Neutron radiation-proof glass and preparation method thereof

Abstract

The present invention discloses a neutron radiation-proof glass and a preparation method thereof. The neutron radiation-proof glass comprises, by weight, the following components: SiO2: 0.5-3.5%; B2O3: 20.0-35.0%; Li2O: 0.5-9.0%; Na2O: 0.1-5.0%; Gd2O3: 31.0-40.0%; Y2O3: 11.0-19.0%; GeO2: 0.1-9.0%; Nb2O5: 0.1-5.0%; ZnO: 0.5-5.0%; CeO2: 1.0-9.0%; WO3: 0.5-5.0%; and In2O3: 1.0-2.0%. By rationally configuring the components and their contents, the present invention achieves a 550nm transmittance greater than 80% and a Knoop hardness greater than 600×10 7 MPa, the glass thickness required to reduce the neutron dose rate to 50% is less than 30 mm, and the neutron radiation-proof glass of the present invention can effectively protect against neutron radiation. The obtained neutron radiation-proof glass has good radiation protection, glass forming properties, and chemical stability, and the optical uniformity of the neutron radiation-proof glass can reach 5×10 ‑6 , it is easy to prepare large-sized and highly uniform neutron radiation-proof glass.

Description

Technical Field

[0001] The present invention relates to the field of special glass materials, in particular to neutron radiation-proof glass and a preparation method thereof, belonging to the technical field of glass materials. Background Art

[0002] With the development of science and technology, neutron detection has been widely used in nuclear reactor devices, aerospace, radiological medical examinations, national defense and military, cosmic ray detection, environmental radiation detection, material testing and other fields, making neutron radiation-proof glass a protective product needed for military, civilian, scientific research, etc.

[0003] Neutrons are electrically neutral particles, unaffected by the Coulomb force between the nucleus and extranuclear electrons. There are three types: thermal, slow, and fast neutrons. Neutrons are highly penetrating, necessitating specialized protective measures. Neutron-shielding glass effectively blocks neutrons and is widely used in a variety of nuclear radiation environments, including nuclear research viewing and protective windows, nuclear power plant viewing windows, optical instrument panels and lenses in nuclear radiation environments, space exploration protective panels, and nuclear medicine protection. It plays a vital role in nuclear applications and is an indispensable optical glass material. However, most current radiation-shielding glass contains high levels of PbO, leading to serious heavy metal contamination during its preparation and application. Alternatively, PbO-free radiation-shielding glass can only protect against low-energy radiation, such as gamma rays, and its protection against highly penetrating neutrons or high-dose neutron fluxes falls far short of the required level. Summary of the Invention

[0004] In order to overcome the problems existing in the prior art, the purpose of the present invention is to provide a neutron radiation-proof glass. The present invention also provides a method for preparing the neutron radiation-proof glass.

[0005] To solve the above technical problems, the present invention adopts the following technical solution: a neutron radiation-proof glass, characterized in that it is prepared from the following oxides in accordance with mass percentage (wt.%):

[0006]

[0007] Furthermore, the neutron radiation shielding glass of the present invention is characterized in that it is prepared from the following oxides in accordance with mass percentage (wt.%):

[0008]

[0009] Furthermore, the neutron radiation shielding glass of the present invention is characterized in that it is prepared from the following oxides in accordance with mass percentage (wt.%):

[0010]

[0011] The present invention also provides a method for preparing neutron radiation-proof glass, which is characterized by comprising the following steps:

[0012] Relevant raw materials are weighed according to glass components, mixed evenly and placed in a platinum crucible, and then melted, stirred, formed and annealed at high temperature to obtain the neutron radiation-proof glass.

[0013] The melting process is to place the raw materials after uniform mixing at 1400-1500° C. and melt them for 6-8 hours to form a glass melt.

[0014] The stirring process involves stirring the glass melt with a platinum stirrer until a clear, homogenized glass liquid is formed after the glass melt is formed into a molten glass body. The stirring speed is 30-45 rpm and the stirring time is 2-4 hours. During the entire stirring process, oxygen is introduced into the glass melt at a flow rate of 0.3-0.5 L / min to ensure an oxygen-rich state during the stirring and homogenization of the glass melt.

