Lithium hydride extraction device and method

Abstract

The present disclosure relates to a method for separating lithium from a lithium mixture, the method comprising the steps of providing a first mixture (104) comprising at least a first compound of lithium, lithium hydride, and lithium deuterium and lithium tritide and at a first temperature, a first stirring step (108) adapted to stir the first mixture, a first cooling step (110) adapted to cool the first mixture, preferably uniformly, to a second temperature lower than the first temperature, the first stirring step and the first cooling step adapted to deposit at least a portion of the first compounds, and a first separation step (116) adapted to separate at least the deposited first compounds from the first mixture and form a second mixture (118) comprising at least lithium and lithium hydride.

Description

[Technical field]

[0001] The present disclosure relates to an apparatus and method for separating lithium hydrides in liquid mixtures, and in particular to the separation of lithium hydride, lithium deuteride and lithium tritide in mixtures containing lithium. [Background technology]

[0002] Currently, the world is highly dependent on fossil fuels, which has serious consequences for the climate, warming and degradation of the biosphere. The only alternative known to mankind is nuclear power, and the only alternative that can achieve adequate safety and fuel efficiency is fusion power.

[0003] The prospect of fusion power brings with it the problem of tritium breeding. In fact, the most efficient fusion reaction is deuterium-tritium, which requires a 50-50% mixture of deuterium and tritium. Tritium therefore represents half of the most efficient fusion reaction and is also a very rare isotope of hydrogen. To be used as a fuel, tritium must be artificially produced, since it is calculated that there is about 20 kg of naturally occurring tritium. Currently, the price of one gram of tritium is about $30,000.

[0004] Current methods for the production of tritium in fusion reactors involve recovering lithium from a lithium blanket or breeder. As part of the fusion reaction process, neutrons are released, and the lithium then reacts with the neutrons to produce tritium. The lithium blanket can be composed of solid or liquid lithium.

[0005] After the lithium blanket is bombarded with neutrons, the reaction products remain within the blanket. As the products are within the blanket, they need to be extracted. In the case of a liquid blanket, this would pose an additional problem. The neutron bombardment of lithium produces many products, either by initial or subsequent reactions, with the majority of these products being helium and tritium. Furthermore, the environment in which these products are formed favors the subsequent reaction of tritium with lithium. This leads to the formation of lithium tritide, LiT, and in addition to the exposure of lithium to a deuterium-tritium plasma, this can also lead to the formation of lithium deuteride, LiD. These compounds appear along with the pure lithium and other impurities in the liquid blanket, and they must be separated in order to extract the tritium and reuse it. Another compound, lithium hydride, LiH, does not form spontaneously, but can be added to the liquid blanket to facilitate said separation, without exposure to neutrons or to a deuterium-tritium plasma. The following ionic compounds may all be named "lithium hydride": lithium hydride (LiH), lithium deuteride (LiD), and lithium tritide (LiT).

[0006] Currently, the industry faces this problem using methods that have several limitations. The prior art teaches the Maroni process, which uses high temperature molten mixed alkali metal halide salts, i.e. LiCl:LiF:LiBr, as the extraction solvent. This process is known to develop impurities such as liquid and gaseous acids, such as HCl, HF and HBr, in the salt phase, and therefore these solvents are highly corrosive and volatile.

[0007] One of these methods is described in U.S. Patent No. 10,450,600 by Garcia-Diaz et al., where an electrochemical cell is utilized to follow the method of extracting tritium from a molten lithium metal solution. This method has a number of limitations that prevent it from being used in certain applications, for example as part of the operation of a nuclear fusion power plant. The first limitation is that the lithium mixture must be treated with an electrolyte, which requires the composition of the mixture to be modified to add said electrolyte. Thus, an additional step of adding electrolyte to the mixture must be added to the already time-constrained process of an operating power plant. The second limitation of this method relates to the electrochemical cell apparatus. Since the mixture must be deposited on the cell, sufficient time must occur for the electrochemical separation step. In certain applications, it becomes prohibitively expensive to include an electrochemical cell that can hold the mixture at its operating temperature. Furthermore, time considerations may require that the separation step be performed faster, and with the method described with the electrochemical cell described in that document, it is not readily apparent how to increase the separation rate. A final apparent limitation of this system is that it preferably produces tritium gas as one of the separation products. This is a severe limitation because tritium must be converted to another state in order to be used in certain applications, imposing limitations on time requirements.

