Lithium isotope separation

Abstract

The present disclosure relates to a method for isotope separation of lithium, comprising the steps of providing a first mixture (104) comprising at least lithium, lithium hydride, and optionally lithium deuteride and / or lithium tritide and at a first temperature, a first cooling step (110), preferably a uniform cooling step, adapted to cool the first mixture to a second temperature lower than the first temperature, the first cooling step adapted to precipitate a first portion of lithium hydride having a first lithium isotope, and a first separation step (124) adapted to separate the precipitated first portion of lithium hydride from the first mixture to form a second mixture (122).

Description

[Technical field]

[0001] Disclosed herein is a method for isotope separation of lithium. In particular, the disclosed method is directed to the separation of lithium isotopes in a fluid medium based on differences in phase transition temperatures. [Background technology]

[0002] There is a worldwide need for isotope separation, primarily the separation of lighter isotopes from elements. For nuclear applications, including fusion and fission, the naturally occurring isotope of lithium, lithium-6( 6 Li) and lithium-7( 7 Naturally occurring lithium is 7.4% 6 Li and 92.6% 7 Contains Li.

[0003] In nuclear fusion for nuclear power generation, lithium is used to breed tritium, the primary fuel in fusion generators. However, the most commonly occurring isotope of lithium is tritium. 7 Li has poor tritium breeding due to its small cross section, and is therefore not suitable for use as a tritium breeding blanket. 6 It is desirable to use Li. This isotope is less common, so enrichment of lithium is required. 6 The concentration of Li is increased. In solid-state growth, the concentration may have to be increased to 30%-60%, whereas in liquid-state growth, the concentration may have to be increased to as high as 90%.

[0004] Enriched lithium is useful in other applications. In nuclear fission power generators, for control of acidity, neutron moderation, as a neutron absorber, and as a coolant in molten salt reactors, it is used in about 99% pure form. 7 Li is used.

[0005] Li-ion batteries are 6The current demand for enriched lithium is increasing as nuclear fusion reactors become more efficient, and is expected to increase further in the coming years as fusion reactors become a reality.

[0006] Currently, enriched lithium is supplied by stockpiles produced in the United States in the 1950s and 1970s using an expensive process known as COLEX. 6 The market price for Li is about $500 per 10 grams, a cost prohibitive considering that the quantities needed for a gigawatt-energy fusion power plant are on the order of 60 tonnes.

[0007] Currently, there appear to be no methods that could potentially produce the amounts of enriched lithium needed for a fusion power plant, and those that have been developed suffer from two problems: they are very expensive and highly polluting to the environment.

[0008] Enriched lithium has been produced mainly by three methods: COLEX, OREX, and ELEX. COLEX and OREX are chemical exchange processes based on the countercurrent flow of LiOH or LiCl solutions and lithium amalgam. The enriched lithium is deposited in the amalgam phase. Methods based on the electrical properties of lithium have also been used. In the ELEX process, a lithium salt solution is electrolyzed in a countercurrent flow with a mercury cathode.

[0009] Notably, the above mentioned processes utilize mercury to some extent. In the 1950s-1980s, these processes were widely used to produce lithium in the United States. The COLEX process alone used approximately 24 million pounds of mercury. While most of that mercury was properly delivered, approximately 2 million pounds are unaccounted for. This unaccounted for mercury may have been lost to the environment and may be a source of mercury contamination in some water bodies in East Virginia.

[0010] Current trends in the separation or enrichment of lithium ions include laser and electromagnetic separation. These methods are expensive and slow, and they also require very specialized materials and equipment. The limitations of these methods have been highlighted by Dr. Inge Thomas Giegerich, lead engineer for the development of the DEMO vacuum system. In his paper "Lithium Enrichment Issues in a Sustainable Supply Chain for Future Fusion Reactors," available at www.kit.edu, Dr. Inge Thomas Giegerich writes that since the traditional COLEX-related methods have the highest quality values ​​with the least development effort, it is proposed to further develop the mercury-based methods.

