Atinide carbide fuel and preparation method thereof

Abstract

The invention discloses actinide carbide fuel and a preparation method thereof. The method comprises the following steps: taking actinide oxide or a mixture of actinide oxide and carbon powder as a cathode; when the actinide oxide is used as the cathode, a carbon anode is selected; or when the actinide oxide and carbon powder mixture is used as the cathode, the corresponding anode is selected; and carrying out electrolytic reduction in a molten salt molten state to generate actinide carbides. According to the method, the carbide fuel is prepared according to the principle of a cathode molten salt electro-deoxidation method, oxygen of actinide oxides on a cathode is ionized, ionized oxygen is moved to an anode through molten salt and discharged and removed on the anode, and the carbide fuel is generated on the cathode, and the method has the advantages of being low in reaction temperature, mild in reaction condition, low in critical risk coefficient, simple in operation step, high in yield and the like. The phase and the reaction progress are easy to control, and the product purity and the particle size are controllable.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel preparation, and in particular relates to an actinide carbide fuel and a preparation method thereof. Background Art

[0002] Actinide carbide ceramic nuclear fuels, including UC fuel and (U-Pu)C fuel, have attracted considerable attention due to their fissile nuclides. In addition to their high melting point, isotropic expansion, and excellent irradiation behavior and mechanical properties, these carbide fuels offer unique advantages, including high thermal conductivity, high uranium concentration, and high density. Using these fuels in fast reactors can achieve higher breeding ratios and power densities.

[0003] Carbide fuel is typically produced using the traditional carbothermal reduction method. Actinide oxides and carbon black or graphite powder are mixed in a specific ratio, ground into powder, pressed into blocks, and heated to 1500-1800°C under vacuum or inert gas. Alternatively, it can be produced by reacting actinide metal powder with CH₄ or C₃H₄ at 600-800°C. Carbide fuel can also be produced by arc melting a mixture of actinide oxides and graphite at 2500-2800°C. The resulting carbide fuel can be directly cast or extruded. Other methods have also produced carbide fuel by reacting actinide-containing fluorides directly with CH₄ at temperatures above 1800°C and 0.1 atmosphere pressure. The production of actinide carbides using these methods requires high heating temperatures and consumes significant energy, significantly increasing criticality risk and production costs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an actinide carbide fuel and a preparation method thereof in response to the above-mentioned deficiencies in the prior art. The method utilizes electrolysis to prepare carbide fuel, converting electrical energy into chemical energy, which can save energy, optimize reaction conditions, and reduce criticality risk.

[0005] The technical solution adopted to solve the technical problem of the present invention is to provide a method for preparing actinide carbide fuel, comprising the following steps:

[0006] Actinide oxide, or a mixture of actinide oxide and carbon powder, is used as a cathode;

[0007] When actinide oxide is used as cathode, a carbon anode is selected; or, when a mixture of actinide oxide and carbon powder is used as cathode, a corresponding anode is selected;

[0008] Electrolytic reduction is carried out in the molten salt state to generate actinide carbides.

[0009] Preferably, the method for preparing actinide carbide fuel further comprises the following steps:

[0010] The molten salt is chloride molten salt. Before electrolytic reduction, the chloride molten salt is used as a medium. After being heated to a molten state, an inert anode and an active cathode are inserted for pre-electrolysis to purify the molten salt.

[0011] Preferably, constant voltage electrolysis is adopted, 0V<electrolysis voltage<4V;

[0012] Alternatively, constant current electrolysis is used, 0A<electrolysis current<10A.

[0013] Preferably, the chloride molten salt is one or more of LiCl, NaCl, KCl, CsCl, CaCl2, and MgCl2;

[0014] The inert anode is any one of C rod, Mo rod and W rod;

[0015] The active cathode is Ni foam.

[0016] Preferably, the actinide oxide is An x O y , 1≤x≤5, 1≤y≤10, where An is any one of Ac, Th, Pa, U, Np, Pu, Am, and Cm.

[0017] Preferably, using actinide oxide as cathode specifically comprises the following steps:

[0018] Putting actinide oxide powder into a basket or pressing and sintering actinide oxide powder into tablets and then putting the tablets into a basket as a cathode;

[0019] The process of using a mixture of actinide oxide and carbon powder as a cathode specifically includes the following steps:

[0020] Actinide oxide powder, C powder and a binder are mixed, pressed and sintered, and then placed in a basket, or a mixture of actinide oxide powder and C powder is placed in a basket as a cathode.

[0021] Preferably, when the actinide oxide powder is pressed into a pellet and sintered and then packed into a basket as a cathode, the holding pressure of the pellet is 1-20 MPa, the holding time is 1-30 min, the sintering temperature is 400-1800° C., the heating rate is 1-20° C. / min, the holding time is 1-72 h, and the cooling rate is 1-20° C. / min;

[0022] When actinide oxide powder, C powder and a binder are mixed, pressed and sintered, and then packed in a basket as a cathode, the holding pressure of the tablet is 1-20 MPa, the holding time is 1-30 min, the sintering temperature is 400-1800°C, the heating rate is 1-20°C / min, the holding time is 1-72h, and the cooling rate is 1-20°C / min.

[0023] Preferably, the adhesive is any one or more of polyvinylidene fluoride, polyvinyl alcohol, acryl wax, stearic acid, zinc stearate, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, polyacrylonitrile, and polyacrylate.

[0024] Preferably, when the actinide oxide powder, C powder and binder are mixed, pressed and sintered and then packed into a basket, the mass ratio of the actinide oxide powder, C powder and binder is (0.1-10): (0.1-10): (0.1-1);

[0025] Alternatively, when the actinide oxide powder and the C powder are put into a basket, the mass ratio of the actinide oxide powder to the C powder is (0.1-10):(0.1-10).

[0026] Preferably, the corresponding anode is any one of Pt, Mo, W, ceramic, and carbon anode.

[0027] Preferably, the system in which the electrolytic reduction process occurs is a three-electrode system, and a corresponding solid reference electrode is selected, which is any one of Ag / AgCl, LiPb, Ni wire, Mo wire, and Pt wire.

[0028] Preferably, during electrolytic reduction, constant voltage electrolysis is adopted, wherein -4V≤electrolysis voltage<0V;

[0029] Alternatively, constant current electrolysis is used, 0A<electrolysis current≤10A.

