Apparatus and method for extracting lithium hydride

Abstract

The present disclosure relates to a method for separating lithium from a lithium mixture, the method comprising: providing a first mixture (104) comprising at least a first compound of lithium deuteride and lithium tritide, lithium and lithium hydride, the first mixture being 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 to a second temperature lower than the first temperature, preferably uniformly to the second temperature; the first stirring step and the first cooling step are adapted to deposit at least a portion of the first compound; and a first separation step (116) adapted to separate at least the deposited first compound from the first mixture, forming a second mixture (118) comprising at least lithium and lithium hydride.

Description

[0001] This application is based on European patent application No. 22305438 filed on April 4, 2022, entitled "DEVICE AND METHOD FOR EXTRACTION OF LITHIUM HYDRIDES", and claims the priority benefit of that application, which is incorporated into this application by reference to the maximum extent permitted by law. Technical Field

[0002] The present disclosure relates to apparatus and methods for separating lithium hydrides in liquid mixtures, and in particular to separating lithium hydride, lithium deuteride and lithium tritide from lithium-containing mixtures. Background Art

[0003] Currently, the world is heavily dependent on fossil fuels, a dependence that has serious consequences for climate, climate warming, and biosphere degradation. The only alternative energy source known to humanity is nuclear energy, and the only energy source that can achieve adequate safety and fuel efficiency is nuclear fusion energy.

[0004] The promise of nuclear fusion energy brings up the problem of tritium breeding. In fact, the most efficient nuclear fusion reaction is deuterium-tritium, which requires a 50%-50% mixture of deuterium and tritium. Therefore, tritium represents half of the most efficient nuclear fusion reaction and is also a very scarce hydrogen isotope. It is calculated that there are about 20 kilograms of tritium naturally present, so to use it as fuel, tritium must be artificially generated. Currently, the price of one gram of tritium is about $30,000.

[0005] Currently, the method of producing tritium in a nuclear fusion reactor involves collecting it from a lithium blanket or breeder reactor. Neutrons are expelled as part of the nuclear fusion reaction process, which then causes the lithium to react with the neutrons and produce tritium. The lithium blanket can be made of solid lithium or liquid lithium.

[0006] After the lithium blanket is bombarded with neutrons, the reaction products remain in the blanket. Since the products are in the blanket, they need to be extracted. For liquid blankets, this presents additional problems. Neutron bombardment of lithium produces many products from the initial reaction or subsequent reactions, most of which are helium and tritium. In addition, the environment in which these products are formed promotes the subsequent reaction of tritium with lithium, which leads to the formation of lithium tritiated LiT; coupled with the exposure of lithium to deuterium tritium plasma, this also leads to the formation of lithium deuterated LiD. These compounds appear in the liquid blanket along with pure lithium and other impurities, and they must be separated to extract and reuse the tritium. Another compound - lithium hydride LiH - although it does not form spontaneously, neither on exposure to neutrons nor on deuterium tritium plasma, can be added to the liquid blanket to promote the above separation. The following ionic compounds can all be named "lithium hydrides": lithium hydride LiH, lithium deuterated LiD, and lithium tritiated LiT.

[0007] Currently, the industry uses methods with some limitations when facing this problem. The prior art teaches the Maroni process using high temperature molten mixed alkali metal halide salts (LiCl:LiF:LiBr) as extraction solvents. As is known, this process produces impurities such as liquid and gaseous acids such as HCl, HF and HBr in the salt phase, so these solvents are very corrosive and volatile.

[0008] One of these methods is described in US 10,450,600 to Garcia-Diaz et al. In this document, an electrochemical cell is used to recover tritium from a molten lithium metal solution. This method has some limitations that prevent it from being used in certain applications, such as as part of the operation of a nuclear fusion power plant. One limitation is that the lithium mixture must be treated with an electrolyte, and therefore the composition of the mixture needs to be changed to add the electrolyte. Therefore, in the already time-sensitive process of the operating power plant, an additional step of adding the electrolyte to the mixture must be added. The second limitation of the method involves the electrochemical cell equipment. The mixture must be deposited on the cell and then there must be sufficient time for the electrochemical separation process. For some applications, including an electrochemical cell that can maintain the mixture at its operating temperature will be prohibitive. In addition, for time considerations, it may be necessary for the separation process to proceed faster, and in the method discussed in this document, which is described as using an electrochemical cell, it is not very obvious how to increase the separation speed. The last obvious limitation of the system is that it preferably produces tritium gas as one of the separation products. This is a severe limitation, as tritium must be converted into another state before it can be used in certain applications, significantly increasing the time requirements.

[0009] Other methods involve different solvents. Such a method is described in PCT application WO2013 / 166505 to Farmer. In Farmer's document, molten lithium compounds including LiOH and Li2CO3 can be used as solvents for extracting lithium tritiated from molten lithium metal. In particular, the use of LiOH avoids the generation of HF. However, the method described by Farmer also includes subjecting the extracted LiT solution to electrolysis in an electrochemical cell and does not overcome this limitation in the prior art.

