Preparation method of silver-loaded stainless steel filter material for gathering polonium

Abstract

The invention discloses a preparation method of a silver-loaded stainless steel filter material for gathering polonium, and relates to the technical field of radioactive waste gas treatment.The preparation method comprises the following steps that a stainless steel base material is cleaned, and an oxide layer on the surface of the stainless steel base material is removed; plating a copper coating and a nickel coating on the cleaned stainless steel substrate; and a silver coating is plated on the stainless steel base material plated with copper and nickel, then cleaning and drying treatment is conducted, the stainless steel base material is placed in an inert environment to be stored, and the silver-loaded stainless steel filter material for gathering polonium is obtained. Silver is plated on the surface of stainless steel, and the process method of firstly plating the copper coating and the nickel coating and finally plating the silver coating is adopted, so that the prepared silver-loaded stainless steel filter material is high in specific surface area, has the selective trapping and purifying capacity of polonium, and can be applied to specific efficient trapping and purifying of gaseous polonium under the high-temperature condition; and a necessary preparation process route is provided for the filter material required for trapping and purifying the polonium of the specific nuclear facility, and the operation safety of the specific nuclear facility is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of radioactive waste gas treatment, and in particular to a method for preparing a silver-loaded stainless steel filter material for capturing polonium. Background Art

[0002] Polonium-210 is an extremely toxic radioactive nuclide that easily forms radioactive aerosols of polonium-210 with a half-life of 138.4 days. If it enters the body, it will destroy the cell structure of human tissues and organs, damage DNA and cause cell death. There is a possibility of polonium-210 leakage in specific nuclear facilities, and the leaked polonium-210 may have a serious impact on workers and the environment. Especially in high-temperature environments such as cover gas, the relative concentration of polonium-210 is high. In scenarios such as maintaining negative pressure of the cover gas in normal operating conditions and possible leakage of the cover gas in accident conditions, the capture and purification of polonium-210 is an issue that cannot be ignored.

[0003] Therefore, it is necessary to study and prepare a filter material suitable for capturing polonium-210 in a gas environment at high temperature. In addition, in order to have a long-term and stable polonium-210 capture and purification capability, the filter material needs to meet the following conditions:

[0004] 1. Long-term stability in high temperature environment;

[0005] 2. It has specific and efficient capture capability for polonium-210;

[0006] 3. Good radiation resistance;

[0007] 4. The preparation process is simple, has little harm to the environment, and can be mass-produced.

[0008] Patent CN 207883340 U discloses a lead-bismuth pile radioactive waste liquid purification system with zero nuclide discharge, which mainly includes a pre-waste liquid storage module for coagulation treatment of waste liquid, an inorganic adsorption module connected to the pre-waste liquid storage module for adsorption treatment of waste liquid after coagulation treatment, a primary reverse osmosis module connected to the inorganic adsorption module for preliminary filtration of inorganic salts and organic matter in waste liquid after adsorption treatment, a reverse osmosis concentrated water desalination module connected to the inorganic adsorption module and the primary reverse osmosis module for desalination treatment of concentrated water of the primary reverse osmosis module and then sending it to the inorganic adsorption module, and a secondary reverse osmosis and discharge module connected to the inorganic adsorption module and the primary reverse osmosis module for further filtering inorganic salts and organic matter in waste liquid and discharging waste liquid. The utility model system effectively combines inorganic adsorption, reverse osmosis and ion exchange desalination technologies to achieve a treatment effect of zero nuclide discharge and no concentrated liquid production. The technical solution for adsorbing polonium is to fill 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 filter material, a preparation method thereof, and an application in treating aerosols. The preparation method is based on sol-gel electrospinning and heat treatment processes. First, polyvinyl alcohol / tetraethyl orthosilicate / iron salt is prepared to form a sol-gel precursor liquid, and then the precursor fiber is obtained by electrospinning, and then calcined in a reducing atmosphere to remove organic matter and reduce Fe2O3 on the surface of the hybrid fiber to Fe, thereby obtaining a flexible Fe / Fe2O3 / SiO2 hybrid nanofiber membrane. The membrane filter material needs to adopt a spinning process when preparing it, which has certain preparation difficulties.

