METHOD AND DEVICE FOR SIMULATED MOVING BED EXTRACTION BY LITHIUM ADSORPTION

Description

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. Prior art

[0002] Lithium ions coexist with massive amounts of metals such as alkalis, alkaline earths, boron, and sulfates, especially in saline solutions such as brines. Thus, they must be economically and selectively extracted from these saline solutions. Indeed, the chemical properties of lithium and alkali metals, preferably sodium (Na), and potassium (K), and alkaline earths, preferably magnesium (Mg), calcium (Ca), and strontium (Sr), make the separation of these elements difficult.

[0003] Solid materials based on aluminum oxyhydroxide AIO(OH) and / or aluminum hydroxide Al(OH) 3 are known for their use as adsorbents in the phenomena of adsorption / desorption of lithium ions and in particular in processes for the extraction by adsorption of lithium from saline solutions. Advantageously, said materials allow the intercalation of lithium atoms in their structure and thus the extraction of lithium from a charge by adsorption, and the production of a lithium-enriched extract by desorption using a desorbent.

[0004] Patent application FR 3053264 A1 describes in particular a process for the extraction by adsorption of lithium from saline solutions, said process using a solid material of formula (LiCl) x .2Al(OH) 3 ,nH2O with n being between 0.01 and 10, x being between 0.4 and 1, for the extraction of lithium from saline solutions.

[0005] Although the use of such materials allows acceptable levels of lithium purification to be achieved, lithium production by adsorption phenomena can be improved. Summary of the invention

[0006] 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 method and a device for lithium adsorption extraction making it possible to increase the concentration of lithium in the extract. The high concentration of lithium in the extract makes it possible in particular to reduce the quantity of water to be evaporated or separated in the rest of the process, thus allowing a simplification of the equipment of the extraction device and significant energy savings.

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

[0008] A third object of this description is to limit the consumption of desorbent in the process in order to limit its environmental impact.

[0009] Advantageously, the applicant has identified that solid lithiated materials based on aluminum oxyhydroxide AIO(OH) and / or aluminum hydroxide Al(OH) 3 were suitable for the adsorption extraction of lithium in a simulated moving bed or simulated countercurrent separation process and device.

[0010] According to a first aspect, the aforementioned objects, as well as other advantages, are obtained by a process for extraction by adsorption of lithium in a simulated moving bed comprising the following step: at least one column is fed with at least one feed comprising lithium and a desorbent, and at least one extract and at least one raffinate are withdrawn from the column, the at least one column comprising an adsorbent solid comprising at least one lithiated aluminum oxyhydroxide AIO(OH) and / or at least one lithiated aluminum hydroxide Al(OH) 3, the at least one column being interconnected in a closed loop, the feed and withdrawal points of the at least one column being 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, and in particular the following main zones designated by definition by a number: a lithium desorption zone I between a desorbent injection point and an extract withdrawal point;a zone II for desorption of alkali metals other than lithium and / or alkaline earth metals between the point of withdrawal of the extract and a point of injection of the charge comprising lithium; a zone III for adsorption of lithium between the point of injection of the charge and a point of withdrawal of the raffinate; and a zone IV is between the point of withdrawal of the raffinate and the point of injection of the desorbent. ;

[0011] According to one or more embodiments, the at least one column comprises a plurality of columns or adsorbers interconnected in a closed loop, the feed and withdrawal points of the columns or adsorbers being offset over time by a value corresponding to a column or adsorber.

[0012] According to one or more embodiments, the plurality of columns or adsorbers comprises at least 4 columns or adsorbers, preferably between 4 and 24 columns or adsorbers, preferably between 8 and 21 columns or adsorbers, for example between 12 and 15 columns or adsorbers.

[0013] According to one or more embodiments, the adsorbent solid is distributed in zones I to IV according to configurations known as type a / b / c / d, that is to say that the distribution of the adsorbent solid, relative to the total quantity of adsorbent solid, is as follows: a is the quantity of adsorbent solid in zone I; b is the quantity of adsorbent solid in zone II; c is the quantity of adsorbent solid in zone III; and d is the quantity of adsorbent solid in zone IV, process in which: a = 43 % ± 9 % ; b = 29 % ± 6 % ; c = 14 % ± 3 % ; And d = 14 % ± 3 % .

