Device and method for preparing uranium hexafluoride based on uranium-containing molten salt
By using chlorine trifluoride as a fluorinating agent to react with uranium-containing molten salt, combined with stirring and separation condensation techniques, the safety hazards and low purity issues in the preparation of uranium hexafluoride from fluorine gas have been resolved, achieving high-purity and economical preparation.
Patent Information
- Application Number
- CN202610107896.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-27
- Publication Date
- 2026-02-27
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing technologies for preparing uranium hexafluoride using fluorine gas present safety hazards, high fluorine gas consumption, low utilization rate, numerous side reactions, and low purity.
Chlorine trifluoride is used as a fluorinating agent to react with uranium dioxide and uranium trioxide in uranium-containing molten salt. Mass transfer efficiency is enhanced by a stirring unit, and unreacted chlorine trifluoride is recovered by a separation unit and a condensation recovery unit. The reaction endpoint is controlled by monitoring the concentration of uranium hexafluoride.
The purity of uranium hexafluoride was improved, the safety hazards and side reaction problems of fluorine gas were solved, the recycling of chlorine trifluoride was realized, and the preparation cost was reduced.
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Figure CN121571081A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application mainly relates to the technical field of molten salt reactor, and particularly relates to a device and method for preparing uranium hexafluoride based on uranium-containing molten salt. BACKGROUND
[0002] With the rapid development of molten salt reactor technology, the preparation method of uranium hexafluoride (UF6) raw material required by the front end of the fuel cycle is a key link in the closed nuclear fuel cycle and has attracted much attention. In the dry reprocessing process of the molten salt reactor, the unburned uranium in the spent fuel needs to be converted and recovered. The preparation of uranium hexafluoride based on spent fuel can realize the reuse of unburned uranium. The traditional wet reprocessing method (such as the PUREX process) has the problems of complex process, generation of a large amount of organic waste liquid and difficulty in directly processing the products of such process.
[0003] At present, the method for preparing UF6 by dry method uses fluorine gas (F2) as a fluorinating agent to react with uranium-containing materials. However, this method has a series of defects: fluorine gas has strong toxicity and oxidizing property, and there are great safety hazards in storage, transportation and operation. The sealing property and corrosion resistance of the reactor and the pipeline system are required to be harsh. Moreover, fluorine gas not only reacts with the target uranium compound, but also reacts violently with various fission products (such as rare earth elements) in the molten salt, resulting in large consumption of fluorine gas, low utilization rate, and generation of more radioactive waste, increasing the burden and cost of subsequent purification of uranium hexafluoride. In addition, when fluorine gas is directly fluorinated into a molten salt system with complex composition, the non-selectivity will lead to uncontrollable reaction and generate various by-products, affecting the stability of the process and the purity of the final product.
[0004] Therefore, how to solve the above problems is one of the hot research directions in the field. SUMMARY
[0005] The technical problem to be solved by the present application is to provide a device and method for preparing uranium hexafluoride based on uranium-containing molten salt, which can improve the purity of the prepared uranium hexafluoride.
[0006] The present application provides a device for preparing uranium hexafluoride based on uranium-containing molten salt, the uranium-containing molten salt containing uranium dioxide and / or triuranium octaoxide, the device comprising: a reaction cavity for containing the uranium-containing molten salt; a gas inlet in communication with the reaction cavity, for introducing fluorinating gas containing chlorotrifluoride into the reaction cavity, the chlorotrifluoride reacting with each of the uranium dioxide and / or the triuranium octaoxide to generate reaction gas containing uranium hexafluoride; a gas outlet in communication with the reaction cavity, for discharging the reaction gas; and a separation unit for separating the uranium hexafluoride from the reaction gas.
[0007] In one embodiment of this application, it further includes: a stirring unit, which is used to stir the uranium-containing molten salt located in the reaction chamber during the process of introducing the fluorinated gas into the uranium-containing molten salt.
[0008] In one embodiment of this application, it further includes a condensation recovery unit for recovering unreacted chlorine trifluoride discharged from the gas outlet.
[0009] In one embodiment of this application, it further includes: a monitoring unit, which is used to monitor the concentration of uranium hexafluoride in the reaction gas discharged from the gas outlet, and control the stopping of the introduction of the fluorinated gas into the uranium-containing molten salt when the concentration of uranium hexafluoride is less than a preset threshold.