[0010] At present, no other industrially confirmed and proven capture and purification technology for polonium-210 in the cover gas of lead-cooled fast reactors has been disclosed at home or abroad. The relevant literature in the industry is limited to the selection and verification of capture materials, including silicon dioxide, austenitic stainless steel, copper, nickel, platinum, palladium, gold, silver, rare earth elements, etc., and no other materials and methods for specific capture of polonium-210 in high-temperature environments have been reported. Summary of the invention

[0011] Based on the actual needs for the capture and purification of gaseous polonium-210 in high-temperature environments and the problem of lack of capture and purification materials, the purpose of the present invention is to provide a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The preparation method can prepare a polonium-210 capture material that is resistant to high-temperature environments, provide the necessary preparation process route for the filter material required for the capture and purification of polonium-210 in specific nuclear facilities, and ensure the safe operation of specific nuclear facilities.

[0012] The present invention is achieved through the following technical solutions:

[0013] In a first aspect, the present 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 on the surface;

[0015] Copper coating and nickel coating are plated on the cleaned stainless steel substrate;

[0016] A silver coating is plated on a stainless steel substrate plated with a copper coating and a nickel coating, and then the substrate is cleaned and dried, and then stored in an inert environment to obtain a silver-loaded stainless steel filter material for capturing polonium.

[0017] The stainless steel used in the present invention has the ability to capture and purify polonium-210, and silver can selectively react with polonium-210. By adopting the preparation method of the present invention, silver is plated on the surface of the stainless steel, and a process method of first plating a copper coating and a nickel coating and finally plating a silver coating is adopted, so that the prepared silver-loaded stainless steel filter material has a high specific surface area, and has the ability to selectively capture and purify polonium-210. It can be used for the specific and efficient capture and purification of gaseous polonium-210 in reactors under high temperature conditions, and provides a necessary preparation process route for the filter material required for the capture and purification of polonium-210 in specific nuclear facilities, thereby ensuring the operation safety of the specific nuclear facilities.

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

[0019] Furthermore, when cleaning the stainless steel substrate, a soap solution and deionized water are used for cleaning, and ethanol is used for rinsing 1 to 3 times to complete the degreasing 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 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).

[0022] Furthermore, when copper coating is plated on a stainless steel substrate, the DC current density used is 5 to 12 A / dm 2 , electrodeposition time 60 to 300 seconds.

[0023] Furthermore, when the copper coating is plated on the 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 the copper coating is plated on the stainless steel substrate, the pH value is set to 7-10 and the temperature is set to 40°C-50°C.

[0025] Furthermore, when the nickel coating is plated on the stainless steel substrate, the DC current density used is 6 to 12 A / dm 2 , the electrodeposition time is 60 to 300 s.

[0026] Furthermore, when the nickel coating is plated on the stainless steel substrate, the electrolytic cell used comprises 100-280 g / L nickel sulfate, 40-60 g / L nickel chloride, and 20-40 g / L boric acid.

[0027] Furthermore, when the nickel coating is plated on the stainless steel substrate, the pH is set to 2-6, the pH regulator used is sulfuric acid (H2SO4), and the temperature is set to 40°C-70°C.

[0028] Furthermore, when the silver coating is plated on the stainless steel substrate, a pre-silvering operation is first performed, and then the silver electroplating is performed.

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

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

[0031] Furthermore, the electrolyte used in the silver electroplating comprises 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 during silver electroplating is set to 5-10, the pH regulator used is NaOH / KOH, and the temperature is set to 10°C-45°C.

[0033] Furthermore, during silver electroplating, a pulse current is used, wherein the current density is set to 0.2 to 1 A / dm 2 , the pulse duty cycle is 20-70%, and the electrodeposition is 180s.

[0034] In a second aspect, the present application provides a silver-loaded stainless steel filter material for capturing polonium, which is prepared using the above-mentioned preparation method.

