A method for producing a granite-based high-level waste form using a laser

Abstract

This application discloses a method for preparing granite-based high-level radioactive waste solids using laser technology, comprising the following steps: S1, grinding and mixing high-level radioactive waste powder and granite powder uniformly to obtain a dry and uniform mixed powder; S2, placing the mixed powder into a crucible mold, and then performing laser sintering on the mixed powder in the crucible mold using a laser device to obtain a high-level radioactive waste solid; S3, cooling the high-level radioactive waste solid and then separating the high-level radioactive waste solid from the crucible mold. This application utilizes laser technology to prepare granite-based high-level radioactive waste solids, which is highly efficient and convenient. The laser device enables rapid heating, allowing for the effective solidification of complex high-level radioactive waste. It effectively increases the solid content of complex waste, reduces the volatilization of low-melting-point volatile substances in complex waste, and the resulting high-level radioactive waste solid has advantages such as large inclusion capacity and good chemical stability, effectively suppressing high-level radioactive waste pollution of the ecological environment.

Description

Technical Field

[0001] This invention relates to the field of high-level radioactive waste treatment, and specifically to a method for preparing granite-based high-level radioactive waste solids using laser technology. Background Technology

[0002] The widespread use of nuclear energy and the rapid development of nuclear technology inevitably generate a large amount of radioactive waste. Among them, high-level radioactive waste (HLW) poses a potential threat to human health and the living environment due to its strong radioactivity, high toxicity, long half-life, and high heat release rate. It has become one of the most difficult radioactive wastes to handle and has to some extent restricted the development of the nuclear industry.

[0003] Granite is a deep-seated acidic igneous rock formed by the cooling and solidification of magma deep underground, or a gneiss-like or migmatitic rock formed by the metamorphism of magma and sedimentary rocks. Its main components are SiO2 and Al2O3, and it is characterized by low permeability, good thermal stability, strong corrosion resistance, and hardness. In addition, some nuclides (such as...) have been found... 227 Ac、 232 Th、 235,238 U and other minerals (such as sphene, monazite, zircon, etc.) can be stably stored in minerals for a long time. Therefore, using granite as a curing substrate may combine the advantages of both glass and ceramic curing.

[0004] During the solidification process, various substances react and transfer with each other, resulting in solidified bodies with excellent physicochemical properties. Currently, obtaining solidified bodies with superior physicochemical properties using traditional high-temperature sintering (muffle furnace) requires high sintering temperatures and long sintering times. However, due to the complex composition of high-level radioactive waste and the significant differences in the physicochemical properties of its components, traditional sintering is insufficient to meet the requirements for solidifying all components of complex high-level radioactive waste. While microwave sintering can reduce energy consumption to some extent, the varying microwave absorption capabilities and coupling properties of different media can easily lead to hot spots. Therefore, a method is needed to reduce sintering temperature, shorten sintering time, and effectively solidify high-level radioactive waste. Summary of the Invention

[0005] To address the above-mentioned problems and overcome at least one deficiency, this invention proposes a method for preparing granite-based high-level radioactive waste solidification using laser technology.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for preparing granite-based high-level radioactive waste solidification using laser technology includes the following steps:

[0008] S1. Grind and mix the high-level radioactive waste powder and granite powder evenly to obtain a dry and uniform mixed powder;

[0009] S2. Place the mixed powder into a crucible mold, and then use a laser device to perform laser sintering on the mixed powder in the crucible mold to obtain a solidified high-level radioactive waste.

[0010] S3. Cool the high-level radioactive waste solidified body, and then separate the high-level radioactive waste solidified body from the crucible mold.

[0011] This application utilizes laser technology to prepare granite-based high-level radioactive waste solidification, which is highly efficient and convenient. The laser device enables rapid heating, allowing for the effective solidification of complex high-level radioactive waste. It effectively increases the solid content of complex waste, reduces the volatilization of low-melting-point volatile substances, and the resulting high-level radioactive waste solidification exhibits advantages such as large inclusion capacity and good chemical stability, effectively suppressing high-level radioactive waste pollution of the ecological environment. This application has high practical value and development potential.