[0010] This application also proposes a method for preparing uranium hexafluoride based on uranium-containing molten salt, wherein the uranium-containing molten salt contains uranium dioxide and / or uranium trioxide, and is performed using the apparatus for preparing uranium hexafluoride based on uranium-containing molten salt as described above. The method for preparing uranium hexafluoride based on uranium-containing molten salt includes: introducing a fluorinated gas containing chlorine trifluoride into the uranium-containing molten salt, causing the chlorine trifluoride to react with each of the uranium dioxide and / or the uranium trioxide, the fluorination reaction generating a reaction gas including uranium hexafluoride; and separating the uranium hexafluoride from the reaction gas.
[0011] In one embodiment of this application, the method further includes drying the fluorinated gas before introducing the fluorinated gas containing chlorine trifluoride into the uranium-containing molten salt.
[0012] In one embodiment of this application, the step of introducing a fluorinated gas containing chlorine trifluoride into the uranium-containing molten salt includes: using an inert carrier gas to transport the fluorinated gas, wherein the volume percentage of chlorine trifluoride in the mixture of the fluorinated gas and the inert carrier gas is 20%-50%.
[0013] In one embodiment of this application, the step of separating the uranium hexafluoride from the reaction gas includes: adsorbing the uranium hexafluoride in the reaction gas using an adsorbent; subsequently, desorbing the uranium hexafluoride from the adsorbent and collecting the desorbed uranium hexafluoride.
[0014] In one embodiment of this application, the method further includes: recovering unreacted chlorine trifluoride using a condensation method; and / or absorbing chlorine gas from the reaction gas using an alkaline solution.
[0015] In one embodiment of this application, the method further includes: monitoring the concentration of uranium hexafluoride in the reaction gas, and stopping the introduction of the fluorinated gas into the uranium-containing molten salt when the concentration of uranium hexafluoride is less than a preset threshold.
[0016] In one embodiment of this application, the uranium-containing molten salt is stirred during the process of introducing the fluorinated gas into the uranium-containing molten salt.
[0017] The technical solution of this application has the following technical effects: (1) Compared with the preparation of uranium hexafluoride using fluorine gas in related technologies, this application introduces fluorinating gas containing chlorine trifluoride into uranium-containing molten salt as a fluorinating agent. Chlorine trifluoride can selectively fluorinate uranium oxides in uranium-containing molten salt, thereby improving the purity of the prepared uranium hexafluoride. At the same time, it solves the safety hazards caused by the strong toxicity and strong oxidizing properties of fluorine gas, as well as the problem of low purity of uranium hexafluoride caused by many side reactions during the preparation process using fluorine gas. (2) In the process of preparing uranium hexafluoride, unreacted chlorine trifluoride is condensed and recovered to realize the recycling of chlorine trifluoride, thereby improving the economy of the preparation method. Attached Figure Description
[0018] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings: Figure 1 This is a schematic diagram of the apparatus for preparing uranium hexafluoride based on uranium-containing molten salt according to one embodiment of this application; Figure 2 This is a flowchart of the preparation of uranium hexafluoride using an apparatus based on uranium-containing molten salt in one embodiment of this application; Figure 3 This is a schematic flowchart of a method for preparing uranium hexafluoride based on uranium-containing molten salt according to an embodiment of this application.
[0019] Figure label: Reaction chamber 110 Gas inlet 120 Gas outlet 130 Separation unit 140 Uranium-containing molten salt inlet 150 160 uranium-containing molten salt exports Stirring unit 170 Drying unit 310 Condensation recovery unit 320 Monitoring Unit 330 Alkali absorption unit 340. Detailed Implementation
[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.
[0021] As indicated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.
[0022] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.
[0023] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.
[0024] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0025] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.
[0026] It should be understood that when a component is referred to as "on another component," "connected to another component," "coupled to another component," or "in contact with another component," it can be directly on, connected to, coupled to, or in contact with that other component, or there may be an intervening component. In contrast, when a component is referred to as "directly on another component," "directly connected to," "directly coupled to," or "directly in contact with" another component, there is no intervening component. Similarly, when a first component is referred to as "electrically contacting" or "electrically coupled to" a second component, there is an electrical path between the first and second components that allows current to flow. This electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even if there is no direct contact between the conductive components.
[0027] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.