[0014] According to one or more embodiments, the at least one column comprises a plurality of beds of adsorbent solid interconnected in a closed loop and separated by trays, the feed and withdrawal points in the trays of the column being offset over time by an amount corresponding to an adsorbent bed.

[0015] According to one or more embodiments, the at least one column comprises at least 4 beds of adsorbent solid, preferably between 4 and 24 beds of adsorbent solid, preferably between 8 and 21 beds of adsorbent solid, for example between 12 and 15 beds of adsorbent solid.

[0016] According to one or more embodiments, the adsorbent solid beds are distributed in zones I to IV according to configurations known as type a / b / c / d, that is to say that the distribution of the adsorbent solid beds is as follows: a is the number of beds in zone I; b is the number of beds in zone II; c is the number of beds in zone III; and d is the number of beds in zone IV, process in which: a = t * 0 , 43 * 1 ± 0 , 20 ; b = t * 0 , 29 * 1 ± 0 , 20 ; c = t * 0 , 14 * 1 ± 0 , 20 ; And d = t * 0 , 14 * 1 ± 0 , 20 , process in which (the number of beds) t is a natural whole number between 4 and 24, preferably between 8 and 21, for example between 12 and 15 beds of adsorbent solid.

[0017] According to one or more embodiments, a portion of the extract or a stream obtained by concentration and / or purification of said extract is fed into zone II, preferably into a central portion of zone II, very preferably substantially in the middle of zone II, in particular in order to improve the concentration of the extract.

[0018] According to one or more embodiments, the adsorbent solid comprises and preferably consists of lithiated bayerite and / or lithiated boehmite.

[0019] 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.

[0020] 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.

[0021] According to one or more embodiments, the desorbent is chosen from the group consisting of water, lithiated water, brine, preferably water.

[0022] 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.

[0023] According to one or more embodiments, the charge comprises at least 0.1 g / L weight of lithium element, preferably in the form of LiCl, relative to the total weight of the charge.

[0024] According to one or more embodiments, the steps of the method are carried out at a temperature (e.g. temperature in the adsorbent solid) between 0°C and 120°C and preferably between 5°C and 100°C, particularly preferably between 15°C and 80°C, very preferably between 40°C and 80°C, in particular in order to promote accelerated drilling of the adsorbent solid.

[0025] Advantageously, the steps of the process are carried out at a pressure (e.g. pressure in the adsorbent solid) controlled so that the liquid phase remains at all points of 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.

[0026] According to one or more embodiments, the cycle duration is at least 20 min, preferably at least 40 min, such as between 1 hour and 10 hours. Preferably, the cycle duration is between 2 hours and 8 hours.

[0027] According to one or more embodiments, the volume flow rate ratio of the desorbent to the volume flow rate of the feedstock is less than 1, preferably less than 0.5, preferably less than 0.2, very preferably less than 0.1.

[0028] According to one or more embodiments, the volume flow rate ratio of the desorbent to the volume flow rate of the feedstock is between 0.01 and 1.0, preferably between 0.02 and 0.5, very preferably between 0.06 and 0.1.

[0029] According to a second aspect, the aforementioned objects, as well as other advantages, are obtained by a device for extraction by adsorption of lithium in a simulated moving bed comprising the following elements: at least one column adapted to be fed with at least one feed comprising lithium and a desorbent, and to be withdrawn from at least one extract and at least one raffinate from the column, the at least one column comprising an adsorbent solid comprising at least one lithiated aluminum oxyhydroxide AIO(OH) and / or at least one lithiated aluminum hydroxide Al(OH) 3, the at least one column being interconnected in a closed loop, the feed and withdrawal points of the at least one column being 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, and in particular the following main zones designated by definition by a number: a lithium desorption zone I between a desorbent injection point and an extract withdrawal point;a zone II for desorption of alkali metals other than lithium and / or alkaline earth metals between the point of withdrawal of the extract and a point of injection of the charge comprising lithium; a zone III for adsorption of lithium between the point of injection of the charge and a point of withdrawal of the raffinate; and a zone IV is between the point of withdrawal of the raffinate and the point of injection of the desorbent. ;

[0030] Other characteristics and advantages of the invention according to the aforementioned aspects will appear on reading the description below and non-limiting examples of embodiments, with reference to the appended figures described below. List of figures