[0011] In U.S. Patent No. 8,672,138 by Reisen et al., a vapor with several atoms of a single element is formed into a stream and then a light wave is applied. The light wave is adjusted to prepare a particular isotope in a particular magnetic state. A magnetic field is then applied that separates the isotopes according to their magnetic state. The methods described are explicitly based on both laser and electromagnetic methods that exploit these properties of isotopes. Methods such as the method described by Reisen are inappropriate for lithium applications. They are inadequate because the lithium isotopes in the fusion reactor must be separated as part of the power plant process. Since the elements must be vaporized, this method is not easily integrated with the fusion reactor process where the lithium can be either liquid or solid. The main problem with Reisen's method is that the temperatures at which the fusion process works may not allow all parts of the method to work. In addition, the method may be too slow to accommodate the speeds required by a fusion reactor. Also, the light wave equipment required by this method may require very specialized temperatures and expensive components to function, making it less suitable for fusion power plants that rely on lithium enrichment.

[0012] Another method based on lasers is described in US Patent No. 4,149,077 by Yamashita et al. The Yamashita laser separates lithium isotopes by irradiating a lithium atomic beam with a beam tuned to the absorption line of one of the isotopes of lithium. This ionizes the isotopes, which are then separated by a mass filter, for example a magnetic field-based mass spectrometer. This method has the problem that the lithium needs to be in a very specific state, in this case a lithium atomic beam, in order for it to function. Using this method in a fusion power plant requires that the functioning lithium be removed from the process, processed, and then reinserted. This can cause additional heat losses, which may not be easy to overcome depending on the plant configuration. Furthermore, this method is not a method that would function properly as part of a fusion power plant process, since the processes may need to be stopped to prepare the lithium and then effect the separation. Summary of the Invention [Problem to be solved by the invention]

[0013] Processes based on the electromagnetic properties of isotopes and laser methods are also surface or volume effects on atomic or ion beams, and are necessarily in a gaseous or plasma state, which is typically less dense than a liquid or solid, making them very difficult and expensive to scale. These processes are also very energy inefficient, in addition to the overall cost of the process. Considering that experts in the field point out that current trends are limited to chemical separation methods using mercury, such as COLEX, and methods that utilize the electromagnetic properties of lithium isotopes, there is a need for a lithium isotope separation method that is reliable, cheap, fast, environmentally friendly, and can work in conjunction with the fusion reactor process. [Means for solving the problem]

[0014] One embodiment addresses all or some of the shortcomings of known methods for isotope separation of lithium.

[0015] One embodiment provides a method for isotope separation of lithium, the method comprising: providing a first mixture comprising at least lithium, lithium hydride, and optionally lithium deuteride and / or lithium tritide, the first mixture being at a first temperature; a first cooling step, preferably a uniform cooling step, adapted to cool the first mixture to a second temperature lower than the first temperature, the first cooling step adapted to precipitate a first portion of lithium hydride having a first lithium isotope; a first separation step adapted to separate a first portion of the precipitated lithium hydride from the first mixture to form a second mixture.

[0016] In one embodiment, the method further comprises a first extraction step adapted to extract a first portion of the precipitated lithium hydride after or during the first separation step.

[0017] In one embodiment, the method comprises: a second cooling step, preferably a uniform cooling step, adapted to cool the second mixture to a third temperature lower than the second temperature, the second cooling step adapted to precipitate a second portion of the lithium hydride having a second lithium isotope; and a second separation step adapted to separate a second portion of the precipitated lithium hydride from the second mixture to form a third mixture.

[0018] In one embodiment, the method further comprises a second extraction step adapted to extract a second portion of the precipitated lithium hydride after or during the second separation step.

[0019] In one embodiment, the first and / or second cooling steps are slow, for example having a cooling rate of less than 1° C. per minute.

[0020] In one embodiment, providing the first mixture comprises a heating step adapted to heat the first mixture to a first temperature.

[0021] In one embodiment, the method includes repeating the providing step; a first cooling step and a first separation step, in which at least a portion of the second mixture is used as the first mixture; and / or a second cooling step and a second separation step, in which at least a portion of the third mixture is used as the first mixture; Repeat the process of Includes.

[0022] In one embodiment, the first isotope is 7 Li isotope, and the second isotope is 6 It is a Li isotope.

