Method and device for extracting lithium by adsorption in a three-zone simulated moving bed
The simulated moving bed lithium adsorption process with three zones and eluate recycling addresses inefficiencies in existing lithium extraction by reducing desorbent use and impurities, achieving high lithium concentration and energy savings.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- IFP ENERGIES NOUVELLES
- Filing Date
- 2025-12-05
- Publication Date
- 2026-06-25
AI Technical Summary
Existing lithium extraction processes are inefficient, consume excessive desorbent, and produce low-yield lithium concentrates with high impurity levels, necessitating additional purification steps and energy-intensive evaporation.
A simulated moving bed lithium adsorption process with three zones, incorporating two-stage permutation periods and eluate recycling, reduces desorbent consumption, enhances lithium concentration, and minimizes impurities by employing a specific adsorbent distribution and controlled fluid flow.
The process achieves high lithium concentration with reduced impurities, minimizing the need for downstream purification and energy consumption, while effectively separating lithium from other alkali and alkaline earth metals.
Smart Images
Figure EP2025085627_25062026_PF_FP_ABST
Abstract
Description
[0001] Method and device for lithium adsorption extraction in a simulated moving bed consisting of three zones
[0002] technical field
[0003] 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.
[0004] Previous technique
[0005] Demand for lithium has increased sharply in recent years, largely due to the rise of electric vehicles. To meet this demand, improving existing lithium extraction processes is essential. Lithium can be extracted from rocks or brines. In the case of brines, traditional processes are based on open-air evaporation, a slow and low-yield method. Adsorption processes have recently been developed and offer promising prospects.
[0006] Patent FR3053264B1 describes the preparation of a lithium selective adsorbent of formula (LiCl) x .2Al(OH)3,nH2O with n ranging from 0.01 to 10, x ranging from 0.4 to 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, the column then being fed with a desorbent (eluent) to desorb the desired lithium.
[0007] Patent application FR3131225A1 describes a process for lithium adsorption extraction in a simulated moving bed.
[0008] Summary of the invention
[0009] In the context described above, a first objective of this description is to overcome the problems of the prior art and to provide a process and device for lithium adsorption extraction that limits the consumption of desorbent in the process in order to limit its environmental impact.
[0010] A second objective of this description is to increase the lithium concentration in the extract. A high lithium concentration in the extract allows, in particular, a reduction in the amount of water to be evaporated or separated later in the process, thus simplifying the extraction equipment and resulting in significant energy savings.
[0011] A third objective of this 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 adsorption extraction.
[0012] Advantageously, the applicant identified that simulated moving bed lithium adsorption processes and devices 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).
[0013] 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 comprising between the desorbent injection point and a withdrawal point for an eluate and an extract; a zone II comprising between the raffinate withdrawal point and the desorbent injection point; and a lithium adsorption zone III comprising between the load injection point and a raffinate withdrawal point, in which each permutation period comprises two steps: a first step A during which the eluate is withdrawn from zone I; and a second step B during which the extract is withdrawn from zone I.
[0014] According to one or more embodiments, the eluate is recycled at least partially in zone III.
[0015] According to one or more embodiments, the eluate is recycled at least partially at the feed injection point. According to one or more embodiments, the recycling rate is between 2 and 12, preferably between 3 and 9, and 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.
[0016] 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, most preferably between 0.2 and 0.5.
[0017] According to one or more embodiments, at least one column comprises a plurality of columns or adsorbers, the supply and withdrawal points of the columns or adsorbers being shifted over time by a value corresponding to one column or adsorber.
[0018] 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.
[0019] 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 adsorbent solid in zone II; and c is the percentage of adsorbent solid in zone III, 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%.
[0020] According to one or more embodiments, a is approximately equal to 40%, b is approximately equal to 20% and c is approximately equal to 40%.
[0021] In one or more embodiments, the at least one column comprises a plurality of beds of adsorbent solid separated by trays, the feeding and withdrawal points in the column trays being offset over time by a value corresponding to one bed of adsorbent. In 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.
[0022] According to one or more embodiments, the adsorbent solid comprises and preferably consists of lithium bayerite and / or lithium boehmite.