[0010] Therefore, there remains a need for a method of separating lithium from the ionic compounds lithium tritiate and, if present, lithium hydride and / or lithium deuteride for use in the emerging nuclear fusion industry. A method that does not require important stages such as solvents or electrochemical cells. A reliable method or apparatus capable of separating these compounds from a mixture would greatly reduce costs and help make energy production using nuclear fusion reactions a cost-effective endeavor. Summary of the invention

[0011] One embodiment addresses all or part of the disadvantages of known methods for separating lithium from lithium-containing liquids.

[0012] One embodiment provides a method for separating lithium from a lithium mixture, the method comprising:

[0013] providing a first mixture, the first mixture comprising at least a first compound of lithium deuteride and lithium tritide, lithium, and lithium hydride, the first mixture being at a first temperature;

[0014] A first stirring step, adapted to stir the first mixture;

[0015] a first cooling step adapted to cool the first mixture to a second temperature lower than the first temperature, preferably uniformly to the second temperature; the first stirring step and the first cooling step adapted to deposit at least a portion of the first compound; and

[0016] The first separation step is suitable for separating at least the deposited first compound from the first mixture, thereby forming a second mixture comprising at least lithium and lithium hydride or a fifth mixture comprising at least lithium.

[0017] In one embodiment, the first compound is lithium tritiated, the first temperature is above 691° C., and the second temperature is between 689° C. and 691° C., such as equal to about 690° C., the first separation step forming the second mixture.

[0018] In one embodiment, the first stirring step and the first cooling step are suitable for depositing at least a portion of the first compound and at least a portion of the lithium hydride, and the first separating step forms the fifth mixture.

[0019] In one embodiment, the first compound is lithium tritide, the first mixture further comprises lithium deuteride as a second compound, the first stirring step and the first cooling step are suitable for depositing lithium deuteride and at least a portion of the lithium tritide and at least a portion of the lithium hydride, and the first separation step forms the fifth mixture.

[0020] In one embodiment, the first temperature is higher than 691°C and the second temperature is between 687°C and 689°C, for example equal to about 688°C.

[0021] In one embodiment, the method further comprises: a first extraction step, adapted to extract the deposited one or more compounds after or during the first separation step.

[0022] In one embodiment, the method further comprises repeating the first agitating step, the first cooling step, and the first separating step, and in some cases repeating the first extracting step.

[0023] In one embodiment, the first mixture includes a second compound of lithium deuteride and lithium tritide different from the first compound, and the method further includes:

[0024] A second stirring step, adapted to stir the second mixture;

[0025] a second cooling step adapted to cool the second mixture to a third temperature lower than the second temperature, preferably uniformly to the third temperature; the second stirring step and the second cooling step adapted to deposit at least a portion of the second compound; and

[0026] A second separation step is suitable for separating the deposited second compound from the second mixture, thereby forming a third mixture comprising at least lithium and lithium hydride.

[0027] In one embodiment, the method further comprises: a second extraction step, adapted to extract the second compound after or during the second separation step.

[0028] In one embodiment, the second compound is lithium deuteride and the third temperature is between 687°C and 689°C, such as equal to about 688°C.

[0029] In one embodiment, the method includes repeating the second agitating step, the second cooling step, and the second separating step, and in some cases repeating the second extracting step.

[0030] In one embodiment, the method further comprises:

[0031] A third stirring step, adapted to stir the third mixture;

[0032] a third cooling step adapted to cool the third mixture to a fourth temperature lower than the third temperature, preferably uniformly cooled to the fourth temperature; the third stirring step and the third cooling step adapted to deposit at least a portion of the lithium hydride; and

[0033] The third separation step is suitable for separating the deposited lithium hydride from the third mixture, thereby forming a fourth mixture including at least lithium.

[0034] In one embodiment, the method further comprises: a third extraction step, adapted to extract lithium hydride after or during the third separation step.

[0035] In one embodiment, the fourth temperature is between 685°C and 687°C, such as equal to about 686°C.

[0036] In one embodiment, the method includes repeating the third agitating step, the third cooling step, and the third separating step, and in some cases repeating the third extracting step.

[0037] In one embodiment, the method further comprises: a neutron bombardment and / or plasma exposure step, wherein the neutron bombardment and / or plasma exposure step is applied to the second mixture, the third mixture, the fourth mixture and / or the fifth mixture, for example to regenerate a mixture similar to the first mixture.

[0038] In one embodiment, providing the first mixture comprises a heating step, the heating step being adapted to heat the first mixture to the first temperature.

[0039] In one embodiment, the first mixture is in a liquid or molten state.

