A method for preparing silver-loaded stainless steel filter media for polonium capture

Abstract

This invention discloses a method for preparing silver-loaded stainless steel filter material for polonium capture, relating to the field of radioactive waste gas treatment technology. The method includes the following steps: cleaning a stainless steel substrate and removing the surface oxide layer; depositing a copper coating and a nickel coating on the cleaned stainless steel substrate; depositing a silver coating on the copper and nickel-plated stainless steel substrate; then cleaning and drying the substrate, and finally storing it in an inert environment to obtain the silver-loaded stainless steel filter material for polonium capture. By depositing silver onto the stainless steel surface and employing a process of first depositing a copper coating and a nickel coating, and finally depositing a silver coating, the prepared silver-loaded stainless steel filter material has a high specific surface area, enabling it to selectively capture and purify polonium. This method can be applied to the specific and efficient capture and purification of gaseous polonium in reactors under high-temperature conditions, providing an essential preparation process route for filter materials required for polonium capture and purification in specific nuclear facilities, thus ensuring the operational safety of these facilities.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste gas treatment technology, specifically to a method for preparing silver-loaded stainless steel filter material for polonium capture. Background Technology

[0002] Polonium-210 is an extremely toxic radionuclide that readily forms radioactive aerosols. With a half-life of 138.4 days, it can damage human tissues, organs, and cells, causing DNA damage and cell death if it enters the body. There is a possibility of polonium-210 leakage in certain nuclear facilities, which could have serious impacts on personnel and the environment. The relative concentration of polonium-210 is particularly high in high-temperature environments such as covering gas. The capture and purification of polonium-210 is a critical issue in scenarios such as maintaining negative pressure in the covering gas during normal operation and in situations where leakage of covering gas may occur during accidents.

[0003] Therefore, it is necessary to research and prepare a filter material suitable for capturing polonium-210 in high-temperature gas environments. Furthermore, to possess long-term stable polonium-210 capture and purification capabilities, this filter material needs to meet the following conditions:

[0004] 1. Exhibits long-term stability under high-temperature environments;

[0005] 2. It has a specific and highly efficient ability to capture polonium-210;

[0006] 3. It has good radiation resistance;

[0007] 4. The preparation process is simple, has little environmental impact, and can be mass-produced.

[0008] Patent CN 207883340 U discloses a lead-bismuth reactor radioactive waste purification system with zero radionuclide discharge. This system mainly includes a pre-treatment waste liquid storage module for coagulation treatment of the waste liquid; an inorganic adsorption module connected to the pre-treatment waste liquid storage module for adsorption treatment of the coagulated waste liquid; a primary reverse osmosis module connected to the inorganic adsorption module for preliminary filtration of inorganic salts and organic matter in the adsorbed waste liquid; a reverse osmosis concentrate desalination module connected to both the inorganic adsorption module and the primary reverse osmosis module for desalination of the concentrate from the primary reverse osmosis module before sending it to the inorganic adsorption module; and a secondary reverse osmosis and discharge module connected to both the inorganic adsorption module and the primary reverse osmosis module for further filtration of inorganic salts and organic matter in the waste liquid and discharge of the waste liquid. This invention effectively combines inorganic adsorption, reverse osmosis, and ion exchange desalination technologies to achieve zero radionuclide discharge and zero concentrate generation. The technical solution for adsorbing polonium involves filling a first inorganic adsorption column with a polonium adsorbent, but the specific type of polonium adsorbent used is not disclosed.

[0009] Patent CN 113952845 B discloses a membrane filtration material, its preparation method, and its application in treating aerosols. The preparation method is based on a sol-gel electrospinning and heat treatment process. First, a sol-gel precursor liquid composed of polyvinyl alcohol / tetraethyl orthosilicate / iron salt is prepared. Then, precursor fibers are obtained through electrospinning. Finally, calcination is performed under a reducing atmosphere to remove organic matter and reduce Fe2O3 on the surface of the hybrid fibers to Fe, resulting in a flexible Fe / Fe2O3 / SiO2 hybrid nanofiber membrane. The preparation of this membrane filtration material requires a spinning process, which presents certain challenges.