[0023] 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.
[0024] 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.
[0025] According to one or more embodiments, the permutation period is between 500 seconds and 10000 seconds, preferably between 1000 seconds and 5000 seconds.
[0026] According to one or more embodiments, step A is carried out for at least 30% and preferably at least 40% of the permutation period.
[0027] 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.
[0028] According to one or more embodiments, the adsorbent solid comprises at least one lithiaated aluminium oxyhydroxide Al0(OH) and / or at least one lithiated aluminium hydroxide Al(OH)3.
[0029] 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.
[0030] According to one or more embodiments, the desorbent is chosen from the group consisting of water, lithia water, brine, preferably water.
[0031] 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 process steps 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 penetration of the adsorbent solid.
[0032] 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 adsorbent solid beds is between 0.09 MPa and 5 MPa, preferably between 0.095 MPa and 3.5 MPa, and preferably between 0.1 MPa and 2.5 MPa.
[0033] 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 of at least one raffinate and at least one extract and of the column, the at least one column comprising an adsorbent solid, the feeding and withdrawal points of the 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 principal zones designated by definition by a number: a lithium desorption zone I comprising the desorbant injection point and a withdrawal point of an eluate and the extract;a zone II comprising between the raffinate withdrawal point and the desorbent injection point; and a lithium adsorption zone III comprising 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.;
[0034] Other features and advantages of the invention, according to the aforementioned aspects, will become apparent from the following description and non-limiting examples of implementations, with reference to the figures attached and described below.
[0035] List of figures
[0036] Figure 1 illustrates a simulated moving bed lithium adsorption extraction process according to the invention, using a plurality of columns. Figure 2 illustrates 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.
[0037] Figure 3 shows a simulated moving bed lithium adsorption extraction process according to the invention featuring a first two-stage permutation period.
[0038] Figure 4 shows the process according to Figure 3, presenting a second two-step permutation period.
[0039] Figure 5 shows a simulated moving bed lithium adsorption extraction process according to the invention with eluate recycling.
[0040] Description of the implementation methods
[0041] 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.
[0042] In this application, the term "include" is synonymous with (means the same as) "include" and "contain," and is inclusive or open-ended, not excluding 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%, and most preferably ±5%.
[0043] 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 consists of 8 periods.
[0044] 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) Ci, 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., the main fluid successively passes through columns Ci through C nand is recycled from column C n to column Ci.
[0045] With reference to Figure 1, according to one or more embodiments, the method and device according to the invention uses / complies with a plurality n of columns (in this example, from column Ci to column Cs), each column comprising dispensing devices (for the charge F and the desorbent D) and collection devices (for the raffinate R, the eluent Ei, and the extract E2). 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.
[0046] Referring to Figure 2, the LMS process and apparatus uses / includes a column Ci implementing the flow of fluids through a plurality of beds of adsorbent solid Ai arranged in series according to the 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 Pi, generally located between two successive beds of adsorbent solid Ai. A tray Pj includes 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 includes at least one distribution zone which is intended to distribute the fluid resulting from the mixing of the main fluid and secondary fluids onto the granular bed located immediately downstream, in the direction of the main fluid flow.
[0047] Referring to Figure 2, a column is divided into a plurality of trays Pj and adsorbent beds Aj, with tray Pj positioned directly upstream of the adsorbent bed Aj, in the direction of the main fluid flow. Furthermore, the adsorbent bed is referred to as A i+i to designate the next adsorbent bed located downstream of the adsorbent bed Aj, in the direction of the main fluid flow. Similarly, a plate P i+idesignates the next platform located downstream of platform Pj, in the direction of the main fluid flow. According to one or more embodiments, the beds of adsorbent solid Aj are interconnected in a closed loop, i.e., the main fluid is recycled from the bed of adsorbent solid A n to the bed of solid adsorbent Ai.
[0048] 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 Aj 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.
[0049] In the following text, the term "step" refers to an operation or group of similar operations performed on a given flow at a specific point in the process. The process is described in its various steps, taken in the order in which the flows or products occur.