[0040] One embodiment provides a method for separating lithium from a lithium mixture, the method comprising:

[0041] providing a first mixture, the first mixture comprising at least a first compound of lithium deuteride and lithium tritide, lithium, and lithium hydride, the first mixture being at a first temperature;

[0042] A first stirring step, adapted to stir the first mixture;

[0043] a first cooling step adapted to cool the first mixture to a second temperature lower than the first temperature, preferably uniformly to the second temperature; the first stirring step and the first cooling step adapted to deposit at least a portion of the first compound;

[0044] a first separation step adapted to separate at least the deposited first compound from the first mixture, thereby forming a second mixture low in at least the first compound; and

[0045] The first extraction step is suitable for extracting the separated first compound after or during the first separation step.

[0046] In one embodiment, the method comprises: repeating the first stirring step, the first cooling step, the first separating step and the first extracting step.

[0047] In one embodiment, the first temperature is higher than 691°C and the second temperature is lower than or equal to 691°C.

[0048] 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 first stirring step and the first cooling step are suitable for depositing at least a portion of the first compound and the second compound and at least a portion of lithium hydride, and the second mixture has a low content of lithium hydride, lithium deuteride and lithium tritide.

[0049] In one embodiment, the first temperature is greater than about 691°C and the second temperature is less than or equal to 687°C.

[0050] In one embodiment, the first mixture includes a second compound of lithium deuteride and lithium tritide different from the first compound, and the method further includes:

[0051] A second stirring step, adapted to stir the second mixture;

[0052] a second cooling step adapted to cool the second mixture to a third temperature lower than the second temperature, preferably uniformly to the third temperature; the second stirring step and the second cooling step adapted to deposit at least a portion of the second compound;

[0053] a second separation step adapted to separate the deposited second compound from the second mixture, thereby forming a third mixture low in the first compound and the second compound; and

[0054] The second extraction step is suitable for extracting the separated second compound after or during the second separation step.

[0055] In one embodiment, the method comprises: repeating the second stirring step, the second cooling step, the second separation step and the second extraction step.

[0056] In one embodiment, the first temperature is higher than 691°C, the second temperature is lower than or equal to 691°C, and the third temperature is lower than or equal to 689°C.

[0057] In one embodiment, the method further comprises:

[0058] A third stirring step, adapted to stir the third mixture;

[0059] a third cooling step adapted to cool the third mixture to a fourth temperature lower than the third temperature, preferably uniformly cooled to the fourth temperature; the third stirring step and the third cooling step adapted to deposit at least a portion of the lithium hydride;

[0060] a third separation step adapted to separate the deposited lithium hydride from the third mixture, thereby forming a fourth mixture having low contents of lithium hydride, lithium deuteride and lithium tritide; and

[0061] The third extraction step is suitable for extracting the separated lithium hydride after or during the third separation step.

[0062] In one embodiment, the method includes: repeating the third stirring step, the third cooling step, the third separation step and the third extraction step.

[0063] In one embodiment, the first temperature is higher than 691°C, the second temperature is lower than or equal to 691°C, the third temperature is lower than or equal to 689°C, and the fourth temperature is lower than or equal to 687°C.

[0064] 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.

[0065] In one embodiment, the molar concentration of lithium hydride, lithium deuteride and / or lithium tritide in the first mixture is between 2% and 95%, such as between 2.5% and 95%.

[0066] In one embodiment, the second temperature, the third temperature and the fourth temperature are all higher than 200°C, such as higher than 210°C.

[0067] In one embodiment, the method further comprises: a neutron bombardment and / or plasma exposure step, which is applied to the second mixture, the third mixture and / or the fourth mixture, for example to regenerate a mixture similar to the first mixture.

[0068] In one embodiment:

[0069] Providing a first mixture comprises a heating step, wherein the heating step is suitable for heating the first mixture to the first temperature; and / or

[0070] The first mixture is in a liquid or molten state.

[0071] An embodiment provides a device suitable for implementing the method according to the embodiment, wherein the device comprises:

[0072] a container adapted to contain a mixture comprising at least one compound of lithium deuteride and / or lithium tritide, lithium, and lithium hydride;

[0073] an agitator, adapted to agitate the mixture in the container; and

[0074] A cooling mechanism is adapted to cool the mixture in the container. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The above features and advantages as well as other features and advantages will be described in detail in the following description of specific embodiments given by way of illustration and not limitation with reference to the accompanying drawings, in which:

[0076] Figure 1A is a diagram of one embodiment of a method for extracting lithium hydride.

[0077] Figure 1B is a diagram of another embodiment of a method for extracting lithium hydride.

[0078] Figure 2 is a front view of an apparatus for carrying out the method for extracting lithium hydride.

[0079] Figure 3 It is the Li / LiH phase diagram drawn according to the molar concentration of LiH.

[0080] Figure 4 Represents the Li / LiH and Li / LiD phase diagrams plotted according to the molar concentration of LiH and the molar concentration of LiD, respectively. DETAILED DESCRIPTION

[0081] In the various drawings, the same features are indicated by the same reference numerals. In particular, common structural and / or functional features in various embodiments may have the same reference numerals and may have the same structural characteristics, dimensional characteristics, and material characteristics.

