Method and device for simulated moving bed extraction by lithium adsorption
The simulated moving bed lithium adsorption process enhances lithium concentration and reduces impurities and desorbent consumption, addressing inefficiencies in existing methods by organizing adsorbents into zones I to IV, achieving high lithium concentration and energy savings.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- IFP ENERGIES NOUVELLES
- Filing Date
- 2021-12-23
- Publication Date
- 2026-07-10
Abstract
Description
Title of the invention: Method and device for simulated moving bed extraction by lithium adsorption 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 separation in a simulated moving bed. Previous technique
[0002] Lithium ions coexist with massive quantities of metals such as, for example, alkali metals, alkaline earth metals, boron, and sulfates, particularly in saline solutions such as brines. Therefore, they must be extracted economically and selectively from these saline solutions. Indeed, the chemical properties of lithium and alkali metals, preferably sodium (Na) and potassium (K), and alkaline earth metals, preferably magnesium (Mg), calcium (Ca), and strontium (Sr), make the separation of these elements difficult.
[0003] Solid materials based on aluminum oxyhydroxide Al₂O(OH)₂ and / or aluminum hydroxide Al₂O(OH)₃ are known for their use as adsorbents in the adsorption / desorption of lithium ions, and in particular in processes for extracting lithium from saline solutions by adsorption. Advantageously, these materials allow the intercalation of lithium atoms into their structure, thus enabling the extraction of lithium from a feedstock by adsorption and the production of a lithium-enriched extract by desorption using a desorbent.
[0004] Patent application FR 3053264 Al describes in particular a process for extracting lithium from saline solutions by adsorption, said process employing 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 makes it possible to obtain acceptable levels of lithium purification, the production of lithium by adsorption phenomena can be improved. Summary of the invention
[0006] In the context described above, a first objective of the present description is to overcome the problems of the prior art and to provide a method and device for lithium adsorption extraction that increases the concentration of lithium in the extract. The high concentration of lithium in the extract makes it possible, in particular, to reduce the amount of water to be evaporated or separated in the continuation 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 obtaining 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 adsorption extraction.
[0008] A third objective of this description is to limit the consumption of desorbent in the process in order to limit its environmental impact.
[0009] Advantageously, the applicant identified that solid lithia-based materials of aluminium oxyhydroxide A10(OH) and / or aluminium hydroxide Al (OH)3 were suitable for lithium adsorption extraction in a simulated moving bed separation process and device, or simulated countercurrent separation.
[0010] 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 charge 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 lithium aluminum oxyhydroxide Al10(OH) and / or at least one lithium aluminum hydroxide Al(OH)3, the at least one column being interconnected in a closed loop, 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 a desorbent injection point and an extract withdrawal point; - a zone II for the desorption of alkali metals other than lithium and / or alkaline earth metals located between the point of withdrawal of the extract and a point of injection of the charge including lithium; - a lithium adsorption zone III located between the charge injection point and a raffinate withdrawal point; and - a zone IV is included 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 supply and withdrawal points of the columns or adsorbers being shifted over time by a value corresponding to one 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 of type a / b / c / d, 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 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 solid adsorbent interconnected in a closed loop and 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.
[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 beds of solid adsorbent are distributed in zones I to IV according to so-called type a / b / c / d configurations, i.e. the distribution of the beds of solid adsorbent is as follows: - a is the number of beds in zone I; - b is the number of beds in zone II; - This 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 integer between 4 and 24, preferably between 8 and 21, for example between 12 and 15 beds of solid adsorbent.
[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 part of zone II, most 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 lithium bayerite and / or lithium 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,nH2O, 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, lithium 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 process 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, most preferably between 40°C and 80°C, in particular to promote accelerated perforation of the adsorbent solid.
[0025] Advantageously, the steps of the process are carried out at a controlled pressure (e.g., pressure in the adsorbent solid) so 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, and more preferably between 0.1 MPa and 2.5 MPa.
[0026] 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 hour and 10 hours. Preferably, the cycle duration is between 2 hours and 8 hours.
[0027] 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 0.5, preferably less than 0.2, very preferably less than 0.1.