[0015] The forming process is a process of cooling the glass melt to 1250-1350°C and then pouring it into a heat-resistant steel mold preheated to 500-600°C for forming.

[0016] The annealing temperature is 650-710° C., the annealing time is 8-10 hours, and then the product is cooled to room temperature in the furnace.

[0017] In addition, the present invention also provides an application of the above-mentioned neutron radiation-proof glass or the neutron radiation-proof glass prepared by the above-mentioned preparation method in neutron radiation protection and observation windows in nuclear reactor devices, aerospace, radiomedical examination, national defense and military, cosmic ray detection, environmental radiation detection, material detection, etc.

[0018] Compared with the prior art, the neutron radiation-proof glass provided by the present invention has the following significant advantages:

[0019] 1. The neutron radiation-proof glass prepared by the present invention does not contain any of the metal oxides harmful to the environment, such as As2O3, Sb2O3, BaO, PbO, Tl2O, CdO, BeO, V2O5, etc., and is not likely to cause harm to the environment and human body, and is an environmentally friendly glass.

[0020] 2. The present invention has achieved a transmittance of more than 80% at 550nm and a Knoop hardness of more than 600 (×10 7 MPa).

[0021] 3. The thickness of the glass of the present invention required to reduce the neutron dose rate to 50% is less than 30 mm, which can effectively protect against fast neutrons.

[0022] 4. The present invention rationally configures the components and their contents to obtain neutron radiation-proof glass with good radiation protection, glass forming properties and chemical stability. The optical uniformity of the neutron radiation-proof glass can reach 5×10 -6 .

[0023] 5. The components provided by the present invention are easy to prepare large-sized and highly uniform neutron radiation-proof glass. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention are described in further detail below.

[0025] The present invention will be further described in detail below with reference to specific embodiments, but this is not intended to limit the present invention.

[0026] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all conventional reagents that can be purchased on the market.

[0027] The present invention provides a neutron radiation-proof glass, characterized in that it is prepared from the following oxides in accordance with mass percentage (wt.%):

[0028]

[0029]

[0030] Furthermore, the neutron radiation shielding glass of the present invention is characterized in that it is prepared from the following oxides in accordance with mass percentage (wt.%):

[0031]

[0032] Furthermore, the neutron radiation shielding glass of the present invention is characterized in that it is prepared from the following oxides in accordance with mass percentage (wt.%):

[0033]

[0034]

[0035] In the neutron radiation-proof glass provided by the present invention, SiO2 is the main component that forms the skeleton structure of the glass and is the main component in the glass skeleton. It can improve the glass-forming ability and chemical stability of the glass, but its excessive use will increase the melting temperature of the glass, bringing difficulties to the melting and forming operation. The mass percentage (wt.%) of SiO2 in the present invention is controlled to be 0.5-3.5, preferably 2.0-3.5. When the SiO2 content is lower than 0.5wt.%, the glass-forming ability and chemical properties of the glass will deteriorate, and the chemical resistance and mechanical strength of the glass will be reduced; when the SiO2 content is higher than 3.5wt.%, the high-temperature viscosity of the glass will increase, resulting in an excessively high glass melting temperature, and the radiation-proof ability of the glass will deteriorate.

[0036] B2O3 is a glass-forming oxide and a component of the glass skeleton. It is also an excellent neutron absorber with a large neutron capture cross section, a wide absorption energy spectrum, and excellent corrosion resistance. It is a necessary component for the neutron radiation-proof glass of the present invention to have radiation protection capabilities. 10 B has the characteristic of high absorption of neutrons, so in order to better prevent neutron radiation, the present invention uses 10 B replaces B in the formula. The mass percentage (wt.%) of B2O3 is 20-35, preferably 25-35. A B2O3 content below 20 wt.% will impair the radiation protection of the glass and make it difficult to meet the application requirements of neutron radiation. A B2O3 content greater than 35 wt.% will reduce the chemical stability and mechanical strength of the glass.