[0008] Other methods involve different solvents. Such a method is described in International Publication WO2013 / 166505 by Farmer. In this Farmer document, molten lithium compounds including LiOH and Li2CO3 can be used as a solvent to extract lithium tritide from molten lithium metal. In particular, the use of LiOH avoids the production of HF. However, the method described by Farmer also involves electrolyzing the extracted LiT solution in an electrochemical cell and does not overcome this limitation in the prior art. Summary of the Invention [Problem to be solved by the invention]

[0009] Thus, there remains a need for a method to separate lithium from the ionic compounds lithium tritide and, if present, lithium hydride and / or lithium deuteride for application in the emerging nuclear fusion industry. The method does not require significant stages such as solvents or electrochemical cells. A reliable method or apparatus capable of separating these compounds from the mixture would greatly reduce the cost and facilitate efficient energy production from nuclear fusion reactions. [Means for solving the problem]

[0010] One embodiment addresses all or some of the shortcomings of known methods for separating lithium from lithium-bearing liquids.

[0011] One embodiment provides a method for separating lithium from a lithium mixture, the method comprising: providing a first mixture comprising at least a first compound of lithium, lithium hydride, and lithium deuterium and lithium tritide, the first mixture being at a first temperature; a first agitation step adapted to agitate the first mixture; a first cooling step adapted to cool the first mixture to a second temperature, preferably uniformly, lower than the first temperature, the first stirring step and the first cooling step adapted to deposit at least a portion of the first compound; a first separation step adapted to separate at least the deposited first compound from the first mixture to form a second mixture comprising at least lithium and lithium hydride, or a fifth mixture comprising at least lithium.

[0012] In one embodiment, the first compound is lithium tritide, the first temperature is greater than 691° C., the second temperature is between 689° C. and 691° C., for example equal to about 690° C., and the first separation step forms a second mixture.

[0013] In one embodiment, the first stirring step and the first cooling step are adapted to deposit at least a portion of the first compound and at least a portion of the lithium hydride, and the first separating step forms a fifth mixture.

[0014] In one embodiment, the first compound is lithium tritide and the first mixture further comprises lithium deuteride as a second compound, the first stirring step and the first cooling step are adapted to deposit at least a portion of the lithium deuteride and lithium tritide and at least a portion of the lithium hydride, and the first separation step forms a fifth mixture.

[0015] In one embodiment, the first temperature is greater than 691°C and the second temperature is between 687-689°C, for example equal to about 688°C.

[0016] In one embodiment, the method further comprises a first extraction step adapted to extract the deposited compound(s) after or during the first separation step.

[0017] In one embodiment, the method includes repeating the first agitation step, the first cooling step, and the first separation step, and optionally the first extraction step.

[0018] In one embodiment, the first mixture includes a second compound of lithium deuteride and lithium tritide that is different from the first compound, and the method further includes: a second agitation step adapted to agitate the second mixture; a second cooling step adapted to cool the second mixture to a third temperature, preferably uniformly, lower than the second temperature, the second stirring step and the second cooling step adapted to deposit at least a portion of the second compound; and a second separation step adapted to separate the deposited second compound from the second mixture to form a third mixture comprising at least lithium and lithium hydride.

[0019] In one embodiment, the method further comprises a second extraction step adapted to extract a second compound after or during the second separation step.

[0020] In one embodiment, the second compound is lithium deuteride and the third temperature is between 687 and 689°C, for example equal to about 688°C.

[0021] In one embodiment, the method includes repeating the second agitation step, the second cooling step, and the second separation step, and optionally the second extraction step.

[0022] In one embodiment, the method further comprises: a third agitation step adapted to agitate the third mixture; a third cooling step adapted to cool the third mixture to a fourth temperature, preferably uniformly, lower than the third temperature, the third stirring step and the third cooling step adapted to deposit at least a portion of the lithium hydride; and a third separation step adapted to separate the deposited lithium hydride from the third mixture to form a fourth mixture comprising at least lithium.

[0023] In one embodiment, the method further comprises a third extraction step adapted to extract lithium hydride after or during the third separation step.

[0024] In one embodiment, the fourth temperature is between 685°C and 687°C, for example equal to about 686°C.

[0025] In one embodiment, the method includes repeating the third agitation step, the third cooling step, and the third separation step, and optionally the third extraction step.

[0026] In one embodiment, the method further comprises a neutron bombardment and / or plasma exposure step applied to the second mixture, the third mixture, the fourth mixture, and / or the fifth mixture, e.g., to recreate a mixture similar to the first mixture.

[0027] In one embodiment, providing the first mixture includes a heating step adapted to heat the first mixture to a first temperature.

[0028] In one embodiment, the first mixture is in liquid or molten form.

[0029] One embodiment provides a method for separating lithium from a lithium mixture, the method comprising: providing a first mixture comprising at least a first compound of lithium, lithium hydride, and lithium deuterium and lithium tritide, the first mixture being at a first temperature; a first agitation step adapted to agitate the first mixture; a first cooling step adapted to cool the first mixture to a second temperature, preferably uniformly, lower than the first temperature, the first stirring step and the first cooling step adapted to deposit at least a portion of the first compound; a first separation step adapted to separate at least the deposited first compound from the first mixture to form a second mixture lean to at least the first compound; a first extraction step adapted to extract the separated first compound after or during the first separation step.