[0012] In practical applications, the granite powder can be sourced from various natural rocks across the country, including igneous and metamorphic rocks.

[0013] In one embodiment of the present invention, the high-level radioactive waste powder accounts for 5% to 50% of the weight percentage of the mixed powder.

[0014] In one embodiment of the present invention, the granite powder is obtained by mechanically crushing natural rock, igneous rock or metamorphic rock. The mechanical crushing method is: crushing with a high-speed pulverizer for 1 min-3 min, crushing 1-5 times, to obtain granite powder with a particle size of 1 μm-100 μm.

[0015] More specifically, the process involves pulverizing for 1-2 minutes to obtain granite powder with a particle size of 1μm-75μm.

[0016] In one embodiment of the present invention, before the granite powder is mixed with the high-level radioactive waste powder, a drying step is further included: evaporating by ventilation at a temperature between room temperature and 200°C for 1 to 24 hours.

[0017] More specifically, it involves ventilating and drying at 70℃~100℃ for 3h~12h.

[0018] In one embodiment of the present invention, the natural granite powder and the high-level radioactive waste powder are mixed by wet grinding.

[0019] In one embodiment of the present invention, the wet grinding and mixing specifically involves grinding twice under anhydrous ethanol until the anhydrous ethanol is completely evaporated, resulting in a dry and uniformly mixed powder.

[0020] In one embodiment of the present invention, the output power of the laser device is 10KW to 100KW, which can be adjusted from 10% to 100%, and the scanning rate is 20 to 150mm / s.

[0021] In one embodiment of the present invention, the laser sintering temperature is 800℃~1600℃.

[0022] More specifically, 1000–1500℃.

[0023] In one embodiment of the present invention, step S3 is implemented by a cooling demolding mechanism, the cooling demolding mechanism comprising:

[0024] A conveying assembly having a conveyor belt, the surface of which has a first connecting structure, the conveyor belt including an upper conveying section located at the top and a lower conveying section located at the bottom;

[0025] The crucible mold has a second connecting structure at the bottom, which is detachably connected to the first connecting structure.

[0026] The first air blowing nozzle is located above the upper conveying section and is used to blow air onto the crucible mold on the upper conveying section.

[0027] A spray head, located below the lower conveyor section, is used to spray water onto the crucible mold on the lower conveyor section.

[0028] The second air nozzle is located below the lower conveying section and is used to blow air onto the crucible mold after it has been sprayed with water by the spray nozzle.

[0029] A vacuum suction cup is movably located below the lower conveying section and is used to extend into the crucible mold after being blown by the second blower nozzle, and to vacuum-adhere to the high-level radioactive waste solidified body.

[0030] A telescopic element is located below the lower conveying section. The movable rod of the telescopic element is fixed to the vacuum suction cup. The telescopic element is used to drive the vacuum suction cup to move up and down.

[0031] After sintering, the high-level radioactive waste solidified body needs to be separated from the crucible mold. Current separation methods are inconvenient and even render the crucible mold disposable. The principle of the cooling and demolding mechanism in this application is as follows: The crucible mold is mounted on a conveyor belt via a second connecting structure that engages with the first connecting structure. The conveyor belt moves the crucible mold. Initially, the crucible mold is located in the upper conveying section and undergoes preliminary cooling via a first air nozzle. When the crucible mold is conveyed to the lower conveying section (at this time, the crucible mold opening faces downwards), a spray nozzle sprays water onto the crucible mold. The water quickly cools the crucible mold, and due to gravity, the heated water quickly flows down from the crucible mold. The crucible mold continues to be conveyed, and a second air nozzle blows air to cool and dry the crucible mold after the water spray. Finally, a telescopic element drives a vacuum suction cup to extend into the crucible mold after the second air nozzle has blown air, where it vacuum-adheres the high-level radioactive waste solidified body. Then, the telescopic element moves the vacuum suction cup downwards, simultaneously moving the high-level radioactive waste solidified body downwards and detaching it from the crucible mold.

[0032] In practical applications, there are various ways to fix the crucible mold on the conveyor belt. In one embodiment of the present invention, in order to facilitate disassembly and assembly, the second connecting structure is rotated and snapped into the first connecting structure.