[0050] The simulated moving bed lithium adsorption extraction process according to the invention comprises the following step: one or more column(s) Ci 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.
[0051] Referring to Figure 1, in one or more embodiments, the adsorbent solid is distributed in a plurality of columns Ci (e.g., adsorbers). Referring to Figure 2, in one or more embodiments, the adsorbent solid is distributed in beds of adsorbent solid Ai in at least one column Ci, the beds of adsorbent solid Ai being separated by trays Pi.
[0052] With reference to Figure 3, the process according to the invention proposes to implement a simulated countercurrent consisting of three zones: zone III, located between the injection of charge F and the withdrawal of raffinate R; zone II, located between the withdrawal of raffinate R and the injection of the desorbent (or eluent) D; and zone I, located between the injection of the desorbent and the withdrawal of eluate E1 or extract E2. In this example, the device comprises 5 columns, and during the first permutation period ST, charge F is injected at the inlet of column C1, raffinate is withdrawn at the outlet of column C2, desorbent D is injected at the inlet of column C3, and eluate E1 and extract E2 are withdrawn at the outlet of column C5.Referring to Figure 4, after a period of ST permutation, the charge F is injected into the inlet of column C2, the raffinate is withdrawn from the outlet of column C3, the desorbent D is injected into the inlet of column C4 and the eluate E1 and the extract E2 are withdrawn from 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 stage A during which a flow of eluate E1 is withdrawn from (end of) zone I; and a stage 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 value corresponding to one 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) Ci, and in particular the following main zones designated by definition by a number: a lithium desorption zone I between the desorbent injection point D and a withdrawal point of an eluate E1 and extract E2; a zone II between the raffinate withdrawal point R and the desorbent injection point D; and a lithium adsorption zone III 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 is withdrawn from zone I; and a second step B during which the extract is withdrawn from zone I.
[0055] Advantageously, the process according to the invention makes it possible to limit the consumption of desorbent in the process, thereby reducing its environmental impact. Furthermore, the process according to the invention makes it possible to increase the lithium concentration in extract E2.
[0056] Furthermore, the process according to the invention allows for the production of an E2 extract with a particularly low impurity content. Indeed, the process according to the invention enables enhanced 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 enables 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 Figure 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 charge F.
[0060] With reference to figure 3, according to one or more embodiments, the feed and withdrawal points of the columns Ci are shifted over time by a value corresponding to a column Ci (e.g. an adsorber).
[0061] With reference to Figure 2, according to one or more embodiments, the feed and withdrawal points of at least one column Ci are shifted over time by a value corresponding to an adsorbent bed Ai.
[0062] According to one or more embodiments, the adsorbent solid is distributed in zones I to III according to configurations of type a / b / c, that is to say that 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, 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 approximately equal to 40%, b is approximately equal to 20% and c is approximately 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, and preferably between 0.1 MPa and 2.5 MPa.
[0066] According to one or more embodiments, the main fluid passes through the columns Ci and / or the beds of adsorbing solid Ai 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 that it is 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 Figure 1) or of beds of adsorbent solid Ai used (see example in Figure 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] In one or more embodiments, step A is performed for at least 30%, and preferably at least 40%, of the permutation period ST. In one or more embodiments, step A is performed for between 30% and 60%, preferably between 40% and 50%, of the permutation period ST. In one or more embodiments, step A is performed for less than 50% of the permutation period ST. In 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. In 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 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, most preferably between 0.2 and 0.5.
[0072] According to one or more embodiments, the supply and withdrawal points of 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 positions 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 may be a 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. 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 of 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.
[0076] 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.
[0077] In one or more embodiments, the desorbent is selected from the group consisting of water, lithium-containing water, or brine, preferably lithium-containing brine. In one or more embodiments, the desorbent comprises between 0 g / L and 1 g / L of lithium, preferably in the form of LiCl, relative to the total weight of the desorbent. In one or more embodiments, the desorbent comprises less than 0.005 g / L of lithium, preferably less than 0.01 g / L of lithium, relative to the total weight of the desorbent.
[0078] According to one or more embodiments, the adsorbent comprises at least one lithiaated aluminium oxyhydroxide Al0(OH) and / or at least one lithiated aluminium hydroxide Al(OH)3.