[0010] Currently, there are no other industrially confirmed and verified technologies for capturing and purifying polonium-210 in the cover gas of lead-cooled fast reactors, either domestically or internationally. Relevant industry literature is limited to the selection and verification of capture materials, including silica, austenitic stainless steel, copper, nickel, platinum, palladium, gold, silver, rare earth elements, etc. No other materials or methods that can specifically capture polonium-210 in high-temperature environments have been reported. Summary of the Invention

[0011] Based on the current practical needs for the capture and purification of gaseous polonium-210 under high-temperature environments and the problem of a lack of capture and purification materials, the purpose of this invention is to provide a method for preparing silver-loaded stainless steel filter material for polonium capture. This method can prepare polonium-210 capture material resistant to high-temperature environments, providing an essential preparation process route for filter materials required for the capture and purification of polonium-210 in specific nuclear facilities, and ensuring the operational safety of specific nuclear facilities.

[0012] This invention is achieved through the following technical solution:

[0013] In a first aspect, this application provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium, comprising the following steps:

[0014] Clean the stainless steel substrate and remove the oxide layer from the surface;

[0015] Copper and nickel coatings are plated onto the cleaned stainless steel substrate.

[0016] A silver coating is deposited on a stainless steel substrate coated with copper and nickel, followed by cleaning and drying, and then stored in an inert environment to obtain a silver-loaded stainless steel filter material for polonium capture.

[0017] The stainless steel used in this invention possesses the ability to capture and purify polonium-210. Simultaneously, silver can selectively react with polonium-210. Using the preparation method of this invention, silver is plated onto the surface of the stainless steel. A process is employed where a copper coating and a nickel coating are first plated, followed by a silver coating. This results in a high specific surface area for the prepared silver-loaded stainless steel filter material, enabling it to selectively capture and purify polonium-210. This allows for the specific and efficient capture and purification of gaseous polonium-210 in reactors under high-temperature conditions. It provides an essential preparation process for filter materials required for the capture and purification of polonium-210 in specific nuclear facilities, ensuring the operational safety of these facilities.

[0018] Furthermore, the stainless steel substrate includes a porous stainless steel mesh or a sintered stainless steel felt.

[0019] Furthermore, when cleaning stainless steel substrates, use soap solution and deionized water to clean, and rinse with ethanol 1 to 3 times to complete the degreasing and cleaning process.

[0020] Furthermore, an acid solution is used to remove the oxide layer on the surface of the stainless steel substrate.

[0021] Furthermore, the acid solution is an aqueous hydrochloric acid solution, and the volume ratio of hydrochloric acid to water in the prepared aqueous hydrochloric acid solution is (4~1):(1~10).

[0022] Furthermore, when plating a copper coating on a stainless steel substrate, a direct current density of 5~12 A / dm is used. 2 Electrodeposition for 60~300s.

[0023] Furthermore, when plating a copper coating on a stainless steel substrate, the electrolytic cell used comprises 10% to 40% by volume of TB33-A electroplating concentrate and 3% to 15% by volume of TB33-B complexing agent.

[0024] Furthermore, when plating a copper coating on a stainless steel substrate, the pH value is set to 7~10 and the temperature is set to 40℃~50℃.

[0025] Furthermore, when plating a nickel coating on a stainless steel substrate, a direct current density of 6~12 A / dm is used. 2 The electrodeposition time is 60~300s.

[0026] Furthermore, when plating a nickel coating on a stainless steel substrate, the electrolytic cell composition includes 100-280 g / L nickel sulfate, 40-60 g / L nickel chloride, and 20-40 g / L boric acid.

[0027] Furthermore, when plating a nickel coating on a stainless steel substrate, the pH is set to 2-6, the pH adjuster used is sulfuric acid (H2SO4), and the temperature is set to 40℃-70℃.

[0028] Furthermore, when plating a silver coating on a stainless steel substrate, a pre-dip silver process is performed first, followed by electroplating.

[0029] Furthermore, the silver immersion solution used for pre-immersion silver contains 5~20g / L silver nitrate and 150~300g / L thiourea.

[0030] Furthermore, the pH during pre-immersion in silver is set to 2-6, the pH adjuster used is nitric acid (HNO3), and the immersion time is 30-100 seconds.

[0031] Furthermore, the electrolyte used in silver electroplating consists of 80-250 g / L sodium thiosulfate, 20-65 g / L silver nitrate, 20-60 g / L K2S2O5, and 0-5 g / L nicotinic acid.

