Separation method of aluminum alloy and application thereof

Abstract

The present application relates to the technical field of metal, and provide a kind of aluminium alloy separation method and its application, the aluminium alloy includes actinium aluminium alloy and / or lanthanum aluminium alloy;The separation method includes: aluminium alloy is mixed with molten state gallium chloride molten salt system to realize the separation of aluminium and remaining elements in the aluminium alloy;The gallium chloride molten salt system includes GaCl3-KCl molten salt, GaCl3-LiCl molten salt, GaCl3-NaCl molten salt or KGaCl4-LiGaCl4-NaGaCl4 molten salt;Aluminium in the aluminium alloy of the present application occurs displacement reaction with Ga (III) in gallium chloride molten salt system, generates liquid Ga metal and aluminium trichloride, and aluminium trichloride can be completely dissolved in molten salt, and remaining elements can be separated from molten salt in the form of precipitation.The method of the present application has the advantages of low experimental temperature, simple operation, low equipment requirement, low cost and the like.

Description

Technical Field

[0001] This invention relates to the field of metal technology, and in particular to a method for separating aluminum alloys and its application. Background Technology

[0002] In the nuclear field, aluminum is a component of fuels (UO2 / Al, U-Si / Al, U-Mo / Al and U-Al) and fuel cladding, and is also the most promising metal flux and electrode material for the pyrolytic separation of actinides in spent fuel reprocessing.

[0003] In the reprocessing of spent fuel, taking the recovery and purification of uranium from spent fuel as an example, the separation of uranium-aluminum alloys is necessary. Traditional methods for recovering U from U-Al alloys through chlorination volatilization are complex, using highly corrosive Cl2 or HCl at high temperatures, placing extremely stringent requirements on the corrosion resistance of the equipment. Furthermore, the formation of highly volatile, high-valence actinide chlorides cannot be avoided, resulting in low overall separation efficiency and limited feasibility for practical dry reprocessing of spent fuel. Other traditional electrochemical methods also pose significant challenges for the separation of uranium-aluminum alloys. Typically, uranium, which is more reactive than aluminum, preferentially dissolves at the anode to form uranium ions. Since the deposition potential difference between uranium and aluminum is small, uranium ions are reduced together with aluminum ions at the cathode to re-form Al alloys, making electrochemical separation of uranium-aluminum alloys difficult. Therefore, developing methods to effectively separate aluminum from aluminum alloys in the aforementioned fields is of great significance. Summary of the Invention

[0004] This invention provides a method for separating aluminum alloys and its application, which solves the problem of difficulty in separating aluminum elements in specific aluminum alloys in the prior art.

[0005] Specifically, the present invention provides a method for separating aluminum alloys, wherein the aluminum alloys include one or more combinations of actinium aluminum alloys, lanthanum aluminum alloys, and transition metal aluminum alloys; comprising:

[0006] The aluminum alloy is mixed with a molten gallium chloride salt system to achieve the separation of aluminum from other elements in the aluminum alloy;

[0007] The gallium chloride molten salt system includes GaCl3-KCl molten salt, GaCl3-LiCl molten salt, GaCl3-NaCl molten salt, or KGaCl4-LiGaCl4-NaGaCl4 molten salt.

[0008] According to the aluminum alloy separation method provided by the present invention, the molar ratio of GaCl3 to KCl in the GaCl3-KCl molten salt is 1:2 to 3:1;

[0009] The molar ratio of GaCl3 to LiCl in the GaCl3-LiCl molten salt is 1:2 to 3:1.

[0010] The molar ratio of GaCl3 to NaCl in the GaCl3-NaCl molten salt is 1:2 to 3:1.

[0011] The KGaCl4-LiGaCl4-NaGaCl4 molten salt composition has any molar ratio.

[0012] According to the aluminum alloy separation method provided by the present invention, the molar ratio of GaCl3 to KCl in the GaCl3-KCl molten salt is 1:1;

[0013] The molar ratio of GaCl3 to LiCl in the GaCl3-LiCl molten salt is 1:1;

[0014] The molar ratio of GaCl3 to NaCl in the GaCl3-NaCl molten salt is 1:1.

[0015] The KGaCl4-LiGaCl4-NaGaCl4 molten salt contains KGaCl4, LiGaCl4, and NaGaCl4 in any molar ratio.

[0016] According to the aluminum alloy separation method provided by the present invention, the system temperature during mixing is 100-210°C.

[0017] According to the aluminum alloy separation method provided by the present invention, when the gallium chloride molten salt system is GaCl3-KCl molten salt, the system temperature is 190-210°C, preferably 200°C;

[0018] When the gallium chloride molten salt system is GaCl3-LiCl molten salt, the system temperature is 170-200℃, preferably 180℃;

[0019] When the gallium chloride molten salt system is GaCl3-NaCl molten salt, the system temperature is 170-200℃, preferably 180℃;

[0020] When the gallium chloride molten salt system is KGaCl4-LiGaCl4-NaGaCl4 molten salt, the system temperature is 150-200℃, preferably 180℃.