[0023] In one embodiment, The first temperature is greater than about 410° C., for example greater than about 500° C. the second temperature is between 390°C and 410°C, for example equal to about 400°C; and / or The third temperature is between 388°C and 408°C, for example equal to about 398°C.

[0024] In one embodiment, at least one of the first and second separation steps comprises rotating the first and / or second mixture, e.g. rotating a chamber containing said mixture.

[0025] One embodiment provides a method for isotope separation of lithium, the method comprising: providing a first mixture comprising at least lithium and lithium hydride and at a first temperature; a first cooling step, preferably a uniform cooling step, adapted to cool the first mixture to a second temperature lower than the first temperature, the first cooling step adapted to precipitate a first portion of lithium hydride having a first lithium isotope; a first separation step adapted to separate a first portion of the precipitated lithium hydride from the first mixture to form a second mixture; a first extraction step adapted to extract a first portion of the separated lithium hydride after or during the first separation step.

[0026] In one embodiment, the first mixture further comprises lithium deuteride and / or lithium tritide.

[0027] In one embodiment, the first cooling step is slow, for example having a cooling rate of less than 1° C. per minute.

[0028] In one embodiment, the method comprises: a second cooling step, preferably a uniform cooling step, adapted to cool the second mixture to a third temperature lower than the second temperature, the second cooling step adapted to precipitate a second portion of the lithium hydride having a second lithium isotope; a second separation step adapted to separate a second portion of the precipitated lithium hydride from the second mixture to form a third mixture; and a second extraction step adapted to extract a second portion of the separated lithium hydride after or during the second separation step.

[0029] In one embodiment, the second cooling step is slow, for example having a cooling rate of less than 1° C. per minute.

[0030] In one embodiment, providing the first mixture comprises a heating step adapted to heat the first mixture to a first temperature.

[0031] In one embodiment, the method includes repeating the providing step; a first cooling step and a first separation step, in which at least a portion of the second mixture is used as the first mixture; and / or and repeating the second cooling step and the second separating step, where at least a portion of the third mixture is used as the first mixture.

[0032] In one embodiment, the method includes repeating the providing step; a first cooling step, a first separation step and a first extraction step, in which at least a portion of the second mixture is used as the first mixture; and / or and repeating the second cooling step, the second separation step, and the second extraction step, where at least a portion of the third mixture is used as the first mixture.

[0033] In one embodiment, the first isotope is 7 Li isotope, and the second isotope is 6 It is a Li isotope.

[0034] In one embodiment, The first temperature is greater than about 410° C., for example greater than about 500° C. the second temperature is less than or equal to 410° C., for example between 390° C. and 410° C., for example equal to about 400° C.; and / or The third temperature is less than or equal to 408°C, for example between 388°C and 408°C, for example equal to about 398°C.

[0035] In one embodiment, at least one of the first and second separation steps comprises rotating the first and / or second mixture, e.g. rotating a chamber containing said first and / or second mixture.

[0036] In one embodiment, the first and second temperatures are determined according to the concentration of lithium hydride in the first mixture.

[0037] In one embodiment, the third temperature is determined according to the concentration of lithium hydride in the first mixture.

[0038] In one embodiment, the first and second temperatures are determined using a Li / LiH phase diagram.

[0039] In one embodiment, the third temperature is determined using a Li / LiH phase diagram.

[0040] In one embodiment, the molar concentration of lithium hydride in the first mixture is between 2 and 95%, including, for example, between 2.5% and 95%.

[0041] In one embodiment, each of the second and third temperatures is greater than 200°C, such as greater than 210°C.

[0042] In one embodiment, there is provided an apparatus adapted to perform a method according to an embodiment, the apparatus comprising: a chamber adapted to contain a mixture comprising at least lithium and lithium hydride; a cooling mechanism adapted to cool the mixture within the chamber; Includes.

[0043] In one embodiment, the cooling mechanism includes a cooling jacket at least partially covering the chamber and means adapted to transport a coolant within the cooling jacket.

[0044] In one embodiment, the apparatus further includes a heater, such as an ohmic heater or an inductive heater, adapted to heat the mixture in the chamber.

[0045] In one embodiment, the apparatus further comprises a rotating means adapted to rotate the chamber, for example a shaft coupled to the chamber and a motor disposed outside the chamber.

