Method and device for lithium adsorption extraction in a simulated moving bed consisting of three zones

Abstract

A simulated moving-bed lithium adsorption process and apparatus in which a column (Ci) comprising a solid adsorbent is fed with a feed (F) comprising lithium and a desorbent (D) and is withdrawn of a raffinate (R) and an extract (E2), the column being divided into several predetermined quantities of solid adsorbent according to a permutation period defining the following zones: a zone I between the injection of the desorbent and the withdrawal of an eluate (E1) and the extract, a zone II between the withdrawal of the raffinate and the injection of the desorbent, and a zone III between the injection of the feed and the withdrawal of the raffinate, in which each permutation period comprises two steps: a step A of eluate withdrawal from zone I and a step B of extract withdrawal from zone I. Figure 3 to be published

Description

Title of the invention: Method and device for lithium adsorption extraction in a simulated moving bed consisting of three zones technical field

[0001] The present invention relates to the field of lithium separation by adsorption phenomena. The present invention also relates to the field of simulated moving bed separation. Previous technique

[0002] Demand for lithium has increased sharply in recent years, largely due to the rise of electric mobility. To meet this demand, improving existing lithium extraction processes is essential. Lithium can be extracted from rocks or from brines. In the case of brines, traditional processes are based on open-air evaporation, a slow and low-yield process. Adsorption processes have recently been developed and offer promising prospects.

[0003] French patent FR3053264B1 describes the preparation of a lithium-selective adsorbent of the formula (LiCl)x.2Al(OH)3,nH2O, where n is between 0.01 and 10 and x is between 0.4 and 1, for the extraction of lithium from saline solutions. This type of adsorbent can be used in cyclic adsorption and elution processes in which the brine passes through at least one column on which the lithium is captured. This column is then fed with a desorbent (eluent) to desorb the desired lithium.

[0004] Patent application FR3131225A1 describes a simulated moving bed lithium adsorption extraction process. Summary of the invention

[0005] In the context described above, a first object of the present description is to overcome the problems of the prior art and to provide a process and a device for lithium adsorption extraction that limits the consumption of desorbent in the process in order to limit in particular its environmental impact.

[0006] A second objective of this description is to increase the lithium concentration in the extract. The high lithium concentration in the extract makes it possible, in particular, to reduce the amount of water to be evaporated or separated later in the process, thus simplifying the equipment of the extraction device and resulting in significant energy savings.

[0007] A third object of the present description is obtaining a very low content of impurities such as calcium, magnesium or boron in the extract, which allows to limit or even eliminate the need for lithium purification steps downstream of adsorption extraction.

[0008] Advantageously, the applicant has identified that processes and devices for lithium adsorption extraction in a simulated moving bed consisting of three zones could be implemented to increase the lithium concentration in the extract, particularly when each period between 2 valve permutations is divided into two stages (or sub-periods).

[0009] According to a first aspect, the aforementioned objects, as well as other advantages, are obtained by a simulated moving bed lithium adsorption extraction process comprising the following step: - at least one column is fed with at least one feed comprising lithium and a desorbent, and at least one raffinate (depleted in lithium relative to the feed) and at least one extract (enriched in lithium relative to the feed) are withdrawn from the column, the at least one column comprising an adsorbent solid, the feeding and withdrawal points of the at least one column being shifted over time by a value corresponding to a predetermined quantity of adsorbent solid with a permutation period and determining a plurality of column operating zones, and in particular the following main zones designated by definition by a number: - a lithium desorption zone I located between the point of injection of the desorbent and a point of withdrawal of an eluate and the extract; - a zone II comprising the point where the raffinate is withdrawn and the point where the desorbent is injected; and - a lithium adsorption zone III located between the charge injection point and a raffinate withdrawal point, in which each permutation period comprises two stages: - a first step A during which the eluate is drawn from zone I; and - a second step B during which the extract is drawn from zone I.

[0010] According to one or more embodiments, the eluate is recycled at least partially in zone III.

[0011] According to one or more embodiments, the eluate is recycled at least partially at the point of injection of the charge.

[0012] According to one or more embodiments, the recycling rate is between 2 and 12, preferably between 3 and 9, most preferably between 5 and 8. According to one or more embodiments, the recycling includes, and preferably consists of, all or part of the eluate Eb

[0013] According to one or more embodiments, the ratio of the volumetric flow rate of the desorbent to the volumetric flow rate of the charge is less than 1, preferably less than 0.6, preferably less than 0.5. According to one or more embodiments, the ratio of the volumetric flow rate of the desorbent to the volumetric flow rate of the charge is between 0.1 and 1.0, preferably between 0.2 and 0.6, very preferably between 0.2 and 0.5.