[0032] Furthermore, the pH for silver electroplating is set to 5-10, the pH adjuster used is NaOH / KOH, and the temperature is set to 10℃-45℃.

[0033] Furthermore, during silver electroplating, a pulsed current is used, with the current density set to 0.2~1A / dm². 2 The pulse duty cycle is 20-70%, and the electrodeposition time is 180 seconds.

[0034] Secondly, this application provides a silver-loaded stainless steel filter material for capturing polonium, which is prepared by the above-described preparation method.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] (1) The silver-loaded stainless steel filter material preparation method of the present invention uses stainless steel and silver as raw materials for the preparation of special filter materials, and has long-term stability and radiation resistance in high temperature environment.

[0037] (2) The present invention uses copper and nickel loaded on stainless steel and finally silver loaded on it, so that silver and the substrate have better bonding performance. The silver-loaded stainless steel obtained by pulse electroplating has a large specific surface area structure similar to nanoflowers, so that the silver-loaded filter material has good specific and efficient capture ability for polonium.

[0038] (3) The preparation process of the silver-loaded stainless steel filter material of the present invention is simple, adopts cyanide-free electroplating method, has little environmental pollution, and can be mass-produced. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0040] Figure 1 This is a schematic diagram of the apparatus for plating a copper coating in this invention;

[0041] Figure 2 This is a schematic diagram of the apparatus for plating a nickel coating in this invention;

[0042] Figure 3 This is a schematic diagram of the cyanide-free silver plating device in this invention;

[0043] Figure 4 This is a microscopic surface diagram of the stainless steel after silver plating in Example 1 of the present invention;

[0044] Figure 5 The adsorption capacity and adsorption rate of gaseous tellurium on single-layer porous stainless steel mesh with no silver loading and 1% silver loading at different reaction times are fitted curves.

[0045] Figure 6 The figure shows the fitting curves of the adsorption capacity and adsorption rate of gaseous tellurium on 40-60 mesh stainless steel sintered felt with and without silver loading of 1% silver at different reaction times. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0047] The "scope" disclosed in this application is defined by a lower limit and an upper limit. A given scope is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific scope. A scope defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a scope. Unless otherwise specified, the terms "comprising" and "including" in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that it may also include or include other substances not listed, or it may only include or include the listed substances.

[0048] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0049] Example 1

[0050] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture, which includes the following steps:

[0051] S1. Select stainless steel mesh with an aperture of SSW010 as the base material.

[0052] S2. Clean the substrate with a mild soap solution and deionized water, and rinse with ethanol three times to complete the degreasing and cleaning process.

[0053] S3. Use a 1:1 hydrochloric acid aqueous solution to pickle and remove the oxide layer on the metal surface.

[0054] S4. Prepare the copper plating electrolytic cell: 30% volume fraction of TB33-A electroplating concentrate, 10% volume fraction of TB33-B complexing agent, pH set to 9, and temperature set to 45℃.

[0055] S5, such as Figure 1 As shown, copper plating was performed on the substrate: the DC current density was set to 10 A / dm². 2 Electrodeposition for 180 seconds.

[0056] S6. Configure the nickel plating electrolytic cell: The solution composition is 240 g / L nickel sulfate (NiSO4⋅6H2O), 45 g / L nickel chloride (NiCl2⋅6H2O) and 35 g / L boric acid (H3BO3), the pH is set to 4, the pH adjuster used is sulfuric acid (H2SO4), and the temperature is set to 60℃.

[0057] S7, such as Figure 2 As shown, for nickel plating: the DC current density is set to 10 A / dm². 2 Electrodeposition for 180 seconds.

[0058] S8. Pre-immersion silver operation: Silver immersion solution composition: 15g / L silver nitrate (AgNO3), 250g / L thiourea (CH4N2S), pH set to 4, pH adjuster used is nitric acid (HNO3), immersion time is 60s.

[0059] S9, such as Figure 3As shown, a silver plating electrolytic cell was configured. The silver plating solution consisted of 200 g / L sodium thiosulfate (Na2S2O3), 40 g / L silver nitrate (AgNO3), 45 g / L K2S2O5, and 1.5 g / L nicotinic acid (C6H5NO2). The pH was set to 6, with NaOH used as the pH adjuster. The temperature was set to 25℃, and the pulse current and current density were set to 0.3 A / dm³. 2 The pulse duty cycle was 30%, and the electrodeposition time was 180 seconds.