[0028] The apparatus for preparing uranium hexafluoride based on uranium-containing molten salt (hereinafter referred to as the "preparation apparatus") and the method for preparing uranium hexafluoride based on uranium-containing molten salt (hereinafter referred to as the "preparation method") of this application will be described below through specific embodiments.
[0029] refer to Figure 1 As shown, the preparation apparatus 100 includes a reaction chamber 110, a gas inlet 120 communicating with the reaction chamber 110, a gas outlet 130 communicating with the reaction chamber 110, and a separation unit 140. The reaction chamber 110 is used to contain uranium-containing molten salt and to allow the uranium-containing molten salt to undergo a fluorination reaction with fluorinating gas. The reaction chamber 110 is made of a nickel-based alloy, giving it good resistance to fluoride corrosion and good high-temperature strength and thermal stability at 600℃~650℃. The uranium-containing molten salt inlet 150 is communicating with the reaction chamber 110 and is used to inject uranium-containing molten salt for preparing uranium hexafluoride into the reaction chamber 110. The uranium-containing molten salt outlet 160 is communicating with the reaction chamber 110 and is used to discharge the uranium-containing molten salt after the fluorination reaction from the reaction chamber 110.
[0030] Gas inlet 120 is connected to reaction chamber 110 and is used to introduce fluorinated gas containing chlorine trifluoride into reaction chamber 110. The fluorinated gas reacts with uranium-containing molten salt in reaction chamber 110, and chlorine trifluoride reacts with each of uranium dioxide and / or uranium octaoxide. Gas outlet 130 is connected at one end to reaction chamber 110 and at the other end to separation unit 140. Gas outlet 130 is used to discharge the reaction gas generated in reaction chamber 110 and to introduce the reaction gas into separation unit 140. Separation unit 140 is used to separate uranium hexafluoride from the reaction gas. The preparation apparatus 100 also includes a controller (not shown) that controls gas inlet 120 to introduce fluorinated gas into reaction chamber 110 and controls gas outlet 130 to discharge the reaction gas generated in reaction chamber 110.
[0031] In some embodiments, the reaction chamber 110 further includes a heating unit (not shown) for heating the uranium-containing molten salt inside the reaction chamber 110 to 600°C to 650°C and maintaining that temperature. For example, the heating unit is an induction coil outside the reaction chamber 110, which heats the uranium-containing molten salt by electrical heating.
[0032] In some embodiments, the separation unit 140 includes a sodium fluoride fixed adsorption bed, wherein when the reactant gas passes through the separation unit 140, sodium fluoride selectively adsorbs uranium hexafluoride as an adsorbent; subsequently, the adsorbed saturated sodium fluoride is heated to desorb uranium hexafluoride from the adsorbent; then, the desorbed uranium hexafluoride is collected by condensation in a cold trap to obtain a solid uranium hexafluoride product.
[0033] In some embodiments, the preparation apparatus 100 further includes a stirring unit 170, which stirs the uranium-containing molten salt located in the reaction chamber 110 during the introduction of fluorinated gas into the uranium-containing molten salt. Figure 1 As shown, the stirring unit 170 includes a driver fixed to the reaction chamber 110 and stirring blades extending into the uranium-containing molten salt. During the introduction of fluorinated gas into the uranium-containing molten salt, the driver drives the stirring blades to stir the uranium-containing molten salt located in the reaction chamber 110. Thus, by combining the gas bubbling when fluorinated gas is introduced through the gas inlet 120 with the stirring of the uranium-containing molten salt by the stirring unit 170, the gas-liquid / solid mass transfer efficiency can be enhanced, making the reaction more stable and uniform, and avoiding safety hazards such as local overheating.
[0034] refer to Figure 1 ,as well as Figure 2 The flowchart of the preparation of uranium hexafluoride using an apparatus based on uranium-containing molten salt in one embodiment is shown below.
[0035] First, fluorinated gas containing chlorine trifluoride is passed into drying unit 310 for drying to remove impurities of moisture.
[0036] Subsequently, the controller controls the gas inlet 120 to introduce fluorinated gas into the reaction chamber 110. The dried fluorinated gas enters the reaction chamber 110 through the gas inlet 120 and reacts with the uranium-containing molten salt in the reaction chamber 110 to undergo a fluorination reaction. The controller controls the gas outlet 130 to discharge the reaction gas generated in the reaction chamber 110. The reaction gas enters the separation unit 140 through the gas outlet 130, thereby separating the uranium hexafluoride product.
