A device and method for preparing uranium tetrachloride

Abstract

The present application belongs to the field of nuclear technology, and specifically relates to a device and method for preparing uranium tetrachloride. The device comprises: a CCl4 steam generating unit, a chlorination reaction unit and a tail gas treatment unit; the output end of the CCl4 steam generating unit is connected to the input end of the chlorination reaction unit; the output end of the chlorination reaction unit is connected to the tail gas treatment unit; the CCl4 steam generating unit is used to generate CCl4 steam and output it to the chlorination reaction unit, and the chlorination reaction unit is used to react the CCl4 steam with uranium trioxide to generate UCl4; the tail gas treatment unit is used to collect excess CCl4 steam. In the embodiment of the present application, the gaseous chlorinating agent does not contaminate the solid product, which not only ensures the content of tetravalent uranium in the product, but also realizes stable and rapid preparation, fully considering safety and the recycling of excess reactants, and is also applicable to the preparation of other solid substances with similar reaction principles.

Description

Technical Field

[0001] The present application belongs to the field of nuclear technology, and specifically relates to a device and method for preparing uranium tetrachloride. Background Art

[0002] Uranium tetrachloride (UCl4) is an important uranium halide. As a feedstock for the preparation of nuclear fuel, it has practical application value. It can be used for electromagnetic element separation in the uranium enrichment process. It is also the main raw material for organic uranium chemistry. In addition, because it does not contain hydrogen, carbon, fluorine and other elements, it is very suitable for 1 H. 13 C. 19 The NMR spectrum of F has no interference, and the outer electron of U(Ⅳ) is 5f 2 , similar to Pr(Ⅲ), can form various adducts with Lewis bases, induce shifts in the NMR spectrum of the substrate and be used as a shift reagent.

[0003] At present, the research on the preparation of tetravalent uranium mainly focuses on reducing hexavalent uranium by electrolysis or catalysis to prepare tetravalent uranium in solution, while the preparation process of UCl4 solid is rarely reported. In theory, there are many methods to prepare UCl4, such as preparing it by reacting chlorine-containing gas (such as Cl2, CCl4, SOCl2, etc.) with uranium, uranium hydride or uranium oxide plus carbon mixture at 500-700℃. UCl4 can also be produced by direct combination of metallic uranium and chlorine, but the reaction product is often a complex mixture of various uranium oxidation chlorides, and the chlorides of various valence states are difficult to separate. Therefore, the actual operability of this method is poor, the reaction process is difficult to control and the applicability is not strong, and the yield and safety aspects need to be improved. Summary of the invention

[0004] The purpose of this application is to provide a uranium tetrachloride preparation device and method to solve the problems of poor practical operability, difficult control of the reaction process and low applicability of the existing UCl4 preparation method.

[0005] Technical solution to achieve the purpose of this application:

[0006] In a first aspect, an embodiment of the present application provides a uranium tetrachloride preparation device, the device comprising: a CCl4 steam generation unit, a chlorination reaction unit and a tail gas treatment unit;

[0007] The output end of the CCl4 steam generation unit is connected to the input end of the chlorination reaction unit; the output end of the chlorination reaction unit is connected to the tail gas treatment unit;

[0008] The CCl4 steam generation unit is used to generate CCl4 steam and output it to the chlorination reaction unit, and the chlorination reaction unit is used to react the CCl4 steam with uranium trioxide to generate UCl4; the tail gas treatment unit is used to collect excess CCl4 steam.

[0009] Optionally, the CCl4 steam generating unit comprises: two CCl4 evaporation tanks connected in parallel;

[0010] Liquid CCl4 is input into the liquid inlet of the CCl4 evaporator, and the liquid CCl4 is converted into gas by means of the CCl4 evaporator and pipeline heating, and enters the chlorination reaction unit through the gas outlet and the transmission pipeline.

[0011] Optionally, the CCl4 evaporation tank is provided with a pressure relief valve, a drain valve and a liquid level gauge.