[0030] In one embodiment, the method includes repeating the first agitation step, the first cooling step, the first separation step, and the first extraction step.

[0031] In one embodiment, the first temperature is greater than 691°C and the second temperature is less than or equal to 691°C.

[0032] In one embodiment, the first mixture includes a second compound of lithium deuteride and lithium tritide that is different from the first compound, the first stirring step and the first cooling step are adapted to deposit at least a portion of the first compound and the second compound and at least a portion of the lithium hydride, and the second mixture is depleted in lithium hydride, lithium deuteride, and lithium tritide.

[0033] In one embodiment, the first temperature is greater than about 691°C and the second temperature is less than or equal to 687°C.

[0034] In one embodiment, the first mixture includes a second compound of lithium deuteride and lithium tritide that is different from the first compound, and the method further includes: a second agitation step adapted to agitate the second mixture; a second cooling step adapted to cool the second mixture to a third temperature, preferably uniformly, lower than the second temperature, the second stirring step and the second cooling step adapted to deposit at least a portion of the second compound; a second separation step adapted to separate the deposited second compound from the second mixture to form a third mixture depleted in the first compound and the second compound; a second extraction step adapted to extract the separated second compound after or during the second separation step.

[0035] In one embodiment, the method includes repeating the second agitation step, the second cooling step, the second separation step, and the second extraction step.

[0036] In one embodiment, the first temperature is greater than 691°C, the second temperature is less than or equal to 691°C, and the third temperature is less than or equal to 689°C.

[0037] In one embodiment, the method further comprises: a third agitation step adapted to agitate the third mixture; a third cooling step adapted to cool the third mixture to a fourth temperature, preferably uniformly, lower than the third temperature, the third stirring step and the third cooling step adapted to deposit at least a portion of the lithium hydride; a third separation step adapted to separate the deposited lithium hydride from the third mixture to form a fourth mixture depleted in lithium hydride, lithium deuterium, and lithium tritide; a third extraction step adapted to extract the separated lithium hydride after or during the third separation step.

[0038] In one embodiment, the method includes repeating the third agitation step, the third cooling step, the third separation step, and the third extraction step.

[0039] In one embodiment, the first temperature is greater than 691°C, the second temperature is less than or equal to 691°C, the third temperature is less than or equal to 689°C, and the fourth temperature is less than or equal to 687°C.

[0040] In one embodiment, the first temperature, the second temperature, and, for example, the third temperature and / or the fourth temperature are determined using a Li / LiH phase diagram, a Li / LiD phase diagram, and / or a Li / LiT phase diagram.

[0041] In one embodiment, the molar concentration of lithium hydride, lithium deuteride and / or lithium tritide in the first mixture is comprised between 2 and 95%, such as between 2.5 and 95%.

[0042] In one embodiment, each of the second temperature, the third temperature, and the fourth temperature is greater than 200°C, such as greater than 210°C.

[0043] In one embodiment, the method further comprises a neutron bombardment and / or plasma exposure step applied to the second mixture, the third mixture, and / or the fourth mixture, e.g., to recreate a mixture similar to the first mixture.

[0044] In one embodiment, providing the first mixture comprises a heating step adapted to heat the first mixture to a first temperature and / or the first mixture is in liquid or molten form.

[0045] An embodiment provides an apparatus adapted to perform a method according to an embodiment, the apparatus comprising: a container adapted to contain a mixture comprising at least one compound of lithium, lithium hydride, and lithium deuteride and / or lithium tritide; an agitator adapted to agitate the mixture in the vessel; and a cooling mechanism adapted to cool the mixture in the container. [Brief description of the drawings]

[0046] 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.

[0047] [Figure 1A] FIG. 1 shows a diagram of an embodiment of a method for extracting lithium hydride. [Figure 1B] FIG. 1 shows a diagram of another embodiment of a method for extracting lithium hydride. [Diagram 2] FIG. 1 shows a front view of an apparatus for carrying out the lithium hydride extraction method. [Diagram 3] The Li / LiH phase diagram as a function of the LiH molar concentration is shown. [Figure 4] The Li / LiH and Li / LiD phase diagrams are shown as a function of the LiH and LiD molar concentrations, respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] 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.

[0049] 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.

[0050] 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 that the two elements may be bonded via one or more other elements.

[0051] 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.

[0052] Unless otherwise specified, the terms "about," "approximately," "substantially," and "on the order of" mean within 10%, preferably within 5%.

[0053] The drawings are not to scale. It should be noted that the drawings show one embodiment of the disclosed method and apparatus for the extraction of lithium hydride, which may be described simply 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 have been emphasized for ease of understanding. The disclosed embodiments and the alternatives envisaged should not be considered as limiting the invention in any manner.