[0033] The beneficial effects of this invention are as follows: This application utilizes laser technology to prepare granite-based high-level radioactive waste solidification, which is highly efficient and convenient. Rapid heating can be achieved through the laser device, enabling effective solidification of complex high-level radioactive waste. This significantly increases the solid content of complex waste, reduces the volatilization of low-melting-point volatile substances, and the resulting high-level radioactive waste solidification exhibits advantages such as large inclusion capacity and good chemical stability, effectively suppressing high-level radioactive waste pollution of the ecological environment. This application has high practical value and development potential. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the cooling and demolding mechanism.

[0035] The labels for the attached figures are as follows:

[0036] 1. Conveying assembly; 11. Conveyor belt; 111. Upper conveying section; 112. Lower conveying section; 2. Crucible mold; 3. First air blowing nozzle; 4. Spray head; 5. Second air blowing nozzle; 6. Vacuum suction cup; 7. Telescopic element. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] The present invention will now be described in detail with reference to the accompanying drawings.

[0041] Example 1

[0042] A method for preparing granite-based high-level radioactive waste solidification using laser technology includes the following steps:

[0043] S1. The amphibole granulite (mined from Xiaolaihe mining area in Qingyuan, Liaoning) was crushed to 100-200 mesh to prepare granite powder, and then dried at 90℃ for 12 hours.

[0044] The same molar amounts of BaO, CdO, Cr2O3, CsNO3, Fe2O3, La2O3, MoO3, Na2CO3, Ni2O3, PdO, Rb2CO3, Rh2O3, RuO2, Sm2O3, SrSO4, and ZrO2 were mixed evenly to prepare simulated high-level radioactive waste powder, which was then dried and pretreated at 90℃ for 12 h.

[0045] The simulated high-level radioactive waste powder and granite powder are ground and mixed evenly to obtain a dry and uniform mixed powder, wherein the simulated high-level radioactive waste powder accounts for 5% to 50% of the mass of the mixed powder.

[0046] S2. Place the mixed powder into a crucible mold, and then use a laser device to perform laser sintering on the mixed powder in the crucible mold to obtain a solidified high-level radioactive waste.

[0047] S3. Cool the solidified high-level radioactive waste.

[0048] This application utilizes laser technology to prepare granite-based high-level radioactive waste solidification, which is highly efficient and convenient. The laser device enables rapid heating, allowing for the effective solidification of complex high-level radioactive waste. It effectively increases the solid content of complex waste, reduces the volatilization of low-melting-point volatile substances, and the resulting high-level radioactive waste solidification exhibits advantages such as large inclusion capacity and good chemical stability, effectively suppressing high-level radioactive waste pollution of the ecological environment. This application has high practical value and development potential.

[0049] In practical applications, granite powder can be sourced from various natural rocks across the country, including igneous and metamorphic rocks.

[0050] In this embodiment, the natural granite powder and the simulated high-level radioactive waste powder were mixed using a wet grinding process. Specifically, the wet grinding process involved grinding twice with anhydrous ethanol, allowing the anhydrous ethanol to completely evaporate, resulting in a dry, uniformly mixed powder.

[0051] In this embodiment, the laser sintering temperature is 1300℃, the laser device output power is 10KW, and the scanning rate is 100mm / s.

[0052] In this embodiment, step S3 further includes the step of separating the high-level radioactive waste solidified body from the crucible mold.

[0053] Tests have shown that the high-level radioactive waste solidified body prepared by laser has a large capacity for containing high-level radioactive waste, contains a wide variety of radionuclides, and has excellent mechanical properties.

[0054] Example 2

[0055] A method for preparing granite-based high-level radioactive waste solidification using laser technology includes the following steps:

[0056] S1. The amphibole granulite (mined from Xiaolaihe mining area in Qingyuan, Liaoning) was crushed to 100-200 mesh to prepare granite powder, and then dried at 90℃ for 12 hours.

[0057] BaO, CsNO3, Fe2O3, MoO3, Na2CO3, PdO, Rb2CO3, SrSO4, and ZrO2 were mixed evenly in equal molar amounts to prepare simulated high-level radioactive waste powder, which was then dried and pretreated at 90℃ for 12h.