[0060] S10. After washing with pure water, dry in a dryer at 80°C and store in an inert environment to obtain silver-loaded stainless steel filter media.

[0061] like Figure 4 As shown, the left image is a microscopic surface diagram of the silver-loaded stainless steel filter material prepared using this method, and the right image is a microscopic surface diagram of the filter material at a current density of 0.6 A / dm². 2 The microscopic surface diagram of the silver-loaded stainless steel filter media is shown. It can be seen that the silver-loaded stainless steel filter media prepared according to the examples exposes a large number of silver active sites, which can effectively enhance the contact probability between gaseous polonium and the active sites of the filter media, thereby enhancing the polonium capture performance. In contrast, the surface of the silver-loaded stainless steel filter media not prepared according to the examples tends to be smoother, and the number of active sites is significantly reduced.

[0062] Tellurium, as a group element of polonium, shares chemical similarities. However, polonium lacks stable isotopes and possesses strong ionizing radiation and chemical toxicity, posing significant challenges to safe laboratory operations. Therefore, when verifying the polonium-capturing performance of filter media, tellurium, a group element, is considered as a substitute for polonium. Thus, this application, to verify the polonium-capturing performance of filter media, also uses tellurium instead of polonium, and the test results are as follows:

[0063] like Figure 5 The figure shows the fitted values ​​of the adsorption capacity and adsorption rate of gaseous tellurium on single-layer porous stainless steel mesh with 0% and 1% silver loading at different reaction times. Gas generation temperature: 550 ℃; reaction temperature: 550 ℃; reaction time: 270 min, 390 min, 1440 min. The comparison shows that the adsorption rate and adsorption capacity increase by approximately 1.7 times through this silver-loaded stainless steel preparation method.

[0064] like Figure 6 The figure shows the fitted values ​​of the adsorption capacity and adsorption rate of gaseous tellurium on 40-60 mesh stainless steel sintered felt with 0% and 1% silver loading at different reaction times. Gas generation temperature: 550 ℃; reaction temperature: 550 ℃; reaction time: 270 min, 390 min, 1440 min. The comparison shows that the adsorption rate and adsorption capacity increase by approximately three times using this silver-loaded stainless steel preparation method.

[0065] The two sets of experimental data above demonstrate that the silver-loaded stainless steel filter material can effectively and specifically capture tellurium under high-temperature conditions. Due to the similarity in chemical properties, it also exhibits a positive and effective capture effect on polonium.

[0066] Example 2

[0067] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the stainless steel substrate in this embodiment is a 50-mesh stainless steel sintered felt. Other technical features are the same as in Embodiment 1.

[0068] Example 3

[0069] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. Unlike Embodiment 1, the electrolytic cell used for nickel plating in this embodiment consists of 100 g / L nickel sulfate, 40 g / L nickel chloride, and 40 g / L boric acid. Other technical features are the same as in Embodiment 1.

[0070] Example 4

[0071] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. Unlike Embodiment 1, the electrolytic cell used for nickel plating in this embodiment consists of 280 g / L nickel sulfate, 60 g / L nickel chloride, and 20 g / L boric acid. Other technical features are the same as in Embodiment 1.

[0072] Example 5

[0073] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, in this embodiment, the pH value is 2 and the temperature is set to 40°C during nickel plating. Other technical features are the same as in Embodiment 1.

[0074] Example 6

[0075] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, in this embodiment, the pH value is 6 and the temperature is set to 70°C during nickel plating. Other technical features are the same as in Embodiment 1.

[0076] Example 7

[0077] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the DC current density used during nickel plating in this embodiment is 6 A / dm³. 2 The electrodeposition time was 300 s. Other technical features were the same as in Example 1.

[0078] Example 8

[0079] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the DC current density used during nickel plating in this embodiment is 12 A / dm³. 2 The electrodeposition time was 60 seconds. Other technical features were the same as in Example 1.

[0080] Example 9

[0081] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. The difference from Embodiment 1 is that the silver impregnation solution used in this embodiment consists of 5 g / L silver nitrate and 150 g / L thiourea. Other technical features are the same as in Embodiment 1.