[0031] There figure 1 represents a process for the extraction by adsorption of lithium in a simulated moving bed according to the invention, using a plurality of columns or adsorbers. The figure 2represents a process for the extraction by adsorption of lithium in a simulated moving bed according to the invention, using a single column comprising a plurality of beds of adsorbent solid separated by trays. The figure 3 shows the concentration profile calculated along a simulated moving bed lithium adsorption extraction column according to the invention. Description of the embodiments

[0032] Embodiments of the device and method according to the foregoing aspects will now be described in detail. In the following detailed description, numerous specific details are set forth in order 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 may be implemented without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0033] In this application, the term "comprise" is synonymous with (means the same as) "include" and "contain", and is inclusive or open and does not exclude other elements not recited. It is understood that the term "comprise" includes the exclusive and closed term "consist". Furthermore, in this description, the terms "essentially" or "substantially" correspond to an approximation of ± 30%, preferably ± 20%, very preferably ± 10%.

[0034] The present invention relates to a lithium adsorption extraction method using a simulated countercurrent chromatography or simulated moving bed separation method, which we will hereinafter generally refer to as the "LMS" method. The lithium adsorption extraction method using simulated countercurrent chromatography or simulated moving bed of the present application may use synchronous movement of the inlet / outlet lines, but may also use non-synchronous movement of the inlet / outlet valves in a multi-column 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. Subsequently, the cycle time refers to the time after which the injection and collection points have been sequenced until they return to the initial position in the device.At the end of a cycle, the device is back in its initial configuration. According to one or more embodiments, a cycle comprises as many periods as there are columns or beds of adsorbent solid in the separation loop. For example, a cycle of an “LMS” process according to the invention comprising 8 columns or 8 beds of adsorbent solid is produced from 8 periods.

[0035] According to the invention, the LMS method and device uses / comprises 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 adsorbent solid or granular medium, according to a flow direction of the fluid(s) implemented in the column(s). The fluid successively passing through the column(s) C i is called the main fluid to distinguish it from other secondary fluids which 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.

[0036] In reference to the figure 1, according to one or more embodiments, the method and the device according to the invention uses / comprises a plurality n of columns C i (i.e., from column C 1 to column C n ) separated by N distribution devices (of the feed F and the desorbent D) and collection devices (of the extract E and the raffinate R). Preferably, the number n of columns C i and the number N of distribution and collection devices are identical. 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 24, preferably between 8 and 21, eg between 12 and 15. 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 24, preferably between 8 and 21, eg between 12 and 15.

[0037] In reference to the figure 2, the method and the LMS device uses / comprises a column C 1 implementing the flow of fluids in 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 the secondary fluids which can be added to the main fluid via a distribution and collection device, also called a Pi tray, generally located between two successive beds of adsorbent solid Ai.

[0038] A Pi tray 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 which aims to distribute the fluid resulting from the mixing of the main fluid and the secondary fluids on the granular bed located immediately downstream, in the direction of flow of the main fluid.

[0039] In reference to the figure 2, a column is divided into a plurality of Pi trays and Ai adsorbent solid beds, the Pi tray being arranged directly upstream of the Ai adsorbent bed, in the direction of flow of the main fluid. In addition, an Ai+1 adsorbent bed is referred to as the next adsorbent bed located downstream of the Ai adsorbent bed, in the direction of flow of the main fluid. Similarly, a Pi+1 tray designates the next tray located downstream of the Pi tray, in the direction of flow of the main fluid.

[0040] According to one or more embodiments, the method and the device according to the invention uses / comprises at least one separation column C i divided into n beds of adsorbent solid A i separated by N trays (defining inter-bed zones), each tray being itself able to be divided into several sectors or regions, called panels. Preferably, the number n of beds of adsorbent solid A i and the number N of trays P i are identical. 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 24, preferably between 8 and 21, eg between 12 and 15. According to one or more embodiments, N is between 4 and 24, preferably between 8 and 21, eg between 12 and 15.

[0041] In the rest of the text, we speak of a step to designate an operation or a group of similar operations carried out on a given flow at a certain point in the process. The process is described in its different steps taken in the order of flow of the flows or products.