[0079] In one or more embodiments, the at least one lithiased aluminum oxyhydroxide Al₂O₃(OH)₂ comprises lithiased boehmite. In one or more embodiments, the at least one lithiased aluminum oxyhydroxide Al₂O₃(OH)₂ 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)₂. In one or more embodiments, the at least one lithiased aluminum oxyhydroxide Al₂O₃(OH)₂ consists of lithiased boehmite.
[0080] In one or more embodiments, the at least one lithium aluminum hydroxide Al(OH)3 comprises lithium bayerite. In one or more embodiments, the at least one lithium aluminum hydroxide Al(OH)3 comprises at least 60% by weight, preferably at least 80% by weight, of lithium bayerite, relative to the total weight of the at least one lithium aluminum hydroxide Al(OH)3. In one or more embodiments, the at least one lithium aluminum hydroxide Al(OH)3 consists of lithium bayerite. In 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, 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 element (preferably in the form of LiCl), preferably between 1% by weight and 4% by weight, most preferably between 1.5% by weight and 3% by weight, relative to the total weight of the adsorbent solid.
[0081] 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. 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.
[0082] According to one or more embodiments, the adsorbent solid has a specific surface area characterized by nitrogen adsorption according to the BET method, between 1 m 2 / g and 30 m 2 / g, preferably between 1 m 2 / g and 20 m2 / g.
[0083] In one or more embodiments, the adsorbent solid is in the form of beads or extrudates of cylindrical, hollow cylinder, wheel-shaped, trilobed, or multilobed shape, or any other geometric shape understood by those skilled in the art. In 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. In 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.
[0084] 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 optically on at least 10 extrudates, preferably at least 50. For example, when the solid adsorbent is in the form of beads, the number-average diameter of the adsorbent is estimated by analyzing the particle size distribution of a sample of at least 50 adsorbent beads using imaging according to ISO 13322-2:2006, with 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.
[0085] Examples:
[0086] The process according to the invention is applied for the purification and separation of a lithium brine comprising:
[0087] 0.4 g / L of lithium element;
[0088] 110 g / L as elemental chlorine;
[0089] 70 g / L as elemental sodium.
[0090] The adsorbent considered for the separation is a lithium bayerite.
[0091] The process temperature is 20°C.
[0092] The desorbent is water containing 0.15 g / L of lithium element.
[0093] The simulated moving bed lithium adsorption extraction device comprises 5 C1-C5 columns, each with an adsorbent bed 1m long and 1.25cm in inner radius.
[0094] The cycle used is the one with recycling of the eluate Ei at the inlet in zone III during step A, as shown in figure 5.
[0095] The distribution of beds by zone is as follows:
[0096] 2 beds in zone I (i.e. 40% of the adsorbent solid);
[0097] 1 bed in zone II (i.e., 20% of the adsorbent solid); and
[0098] 2 beds in zone III (i.e. 40% of the solid adsorbent).
[0099] The beds are traversed in downward mode for the adsorption and elution phases.
[0100] Step A lasts 1300 seconds. Step B lasts 1400 seconds.
[0101] The charge flow rate F is 32.2 cm 3 / min during step A and 58 cm 3 / min during step B. The desorbent flow rate D is 20 cm 3 / min. The raffinate flow rate R is 52.2 cm 3 / min.
[0102] The flow rates of eluate Ei and extract E2 are 25.8 cm 3 / min.
[0103] The eluate Ei is directly injected with the charge F at the beginning of zone III during step A.
[0104] The lithium concentration of the extract is 1.61 g / L.
[0105] 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 a sorbent 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 absorbent 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 desorbent injection point (D) and a withdrawal point of an eluate (Ei) and the extract (E2); a zone II between the point of withdrawal of the raffinate (R) and the point of injection of the desorbent (D);and a lithium adsorption zone III comprising 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 (Ei) 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 feed and withdrawal points of the at least one column (Ci) 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 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 (E1) 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 (E1) connected to zone I, and a second extract outlet conduit (E2) connected to zone I.;