[0082] Example 10

[0083] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. The difference from Embodiment 1 is that the silver impregnation solution used in this embodiment consists of 20 g / L silver nitrate and 300 g / L thiourea. Other technical features are the same as in Embodiment 1.

[0084] Example 11

[0085] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. Unlike Embodiment 1, the pH for pre-impregnation with silver in this embodiment is set to 2, and the pre-impregnation time is 30 seconds. Other technical features are the same as in Embodiment 1.

[0086] Example 12

[0087] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. Unlike Embodiment 1, the pH for pre-impregnation with silver in this embodiment is set to 6, and the pre-impregnation time is 100 seconds. Other technical features are the same as in Embodiment 1.

[0088] Example 13

[0089] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the silver plating solution in this embodiment does not contain nicotinic acid. Other technical features are the same as in Embodiment 1.

[0090] Example 14

[0091] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating solution in this embodiment contains 1 g / L of nicotinic acid. Other technical features are the same as in Embodiment 1.

[0092] Example 15

[0093] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating solution in this embodiment contains 2 g / L of nicotinic acid. Other technical features are the same as in Embodiment 1.

[0094] Example 16

[0095] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating solution in this embodiment contains 3 g / L of nicotinic acid. Other technical features are the same as in Embodiment 1.

[0096] Example 17

[0097] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the silver plating solution in this embodiment contains 4 g / L of nicotinic acid. Other technical features are the same as in Embodiment 1.

[0098] Example 18

[0099] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating solution in this embodiment contains 5 g / L of nicotinic acid. Other technical features are the same as in Embodiment 1.

[0100] Example 19

[0101] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. The difference from Embodiment 1 is that the pH during silver electroplating in this embodiment is set to 5. Other technical features are the same as in Embodiment 1.

[0102] Example 20

[0103] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. The difference from Embodiment 1 is that the pH during silver electroplating in this embodiment is set to 7. Other technical features are the same as in Embodiment 1.

[0104] Example 21

[0105] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. The difference from Embodiment 1 is that the pH during silver electroplating in this embodiment is set to 8. Other technical features are the same as in Embodiment 1.

[0106] Example 22

[0107] This embodiment provides a method for preparing silver-loaded stainless steel filter media for polonium capture. The difference from Embodiment 1 is that the pH during silver electroplating in this embodiment is set to 9. Other technical features are the same as in Embodiment 1.

[0108] Example 23

[0109] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the pH during silver electroplating in this embodiment is set to 10. Other technical features are the same as in Embodiment 1.

[0110] Example 24

[0111] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating temperature in this embodiment is set to 10°C. Other technical features are the same as in Embodiment 1.

[0112] Example 25

[0113] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating temperature in this embodiment is set to 15°C. Other technical features are the same as in Embodiment 1.

[0114] Example 26

[0115] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating temperature in this embodiment is set to 35°C. Other technical features are the same as in Embodiment 1.

[0116] Example 27

[0117] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. The difference from Embodiment 1 is that the silver plating temperature in this embodiment is set to 45°C. Other technical features are the same as in Embodiment 1.

[0118] Example 28

[0119] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the pulse duty cycle during silver electroplating in this embodiment is 40%. Other technical features are the same as in Embodiment 1.

[0120] Example 29

[0121] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the pulse duty cycle during silver electroplating in this embodiment is 50%. Other technical features are the same as in Embodiment 1.

[0122] Example 30

[0123] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the pulse duty cycle during silver electroplating in this embodiment is 60%. Other technical features are the same as in Embodiment 1.

[0124] Example 31

[0125] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the pulse duty cycle during silver electroplating in this embodiment is 70%. Other technical features are the same as in Embodiment 1.

[0126] Example 32

[0127] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the average pulse current during silver electroplating in this embodiment is 0.3 A / dm². 2 Other technical features are the same as in Example 1.

[0128] Example 33

[0129] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the average pulse current during silver electroplating in this embodiment is 0.5 A / dm². 2 Other technical features are the same as in Example 1.

[0130] Example 34

[0131] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the average pulse current during silver electroplating in this embodiment is 0.6 A / dm². 2 Other technical features are the same as in Example 1.