[0014] According to one or more embodiments, the at least one column comprises a plurality of columns or adsorbers, the feeding and withdrawal points of the columns or adsorbers being shifted over time by a value corresponding to one column or adsorber.

[0015] According to one or more embodiments, the plurality of columns or adsorbers comprises at least 3 columns or adsorbers, preferably at least 4 columns or adsorbers, preferably between 4 and 12 columns or adsorbers, preferably between 5 and 10, preferably between 5 and 7 columns or adsorbers.

[0016] According to one or more embodiments, the adsorbent solid is distributed in zones I to III according to configurations of type a / b / c, in which the distribution of the adsorbent solid, in relation to the total quantity of adsorbent solid, is as follows: - a is the percentage of adsorbent solid in zone I; - b is the percentage of solid adsorbent in zone II; and - c is the percentage of solid adsorbent in zone III, a process in which: - a is between 20% and 70%, preferably between 30% and 50%; - b is between 10% and 30%, preferably between 10% and 20%; and - c is between 20% and 70%, preferably between 30% and 50%.

[0017] According to one or more embodiments, a is substantially equal to 40%, b is substantially equal to 20% and c is substantially equal to 40%.

[0018] According to one or more embodiments, the at least one column comprises a plurality of beds of solid adsorbent separated by trays, the feeding and withdrawal points in the trays of the column being shifted over time by a value corresponding to one bed of adsorbent.

[0019] According to one or more embodiments, the at least one column comprises at least 3 beds of adsorbent solid, preferably at least 4 beds of adsorbent solid, preferably between 4 and 12 beds of adsorbent solid, preferably between 5 and 10 beds of adsorbent solid, preferably between 5 and 7 beds of adsorbent solid.

[0020] According to one or more embodiments, the adsorbent solid comprises and preferably consists of lithium bayerite and / or lithium boehmite.

[0021] According to one or more embodiments, wherein the charge comprises at least 0.05 g / L weight of lithium element, preferably in the form of LiCl, relative to the total weight of the charge.

[0022] According to one or more embodiments, the adsorbent solid comprises between 0.1% by weight and 5% by weight of lithium element, preferably in the form of LiCl, relative to the total weight of the adsorbent solid.

[0023] According to one or more embodiments, the permutation period is between 500 seconds and 10000 seconds, preferably between 1000 seconds and 5000 seconds.

[0024] According to one or more embodiments, step A is carried out for at least 30% and preferably at least 40% of the permutation period.

[0025] According to one or more embodiments, the adsorbent solid comprises between 0.1% by weight and 5% by weight of lithium element, preferably in the form of LiCl, relative to the total weight of the adsorbent solid.

[0026] According to one or more embodiments, the adsorbent solid comprises at least one lithium aluminum oxyhydroxide Al10(OH) and / or at least one lithium aluminum hydroxide Al(OH)3.

[0027] According to one or more embodiments, the adsorbent solid comprises and preferably consists of a solid material of formula (LiCl)x.2Al(OH)3,nH2O, in which n is between 0.01 and 10, and x is between 0.4 and 1.

[0028] According to one or more embodiments, the desorbent is chosen from the group consisting of water, lithium water, brine, preferably water.

[0029] According to one or more embodiments, the desorbent comprises between 0 g / L and 1 g / L of lithium element, preferably in the form of LiCl, relative to the total weight of the desorbent.

[0030] According to one or more embodiments, the steps of the process are carried out at a temperature (e.g. temperature in the adsorbent solid) between 0°C and 160°C and preferably between 15°C and 80°C, in particular to promote accelerated perforation of the adsorbent solid.

[0031] According to one or more embodiments, the steps of the process are carried out at a controlled pressure (e.g., pressure in the adsorbent solid) such that the liquid phase remains constant throughout the process according to the invention. According to one or more embodiments, the pressure in the beds of adsorbent solid is between 0.09 MPa and 5 MPa, preferably between 0.095 MPa and 3.5 MPa, preferably between 0.1 MPa and 2.5 MPa.