[0028] 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 0.01 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 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 extract and at least one raffinate from the column, the at least one column comprising an adsorbent solid comprising at least one lithium aluminum oxyhydroxide Al(OH)3 and / or at least one lithium aluminum hydroxide Al(OH)3, the at least one column being interconnected in a closed loop, 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 a desorbent injection point and an extract withdrawal point; - a zone II for the desorption of alkali metals other than lithium and / or alkaline earth metals located between the point of withdrawal of the extract and a point of injection of the charge including lithium; - a lithium adsorption zone III located between the charge injection point and a raffinate withdrawal point; and - a zone IV is included between the point of withdrawal of the raffinate and the point of injection of the desorbent.
[0030] Other features and advantages of the invention according to the aforementioned aspects will become apparent from reading the description below and non-limiting examples of embodiments, with reference to the figures attached and described below. List of figures
[0031] Fig. 1 represents a simulated moving bed lithium adsorption extraction process according to the invention, using a plurality of columns or adsorbers.
[0032] 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.
[0033] Figure 3 shows the concentration profile calculated along a simulated moving bed lithium adsorption extraction column according to the invention. Description of embodiments
[0034] 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.
[0035] 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 ±30%, preferably ±20%, most preferably ±10%.
[0036] 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 of the present application may employ synchronous movement of the inlet / outlet lines, but may 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 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 in 8 periods.
[0037] According to the invention, the LMS method and device uses / comprising 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 column(s) C; 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)), g generally located at the beginning or end of a column, for example between two successive columns.
[0038] 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 C; (i.e., from column Ci to column Cn) separated by N dispensing devices (for the charge F and the desorbent D) and collection devices (for the extract E and the raffinate R). Preferably, the number n of columns C; and the number N of dispensing 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, e.g., 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, e.g., between 12 and 15.
[0039] 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 Pi, generally located between two successive beds of adsorbent solid Ai.
[0040] A tray Pi 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.
[0041] With reference to [Fig. 2], a column is divided into a plurality of trays Pi and adsorbent beds Ai, with tray Pi being located directly upstream of the adsorbent bed Ai, in the direction of the main fluid flow. Furthermore, the term adsorbent bed Ai+1 designates the next adsorbent bed located downstream of the adsorbent bed Ai, in the direction of the main fluid flow. Similarly, tray Pi+1 designates the next tray located downstream of tray Pi, in the direction of the main fluid flow.
[0042] According to one or more embodiments, the method and device according to the invention uses / comprising at least one separation column C; 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, denoted panels. Preferably, the number n of beds of adsorbent solid A; and the number N of trays P; 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, e.g., between 12 and 15. According to one or more embodiments, N is between 4 and 24, preferably between 8 and 21, e.g., between 12 and 15.
[0043] 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 of flow of the streams or products.
[0044] 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 extract E and at least one raffinate R are withdrawn from column Ci, the column(s) Ci comprising an adsorbent solid comprising at least one lithiaated aluminium oxyhydroxide AIO(OH) and / or at least one lithiated aluminium hydroxide A1(OH)3.
[0045] With reference to [Fig.1], according to one or more embodiments, the solid adsorbent is distributed in a plurality of columns C; (eg adsorbers).
[0046] 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;.
[0047] According to the invention, at least one column Ci is interconnected in a closed loop, the supply and withdrawal points of the column(s) C; being shifted over time (for example by a value corresponding to one column (e.g., adsorbent) or one 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 a desorbent injection point D and an extract withdrawal point E; - a zone II for the desorption of alkali metals other than lithium and / or alkaline earth metals located between the point of withdrawal of extract E and a point of injection of the charge F including lithium; - a lithium adsorption zone III located between the injection point of charge F and a withdrawal point of raffinate R; and - a zone IV is located between the point of withdrawal of the raffinate R and the point of injection of the desorbent D;
[0048] With reference to [Fig.1], 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).
[0049] With reference to [Fig.2], according to one or more embodiments, the feeding and withdrawal points of at least one column Q are shifted over time by a value corresponding to an adsorbent bed A;.
[0050] 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.
[0051] 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 feed and the extract is achievable by the process according to the invention, whereas conventional processes are limited to 3 or 4. The counter-current produced by the process according to the invention provides an advantageous accumulation zone for concentrating the lithium in the extract.