[0030] Preferably, the electrolytic reduction further comprises the following steps:

[0031] Actinide carbides are generated at the cathode, the products are removed from the molten salt, and then transferred to a vacuum distillation apparatus for vacuum distillation to remove the adhering molten salt or the molten salt is removed by a solvent washing method.

[0032] Preferably, the temperature of the electrolytic reduction is 550-1000°C.

[0033] The present invention also provides an actinide carbide fuel, which is prepared by the above method.

[0034] The UC fuel prepared in the present invention has a particle size of 0.1-20 microns and a purity of more than 98%.

[0035] The present invention adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of the present invention is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. The new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the process technology for electrolyzing actinide oxides to prepare actinide carbide fuel in Examples 2-5 of the present invention;

[0037] Figure 2 Schematic diagram of the process technology after the electrolysis of actinide oxides in Examples 2-5 of the present invention is completed;

[0038] Figure 3 Schematic diagram of the process technology for electrolyzing actinide oxides to prepare actinide carbide fuel in Examples 6-9 of the present invention;

[0039] Figure 4 It is a schematic diagram of the process technology after the electrolysis of actinide oxides in Examples 6-9 of the present invention is completed.

[0040] In the figure: 1-anode, 2-electrolytic cell, 3-wire, 4-molten salt medium, 5-cathode basket, 6-reactant, 7-reference electrode, 8-product. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0042] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0043] Example 1

[0044] This embodiment provides a method for preparing actinide carbide fuel, comprising the following steps:

[0045] Actinide oxide, or a mixture of actinide oxide and carbon powder, is used as a cathode;

[0046] When actinide oxide is used as cathode, a carbon anode is selected; or, when a mixture of actinide oxide and carbon powder is used as cathode, a corresponding anode is selected;

[0047] Electrolytic reduction is carried out in the molten salt state to generate actinide carbides.

[0048] This embodiment also provides an actinide carbide fuel, which is prepared by the above method.

[0049] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0050] Example 2

[0051] This embodiment provides a method for preparing actinide carbide fuel, comprising the following steps:

[0052] Actinide oxide, or a mixture of actinide oxide and carbon powder, is used as a cathode;

[0053] When actinide oxide is used as cathode, a carbon anode is selected; or, when a mixture of actinide oxide and carbon powder is used as cathode, a corresponding anode is selected;

[0054] Electrolytic reduction is carried out in the molten salt state to generate actinide carbides.

[0055] Preferably, the method for preparing actinide carbide fuel further comprises the following steps:

[0056] The molten salt is chloride molten salt. Before electrolytic reduction, the chloride molten salt is used as a medium. After being heated to a molten state, an inert anode and an active cathode are inserted for pre-electrolysis to purify the molten salt.

[0057] Preferably, during pre-electrolysis, constant voltage electrolysis is adopted, 0V<electrolysis voltage<4V;

[0058] Alternatively, constant current electrolysis is used, 0A<electrolysis current<10A.

[0059] Preferably, the chloride molten salt is one or more of LiCl, NaCl, KCl, CsCl, CaCl2, and MgCl2;

[0060] The inert anode is any one of C rod, Mo rod and W rod;

[0061] The active cathode is Ni foam.

[0062] Preferably, the actinide oxide is An x O y , 1≤x≤5, 1≤y≤10, where An is any one of Ac, Th, Pa, U, Np, Pu, Am, and Cm.

[0063] Preferably, using actinide oxide as cathode specifically comprises the following steps:

[0064] Putting actinide oxide powder into a basket or pressing and sintering actinide oxide powder into tablets and then putting the tablets into a basket as a cathode;

[0065] The process of using a mixture of actinide oxide and carbon powder as a cathode specifically includes the following steps:

[0066] Actinide oxide powder, C powder and a binder are mixed, pressed and sintered, and then placed in a basket, or a mixture of actinide oxide powder and C powder is placed in a basket as a cathode.

[0067] Preferably, when the actinide oxide powder is pressed into a pellet and sintered and then packed into a basket as a cathode, the holding pressure of the pellet is 1-20 MPa, the holding time is 1-30 min, the sintering temperature is 400-1800° C., the heating rate is 1-20° C. / min, the holding time is 1-72 h, and the cooling rate is 1-20° C. / min;

[0068] When actinide oxide powder, C powder and a binder are mixed, pressed and sintered, and then packed in a basket as a cathode, the holding pressure of the tablet is 1-20 MPa, the holding time is 1-30 min, the sintering temperature is 400-1800°C, the heating rate is 1-20°C / min, the holding time is 1-72h, and the cooling rate is 1-20°C / min.

[0069] Preferably, the adhesive is any one or more of polyvinylidene fluoride, polyvinyl alcohol, acryl wax, stearic acid, zinc stearate, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, polyacrylonitrile, and polyacrylate.

[0070] Preferably, when the actinide oxide powder, C powder and binder are mixed, pressed and sintered and then packed into a basket, the mass ratio of the actinide oxide powder, C powder and binder is (0.1-10): (0.1-10): (0.1-1);

[0071] Alternatively, when the actinide oxide powder and the C powder are put into a basket, the mass ratio of the actinide oxide powder to the C powder is (0.1-10):(0.1-10).

[0072] Preferably, the corresponding anode is any one of Pt, Mo, W, ceramic, and carbon anode.

[0073] Preferably, the system in which the electrolytic reduction process occurs is a three-electrode system, and a corresponding solid reference electrode is selected, which is any one of Ag / AgCl, LiPb, Ni wire, Mo wire, and Pt wire.

[0074] Preferably, during electrolytic reduction, constant voltage electrolysis is adopted, wherein -4V≤electrolysis voltage<0V;

[0075] Alternatively, constant current electrolysis is used, 0A<electrolysis current≤10A.

[0076] Preferably, the electrolytic reduction further comprises the following steps:

[0077] Actinide carbides are generated at the cathode, the products are removed from the molten salt, and then transferred to a vacuum distillation apparatus for vacuum distillation to remove the adhering molten salt or the molten salt is removed by a solvent washing method.

[0078] Preferably, the temperature of the electrolytic reduction is 550-1000°C.

[0079] This embodiment also provides an actinide carbide fuel, which is prepared by the above method.