[0032] According to a second aspect, the aforementioned objects, as well as other advantages, are obtained by a simulated moving bed lithium adsorption extraction device comprising the following elements: - at least one column adapted to be fed with at least one charge comprising lithium and a desorbent, and to be withdrawn from the column at least one raffinate and at least one extract, and at least one column comprising a solid adsorbent, the feed and withdrawal points of at least one column being adapted to be shifted over time by a value corresponding to a predetermined quantity of adsorbent solid with a permutation period and determining a plurality of column operating zones, and in particular the following main zones designated by definition by a number: - a lithium desorption zone I located between the point of injection of the desorbent and a point of withdrawal of an eluate and the extract; - a zone II comprising the point where the raffinate is withdrawn and the point where the desorbent is injected; and - a lithium adsorption zone III located between the charge injection point and a raffinate withdrawal point, the device comprising a first eluate outlet conduit connected to zone I, and a second extract outlet conduit connected to zone I.

[0033] Other features and advantages of the invention according to the aforementioned aspects will become apparent from the following description and non-limiting examples of embodiments, with reference to the figures attached and described below. List of figures

[0034] Fig. 1 represents a simulated moving bed lithium adsorption extraction process according to the invention, using a plurality of columns.

[0035] Fig. 2 represents a simulated moving bed lithium adsorption extraction process according to the invention, using a single column comprising a plurality of beds of solid adsorbent separated by trays.

[0036] Fig. 3 shows a simulated moving bed lithium adsorption extraction process according to the invention featuring a first two-stage permutation period.

[0037] Fig. 4 shows the process according to Fig. 3 presenting a second two-step permutation period.

[0038] Figure 5 shows a simulated moving bed lithium adsorption extraction process according to the invention with eluate recycling. Description of the implementation methods

[0039] Embodiments of the device and method according to the aforementioned aspects will now be described in detail. In the following detailed description, numerous specific details are presented to provide a more thorough understanding of the device and method. However, it will be apparent to those skilled in the art that the device and method can be implemented without these specific details. In other cases, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0040] In this application, the term "include" is synonymous with (means the same as) "include" and "contain," and is inclusive or open-ended and does not exclude other unstated elements. It is understood that the term "include" includes the exclusive and closed term "consist." Furthermore, in this description, the terms "essentially" or "substantially" correspond to an approximation of ±20%, preferably ±10%, most preferably ±5%.

[0041] The present invention relates to a lithium adsorption extraction process employing a simulated countercurrent chromatography or simulated moving bed separation process, which we will hereafter collectively refer to as the "LMS" process. The lithium adsorption extraction process by simulated countercurrent chromatography or simulated moving bed according to the invention can employ synchronous movement of the inlet / outlet lines, but can also employ asynchronous movement of the inlet / outlet valves in a multicolumn system, the latter case also being known as VARICOL. In particular, the sequencing of injection and collection points takes place over one operating cycle of the device. Hereafter, the cycle time refers to the time it takes for the injection and collection points to be sequenced until they return to their initial position in the device.At the end of a cycle, the device returns to its initial configuration. According to one or more embodiments, a cycle comprises as many periods as there are columns or beds of adsorbent solid. For example, a cycle of an "LMS" process according to the invention comprising 8 columns or 8 beds of adsorbent solid is produced in 8 periods.

[0042] According to the invention, the LMS method and device uses / includes at least one column (or adsorbers), the column(s) being arranged in series and implementing a flow of fluids in a medium of solid particles, called the adsorbent solid or granular medium, in a flow direction of the fluid(s) implemented in the column(s). The fluid successively passing through the n column(s) C, i being between 1 and n, is called the main fluid to distinguish it from other secondary fluids that can be added to the main fluid via a distribution and collection device (e.g., valve systems external to the column(s)), generally located at the column inlet or outlet, for example, between two successive columns. According to one or more embodiments, at least one column Ci is interconnected in a closed loop, i.e.that the main fluid passes successively through columns Ci to Cn and is recycled from column Cn to column Cp.

[0043] With reference to [Fig. 1], according to one or more embodiments, the method and device according to the invention uses / comprising a plurality n of columns (in this For example, from column C1 to column C5), each column comprising dispensing devices (for the charge F and the desorbent D) and collection devices (for the raffinate R, the eluent E1, and the extract E2). In one or more embodiments, n is greater than or equal to 3. In one or more embodiments, n is greater than or equal to 4. In one or more embodiments, n is between 4 and 12, preferably between 5 and 10, most preferably between 5 and 7.