[0042] The process for extraction by adsorption of lithium in a simulated moving bed according to the invention comprises the following step: one or more columns C i are fed with at least one feed F comprising lithium and a desorbent D, and at least one extract E and at least one raffinate R are withdrawn from column C i, the column(s) C i comprising an adsorbent solid comprising at least one lithiated aluminum oxyhydroxide AIO(OH) and / or at least one lithiated aluminum hydroxide Al(OH) 3.

[0043] In reference to the figure 1 , according to one or more embodiments, the adsorbent solid is distributed in a plurality of columns C i (eg adsorbers).

[0044] In reference to the figure 2 , according to one or more embodiments, the adsorbent solid is distributed in beds of adsorbent solid A i of at least one column C i , the beds of adsorbent solid A i being separated by trays P i .

[0045] According to the invention, the at least one column C i is interconnected in a closed loop, the feed and withdrawal points of the column(s) C i being offset over time (for example by a value corresponding to a column (e.g. adsorber) or an adsorbent bed of a column) with a permutation period and determining a plurality of operating zones of the column(s) C i , and in particular the following main zones designated by definition by a number: a lithium desorption zone I between an injection point of the desorbent D and a withdrawal point of the extract E; a zone II for desorption of alkali metals other than lithium and / or alkaline earth metals between the withdrawal point of the extract E and an injection point of the feedstock F comprising lithium; a lithium adsorption zone III between the injection point of the feedstock F and a withdrawal point of the raffinate R; and a zone IV is between the withdrawal point of the raffinate R and the injection point of the desorbent D;

[0046] In reference to the figure 1 , according to one or more embodiments, the feed and withdrawal points of the columns C i are shifted over time by a value corresponding to a column C i (eg an adsorber).

[0047] In reference to the figure 2, according to one or more embodiments, the feed and withdrawal points of the at least one column C i are shifted over time by a value corresponding to an adsorbent bed A i .

[0048] Advantageously, the process according to the invention allows the 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), present in significant quantities in the saline solutions treated in said extraction process. The process according to the invention also allows the selective separation of lithium from other compounds such as boron and sulfates.

[0049] In particular, the process according to the invention makes it possible to produce a lithium-concentrated extract compared to conventional processes. A lithium concentration factor greater than 10 between the charge and the extract is achievable by the process according to the invention, whereas conventional processes have a ceiling of 3 or 4. The counter-current practiced by the process according to the invention allows an advantageous accumulation zone for concentrating the lithium in the extract.

[0050] According to one or more embodiments, the at least one column C i comprises a plurality of columns or adsorbers interconnected in a closed loop. According to one or more embodiments, the feed and withdrawal points of the columns C i or adsorbers are offset over time by a value corresponding to a column or a bison. According to one or more embodiments, the plurality of columns C i or adsorbers comprises at least 4 columns or adsorbers, preferably between 4 and 24 columns or adsorbers, preferably between 8 and 21 columns or adsorbers, eg between 12 and 15 columns or adsorbers.

[0051] According to one or more embodiments, the adsorbent solid is distributed in zones I to IV according to configurations known as type a / b / c / d, that is to say that the distribution of the adsorbent solid, relative to the total quantity of adsorbent solid, is as follows: a is the quantity of adsorbent solid in zone I; b is the quantity of adsorbent solid in zone II; c is the quantity of adsorbent solid in zone III; and d is the quantity of adsorbent solid in zone IV, process in which: a = 43 % ± 9 % , preferably ± 6%, very preferably ± 3%; b = 29 % ± 6 % ; preferably ± 4%, very preferably ± 2%; c = 14 % ± 3 % , preferably ± 2%, very preferably ± 1%; and d = 14 % ± 3 , preferably ± 2%, very preferably ± 1%.

[0052] According to one or more embodiments, the at least one column C i comprises a plurality of beds of adsorbent solid A i interconnected in a closed loop and separated by trays P i , the feed and withdrawal points in the trays P i of the column C i being offset over time by a value corresponding to an adsorbent bed. According to one or more embodiments, the at least one column C i comprises between 4 and 24 beds of adsorbent solid A i , preferably between 8 and 21 beds of adsorbent solid A i . eg between 8 and 21 beds of adsorbent solid A i .