[0080] Specifically, such as Figure 1 and 2 As shown, this embodiment provides a process technology for electrolyzing actinide oxides for preparing actinide carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and voltage (current), and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8 as an example, the specific process flow for preparing UC fuel is as follows:

[0081] S1 Pretreatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) into electrolytic cell 2 and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a voltage of 0.1V to purify the molten salt.

[0082] S2 integrated cathode preparation: Weigh 0.2g of U3O8 powder as reactant 6 and directly put it into the cathode basket 5 after compaction. Then install the conductive wire 3 at the top of the cathode basket as an integrated cathode.

[0083] S3 electrolysis of U3O8: A two-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction molten salt medium 4. The basketed U3O8 powder obtained in S2 was used as the cathode, and C was selected as the anode 1. Then, a suitable voltage (-2.1V) was applied to the molten state for constant voltage electrolysis for 48 hours. The electrolytic reduction temperature was 550°C until the U3O8 was completely converted into carbide, obtaining product 8.

[0084] S4 purifies the product: After the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and transferred to a vacuum distillation device for vacuum distillation to remove the molten salt on the surface of the UC product and the mixed molten salt. Alternatively, a solvent (such as ethanol) washing method can be used to remove the molten salt to obtain pure UC for storage and standby use.

[0085] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.1%.

[0086] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides, mainly involving solid cathode molten salt electro-deoxidation technology. The key to this embodiment is to select appropriate cathode, anode, reference electrode and voltage (current) for electrolysis, and apply a higher voltage (current) than An in the molten state. x O y -C or An x O y The carbide fuel is prepared by electro-deoxidation at a melting voltage lower than the voltage at which the working molten salt decomposes. Compared with the traditional carbothermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of the actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, where it is discharged and removed, and a new method is used to generate carbide fuel at the cathode. Compared with the traditional carbothermal reduction reaction preparation technology, this method has the advantages of low reaction temperature, mild reaction conditions, low critical risk factor, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0087] Example 3

[0088] like Figure 1 and 2 As shown, this embodiment provides a process technology for electrolyzing actinide oxides for preparing actinide carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and currents, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8 as an example, the specific process flow for preparing UC fuel is described below, which differs from the method in Example 2 in that:

[0089] S1: Pre-treatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) into electrolytic cell 2 and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a voltage of 2V to purify the molten salt.

[0090] Preparation of S2 integrated cathode: 0.2 g of U3O8 powder was weighed and mixed with 0.5 wt% ak wax binder (AKL), and then pressed and sintered in air to form a chip. The holding pressure of the tablet was 1 MPa, the holding time was 1 min, the sintering temperature was 400°C, the heating rate was 10°C / min, the holding time was 72 h, and the cooling rate was 10°C / min. The chip was then loaded into the cathode basket 5 as a reactant 6, and a conductive wire 3 was installed at the upper end of the cathode basket as an integrated cathode.

[0091] S3 electrolysis of U3O8: A two-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction molten salt medium 4. The basketed U3O8 obtained in S2 was used as the cathode, and C was selected as the anode 1. Then, a suitable voltage (-2.1V) was applied to the molten state for constant voltage electrolysis for 48 hours. The electrolytic reduction temperature was 1000°C until the U3O8 was completely converted into carbide, obtaining product 8.

[0092] S4 purifies the product: After the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and transferred to a vacuum distillation device for vacuum distillation to remove the molten salt on the surface of the UC product and the mixed molten salt. Alternatively, a solvent (such as ethanol) washing method can be used to remove the molten salt to obtain pure UC for storage and standby use.

[0093] Specifically, the anode for pre-electrolysis purification of the molten salt medium in Examples 1 and 2 may be an inert electrode, including but not limited to a graphite rod, a Pt wire, or a Mo wire.

[0094] In Examples 1 and 2, the cathode for pre-electrolysis purification of the molten salt medium may be an active electrode, including but not limited to foamed Ni.

[0095] The anode for the electrolysis of actinide oxide reactants in Examples 1 and 2 can be a carbon-containing electrode rod, including but not limited to carbon black, graphite rod, and composite graphite rod.

[0096] The cathode of the electrolytic actinide oxide reactant in Examples 1 and 2 can be actinide oxide, including but not limited to Ac x O y Th x O y 、Pa x O y 、U x O y 、Np x Oy 、Pu x O y 、Am x O y 、Cm x O y wait.

[0097] An x O y The state of the precipitate can be solid powder or solid pellet.

[0098] The chloride molten salt in Examples 1 and 2 may be, but is not limited to, the following compounds: LiCl, NaCl, KCl, CsCl, CaCl2, and MgCl2 may be one of the molten salts or a mixture of two or more molten salts.

[0099] In this embodiment 2, the binder includes but is not limited to polyvinylidene fluoride, polyvinyl alcohol, AKL wax (AKL), stearic acid, zinc stearate, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, polyacrylonitrile and polyacrylate.

[0100] In this embodiment 2, during the constant voltage electrolysis process, the voltage is set to -4V to 0V.

[0101] In this embodiment 3, during the constant current electrolysis process, the current is set to 0A to 10A.

[0102] This embodiment also provides a UC fuel, which is prepared by the above method.

[0103] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.5%.

[0104] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0105] Example 4

[0106] like Figure 1 and 2As shown, this embodiment provides a process technology for electrolyzing actinide oxide-C for preparing actinide carbide fuel. The key to this process is to pre-treat and purify the molten salt medium, prepare an integrated cathode, select suitable electrodes, potential (or current), and purify the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8-C as an example, the specific process flow for preparing UC fuel is described as follows, which differs from the method in Example 2 as follows:

[0107] S1: Pre-treatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) into electrolytic cell 2 and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a voltage of 3.9V to purify the molten salt.

[0108] Preparation of S2 integrated cathode: Weigh 1.0g of U3O8 powder and C powder, mix them and directly load them into the stainless steel cathode basket 5 as reactant 6, and then install the conductive wire 3 on the upper end of the basket as the integrated cathode;

[0109] S3 electrolysis of U3O8-C powder: A two-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction molten salt medium 4. The basketed U3O8-C powder obtained in S2 was used as the cathode, and C was selected as the anode 1. Then, a suitable voltage (-2.1V) was applied in the molten state for constant voltage electrolysis for 48 hours. The electrolytic reduction temperature was 800°C until the U3O8 was completely converted into carbide, obtaining product 8.