[0132] Example 35

[0133] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the average pulse current during silver electroplating in this embodiment is 0.2 A / dm². 2 Other technical features are the same as in Example 1.

[0134] Example 36

[0135] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for polonium capture. Unlike Embodiment 1, the average pulse current during silver electroplating in this embodiment is 1 A / dm². 2 Other technical features are the same as in Example 1.

[0136] Comparative Example 1

[0137] This comparative example provides a stainless steel filter material for capturing polonium. Unlike Example 1, this comparative example does not undergo silver loading treatment and is carried out using the following steps:

[0138] S1. Select stainless steel mesh with an aperture of SSW010 as the base material.

[0139] S2. Clean the substrate with a mild soap solution and deionized water, and rinse with ethanol three times to complete the degreasing and cleaning process.

[0140] S3. Use a 1:1 hydrochloric acid aqueous solution to pickle and remove the oxide layer on the metal surface.

[0141] S4. Prepare the copper plating electrolytic cell: 30% volume fraction of TB33-A electroplating concentrate, 10% volume fraction of TB33-B complexing agent, pH set to 9, and temperature set to 45℃.

[0142] S5. Perform copper plating on the substrate: set the DC current density to 10A / dm³. 2 Electrodeposition for 180 seconds.

[0143] S6. Configure the nickel plating electrolytic cell: The solution composition is 240 g / L nickel sulfate (NiSO4 •6H2O), 45 g / L nickel chloride (NiCl2 •6H2O) and 35 g / L boric acid (H3BO3), the pH is set to 4, the pH adjuster used is sulfuric acid (H2SO4), and the temperature is set to 60℃.

[0144] S7, Nickel plating: DC current density set to 10A / dm 2 Electrodeposition for 180 seconds.

[0145] S8. After washing with pure water, dry in a dryer at 80°C and store in an inert environment to obtain silver-loaded stainless steel filter media.

[0146] Comparative Example 2

[0147] This comparative example provides a stainless steel filter material for capturing polonium. Unlike Example 1, this comparative example does not involve copper plating; instead, it employs the following steps:

[0148] S1. Select stainless steel mesh with an aperture of SSW010 as the base material.

[0149] S2. Clean the substrate with a mild soap solution and deionized water, and rinse with ethanol three times to complete the degreasing and cleaning process.

[0150] S3. Use a 1:1 hydrochloric acid aqueous solution to pickle and remove the oxide layer on the metal surface.

[0151] S4. Configure the nickel plating electrolytic cell: The solution composition is 240 g / L nickel sulfate (NiSO4 •6H2O), 45 g / L nickel chloride (NiCl2 •6H2O) and 35 g / L boric acid (H3BO3), the pH is set to 4, the pH adjuster used is sulfuric acid (H2SO4), and the temperature is set to 60℃.

[0152] S5, Nickel plating: DC current density set to 10A / dm 2 Electrodeposition for 180 seconds.

[0153] S6. Pre-immersion silver operation: Silver immersion solution composition: 15g / L silver nitrate (AgNO3), 250g / L thiourea (CH4N2S), pH set to 4, pH adjustment agent used is nitric acid (HNO3), immersion time is 60s.

[0154] S7. Configure the silver plating electrolytic cell. The silver plating solution consists of 200 g / L sodium thiosulfate (Na2S2O3), 40 g / L silver nitrate (AgNO3), 45 g / L K2S2O5, and 1.5 g / L nicotinic acid (C6H5NO2). The pH is set to 6, and the pH adjuster used is NaOH / KOH. The temperature is set to 25℃, and the pulse current and current density are set to 0.4 A / dm³. 2 The pulse duty cycle was 30%, and the electrodeposition time was 180 seconds.

[0155] S8. After washing with pure water, dry in a dryer at 80°C and store in an inert environment to obtain silver-loaded stainless steel filter media.

[0156] Comparative Example 3

[0157] This comparative example provides a stainless steel filter material for capturing polonium. Unlike Example 1, this comparative example does not undergo nickel plating and is carried out using the following steps:

[0158] S1. Select stainless steel mesh with an aperture of SSW010 as the base material.

[0159] S2. Clean the substrate with a mild soap solution and deionized water, and rinse with ethanol three times to complete the degreasing and cleaning process.

[0160] S3. Use a 1:1 hydrochloric acid aqueous solution to pickle and remove the oxide layer on the metal surface.