[0046] In one embodiment, the chamber is shaped to allow for drainage of liquid or solid contents that accumulate at the bottom of the chamber, for example, a bell shape, an inverted bell shape, or a diamond shape. [Brief description of the drawings]

[0047] The above and other features and advantages are explained in detail in the following description of specific embodiments, shown by way of example and not by way of limitation in reference to the accompanying drawings.

[0048] [Figure 1] FIG. 1 shows a diagram for explaining a method for separating lithium isotopes. [Diagram 2] 1 shows a front view of an apparatus for carrying out a method for isotope separation of lithium. [Diagram 3] The Li / LiH phase diagram is shown as a function of LiH molar concentration. [Figure 4] Another Li / LiH phase diagram is shown as a function of LiH molar concentration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Similar features are indicated by similar reference numbers in the various figures, and in particular, structural and / or functional features that are common among the various embodiments may bear the same reference numbers and may exhibit identical structural, dimensional and material characteristics.

[0050] For purposes of clarity, only those operations and elements that are useful for understanding the embodiments described herein have been shown and described in detail.

[0051] Unless otherwise indicated, when referring to two elements connected to each other, this means a direct connection with no intermediate elements other than conductors, and when referring to two elements bonded together, this means that the two elements may be connected or the two elements may be bonded via one or more other elements.

[0052] In the following disclosure, unless otherwise indicated, when referring to absolute positional qualifiers such as "front", "back", "top", "bottom", "left" or "right", relative positional qualifiers such as "above", "below", "higher" or "lower", or directional qualifiers such as "horizontal" or "vertical", reference is made to the orientation shown in the drawings.

[0053] Unless otherwise specified, the terms "about," "approximately," "substantially," and "on the order of" mean within 10%, preferably within 5%.

[0054] The drawings are not to scale. It should be noted that the drawings show one embodiment of the disclosed method and apparatus for isotope separation of lithium, which may be simply described as an apparatus or method, respectively. Other embodiments may be possible, as one of ordinary skill in the art can readily appreciate. The actual dimensions and / or shapes of each component of the embodiment may vary. Only the essential details of the embodiment are shown, but one of ordinary skill in the art can appreciate how the entire apparatus may be constructed without undue experimentation. Similarly, one of ordinary skill in the art may expect that the steps of the method may be performed in a different order according to the particular needs of the use. Although some details have been omitted from the drawings, the inventors believe that adding these details is not necessary for a complete understanding of the disclosed features of the invention. These omitted details include, among others, elements for holding or securing the apparatus or its functional components. Some features of the embodiments are exaggerated for ease of understanding. The disclosed embodiments and the alternatives envisaged should not be considered as limiting the invention in any manner.

[0055] A diagram of one embodiment of a method for isotope separation of lithium is shown in FIG.

[0056] In this embodiment, the Li / LiH mixture 104 (first mixture) undergoes a heating step 106. After being heated, the Li / LiH mixture 104 is at a first temperature, for example, greater than about 500° C., in a mixture above 500° C. step 108. Thereafter, there is a first slow uniform cooling step 110. The Li / LiH mixture 104 is then cooled until it reaches a second temperature, for example, about 400° C., in a mixture at about 400° C. step 112. This step converts the first lithium isotope into a hydrogen compound. 7 LiH precipitates as part of this process. 7This may be referred to as LiH precipitation step 114. At this point, the process may split into two branches. In the first branch, 7 In a LiH separation step 124, LiH is separated from the remainder of the Li / LiH mixture 104. 7 LiH is separated. The remaining Li / LiH mixture 104( 7 LiH) is 7 It may be referred to as a second Li / LiH mixture 122 that is devoid of LiH. 7 LiH is then clearly separated and 7 The second branch involves cooling the second Li / LiH mixture 122 in a second slow uniform cooling step 116. The second Li / LiH mixture 122 is cooled in a mixture at about 398° C. step 118 until a third temperature in the mixture is reached, for example, about 398° C. At this temperature, hydrogen compounds 6 Precipitation of other lithium isotopes begins as part of LiH. This stage is 6 This step is referred to as LiH precipitation step 120. Again, at this stage, two different branches can follow. In the first branch, the isotope 6 The isotopes are then separated in LiH separation step 130. 6 The LiH can be extracted in the LiH extraction step 136. The second branch is reforming the Li / LiH mixture 104 and the process can be started again, or 6 The formation of a third Li / LiH mixture obtained in the second branch after the LiH precipitation step 120 may serve as the first mixture in a repeat of the process.