[0052] According to one or more embodiments, the at least one column C comprises a plurality of interconnected columns or adsorbers in a closed loop. According to one or more embodiments, the supply and withdrawal points of the columns C or adsorbers are offset over time by a value corresponding to one column or one adsorber. According to one or more embodiments, the plurality of columns C 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, e.g., between 12 and 15 columns or adsorbers.
[0053] According to one or more embodiments, the adsorbent solid is distributed in zones I to IV according to configurations of type a / b / c / d, 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 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, a process in which: -a = 43%±9%, preferably ± 6%, most preferably ± 3%; - b = 29% ± 6%, preferably ± 4%, most preferably ± 2%; - c = 14% ± 3%, preferably ± 2%, most preferably ± 1%; and - d = 14% ± 3%, preferably ± 2%, most preferably ± 1%.
[0054] According to one or more embodiments, the at least one column C comprises a plurality of beds of solid adsorbent A interconnected in a closed loop and separated by trays P, the feed and withdrawal points in the trays P of the column C being offset over time by a value corresponding to one bed of adsorbent. According to one or more embodiments, the at least one column C comprises between 4 and 24 beds of solid adsorbent A, preferably between 8 and 21 beds of solid adsorbent A.
[0055] According to one or more embodiments, the beds of solid adsorbent A; are distributed in zones I to IV according to configurations of type a / b / c / d, that is to say that the distribution of the beds of solid adsorbent A; is as follows: - a is the number of beds in zone I; - b is the number of beds in zone II; - This is the number of beds in zone III; and - d is the number of beds in zone IV, a process in which: - a = (t * 0.43) * (1 ± 0.20, preferably 1 ± 0.10, very preferably 1 ± 0.05); - b = (t * 0.29) * (1 ± 0.20, preferably 1 ± 0.10, very preferably 1 ± 0.05); - c = (t * 0.14) * (1 ± 0.20, preferably 1 ± 0.10, most preferably 1 ± 0.05); and - d = (t * 0.14) * (1 ± 0.20, preferably 1 ± 0.10, very preferably 1 ± 0.05), process in which t is a natural integer between 4 and 24, preferably between 8 and 21, such that between 12 and 15.
[0056] According to one or more embodiments, the temperature is set so that the temperature in the adsorbent solid remains between 0°C and 120°C and preferably between 5°C and 100°C, particularly preferably between 15°C and 80°C, most preferably between 40°C and 80°C, in particular to promote accelerated perforation of the adsorbent solid.
[0057] Advantageously, 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.
[0058] According to one or more embodiments, a portion of 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, most preferably substantially in the middle of zone II, in particular to improve the concentration of the extract. In this application, the term "substantially in the middle of zone II" refers to zone II. Zone II, comprising a quantity X of adsorbent solid, corresponds to a position located between 0.35*X and 0.65*X of adsorbent solid, preferably between 0.40*X and 0.60*X of adsorbent solid, and most preferably between 0.45*X and 0.55*X of adsorbent solid.
[0059] According to one or more embodiments, at least 1% of extract E or a stream obtained by concentration and / or purification of said extract, preferably at least 5% of extract E or a stream obtained by concentration and / or purification of said extract, and most preferably at least 10% of 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 extract E or a stream obtained by concentration and / or purification of said extract is fed into zone II.
[0060] According to one or more embodiments, the cycle duration is at least 20 min, preferably at least 40 min, such as being 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 feeds / extractions) multiplied by the total number of injection / withdrawal points, such as the total number of columns C used (see example in [Fig. 1]) or of beds of adsorbent solid A used (see example in [Fig. 2]).
[0061] 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 charging flow rate) is between 2 and 12, preferably between 3 and 9, very preferably between 5 and 8.
[0062] 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 0.5, preferably less than 0.2, most preferably less than 0.1. According to one or more embodiments, the volumetric flow rate ratio of the desorbent to the volumetric flow rate of the charge is between 0.01 and 1.0, preferably between 0.02 and 0.5, most preferably between 0.06 and 0.1.