[0037] Li2O is an oxide outside the glass network and an excellent neutron absorber. It can reduce the viscosity of glass, making it easier to melt. The weight percentage (wt.%) of Li2O is 0.5-9.0, preferably 2.5-5.0. A Li2O content below 0.5% increases the melt viscosity of the glass; a Li2O content greater than 9.0% reduces the glass's devitrification resistance and glass transition temperature.

[0038] Na2O is an oxide outside the glass network. The mass percentage (wt.%) of Na2O is 0.1-5.0, preferably 0.6-1.0. A Na2O content below 0.1% increases the melt viscosity of the glass; a Na2O content greater than 5.0% decreases the transition temperature and chemical stability of the glass.

[0039] Gd2O3, an oxide with a high absorption cross-section, attenuates neutrons by capturing them. The Gd2O3 content ranges from 31.0 to 40.0 wt.%. Below 31.0 wt.%, the radiation shielding capability of the glass deteriorates, making it difficult to meet the requirements of specialized environments. Above 40.0 wt.%, the glass's glass-forming properties and devitrification resistance decrease, making it difficult to form a homogeneous glass melt.

[0040] Y2O3 is an essential component for neutron-shielding glass to have good elastic modulus and chemical stability, and it can improve the glass's chemical resistance. The Y2O3 content (wt.%) ranges from 11.0 to 19.0, preferably from 11.0 to 15.0. Y2O3 contents below 11.0 wt.% do not significantly improve the glass's chemical resistance. Y2O3 contents above 19.0 wt.% increase the glass's thermal expansion coefficient, reducing its glassiness and transmittance.

[0041] GeO2 is an important network former in neutron-proof glass, improving its glass-forming ability and chemical stability. It also serves as a good clarifier, helping to eliminate bubbles. It also has excellent radiation resistance, preventing devitrification in radiation-resistant environments. The mass percentage (wt.%) of GeO2 is 0.1-9.0, preferably 5.0-9.0. A GeO2 content below 0.1wt.% will impair the glass's glass-forming properties; a GeO2 content above 9.0wt.% will increase the glass's tendency to crystallize and impair its chemical stability.

[0042] Nb2O5 is a component that contributes to the excellent elastic modulus of neutron-shielding glass. In the present invention, the Nb2O5 content is controlled within a range of 0.1-5.0% by weight, preferably 1.0-3.0%. When the Nb2O5 content is less than 0.1% by weight, the chemical stability of the glass is significantly reduced. When the Nb2O5 content is greater than 5.0% by weight, the Nb2O5 is difficult to fully melt in the glass, making it difficult to form a homogeneous glass melt, and the glass's glass-forming properties and transmittance are also reduced.

[0043] ZnO is a glass intermediate oxide with excellent chemical stability. The weight percentage (wt%) of ZnO is 0.5-5, preferably 0.6-4. A ZnO content below 0.5 wt% does not significantly improve the chemical stability of the glass. A ZnO content greater than 5 wt% increases the tendency of the glass to separate and reduces its transmittance.

[0044] CeO2 mainly acts as a clarifier and radiation resistant agent, which can prevent the glass from losing transparency in a radiation environment. The mass percentage (wt.%) of CeO2 is 1.0-9.0. If the CeO2 content is lower than 1.0wt.%, it cannot have a stabilizing effect. If the CeO2 content is higher than 9.0wt.%, the transmittance of the glass will be reduced.

[0045] WO3 is an essential component of the neutron radiation-proof glass of the present invention, which can improve the glass's ability to absorb neutron rays. The mass percentage (wt.%) of WO3 is 0.5-5. When the WO3 content is lower than 0.5wt.%, the glass's ability to protect against neutron radiation deteriorates; when the WO3 content is greater than 5wt.%, the glass's glassiness deteriorates and the glass's tendency to crystallize increases.