[0037] In addition to uranium hexafluoride, the gas discharged from gas outlet 130 also includes chlorine, oxygen, and unreacted chlorine trifluoride. The preparation apparatus also includes a condensation and recovery unit 320 for recovering the unreacted chlorine trifluoride discharged from gas outlet 130. Specifically, the condensation and recovery unit 320 is connected to the separation unit 140, cooling the gas discharged from the separation unit 140 to -25°C to condense and recover the unreacted chlorine trifluoride; subsequently, the condensation and recovery unit 320 vaporizes the recovered chlorine trifluoride and re-passes it through the drying unit 310 for recycling, while simultaneously reducing the load on waste treatment.
[0038] Next, refer to Figure 2 As shown, the preparation apparatus also includes an alkaline absorption unit 340, which is connected to the discharge side of the condensation recovery unit 320, for absorbing chlorine gas in the reaction gas and venting the absorbed reaction gas.
[0039] This preparation apparatus realizes the entire process from fluorination reaction, separation of uranium hexafluoride products, recovery of chlorine trifluoride, to purification of reaction gases (such as... Figure 2The complete closed loop of the alkaline absorption unit 340 shown in the figure ultimately discharges clean exhaust gas, achieving good environmental compatibility.
[0040] In one embodiment, such as Figure 1 and Figure 2 As shown, the preparation apparatus also includes a monitoring unit 330 for monitoring the concentration of uranium hexafluoride in the reaction gas discharged from the gas outlet 130. For example, the monitoring unit 330 includes an online mass spectrometer to monitor the concentration of uranium hexafluoride in the reaction gas in real time. When the monitoring unit 330 detects that the concentration of uranium hexafluoride discharged from the gas outlet 130 is less than a preset threshold, the monitoring unit 330 controls the gas inlet 120 to stop supplying fluorinated gas into the reaction chamber 110.
[0041] This application also proposes a preparation method, which is performed using the apparatus described above for preparing uranium hexafluoride based on uranium-containing molten salt. For example... Figure 3 As shown, the preparation method in one embodiment includes steps S101 and S102, which are explained in detail below.
[0042] In step S101, a fluorinated gas containing chlorine trifluoride is introduced into the uranium-containing molten salt, causing the chlorine trifluoride to react with each of uranium dioxide and / or uranium octoxide, and the fluorination reaction generates a reaction gas including uranium hexafluoride.
[0043] The uranium-containing molten salt contains uranium dioxide (UO2) and / or uranium trioxide (U3O8). In some embodiments, the mass fraction of uranium in the uranium-containing molten salt is 1% to 20%. In other embodiments, the uranium-containing molten salt comprises a eutectic salt of fluorides LiF4-BeF4, wherein the molar ratio of LiF4 to BeF4 is approximately 67:33.
[0044] In this step, a fluorinating gas containing chlorine trifluoride (ClF3) is used as the fluorinating agent, and chlorine trifluoride is in a gaseous state at a temperature of 600℃~650℃. Compared with related technologies that use fluorine gas to prepare uranium hexafluoride, chlorine trifluoride can efficiently and selectively fluorinate uranium dioxide and uranium trioxide octaoxide in uranium-containing molten salts, and has very few or no undesirable side reactions with other substances in the molten salt (such as fission products), thereby improving the purity of the fluorination product and reducing radioactive waste. This solves the problem of low uranium hexafluoride purity caused by numerous side reactions in the preparation of uranium hexafluoride using fluorine gas. Furthermore, it also solves the safety hazards caused by the high toxicity and strong oxidizing properties of fluorine gas. At the same time, chlorine trifluoride has the characteristic of easy recycling, which can reduce the preparation cost and thus improve economic efficiency.
[0045] In some embodiments, introducing a fluorinated gas containing chlorine trifluoride into a uranium-containing molten salt includes: using an inert carrier gas to transport the fluorinated gas, wherein the volume percentage of chlorine trifluoride in the mixture of the fluorinated gas and the inert carrier gas is 20% to 50%, and, for example, the inert carrier gas may be argon (Ar).