[0082] For clarity, only the operations and elements that are helpful for understanding the embodiments described herein are described and illustrated in detail.

[0083] Unless otherwise specified, when referring to two elements being connected together, this means a direct connection without any intermediate elements except conductors, and when referring to two elements being coupled together, this means the two elements may be connected together or they may be coupled via one or more other elements.

[0084] In the following disclosure, unless otherwise stated, when referring to absolute position qualifiers such as terms "front", "back", "up", "down", "left", "right", or relative position qualifiers such as terms "above", "below", "high", "low", or orientation qualifiers such as "horizontal" and "vertical", they all refer to the orientation shown in the accompanying drawings.

[0085] Unless otherwise indicated, the expressions "about", "approximately", "substantially" and "approximately" mean within 10%, preferably within 5%.

[0086] The drawings are not drawn to scale. It should be noted that what is mentioned in the drawings is an embodiment of the disclosed method and apparatus for extracting lithium hydride, sometimes also referred to as apparatus or method. As will be readily understood by a properly trained person, other embodiments are possible. The actual size and / or shape of the components in the embodiments may vary. Only the important details of the embodiments are shown, but a person of ordinary skill in the art can understand how the entire apparatus can be constructed without excessive experimentation. Similarly, a person of ordinary skill in the art can foresee that the steps of the method can be performed in a different order depending on the specific needs of use. Some details are omitted in the drawings, but the inventor believes that adding these details is unnecessary for a full understanding of the features of the disclosed invention. These omitted details include elements for holding or fixing the device or its functional components, etc. For ease of understanding, certain features of the present embodiment are magnified. The disclosed embodiments and observed alternatives should not be construed as limiting the present invention in any way.

[0087] Figure 1A A diagram showing one embodiment of a method for extracting lithium hydride. The process can be started from any step or performed in a different order to achieve the same result.

[0088] The method may start with a liquid or molten Li / LiH / LiD / LiT mixture 104 (first mixture), which is then heated to a first temperature in a first heating step or first heating step 106, and then stirred in a first stirring step 108. The mixture is then uniformly cooled in a first uniform cooling step 110, for example, until the mixture reaches a second temperature, which may be about 690° C. Figure 1A The mixture is described as being at 690° C. step 112. At this point, deposition of LiT occurs in LiT deposition step 114. After LiT deposition, the next step is to separate the LiT from the rest of the mixture in LiT separation step 116. At this point in the process, the LiT can be extracted in LiT extraction step 126.

[0089] Once the LiT is extracted, the mixture remaining in the liquid phase is a Li / LiH / LiD mixture 118 (a second mixture). The mixture containing these compounds may then be subjected to a second stirring step 120, followed by a second uniform cooling step 122, until the mixture reaches a third temperature, which may be about 688°C, which step is depicted in the figure as the mixture being at 688°C 124. When the mixture is at this temperature, deposition of LiD occurs in a LiD deposition step 132. Once deposition is complete, LiD separation begins in a LiD separation step 130. With the separation of LiD from the molten mixture complete, LiD may be extracted from the mixture in a LiD extraction step 138.

[0090] Once the LiD is extracted, the remaining mixture is a Li / LiH mixture 128 (third mixture). At this point, the Li / LiH mixture can be stirred again in the third stirring step 134 and cooled again in the third uniform cooling step 136 until the mixture reaches a fourth temperature, which can be 686°C, which is depicted in the figure as the mixture being at 686°C 140. At this temperature, LiH begins to deposit in the LiH deposition step 146. Once the deposition is complete, the LiH can now be separated in the LiH separation step 144. When the LiH is separated, it can now be extracted from the mixture in the LiH extraction step 148. At this point, the mixture is entirely or primarily composed of molten Li 142 (fourth mixture).

[0091] Any mixture of Li / LiH / LiD 118, Li / LiH 128, or Li 142 can be subjected to deuterium tritium plasma exposure and / or neutron bombardment 102 to regenerate the Li / LiH / LiD / LiT mixture 104. The reaction with Figure 1A The method described in the related Figure 1B Related description methods.

[0092] It should be noted that some steps may be performed simultaneously, for example, the stirring step - the first stirring step 108, the second stirring step 120 or the third stirring step 134 - can occur during the accompanying cooling step - the first uniform cooling step 110, the second uniform cooling step 122 or the third uniform cooling step 136, respectively.

[0093] When referring to uniform cooling (or being uniformly cooled), it is meant that the cooling is substantially uniform throughout the volume of the mixture.

[0094] When LiT, LiD, LiH or Li compounds are mentioned, this means that the compound mainly contains or is rich in 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 trace amounts of LiT, and a Li / LiH mixture may contain trace amounts of LiT and / or LiD. The same applies to other mixtures of lithium and / or lithium ion compounds.

[0095] Figure 1A The temperatures shown in are indicative temperatures and may depend on the concentration of lithium hydride in the mixture.