[0057] or, 7 After the LiH precipitation step 114 and after obtaining the second Li / LiH mixture 122, the process can be restarted, but without a second cooling step. 6 The branch that performs the LiH precipitation step 120 is not followed.

[0058] Uniform cooling (or uniformly cooling) refers to cooling that is substantially uniform throughout the entire volume of the mixture, and slow cooling refers to a cooling rate of, for example, less than 1° C. per minute.

[0059] The temperatures shown in the diagram of FIG. 1 are representative temperatures and may depend on the concentration of lithium hydride in the mixture.

[0060] An embodiment of an apparatus capable of replicating the method of FIG. 1 is shown in FIG. 2. The apparatus of FIG. 2 includes a chamber 214 with an inlet at the top and an outlet at the bottom. The apparatus includes a heating means, which may be described as a coil 202 for ohmic heating, but may also be another type of heating mechanism, such as an induction heating coil. To center the apparatus, a centering magnet 206 may be placed near the top of the apparatus. The apparatus may also be raised and lowered, for which purpose a lifting magnet 210 may also be formed. The motor 212 may be coupled, for example, to a shaft 208. The shaft 208 may be coupled, for example connected, to the chamber 214 so as to rotate the chamber 214. The apparatus may be covered by a cooling jacket 204. The cooling jacket 204 may include a means for transporting a coolant so as to cool the interior of the chamber 214.

[0061] Example of operation The method described in Figure 1 can be adapted to work with mixtures containing lithium and lithium hydride having different molar compositions according to the phase diagrams of Figures 3 and 4. The horizontal axis of Figures 3 and 4 represents the molar concentration of LiH in the Li / LiH mixture.

[0062] The mixture containing lithium and lithium hydride may also contain lithium deuteride and / or lithium tritide.

[0063] As a meaningful example of the operation of this method, two trajectories are shown in Figure 3. It should be understood that these two trajectories are not limiting and other trajectories with different LiH molar concentrations may also be used. A person skilled in the art should be able to determine the best molar composition according to the needs of a particular use of this method.

[0064] 1 in an alpha liquid phase α(l) at a molar composition of about 5% LiH and a temperature of about 500° C. or greater. When cooled below about 500° C., the Li / LiH mixture 104 separates into a liquid alpha phase α(l) and a solid beta phase β(s).

[0065] The second trajectory 306 may begin with a Li / LiH mixture 104 at a molar composition of about 85% LiH and a temperature above about 900° C. Upon cooling, the Li / LiH mixture 104 separates into two distinct liquid phases, an alpha phase and a beta phase α(l)+β(l). Further cooling of the Li / LiH mixture causes the beta phase to solidify into a beta solid phase β(s).

[0066] As can be seen in Fig. 4, in the alpha liquid phase and the beta solid phase α(l) + β(s), the alpha phase α(l) is Li( 6 Li, 7 Li) concentration is high, 6 Above the precipitation temperature of LiH, the cooling process is particularly uniform and 6 Without reaching the LiH precipitation temperature, 7 If stopped at the LiH precipitation temperature, 6 The LiH concentration can also be high, and the beta solid phase β(s) is LiH-rich, more specifically: 6 Above the precipitation temperature of LiH, the cooling process is particularly uniform and 6 Without reaching the LiH precipitation temperature, 7 If stopped at the LiH precipitation temperature, 7 The LiH concentration can be high.

[0067] Therefore, with the transition temperature depending on the LiH molar concentration, 6 LiH isotopes and 7 It is possible to separate the LiH isotopes. Depending on the LiH molar concentration, 6 The precipitation temperature of LiH is 7 The precipitation temperature of LiH may differ by several degrees. 6 The precipitation temperature of LiH is 7 It may be lower than the precipitation temperature of LiH. For example, 7 The precipitation temperature of LiH is6 The difference from the LiH precipitation temperature can be 1-5°C, or 2-4°C, which is sufficient to perform isotope separation.