[0012] Optionally, the chlorination reaction unit comprises: a chlorination reactor and a UO3 hopper;

[0013] The air inlet at the upper end of the chlorination reactor is connected to the CCl4 steam generating unit; the upper end of the chlorination reactor is also connected to the lower end of the UO3 hopper through a material pipeline; an auger screw rod is arranged in the material pipeline;

[0014] The interior of the chlorination reactor is provided with multi-layer material flow plates, and a discharge port is opened at the bottom.

[0015] Optionally, one end of each layer of material flow plate is fixed to the inner wall of the chlorination reactor, and the other end is directed toward the middle of the chlorination reactor and tilted downward, and is arranged above the next layer of material flow plate.

[0016] Optionally, a discharge valve is provided at the discharge port.

[0017] Optionally, the tail gas treatment unit specifically includes: a CCl4 cooling trap and a tail gas absorption tank;

[0018] A tail gas outlet is provided on one side of the chlorination reactor, and the tail gas outlet is connected to the upper end of the CCl4 cooling trap through an exhaust pipeline to condense and recover unreacted CCl4;

[0019] The inlet of the tail gas absorption tank is connected to the CCl4 cooling trap for recovering the tail gas.

[0020] Optionally, the reaction temperature of the chlorination reaction unit is 450°C.

[0021] The second aspect of the embodiment of the present application provides a method for preparing uranium tetrachloride, which is applied to any one of the uranium tetrachloride preparation devices provided in the first aspect of the embodiment of the present application; the method comprises:

[0022] Inputting uranium trioxide powder into the chlorination reaction unit;

[0023] Solid CCl4 is input into the CCl4 steam generating unit, and the generated CCl4 steam is output to the chlorination reaction unit to react with uranium trioxide to generate UCl4;

[0024] Collect the UCl4 and excess CCl4 vapor generated by the reaction.

[0025] Optionally, the reaction temperature of the chlorination reaction unit is 450°C.

[0026] The beneficial technical effects of this application are:

[0027] The embodiment of the present application provides a uranium tetrachloride preparation device and method, the device includes: a CCl4 steam generation unit, a chlorination reaction unit and a tail gas treatment unit; the output end of the CCl4 steam generation unit is connected to the input end of the chlorination reaction unit; the output end of the chlorination reaction unit is connected to the tail gas treatment unit; the CCl4 steam generation unit is used to generate CCl4 steam and output it to the chlorination reaction unit, and the chlorination reaction unit is used to react the CCl4 steam with uranium trioxide to generate UCl4; the tail gas treatment unit is used to collect excess CCl4 steam. In the embodiment of the present application, the gaseous chlorinating agent does not contaminate the solid product, enriches the solid UCl4 preparation method, not only ensures the tetravalent uranium content in the product, but also can achieve stable and rapid preparation, fully considers safety and the recycling of excess reactants, and is also applicable to the preparation of other solid substances with similar reaction principles. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a uranium tetrachloride preparation device provided in an embodiment of the present application;

[0029] Figure 2 X-ray diffraction patterns of uranium tetrachloride prepared at different temperatures according to a method for preparing uranium tetrachloride provided in an embodiment of the present application.

[0030] In the figure:

[0031] 1-CCl4 evaporation tank, 2-pressure relief valve, 3-drain valve, 4-liquid level gauge, 5-liquid inlet, 6-gas outlet, 7-chlorination reactor, 8-heating body, 9-CCl4 steam inlet, 10-auger screw, 11-UO3 hopper, 12-material flow plate, 13-exhaust gas outlet, 14-discharge valve, 15-CCl4 cooling trap, 16-exhaust gas absorption tank. DETAILED DESCRIPTION

[0032] In order to make those skilled in the art better understand the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the embodiments described below are only a part of the embodiments of the present application, not all. Based on the embodiments recorded in the present application, all other embodiments obtained by those skilled in the art without paying creative work are within the scope of protection of the present application.

[0033] See also Figure 1 , which is a schematic diagram of the structure of a uranium tetrachloride preparation device provided in an embodiment of the present application.