[0096] Depending on the concentration of lithium hydride in the mixture, the process can follow another sequence, such as cooling and depositing / separating LiH, then cooling again and depositing / separating LiD, then cooling again and depositing / separating LiT.

[0097] Figure 1B A diagram showing another embodiment of a method for extracting lithium hydrides, wherein LiH and / or LiD and / or LiT are collectively precipitated by cooling the Li / LiH / LiD / LiT mixture to, for example, 686°C.

[0098] and Figure 1A Similar to the method, Figure 1B The method may start 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.

[0099] Then, the mixture may be uniformly cooled in the first step of uniform cooling 210 until the mixture reaches a first temperature, which may be 686° C. Figure 1B The mixture is described as being at 686°C 212.

[0100] At this point, deposition of LiH / LiD / LiT occurs in the LiH / LiD / LiT deposition step 214. After the LiH / LiD / LiT deposition, the next step is to separate the LiH / LiD / LiT from the rest of the mixture in the LiH / LiD / LiT separation step 216. At this point in the process, the LiH / LiD / LiT can be extracted. Once the LiH / LiD / LiT is extracted, the remaining mixture in the liquid phase is a mixture low in Li / LiH / LiD 218 (a second mixture or a fifth mixture).

[0101] The Li / LiH / LiD-depleted mixture 218 can be subjected to deuterium-tritium plasma exposure and / or neutron bombardment 102 to regenerate the Li / LiH / LiD / LiT mixture 104. The reaction can then be restarted with Figure 1B The method described in the relevant Figure 1A Related description methods.

[0102] Figure 1B The temperatures shown in are indicative and may depend on the concentration of lithium hydride in the mixture.

[0103] Figure 2 An embodiment of an apparatus 200 for performing this method is shown. 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 slurry 206, which may be described as a paddle 212; a mechanism for heating or cooling, which may be a serpentine 210, by which the mixture 204 may be heated or cooled using hot or cold water or other fluids. All of this is contained in a container 202, which may be insulated and has holes 214 (openings) in the container 202 for the inclusion and removal of the mixture 204. It should be noted that the ingredients of the mixture 204 may be Figure 1A Any of the mixtures of Li / LiH / LiD / LiT 104, Li / LiH / LiD 118, Li / LiH 128, Li 142, or Figure 1B A mixture 218 having a low content of Li / LiH / LiD in the slurry 206 may be formed from the products of any separation or precipitation step and is effective to achieve extraction of LiT 126, extraction of LiD 138, or extraction of LiH 148.

[0104] Operation Example

[0105] Can be based on Figure 3 The trajectory lines shown complete the operation instructions of the described embodiment of the device. In addition, it is also possible to perform Figure 1A or Figure 1B The method described in .

[0106] The first trajectory 302 occurs when the molar concentration of LiH in the LiH mixture is about 20%. In the first trajectory, at a temperature above about 690°C, the LiH mixture is in an α liquid phase α(l). Along the trajectory 302, if the LiH mixture is cooled, it will enter two phases: an α liquid phase α(l) and a β solid phase β(s). The β solid phase β(s) can be removed and used as Figure 2 The mud 206.

[0107] A second trajectory 304 with a molar concentration of LiH of about 30% may also be used. In this third trajectory 304, at temperatures above about 750°C, the mixture is in an α liquid phase α(l). As the mixture is cooled along trajectory 304, below about 750°C and above about 690°C, the liquid mixture separates into two different liquid phases: αα(l) and ββ(l). If cooling continues to below 690°C, the β liquid phase solidifies to form a β solid phase β(s), which can be removed and used as Figure 2 The mud 206.

[0108] The third trajectory 306 with a LiH molar concentration of about 95% may start from a β liquid phase β(l) at a temperature above 750°C. Along the third trajectory 306, if the mixture is cooled to below 750°C and above 690°C, the α liquid phase and the β liquid phase separate. Furthermore, if the mixture is cooled to below 690°C, the β phase solidifies again to become a β solid phase β(s). The β solid phase β(s) may be removed and used as Figure 2 The mud 206.

[0109] More generally, other trajectories with LiH molar concentrations above 2% or 2.5% and below about 95% may also be used.

[0110] It should be understood that the actual molar concentrations of the compounds in the lithium hydride mixture may be different from the concentrations described herein, and the actual temperature at which the change occurs (transition temperature) may also be different from the temperatures mentioned above. However, it is obvious to those of ordinary skill in the art that the phase separation achieves the same result despite the different conditions.

[0111] For example, it should be understood that the trajectory line 302 represents a LiH molar concentration of approximately 20%. Figure 3 Other vertical trajectories in the same way as in the previous example undergo the same phase transition from the α liquid phase to two different phases (α liquid phase and β solid phase), but occur at other LiH molar concentrations between about 2% or 2.5% and 25%, with the LiH molar concentration of about 25% corresponding to point A of the phase diagram. For any LiH molar concentration in this range, it can be obtained from Figure 3phase diagram or any other Li / LiH phase diagram to determine the corresponding transition temperature.