[0110] S4 purifies the product: after the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the UC product and the mixed molten salt, thereby obtaining pure UC for storage.

[0111] This embodiment also provides a UC fuel, which is prepared by the above method.

[0112] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.3%.

[0113] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0114] Example 5

[0115] like Figure 1 and 2 As shown, this embodiment provides a process technology for electrolyzing actinide oxide-C for preparing actinide carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and currents, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8-C as an example, the specific process flow for preparing UC fuel is described below, which differs from the method in Example 2 in that:

[0116] S1: Pre-treatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) into electrolytic cell 2 and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a current of 0.1A to purify the molten salt.

[0117] Preparation of S2 integrated cathode: 1g of U3O8 powder, 0.05g of C powder and 0.5wt% of AKL binder (AKL) were weighed and mixed, and then pressed and sintered into chips in argon. The holding pressure of the tablet was 10Mpa, the holding time was 30min, the sintering temperature was 900℃, the heating rate was 1℃ / min, the holding time was 36h, and the cooling rate was 20℃ / min. The chip was then loaded into the cathode basket 5 as the reactant 6, and the conductive wire 3 was installed at the upper end of the basket as the integrated cathode;

[0118] S3 Electrolysis of U3O8-C: A two-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction molten salt medium 4. The basketed U3O8-C chip obtained in S2 was used as the cathode, and C was selected as the anode 1. Constant-potential electrolysis was then performed in the molten state with an appropriate voltage (-2.1 V) for 48 hours at a temperature of 700°C until the U3O8 was completely converted to carbide, yielding product 8.

[0119] S4 purifies the product: after the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the UC product and the mixed molten salt, thereby obtaining pure UC for storage.

[0120] Specifically, the anode for pre-electrolysis purification of the molten salt medium in Examples 3 and 4 may be an inert electrode, including but not limited to a graphite rod, a Pt wire, or a Mo wire.

[0121] In Examples 4 and 5, the cathode for pre-electrolysis purification of the molten salt medium may be an active electrode, including but not limited to foamed Ni.

[0122] The anode for the electrolysis of actinide oxide-C reactants in Examples 4 and 5 can be a carbon-containing electrode rod, including but not limited to Pt, Mo, W, ceramics, carbon black, graphite rod, and composite graphite rod.

[0123] The cathode of the electrolytic actinide oxide-C reactant in Examples 4 and 5 can be actinide oxide, including but not limited to Ac x O y Th x O y 、Pa x O y 、U x O y 、Np x O y 、Pu x O y 、Am x O y 、Cm x O y wait.

[0124] An x O y The state of the precipitate can be solid powder or solid pellet.

[0125] The chloride molten salt in Examples 4 and 5 may be, but is not limited to, the following compounds: LiCl, NaCl, KCl, CsCl, CaCl2, and MgCl2 may be one of the molten salts or a mixture of two or more molten salts.

[0126] In this embodiment 4, during the constant voltage electrolysis process, the electrolysis voltage is set to -4V to 0V.

[0127] In this embodiment 5, during the constant current electrolysis process, the current is set to 0A to 10A.

[0128] The binder in this embodiment 5 includes but is not limited to polyvinylidene fluoride, polyvinyl alcohol, AKL wax (AKL), stearic acid, zinc stearate, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, polyacrylonitrile and polyacrylate.

[0129] This embodiment also provides a UC fuel, which is prepared by the above method.

[0130] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.8%.

[0131] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0132] Example 6

[0133] like Figure 3 and 4 As shown, this embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8 as an example, the specific process flow for preparing UC fuel is described below, which differs from the method in Example 2 in that:

[0134] S1: Pre-treatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) into electrolytic cell 2 and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a current of 5A to purify the molten salt.

[0135] Preparation of S2 integrated cathode: Weigh 0.2g of U3O8 powder as feed material and directly put it into the stainless steel cathode basket 5 for compaction. Then install the conductive wire 3 on the upper end of the cathode basket to serve as the integrated cathode.

[0136] S3 Electrolysis of U3O8: A three-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction molten salt medium 4. The basketed U3O8 powder obtained in S2 was used as the cathode, C was selected as the anode 1, and Ag / AgCl was used as the reference electrode 7. Then, a suitable voltage (-2.1V) was applied in the molten state for constant voltage electrolysis for 48 hours. The electrolytic reduction temperature was 600°C, until the U3O8 was completely converted to carbide, obtaining product 8.

[0137] S4 purifies the product: after the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the UC product and the mixed molten salt, thereby obtaining pure UC for storage.

[0138] This embodiment also provides a UC fuel, which is prepared by the above method.

[0139] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.2%.

[0140] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0141] Example 7

[0142] like Figure 3 and 4 As shown, this embodiment provides a process technology for electrolyzing actinide oxide-C for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and currents, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8 as an example, the specific process flow for preparing UC fuel is described below, which differs from the method in Example 2 in that:

[0143] S1: Pre-treatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) into electrolytic cell 2 and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a current of 9.9A to purify the molten salt.

[0144] Preparation of S2 integrated cathode: 0.2 g of U3O8 powder was weighed and mixed with 0.5 wt% AKL binder, and then pressed and sintered in air to form a chip. The holding pressure of the tablet was 10 MPa, the holding time was 30 min, the sintering temperature was 900°C, the heating rate was 1°C / min, the holding time was 36 h, and the cooling rate was 20°C / min. The chip was then loaded into the cathode basket 5 as a reactant 6, and a conductive wire 3 was installed at the upper end of the cathode basket as an integrated cathode.

[0145] Electrolysis of U3O8 in S3: A three-electrode system was used, with the purified LiCl molten salt obtained in S1 serving as the reaction molten salt medium 4. The basketed U3O8 pellets obtained in S2 were used as the cathode, C was selected as the anode 1, and Ag / AgCl was used as the reference electrode 7. Constant-potential electrolysis was then performed in the molten state with an appropriate voltage (-2.1 V) for 48 h at a temperature of 800°C until the U3O8 was completely converted to carbide, yielding product 8.

[0146] S4 purifies the product: after the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the UC product and the mixed molten salt, thereby obtaining pure UC for storage.

[0147] Specifically, the anode for pre-electrolysis purification of the molten salt medium in Examples 6 and 7 may be an inert electrode, including but not limited to a graphite rod, a Pt wire, or a Mo wire.