[0021] According to the aluminum alloy separation method provided by the present invention, the mixing is carried out under anhydrous and oxygen-free conditions;

[0022] Preferably, the mixing is carried out under a protective gas; more preferably, the protective gas includes argon.

[0023] The method for separating the aluminum alloy according to the present invention includes:

[0024] The gallium chloride molten salt system is heated and melted to obtain a molten gallium chloride molten salt system;

[0025] An aluminum alloy is added to the molten gallium chloride salt system, and the system temperature is maintained at 100-210°C to obtain Ga metal and a metal chloride separated from the aluminum alloy. The metal chloride does not contain aluminum.

[0026] Separate the Ga metal;

[0027] The metal chloride was separated and purified.

[0028] According to the aluminum alloy separation method provided by the present invention, the separation of the metal chloride includes: obtaining the metal chloride by filtering with a metal mesh or by discharging from the bottom of the system; preferably, the mesh size of the metal mesh is 200 to 2000 mesh;

[0029] And / or, purifying the metal chloride includes: vacuum distillation at 400–500°C.

[0030] According to the aluminum alloy separation method provided by the present invention, the aluminum element in the reaction system is controlled to be in excess so that the Ga element in the gallium chloride molten salt system reacts completely.

[0031] The present invention also provides the application of the aluminum alloy separation method described above in spent fuel reprocessing.

[0032] This invention provides a method for separating aluminum alloys and its application. By directly carrying out a chemical reaction in a gallium chloride molten salt system, the target element in the aluminum alloy is recovered through chemical precipitation. The precipitated component is small and easily purified. No other impurities are introduced. The entire process is simple to operate, requires low experimental temperature, has low equipment requirements, is highly practical, and economical. This provides a new approach for the efficient separation of actinium-aluminum alloys and has significant implications for the nuclear industry. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the uranium-aluminum alloy separation process provided in Example 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of Ga metal and uranium trichloride precipitate, the products of uranium-aluminum alloy separation provided in Example 1 of this invention;

[0036] Figure 3 This is a schematic diagram of the vacuum distillation apparatus provided in Embodiment 1 of the present invention;

[0037] Figure 4 This is a schematic diagram of the uranium trichloride product obtained by vacuum distillation in Example 1 of the present invention;

[0038] Figure 5 This is the XRD characterization diagram of Ga metal and uranium trichloride obtained in Example 1 of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0040] The following is combined with Figures 1-5 The present invention describes a method for separating aluminum alloys and its applications.

[0041] In an embodiment of the present invention, a method for separating aluminum alloys is provided, wherein the aluminum alloys include one or more combinations of actinium aluminum alloys, lanthanum aluminum alloys, and transition metal aluminum alloys; comprising:

[0042] The aluminum alloy is mixed with a molten gallium chloride salt system to achieve the separation of aluminum from other elements in the aluminum alloy;

[0043] The gallium chloride molten salt system includes GaCl3-KCl molten salt, GaCl3-LiCl molten salt, GaCl3-NaCl molten salt, or KGaCl4-LiGaCl4-NaGaCl4 molten salt.

[0044] The actinium-aluminum alloys in this invention include uranium-aluminum alloys, UO2 / Al, U-Si / Al, U-Mo / Al, etc.

[0045] The lanthanum-aluminum alloys in this invention include La-Al, Ce-Al, Sm-Al alloys, etc.

[0046] The transition metal aluminum alloys in this invention include Fe-Al, Si-Al, Mg-Al alloys, etc.

[0047] Using the method of this invention, aluminum in the aluminum alloy undergoes a displacement reaction with Ga(III) in the gallium chloride molten salt system to generate liquid Ga metal and aluminum trichloride, which is completely soluble in the molten salt. The target metal in the aluminum alloy undergoes an oxidation reaction with Ga(III) in the gallium chloride molten salt system to generate liquid Ga metal and the target metal chloride. Since the target metal chloride is insoluble in the gallium chloride molten salt system, it can be separated from the molten salt by precipitation. This invention achieves highly selective recovery of the target element from aluminum alloys and has advantages such as low experimental temperature, simple operation, low equipment requirements, and low cost. Therefore, it is possible to more simply, environmentally friendly, and economically achieve highly selective recovery of the target metal element from aluminum alloys in a gallium chloride molten salt system.

[0048] In some embodiments of the present invention, the molar ratio of GaCl3 to KCl in the GaCl3-KCl molten salt is 1:2 to 3:1;

[0049] The molar ratio of GaCl3 to LiCl in the GaCl3-LiCl molten salt is 1:2 to 3:1.