[0058] The simulated high-level radioactive waste powder and granite powder are ground and mixed evenly to obtain a dry and uniform mixed powder, wherein the simulated high-level radioactive waste powder accounts for 5% to 50% of the mass of the mixed powder.

[0059] S2. Place the mixed powder into a crucible mold, and then use a laser device to perform laser sintering on the mixed powder in the crucible mold to obtain a solidified high-level radioactive waste.

[0060] S3. Cool the solidified high-level radioactive waste.

[0061] This application utilizes laser technology to prepare granite-based high-level radioactive waste solidification, which is highly efficient and convenient. The laser device enables rapid heating, allowing for the effective solidification of complex high-level radioactive waste. It effectively increases the solid content of complex waste, reduces the volatilization of low-melting-point volatile substances, and the resulting high-level radioactive waste solidification exhibits advantages such as large inclusion capacity and good chemical stability, effectively suppressing high-level radioactive waste pollution of the ecological environment. This application has high practical value and development potential.

[0062] In practical applications, granite powder can be sourced from various natural rocks across the country, including igneous and metamorphic rocks.

[0063] In this embodiment, the natural granite powder and the simulated high-level radioactive waste powder were mixed using a wet grinding process. Specifically, the wet grinding process involved grinding twice with anhydrous ethanol, allowing the anhydrous ethanol to completely evaporate, resulting in a dry, uniformly mixed powder.

[0064] In this embodiment, the laser sintering temperature is 1300℃, the laser device output power is 10KW, and the scanning rate is 100mm / s.

[0065] In this embodiment, step S3 further includes the step of separating the high-level radioactive waste solidified body from the crucible mold.

[0066] Tests have shown that the high-level radioactive waste solidified body prepared by laser has a large capacity for containing high-level radioactive waste, contains a wide variety of radionuclides, and has excellent mechanical properties.

[0067] Example 3

[0068] like Figure 1 As shown, this embodiment discloses a cooling demolding mechanism that can be used in step S3 of Embodiments 1 and 2. The cooling demolding mechanism of this embodiment includes:

[0069] The conveying assembly 1 has a conveyor belt 11, the surface of which has a first connection structure. The conveyor belt 11 includes an upper conveying section 111 located at the top and a lower conveying section 112 located at the bottom.

[0070] The crucible mold 2 has a second connecting structure at the bottom, and the second connecting structure is detachably connected to the first connecting structure.

[0071] The first air blowing nozzle 3 is located above the upper conveying section 111 and is used to blow air onto the crucible mold 2 on the upper conveying section 111.

[0072] Spray head 4, located below the lower conveying section 112, is used to spray water onto the crucible mold 2 on the lower conveying section 112;

[0073] The second air nozzle 5 is located below the lower conveying section 112 and is used to blow air onto the crucible mold 2 after it has been sprayed with water by the spray nozzle 4.

[0074] Vacuum suction cup 6 is movably located below the lower conveying section 112 and is used to extend into the crucible mold 2 after being blown by the second blow nozzle 5, and to vacuum adsorb the high-level radioactive waste solidified body.

[0075] The telescopic element 7 is located below the lower conveying section 112. The movable rod of the telescopic element 7 is fixed to the vacuum suction cup 6. The telescopic element 7 is used to drive the vacuum suction cup 6 to move up and down.

[0076] After sintering, the high-level radioactive waste solidified body needs to be separated from the crucible mold 2. The current separation method is inconvenient and even makes the crucible mold 2 a disposable item. The principle of the cooling and demolding mechanism of this application is as follows: The crucible mold 2 is installed on the conveyor belt 11 through the cooperation of the second connecting structure and the first connecting structure. The conveyor belt 11 drives the crucible mold 2 to move. The crucible mold 2 is first located in the upper conveying part 111 and is initially cooled by the first blowing nozzle 3. When the crucible mold 2 is conveyed to the lower conveying part 112 (at this time, the opening of the crucible mold 2 is facing downward), the spray nozzle 4 sprays water onto the crucible mold 2. The water can quickly cool the crucible mold 2, and due to the effect of gravity, the water that has absorbed heat can quickly flow down from the crucible mold 2. Then the crucible mold 2 continues to be conveyed, and the second blowing nozzle 5 blows air to cool and dry the crucible mold 2 after it has been sprayed with water by the spray nozzle 4. Finally, the telescopic element 7 drives the vacuum suction cup 6 to extend into the crucible mold 2 after it has been blown by the second blowing nozzle 5, and vacuum adsorbs it with the high-level radioactive waste solidified body. Then the telescopic element 7 drives the vacuum suction cup 6 to move downward. When moving downward, the vacuum suction cup 6 drives the high-level radioactive waste solidified body to move downward synchronously and detach from the crucible mold 2.