[0148] In Examples 6 and 7, the cathode for pre-electrolysis purification of the molten salt medium may be an active electrode, including but not limited to foamed Ni.

[0149] The anode for the electrolysis of actinide oxide reactants in Examples 6 and 7 can be a carbon-containing electrode rod, including but not limited to carbon black, graphite rod, and composite graphite rod.

[0150] The cathode of the electrolysis of actinide oxides in Examples 6 and 7 can be actinide oxides, including but not limited to Ac x O y Th x O y 、Pa x O y 、U x O y 、Np x O y 、Pu x O y 、Am x O y 、Cm x O y wait.

[0151] An x O y The state of the precipitate can be solid powder or solid pellet.

[0152] The reference electrode for the electrolysis of actinide oxide reactants in Examples 6 and 7 is a solid reference electrode, including but not limited to Ag / AgCl, LiPb, Ni wire, Mo wire, Pt wire, etc.

[0153] The chloride molten salt in Examples 6 and 7 may be, but is not limited to, the following compounds: LiCl, NaCl, KCl, CsCl, CaCl2, and MgCl2 may be one of the molten salts or a mixture of two or more molten salts.

[0154] In this embodiment 6, during the constant voltage electrolysis process, the electrolysis voltage is set to -4V to 0V.

[0155] In this embodiment 7, during the constant current electrolysis process, the current is set to 0A to 10A.

[0156] The binder in this embodiment 7 includes but is not limited to polyvinylidene fluoride, polyvinyl alcohol, AKL wax (AKL), stearic acid, zinc stearate, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, polyacrylonitrile and polyacrylate.

[0157] This embodiment also provides a UC fuel, which is prepared by the above method.

[0158] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.5%.

[0159] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0160] Example 8

[0161] like Figure 3 and 4As shown, this embodiment provides a process technology for electrolyzing actinide oxide-C for preparing carbide fuel. The key to this process is to pre-treat and purify the molten salt medium, prepare an integrated cathode, select suitable electrodes, voltage (or current), reference electrodes, and purify the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8 as an example, the specific process flow for preparing UC fuel is described as follows, which differs from the method in Example 2 as follows:

[0162] S1: Pre-treatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) into electrolytic cell 2 and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a voltage of 2V to purify the molten salt.

[0163] Preparation of S2 integrated cathode: 1.0 g of U3O8 powder and 0.05 g of C powder were weighed as reactants 6, mixed and directly placed into a stainless steel cathode basket 5 for compaction. Then, a conductive wire 3 was installed on the upper end of the cathode basket to serve as an integrated cathode.

[0164] S3 Electrolysis of U3O8-C: A three-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction molten salt medium 4. The basketed U3O8 powder obtained in S2 was used as the cathode, C was selected as the anode 1, and Ag / AgCl was used as the reference electrode 7. Then, a suitable voltage (-2.1V) was applied to the molten state for constant voltage electrolysis for 48 hours at a temperature of 1000°C until the U3O8 was completely converted to carbide, obtaining product 8.

[0165] S4 purifies the product: after the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the UC product and the mixed molten salt, thereby obtaining pure UC for storage.

[0166] This embodiment also provides a UC fuel, which is prepared by the above method.

[0167] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.2%.

[0168] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0169] Example 9

[0170] like Figure 3 and 4 As shown, this embodiment provides a process technology for electrolyzing actinide oxide-C for preparing carbide fuel. The key to this process is to pre-treat and purify the molten salt medium, prepare an integrated cathode, select suitable electrodes, voltage (or current), reference electrodes, and purify the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking U3O8 as an example, the specific process flow for preparing UC fuel is described as follows, which differs from the method in Example 2 as follows:

[0171] S1 Pretreatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (LiCl) and add it to electrolytic cell 2, then heat it to a molten state. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a current of 3A to purify the molten salt.

[0172] Preparation of S2 integrated cathode: 1.0 g of U3O8, 0.05 g of C and 0.5 wt% of AKL binder (AKL) were weighed and mixed, and then pressed and sintered. The holding pressure of the pressed tablet was 20 MPa, the holding time was 15 min, the sintering temperature was 1800 ° C, the heating rate was 20 ° C / min, the holding time was 1 h, and the cooling rate was 1 ° C / min. The sintered pressed tablet was then directly loaded into the cathode basket 5 as the reactant 6 for basket loading, and then the conductive wire 3 was installed at the upper end of the cathode basket as an integrated cathode;

[0173] S3 Electrolysis of U3O8: A three-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction molten salt medium 4. The basketed U3O8 powder obtained in S2 was used as the cathode, C was selected as the anode 1, and Ag / AgCl was used as the reference electrode 7. Then, a suitable voltage (-2.1V) was applied to the molten state for constant voltage electrolysis for 48 hours. The electrolytic reduction temperature was 550°C until the U3O8 was completely converted to carbide, obtaining product 8.

[0174] S4 purifies the product: after the electrolysis is completed, the UC product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the UC product and the mixed molten salt, thereby obtaining pure UC for storage.

[0175] Specifically, the anode for pre-electrolysis purification of the molten salt medium in Examples 8 and 9 may be an inert electrode, including but not limited to a graphite rod, a Pt wire, or a Mo wire.

[0176] In Examples 8 and 9, the cathode for pre-electrolysis purification of the molten salt medium may be an active electrode, including but not limited to foamed Ni.

[0177] The anode for the electrolysis of actinide oxide-C reactants in Examples 8 and 9 can be a carbon-containing electrode rod, including but not limited to Pt, Mo, W, ceramics, carbon black, graphite rod, and composite graphite rod.

[0178] In Examples 8 and 9, the cathode of the reactant for electrolyzing actinide oxides may be an actinide oxide, including but not limited to Ac x O y Th x O y 、Pa x O y 、U x O y 、Np x O y 、Pu x O y 、Am x O y 、Cm x O y wait.

[0179] An x O y The state of the precipitate can be solid powder or solid pellet.

[0180] The reference electrode for the electrolysis of actinide oxide reactants in Examples 8 and 9 is a solid reference electrode, including but not limited to Ag / AgCl, LiPb, Ni wire, Mo wire, Pt wire, etc.

[0181] The chloride molten salt in Examples 8 and 9 may be, but is not limited to, the following compounds: LiCl, NaCl, KCl, CsCl, CaCl2, and MgCl2 may be one of the molten salts or a mixture of two or more molten salts.

