H (%): Complement to 100

[0182] The product of example 8, according to the invention, manufactured according to a process in accordance with variant 2 of the first embodiment described above, was obtained in the following manner.

[0183] Four kilograms of amorphous aluminum hydroxide with a median particle size of 16.7 µm are added to 20 liters of water in a double-jacketed reactor at a temperature of 25°C. The amorphous aluminum hydroxide-water suspension is ground for 75 minutes. Once the grinder is stopped and the reactor is emptied, the amorphous aluminum hydroxide suspended in the water in the reactor has a median particle size of 0.7 µm.

[0184] Then, LiOH and H₂O are added to the reactor such that the molar ratio of the OH⁻ from LiOH to the Al initially present in the reactor is 0.5. The mixture is stirred for 30 seconds, with the reactor temperature maintained at 25°C. Next, LiCl is added so that the molar ratio of the Cl⁻ from LiCl to the Al initially present in the mixture is 1. The mixture is stirred for 5 minutes, with the reactor temperature maintained at 25°C. The Li / Al molar ratio is 1.5.

[0185] Then, HCl is added to the mixture, lowering its pH to 2. The Cl / Al molar ratio in the mixture after the addition of HCl is 1.8, the mixing time is 30 seconds, and the temperature is maintained at 25°C. Finally, the resulting mixture is filtered at room temperature using a filter press with 1 μm permeability cloths to obtain a waxy product. For this example, the contact time is 5 minutes.

[0186] The waxy product thus obtained has the characteristics shown in the following table 11.

[0187] Quantity of water, by mass percentage: 70% Crystallized phase detected: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites (nm): 7.2 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 3.4 Cl content (%): 16.8 Al content (%): 27.5 Contents of elements other than Li, Al, Cl, O and H (%): < 0.1 O and H (%): Complement to 100

[0188] A comparison of examples 4 outside the invention, and 5 and 6 according to the invention shows that the products of examples 5 and 6 made according to a process according to the invention having a contact time of 30 minutes and 5 minutes respectively, at 60°C have a cumulative rate of aluminium hydroxide and boehmite equal to 0 unlike product 4, outside the invention, made according to a process with a contact time of 35 minutes at 60°C.

[0189] Example 8 shows that the process according to the invention in which the contact is made at 25°C and for a time of 5 minutes also makes it possible to obtain a product having a cumulative rate of aluminium hydroxide and boehmite equal to 0.

[0190] An infrared spectroscopy analysis of examples 5 to 8 did not reveal the presence of aluminum hydroxide.

[0191] A lithium adsorption capacity measurement was then performed on each of examples 5 to 8 according to the protocol described above. The results obtained are shown in Table 12 below.

[0192] Lithium adsorption capacity (mg Li / g of adsorbent) Example 59.2 Example 68.9 Example 711.7 Example 810.8

[0193] The lithium adsorption capacity of the products in examples 5 to 8 is high: these products are well suited for use as lithium adsorbents after shaping.

[0194] The consistency of the waxy products in examples 5 to 8 is much more cohesive than that of the creamy products in comparative examples 1 and 4.

[0195] After cooling, the waxy product of Example 8 was then shaped using the same granulation process as that used to shape Example 1 outside the scope of this invention, except that no ammonium alginate was added to the filler. The filler therefore contained no binder, and the resulting objects consisted of water and crystallites.

[0196] At the end of the said granulation process, a powder of particles is obtained having an equivalent diameter between 0.05 mm and 4 mm, and having the characteristics shown in the following table 13.

[0197] Quantity of water, by mass percentage: 28% Crystalline phase detected: Lithiated bayerite Cumulative percentage of aluminum hydroxide and boehmite (%): 0 Average size of lithied bayerite crystallites (nm): 7.5 Chemical analysis by inductively coupled plasma spectrometry, after drying in air at 200°C for 16 hours, by weight percentage: Li content (%): 3.8 Cl content (%): 17.2 Al content (%): 25.9 Contents of elements other than Li, Al, Cl, O and H (%): < 0.1 O and H (%): Complement to 100

[0198] An attrition resistance test was then carried out, according to the protocol described above, after sieving the said particle powder so as to use in the test a particle powder corresponding to the residue on a 0.3 mm square mesh sieve and the residue passing on a 1.2 mm square mesh sieve. The results obtained are shown in Table 14 below.