[0044] With reference to [Fig. 2], the LMS process and device uses / includes a column Ci implementing the flow of fluids through a plurality of beds of adsorbent solid Ai arranged in series according to a flow direction of the fluid(s) implemented in the column. The fluid successively passing through the beds of adsorbent solid Ai is called the main fluid to distinguish it from secondary fluids that can be added to the main fluid via a distribution and collection device, also called a tray P, generally located between two successive beds of adsorbent solid Ai.

[0045] A tray P comprises at least one collection zone and a valve system for collecting the main fluid and / or injecting secondary fluids and mixing these secondary fluids with the main fluid. A tray also comprises at least one distribution zone for distributing the fluid resulting from the mixing of the main fluid and the secondary fluids onto the granular bed located immediately downstream, in the direction of the main fluid flow.

[0046] With reference to [Fig. 2], a column is divided into a plurality of trays P and adsorbent beds A, the tray P being located directly upstream of the adsorbent bed A, in the direction of the main fluid flow. Furthermore, the term adsorbent bed Ai+i designates the next adsorbent bed located downstream of the adsorbent bed A, in the direction of the main fluid flow. Similarly, a tray Pi+i designates the next tray located downstream of the tray P, in the direction of the main fluid flow. According to one or more embodiments, the adsorbent beds A are interconnected in a closed loop, i.e., the main fluid is recycled from the adsorbent bed An to the adsorbent bed Ab.

[0047] According to one or more embodiments, the method and device according to the invention uses / comprising at least one separation column Ci divided into n beds of adsorbent solid A; separated by n trays (defining interbed zones), each tray being itself divisible into several sectors or regions, called panels. According to one or more embodiments, n is greater than or equal to 3. According to one or more embodiments, n is greater than or equal to 4. According to one or more embodiments, n is between 4 and 12, preferably between 5 and 10, most preferably between 5 and 7.

[0048] In the following text, the term "step" refers to an operation or group of similar operations performed on a given flow at a certain point in the process. The process is described in its various steps, taken in the order in which the flows or products occur.

[0049] The simulated moving bed lithium adsorption extraction process according to the invention comprises the following step: - one or more column(s) C are fed with at least one charge F comprising lithium and a desorbant D, and at least one raffinate R, at least one eluate Ei and at least one extract E2 are withdrawn from at least one column Ci, the column(s) Ci comprising a solid adsorbent.

[0050] With reference to [Fig.1], according to one or more embodiments, the solid adsorbent is distributed in a plurality of columns C; (eg adsorbers).

[0051] With reference to [Fig.2], according to one or more embodiments, the adsorbent solid is distributed in beds of adsorbent solid A; of at least one column Ci, the beds of adsorbent solid A, being separated by trays P;.

[0052] With reference to [Fig.3], the method according to the invention proposes to implement a simulated counter-current consisting of three zones: - zone III between the charge injection F and the raffinate withdrawal R; - zone II, located between the withdrawal of raffinate R and the injection of desorbent (or eluent) D; and - Zone I, located between the injection of the desorbent and the withdrawal of eluate Ei or extract E2. In this example, the device comprises 5 columns, and during the first ST permutation period, the load F is injected at the inlet of column C1, the raffinate is withdrawn at the outlet of column C2, the desorbent D is injected at the inlet of column C3, and the eluate Ei and extract E2 are withdrawn at the outlet of column C5. Referring to [Fig. 4], after one ST permutation period, the load F is injected at the inlet of column C2, the raffinate is withdrawn at the outlet of column C3, the desorbent D is injected at the inlet of column C4, and the eluate Ei and extract E2 are withdrawn at the outlet of column C1.

[0053] Furthermore, according to the invention, each period (defined as the time period between two permutations of the injection and withdrawal valves) is divided into two stages (or sub-periods): - a step A during which a flow of eluate Ei is withdrawn from (end of) zone I; and - a step B during which the lithium-rich extract E2 (relative to charge F) is withdrawn from (end of) zone I.

[0054] Thus, according to the invention, the supply and withdrawal points of the column(s) Ci are shifted over time (for example by a corresponding value to a column (e.g., an adsorbent) or an adsorbent bed of a column) with a permutation period and determining a plurality of operating zones of the column(s) Q, and in particular the following main zones designated by definition by a number: - a lithium desorption zone I located between the injection point of the desorbent D and a withdrawal point of an eluate Ei and of the extract E2; - a zone II comprising the point of withdrawal of the raffinate R and the point of injection of the desorbent D; and - a lithium adsorption zone III located between the injection point of charge F and a withdrawal point of raffinate R, in which each permutation period comprises two stages: - a first step A during which the eluate is drawn from zone I; and - a second step B during which the extract is drawn from zone I.