[0034] A uranium tetrachloride preparation device provided in an embodiment of the present application comprises: a CCl4 steam generation unit, a chlorination reaction unit and a tail gas treatment unit;

[0035] The output end of the CCl4 steam generation unit is connected to the input end of the chlorination reaction unit; the output end of the chlorination reaction unit is connected to the tail gas treatment unit;

[0036] The CCl4 steam generation unit is used to generate CCl4 steam and output it to the chlorination reaction unit, and the chlorination reaction unit is used to react the CCl4 steam with uranium trioxide to generate UCl4; the tail gas treatment unit is used to collect excess CCl4 steam.

[0037] It should be noted that uranium oxides such as uranium octoxide (U3O8), uranium trioxide (UO3) and uranium dioxide (UO2) can react with carbon tetrachloride (CCl4) in the temperature range of 425-475°C to produce UCl4, but in actual production, U3O8 is mostly calcined from slag, chips, etc., and its reaction activity is relatively low, and the UO2 preparation process is relatively complicated. Based on this, the embodiments of the present application select UO3 and CCl4 to react at different temperatures to produce UCl4.

[0038] In a specific example, the reaction temperature of the chlorination reaction unit is 450°C. Figure 2 As shown, UCl4 samples can be obtained within the temperature range of 400-500°C, but there are differences in product purity and reactant conversion rate. The tetravalent uranium content in UCl4 obtained at 450°C is the highest, reaching 58.5%, which is 93.5% of the theoretical value, and the UO3 conversion rate reaches more than 95%.

[0039] In some possible implementations of the embodiments of the present application, the CCl4 steam generation unit may include: two CCl4 evaporation tanks 1 connected in parallel;

[0040] Liquid CCl4 is input into the liquid inlet 5 of the CCl4 evaporation tank 1, and the liquid CCl4 is converted into gas by means of the CCl4 evaporation tank 1 and pipeline heating, and enters the chlorination reaction unit through the gas outlet 6 and the transmission pipeline.

[0041] In one example, a pressure relief valve 2, a drain valve 3 and a liquid level meter 4 are provided on the CCl4 evaporation tank 1.

[0042] In some possible implementations of the embodiments of the present application, the chlorination reaction unit may specifically include: a chlorination reactor 7 and a UO3 hopper 11;

[0043] The air inlet 9 at the upper end of the chlorination reactor 7 is connected to the CCl4 steam generating unit; the upper end of the chlorination reactor 7 is also connected to the lower end of the UO3 hopper 11 through a material pipeline; an auger screw rod 10 is provided in the material pipeline;

[0044] The chlorination reactor 7 is provided with a multi-layer material flow plate 12 inside, and a discharge port is provided at the bottom.

[0045] In one example, one end of each material flow plate 12 is fixed to the inner wall of the chlorination reactor 7 , and the other end is oriented toward the middle of the chlorination reactor 7 and tilted downward, and is disposed above the material flow plate 12 of the next layer.

[0046] In specific implementation, the material falls slowly on the material flow plate 12 due to its own weight and falls to the discharge port (eg, 4 hours), and the reaction is finished.

[0047] In another example, a discharge valve 14 may be provided at the discharge port.

[0048] In some possible implementations of the embodiments of the present application, the tail gas treatment unit may specifically include: a CCl4 cooling trap 15 and a tail gas absorption tank 16;

[0049] A tail gas outlet 13 is provided on one side of the chlorination reactor 7, and the tail gas outlet 13 is connected to the upper end of the CCl4 cooling trap 15 through an exhaust pipe to condense and recover unreacted CCl4;

[0050] The inlet of the tail gas absorption tank 16 is connected to the CCl4 cooling trap 15 for recovering the tail gas.

[0051] The specific use method of the uranium tetrachloride preparation device provided in the embodiment of the present application is described in detail below with reference to a specific example.