[0112] Likewise, trajectory line 304 at a LiH molar concentration of about 30% represents another transition from the α liquid phase to two different phases (α liquid phase and β liquid phase) and then to the α liquid phase and β solid phase between LiH molar concentrations of about 25% and 70%. For any LiH molar concentration within this range, the Figure 3 phase diagram or any other Li / LiH phase diagram to determine the corresponding transition temperature.

[0113] Likewise, trajectory line 306 at about 95% LiH molar concentration represents another transition from the β liquid phase to two different phases (α liquid phase and β liquid phase) and then to the α liquid phase and β solid phase between about 70% and 95% LiH molar concentration. For any LiH molar concentration in this range, the transition from Figure 3 phase diagram or any other Li / LiH phase diagram to determine the corresponding transition temperature.

[0114] Figure 4 The Li / LiH and Li / LiD phase diagrams are plotted according to the molar concentration of LiH and LiD, respectively. The molar concentration on the abscissa is a logarithmic scale.

[0115] Figure 4 The Li / LiH and Li / LiD phase diagrams are shown to have similar shapes, but are substantially offset by a few degrees for each concentration. Figure 4 It is shown that the temperature can be manipulated at different molar concentrations to precipitate LiH and LiD, respectively, from a mixture comprising at least Li, LiH and LiD. The transition temperatures for precipitating LiH and LiD, respectively, depend on the molar concentrations of LiH and LiD, respectively, in the mixture.

[0116] In one example, considering that part B of the phase diagram corresponds to a molar concentration below about 25% - the molar concentration corresponding to point A - one can start from a first temperature in the α liquid phase α(l), which corresponds to the region above 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 (β solid phase β(s) of LiD), and then the temperature can be reduced by a few more degrees to a temperature given by the Li / LiH phase diagram to precipitate LiH (β solid phase β(s) of LiH).

[0117] In another example, considering that part C of the phase diagram corresponds to a molar concentration above about 25%, one can start from a first temperature in the α liquid phase α(l) or the α liquid phase and the β liquid phase α(l)+β(l), which corresponds to the area above the two phase diagrams in part C, and then the temperature can be reduced to the temperature given by the Li / LiH phase diagram to precipitate LiH, and then the temperature can be reduced by a few degrees to the temperature given by the Li / LiD phase diagram to precipitate LiD.

[0118] although Figure 4 It is not shown in the figure, but the Li / LiT phase diagram is similar to the Li / LiH and Li / LiD phase diagrams, such as described in "Applied Chemistry of the Alkali Metals" by Hans U. Borgostedt and Cherian K. Mathews, page 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, in part B of the phase diagram, starting from a first temperature in the α liquid phase α(l), the temperature can be reduced to precipitate LiT, then reduced by a few degrees to precipitate LiD, and then reduced by a few degrees to precipitate LiH. In another example, in part C of the phase diagram, starting from a first temperature in the α liquid phase α(l) or the α liquid phase and the β liquid phase α(l)+β(l), the temperature can be reduced to precipitate LiH, then reduced by a few degrees to precipitate LiD, and then reduced by a few degrees to precipitate LiT.

[0119] from Figure 4 It is also apparent that the temperature can be lowered to precipitate LiH / LiD together or LiH / LiD / LiT together.

[0120] More generally, Figure 3 and Figure 4 It is shown that for any concentration of the compound to be separated from Li, for example compounds between 2% and 95% molar concentration, the Li / LiX phase diagram (where X is H, D and / or T) can be used to determine the transition temperature suitable for operating the separation.

[0121] Figure 2 The device shown performs Figure 1A or Figure 1B. The serpentine 210 can be used for the first step of heating 106 or any cooling step: the first step of uniform cooling 110, 210, the second step of uniform cooling 122 or the third step of uniform cooling 136. The agitator 208 can be used for the stirring step: the first step of stirring 108, the second step of stirring 120 or the third step of stirring 134. In addition, the paddle 212 can be used to remove the mud 206, which is the product of the separation and sedimentation steps. The paddle 212 can perform extraction, and the paddle 212 removes the mud 206 through one of the holes 214 in the container, which can be achieved by pushing.

[0122] This summarizes example embodiments of the present invention. Other embodiments are apparent from the entirety of the specification and the claims presented herein.

[0123] Example 1. A method for separating lithium from a lithium mixture, the method comprising:

[0124] Providing a first mixture (104), the first mixture comprising at least a first compound of lithium deuteride and lithium tritide, lithium, and lithium hydride, the first mixture being at a first temperature;

[0125] A first stirring step (108), adapted to stir the first mixture;

[0126] a first cooling step (110; 210) adapted to cool said first mixture to a second temperature lower than said first temperature, preferably uniformly to said second temperature; said first stirring step and said first cooling step adapted to deposit at least a portion of said first compound; and

[0127] A first separation step (116; 216) is suitable for separating at least the deposited first compound from the first mixture, thereby forming a second mixture (118) comprising at least lithium and lithium hydride or a fifth mixture (218) comprising at least lithium.