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

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

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

[0038] (3) The silver-loaded stainless steel filter material preparation method of the present invention has a simple preparation process, adopts a cyanide-free electroplating method, has little pollution to the environment, and can be mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0040] Figure 1 It is a schematic diagram of a device for plating a copper coating in the present invention;

[0041] Figure 2 Schematic diagram of a device for plating nickel coating in the present invention;

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

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

[0044] Figure 5 The adsorption amount and adsorption rate fitting curve of gaseous tellurium on a single-layer porous stainless steel mesh without silver or with 1% silver at different reaction times;

[0045] Figure 6 The figure is a fitting curve diagram of the adsorption amount and adsorption rate of gaseous tellurium by 40-60 mesh stainless steel sintered felt without silver or with 1% silver at different reaction times. DETAILED DESCRIPTION

[0046] In order to make the purpose, 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 only part of the embodiments of the present invention, rather than all the embodiments.

[0047] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can include or exclude end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. If there is no special explanation, the "including" and "comprising" mentioned in the present application represent open-ended or closed-ended. For example, the "including" and "comprising" can represent that other substances not listed can also be included or included, or only listed substances can be included or included.

[0048] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium, which is carried out by the following steps:

[0051] S1. Select a stainless steel mesh with a pore size of SSW010 as the substrate.

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

[0053] S3. Use a hydrochloric acid aqueous solution with a volume ratio of 1:1 for pickling to remove the oxide layer on the metal surface.

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

[0055] S5, such as Figure 1 As shown, copper plating is performed on the substrate: the DC current density is set to 10A / dm 2 , electrodeposition for 180s.

[0056] S6. Prepare a nickel plating electrolytic cell: the solution composition is 240g / L nickel sulfate (NiSO4·6H2O), 45g / L nickel chloride (NiCl2·6H2O) and 35g / 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°C.

[0057] S7, such as Figure 2 As shown, nickel plating: DC current density is set to 10A / dm 2 , electrodeposition for 180s.

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

[0059] S9, such as Figure 3As shown, a silver plating electrolytic cell is configured, the silver plating solution is 200g / L sodium thiosulfate (Na2S2O3), 40g / L silver nitrate (AgNO3), 45g / L K2S2O5, 1.5g / L nicotinic acid (C6H5NO2), the pH is set to 6, the pH regulator used is NaOH, the temperature is set to 25°C, the pulse current and current density are set to 0.3A / dm 2 , the pulse duty cycle was 30%, and the electrodeposition was 180s.

[0060] S10, after washing with pure water, drying in a dryer at 80°C, and storing in an inert environment to obtain a silver-loaded stainless steel filter material.

[0061] like Figure 4 As shown, the left picture is the microscopic surface picture of the silver-loaded stainless steel filter material prepared by this method, and the right picture is the current density of 0.6A / dm 2 , the surrounding surface of the silver-loaded stainless steel filter material. It can be seen that the silver-loaded stainless steel filter material prepared based on the embodiment exposes a large silver active site, which can effectively enhance the contact probability between gaseous polonium and the active site of the filter material and enhance the polonium capture performance. However, the surface of the silver-loaded stainless steel filter material not prepared according to the embodiment tends to be flat, and the active sites are significantly reduced.

[0062] Tellurium, as a homologue of polonium, is chemically similar. Based on this, the IPPE Research Center in Obninsk, Russian Federation and the Massachusetts Institute of Technology in the United States successfully conducted alkaline extraction tests using tellurium as a substitute for polonium. Since polonium has no stable isotopes and has strong ionizing radiation and chemical toxicity, it brings great inconvenience to laboratory safety operations. When verifying the capture performance of the filter material for polonium, consider replacing polonium with tellurium, a homologue of the same family. Therefore, in order to verify the capture performance of the filter material for polonium, this application also uses tellurium, a homologue of the same family, to replace polonium. The test results are as follows:

[0063] like Figure 5 As shown in the figure, the adsorption amount and adsorption rate of gaseous tellurium by single-layer porous stainless steel mesh loaded with 0% and 1% silver at different reaction times are fitted. Gas generation temperature: 550℃; reaction temperature: 550℃; reaction time: 270min, 390min, 1440min. By comparison, it can be seen that the adsorption rate and adsorption amount increased by about 1.7 times through the preparation method of silver-loaded stainless steel.

[0064] like Figure 6 As shown in the figure, the adsorption amount and adsorption rate of 0% and 1% silver-loaded 40-60 mesh stainless steel sintered felt for gaseous tellurium are fitted at different reaction times. Gas generation temperature: 550℃; reaction temperature: 550℃; reaction time: 270min, 390min, 1440min. By comparison, it can be seen that the adsorption rate and adsorption amount are increased by about 3 times through the preparation method of silver-loaded stainless steel.