[0054] A diagram of an embodiment of a method for extracting lithium hydride is shown in Figure 1 A. It may be possible to start this process at any step or follow a different sequence to achieve the same result.

[0055] The method may begin with a liquid or molten Li / LiH / LiD / LiT mixture 104 (first mixture), which may then be heated to a first temperature in a first heating step or step 106 and then stirred in a first stirring step 108. The mixture may then be uniformly cooled in a first uniform cooling step 110 until it reaches a second temperature, which may be, for example, about 690° C., depicted in FIG. 1A as 690° C. mixture 112. At this point, deposition of LiT occurs in a LiT deposition step 114. After LiT is deposited, the next step is separation of LiT from the remaining mixture in a LiT separation step 116. At this point in the method, LiT may be extracted in a LiT extraction step 126.

[0056] Once the LiT has been extracted, the mixture remaining in the liquid phase is a Li / LiH / LiD mixture 118 (second mixture). The mixture having these compounds may then be subjected to a second stirring step 120 and then a second uniform cooling step 122 until the mixture reaches a third temperature, which may be about 688° C., which is depicted in the figure as mixture at 688° C. 124. With the mixture at this temperature, deposition of LiD occurs in a LiD deposition step 132. Once deposition is complete, LiD begins to separate in a LiD separation step 130. Once separation of LiD from the molten mixture is complete, LiD may be extracted from the mixture in a LiD extraction step 138.

[0057] Once the LiD has been extracted, the remaining mixture is a Li / LiH mixture 128 (third mixture). At this point, the Li / LiH mixture may again be stirred in a third stirring step 134 and cooled again in a third uniform cooling step 136 until the mixture reaches a fourth temperature, which may be 686° C., depicted in the figure as 686° C. mixture 140. At this temperature, LiH begins to deposit in a LiH deposition step 146. Once deposition is complete, the LiH can be separated in a LiH separation step 144. Once the LiH has separated, the LiH may be extracted from the mixture in a LiH extraction step 148. At this point, the mixture is composed solely or primarily of molten Li 142 (fourth mixture).

[0058] To regenerate the Li / LiH / LiD / LiT mixture 104, any of the Li / LiH / LiD mixture 118, the Li / LiH mixture 128, or the Li mixture 142 may be subjected to a deuterium-tritium plasma exposure and / or neutron bombardment step 102. The method described with respect to Figure 1A may then be resumed, or the method described below with respect to Figure 1B may be commenced.

[0059] It should be noted that several steps may be performed simultaneously, for example, a stirring step, i.e., the first stirring step 108, the second stirring step 120 or the third stirring step 134, may be performed during an associated cooling step, i.e., the first uniform cooling step 110, the second uniform cooling step 122 or the third uniform cooling step 136, respectively.

[0060] Uniform cooling (or uniformly cooled) refers to cooling that is substantially uniform throughout the entire volume of the mixture.

[0061] By LiT, LiD, LiH, or Li compound, it is meant that the compound contains predominantly or predominantly LiT, LiD, LiH, or Li, respectively, in other words, the compound is not necessarily pure LiT, LiD, LiH, or Li. Similarly, a Li / LiH / LiD mixture may contain residual traces of LiT, and a Li / LiH mixture may contain residual traces of LiT and / or LiD. The same is true for other mixtures of lithium and / or lithium ionic compounds.

[0062] The temperatures shown in FIG. 1A are representative temperatures and may depend on the concentration of lithium hydride in the mixture.

[0063] Depending on the concentration of lithium hydride in the mixture, this process may follow a different sequence, for example, cooling to deposit / separate LiH, then cooling again to deposit / separate LiD, then cooling again to deposit / separate LiT.

[0064] A diagram of another embodiment of a method for the extraction of lithium hydride is shown in FIG. 1B, in which collective precipitation of LiH and / or LiD and / or LiT is performed by cooling the Li / LiH / LiD / LiT mixture, for example to 686° C.

[0065] Similar to the method of FIG. 1A, the method of FIG. 1B may begin with a liquid or molten Li / LiH / LiD / LiT mixture 104 (first mixture), which may then be heated in a first heating step, or first heating step 106, and then stirred in a first stirring step 108.

[0066] The mixture may then be uniformly cooled in a first uniform cooling step 210 until it reaches a first temperature, which may be 686° C., and is depicted in FIG. 1B as 686° C. mixture 212.

[0067] At this point, deposition of LiH / LiD / LiT occurs in LiH / LiD / LiT deposition step 214. After the LiH / LiD / LiT is deposited, the next step is separation of the LiH / LiD / LiT from the remaining mixture in LiH / LiD / LiT separation step 216. The LiH / LiD / LiT may be extracted at this point in the method. Once the LiH / LiD / LiT is extracted, the mixture remaining in the liquid phase is a Li / LiH / LiD-lean mixture 218 (the second mixture, or the fifth mixture).