[0161] S4. Prepare the copper plating electrolytic cell: 30% volume fraction of TB33-A electroplating concentrate, 10% volume fraction of TB33-B complexing agent, pH set to 9, and temperature set to 45℃.

[0162] S5. Perform copper plating on the substrate: set the DC current density to 10A / dm³. 2 Electrodeposition for 180 seconds.

[0163] S6. Pre-immersion silver operation: Silver immersion solution composition: 15g / L silver nitrate (AgNO3), 250g / L thiourea (CH4N2S), pH set to 4, pH adjustment agent used is nitric acid (HNO3), immersion time is 60s.

[0164] S7. Configure the silver plating electrolytic cell. The silver plating solution consists of 200 g / L sodium thiosulfate (Na2S2O3), 40 g / L silver nitrate (AgNO3), 45 g / L K2S2O5, and 1.5 g / L nicotinic acid (C6H5NO2). The pH is set to 6, and the pH adjuster used is NaOH / KOH. The temperature is set to 25℃, and the pulse current and current density are set to 0.4 A / dm³. 2 The pulse duty cycle was 30%, and the electrodeposition time was 180 seconds.

[0165] S8. After washing with pure water, dry in a dryer at 80°C and store in an inert environment to obtain silver-loaded stainless steel filter media.

[0166] Comparative Example 4

[0167] This comparative example provides a stainless steel filter material for capturing polonium. Unlike Example 1, this comparative example does not involve nickel or copper plating; instead, silver is directly plated onto the stainless steel mesh using the following steps:

[0168] S1. Select stainless steel mesh with an aperture of SSW010 as the base material.

[0169] S2. Clean the substrate with a mild soap solution and deionized water, and rinse with ethanol three times to complete the degreasing and cleaning process.

[0170] S3. Use a 1:1 hydrochloric acid aqueous solution to pickle and remove the oxide layer on the metal surface.

[0171] S4. Pre-immersion silver operation: Silver immersion solution composition: 15g / L silver nitrate (AgNO3), 250g / L thiourea (CH4N2S), pH set to 4, pH adjustment agent used is nitric acid (HNO3), immersion time is 60s.

[0172] S5. Configure a silver plating electrolytic cell. The silver plating solution consists of 200 g / L sodium thiosulfate (Na2S2O3), 40 g / L silver nitrate (AgNO3), 45 g / L K2S2O5, and 1.5 g / L nicotinic acid (C6H5NO2). The pH is set to 6, and the pH adjuster used is NaOH / KOH. The temperature is set to 25℃, and the pulse current and current density are set to 0.4 A / dm³. 2 The pulse duty cycle was 30%, and the electrodeposition time was 180 seconds.

[0173] S6. After washing with pure water, dry in a dryer at 80°C and store in an inert environment to obtain silver-loaded stainless steel filter media.

[0174] Comparative Example 5

[0175] This comparative example provides a stainless steel filter material for capturing polonium. Unlike Example 1, this comparative example does not undergo a pre-silver impregnation process before silver plating, and instead employs the following steps:

[0176] S1. Select stainless steel mesh with an aperture of SSW010 as the base material.

[0177] S2. Clean the substrate with a mild soap solution and deionized water, and rinse with ethanol three times to complete the degreasing and cleaning process.

[0178] S3. Use a 1:1 hydrochloric acid aqueous solution to pickle and remove the oxide layer on the metal surface.

[0179] S4. Prepare the copper plating electrolytic cell: 30% volume fraction of TB33-A electroplating concentrate, 10% volume fraction of TB33-B complexing agent, pH set to 9, and temperature set to 45℃.

[0180] S5. Perform copper plating on the substrate: set the DC current density to 10A / dm³. 2 Electrodeposition for 180 seconds.

[0181] S6. Configure the nickel plating electrolytic cell: The solution composition is 240 g / L nickel sulfate (NiSO4 •6H2O), 45 g / L nickel chloride (NiCl2 •6H2O) and 35 g / L boric acid (H3BO3), the pH is set to 4, the pH adjuster used is sulfuric acid (H2SO4), and the temperature is set to 60℃.

[0182] S7, Nickel plating: DC current density set to 10A / dm 2 Electrodeposition for 180 seconds.