[0046] Chlorine trifluoride undergoes a fluorination reaction with each of the uranium dioxide and / or uranium trioxide in a uranium-containing molten salt. Specifically, if the uranium-containing molten salt contains uranium dioxide, chlorine trifluoride reacts with it in the following equation: UO₂ + 2ClF₃ → UF₆↑ + O₂↑ + Cl₂↑; if the uranium-containing molten salt contains uranium trioxide, chlorine trifluoride reacts with it in the following equation: U₃O₈ + 8ClF₃ → 3UF₆↑ + 4O₂↑ + 4Cl₂↑; if the uranium-containing molten salt contains both uranium dioxide and uranium trioxide, chlorine trifluoride reacts with both. The reactant gases produced by the fluorination reaction include uranium hexafluoride, oxygen (O₂), and chlorine (Cl₂).
[0047] In some embodiments, prior to the step of introducing fluorinated gas into the uranium-containing molten salt, the fluorinated gas is dried to remove any moisture trapped in it.
[0048] In some embodiments, fluorinated gas is introduced into the uranium-containing molten salt at a gas flow rate of 0.4 L / min to 1 L / min.
[0049] In some embodiments, the uranium-containing molten salt is stirred while fluorinated gas is introduced into it. This enhances gas-liquid / solid mass transfer efficiency and mixing efficiency, resulting in a more stable and uniform reaction.
[0050] In step S102, uranium hexafluoride is separated from the reaction gas.
[0051] In some embodiments, this step includes using an adsorbent to adsorb uranium hexafluoride from the reaction gas, followed by desorption of the uranium hexafluoride from the adsorbent, and collection of the desorbed uranium hexafluoride, as detailed below.
[0052] First, sodium fluoride (NaF) was used as the adsorbent, and the adsorption temperature was set to 120℃. At this adsorption temperature, sodium fluoride selectively adsorbed uranium hexafluoride in the reaction gas, while other gaseous substances in the reaction gas were not adsorbed by sodium fluoride.
[0053] Subsequently, uranium hexafluoride was desorbed from the adsorbent by heating. The desorption temperature was set at 160°C, at which temperature uranium hexafluoride could be released from the adsorbent.
[0054] Finally, the desorbed uranium hexafluoride is collected by condensation in a cold trap at -60°C. At this temperature, the uranium hexafluoride solidifies, yielding a solid uranium hexafluoride product, thus achieving efficient separation of uranium hexafluoride. The sodium fluoride used as the adsorbent can be reused after desorption.
[0055] In some embodiments, the method for preparing uranium hexafluoride based on uranium-containing molten salt further includes: recovering unreacted chlorine trifluoride using a condensation method and / or absorbing chlorine gas in the reaction gas using an alkaline solution. Specifically, the unreacted chlorine trifluoride is still in a gaseous state. This unreacted chlorine trifluoride is recovered by a condensation method, with the condensation temperature set at -25°C, at which temperature the chlorine trifluoride gas liquefies into a liquid state. The recovered chlorine trifluoride liquid is vaporized and then continuously introduced into the uranium-containing molten salt, thereby reducing the consumption of fluorinating agent and raw material costs, and improving the economics of the preparation method. After uranium hexafluoride separation, the reaction gases produced by the fluorination reaction also include chlorine and oxygen. Chlorine is highly toxic. The reaction gases are passed into an alkaline solution, which absorbs the chlorine gas in the reaction gases. Thus, the remaining reaction gases after uranium hexafluoride separation and alkaline absorption can be vented.
[0056] In some embodiments, the alkaline solution is sodium hydroxide (NaOH), and chlorine gas reacts chemically with the alkaline solution. The reaction equation is Cl2 + 2NaOH → NaCl + NaClO + H2O.
[0057] In some other embodiments, the alkaline solution is calcium hydroxide (Ca(OH)2), and chlorine gas reacts chemically with the alkaline solution. The reaction equation is 2Cl2+2Ca(OH)2→Ca(ClO)2+CaCl2+2H2O.
[0058] Furthermore, to optimize process control and improve economic efficiency, in some embodiments, the method for preparing uranium hexafluoride based on uranium-containing molten salt further includes: monitoring the concentration of uranium hexafluoride in the reaction gas, and stopping the introduction of fluorinated gas into the uranium-containing molten salt when the concentration of uranium hexafluoride is less than a preset threshold. The degree of uranium conversion in the uranium-containing molten salt can be determined based on the concentration of uranium hexafluoride in the reaction gas. Therefore, using online monitoring technology to monitor the concentration of uranium hexafluoride in the reaction gas allows for accurate determination of the reaction endpoint and on-demand supply of fluorinating agent, thereby promoting the intelligent and refined preparation method. For example, the online monitoring technology uses an online mass spectrometer to detect the concentration of uranium hexafluoride in the reaction gas. Online monitoring technology is not the focus of this application and will not be elaborated upon here. In some embodiments, the preset threshold is set to 1 ppm; when the concentration of uranium hexafluoride in the reaction gas is less than this preset threshold, the introduction of fluorinated gas into the uranium-containing molten salt is stopped.