[0068] It is well known in chemistry that molecules undergo the "isotope effect", i.e. slight differences in behavior, depending on the specific isotope used for each atom. This is a universal effect that can be explained by the fact that atoms of different isotopes interact with each other with almost identical forces, but have different masses. By this effect it is possible to explain that the phase diagram of the Li / LiH system changes according to the specific H isotope, which can be H, D (deuterium) or T (tritium). That is, as described, for example, on pages 136-140 of "Applied Chemistry of Alkali Metals" by Hans U. Borgostedt and Cherian K. Matthews, the transition temperatures from one phase to another, or from one phase to two different phases, differ slightly, for example by a few degrees, depending on the H isotope in the Li / LiH system.

[0069] Furthermore, due to the different isotopic masses, the phase diagram of the Li / LiH system is expected to vary according to the specific Li isotope, and slightly different transition temperatures are expected depending on the Li isotope in the Li / LiH system. As shown in Figure 4, 6 Li and 7 Since the mass difference with Li is the same as the mass difference between H and D (one neutron), these temperature differences are expected to be of the same order of magnitude as the H isotope in the Li / LiH system, e.g., a few degrees.

[0070] Therefore, the isotopes 6 LiH and 7 These differences between LiH and 6 Li / 7 Li / 6 LiH / 7 From LiH solution, 6 LiH or 7 Allows for selective precipitation of LiH.

[0071] 3 and 4 further show that transition temperatures adapted to effect separation between isotopes of LiH for any LiH molar concentration in a Li / LiH mixture, e.g., 2% to 95% molar concentration, can be determined using a Li / LiH phase diagram, e.g., the Li / LiH phase diagram of FIG. 3 or FIG. 4.

[0072] A first embodiment of an apparatus 200 for isotope separation of lithium shown in FIG. 2 may perform the steps of the method of FIG. 1 as follows: Li / LiH mixture 104 is deposited into the apparatus chamber 214 from an inlet at the top of the apparatus. The Li / LiH mixture 104 may then be heated through a heating coil 202. Once the Li / LiH mixture 104 is in the mixture step 108 above about 500° C., a cooling jacket 204 may be used to cool the Li / LiH mixture 104 during a first slow uniform cooling step 110 or a second slow uniform cooling step 116. For isotope separation, the chamber 214 may rotate. The chamber 214 is coupled to a motor 212 by a shaft 208 so that the chamber 214 rotates when the motor 212 operates. The rotation of the chamber 214 may be used to separate the Li / LiH mixture 104 into its constituent phases, alpha and beta, using effects such as density difference. That is, for example, 7 LiH and / or 6 The beta phase, which is more concentrated in LiH, is denser and therefore accumulates at the outer diameter when subjected to centrifugal force. This embodiment of the device is shaped in a way that allows the liquid or solid contents of chamber 214 that accumulate at the bottom to be drained. This function of the shape may be accomplished through other means or through a different shape. For example, in another embodiment, the shape may be described as a bell shape, an inverted bell shape, a diamond shape, or any other shape that allows for the accumulation of solid or liquid material at the bottom.

[0073] Other apparatus may be used to carry out the steps of the method according to the embodiments. Another example of an apparatus is shown in European Patent Application No. 22305438, entitled "Apparatus and Method for Extraction of Lithium Hydride" and filed by the same applicant "Renaissance Fusion" on April 4, 2022, the disclosure of which is incorporated herein by reference to the fullest extent permitted by law. In addition, at least some of the methods, or steps of the methods, described in the above application may be used to separate lithium from lithium hydride after lithium isotope separation.

[0074] Illustrative embodiments of the present invention are summarized here. Other embodiments can be understood from the entire specification, as well as the claims set forth herein.