[0055] Advantageously, the process according to the invention makes it possible to limit the consumption of desorbent in the process in order to limit, in particular, its environmental impact. Furthermore, the process according to the invention makes it possible to increase the concentration of lithium in the E2 extract.

[0056] Furthermore, the process according to the invention makes it possible to obtain an E2 extract with a particularly low impurity content. Indeed, the process according to the invention allows for increased separation of lithium from alkali metals, preferably sodium (Na) and potassium (K), and from alkaline earth metals, preferably magnesium (Mg), calcium (Ca), and strontium (Sr), which are present in significant quantities in the saline solutions treated in said extraction process. The process according to the invention also allows for the selective separation of lithium from other compounds such as boron and sulfates.

[0057] According to one or more embodiments, the raffinate R is removed from the process according to the invention. The raffinate can, for example, be sent to a natural reservoir (sea, salt flat, etc.).

[0058] According to one or more embodiments, the eluate Ei is removed from the process according to the invention, the eluate Ei can for example be sent into a natural reservoir (sea, salt flat, etc...).

[0059] With reference to [Fig.5], according to one or more embodiments, the eluate Ei is recycled, at least partially, in zone III, preferably at the point of injection of the charge F.

[0060] With reference to [Fig.3], according to one or more embodiments, the feed and withdrawal points of the columns C; are shifted over time by a value corresponding to a column Ci (e.g. an adsorber).

[0061] With reference to [Fig.2], according to one or more embodiments, the feed and withdrawal points of at least one column C; are shifted over time by a value corresponding to an adsorbent bed A;.

[0062] According to one or more embodiments, the adsorbent solid is distributed in zones I to III according to so-called a / b / c type configurations, i.e. the distribution of the adsorbent solid, in relation to the total quantity of adsorbent solid, is as follows: - a is the percentage (e.g., weight or volume) of adsorbent solid in zone I; - b is the percentage (e.g., weight or volume) of adsorbent solid in zone II; and - c is the percentage (e.g., weight or volume) of adsorbent solid in zone III, a process in which: - a is between 20% and 70%, preferably between 30% and 50%; - b is between 10% and 30%, preferably between 10% and 20%; and - c is between 20% and 70%, preferably between 30% and 50%.

[0063] According to one or more embodiments, a is substantially equal to 40%, b is substantially equal to 20% and c is substantially equal to 40%.

[0064] According to one or more embodiments, the temperature is set so that the temperature in the adsorbent solid remains between 0°C and 160°C and preferably between 15°C and 80°C.

[0065] According to one or more embodiments, the pressure is adjusted so that the liquid phase remains constant throughout the process according to the invention. According to one or more embodiments, the pressure in the adsorbent solid is between 0.09 MPa and 5 MPa, preferably between 0.095 MPa and 3.5 MPa, preferably between 0.1 MPa and 2.5 MPa.

[0066] According to one or more embodiments, the main fluid passes through the columns C; and / or the beds of adsorbing solid A; in the downward direction.

[0067] According to one or more embodiments, the cycle duration is at least 20 minutes, preferably at least 40 minutes, such as being between 1 and 10 hours. Preferably, the cycle duration used is between 2 and 8 hours. The cycle duration corresponds to the permutation period ST (period between two successive permutations of feeds / extractions) multiplied by the total number of injection / withdrawal points, such as the total number of columns Ci used (see example in [Fig. 1]) or of beds of adsorbent solid A used (see example in [Fig. 2]).

[0068] According to one or more embodiments, the permutation period ST is between 500 seconds and 10000 seconds, preferably between 1000 seconds and 5000 seconds.

[0069] According to one or more embodiments, step A is performed for at least 30%, and preferably at least 40%, of the permutation period ST. According to one or more embodiments, step A is performed for between 30% and 60%, preferably between 40% and 50%, of the permutation period ST. According to one or more embodiments, step A is performed for less than 50% of the permutation period ST. According to one or more embodiments, during a permutation period ST, step A is performed for between 150 seconds and 5000 seconds, preferably between 300 seconds and 2500 seconds. According to one or more embodiments, step B is performed for between 30% and 70%, preferably between 40% and 60%, of the permutation period ST. According to one or more embodiments, during a permutation period ST, step B is carried out for 150 seconds and 5000 seconds, preferably between 300 seconds and 2500 seconds.