[0053] According to one or more embodiments, the beds of adsorbent solid A i are distributed in zones I to IV according to configurations known as type a / b / c / d, that is to say that the distribution of the beds of adsorbent solid A i is as follows: a is the number of beds in zone I; b is the number of beds in zone II; c is the number of beds in zone III; and d is the number of beds in zone IV, process in which: a = t * 0 , 43 * 1 ± 0 , 20 , préférablement 1 ± 0,10 , très préférablement 1 ± 0,05 ; b = t * 0 , 29 * 1 ± 0 , 20 , préférablement 1 ± 0,10 , très préférablement 1 ± 0,05 ; c = t * 0 , 14 * 1 ± 0 , 20 , préférablement 1 ± 0,10 , très préférablement 1 ± 0,05 ; And d = t * 0 , 14 * 1 ± 0 , 20 , préférablement 1 ± 0,10 , très préférablement 1 ± 0,05 , method in which t is a natural integer between 4 and 24, preferably between 8 and 21, such as between 12 and 15.

[0054] According to one or more embodiments, the temperature is adjusted so that the temperature in the adsorbent solid remains at a temperature of between 0°C and 120°C and preferably between 5°C and 100°C, particularly preferably between 15°C and 80°C, very preferably between 40°C and 80°C, in particular to promote accelerated drilling of the adsorbent solid.

[0055] Advantageously, the pressure is adjusted so that the liquid phase remains at all points in 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.

[0056] According to one or more embodiments, a portion of the extract E or a stream obtained by concentration and / or purification of said extract is fed into zone II, preferably into a central portion of zone II, very preferably substantially in the middle of zone II, in particular in order to improve the concentration of the extract. In the present application, the term "roughly in the middle of zone II, » zone II comprising a quantity X of adsorbent solid, corresponds to a position arranged between 0.35*X and 0.65*X of adsorbent solid, preferably between 0.40*X and 0.60*X of adsorbent solid, very preferably between 0.45*X and 0.55*X of adsorbent solid.

[0057] According to one or more embodiments, at least 1% of the extract E or a stream obtained by concentration and / or purification of said extract, preferably at least 5% of the extract E or a stream obtained by concentration and / or purification of said extract, very preferably at least 10% of the extract E or a stream obtained by concentration and / or purification of said extract, is fed into zone II. According to one or more embodiments, between 5% and 20% of the extract E or a stream obtained by concentration and / or purification of said extract, is fed into zone II.

[0058] According to one or more embodiments, the cycle duration is at least 20 min, preferably at least 40 min, such as between 1 hour and 10 hours. Preferably, the cycle duration used is between 2 hours and 8 hours. The cycle duration corresponds to the permutation period ST (period between two successive permutations of the feeds / extractions) multiplied by the total number of injection / withdrawal points, such as the total number of columns C i used (see example of the figure 1 ) or beds of adsorbent solid A i used (see example of the figure 2 ).

[0059] According to one or more embodiments, the recycling rate (i.e. ratio of the average recycling flow rate (average of the zone flow rates weighted by the number of columns or beds of adsorbent solid per zone) to the load flow rate) is between 2 and 12, preferably between 3 and 9, very preferably between 5 and 8.

[0060] According to one or more embodiments, the volume flow rate ratio of the desorbent to the volume flow rate of the feed is less than 1, preferably less than 0.5, preferably less than 0.2, very preferably less than 0.1. According to one or more embodiments, the volume flow rate ratio of the desorbent to the volume flow rate of the feed is between 0.01 and 1.0, preferably between 0.02 and 0.5, very preferably between 0.06 and 0.1.

[0061] According to one or more embodiments, the method according to the invention advantageously comprises a step of activating the adsorbent solid. Said activation step makes it possible to activate the sites intended to selectively adsorb lithium. Preferably, said activation step is advantageously carried out by passing an activation solution chosen from water and a lithium salt solution having a concentration of between 0.001 mol / L and 0.1 mol / L, preferably between 0.001 mol / L and 0.05 mol / L and more preferably between 0.01 and 0.04 mol / L. Preferably, the lithium salt used in solution in said activation step is chosen from lithium chloride (LiCl), lithium nitrate and lithium bromide. Very preferably, the lithium salt used in solution in said activation step is lithium chloride (LiCl).According to one or more embodiments, said activation step is carried out at a temperature between 0°C and 90°C, and preferably between 10°C and 60°C, and more preferably between 10°C and 30°C with a residence time of said activation solution in the column preferably between 0.03 and 10 h, and preferably between 0.06 and 1 h. According to one or more embodiments, the volume of activation solution is between 1 and 30 times, preferably between 2 and 20 times, the total volume of adsorbent.