[0075] Example 1. 1. A method for isotope separation of lithium comprising the steps of: providing a first mixture (104) comprising at least lithium, lithium hydride, and optionally lithium deuterium and / or lithium tritide, the first mixture being at a first temperature; a first cooling step (110), preferably a uniform cooling step, adapted to cool the first mixture to a second temperature lower than the first temperature, the first cooling step adapted to precipitate a first portion of lithium hydride having a first lithium isotope; a first separation step (124) adapted to separate a first portion of the precipitated lithium hydride from the first mixture to form a second mixture (122); A method comprising:

[0076] Example 2. 2. The method of claim 1, further comprising a first extraction step (134) adapted to extract a first portion of the precipitated lithium hydride after or during the first separation step (124).

[0077] Example 3. a second cooling step (116), preferably a uniform cooling step, adapted to cool the second mixture (122) to a third temperature lower than the second temperature, the second cooling step adapted to precipitate a second portion of the lithium hydride having a second lithium isotope; a second separation step (130) adapted to separate a second portion of the precipitated lithium hydride from the second mixture to form a third mixture; The method of Example 1 or 2, further comprising:

[0078] Example 4. 4. The method of example 3, further comprising a second extraction step (136) adapted to extract a second portion of the precipitated lithium hydride after or during the second separation step (130).

[0079] Example 5. The method according to any one of Examples 1 to 4, wherein the first and / or second cooling step is slow, for example having a cooling rate of less than 1° C. per minute.

[0080] Example 6. The method of any one of Examples 1 to 5, wherein the step of providing the first mixture (104) comprises a heating step (106) adapted to heat the first mixture to a first temperature.

[0081] Example 7. Repeating the providing step; a first cooling step and a first separation step, in which at least a portion of the second mixture is used as the first mixture; and / or a second cooling step and a second separation step, in which at least a portion of the third mixture is used as the first mixture; Repeating the steps of: The method according to any one of Examples 1 to 6, comprising:

[0082] Example 8. The first isotope 7 Li isotope, and the second isotope 6The method according to any one of Examples 1 to 7, wherein the Li isotope.

[0083] Example 9. the first temperature is greater than about 410° C., e.g., greater than about 500° C.; the second temperature is between 390°C and 410°C, for example equal to about 400°C; and / or The method according to any one of the preceding embodiments, wherein the third temperature is between 388°C and 408°C, for example equal to about 398°C.

[0084] Example 10. The method of any one of Examples 1 to 9, wherein at least one of the first and second separation steps comprises rotating the first and / or second mixture, such as rotating a chamber (214) containing the mixture.

[0085] Example 11. An apparatus (200) adapted to carry out the method according to any one of Examples 1 to 10, comprising: a chamber (214) adapted to contain a mixture (104) comprising at least lithium and lithium hydride; a cooling mechanism adapted to cool the mixture within the chamber; An apparatus comprising:

[0086] Example 12. 12. The apparatus of embodiment 11, wherein the chamber (214) has an inlet at the top and an outlet at the bottom.

[0087] Example 13. 13. The apparatus of embodiment 11 or 12, wherein the cooling mechanism comprises a cooling jacket (204) at least partially covering the chamber, and a means adapted to transport a coolant within the cooling jacket.

[0088] Example 14. The apparatus of any one of Examples 11-13, further comprising a heater (202) adapted to heat the mixture in the chamber, such as an ohmic heater or an inductive heater.

[0089] Example 15. The apparatus of any one of Examples 11 to 14, further comprising a rotating means adapted to rotate the chamber, such as a shaft (208) coupled to the chamber and a motor (212) disposed outside the chamber.

[0090] Example 16. The device of any one of Examples 11 to 15, wherein the chamber (214) is shaped to allow for the discharge of liquid or solid contents that accumulate at the bottom of the chamber, such as a bell shape, an inverted bell shape, or a diamond shape.

[0091] Various embodiments and variations have been described, and those of ordinary skill in the art will recognize that certain features of these embodiments may be combined and other variations will readily occur to those skilled in the art.

[0092] Finally, practical implementation of the embodiments and modifications described herein is within the capabilities of those skilled in the art based on the above functional descriptions.

[0093] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 22305449, filed April 4, 2022, entitled "ISOTOPE SEPARATION OF LITHIUM", and European Patent Application No. 22305438, filed April 4, 2022, entitled "Apparatus and Method for Extraction of Lithium Hydride", the disclosures of which are incorporated by reference herein to the maximum extent permitted by law.