[0183] S8. Configure a silver plating electrolytic cell. The silver plating solution consists of 200 g / L sodium thiosulfate (Na2S2O3), 40 g / L silver nitrate (AgNO3), 45 g / L K2S2O5, and 1.5 g / L nicotinic acid (C6H5NO2). The pH is set to 6, and the pH adjuster used is NaOH / KOH. The temperature is set to 25℃, and the pulse current and current density are set to 0.4 A / dm³. 2 The pulse duty cycle was 30%, and the electrodeposition time was 180 seconds.

[0184] S9. After washing with pure water, dry in a dryer at 80°C and store in an inert environment to obtain silver-loaded stainless steel filter media.

[0185] Based on the silver-loaded stainless steel substrate prepared by the above embodiments and comparative methods, a series of tellurium adsorption tests were conducted at high temperature using an adsorption testing device to verify the collection and purification performance of the silver-loaded stainless steel prepared by this invention. Comparative results of static and dynamic adsorption tests show that the maximum adsorption capacity of the silver-loaded porous stainless steel mesh prepared by this invention is 1.7 times that of the substrate, and the maximum adsorption capacity of the silver-loaded stainless steel sintered felt prepared by this invention is 3 times that of the substrate. Related experimental data indicate that this silver-loaded stainless steel filter material can effectively and specifically capture tellurium under high-temperature conditions. Due to the similarity of its chemical properties, it also has a positive and effective capture effect on polonium.

[0186] The foregoing description illustrates and describes preferred embodiments of the present invention. As previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for preparing silver-loaded stainless steel filter media for polonium capture, characterized in that, Includes the following steps: Clean the stainless steel substrate and remove the oxide layer from the surface; Copper and nickel coatings are plated onto the cleaned stainless steel substrate. A silver coating is deposited on a stainless steel substrate coated with copper and nickel, then the substrate is cleaned and dried, and then stored in an inert environment to obtain a silver-loaded stainless steel filter material for polonium capture. When plating a silver coating on a stainless steel substrate, a pre-dip silver operation is performed first, followed by electroplating silver. The steps for plating a copper coating include: the copper plating electrolyte is 30% by volume of TB33-A electroplating concentrate and 10% by volume of TB33-B complexing agent, the pH is set to 9, and the temperature is set to 45℃. DC current density set to 10 A / dm 2 Electrodeposition for 180 seconds; The steps for nickel plating include: the nickel plating electrolyte consists of 240 g / L nickel sulfate, 45 g / L nickel chloride and 35 g / L boric acid, the pH is set to 4, the pH adjuster used is sulfuric acid, and the temperature is set to 60℃. DC current density set to 10 A / dm 2 Electrodeposition for 180 seconds; Pre-immersion silver operation: The silver immersion solution consists of 15 g / L silver nitrate and 250 g / L thiourea, with a pH of 4. The pH adjuster used is nitric acid, and the immersion time is 60 seconds. The silver plating process includes using a plating solution of 200 g / L sodium thiosulfate, 40 g / L silver nitrate, 45 g / L K₂S₂O₅, and 1.5 g / L nicotinic acid, with a pH of 6, using NaOH as the pH adjuster, a temperature of 25°C, and a pulse current density of 0.3 A / dm³. 2 The pulse duty cycle was 30%, and the electrodeposition time was 180 seconds.

2. The method for preparing a silver-loaded stainless steel filter material for polonium capture according to claim 1, characterized in that, The stainless steel substrate includes porous stainless steel mesh or stainless steel sintered felt.

3. The method for preparing a silver-loaded stainless steel filter material for polonium capture according to claim 1, characterized in that, When cleaning stainless steel substrates, use soap solution and deionized water to clean, and rinse with ethanol to complete the degreasing and cleaning process.

4. The method for preparing a silver-loaded stainless steel filter material for polonium capture according to claim 1, characterized in that, Use an acid solution to remove the oxide layer from the surface of the stainless steel substrate.

5. A method for preparing a silver-loaded stainless steel filter material for polonium capture according to claim 4, characterized in that, The acid solution is a hydrochloric acid aqueous solution, and the volume ratio of hydrochloric acid to water in the prepared hydrochloric acid aqueous solution is (4~1):(1~10).

6. A silver-loaded stainless steel filter material for capturing polonium, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 5.

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