[0052] The specific operation steps of a uranium tetrachloride preparation device provided in the embodiment of the present application can be as follows:

[0053] A metering pump is used to inject a certain amount of CCl4 into a CCl4 evaporator 1 with a digital temperature display having a pressure feedback module, a pressure relief valve 2, an emptying valve 3 and a liquid level meter 4. The liquid CCl4 is converted into a gaseous state by means of the CCl4 evaporator and the pipeline heating, and enters the chlorination reactor 7 through the gas outlet 6 of the CCl4 evaporator and the gas inlet 9 of the reactor. Before the gaseous CCl4 is introduced, the UO3 solid powder is pushed from the UO3 hopper 11 to the material flow plate 12 of the chlorination reactor 7 by means of the auger screw 10. The heating temperature of the two-stage heating body 8 of the chlorination reactor 7 is set according to the reaction requirements. After the temperature is raised to the target temperature and stabilized, the gas outlet 6 of the CCl4 evaporator and the gas inlet 9 of the chlorination reactor 7 are opened to continuously introduce CCl4 vapor for chlorination reaction. The material falls slowly on the material flow plate under the influence of its own weight, and falls to the discharge port for about 4 hours, and the reaction is completed. The discharge valve 14 of the chlorination reactor 7 is opened to collect the solid reaction product UCl4, and its tetravalent uranium content and phase structure and other information are analyzed. The remaining CCl4 and other gaseous products of the reaction enter the CCl4 cooling trap 15 through the tail gas outlet 13 with a screen, and the tail gas enters the tail gas absorption tank 16 after condensation and recovery of the unreacted CCl4.

[0054] In the embodiments of the present application, the gaseous chlorinating agent does not contaminate the solid product, enriches the solid UCl4 preparation method, ensures the tetravalent uranium content in the product, and realizes stable and rapid preparation, fully considering the safety and recycling of excess reactants, and is also applicable to the preparation of other solid substances with similar reaction principles.

[0055] Based on the uranium tetrachloride preparation device provided in the above embodiment, the embodiment of the present application further provides a uranium tetrachloride preparation method, which is applied to any one of the uranium tetrachloride preparation devices provided in the above embodiment.

[0056] The present invention provides a method for preparing uranium tetrachloride, comprising:

[0057] Step S101: inputting uranium trioxide powder into the chlorination reaction unit;

[0058] Step S102: solid CCl4 is input into the CCl4 steam generating unit, and the generated CCl4 steam is output to the chlorination reaction unit to react with uranium trioxide to generate UCl4;

[0059] Step S103: collecting UCl4 and excess CCl4 vapor generated by the reaction.

[0060] In one example, the reaction temperature of the chlorination reaction unit is 450°C.

[0061] A method for preparing uranium tetrachloride provided in an embodiment of the present application is described in detail below with reference to a specific example.

[0062] The specific implementation steps of preparing UCl4 solid powder at 450°C using a uranium tetrachloride preparation method provided in the embodiment of the present application are as follows:

[0063] 1) Set the heating temperature of the chlorination reactor to 450°C. After reaching the target temperature and stabilizing, place 500g of UO3 solid powder in the hopper, adjust the speed of the Jiaolong screw to 30rpm / min, and quantitatively push the UO3 solid powder into the chlorination reactor;

[0064] 2) Inject 10L CCl4 into the CCl4 evaporation tank, set its heating temperature to 80°C, and when the evaporator pressure gauge begins to rise, open the solenoid valve to pass CCl4 steam into the chlorination reactor to start the chlorination reaction;

[0065] 3) After the reaction is completed, the reaction mixture is cooled naturally to room temperature, and the discharge valve of the chlorination reactor is opened to collect the solid reaction product UCl4, and its tetravalent uranium content and phase structure are analyzed;

[0066] 4) The remaining CCl4 and other gaseous products from the reaction enter the CCl4 cooling trap through the tail gas outlet with a screen, and the tail gas enters the tail gas absorption tank after condensation and recovery of the unreacted CCl4.

[0067] Theoretically, CCl4 and UO3 react according to the following formula (1). Based on the stoichiometric ratio of reaction formula (1), CCl4 is added in excess as the reaction raw material to prepare the target substance UCl4.

[0068]

[0069] It should be noted that in the reaction, CCl4 needs to be heated and vaporized and pass through a certain pipeline before it can react with UO3. To ensure sufficient reaction, CCl4 should be in excess of 2 times the stoichiometric ratio, that is, according to the chemical reaction dosage ratio, 500g uranium trioxide requires about 1013mL carbon tetrachloride. A 2-fold excess means that about 2026mL carbon tetrachloride needs to be introduced during the reaction.