[0094] Acronym Explanation 6 Li: Lithium-6 7 Li: Lithium-7 COLEX: Column exchange OREX: organic exchange ELEX: Electrical exchange LiOH: Lithium hydroxide LiCl: Lithium chloride DEMO: Demonstration fusion power plant LiH: Lithium hydride Li: Lithium 7 LiH: Lithium hydride-7 6 LiH: Lithium-6 hydride

Claims

1. A method for isotope separation of lithium, A step of providing a first mixture containing at least lithium and lithium hydride, at a first temperature, A first cooling step, preferably a uniform cooling step, adapted to cool the first mixture to a second temperature lower than the first temperature, wherein the first cooling step is adapted to precipitate a first portion of the lithium hydride having a first lithium isotope, A first separation step adapted to separate the first portion of the precipitated lithium hydride from the first mixture to form a second mixture, A first extraction step, adapted to extract the first portion of the separated lithium hydride, after or during the first separation step, Methods that include...

2. The method according to claim 1, wherein the first cooling step is slow, for example, having a cooling rate of less than 1°C per minute.

3. A second cooling step, preferably a uniform cooling step, adapted to cool the second mixture to a third temperature lower than the second temperature, wherein the second cooling step is adapted to precipitate the second portion of the lithium hydride having the second lithium isotope, A second separation step adapted to separate the second portion of the precipitated lithium hydride from the second mixture to form a third mixture, A second extraction step, adapted to extract the second portion of the separated lithium hydride, after or during the second separation step, The method according to claim 1, further comprising:

4. The method according to claim 3, wherein the second cooling step is slow, for example, having a cooling rate of less than 1°C per minute.

5. The method according to claim 1, wherein the step of providing the first mixture includes a heating step adapted to heating the first mixture to the first temperature.

6. A process of repeating the above-mentioned process, The first cooling step and the first separation step, and / or, wherein at least a portion of the second mixture is used as the first mixture. The second cooling step and the second separation step, wherein at least a portion of the third mixture is used as the first mixture. The process involves repeating the following steps, The method according to claim 3, including the method described in claim 3.

7. The first lithium isotope is ７ The second lithium isotope is a Li isotope. ６ The method according to claim 3, wherein the Li isotope is used.

8. The first temperature is higher than approximately 410°C, for example, higher than approximately 500°C. The second temperature is 410°C or less, for example, 390°C to 410°C, for example, equal to about 400°C, and / or The method according to claim 3, wherein the third temperature is 408°C or less, for example, 388°C to 408°C, and for example, equal to about 398°C.

9. The method according to claim 1, wherein at least one of the first and second separation steps includes a step of rotating the first and / or second mixture, for example, a step of rotating a chamber containing the first and / or second mixture.

10. The method according to claim 3, wherein the first and second temperatures, and for example the third temperature, are determined according to the concentration of lithium hydride in the first mixture.

11. The method according to claim 3, wherein the first and second temperatures, and for example the third temperature, are determined using a Li / LiH phase diagram.

12. The method according to claim 1, wherein the molar concentration of lithium hydride in the first mixture is 2 to 95%, for example, 2.5% to 95%.

13. The method according to claim 3, wherein each of the second temperature and the third temperature is higher than 200°C, for example, higher than 210°C.

14. An apparatus adapted to carry out the method described in any one of claims 1 to 13, A chamber adapted to contain a mixture comprising at least lithium and lithium hydride, A cooling mechanism adapted to cool the mixture in the chamber, A device including a device.

15. The apparatus according to claim 14, wherein the cooling mechanism includes a cooling jacket that covers at least partially the chamber, and means adapted for transporting a coolant within the cooling jacket.

16. The apparatus according to claim 14, further comprising a heater adapted for heating the mixture in the chamber, for example, an ohm heater or an induction heater.

17. The apparatus according to claim 14, further comprising a rotating means adapted to rotate the chamber, for example, a shaft coupled to the chamber and a motor located outside the chamber.

18. The apparatus according to claim 14, wherein the chamber has a shape that allows for the discharge of liquid or solid contents accumulated at the bottom of the chamber, for example, a bell shape, an inverted bell shape, or a rhombus shape.

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