[0062] The simulated moving bed lithium adsorption extraction device includes the following elements: at least one column (C i ) adapted to be fed with at least one feed comprising lithium and a desorbent, and to be withdrawn from at least one extract and at least one raffinate from the column (C i ), the at least one column (C i ) comprising an adsorbent solid comprising at least one lithiated aluminum oxyhydroxide AIO(OH) and / or at least one lithiated aluminum hydroxide Al(OH) 3, the at least one column (C i ) being interconnected in a closed loop, the feed and withdrawal points of the at least one column (C i ) being offset over time by a value corresponding to a predetermined amount of adsorbent solid with a permutation period and determining the plurality of zones I, II, III and IV as defined above.

[0063] According to one or more embodiments, the feed and draw-off points of the at least one column (C i ) are shifted synchronously.

[0064] According to one or more embodiments, the feed and draw-off points of the at least one column (C i ) are shifted asynchronously. In this case, the cycle duration designates the time after which the injection and collection points have been sequenced until returning to the initial position in the device. The quantity of adsorbent solid contained in each of zones I, II, III and IV as defined above is then calculated as being the average quantity of adsorbent solid contained respectively in each of the zones over the duration of the cycle. In the same way, the number of beds in each of zones I, II, III and IV as defined above is calculated as being the average number of adsorbent beds contained respectively in each of the zones over the duration of the cycle, this value possibly being non-integer.

[0065] 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.

[0066] According to one or more embodiments, the filler comprises at least one of the following elements: Na, K, Rb, Cs, Mg, Ca, Sr, Ba, F, Cl, Br, I, SO 4 , CO 3 , NO 3 , B and HCO 3 .

[0067] Said feedstock may be any natural saline solution, concentrated or derived from a lithium extraction or transformation process. For example, said saline solution used in the extraction process according to the invention may advantageously be chosen from brines from salt lakes or geothermal sources, brines subjected to evaporation to obtain lithium-concentrated brines, seawater, effluents from lithium chloride or hydroxide production plants and effluents from lithium extraction processes from minerals.

[0068] According to one or more embodiments, the charge comprises at least 0.1 g / L weight of lithium element, preferably in the form of LiCl, relative to the total weight of the charge. According to one or more embodiments, the charge comprises between 0.1 g / L and 1 g / L of lithium element, preferably in the form of LiCl, relative to the total weight of the charge.

[0069] According to one or more embodiments, the desorbent is selected from the group consisting of water, lithiated water, brine, preferably water. 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 0.05 g / L of lithium element, preferably less than 0.01 g / L of lithium element, relative to the total weight of the desorbent.

[0070] According to one or more embodiments, the at least one lithiated aluminum oxyhydroxide AIO(OH) comprises lithiated boehmite. According to one or more embodiments, the at least one lithiated aluminum oxyhydroxide AIO(OH) comprises at least 60% by weight, preferably at least 80% by weight, of lithiated boehmite, relative to the total weight of the at least one lithiated aluminum oxyhydroxide AIO(OH). According to one or more embodiments, the at least one lithiated aluminum oxyhydroxide AIO(OH) consists of lithiated boehmite.

[0071] According to one or more embodiments, the at least one lithiated aluminum hydroxide Al(OH) 3 comprises lithiated bayerite. According to one or more embodiments, the at least one lithiated aluminum hydroxide Al(OH) 3 comprises at least 60% by weight, preferably at least 80% by weight, of lithiated bayerite, relative to the total weight of the at least one lithiated aluminum hydroxide Al(OH) 3. According to one or more embodiments, the at least one lithiated aluminum hydroxide Al(OH) 3 consists of lithiated bayerite.

[0072] According to one or more embodiments, the adsorbent solid comprises at least 0.1% by weight of lithium element (preferably in the form of LiCl), preferably at least 1% by weight, very 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 element (preferably in the form of LiCl), preferably between 1% by weight and 4% by weight, very preferably between 1.5% by weight and 3% by weight, relative to the total weight of the adsorbent solid.

[0073] 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, wherein 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, very preferably between 0.1 and 0.5.

