Strontium-90 source core for isotope power supply, source core module and preparation method of strontium-90 source core

Abstract

The invention provides a strontium-90 source core for an isotope power supply, the strontium-90 source core comprises a strontium source and first glass wrapping the strontium source, and the strontium source is selected from at least one of strontium oxide and strontium fluoride. The strontium-90 source core provided by the invention has relatively high strontium content per unit volume, the water leaching rate of a strontium source can be reduced, and the safety of the source core is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of isotope energy, and in particular to a strontium-90 source core, a source core module and a preparation method of the strontium-90 source core for an isotope power supply. Background Art

[0002] Radioactive isotope batteries, also known as isotope batteries, have the advantages of long service life, good adaptability to various harsh environmental conditions, compact structure and small size, high energy density, high reliability, and no need for frequent maintenance. Therefore, they are widely used in space exploration (such as artificial satellites, space probes), site setting in extreme land conditions (such as polar and desert weather stations), and sea navigation (such as lighthouses and navigation buoys).

[0003] Strontium-90 is a fission product widely found in high-level radioactive waste. It is cheap (the price of strontium-90 extracted from reprocessing in the United States is ~US$20 / g), has high decay energy (β decay), and a long half-life (28.6 years). It is a good isotope battery fuel.

[0004] The strontium-90 heat source is the energy source of the temperature difference strontium-90 isotope battery, and its core material is the strontium-90 source core. Considering that when used in a marine environment, for example, there is a risk that the source core protective cladding will rupture and cause the source core to contact the water body. In order to prevent strontium isotopes from dissolving into the water body, resulting in large-scale pollution of the environment by radioactive nuclides, strontium titanate with a high melting point and poor solubility in water is used as the source core material. However, the preparation process of the strontium titanate source core, including material preparation and ceramic firing, is complicated, a lot of radioactive waste liquid will be generated during the preparation process, and the preparation cost is high. Compared with the preparation process of strontium titanate, the preparation process of strontium fluoride source core is simple, and fluoride ions can be directly precipitated and separated by adding them to the strontium-containing solution. The use of melt casting to prepare the strontium fluoride source core can also avoid the process risks of unstable shrinkage and easy fragmentation during the manufacturing process of the source core, but strontium fluoride is slightly soluble in water, has poor safety, and is prone to radioactive pollution.

[0005] Therefore, it is necessary to develop a strontium-90 source core with low water leaching rate and high production efficiency. Summary of the invention

[0006] In view of this, the main purpose of the present invention is to provide a strontium-90 source core and a source core module for an isotope power source and a method for preparing the strontium-90 source core. The strontium-90 source core of the present invention has low water solubility, higher safety and simple preparation process.

[0007] To this end, the present invention provides a strontium-90 source core for an isotope power supply, wherein the strontium-90 source core comprises a strontium source and a first glass encapsulating the strontium source, wherein the strontium source is selected from at least one of strontium oxide and strontium fluoride.

[0008] In some embodiments, the strontium source is uniformly dispersed in the first glass in the form of powder; or, the strontium source is completely encapsulated by the first glass in the form of a block.

[0009] In some embodiments, the first glass is sintered from at least one group selected from the following raw material compositions:

[0010] (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2;

[0011] (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5;

[0012] (3) SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO. The present invention also provides a source core module for an isotope power supply, comprising at least one strontium-90 source core as described above, and a second glass completely encapsulating the at least one strontium-90 source core.

[0013] In some embodiments, the at least one strontium-90 source core is arranged in a stack.

[0014] In some embodiments, the second glass is sintered from at least one group selected from the following raw material compositions:

[0015] (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2;

[0016] (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5;

[0017] (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

[0018] The present invention also provides a method for preparing a strontium-90 source core for an isotope power source, comprising the following steps:

[0019] The first glass raw material composition and the strontium source are sintered at 800° C.-1200° C., and a strontium-90 source core is obtained after cooling, wherein the strontium-90 source core comprises the strontium source and a first glass encapsulating the strontium source; the strontium source is selected from at least one of strontium oxide and strontium fluoride.

[0020] In some embodiments, the first glass raw material composition is mixed with a strontium source and then pressed into a green body, the green body is sintered at 800° C.-1200° C., and cooled to obtain a strontium-90 source core.