[0068] The Li / LiH / LiD lean mixture 218 may be subjected to deuterium-tritium plasma exposure and / or neutron bombardment step 102 to regenerate the Li / LiH / LiD / LiT mixture 104. The method described with respect to FIG. 1B may then be resumed, or the method described with respect to FIG. 1A may be commenced.

[0069] The temperatures shown in FIG. 1B are indicative temperatures and may depend on the concentration of lithium hydride in the mixture.

[0070] One embodiment of an apparatus 200 for carrying out this method is shown in FIG. 2. In this first embodiment, the apparatus includes a mechanism for rotating the mixture 204 (which may be an agitator 208), a mechanism for removing the precipitate 206 (which may be described as a paddle 212), and a mechanism for heating or cooling (which may be a serpentine tube 210 through which hot or cold water or another fluid may be used to heat or cool the mixture 204). All of this is maintained within a container 202, which may be insulated, and which has a hole 214 (opening) for the introduction and removal of the mixture 204. It is noted that the composition of the mixture 204 may be any of the Li / LiH / LiD / LiT mixture 104 from FIG. 1A, the Li / LiH / LiD mixture 118, the Li / LiH mixture 128, the Li mixture 142, or the Li / LiH / LiD-lean mixture 218 from FIG. 1B. Precipitate 206 may consist of the product of either the separation step or the deposition step and may effectively provide LiT extraction in step 126, LiD extraction in step 138 or LiH extraction in step 148.

[0071] Example of operation The operation of the apparatus of the described embodiment may be illustrated by the trajectory lines shown in Figure 3. Furthermore, the method described in Figure 1A or Figure 1B may also be performed by these trajectory lines.

[0072] A first trajectory 302 occurs at a LiH molar concentration of about 20% in the LiH mixture. In this first trajectory, at temperatures above about 690° C., the LiH mixture is in an alpha liquid phase, α(l). As the LiH mixture cools along trajectory 302, it enters two phases: an alpha liquid phase, α(l), and a beta solid phase, β(s). The beta solid phase, β(s), can be removed and retrieved as precipitate 206 from FIG. 2.

[0073] A second trajectory 304 may also be used in which the LiH molar concentration is about 30%. In this second trajectory 304, at temperatures above about 750° C., the mixture is in an alpha liquid phase, α(l). As the mixture is cooled along trajectory 304, and the mixture is below about 750° C. and above about 690° C., the liquid mixture separates into two distinct liquid phases, alpha phase, α(l) and beta phase, β(l). Then, as cooling continues below 690° C., the beta liquid phase solidifies and forms a beta solid phase, β(s), which may be removed and withdrawn as precipitate 206 from FIG. 2.

[0074] A third trajectory 306, where the molar concentration of LiH is about 95%, may start with a beta liquid phase β(l) at a temperature above 750° C. Along the third trajectory 306, the alpha and beta liquid phases separate as the mixture cools below 750° C. but above 690° C. Further, the beta phase solidifies again as the mixture cools below 690° C. The beta solid phase β(s) may be removed and retrieved as the precipitate 206 from FIG. 2.

[0075] More generally, other trajectories with LiH molar concentrations greater than 2% or 2.5% and less than about 95% may also be used.

[0076] It is understood that the actual molar concentrations of the compounds in the lithium hydride mixture may differ from those described herein, and the actual temperatures at which the changes occur (transition temperatures) may also differ from those described above, but it will be apparent to one skilled in the art that the phase separation will achieve the same results despite different conditions.

[0077] For example, it will be appreciated that the locus 302 at about 20% LiH molar concentration is representative of other similar vertical loci in Figure 3 where the same phase transition from alpha liquid to two distinct phases, i.e., alpha liquid and beta solid, occurs, but at other LiH molar concentrations between about 2% or 2.5% and 25%, i.e., about 25% LiH molar concentration, which corresponds to point A on the phase diagram. For any LiH molar concentration in that range, the corresponding transition temperature can be determined from the phase diagram of Figure 3 or any other Li / LiH phase diagram.

[0078] Similarly, the locus 304 at about 30% LiH molar concentration is representative of another transition from the alpha liquid phase to two different alpha and beta liquid phases, and then to the alpha liquid and beta solid phases, at LiH molar concentrations between about 25% and 70%. For any LiH molar concentration in that range, the corresponding transition temperatures can be determined from the phase diagram of FIG. 3 or any other Li / LiH phase diagram.

[0079] Similarly, the locus 306 at about 95% LiH molar concentration is representative of another transition from the beta liquid phase to two different alpha and beta liquid phases, and then to the alpha liquid and beta solid phases, at LiH molar concentrations between about 70% and 95%. For any LiH molar concentration in that range, the corresponding transition temperatures can be determined from the phase diagram of FIG. 3 or any other Li / LiH phase diagram.