[0070] According to one or more embodiments, the recycling rate (i.e., ratio of the average recycling flow rate (average of zone flow rates weighted by the number of columns or beds of adsorbent solid per zone) to the loading flow rate) is between 2 and 12, preferably between 3 and 9, most preferably between 5 and 8. According to one or more embodiments, the recycling includes, and preferably consists of, all or part of the eluate Ei (obtained during step A).

[0071] According to one or more embodiments, the volumetric flow rate ratio of the desorbent to the volumetric flow rate of the charge is less than 1, preferably less than 0.6, preferably less than 0.5. According to one or more embodiments, the volumetric flow rate ratio of the desorbent to the volumetric flow rate of the charge is between 0.1 and 1.0, preferably between 0.2 and 0.6, most preferably between 0.2 and 0.5.

[0072] According to one or more embodiments, the supply and withdrawal points of T at least one column (Ci) are offset synchronously.

[0073] According to one or more embodiments, the feed and withdrawal points of at least one column (Ci) are shifted asynchronously. In this case, the cycle time refers to the time it takes for the injection and collection points to be sequenced until they return to their initial position in the device. The amount of adsorbent solid contained in each of zones I, II, and III, as defined above, is then calculated as the average amount of adsorbent solid contained in each zone over the cycle time. Similarly, the number of beds in each of zones I, II, and III, as defined above, is calculated as the average number of adsorbent beds contained in each zone over the cycle time, this value being non-integer.

[0074] According to one or more embodiments, the charge comprises and preferably consists of a (saline) solution containing lithium and which may or may not be saturated with salts, such as a brine.

[0075] According to one or more embodiments, the charge comprises at least one of the following elements: Na, K, Rb, Cs, Mg, Ca, Sr, Ba, F, Cl, Br, I, SO4, CO3, NO3, B and HCO3.

[0076] Said charge may be any natural saline solution, concentrated or obtained from a lithium extraction or processing method. For example, said saline solution used in the extraction method according to the invention may advantageously be chosen from brines from salt lakes or geothermal springs, brines subjected to evaporation to obtain concentrated lithium brines, seawater, effluents from lithium chloride or lithium hydroxide production plants and effluents from lithium extraction processes from minerals.

[0077] According to one or more embodiments, the charge comprises at least 0.05 g / L of lithium element, preferably at least 0.1 g / L, preferably in the form of LiCl, relative to the total weight of the charge. According to one or more embodiments, the charge comprises between 0.5 g / L and 1 g / L of lithium element, preferably in the form of LiCl, relative to the total weight of the charge.

[0078] According to one or more embodiments, the desorbent is selected from the group consisting of water, lithium water, or brine, preferably lithium brine. According to one or more embodiments, the desorbent comprises between 0 g / L and 1 g / L of lithium element, preferably in the form of LiCl, relative to the total weight of the desorbent. According to one or more embodiments, the desorbent comprises less than 0.005 g / L of lithium element, preferably less than 0.01 g / L of lithium element, relative to the total weight of the desorbent.

[0079] According to one or more embodiments, the adsorbent comprises at least one lithiaated aluminium oxyhydroxide AIO(OH) and / or at least one lithiaated aluminium hydroxide A1(OH)3.

[0080] According to one or more embodiments, the at least one lithiased aluminum oxyhydroxide Al₂O₃(OH) comprises lithiased boehmite. According to one or more embodiments, the at least one lithiased aluminum oxyhydroxide Al₂O₃(OH) comprises at least 60% by weight, preferably at least 80% by weight, of lithiased boehmite, relative to the total weight of the at least one lithiased aluminum oxyhydroxide Al₂O₃(OH). According to one or more embodiments, the at least one lithiased aluminum oxyhydroxide Al₂O₃(OH) consists of lithiased boehmite.

[0081] According to one or more embodiments, the at least one lithia-treated aluminum hydroxide A1(OH)3 comprises lithia-treated bayerite. According to one or more embodiments of In this embodiment, the at least one lithiased aluminum hydroxide A1(OH)3 comprises at least 60% by weight, preferably at least 80% by weight, of lithiased bayerite, relative to the total weight of the at least one lithiased aluminum hydroxide A1(OH)3. According to one or more embodiments, the at least one lithiased aluminum hydroxide A1(OH)3 consists of lithiased bayerite.