[0065] The above two sets of test data show that the silver-loaded stainless steel filter material can effectively and specifically capture tellurium in a high temperature environment. Due to the similarity of chemical properties, it also has 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 capturing polonium. The difference from Embodiment 1 is that the stainless steel substrate in this embodiment is a 50-mesh stainless steel sintered felt. Other technical features are the same as those in Embodiment 1.

[0068] Example 3

[0069] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Example 1 is that when the nickel coating is plated in this embodiment, the electrolytic cell composition used is 100 g / L nickel sulfate, 40 g / L nickel chloride, and 40 g / L boric acid. Other technical features are the same as those of Example 1.

[0070] Example 4

[0071] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Example 1 is that when the nickel coating is plated in this embodiment, the electrolytic cell composition used is 280 g / L nickel sulfate, 60 g / L nickel chloride, and 20 g / L boric acid. Other technical features are the same as those of Example 1.

[0072] Example 5

[0073] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that when the nickel coating is plated in this embodiment, the pH value is 2 and the temperature is set to 40° C. The other technical features are the same as those in Embodiment 1.

[0074] Example 6

[0075] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that when the nickel coating is plated in this embodiment, the pH value is 6 and the temperature is set to 70° C. The other technical features are the same as those in Embodiment 1.

[0076] Example 7

[0077] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Example 1 is that the DC current density used during nickel plating in this embodiment is 6A / dm 2 , the electrodeposition time is 300s. Other technical features are the same as those in Example 1.

[0078] Example 8

[0079] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Example 1 is that the DC current density used during nickel plating in this embodiment is 12A / dm 2 , the electrodeposition time is 60s. Other technical features are the same as those in Example 1.

[0080] Example 9

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

[0082] Example 10

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

[0084] Embodiment 11

[0085] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that the pH value of this embodiment during pre-immersion of silver is set to 2, and the pre-immersion time is 30 seconds. Other technical features are the same as those of Embodiment 1.

[0086] Example 12

[0087] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that the pH value of this embodiment during pre-immersion of silver is set to 6, and the pre-immersion time is 100 seconds. Other technical features are the same as those of Embodiment 1.

[0088] Embodiment 13

[0089] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that the silver plating solution of this embodiment does not contain nicotinic acid. Other technical features are the same as those of Embodiment 1.

[0090] Embodiment 14

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

[0092] Embodiment 15

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

[0094] Example 16

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

[0096] Embodiment 17

[0097] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that the silver plating solution of this embodiment contains 4 g / L of nicotinic acid. Other technical features are the same as those of Embodiment 1.

[0098] Embodiment 18

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

[0100] Embodiment 19

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

[0102] Embodiment 20

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

[0104] Embodiment 21

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

[0106] Embodiment 22

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

[0108] Embodiment 23

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

[0110] Embodiment 24

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

[0112] Embodiment 25

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

[0114] Embodiment 26

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

[0116] Embodiment 27

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

[0118] Embodiment 28

[0119] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium, which is different from the first embodiment in that the pulse duty ratio of the silver electroplating in this embodiment is 40%. Other technical features are the same as those in the first embodiment.

[0120] Embodiment 29

[0121] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium, which is different from the first embodiment in that the pulse duty ratio of the silver electroplating in this embodiment is 50%. Other technical features are the same as those in the first embodiment.

[0122] Embodiment 30

[0123] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium, which is different from the first embodiment in that the pulse duty ratio of the silver electroplating in this embodiment is 60%. Other technical features are the same as those in the first embodiment.

[0124] Embodiment 31

[0125] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium, which is different from the embodiment 1 in that the pulse duty ratio during silver electroplating in this embodiment is 70%. Other technical features are the same as those in the embodiment 1.

[0126] Embodiment 32

[0127] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that the average pulse current during silver electroplating in this embodiment is 0.3A / dm 2 . Other technical features are the same as those of Example 1.

[0128] Embodiment 33

[0129] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Example 1 is that the average pulse current during silver electroplating in this embodiment is 0.5A / dm 2 . Other technical features are the same as those of Example 1.