[0199] Turbidity after attrition test (UNT) Example 1279 Example 866

[0200] The turbidity measured after the attrition test of Example 8, after shaping, was 66 UNT, which is lower than that of Example 1 (outside the scope of the invention), which was 279 UNT: the turbidity of Example 8 is 4.2 times lower than that of Example 1. The attrition resistance of Example 8 after shaping is significantly higher than that of Example 1 (outside the scope of the invention). Achieving such attrition resistance despite the absence of a binder is particularly surprising.

Claims

A process for manufacturing a product comprising a lithium bayerite, said process comprising a step of contacting an aluminum source consisting of an aluminum hydroxide or consisting of an aluminum hydroxide and boehmite, said aluminum source comprising at least 10% by weight of an amorphous aluminum hydroxide, with a) an aqueous solution comprising a base, such that the molar ratio between the OH supplied by said base and the Al present in said aluminum source is greater than 0.20, and b) an aqueous solution comprising a chlorine salt, such that the molar ratio between the Cl supplied by said chlorine salt and the Al present in said aluminum source is greater than 0.25; said base and / or said chlorine salt comprising lithium, and their respective amounts being chosen so as to supply an amount of lithium such that the Li / Al molar ratio is greater than or equal to 1. A method according to claim 1, wherein the aluminum source is brought into contact with an aqueous solution comprising both said base and said chlorine salt. A process according to any one of the preceding claims, wherein the aluminum source comprises at least 90% by weight of amorphous aluminum hydroxide. A method according to the preceding claim, wherein the step of bringing the aluminium source into contact with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt is carried out at a temperature below 50°C, in particular is carried out at room temperature. A method according to the preceding claim, wherein at least a portion of the amorphous aluminum hydroxide present in the aluminum source is in the form of objects with dimensions of at least 0.2 mm. A method according to any one of claims 1 to 4, wherein the amorphous aluminum hydroxide included in the aluminum source is in the form of particles having dimensions less than 0.2 mm. A process according to any one of claims 1 or 2, wherein the aluminum source comprises less than 90% amorphous aluminum hydroxide, wherein the amorphous aluminum hydroxide included in the aluminum source is in the form of particles having dimensions less than 0.2 mm, and wherein the step of contacting the solution comprising the chlorine salt is carried out at a temperature greater than or equal to 50°C and less than or equal to 60°C, the duration of contact being between 45 minutes and 15 hours. A process according to any one of the preceding claims, further comprising, after the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt, an acidification step. A method according to the preceding claim, wherein the step of contacting the aluminum source with the aqueous solution comprising a base and with an aqueous solution comprising a chlorine salt is carried out by suspension, and the acidification step comprises the addition of an acid so as to decrease the pH of the suspension to a value less than or equal to 3, said chlorine salt, said acid, and their respective quantities being chosen so that the molar ratio Cl / Al in the suspension is greater than or equal to 0.

5. A process according to any one of the preceding claims, further comprising, after the step of contacting the aluminum source with the aqueous solution comprising a base and with the aqueous solution comprising a chlorine salt, a filtration step. A method according to any one of the preceding claims, further comprising a washing step. A process according to any one of claims 1 to 4 and 6 to 11, further comprising, after the step of bringing the aluminum source into contact with the aqueous solution comprising a base and with the aqueous solution, and after optional acidification and / or filtration and / or washing, a shaping step into the form of an object, comprising shaping a charge. A method according to any one of the preceding claims, wherein the charge does not comprise a binder, in particular no organic binder, and does not comprise an acid. Product comprising a lithiated bayerite obtained by the process according to any one of the preceding claims, said product comprising, and preferably being essentially composed of: - water, and - crystallites, at least a part, preferably all, of said crystallites being composed of lithiated bayerite, the average size of the lithiated bayerite crystallites being greater than or equal to 2 nm and less than or equal to 25 nm, and said product having a cumulative content of aluminium hydroxide and boehmite less than or equal to 10%, said product comprising at least the elements Li, Cl, Al, O and H, the elements Li, Cl and Al being present in said dry product in the following contents, determined by inductively coupled plasma spectrometry, in weight percentages: - 2% < Li < 5%, - 10% < Cl < 26%, - 15% < Al < 30%. Product according to the preceding claim, wherein the lithiated bayerite crystallites have an average size between 2 and less than 10 nm. Product according to one of claims 14 or 15, which is in the form of objects having dimensions of at least 0.2 mm and which is essentially made up of water and crystallites. Product according to any one of claims 14 to 16, which does not include an organic binder. Lithium capture device, in particular extraction column, comprising a product according to any one of claims 14 to 17.

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