[0182] In this embodiment 8, during the constant voltage electrolysis process, the electrolysis voltage is set to -4V to 0V.

[0183] In this embodiment 9, during the constant current electrolysis process, the current is set to 0A to 10A.

[0184] The binder in this embodiment 9 includes but is not limited to polyvinylidene fluoride, polyvinyl alcohol, AKL wax (AKL), stearic acid, zinc stearate, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, polyacrylonitrile and polyacrylate.

[0185] This embodiment also provides a UC fuel, which is prepared by the above method.

[0186] The UC fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.3%.

[0187] The advantages of the process technology used in this embodiment for electrolyzing actinide oxides to prepare actinide carbide fuel are: (1) the principle and operation steps of the electro-deoxidation preparation process are simple, which saves operation time; (2) compared with the traditional carbon thermal reaction preparation process, the reaction temperature of this process is lower, which can reduce the critical risk; (3) the reaction progress is controllable; (4) An x C y The purity and particle size are controllable.

[0188] Example 10

[0189] This embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking actinium oxide as an example, the specific process flow for preparing actinide carbide fuel is described below, which differs from the method in Example 2 in that:

[0190] S1 Integrated cathode preparation: Weigh 0.2 g of actinium oxide powder and place it directly into a stainless steel basket for compaction. Then, install a conductive wire on the top of the basket to serve as the integrated cathode.

[0191] S2 electrolysis of actinium oxide: A three-electrode system was used with molten LiCl as the reaction medium. The basketed actinium oxide powder obtained in S2 was used as the cathode, C was selected as the anode, and Ag / AgCl was used as the reference electrode. A suitable voltage (-2.1V) was then applied in the molten state for 48 hours of constant voltage electrolysis. The electrolytic reduction temperature was 600°C until the actinium oxide was completely converted to carbide.

[0192] S3 purifies the product: after the electrolysis is completed, the actinide carbide product obtained in S2 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the actinide carbide product and the mixed molten salt, thereby obtaining pure actinide for storage.

[0193] This embodiment also provides an actinium carbide fuel, which is prepared by the above method.

[0194] The particle size of the actinide carbide fuel prepared in this embodiment is 0.1-20 microns, and the purity is 98.7%.

[0195] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0196] Example 11

[0197] This embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking thorium oxide as an example, the specific process flow for preparing thorium carbide fuel is described below, which differs from the method in Example 2 in the following ways:

[0198] S1 molten salt medium pretreatment purification: weigh 50g of chloride molten salt (NaCl, KCl, the mass ratio of the two is 1:1) and add it to the electrolytic cell, then heat it to a molten state. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis.

[0199] The pre-electrolysis voltage is 0.1 V to purify the molten salt;

[0200] Preparation of S2 integrated cathode: Weigh 0.2g of thorium oxide powder and mix it with 0.5wt% zinc stearate, then press and sinter it in air to form a chip. The tableting pressure is 15MPa, the pressure holding time is 10min, the sintering temperature is 1000℃, the heating rate is 15℃ / min, the holding time is 20h, and the cooling rate is 5℃ / min. The chip is then placed in a basket, and a conductive wire is installed at the upper end of the basket as an integrated cathode.

[0201] S3 Electrolysis of Thorium Oxide: Using a three-electrode system, the purified LiCl molten salt obtained in S1 is used as the reaction medium. The basketed thorium oxide powder obtained in S2 is used as the cathode, C is selected as the anode, and Ag / AgCl is used as the reference electrode. Then, a suitable voltage (-4V) is applied to the molten state for constant voltage electrolysis for 48 hours. The electrolytic reduction temperature is 600°C until the thorium oxide is completely converted to carbide.

[0202] S4 purifies the product: after the electrolysis is completed, the thorium carbide product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the thorium carbide product and the mixed molten salt, thereby obtaining pure thorium carbide for storage and standby use.

[0203] This embodiment also provides a carbonized thorium fuel, which is prepared by the above method.

[0204] The particle size of the carbonized thorium fuel prepared in this embodiment is 0.1-20 microns, and the purity is 98.4%.

[0205] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0206] Example 12

[0207] This embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking protactinium oxide as an example, the specific process flow for preparing protactinium carbide fuel is as follows, which differs from the method in Example 2 in that:

[0208] S1 Pretreatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (CsCl) into the electrolytic cell and heat it to a molten state. Insert an inert anode (W rod) and an active cathode (Ni foam) for pre-electrolysis at a voltage of 1.6V to purify the molten salt.

[0209] Preparation of S2 integrated cathode: Weigh 0.2g of protactinium oxide powder and directly place it in a stainless steel basket and compact it. Then, install a conductive wire on the top of the basket to serve as the integrated cathode. Weigh 1.0g of protactinium oxide powder and C powder (the mass ratio of the two is 0.1:5), mix them, and directly place them in a stainless steel basket and compact it. Then, install a conductive wire on the top of the basket to serve as the integrated cathode.

[0210] S3 Electrolysis of Protactinium Oxide: Using a three-electrode system, the purified LiCl molten salt obtained in S1 was used as the reaction medium. The basketed protactinium oxide-C powder obtained in S2 was used as the cathode, Pt was selected as the anode, and Ag / AgCl was used as the reference electrode. Then, a suitable voltage (-0.1V) was applied to the molten state for 48 hours of constant voltage electrolysis. The electrolytic reduction temperature was 600°C until the protactinium oxide was completely converted to carbide.

[0211] S4 purifies the product: after the electrolysis is completed, the protactinium carbide product obtained in S3 is taken out of the molten salt, and the surface of the protactinium carbide product and the mixed molten salt are removed by a solvent (ethanol) washing method to obtain pure protactinium carbide for storage and standby use.

[0212] This embodiment also provides a carbonized protactinium fuel, which is prepared by the above method.

[0213] The particle size of the protactinium carbide fuel prepared in this embodiment is 0.1-20 microns, and the purity is 98.8%.

[0214] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0215] Example 13

[0216] This embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking neptunium oxide as an example, the specific process flow for preparing neptunium carbide fuel is described below, which differs from the method in Example 2 in that:

[0217] S1 Pretreatment and purification of the molten salt medium: Weigh 50g of chloride molten salt (CaCl2) and add it to the electrolytic cell, then heat it to a molten state. Insert an inert anode (Mo rod) and an active cathode (Ni foam) for pre-electrolysis at a voltage of 3.9V to purify the molten salt.