[0082] According to one or more embodiments, the adsorbent solid comprises at least 0.1% by weight of lithium (preferably in the form of LiCl), preferably at least 1% by weight, and most preferably at least 1.5% by weight, relative to the total weight of the adsorbent solid. According to one or more embodiments, the adsorbent solid comprises between 0.1% by weight and 5% by weight of lithium (preferably in the form of LiCl), preferably between 1% by weight and 4% by weight, and most preferably between 1.5% by weight and 3% by weight, relative to the total weight of the adsorbent solid.

[0083] According to one or more embodiments, the adsorbent solid comprises and preferably consists of a solid material of formula (LiCl) x .2Al(OH) 3 ,nH 2 O, in which n is between 0.01 and 10, and x is between 0.4 and 1. According to one or more embodiments, n is between 0.1 and 5, preferably between 0.1 and 1, most preferably between 0.1 and 0.5.

[0084] According to one or more embodiments, the adsorbent solid has a specific surface area characterized by nitrogen adsorption according to the BET method of between 1 m2 / g and 30 m2 / g, preferably between 1 m2 / g and 20 m2 / g.

[0085] According to one or more embodiments, the adsorbent solid is in the form of beads or extrudates of cylindrical, hollow cylinder, wheel-shaped, trilobed or multilobed, or any other geometric shape understood by those skilled in the art. According to one or more embodiments, the adsorbent solid is in the form of beads with an average diameter of between 0.1 mm and 1.5 mm, preferably between 0.1 mm and 1 mm, and more preferably between 0.1 mm and 0.3 mm. According to one or more embodiments, the adsorbent solid is in the form of extrudates with a diameter of between 0.15 mm and 5 mm, preferably between 0.2 mm and 3 mm, and more preferably between 0.25 mm and 1.8 mm.

[0086] The solid adsorbent material is characterized using the following techniques: nitrogen adsorption for determining the specific surface area according to the BET method (e.g., ASTM D 3663-7); and X-ray fluorescence for elemental analysis. The average diameter of the extrudates is measured by optical measurement of at least 10 extrudates, preferably at least 50 extrudates. For example, when the solid adsorbent is in the form of beads, the number-average diameter of the adsorbent solid is estimated using a particle size distribution analysis of a sample. of at least 50 adsorbent beads by imaging according to ISO 13322-2:2006 using a conveyor belt that allows the sample to pass in front of the camera lens. The number-average diameter is then calculated from the particle size distribution by applying ISO 9276-2:2001. Examples

[0087] The process according to the invention is applied for the purification and separation of a lithium brine comprising: - 0.4 g / L of lithium element; - 110 g / L as chlorine; - 70 g / L as elemental sodium.

[0088] The adsorbent considered for the separation is a lithia-coated bayerite.

[0089] The process temperature is 20°C.

[0090] The desorbent is water containing 0.15 g / L of lithium element.

[0091] The simulated moving bed lithium adsorption extraction device comprises 5 C1-C5 columns, each comprising an adsorbent bed 1m long and 1.25cm in inner radius.

[0092] The cycle used is the one with recycling of the eluate Ei at the inlet in zone III during step A, as shown in [Fig.5].

[0093] The distribution of beds by zone is as follows: - 2 beds in zone I (i.e. 40% of the solid adsorbent); - 1 bed in zone II (i.e., 20% of the adsorbent solid); and - 2 beds in zone III (i.e. 40% of the solid adsorbent).

[0094] The beds are traversed in downward mode for the adsorption and elution phases.

[0095] Step A lasts 1300 seconds. Step B lasts 1400 seconds.

[0096] The loading flow rate F is 32.2 cm³ / min during step A and 58 cm³ / min during step B. The desorbent flow rate D is 20 cm³ / min. The raffinate flow rate R is 52.2 cm³ / min. The eluate flow rates E1 and extract flow rates E2 are 25.8 cm³ / min.

[0097] The eluate Ei is directly injected with the charge F at the beginning of zone III during step A.

[0098] The lithium concentration of the extract is 1.61 g / L.

[0099] The lithium yield is 87.5%.