[0080] Figure 4 shows the Li / LiH and Li / LiD phase diagrams as a function of the LiH and LiD molar concentrations, respectively, with the molar concentrations on the horizontal axis plotted on a logarithmic scale.

[0081] FIG. 4 shows that the Li / LiH and Li / LiD phase diagrams have similar shapes, but are substantially shifted by a few degrees for each concentration. Thus, FIG. 4 shows that it is possible to manipulate the temperature for separately precipitating LiH and LiD from a mixture containing at least Li, LiH, and LiD at different molar concentrations. The transition temperatures for precipitating LiH and LiD, respectively, depend on the respective molar concentrations of LiH and LiD in the mixture.

[0082] In one example, considering part B of the phase diagram corresponding to a molar concentration of less than about 25%, which is the molar concentration corresponding to point A, one can start at a first temperature in the alpha liquid phase α(l), which corresponds to the upper region of the two phase diagrams in part B, and then the temperature can be reduced to a temperature given by the Li / LiD phase diagram to precipitate LiD (beta solid phase β(s) of LiD), and the temperature can be reduced again a few degrees to a temperature given by the Li / LiH phase diagram to precipitate LiH (beta solid phase β(s) of LiH).

[0083] In another example, considering part C of the phase diagram, which corresponds to a molar concentration higher than about 25%, one can start at a first temperature in the alpha liquid phase α(l), or the alpha and beta liquid phases α(l)+β(l), which correspond to the upper region of the two phase diagrams in part C, and then the temperature can be reduced to a temperature given by the Li / LiH phase diagram to precipitate LiH, and again reduced a few degrees to a temperature given by the Li / LiD phase diagram to precipitate LiD.

[0084] Although not shown in FIG. 4, the Li / LiT phase diagram is similar to the Li / LiH and Li / LiD phase diagrams, for example, as described in "Applied Chemistry of Alkali Metals" by Hans U. Borgostedt and Cherian K. Matthews, p. 136. The Li / LiT phase diagram can be a few degrees higher than the Li / LiD phase diagram in part B and a few degrees lower than the Li / LiD phase diagram in part C. In one example, starting from a first temperature in the alpha liquid phase α(l) in part B of the phase diagram, the temperature can be lowered to precipitate LiT, then lowered again a few degrees to precipitate LiD, and then lowered again a few degrees to precipitate LiH. In another example, starting from a first temperature in the alpha liquid phase α(l) or in the alpha and beta liquid phases α(l)+β(l) in part C of the phase diagram, the temperature can be lowered to precipitate LiH, then lowered again a few degrees to precipitate LiD, and then lowered again a few degrees to precipitate LiT.

[0085] It is also evident from FIG. 4 that the temperature can be reduced to co-precipitate LiH / LiD or co-precipitate LiH / LiD / LiT.

[0086] More generally, Figures 3 and 4 show that for any concentration of compound(s) to be separated from Li, e.g., 2% to 95% molar concentration, transition temperatures adapted to effect the separation can be determined using Li / LiX phase diagram(s), where X is H, D and / or T.

[0087] The apparatus shown in Fig. 2 performs each step of the method shown in Fig. 1A or Fig. 1B. The serpentine tube 210 can be used for either the first heating step 160 or the cooling step, i.e., the first uniform cooling step 110, 210, the second uniform cooling step 122 or the third uniform cooling step 136. The agitator 208 can be used for the agitation step, i.e., the first agitation step 108, the second agitation step 120 or the third agitation step 134. Furthermore, the paddle 212 can be used to remove the precipitate 206, which is the product of the separation and precipitation step. The extraction step can be performed by the paddle 212 removing the precipitate 206 through one of the holes 214 of the vessel, which can be achieved by pressing.

[0088] Illustrative embodiments of the present invention are summarized here. Other embodiments may be understood from the entire specification, as well as the claims set forth herein.

[0089] Example 1. 1. A method for separating lithium from a lithium mixture comprising the steps of: providing a first mixture (104) comprising at least a first compound of lithium, lithium hydride, and lithium deuterium and lithium tritide, the first mixture being at a first temperature; a first agitation step (108) adapted to agitate the first mixture; a first cooling step (110, 210) adapted to cool the first mixture to a second temperature, preferably uniformly, lower than the first temperature, the first stirring step and the first cooling step adapted to deposit at least a portion of the first compound; a first separation step (116, 216) adapted to separate at least the deposited first compound from the first mixture to form a second mixture (118) comprising at least lithium and lithium hydride, or a fifth mixture (218) comprising at least lithium; The method includes:

[0090] Example 2. 2. The method of example 1, wherein the first compound is lithium tritide, the first temperature is greater than 691° C., the second temperature is between 689° C. and 691° C., e.g., equal to about 690° C., and the first separation step (116) forms a second mixture (118).