[0070] The method for preparing uranium tetrachloride provided in the embodiment of the present application has the highest content of tetravalent uranium in UCl4 produced at 450°C, reaching 58.5%, which is 93.5% of the theoretical value, and the UO3 conversion rate reaches more than 95%, enriching the solid UCl4 preparation method. The method is also applicable to the preparation of other solid substances with similar reaction principles.

[0071] The present application is described in detail above in conjunction with the accompanying drawings and embodiments, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present application. Any content not described in detail in the present application can adopt the existing technology.

Claims

1. A uranium tetrachloride preparation device, characterized in that: The device comprises: a CCl4 steam generating unit, a chlorination reaction unit and a tail gas treatment unit; The output end of the CCl4 steam generation unit is connected to the input end of the chlorination reaction unit; the output end of the chlorination reaction unit is connected to the tail gas treatment unit; The CCl4 steam generation unit is used to generate CCl4 steam and output it to the chlorination reaction unit, and the chlorination reaction unit is used to react the CCl4 steam with uranium trioxide to generate UCl4; the tail gas treatment unit is used to collect excess CCl4 steam.

2. The uranium tetrachloride preparation device according to claim 1, characterized in that: The CCl4 steam generating unit comprises: two CCl4 evaporation tanks (1) connected in parallel; Liquid CCl4 is input into the liquid inlet (5) of the CCl4 evaporator (1), and the liquid CCl4 is converted into gas by means of the CCl4 evaporator (1) and pipeline heating, and enters the chlorination reaction unit through the gas outlet (6) and the transmission pipeline.

3. The uranium tetrachloride preparation device according to claim 2, characterized in that: The CCl4 evaporation tank (1) is provided with a pressure relief valve (2), a drain valve (3) and a liquid level meter (4).

4. The uranium tetrachloride preparation device according to claim 1, characterized in that: The chlorination reaction unit comprises: a chlorination reactor (7) and a UO3 hopper (11); The air inlet (9) at the upper end of the chlorination reactor (7) is connected to the CCl4 steam generating unit; the upper end of the chlorination reactor (7) is also connected to the lower end of the UO3 hopper (11) through a material pipeline; an auger screw rod (10) is arranged in the material pipeline; A multi-layer material flow plate (12) is arranged inside the chlorination reactor (7), and a discharge port is opened at the bottom.

5. The uranium tetrachloride preparation device according to claim 4, characterized in that: One end of each material flow plate (12) is fixed to the inner wall of the chlorination reactor (7), and the other end is directed toward the middle of the chlorination reactor (7) and tilted downward, and is arranged above the next material flow plate (12).

6. The uranium tetrachloride preparation device according to claim 4, characterized in that: A discharge valve (14) is provided at the discharge port.

7. The uranium tetrachloride preparation device according to any one of claims 4 to 6, characterized in that: The tail gas treatment unit specifically comprises: a CCl4 cooling trap (15) and a tail gas absorption tank (16); A tail gas outlet (13) is provided on one side of the chlorination reactor (7), and the tail gas outlet (13) is connected to the upper end of the CCl4 cooling trap (15) through an exhaust pipeline to condense and recover unreacted CCl4; The inlet of the tail gas absorption tank (16) is connected to the CCl4 cooling trap (15) for recovering the tail gas.

8. The uranium tetrachloride preparation device according to any one of claims 1 to 6, characterized in that: The reaction temperature of the chlorination reaction unit is 450°C.

9. A method for preparing uranium tetrachloride, characterized in that: The uranium tetrachloride preparation device according to any one of claims 1 to 8; the method comprises: Inputting uranium trioxide powder into the chlorination reaction unit; Solid CCl4 is input into the CCl4 steam generating unit, and the generated CCl4 steam is output to the chlorination reaction unit to react with uranium trioxide to generate UCl4; Collect the UCl4 and excess CCl4 vapor generated by the reaction.

10. The method for preparing uranium tetrachloride according to claim 9, characterized in that: The reaction temperature of the chlorination reaction unit is 450°C.

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