Claims

Demands

1. A simulated moving bed lithium adsorption extraction process comprising the following step: - at least one column (Ci) is fed with at least one charge (F) comprising lithium and a desorbent (D), and at least one raffinate (R) and at least one extract (E2) are withdrawn from the column (Ci), the at least one column (Ci) comprising an adsorbent solid, the feeding and withdrawal points of the at least one column (Ci) being shifted over time by a value corresponding to a predetermined quantity of adsorbent solid with a permutation period and determining a plurality of operating zones of the column (Ci), and in particular the following main zones designated by definition by a number: - a lithium desorption zone I comprising the desorbent injection point (D) and a withdrawal point of an eluate (EJ) and the extract (E2);- a zone II comprising between the raffinate withdrawal point (R) and the desorbent injection point (D); and - a lithium adsorption zone III comprising between the charge injection point (F) and a raffinate withdrawal point (R), in which each permutation period comprises two steps: - a first step A during which the eluate (Ei) is withdrawn from zone I; and - a second step B during which the extract (E2) is withdrawn from zone I.

2. A process according to claim 1, wherein the eluate (Ei) is recycled at least partially into zone III.

3. A method according to claim 1 or claim 2, wherein the eluate (EJ) is recycled at least partially at the point of injection of the charge (F).

4. A method according to any one of the preceding claims, wherein at least one column (Ci) comprises a plurality of columns or adsorbers, the feed and withdrawal points of the columns or adsorbers being shifted over time by a value corresponding to one column or adsorber.

5. A method according to claim 3, wherein the plurality of columns or adsorbers comprises at least 3 columns or adsorbers, preferably at least 4 columns or adsorbers, preferably between 4 and 12 columns or adsorbers, preferably between 5 and 10, preferably between 5 and 7 columns or adsorbers.

6. A method according to any one of the preceding claims, wherein the adsorbent solid is distributed in zones I to III according to configurations of type a / b / c, wherein the distribution of the adsorbent solid, relative to the total amount of adsorbent solid, is as follows: - a is the percentage of adsorbent solid in zone I; - b is the percentage of adsorbent solid in zone II; and - c is the percentage of adsorbent solid in zone III, a method wherein: - a is between 20% and 70%, preferably between 30% and 50%; - b is between 10% and 30%, preferably between 10% and 20%; and - c is between 20% and 70%, preferably between 30% and 50%.

7. A method according to claim 6, wherein a is substantially equal to 40%, b is substantially equal to 20% and c is substantially equal to 40%.

8. A method according to any one of the preceding claims, wherein the at least one column (Ci) comprises a plurality of beds of solid adsorbent separated by trays, the feeding and withdrawal points in the trays of the column (Ci) being offset over time by a value corresponding to one bed of adsorbent.

9. A method according to claim 8, wherein at least one column (Ci) comprises at least 3 beds of adsorbent solid, preferably at least 4 beds of adsorbent solid, preferably between 4 and 12 beds of adsorbent solid, preferably between 5 and 10 beds of adsorbent solid, preferably between 5 and 7 beds of adsorbent solid.

10. A method according to any one of the preceding claims, wherein the adsorbent solid comprises and preferably consists of lithium bayerite and / or lithium boehmite.

11. A method according to any one of the preceding claims, wherein the charge (F) comprises at least 0.05 g / L weight of lithium element, preferably in the form of LiCl, relative to the total weight of the charge (F).

12. A method according to any one of the preceding claims, wherein the adsorbent solid comprises between 0.1 wt% and 5 wt% of lithium element, preferably in the form of LiCl, relative to the total weight of the adsorbent solid.

13. A method according to any one of the preceding claims, wherein the permutation period is between 500 seconds and 10000 seconds, preferably between 1000 seconds and 5000 seconds.

14. A method according to any one of the preceding claims, wherein step A is carried out for at least 30% and preferably at least 40% of the permutation period.

15. Simulated moving bed lithium adsorption extraction device comprising the following elements: - at least one column (Ci) adapted to be fed with at least one charge (F) comprising lithium and a desorbant (D), and to be withdrawn from at least one raffinate (R) and at least one extract (E2) and from the column (Ci), the at least one column (Ci) comprising an adsorbent solid, the feeding and withdrawal points of the at least one column (Ci) being adapted to be offset over time by a value corresponding to a predetermined quantity of adsorbent solid with a permutation period and determining a plurality of operating zones of the column (Ci), and in particular the following principal zones designated by definition by a number: - a lithium desorption zone I comprising the desorbant injection point (D) and a withdrawal point of an eluate (EJ) and the extract (E2);- a zone II comprising between the raffinate withdrawal point (R) and the desorbent injection point (D); and - a lithium adsorption zone III comprising between the charge injection point (F) and a raffinate withdrawal point (R), the device comprising a first eluate outlet conduit (Ei) connected to zone I, and a second extract outlet conduit (E2) connected to zone I.;

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