[0059] This application uses specific terms to describe embodiments of the application. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.
[0060] It should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the application requires more features than those mentioned. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.
[0061] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used to describe embodiments are sometimes modified by the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in this application are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this application are approximate values, in specific embodiments, such values are set as precisely as feasible.
[0062] Although this application has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, any changes or modifications to the above embodiments within the essential spirit of this application will fall within the scope of the claims of this application.
Claims
1. An apparatus for preparing uranium hexafluoride based on uranium-containing molten salt, wherein the uranium-containing molten salt contains uranium dioxide and / or uranium trioxide, characterized in that, include: A reaction chamber for containing the uranium-containing molten salt; A gas inlet connected to the reaction chamber is used to introduce a fluorinated gas containing chlorine trifluoride into the reaction chamber. The chlorine trifluoride reacts with each of the uranium dioxide and / or the uranium octoxide to produce a reaction gas containing uranium hexafluoride. A gas outlet connected to the reaction chamber is used to discharge the reaction gas; as well as A separation unit is used to separate the uranium hexafluoride from the reaction gas.
2. The apparatus for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 1, characterized in that, Also includes: A stirring unit is provided for stirring the uranium-containing molten salt located in the reaction chamber during the process of introducing the fluorinated gas into the uranium-containing molten salt.
3. The apparatus for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 1, characterized in that, Also includes: A condensation recovery unit is provided for recovering unreacted chlorine trifluoride discharged from the gas outlet.
4. The apparatus for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 1, characterized in that, Also includes: A monitoring unit is provided to monitor the concentration of uranium hexafluoride in the reaction gas discharged from the gas outlet, and to control the cessation of the introduction of the fluorinated gas into the uranium-containing molten salt when the concentration of uranium hexafluoride is less than a preset threshold.
5. A method for preparing uranium hexafluoride based on uranium-containing molten salt, wherein the uranium-containing molten salt contains uranium dioxide and / or uranium trioxide, characterized in that, The method is performed using the apparatus for preparing uranium hexafluoride from uranium-containing molten salt as described in any one of claims 1 to 4, wherein the method comprises: A fluorination gas containing chlorine trifluoride is introduced into the uranium-containing molten salt, causing the chlorine trifluoride to react with each of the uranium dioxide and / or the uranium octoxide, the fluorination reaction producing a reaction gas including uranium hexafluoride; and The uranium hexafluoride is separated from the reaction gas.
6. The method for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 5, characterized in that, Also includes: Before the step of introducing a fluorinated gas containing chlorine trifluoride into the uranium-containing molten salt, the fluorinated gas is dried.
7. The method for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 5, characterized in that, The step of introducing a fluorinated gas containing chlorine trifluoride into the uranium-containing molten salt includes: using an inert carrier gas to transport the fluorinated gas, wherein the volume percentage of chlorine trifluoride in the mixture of the fluorinated gas and the inert carrier gas is 20%-50%.
8. The method for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 5, characterized in that, The steps for separating the uranium hexafluoride from the reaction gas include: Uranium hexafluoride in the reaction gas is adsorbed using an adsorbent. Subsequently, the uranium hexafluoride is desorbed from the adsorbent, and the desorbed uranium hexafluoride is collected.
9. The method for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 5, characterized in that, Also includes: Unreacted chlorine trifluoride was recovered using a condensation method; And / or, use an alkaline solution to absorb chlorine gas from the reaction gas.
10. The method for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 5, characterized in that, Also includes: The concentration of uranium hexafluoride in the reaction gas is monitored, and the fluorinated gas is stopped being introduced into the uranium-containing molten salt when the concentration of uranium hexafluoride is less than a preset threshold.
11. The method for preparing uranium hexafluoride based on uranium-containing molten salt as described in claim 5, characterized in that, The uranium-containing molten salt is stirred while the fluorinated gas is introduced into it.