[0128] Example 2. A method according to Example 1, wherein the first compound is lithium tritiated, the first temperature is above 691°C, and the second temperature is between 689°C and 691°C, for example equal to about 690°C, and the first separation step (116) forms the second mixture (118).

[0129] Example 3. A method according to Example 1, wherein the first stirring step (108) and the first cooling step (210) are suitable for depositing at least a portion of the first compound and at least a portion of the lithium hydride, and the first separation step (116) forms the fifth mixture (218).

[0130] Example 4. A method according to Example 1, wherein the first compound is lithium tritiated, the first mixture (104) further includes lithium deuterated as a second compound, and the first stirring step (108) and the first cooling step (210) are suitable for depositing lithium deuterated and at least a portion of lithium tritiated and at least a portion of lithium hydride to form a fifth mixture (218).

[0131] Example 5. The method according to example 3 or 4, wherein the first temperature is higher than 691°C and the second temperature is between 687°C and 689°C, for example equal to about 688°C.

[0132] Example 6. The method according to any one of Examples 1 to 5 further includes: a first extraction step (126), suitable for extracting one or more deposited compounds after or during the first separation step.

[0133] 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 in some cases repeating the first extraction step.

[0134] Example 8. The method of any one of Examples 1, 2, 6, and 7, wherein the first mixture (104) includes a second compound of lithium deuteride and lithium tritide that is different from the first compound, and the method further includes:

[0135] A second stirring step (120) is suitable for stirring the second mixture;

[0136] a second cooling step (122) adapted to cool the second mixture to a third temperature lower than the second temperature, preferably uniformly to the third temperature; the second stirring step and the second cooling step adapted to deposit at least a portion of the second compound; and

[0137] A second separation step (130) is adapted to separate the precipitated second compound from the second mixture, thereby forming a third mixture (128) comprising at least lithium and lithium hydride.

[0138] Example 9. The method according to Example 8 also includes: a second extraction step (138), suitable for extracting the second compound after or during the second separation step (130).

[0139] Example 10. The method of example 8 or 9, wherein the second compound is lithium deuteride and the third temperature is between 687°C and 689°C, for example equal to about 688°C.

[0140] 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 in some cases repeating the second extraction step.

[0141] Example 12. The method according to any one of Examples 8 to 11, wherein the method further comprises:

[0142] a third stirring step (134), adapted to stir the third mixture (128);

[0143] a third cooling step (136) adapted to cool the third mixture to a fourth temperature lower than the third temperature, preferably uniformly to the fourth temperature; the third stirring step and the third cooling step adapted to deposit at least a portion of the lithium hydride; and

[0144] A third separation step (144) is adapted to separate the deposited lithium hydride from the third mixture, thereby forming a fourth mixture (142) comprising at least lithium.

[0145] Example 13. The method according to Example 12 further includes: a third extraction step (148) suitable for extracting lithium hydride after or during the third separation step (144).

[0146] Example 14. The method according to example 12 or 13, wherein the fourth temperature is between 685°C and 687°C, for example equal to about 686°C.

[0147] Example 15. The method according to any one of Examples 12 to 14, comprising: repeating the third stirring step, the third cooling step and the third separation step, and in some cases repeating the third extraction step.

[0148] Example 16. The method according to any one of Examples 1 to 15, further comprising: a neutron bombardment and / or plasma exposure step (102), wherein the neutron bombardment and / or plasma exposure step (102) is applied to the second mixture (118), the third mixture (128), the fourth mixture (142) and / or the fifth mixture (218), for example to regenerate a mixture similar to the first mixture (104).

[0149] Example 17. A method according to any one of Examples 1 to 16, wherein providing the first mixture (104) includes a heating step (106) suitable for heating the first mixture to the first temperature.

[0150] Example 18. The method according to any one of Examples 1 to 17, wherein the first mixture (104) is in a liquid or molten state.

[0151] Example 19. An apparatus suitable for implementing the method according to any one of Examples 1 to 18, wherein the apparatus comprises:

[0152] A container (202) adapted to contain a mixture (204) comprising at least one compound of lithium deuteride and / or lithium tritide, lithium, and lithium hydride;

[0153] an agitator (208) adapted to agitate the mixture in the container; and

[0154] A cooling mechanism (210) is adapted to cool the mixture in the container.

[0155] Example 20. Apparatus according to Example 19, wherein the cooling mechanism (210) is further adapted to heat the mixture (204), for example the cooling mechanism comprises a serpentine.

[0156] Example 21. An apparatus according to Example 19 or 20, wherein the container includes at least one opening (214) suitable for receiving and removing at least a portion of the mixture.

[0157] Example 22. The apparatus of any one of Examples 19 to 21 further comprises: a removal mechanism (212) adapted to remove at least a portion of the mixture from the container.

[0158] Various embodiments and variations have been described. Those skilled in the art will appreciate that certain features of these embodiments may be combined together, and those skilled in the art will readily conceive of other variations.