[0074] 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 m 2 < / g and 30 m 2 < / g, preferably between 1 m 2 < / g and 20 m 2 < / g.

[0075] According to one or more embodiments, the adsorbent solid is in the form of balls or extrudates of cylindrical, hollow cylinder, cartwheel, trilobed or multilobed shape or any other geometric shape used by a person skilled in the art. According to one or more embodiments, the adsorbent solid is in the form of balls with an average diameter of between 0.1 and 1.5 mm, preferably between 0.1 and 1 mm, more preferably between 0.1 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 and 5 mm, preferably between 0.2 and 3 mm, more preferably between 0.25 and 1.8 mm.

[0076] The solid adsorbent material is characterized using the following techniques: nitrogen adsorption for the determination of the specific surface area using the BET method (e.g. ASTM D 3663-7 standard); 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 estimation of the number-average diameter of the adsorbent solid is carried out using an analysis of the particle size distribution of a sample of at least 50 adsorbent beads by imaging according to ISO 13322-2:2006 using a conveyor belt allowing 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: Example 1 (in accordance with the invention): Separation of a brine with simulated counter-current.

[0077] The process according to the invention is applied for the purification and separation of a lithium brine of the following composition: 0.4 g / L in lithium element; 110 g / L in chlorine element; 70 g / L in sodium element.

[0078] The adsorbent solid considered for separation is a lithiated bayerite.

[0079] The process uses a C 1 column comprising 21 beds of adsorbent solid A i distributed as follows: 9 beds in zone 1; 6 beds in zone 2; 3 beds in zone 3; 3 beds in zone 4.

[0080] Separation takes place at 20°C. The desorbent is water containing no lithium element. The desorbent / load flow rate ratio is 0.08 and the average recycling rate is 7.3. The surface velocity in zone 3 is 0.5 cm / s.

[0081] The process performance is calculated by simulation. Thermodynamic and mass transfer data were previously obtained by drilling tests, as commonly performed by those skilled in the art. The concentration profile calculated along the simulated moving bed is presented in Figure 3 .

[0082] The results indicate an extract concentration of 4.4 g / L, or a concentration factor of 11. This high concentration significantly reduces the equipment and energy consumption required for water evaporation in the downstream stages of the process.

[0083] Furthermore, the purity of lithium, defined as the ratio of the mass of lithium to the cumulative mass of sodium and lithium, is 99.9%. Example 2 (not in accordance with the invention): Separation of a brine without simulated countercurrent

[0084] In example 2, a brine identical to example 1 is separated by a 20°C adsorption process on a lithiated bayerite identical to example 1. On the other hand, the process implemented is operated in a batch manner and without the installation of a simulated counter-current.

[0085] The final product has a final concentration of 1.2 g / L of lithium element. The concentration factor obtained is equal to 3 and is significantly lower than the case with simulated counter-current.

[0086] The process according to the invention allows the production of a much more concentrated flow than with a standard batch adsorption process.

Claims

1. Simulated moving-bed lithium adsorption extraction process comprising the following step: - feeding at least one column (Ci) with at least one feed (F) comprising lithium and with a desorbent (D), and withdrawing at least one extract (E) and at least one raffinate (R) from the column (Ci), the at least one column (Ci) comprising a solid adsorbent comprising at least one lithiated aluminium oxyhydroxide AIO(OH) and / or at least one lithiated aluminium hydroxide Al(OH)3, the at least one column (Ci) being interconnected in a closed loop, the feeding and withdrawal points of the at least one column (Ci) being shifted over time by a value corresponding to a predetermined amount of solid adsorbent having a switchover time, and a plurality of operating zones of the column (Ci) being defined, in particular the main zones below designated numerically as follows: - a zone I of lithium desorption between a point of injection of the desorbent and a point of withdrawal of the extract; - a zone II of desorption of alkali metals other than lithium and / or of alkaline earth metals between the point of withdrawal of the extract and a point of injection of the lithium-containing feed; - a zone III of lithium adsorption between the point of injection of the feed and a point of withdrawal of the raffinate; and - a zone IV between the point of withdrawal of the raffinate and the point of injection of the desorbent.

2. Process according to Claim 1, wherein the at least one column (Ci) comprises a plurality of columns (Ci) or adsorbers interconnected in a closed loop, the feeding and withdrawal points of the columns (Ci) or adsorbers being shifted over time by a value corresponding to a column (Ci) or an adsorber.