[0077] In practical applications, there are various ways to fix the crucible mold 2 on the conveyor belt 11. In this embodiment, in order to facilitate disassembly and assembly, the second connecting structure and the first connecting structure are rotated and snapped together.

[0078] The above description is merely a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, whether directly or indirectly applied to other related technical fields, are similarly included within the scope of protection of the present invention.

Claims

1. A method for producing a granitic base high-level waste form using a laser, characterized by, Includes the following steps: S1. Grind and mix the high-level radioactive waste powder and granite powder evenly to obtain a dry and uniform mixed powder; S2. Place the mixed powder into a crucible mold, and then use a laser device to perform laser sintering on the mixed powder in the crucible mold to obtain a solidified high-level radioactive waste. S3. Cool the high-level radioactive waste solidified body, and then separate the high-level radioactive waste solidified body from the crucible mold; Step S3 is implemented by a cooling demolding mechanism, which includes: A conveying assembly having a conveyor belt, the surface of which has a first connecting structure, the conveyor belt including an upper conveying section located at the top and a lower conveying section located at the bottom; The crucible mold has a second connecting structure at the bottom, which is detachably connected to the first connecting structure. The first air blowing nozzle is located above the upper conveying section and is used to blow air onto the crucible mold on the upper conveying section. A spray head, located below the lower conveyor section, is used to spray water onto the crucible mold on the lower conveyor section. The second air nozzle is located below the lower conveying section and is used to blow air onto the crucible mold after it has been sprayed with water by the spray nozzle. A vacuum suction cup is movably located below the lower conveying section and is used to extend into the crucible mold after being blown by the second blower nozzle, and to vacuum-adhere to the high-level radioactive waste solidified body. A telescopic element is located below the lower conveying section. The movable rod of the telescopic element is fixed to the vacuum suction cup. The telescopic element is used to drive the vacuum suction cup to move up and down.

2. The method of claim 1, wherein the method is characterized by, The high-level radioactive waste powder accounts for 5% to 50% of the weight of the mixed powder.

3. The method for preparing granite-based high-level radioactive waste solidification using laser as described in claim 1, characterized in that, The granite powder is obtained by mechanically crushing natural rocks, igneous rocks, or metamorphic rocks. The mechanical crushing method is as follows: crushing with a high-speed pulverizer for 1-3 minutes, 1-5 times, to obtain granite powder with a particle size of 1μm-100μm.

4. The method of claim 1, wherein the method is characterized by, Before the granite powder is mixed with the high-level radioactive waste powder, a drying step is also included: evaporating the powder under ventilation at a temperature between room temperature and 200°C for 1 to 24 hours.

5. The method of claim 1, wherein the method is characterized by, The granite powder and the high-level radioactive waste powder are mixed by wet grinding.

6. The method of claim 5, wherein the laser is a YAG laser. The wet grinding and mixing process specifically involves grinding twice under anhydrous ethanol until the anhydrous ethanol has completely evaporated, resulting in a dry and uniformly mixed powder.

7. The method of claim 1, wherein the method is characterized by, The output power of the laser device is 10KW to 100KW, which can be adjusted from 10% to 100%, and the scanning rate is 20 to 150mm / s.

8. The method for preparing granite-based high-level radioactive waste solidification using laser as described in claim 1, characterized in that, The laser sintering temperature is 800℃~1600℃.

9. The method of claim 1, wherein the method is characterized by, The second connecting structure is rotated and snapped into place with the first connecting structure.

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