[0218] Preparation of S2 integrated cathode: Weigh 5g of neptunium oxide powder, 5g of C powder and 0.1g of stearic acid, mix them and press them into chips in argon. The holding pressure of the tablet is 1Mpa, the holding time is 1min, the sintering temperature is 400℃, the heating rate is 10℃ / min, the holding time is 72h, and the cooling rate is 10℃ / min. Then put the chips into the basket.

[0219] A conductive wire is installed at the upper end of the basket as an integrated cathode;

[0220] S3 Electrolysis of NpO: Using a three-electrode system, the purified LiCl molten salt obtained in S1 was used as the reaction medium. The basketed NpO-C powder obtained in S2 was used as the cathode, Mo was selected as the anode, and Pt wire was used as the reference electrode. Then, a suitable current (0.1A) was applied to the molten state for 48 hours of constant current electrolysis. The electrolytic reduction temperature was 600°C until the NpO was completely converted to carbide.

[0221] S4 purifies the product: after the electrolysis is completed, the neptunium carbide product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the neptunium carbide product and the mixed molten salt, thereby obtaining pure neptunium carbide for storage and standby use.

[0222] This embodiment also provides a neptunium carbide fuel, which is prepared by the above method.

[0223] The particle size of the neptunium carbide fuel prepared in this embodiment is 0.1-20 microns, and the purity is 98.1%.

[0224] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0225] Example 14

[0226] This embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking plutonium oxide as an example, the specific process flow for preparing plutonium carbide fuel is described below, which differs from the method in Example 2 in the following ways:

[0227] S1 Pretreatment and purification of the molten salt medium: Weigh 50g of chloride molten salt (MgCl2) into the electrolytic cell and heat until molten. Insert an inert anode (C rod) and an active cathode (Ni foam) for pre-electrolysis at a current of 0.1A to purify the molten salt.

[0228] Preparation of S2 integrated cathode: Weigh 1.0 g of plutonium oxide powder and C powder (mass ratio of 5:10), mix them, and directly place them into a stainless steel basket for compaction. Then, install a conductive wire on the top of the basket to serve as the integrated cathode.

[0229] S3 Electrolysis of Plutonium Oxide: A three-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction medium. The basketed plutonium oxide-C powder obtained in S2 was used as the cathode, W was selected as the anode, and Mo wire was used as the reference electrode. A suitable current (5A) was applied to the molten state for 48 hours of constant current electrolysis at a temperature of 600°C until the plutonium oxide was completely converted to carbide.

[0230] S4 purifies the product: After the electrolysis is completed, the plutonium carbide product obtained in S3 is extracted from the molten salt and transferred to a vacuum distillation device for vacuum distillation to remove the surface of the plutonium carbide product and the mixed molten salt, thereby obtaining pure plutonium carbide for storage and standby use.

[0231] This embodiment also provides a carbonized plutonium fuel, which is prepared by the above method.

[0232] The carbonized plutonium fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.5%.

[0233] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0234] Example 15

[0235] This embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking americium oxide as an example, the specific process flow for preparing americium carbide fuel is described below, which differs from the method in Example 2 in that:

[0236] S1 Pretreatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (NaCl) into the electrolytic cell and heat until molten. Insert an inert anode (W rod) and an active cathode (Ni foam) for pre-electrolysis at a current of 5A to purify the molten salt.

[0237] Preparation of S2 integrated cathode: Weigh 0.1g of americium oxide powder, 10g of C powder and 0.5g of polyvinyl alcohol, mix them and press them into chips in argon. The holding pressure of the tablet is 10Mpa, the holding time is 30min, the sintering temperature is 900℃, the heating rate is 1℃ / min, the holding time is 36h, and the cooling rate is 20℃ / min. Then the chips are placed in a basket, and a conductive wire is installed at the upper end of the basket as an integrated cathode.

[0238] S3 Electrolysis of Americium Oxide: A three-electrode system was used, with the purified LiCl molten salt obtained in S1 as the reaction medium. The basketed americium oxide-C powder obtained in S2 was used as the cathode, ceramic was selected as the anode, and Ni wire was used as the reference electrode. A suitable current (10A) was applied to the molten state and constant current electrolysis was performed for 48 hours at a temperature of 600°C until the americium oxide was completely converted to carbide.

[0239] S4 purifies the product: after the electrolysis is completed, the americium carbide product obtained in S3 is extracted from the molten salt and then transferred to a vacuum distillation device for vacuum distillation to remove the surface of the americium carbide product and the mixed molten salt, thereby obtaining pure americium carbide for storage and standby use.

[0240] This embodiment also provides a carbonized americium fuel, which is prepared by the above method.

[0241] The carbonized americium fuel prepared in this embodiment has a particle size of 0.1-20 microns and a purity of 98.4%.

[0242] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0243] Example 16

[0244] This embodiment provides a process technology for electrolyzing actinide oxides for preparing carbide fuel. The key to this process is the pretreatment and purification of the molten salt medium, the preparation of an integrated cathode, the selection of appropriate electrodes and potentials, and the purification of the product. The main equipment used includes a primary sealed glove box, an electrolytic cell, an electrochemical workstation, a high-temperature furnace, and a DC power supply. Taking curium oxide as an example, the specific process flow for preparing curium carbide fuel is described below, which differs from the method in Example 2 in that:

[0245] S1 Pretreatment and purification of the molten salt medium: Weigh 50g of molten chloride salt (KCl) into the electrolytic cell and heat it to a molten state. Insert an inert anode (Mo rod) and an active cathode (Ni foam) for pre-electrolysis at a current of 10A to purify the molten salt.

[0246] Preparation of S2 integrated cathode: 10g of curium oxide powder, 0.1g of C powder and 0.1g of vinylidene fluoride were weighed and mixed, and then pressed and sintered into chips in argon. The holding pressure of the tablet was 20Mpa, the holding time was 15min, the sintering temperature was 1800℃, the heating rate was 20℃ / min, the holding time was 1h, and the cooling rate was 1℃ / min. The chips were then placed in a basket, and a conductive wire was installed at the upper end of the basket as an integrated cathode.