[0130] Embodiment 34

[0131] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Example 1 is that the average pulse current during silver electroplating in this embodiment is 0.6A / dm 2 . Other technical features are the same as those of Example 1.

[0132] Embodiment 35

[0133] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Embodiment 1 is that the average pulse current during silver electroplating in this embodiment is 0.2A / dm 2 . Other technical features are the same as those of Example 1.

[0134] Embodiment 36

[0135] This embodiment provides a method for preparing a silver-loaded stainless steel filter material for capturing polonium. The difference from Example 1 is that the average pulse current during silver electroplating in this embodiment is 1A / dm 2 . Other technical features are the same as those of 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 is not subjected to silver loading treatment, and the following steps are used:

[0138] S1. Select a stainless steel mesh with a pore size of SSW010 as the substrate.

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

[0140] S3. Use a hydrochloric acid aqueous solution with a volume ratio of 1:1 for pickling to remove the oxide layer on the metal surface.

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

[0142] S5. Implement copper plating on the substrate: the DC current density is set to 10A / dm 2 , electrodeposition for 180s.

[0143] S6. Prepare a nickel plating electrolytic cell: the solution composition is 240g / L nickel sulfate (NiSO4·6H2O), 45g / L nickel chloride (NiCl2·6H2O) and 35g / 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°C.

[0144] S7, nickel plating: DC current density is set to 10A / dm 2 , electrodeposition for 180s.

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

[0146] Comparative Example 2

[0147] This comparative example provides a stainless steel filter material for capturing polonium. Unlike Example 1, this comparative example is not subjected to copper plating treatment, and the following steps are used:

[0148] S1. Select a stainless steel mesh with a pore size of SSW010 as the substrate.

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

[0150] S3. Use a hydrochloric acid aqueous solution with a volume ratio of 1:1 for pickling to remove the oxide layer on the metal surface.

[0151] S4. Configure a nickel plating electrolytic cell: the solution composition is 240g / L nickel sulfate (NiSO4·6H2O), 45g / L nickel chloride (NiCl2·6H2O) and 35g / 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°C.

[0152] S5, nickel plating: DC current density is set to 10A / dm 2 , electrodeposition for 180s.

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

[0154] S7. Prepare a silver plating electrolytic cell. The silver plating solution is 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. The pH adjuster used is NaOH / KOH. The temperature is set to 25°C. The pulse current and current density are set to 0.4 A / dm 2 , the pulse duty cycle was 30%, and the electrodeposition was 180s.

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

[0156] Comparative Example 3

[0157] This comparative example provides a stainless steel filter material for capturing polonium. Unlike Example 1, this comparative example is not nickel-plated, and the following steps are used:

[0158] S1. Select a stainless steel mesh with a pore size of SSW010 as the substrate.

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

[0160] S3. Use a hydrochloric acid aqueous solution with a volume ratio of 1:1 for pickling to remove the oxide layer on the metal surface.

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

[0162] S5. Implement copper plating on the substrate: the DC current density is set to 10A / dm 2 , electrodeposition for 180s.

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

[0164] S7. Prepare a silver plating electrolytic cell. The silver plating solution is 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. The pH adjuster used is NaOH / KOH. The temperature is set to 25°C. The pulse current and current density are set to 0.4 A / dm 2 , the pulse duty cycle was 30%, and the electrodeposition was 180s.

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

[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 undergo nickel plating and copper plating, but directly silver-plating the stainless steel mesh, using the following steps:

[0168] S1. Select a stainless steel mesh with a pore size of SSW010 as the substrate.

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

[0170] S3. Use a hydrochloric acid aqueous solution with a volume ratio of 1:1 for pickling to remove the oxide layer on the metal surface.

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

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

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

[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 perform a pre-silvering operation before silver plating, and adopts the following steps:

[0176] S1. Select a stainless steel mesh with a pore size of SSW010 as the substrate.

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

[0178] S3. Use a hydrochloric acid aqueous solution with a volume ratio of 1:1 for pickling to remove the oxide layer on the metal surface.

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

[0180] S5. Implement copper plating on the substrate: the DC current density is set to 10A / dm 2 , electrodeposition for 180s.

[0181] S6. Prepare a nickel plating electrolytic cell: the solution composition is 240g / L nickel sulfate (NiSO4·6H2O), 45g / L nickel chloride (NiCl2·6H2O) and 35g / 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°C.