[0046] In2O3 is a component of neutron-shielding glass with a high transition temperature and chemical stability, enhancing its ability to absorb neutron radiation. The mass percentage (wt.%) of In2O3 is controlled to be 1.0-2.0%. If the In2O3 content is less than 1.0 wt.%, the glass's neutron shielding ability deteriorates, making it difficult to meet the requirements of specialized environments. If the In2O3 content exceeds 2.0 wt.%, the glass's glassability deteriorates, making it difficult to form a homogeneous body.

[0047] The neutron radiation shielding glass of the present invention does not contain any of the environmentally harmful metal oxides such as As2O3, Sb2O5, BaO, PbO, Tl2O, CdO, BeO, V2O5, etc. Even if a very small amount is contained, it is introduced by other glass raw materials.

[0048] Furthermore, the neutron radiation-proof glass is characterized in that the transmittance at 550nm is greater than 80%, the Knoop hardness is greater than 600 (×10 7 MPa).

[0049] Furthermore, the neutron radiation-proof glass is characterized in that the thickness of the glass required for reducing the neutron dose rate to 50% is less than 30 mm, and the neutron radiation-proof glass can effectively protect against fast neutrons.

[0050] Furthermore, the neutron radiation-proof glass is characterized in that: by rationally configuring the components and their contents, the neutron radiation-proof glass obtained has good radiation protection, glass forming properties, and chemical stability, and the optical uniformity of the neutron radiation-proof glass can reach 5×10 -6 .

[0051] Furthermore, the neutron radiation-proof glass is characterized in that the components provided by the present invention are easy to prepare large-sized and highly uniform neutron radiation-proof glass.

[0052] The parameters, measuring methods, and instruments measured for the neutron radiation shielding glass of the present invention are as follows:

[0053] (1) Test method for transmittance of neutron radiation-proof glass: Test in accordance with the method of GB / T 2680-1994 “Determination of visible light transmittance, direct solar transmittance, total solar transmittance, ultraviolet transmittance and related window glass parameters for building glass”.

[0054] (2) Test method for transition temperature of neutron radiation-proof glass: Test according to the method of GB / T 7962.16-2010 "Test methods for colorless optical glass Part 16: Linear expansion coefficient, transition temperature and sag temperature".

[0055] (3) Test method for optical uniformity of neutron radiation-proof glass: Test according to the method of GB / T 7962.2-2010 "Test methods for colorless optical glass Part 2: Optical uniformity - Fizeau plane interferometry".

[0056] (4) Test method for water resistance stability of neutron radiation proof glass: Test according to the method of GB / T 12416.2-1990 “Test method and classification of water resistance of glass particles at 121°C”.

[0057] (5) Test method for acid resistance of radiation-proof glass: Test with reference to the method of GB / T 15728-1995 "Gravimetric test method and classification of resistance of glass to boiling hydrochloric acid".

[0058] (6) Thickness of the glass of the present invention required to reduce the neutron dose rate to 50%: After irradiating neutron-shielding glasses of the present invention with different thicknesses at a 0.3 MeV neutron source, the thickness of the glass required to reduce the neutron dose rate to 50% was tested. The test showed that the thickness of the glass of the present invention required to reduce the neutron dose rate to 50% was 29-30 mm.

[0059] (7) Knoop hardness (×10 7 MPa) testing method: The sample of the present invention is prepared into a block of 20×20×20 mm, the surface is polished, and a square pyramid diamond indenter with symmetrical angles of 172°30′ and 13° is used to apply a certain load vertically to the sample surface. After a certain period of time, the load is removed, and the length of the long diagonal line of the indentation on the sample is observed and measured under a microscope. The projected area of ​​the indentation is converted to calculate the Knoop hardness. After testing, the Knoop hardness range is 610-620 (×10 7 MPa).

[0060] Table 1 Chemical composition (wt.%) and glass properties of the examples

[0061]

[0062]

[0063] The following are the raw materials used in the examples and their requirements:

[0064] Quartz sand (purity greater than 99.9%, particle size less than 0.5um), boron oxide (purity greater than 99.9%, particle size less than 0.5um), lithium carbonate (analytical grade), sodium carbonate (analytical grade), gadolinium oxide (purity greater than 99%, particle size less than 2.5um), yttrium oxide (analytical grade), germanium oxide (analytical grade), niobium oxide (analytical grade), zinc oxide (analytical grade), cerium oxide (analytical grade), tungsten oxide (analytical grade), and indium oxide (analytical grade).