[0247] S3 electrolysis of curium oxide: Using a three-electrode system, the purified LiCl molten salt obtained in S1 was used as the reaction medium. The basketed curium oxide-C powder obtained in S2 was used as the cathode, C was selected as the anode, and LiPb was used as the reference electrode. Then, a suitable voltage (-2.1V) was applied in the molten state for constant voltage electrolysis for 48 hours. The electrolytic reduction temperature was 600°C until the curium oxide was completely converted to carbide.

[0248] S4 purifies the product: after the electrolysis is completed, the curium carbide product obtained in S3 is extracted from the molten salt and transferred to a vacuum distillation device for vacuum distillation to remove the surface of the curium carbide product and the mixed molten salt, so as to obtain pure curium carbide for storage and standby use.

[0249] This embodiment also provides a carbonized curium fuel, which is prepared by the above method.

[0250] The particle size of the carbonized curium fuel prepared in this embodiment is 0.1-20 microns, and the purity is 98.2%.

[0251] This embodiment adopts a new electrochemical method to prepare carbide fuel containing actinide nuclides. The key to the scheme of this embodiment is to select a suitable cathode, anode, reference electrode and voltage (current) for electrolysis. Compared with the traditional carbon thermal reduction preparation process, this process uses the principle of cathode molten salt electro-deoxidation to prepare carbide fuel. The oxygen of actinide oxide on the cathode is ionized, and the ionized oxygen moves to the anode through the molten salt, and is discharged and removed at the anode. This new method of generating carbide fuel on the cathode has the advantages of low reaction temperature, mild reaction conditions, low critical risk coefficient, simple operation steps, easy control of phase and reaction progress, and controllable product purity and particle size.

[0252] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing actinide carbide fuel, characterized in that: The following steps are involved: Actinide oxide, or a mixture of actinide oxide and carbon powder, is used as a cathode; When actinide oxide is used as cathode, a carbon anode is selected; or, when a mixture of actinide oxide and carbon powder is used as cathode, a corresponding anode is selected; Electrolytic reduction is carried out in the molten salt state to generate actinide carbides.

2. The method for preparing actinide carbide fuel according to claim 1, characterized in that: The following steps are also included: The molten salt is chloride molten salt. Before electrolytic reduction, the chloride molten salt is used as a medium. After being heated to a molten state, an inert anode and an active cathode are inserted for pre-electrolysis to purify the molten salt.

3. The method for preparing actinide carbide fuel according to claim 2, characterized in that: During pre-electrolysis, constant voltage electrolysis is adopted, 0V<electrolysis voltage<4V; Alternatively, constant current electrolysis is used, 0A<electrolysis current<10A.

4. The method for preparing actinide carbide fuel according to claim 2, characterized in that: The chloride molten salt is one or more of LiCl, NaCl, KCl, CsCl, CaCl2, and MgCl2; The inert anode is any one of C rod, Mo rod and W rod; The active cathode is Ni foam.

5. The method for preparing actinide carbide fuel according to claim 1, characterized in that: Actinide oxide is An x O y , 1≤x≤5, 1≤y≤10, where An is any one of Ac, Th, Pa, U, Np, Pu, Am, and Cm.

6. The method for preparing actinide carbide fuel according to claim 1, characterized in that: Using actinide oxide as cathode specifically includes the following steps: Putting actinide oxide powder into a basket or pressing and sintering actinide oxide powder into tablets and then putting the tablets into a basket as a cathode; The process of using a mixture of actinide oxide and carbon powder as a cathode specifically includes the following steps: Actinide oxide powder, C powder and a binder are mixed, pressed and sintered, and then placed in a basket, or a mixture of actinide oxide powder and C powder is placed in a basket as a cathode.

7. The method for preparing actinide carbide fuel according to claim 6, characterized in that: When the actinide oxide powder is pressed into a pellet and sintered and then packed into a basket as a cathode, the holding pressure of the pellet is 1-20 MPa, the holding time is 1-30 min, the sintering temperature is 400-1800°C, the heating rate is 1-20°C / min, the holding time is 1-72 h, and the cooling rate is 1-20°C / min; When actinide oxide powder, C powder and a binder are mixed, pressed and sintered, and then packed in a basket as a cathode, the holding pressure of the tablet is 1-20 MPa, the holding time is 1-30 min, the sintering temperature is 400-1800°C, the heating rate is 1-20°C / min, the holding time is 1-72h, and the cooling rate is 1-20°C / min.

8. The method for preparing actinide carbide fuel according to claim 6, characterized in that: The adhesive is any one or more of polyvinylidene fluoride, polyvinyl alcohol, acryl wax, stearic acid, zinc stearate, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, polyacrylonitrile and polyacrylate.

9. The method for preparing actinide carbide fuel according to claim 6, characterized in that: When the actinide oxide powder, C powder and binder are mixed, pressed, sintered and then packed into a basket, the mass ratio of the actinide oxide powder, C powder and binder is (0.1-10): (0.1-10): (0.1-1); Alternatively, when the actinide oxide powder and the C powder are put into a basket, the mass ratio of the actinide oxide powder to the C powder is (0.1-10):(0.1-10).

10. The method for preparing actinide carbide fuel according to claim 1, wherein: The corresponding anode is any one of Pt, Mo, W, ceramic, and carbon anode.

11. The method for preparing actinide carbide fuel according to claim 1, wherein: The system in which the electrolytic reduction process occurs is a three-electrode system, and a corresponding solid reference electrode is selected. The solid reference electrode is any one of Ag / AgCl, LiPb, Ni wire, Mo wire, and Pt wire.

12. The method for preparing actinide carbide fuel according to claim 1, wherein: During electrolytic reduction, constant voltage electrolysis is adopted, -4V≤electrolysis voltage<0V; Alternatively, constant current electrolysis is used, 0A<electrolysis current≤10A.

13. The method for preparing actinide carbide fuel according to claim 1, characterized in that: The electrolytic reduction also includes the following steps: Actinide carbides are generated at the cathode, the products are removed from the molten salt, and then transferred to a vacuum distillation apparatus for vacuum distillation to remove the adhering molten salt or the molten salt is removed by a solvent washing method.

14. The method for preparing actinide carbide fuel according to claim 1, wherein: The temperature of electrolytic reduction is 550-1000°C.

15. An actinide carbide fuel, characterized in that: It is prepared by the method according to any one of claims 1 to 14.

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