3. Process according to Claim 1 or Claim 2, wherein the plurality of columns (Ci) or adsorbers comprises at least 4 columns or adsorbers.

4. Process according to any one of the preceding claims, wherein the solid adsorbent is distributed in zones I to IV according to configurations referred to as type a / b / c / d configurations, that is to say the distribution of the solid adsorbent relative to the total amount of solid adsorbent is as follows: - a is the amount of solid adsorbent in zone I; - b is the amount of solid adsorbent in zone II; - c is the amount of solid adsorbent in zone III; and - d is the amount of solid adsorbent in zone IV, in which process: - a = 43 % ± 9 % ; - b = 29 % ± 6 % ; - c = 14 % ± 3 % ; and - d = 14 % ± 3 % .

5. Process according to Claim 1, wherein the at least one column (Ci) comprises a plurality of beds of solid adsorbent (Ai) interconnected in a closed loop and separated by plates (Pi), the feeding and withdrawal points in the plates (Pi) of the column (Ci) being shifted over time by a value corresponding to a bed of adsorbent.

6. Process according to Claim 5, wherein the at least one column (Ci) comprises between 4 and 24 beds of solid adsorbent (Ai).

7. Process according to Claim 5 or Claim 6, wherein the beds of solid adsorbent (Ai) are distributed in zones I to IV according to configurations referred to as type a / b / c / d configurations, that is to say the distribution of the beds of solid adsorbent (Ai) is as follows: - a is the number of beds in zone I; - b is the number of beds in zone II; - c is the number of beds in zone III; and - d is the number of beds in zone IV, in which process: - a = t * 0.43 * 1 ± 0.20 ; - b = t * 0.29 * 1 ± 0.20 ; - c = t * 0.14 * 1 ± 0.20 ; and - d = t * 0.14 * 1 ± 0.20 , in which process t is a natural integer between 4 and 24.

8. Process according to any one of the preceding claims, wherein a portion of the extract (E) or a stream obtained by concentrating and / or purifying said extract (E) is fed to zone II.

9. Process according to any one of the preceding claims, wherein the solid adsorbent comprises lithiated bayerite and / or lithiated boehmite.

10. Process according to any one of the preceding claims, wherein the solid adsorbent comprises between 0.1% by weight and 5% by weight of the element lithium relative to the total weight of the solid adsorbent.

11. Process according to any one of the preceding claims, wherein the solid adsorbent comprises a solid material of formula (LiCl)x·2Al(OH)3·nH2O, where n is between 0.01 and 10 and x is between 0.4 and 1.

12. Process according to any one of the preceding claims, wherein the feed (F) comprises at least 0.1 g / L by weight of the element lithium relative to the total weight of the feed.

13. Process according to any one of the preceding claims, wherein the steps of the process are carried out at a temperature of between 0°C and 120°C.

14. Process according to any one of the preceding claims, wherein the ratio of the volume flow rate of the desorbent (D) to the volume flow rate of the feed (F) is less than 1.

15. Simulated moving-bed lithium adsorption extraction apparatus comprising the following elements: - at least one column (Ci) suitable for being fed with at least one feed (F) comprising lithium and with a desorbent (D) and for the withdrawal of at least one extract (E) and at least one raffinate (R) from the column (Ci), the at least one column (Ci) comprising a solid adsorbent comprising at least one lithiated aluminium oxyhydroxide AIO(OH) and / or at least one lithiated aluminium hydroxide Al(OH)3, the at least one column (Ci) being interconnected in a closed loop, the feeding and withdrawal points of the at least one column (Ci) being shifted over time by a value corresponding to a predetermined amount of solid adsorbent having a switchover time, and a plurality of operating zones of the column (Ci) being defined, in particular the main zones below designated numerically as follows: - a zone I of lithium desorption between a point of injection of the desorbent and a point of withdrawal of the extract; - a zone II of desorption of alkali metals other than lithium and / or of alkaline earth metals between the point of withdrawal of the extract and a point of injection of the lithium-containing feed; - a zone III of lithium adsorption between the point of injection of the feed and a point of withdrawal of the raffinate; and - a zone IV between the point of withdrawal of the raffinate and the point of injection of the desorbent.