[0063] According to one or more embodiments, the process according to the invention advantageously comprises an activation step of the adsorbent solid. This activation step activates the sites intended to selectively adsorb lithium. Preferably, this activation step is advantageously carried out by passing an activation solution selected from water and a lithium salt solution having a concentration between 0.001 mol / L and 0.1 mol / L, preferably between 0.001 mol / L and 0.05 mol / L, and most preferably between 0.01 and 0.04 mol / L. Preferably, the lithium salt used in solution in this activation step is selected from lithium chloride (LiCl), lithium nitrate, and lithium bromide. Most preferably, the lithium salt used in solution in this activation step is lithium chloride (LiCl). According to one or more embodiments, this activation step is carried out at a temperature between 0°C and 90°C, and preferably between 10°C and 60°C, and 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.
[0064] The simulated moving bed lithium adsorption extraction device comprises the following elements: - at least one column (Ci) adapted to be fed with at least one charge comprising lithium and a desorbent, and to be withdrawn of at least one extract and at least one raffinate from the column (Ci), the at least one column (Ci) comprising an adsorbent solid comprising at least one lithia aluminum oxyhydroxide Al(OH)3 and / or at least one lithia aluminum hydroxide Al(OH)3, the at least one column (Ci) being interconnected in a closed loop, the feed 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 the plurality of zones I, II, III and IV as defined above.
[0065] According to one or more embodiments, the supply and withdrawal points of at least one column (Ci) are offset synchronously.
[0066] 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 quantity of adsorbent solid contained in each of the zones I, II, III, and IV as defined above is then calculated as the average quantity of adsorbent solid contained in each zone over the cycle time. Similarly, the number of beds in each of the zones I, II, III, and IV 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.
[0067] 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.
[0068] 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.
[0069] Said charge may be any natural saline solution, concentrated or obtained from a lithium extraction or transformation process. For example, said solution The saline used in the extraction process according to the invention can advantageously be chosen from brines from salt lakes or geothermal sources, 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.
[0070] According to one or more embodiments, the charge comprises at least 0.1 g / L by 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.
[0071] According to one or more embodiments, the desorbent is selected from the group consisting of water, lithium water, brine, preferably water. According to 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. According to one or more embodiments, the desorbent comprises less than 0.05 g / L of lithium, preferably less than 0.01 g / L of lithium, relative to the total weight of the desorbent.
[0072] According to one or more embodiments, the at least one lithiased aluminum oxyhydroxide A10(OH) comprises lithiased boehmite. According to one or more embodiments, the at least one lithiased aluminum oxyhydroxide A1O(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 A1O(OH). According to one or more embodiments, the at least one lithiased aluminum oxyhydroxide A1O(OH) consists of lithiased boehmite.
[0073] According to one or more embodiments, the at least one lithiased aluminum hydroxide A1(OH)3 comprises lithiased bayerite. According to one or more embodiments, 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.
[0074] 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, 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, most preferably at least 1.5% by weight, relative to the total weight of the adsorbent solid. preferably between 1.5% by weight and 3% by weight, relative to the total weight of the solid adsorbent.
[0075] 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.
[0076] 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.
[0077] 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 shape, 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 and 1.5 mm, preferably between 0.1 and 1 mm, and 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, and more preferably between 0.25 and 1.8 mm.
[0078] The solid adsorbent material is characterized according to the following techniques: nitrogen adsorption for the determination of the specific surface area according to the BET method (e.g., ASTM D 3663-7); 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 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
[0079] Example 1 (according to the invention): Separation of a brine with simulated counter-current.
[0080] 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 of lithium element; - 110 g / L as chlorine; - 70 g / L as elemental sodium.
[0081] The solid adsorbent considered for the separation is a lithia-treated bayerite.
[0082] The process uses a column Ci comprising 21 beds of solid adsorbent A; distributed as follows: - 9 beds in zone 1; - 6 beds in zone 2; - 3 beds in zone 3; - 3 beds in zone 4.
[0083] The separation takes place at 20 °C. The desorbent is water containing no lithium. The desorbent / feed 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.
[0084] The process performance is calculated by simulation. Thermodynamic and mass transfer data were previously obtained by drilling tests, as commonly practiced by those skilled in the art. The concentration profile calculated along the simulated moving bed is shown in [Fig. 3].
[0085] The results indicate an extract concentration of 4.4 g / L, or a concentration factor of 11. This high concentration greatly reduces the equipment and energy consumption required for water evaporation in the downstream stages of the process.