[0050] The molar ratio of GaCl3 to NaCl in the GaCl3-NaCl molten salt is 1:2 to 3:1.

[0051] The KGaCl4-LiGaCl4-NaGaCl4 molten salt composition has any molar ratio.

[0052] In some embodiments of the present invention, the molar ratio of GaCl3 to KCl in the GaCl3-KCl molten salt is 1:1;

[0053] The molar ratio of GaCl3 to LiCl in the GaCl3-LiCl molten salt is 1:1;

[0054] The molar ratio of GaCl3 to NaCl in the GaCl3-NaCl molten salt is 1:1.

[0055] The KGaCl4-LiGaCl4-NaGaCl4 molten salt contains KGaCl4, LiGaCl4, and NaGaCl4 in any molar ratio.

[0056] In some embodiments of the present invention, the system temperature is 100–210°C during the mixing process.

[0057] In some embodiments of the present invention, when the gallium chloride molten salt system is GaCl3-KCl molten salt, the system temperature is 190-210°C, preferably 200°C;

[0058] When the gallium chloride molten salt system is GaCl3-LiCl molten salt, the system temperature is 170-200℃, preferably 180℃;

[0059] When the gallium chloride molten salt system is GaCl3-NaCl molten salt, the system temperature is 170-200℃, preferably 180℃;

[0060] When the gallium chloride molten salt system is KGaCl4-LiGaCl4-NaGaCl4 molten salt, the system temperature is 150-200℃, preferably 180℃.

[0061] In some embodiments of the present invention, the mixing is carried out under anhydrous and oxygen-free conditions;

[0062] Preferably, the mixing is carried out under a protective gas; more preferably, the protective gas includes argon.

[0063] In some embodiments of the present invention, the following are included:

[0064] The gallium chloride molten salt system is heated and melted to obtain a molten gallium chloride molten salt system;

[0065] An aluminum alloy is added to the molten gallium chloride salt system, and the system temperature is maintained at 100-210°C to obtain Ga metal and a metal chloride separated from the aluminum alloy. The metal chloride does not contain aluminum.

[0066] Separate the Ga metal;

[0067] The metal chloride was separated and purified.

[0068] In some embodiments of the present invention, separating the metal chloride includes: obtaining the metal chloride by filtering with a metal mesh or by discharging from the bottom of the system; preferably, the mesh size of the metal mesh is 200 to 2000 mesh;

[0069] And / or, purifying the metal chloride includes: vacuum distillation at 400–500°C.

[0070] In some embodiments of the present invention, an excess of aluminum is controlled in the reaction system to completely precipitate the Ga element in the gallium chloride molten salt system.

[0071] The reaction system of the present invention can be recycled. For example, if the Ga element in the molten salt system is not completely reacted, aluminum alloy can be added for separation until the Ga element is completely replaced to obtain a molten salt containing aluminum chloride. Furthermore, the molten salt containing aluminum chloride can be applied in other fields using conventional methods in the art.

[0072] In some embodiments of the present invention, the application of the aluminum alloy separation method described above in spent fuel reprocessing is also provided.

[0073] Unless otherwise specified, the techniques used in the embodiments are conventional methods well known to those skilled in the art, and the electrolysis products were characterized using X-ray diffraction (Bruker, D8 Advance). In the embodiments, all reagents were commercially available conventional raw materials purchased from Innovent and Energie.

[0074] In the preparation of the molten salt system in this invention, the reagents are first stored in a glove box (water and oxygen content are both less than 1 ppm). They are then prepared at a molar ratio of 1:1. High-purity anhydrous LiCl and GaCl3 (both with a purity greater than 99.9%) are mixed thoroughly and placed in a corundum crucible, then heated to 200°C to obtain the GaCl3-LiCl molten salt.

[0075] The preparation methods for GaCl3-KCl molten salt, GaCl3-NaCl molten salt, and KGaCl4-LiGaCl4-NaGaCl4 molten salt are basically the same as those for GaCl3-LiCl molten salt, except that the raw materials and their molar ratios are determined according to the requirements of the corresponding molten salt.

[0076] The uranium-aluminum alloy in this invention is a mixture of UAl3 and UAl2.

[0077] Example 1

[0078] A method for separating uranium-aluminum alloys, the process flow diagram of which is shown below. Figure 1 As shown, the specific steps are as follows:

[0079] (1) Place 100g of GaCl3-LiCl molten salt with a molar ratio of 1:1 into an alumina crucible and control the temperature at 180℃.

[0080] (2) The uranium-aluminum alloy was placed in the above-mentioned molten GaCl3-LiCl molten salt and reacted. The reaction was carried out under argon protective gas and was completed within 2 hours. The reaction products are as follows. Figure 2 As shown, it includes Ga metal and uranium trichloride precipitate.