[0182] S7, nickel plating: DC current density is set to 10A / dm 2 , electrodeposition for 180s.

[0183] S8. Prepare a silver plating electrolytic cell. The silver plating solution is 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. The pH adjuster used is NaOH / KOH. The temperature is set to 25°C. The pulse current and current density are set to 0.4 A / dm 2 , the pulse duty cycle was 30%, and the electrodeposition was 180s.

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

[0185] Based on the silver-loaded stainless steel with a stainless steel matrix prepared by the above embodiments and comparative examples, a series of tellurium adsorption tests were carried out in a high temperature environment using an adsorption test device to verify the capture and purification performance of the silver-loaded stainless steel prepared by the present invention. The comparative test results of static and dynamic adsorption show that the maximum adsorption capacity of the silver-loaded porous stainless steel mesh prepared by the present invention is 1.7 times that of the matrix, and the maximum adsorption capacity of the silver-loaded stainless steel sintered felt prepared by the present invention is 3 times that of the matrix. Relevant test data show that the silver-loaded stainless steel filter material can effectively and specifically capture tellurium in a high temperature environment. Due to the similarity of chemical properties, it also has a positive and effective capture effect on polonium.

[0186] The above description shows and describes the preferred embodiments of the present invention. As mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a silver-loaded stainless steel filter material for capturing polonium, characterized in that: The following steps are involved: Clean the stainless steel substrate and remove the oxide layer on the surface; Copper coating and nickel coating are plated on the cleaned stainless steel substrate; A silver coating is plated on a stainless steel substrate plated with a copper coating and a nickel coating, and then the substrate is cleaned and dried, and then stored in an inert environment to obtain a silver-loaded stainless steel filter material for capturing polonium.

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

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

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

5. The method for preparing a silver-loaded stainless steel filter material for capturing polonium 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. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 1, characterized in that: When copper coating is plated on stainless steel substrate, the DC current density used is 5 to 12A / dm 2 , electrodeposition time 60 to 300 seconds.

7. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 1, characterized in that: When copper coating is plated on a stainless steel substrate, the composition of the electrolytic cell used includes 10%-40% by volume of TB33-A electroplating concentrate and 3%-15% by volume of TB33-B complexing agent.

8. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 1, characterized in that: When copper coating is plated on stainless steel substrate, the pH value is set to 7-10 and the temperature is set to 40℃~50℃.

9. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 1, characterized in that: When nickel coating is applied to stainless steel substrate, the DC current density used is 6-12A / dm 2 , the electrodeposition time is 60 to 300 s.

10. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 1, characterized in that: When a nickel coating is plated on a stainless steel substrate, the electrolytic cell used comprises 100-280 g / L nickel sulfate, 40-60 g / L nickel chloride, and 20-40 g / L boric acid.

11. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 1, characterized in that: When nickel coating is plated on a stainless steel substrate, the pH is set to 2-6 and the temperature is set to 40°C-70°C.

12. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 1, characterized in that: When silver coating is plated on stainless steel substrate, pre-silvering operation is performed first, and then silver electroplating is performed.

13. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 12, characterized in that: The components of the silver immersion solution used for pre-silver immersion include 5-20 g / L silver nitrate and 150-300 g / L thiourea.

14. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 12, characterized in that: The pH value during pre-silver immersion is set to 2-6, and the silver immersion time is 30-100s.

15. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 12, characterized in that: The components of the electrolyte used in silver electroplating include 80-250 g / L sodium thiosulfate, 20-65 g / L silver nitrate, 20-60 g / L K2S2O5, and 0-5 g / L nicotinic acid.

16. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 12, characterized in that: The pH value during silver electroplating is set to 5-10, and the temperature is set to 10°C-45°C.

17. The method for preparing a silver-loaded stainless steel filter material for capturing polonium according to claim 12, characterized in that: When electroplating silver, a pulse current is used, where the current density is set to 0.2 to 1 A / dm 2 , the pulse duty cycle is 20-70%, and the electrodeposition is 180s.

18. A silver-loaded stainless steel filter material for capturing polonium, characterized in that: The preparation method is described in any one of claims 1 to 17.

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