[0086] 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%.
[0087] Example 2 (not in accordance with the invention): Separation of a brine without simulated counter-current
[0088] 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 put in place is operated in batch mode and without the implementation of a simulated counter-current.
[0089] The final product has a final concentration of 1.2 g / L of lithium. The concentration factor obtained is 3 and is significantly lower than the case with simulated counter-current.
[0090] The process according to the invention allows the production of a much more concentrated flow than with a standard batch adsorption process.
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 extract (E) and at least one raffinate (R) are withdrawn from the column (Ci), the at least one column (Ci) comprising an adsorbent solid comprising at least one lithium-containing aluminum oxyhydroxide Al10(OH) and / or at least one lithium-containing aluminum hydroxide Al(OH)3, the at least one column (Ci) being interconnected in a closed loop, the feed 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 located between a desorbent injection point and an extract withdrawal point; - a lithium alkali metal desorption zone II located between the extract withdrawal point and a feed injection point containing lithium; - a lithium adsorption zone III located between the feed injection point and a raffinate withdrawal point; and - a zone IV located between the raffinate withdrawal point and the desorbent injection point.
2. A method according to claim 1, wherein at least one column (Ci) comprises a plurality of columns (Ci) or adsorbers interconnected in a closed loop, the supply and withdrawal points of the columns (Ci) or adsorbers being offset over time by a value corresponding to one column (Ci) or one adsorber.
3. A method according to claim 1 or claim 2, wherein at least one column (Ci) comprises at least 4 columns or adsorbers.
4. A method according to any one of the preceding claims, wherein the adsorbent solid is distributed in zones I to IV according to configurations of type a / b / c / d, 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 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%.
5. Method according to claim 1, the at least one column (Ci) comprises a plurality of beds of solid adsorbent (Ai) interconnected in a closed loop and separated by trays (P;), the feeding and withdrawal points in the trays (R) of the column (Ci) being offset over time by a value corresponding to one bed of adsorbent.
6. A method according to claim 5, wherein at least one column (Ci) comprises between 4 and 24 beds of solid adsorbent (A;).
7. A method according to claim 5 or claim 6, wherein the beds of solid adsorbent (Ai) are distributed in zones I to IV according to configurations of type a / b / c / d, i.e. 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, a method wherein: - 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), a process in which t is a natural integer between 4 and 24.
8. A method according to any one of the preceding claims, wherein a portion of the extract (E) or a stream obtained by concentration and / or purification of said extract (E) is fed into zone II.
9. A method according to any one of the preceding claims, wherein the adsorbent solid comprises lithium bayerite and / or lithium boehmite.
10. 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, relative to the total wt% of the adsorbent solid.
11. A method according to any one of the preceding claims, wherein the adsorbent solid comprises 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.
12. A method according to any one of the preceding claims, wherein the charge (F) comprises at least 0.1 g / L weight of lithium element, relative to the total weight of the charge.
13. A process according to any one of the preceding claims, wherein the steps of the process are carried out at a temperature between 0°C and 120°C.
14. A method according to any one of the preceding claims, wherein the ratio of the volumetric flow rate of the desorbent (D) to the volumetric flow rate of the charge (F) is less than 1.
15. A simulated moving-bed lithium adsorption extraction device comprising the following: - at least one column (Ci) adapted to be fed with at least one charge (F) comprising lithium and a desorbent (D), and to be withdrawn of at least one extract (E) and at least one raffinate (R) from the column (Ci), the at least one column (Ci) comprising an adsorbent solid comprising at least one lithium-containing aluminum oxyhydroxide Al(OH)3 and / or at least one lithium-containing aluminum hydroxide Al(OH)3, the at least one column (Ci) being interconnected in a closed loop, the feed and withdrawal points of the at least one column (Ci) 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 column (Ci), and in particular the following main areas designated by definition by a number: - a lithium desorption zone I located between a desorbent injection point and an extract withdrawal point; - a zone II for the desorption of alkali metals other than lithium and / or alkaline earth metals located between the point of withdrawal of the extract and a point of injection of the charge including lithium; - a lithium adsorption zone III between the charge injection point and a raffinate withdrawal point; and - a zone IV between the raffinate withdrawal point and the desorbent injection point.