[0081] (3) Ga metal was obtained by discharging the material at the bottom of the reaction system. The XRD characterization results of the Ga metal are as follows: Figure 5 As shown.

[0082] (4) A yellow-green precipitate was obtained by filtering with a 1000-mesh molybdenum mesh; the yellow-green precipitate was then vacuum distilled at 500℃ for 6 hours (vacuum apparatus such as...). Figure 3 The product is obtained as shown. Figure 4 As shown, the XRD characterization results are as follows: Figure 5 As shown, it is uranium trichloride.

[0083] This demonstrates that the method of the present invention can achieve efficient separation of uranium-aluminum alloys, with a gallium recovery rate of over 99% and a uranium recovery rate of over 98%.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for separating an aluminum alloy, wherein the aluminum alloy comprises one or more combinations of actinium aluminum alloy, lanthanum aluminum alloy, and transition metal aluminum alloy; characterized in that, include: The aluminum alloy is mixed with a molten gallium chloride salt system to achieve the separation of aluminum from other elements in the aluminum alloy; The gallium chloride molten salt system includes GaCl3-KCl molten salt, GaCl3-LiCl molten salt, GaCl3-NaCl molten salt, or KGaCl4-LiGaCl4-NaGaCl4 molten salt.

2. The method for separating aluminum alloys according to claim 1, characterized in that, The molar ratio of GaCl3 to KCl in the GaCl3-KCl molten salt is 1:2 to 3:

1. The molar ratio of GaCl3 to LiCl in the GaCl3-LiCl molten salt is 1:2 to 3:

1. The molar ratio of GaCl3 to NaCl in the GaCl3-NaCl molten salt is 1:2 to 3:

1.

3. The method for separating aluminum alloys according to claim 2, characterized in that, The molar ratio of GaCl3 to KCl in the GaCl3-KCl molten salt is 1:1; The molar ratio of GaCl3 to LiCl in the GaCl3-LiCl molten salt is 1:1; The molar ratio of GaCl3 to NaCl in the GaCl3-NaCl molten salt is 1:

1.

4. The method for separating aluminum alloys according to any one of claims 1 to 3, characterized in that, During the mixing process, the system temperature is 100~210℃.

5. The method for separating aluminum alloys according to claim 4, characterized in that, When the gallium chloride molten salt system is GaCl3-KCl molten salt, the system temperature is 190~210℃; When the gallium chloride molten salt system is GaCl3-LiCl molten salt, the system temperature is 170~200℃; When the gallium chloride molten salt system is GaCl3-NaCl molten salt, the system temperature is 170~200℃; When the gallium chloride molten salt system is KGaCl4-LiGaCl4-NaGaCl4 molten salt, the system temperature is 150~200℃.

6. The method for separating aluminum alloys according to claim 5, characterized in that, When the gallium chloride molten salt system is GaCl3-KCl molten salt, the system temperature is 200℃; When the gallium chloride molten salt system is GaCl3-LiCl molten salt, the system temperature is 180℃; When the gallium chloride molten salt system is GaCl3-NaCl molten salt, the system temperature is 180℃; When the gallium chloride molten salt system is KGaCl4-LiGaCl4-NaGaCl4 molten salt, the system temperature is 180℃.

7. The method for separating aluminum alloys according to any one of claims 1 to 3, characterized in that, The mixing is carried out under anhydrous and oxygen-free conditions.

8. The method for separating aluminum alloys according to claim 7, characterized in that, The mixing is carried out under a protective gas atmosphere.

9. The method for separating aluminum alloys according to claim 8, characterized in that, The protective gas includes argon.

10. The method for separating aluminum alloys according to any one of claims 1 to 3, characterized in that, include: The gallium chloride molten salt system is heated and melted to obtain a molten gallium chloride molten salt system; An aluminum alloy is added to the molten gallium chloride salt system, and the system temperature is maintained at 100~210℃ to obtain Ga metal and metal chloride separated from the aluminum alloy. The metal chloride does not contain aluminum. Separate the Ga metal; The metal chloride was separated and purified.

11. The method for separating aluminum alloys according to claim 10, characterized in that, Separating the metal chloride includes: obtaining the metal chloride by filtering with a metal mesh or by discharging from the bottom of the system; And / or, purifying the metal chloride includes: vacuum distillation at 400-500°C.

12. The method for separating aluminum alloys according to claim 11, characterized in that, The mesh size of the metal mesh is 200-2000 mesh.

13. The method for separating aluminum alloys according to any one of claims 1 to 3, characterized in that, An excess of aluminum is controlled in the reaction system to ensure that the Ga element in the gallium chloride molten salt system reacts completely.

14. The application of the aluminum alloy separation method according to any one of claims 1 to 13 in spent fuel reprocessing.

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