[0091] Example 3. 2. The method of claim 1, wherein the first stirring step (108) and the first cooling step (210) are adapted to deposit at least a portion of the first compound and at least a portion of the lithium hydride, and the first separating step (116) forms a fifth mixture (218).

[0092] Example 4. 2. The method of example 1, wherein the first compound is lithium tritide and the first mixture (104) further comprises lithium deuterium as a second compound, and the first stirring step (108) and the first cooling step (210) are adapted to deposit at least a portion of the lithium deuterium and lithium tritide and at least a portion of the lithium hydride to form a fifth mixture (218).

[0093] Example 5. 5. The method according to claim 3 or 4, wherein the first temperature is greater than 691°C and the second temperature is between 687°C and 689°C, for example equal to about 688°C.

[0094] Example 6. The method of any one of Examples 1 to 5, further comprising a first extraction step (126) adapted to extract the deposited compound(s) after or during the first separation step.

[0095] Example 7. The method according to any one of Examples 1 to 6, comprising repeating the first stirring step, the first cooling step and the first separation step, and optionally the first extraction step.

[0096] Example 8. the first mixture (104) comprises a second compound of lithium deuterium and lithium tritium, different from the first compound; a second agitation step (120) adapted to agitate the second mixture; a second cooling step (122) adapted to cool the second mixture to a third temperature, preferably uniformly, lower than the second temperature, the second stirring step and the second cooling step adapted to deposit at least a portion of the second compound; The method of any one of Examples 1, 2, 6, and 7, further comprising a second separation step (130) adapted to separate the deposited second compound from the second mixture to form a third mixture (128) comprising at least lithium and lithium hydride.

[0097] Example 9. 9. The method of example 8, comprising after the second separation step (130) or during the second separation step (130), a second extraction step (138) adapted to extract a second compound.

[0098] Example 10. 10. The method of any one of claims 8 to 9, wherein the second compound is lithium deuteride and the third temperature is between 687°C and 689°C, such as approximately equal to 688°C.

[0099] Example 11. The method according to any one of Examples 8 to 10, comprising repeating the second stirring step, the second cooling step and the second separation step, and optionally the second extraction step.

[0100] Example 12. a third agitation stage (134) adapted to agitate the third mixture (128); a third cooling step (136) adapted to cool the third mixture to a fourth temperature, preferably uniformly, lower than the third temperature, the third stirring step and the third cooling step adapted to deposit at least a portion of the lithium hydride; a third separation step (144) adapted to separate the deposited lithium hydride from the third mixture to form a fourth mixture (142) containing at least lithium; The method according to any one of Examples 8 to 11, further comprising:

[0101] Example 13. 13. The method of example 12, further comprising a third extraction step (148) adapted to extract lithium hydride after or during the third separation step (144).

[0102] Example 14. 14. The method of claim 12 or 13, wherein the fourth temperature is between 685°C and 687°C, for example equal to about 686°C.

[0103] Example 15. The method of any one of Examples 12-14, comprising repeating the third stirring step, the third cooling step and the third separation step, and optionally the third extraction step.

[0104] Example 16. The method of any one of Examples 1 to 15, further comprising a neutron bombardment and / or plasma exposure step (102) applied to the second mixture (118), the third mixture (128), the fourth mixture (142), and / or the fifth mixture (218), e.g. to recreate a mixture similar to the first mixture (104).

[0105] Example 17. The method of any one of Examples 1-16, wherein the step of providing a first mixture (104) comprises a heating step (106) adapted to heat the first mixture to a first temperature.

[0106] Example 18. The method of any one of Examples 1 to 17, wherein the first mixture (104) is in liquid or molten form.

[0107] Example 19. An apparatus adapted to carry out the method according to any one of Examples 1 to 18, a container (202) adapted to contain a mixture (204) including at least one compound of lithium, lithium hydride, and lithium deuteride and / or lithium tritide; an agitator (208) adapted to agitate the mixture within the vessel; a cooling mechanism (210) adapted to cool the mixture within the container; 13. An apparatus comprising:

[0108] Example 20. 20. The apparatus of example 19, wherein the cooling mechanism (210) is also adapted to heat the mixture (204), e.g., the cooling mechanism comprises a serpentine tube.

[0109] Example 21. 21. The apparatus of example 19 or 20, wherein the container comprises at least one opening (214) adapted to admit and withdraw at least a portion of the mixture.

[0110] Example 22. The apparatus of any one of Examples 19 to 21, further comprising a removal mechanism (212) adapted to remove at least a portion of the mixture from the container.

[0111] Various embodiments and variations have been described, and those of ordinary skill in the art will recognize that certain features of these embodiments can be combined and other variations will readily occur to those of ordinary skill in the art.

[0112] 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.