[0159] Finally, based on the functional description provided above, actual implementation of the embodiments and variations described herein is within the capabilities of those skilled in the art.

[0160] List of abbreviations:

[0161] LiH: Lithium Hydride

[0162] LiD: Lithium Deuteride

[0163] LiT: Lithium Tritide

[0164] LiCl: Lithium Chloride

[0165] LiF: Lithium Fluoride

[0166] LiBr: lithium bromide

[0167] HCl: hydrochloric acid

[0168] HF: hydrofluoric acid

[0169] HBr: hydrobromic acid

[0170] LiOH: lithium hydroxide

[0171] Li2CO3: Lithium carbonate

[0172] Li: Lithium

Claims

1. A method for separating lithium from a lithium mixture, the method comprising: providing a first mixture (104), the first mixture comprising at least a first compound of lithium deuteride and lithium tritide, lithium, and lithium hydride, the first mixture being at a first temperature; a first stirring step (108), adapted to stir the first mixture; a first cooling step (110; 210) adapted to cool said first mixture to a second temperature lower than said first temperature, preferably uniformly to said second temperature; said first stirring step and said first cooling step adapted to deposit at least a portion of said first compound; a first separation step (116; 216) adapted to separate at least the deposited first compound from the first mixture, thereby forming a second mixture (118; 218) low in at least the first compound; as well as A first extraction step (126; 226) is suitable for extracting the separated first compound after or during the first separation step.

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

3. The method according to claim 1 or 2, wherein: The first temperature is higher than 691°C, and the second temperature is lower than or equal to 691°C.

4. The method according to any one of claims 1 to 3, wherein: The first mixture (104) includes a second compound different from the first compound among lithium deuteride and lithium tritide, and the first stirring step (108) and the first cooling step (210) are suitable for depositing at least a portion of the first compound and the second compound and at least a portion of lithium hydride, and the second mixture (218) has a low content of lithium hydride, lithium deuteride and lithium tritide.

5. The method according to claim 4, wherein: The first temperature is greater than about 691°C, and the second temperature is less than or equal to 687°C.

6. The method according to any one of claims 1 to 3, wherein: The first mixture (104) includes lithium deuteride and a second compound of lithium tritide different from the first compound, and the method further includes: A second stirring step (120), adapted to stir the second mixture (118); a second cooling step (122) adapted to cool the second mixture to a third temperature lower than the second temperature, preferably uniformly to the third 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 (130) adapted to separate the deposited second compound from the second mixture, thereby forming a third mixture (128) having a low content of the first compound and the second compound; and The second extraction step (138) is suitable for extracting the separated second compound after or during the second separation step (130).

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

8. The method according to claim 6 or 7, wherein: The first temperature is higher than 691°C, the second temperature is lower than or equal to 691°C, and the third temperature is lower than or equal to 689°C.

9. The method according to any one of claims 6 to 8, further comprising: a third stirring step (134), adapted to stir the third mixture (128); a third cooling step (136) adapted to cool the third mixture to a fourth temperature lower than the third temperature, preferably uniformly to the fourth 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, thereby forming a fourth mixture (142) having low contents of lithium hydride, lithium deuteride and lithium tritide; as well as The third extraction step (148) is suitable for extracting the separated lithium hydride after or during the third separation step (144).

10. The method according to claim 11, comprising: The third stirring step, the third cooling step, the third separation step and the third extraction step are repeated.

11. The method according to claim 9 or 10, wherein: The first temperature is higher than 691°C, the second temperature is lower than or equal to 691°C, the third temperature is lower than or equal to 689°C, and the fourth temperature is lower than or equal to 687°C.

12. The method according to any one of claims 1 to 11, 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 any one of claims 1 to 12, wherein: The molar concentration of lithium hydride, lithium deuteride and / or lithium tritide in the first mixture is between 2% and 95%, for example between 2.5% and 95%.

14. The method according to any one of claims 1 to 13, wherein: The second temperature, the third temperature and the fourth temperature are all higher than 200°C, for example higher than 210°C.

15. The method according to any one of claims 1 to 14, further comprising: A neutron bombardment and / or plasma exposure step (102) is applied to the second mixture (118; 218), the third mixture (128) and / or the fourth mixture (142), for example to regenerate a mixture similar to the first mixture (104).

16. The method according to any one of claims 1 to 15, wherein: Providing a first mixture (104) comprises a heating step (106), wherein the heating step (106) is adapted to heat the first mixture to the first temperature; and / or The first mixture (104) is in a liquid or molten state.

17. An apparatus suitable for implementing the method according to any one of claims 1 to 16, wherein: The device comprises: A container (202) adapted to contain a mixture (204) comprising at least one compound of lithium deuteride and / or lithium tritide, lithium, and lithium hydride; an agitator (208) adapted to agitate the mixture in the container; and A cooling mechanism (210) is adapted to cool the mixture in the container.

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