[0065] Example 1

[0066] According to the glass composition of Example 1 in Table 1, raw materials are selected so that the ingredients meet the glass chemical composition of Table 1, and the Fe content in the glass raw materials is strictly controlled. The raw materials are mixed uniformly to obtain a batch material, and then the batch material is added to a platinum crucible at 1500°C and melted at high temperature for 6 hours. After the batch material is completely formed into a glass melt, the glass melt is stirred using a platinum stirrer at a stirring speed of 30 rpm for 3 hours. At the same time, oxygen is introduced into the glass melt using a platinum pipe at a ventilation flow rate of 0.3 L / min for 3 hours, so that the glass melt is clarified and homogenized in an oxygen-rich state. The glass melt is then cooled to 1300°C and poured into a heat-resistant steel mold preheated to 550°C by leaking material forming to solidify and form the glass. After it forms solid glass, the formed glass is placed in an annealing furnace at 670°C for 8 hours, and then the annealing furnace is turned off and cooled to room temperature to obtain neutron radiation-proof glass. Its test performance is shown in Table 1.

[0067] Example 2

[0068] According to the glass composition of Example 2 in Table 1, raw materials are selected so that the ingredients meet the glass chemical composition of Table 1, and the Fe content in the glass raw materials is strictly controlled. The raw materials are mixed uniformly to obtain a batch material, and then the batch material is added to a platinum crucible at 1400°C and melted at high temperature for 8 hours. After the batch material is completely formed into a glass melt, the glass melt is stirred using a platinum stirrer at a stirring speed of 40 rpm for 2 hours. At the same time, oxygen is introduced into the glass melt using a platinum pipe at a ventilation flow rate of 0.4 L / min for 2 hours, so that the glass melt is clarified and homogenized in an oxygen-rich state. The glass melt is then cooled to 1250°C and poured into a heat-resistant steel mold preheated to 500°C using a leaking forming method to solidify and form the cooled glass melt. After it forms solid glass, the formed glass is annealed in an annealing furnace at 650°C for 10 hours, and then the annealing furnace is turned off and cooled to room temperature to obtain neutron radiation-proof glass. Its test performance is shown in Table 1.

[0069] Example 3

[0070] According to the glass composition of Example 3 in Table 1, raw materials are selected so that the ingredients meet the glass chemical composition of Table 1, and the Fe content in the glass raw materials is strictly controlled. The raw materials are mixed uniformly to obtain a batch material, and then the batch material is added to a platinum crucible at 1450°C and melted at high temperature for 7 hours. After the batch material is completely formed into a glass melt, the glass melt is stirred using a platinum stirrer at a stirring speed of 45 rpm for 4 hours. At the same time, oxygen is introduced into the glass melt using a platinum pipe at a ventilation flow rate of 0.5 L / min for 4 hours, so that the glass melt is clarified and homogenized in an oxygen-rich state. The glass melt is then cooled to 1350°C and poured into a heat-resistant steel mold preheated to 600°C using a leaking forming method to solidify and form the cooled glass melt. After it forms solid glass, the formed glass is annealed in an annealing furnace at 710°C for 10 hours, and then the annealing furnace is turned off and cooled to room temperature to obtain neutron radiation-proof glass. Its test performance is shown in Table 1.

[0071] Example 4

[0072] The raw materials were selected according to the glass composition of Example 4 in Table 1, and the Fe content in the glass raw materials was strictly controlled so that the ingredients met the glass chemical composition of Table 1. The same melting process and test conditions as in Example 1 were used. The basic properties of the samples are shown in Table 1.

[0073] Example 5

[0074] The raw materials were selected according to the glass composition of Example 5 in Table 1, and the Fe content in the glass raw materials was strictly controlled so that the ingredients met the glass chemical composition of Table 1. The same melting process system and test conditions as in Example 1 were used. The basic properties of the samples are shown in Table 1.