[0113] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 22305438, filed April 4, 2022, entitled "Apparatus and Method for Extraction of Lithium Hydride," on the filing date thereof, the disclosure of which is incorporated herein by reference to the maximum extent permitted by law.

[0114] Acronym Explanation LiH: Lithium hydride LiD: Lithium deuteride LiT: Lithium tritide LiCl: Lithium chloride LiF: Lithium fluoride LiBr: Lithium bromide HCL: Hydrochloric acid HF: Hydrofluoric acid HBr: Hydrobromic acid LiOH: Lithium hydroxide Li2CO3: Lithium carbonate Li: Lithium

Claims

1. A method for separating lithium from a lithium mixture, A step of providing a first mixture comprising lithium, lithium hydride, and at least a first compound from among lithium deuteride and lithium tritiide, and at a first temperature; A first stirring step adapted to stir the first mixture, A first cooling step adapted to cool the first mixture to a second temperature lower than the first temperature, preferably uniformly, wherein the first stirring step and the first cooling step are adapted to deposit at least a portion of the first compound, A first separation step adapted to separate at least the deposited first compound from the first mixture and to form a second mixture that is at least poor in the first compound, A first extraction step adapted to extract the separated first compound after or during the first separation step, Methods that include...

2. The method according to claim 1, comprising repeating the first stirring step, the first cooling step, the first separation step, and the first extraction step.

3. The method according to claim 1, wherein the first temperature is higher than 691°C and the second temperature is 691°C or lower.

4. The method according to claim 1, wherein the first mixture comprises a second compound, which is different from the first compound, and which is one of lithium deuteride and lithium tritiate, and the first stirring step and the first cooling step are adapted to deposit at least a portion of the first and second compounds, as well as at least a portion of lithium hydride, and the second mixture is poor in lithium hydride, lithium deuteride, and lithium tritiate.

5. The method according to claim 4, wherein the first temperature is higher than approximately 691°C and the second temperature is 687°C or lower.

6. The first mixture comprises a second compound, which is different from the first compound, and is one of lithium deuteride and lithium tritiate. A second stirring step adapted to stir the second mixture, A second cooling step, adapted to cool the second mixture to a third temperature lower than the second temperature, preferably uniformly, wherein the second stirring step and the second cooling step are adapted to deposit at least a portion of the second compound, A second separation step adapted to separate the deposited second compound from the second mixture to form a third mixture deficient in the first and second compounds, A second extraction step, adapted to extract the separated second compound after or during the second separation step, The method according to claim 1, further comprising:

7. The method according to claim 6, comprising repeating the second stirring step, the second cooling step, the second separation step, and the second extraction step.

8. The method according to claim 6, wherein the first temperature is higher than 691°C, the second temperature is 691°C or less, and the third temperature is 689°C or less.

9. A third stirring step adapted to stir the third mixture, A third cooling step adapted to cool the third mixture to a fourth temperature lower than the third temperature, preferably uniformly, wherein the third stirring step and the third cooling step are adapted to deposit at least a portion of the lithium hydride, A third separation step adapted to separate the deposited lithium hydride from the third mixture to form a fourth mixture poor in lithium hydride, lithium deuteride, and lithium tritiate, A third extraction step adapted to extract the separated lithium hydride after or during the third separation step, The method according to claim 6, further comprising:

10. The method according to claim 9, comprising repeating the third stirring step, the third cooling step, the third separation step, and the third extraction step.

11. The method according to claim 9, wherein the first temperature is higher than 691°C, the second temperature is 691°C or less, the third temperature is 689°C or less, and the fourth temperature is 687°C or less.

12. The method according to claim 9, wherein the first temperature, the second temperature, and, for example, the third temperature and / or the fourth temperature are determined using a Li / LiH phase diagram, a Li / LiD phase diagram and / or a Li / LiT phase diagram.

13. The method according to claim 1, wherein the molar concentration of lithium hydride, lithium deuteride and / or lithium tritiate in the first mixture is 2 to 95%, for example, 2.5% to 95%.

14. The method according to claim 9, wherein each of the second temperature, the third temperature, and the fourth temperature is higher than 200°C, for example, higher than 210°C.

15. The method according to claim 9, further comprising a neutron collision and / or plasma exposure step applied to the second mixture, the third mixture, and / or the fourth mixture to regenerate a mixture similar to the first mixture, for example.

16. The step of providing the first mixture includes a heating step adapted to heat the first mixture to the first temperature, and / or The method according to claim 1, wherein the first mixture is in liquid or molten form.

17. An apparatus adapted to carry out the method described in any one of claims 1 to 16, A container adapted to contain a mixture comprising lithium, lithium hydride, and at least one compound of lithium deuteride and / or lithium tritiate, A stirrer adapted for stirring the mixture in the container, A cooling mechanism adapted to cool the mixture in the container, A device including a device.

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