[0075] The data obtained from the examples show that the neutron radiation shielding glass of the present invention does not contain any of the metal oxides or heavy metal oxides harmful to the environment, such as As2O3, Sb2O5, BaO, PbO, Tl2O, CdO, BeO, V2O5, etc., and is environmentally friendly. In addition, the neutron radiation shielding glass has a transmittance of greater than 80% at 550nm and a Knoop hardness of greater than 600 (×10 7 MPa); when the neutron dose rate is reduced to 50%, the thickness of the glass of the present invention is less than 30 mm, which can effectively protect against fast neutrons; by rationally configuring the components and their contents, the neutron radiation-proof glass obtained by the present invention has good radiation protection, glass forming properties, and chemical stability, and the optical uniformity of the neutron radiation-proof glass can reach 5×10 -6 The components provided by the present invention are easy to prepare large-sized and highly uniform neutron radiation-proof glass.

[0076] The present invention also provides an application of the above-mentioned neutron radiation-proof glass or the neutron radiation-proof glass prepared by the above-mentioned preparation method in neutron radiation protection and observation windows in nuclear reactor devices, aerospace, radiomedical examination, national defense and military, cosmic ray detection, environmental radiation detection, material detection, etc.

[0077] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art may make any modifications, equivalent substitutions, or improvements to the present invention within the spirit and scope of protection of the present invention, and such modifications or equivalent substitutions are deemed to fall within the scope of protection of the present invention.

Claims

1. A neutron radiation-proof glass, characterized in that: Prepared from the following oxides in wt.%:

2. The neutron radiation shielding glass according to claim 1, characterized in that: Prepared from the following oxides in wt.%:

3. The neutron radiation shielding glass according to any one of claims 1 to 2, characterized in that: The neutron radiation-proof glass is used in neutron ray protection of nuclear reactor devices.

4. The neutron radiation shielding glass according to any one of claims 1 to 2, characterized in that: The neutron radiation-proof glass is used in aerospace, radiomedical examination, and material testing for neutron ray protection.

5. The neutron radiation shielding glass according to any one of claims 1 to 2, characterized in that: The neutron radiation-proof glass is used in neutron ray protection for cosmic ray detection.

6. The neutron radiation shielding glass according to any one of claims 1 to 2, characterized in that: The neutron radiation-proof glass is used in neutron ray protection for environmental radiation detection.

7. The method for preparing neutron radiation shielding glass according to any one of claims 1 to 2, characterized in that: The following steps are involved: Relevant raw materials are weighed according to glass components, mixed evenly and placed in a platinum crucible, and then melted, stirred, formed and annealed at high temperature to obtain the neutron radiation-proof glass.

8. The method for preparing neutron radiation shielding glass according to claim 7, characterized in that: The glass melting process is to place the raw materials after uniform mixing at 1400-1500° C. and melt them for 6-8 hours to form a glass melt.

9. The method for preparing neutron radiation shielding glass according to any one of claims 7 to 8, characterized in that: The stirring is a process of stirring the glass melt into a molten glass body with a platinum stirrer until a clear and homogenized glass liquid is formed. The stirring speed is 30-45 revolutions per minute and the stirring time is 2-4 hours.

10. The method for preparing neutron radiation shielding glass according to any one of claims 7 to 9, characterized in that: During the entire stirring process, oxygen is introduced into the glass melt at a flow rate of 0.3-0.5 L / min to ensure the formation of an oxygen-rich glass melt stirring and homogenization process.

11. The method for preparing neutron radiation shielding glass according to any one of claims 7 to 10, characterized in that: The forming process is to cool the glass melt to 1250-1350°C and then pour it into a heat-resistant steel mold preheated to 500-600°C for forming.

12. The method for preparing neutron radiation shielding glass according to any one of claims 7 to 11, characterized in that: The annealing temperature is 650-710° C., the annealing time is 8-10 hours, and then the product is cooled to room temperature in the furnace.

Images