[0021] In some embodiments, a strontium source in bulk form is sintered with a molten first glass raw material composition at 800° C. to 1200° C., and a strontium-90 source core is obtained after cooling.

[0022] In some embodiments, the first glass raw material composition is selected from one or more of the following compositions:

[0023] (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2;

[0024] (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5;

[0025] (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

[0026] The strontium-90 source core provided by the present invention has a higher strontium content per unit volume, which can improve the energy density of the isotope battery. Since strontium oxide and strontium fluoride are substances that are slightly soluble in water, the strontium source can be completely wrapped by glass, which can effectively isolate the strontium source and prevent leakage of the strontium source. In addition, when the strontium source is wrapped by glass, for example, when used in a water environment, the risk of structural disintegration of the strontium source due to contact with water can be reduced, and the water leaching rate of the strontium source in the source core can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of a strontium-90 source core in one embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of the structure of a strontium-90 source core in another embodiment of the present invention;

[0029] Figure 3 It is a structural schematic diagram of a source core module according to one embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of a process for preparing a source core according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0032] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In the event of a conflict, the present specification takes precedence.

[0033] It should be noted that, in the embodiments of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a method or device including a series of elements includes not only the elements explicitly stated, but also other elements not explicitly listed, or also includes elements inherent to the implementation of the method or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other related elements in the method or device including the element.

[0034] The chemical forms of strontium salts with high melting points and stable physical properties include: strontium titanate, strontium fluoride, and strontium oxide. The difficulty of converting strontium ions into the above three strontium salts is from high to low: strontium titanate, strontium fluoride, and strontium oxide. The physical properties of commonly used strontium salts and the materials involved in their preparation processes are shown in Table 1.

[0035] Table 1 Physical properties of materials involved in the preparation process of strontium salts

[0036] nature Strontium Titanate Strontium fluoride Strontium oxide Strontium carbonate Titanium Dioxide Melting point 2060℃ 1473℃ 2430℃ Decomposition at 1340℃ 1840℃ Water Solubility Poorly soluble Slightly soluble Poorly soluble Slightly soluble Poorly soluble

[0037] The preparation of strontium titanate generally requires combining strontium in ionic form with titanium dioxide through a precipitation reaction. After filtering out, the strontium-containing precipitate reacts with titanium dioxide through a high-temperature reaction to obtain strontium titanate. The powder particles are homogenized by ball milling, then pressed into a green body by cold pressing or hot pressing, and finally ceramicized by sintering. The preparation process for forming a strontium titanate ceramic source core is complex and costly.

[0038] Strontium fluoride can be prepared by adding fluoride ions to a strontium-containing solution, and then filtering and precipitating to obtain strontium fluoride material. The strontium fluoride material is melted at high temperature and poured into a high-temperature resistant container to form a strontium-90 source core. Strontium oxide can be obtained by concentrating a strontium-containing solution to obtain strontium nitrate crystals, and strontium oxide can be obtained by slowly heating and decomposing or microwave digestion. Alternatively, a carbonate precipitant is added to a strontium-containing solution, strontium carbonate is obtained by filtering, and strontium oxide is obtained after high-temperature decomposition. However, the strontium-containing solution used to prepare strontium oxide or strontium fluoride is generally a strontium-containing solution extracted from the spent fuel reprocessing process, and usually contains a large amount of radioactive impurities. These radioactive impurities may be present in the prepared strontium fluoride or strontium oxide material, affecting the subsequent sintering process, and even impurities with a large content may affect the sintering kinetics of the strontium salt material, resulting in the strontium salt being unable to be sintered or the sintered product being of poor quality. Removing these radioactive impurities usually requires complex processes and high costs, and will produce more radioactive waste. In addition, strontium oxide or strontium fluoride is a substance that is slightly soluble in water. When used in a marine environment, for example, there may be a risk of leakage of radioactive substances due to contact with water and disintegration of the source core when it comes into contact with water.

[0039] In view of this, the present invention provides a strontium-90 source core for an isotope power supply, the strontium-90 source core comprising a strontium source and a first glass encapsulating the strontium source, wherein the strontium source is selected from at least one of strontium oxide and strontium fluoride.

[0040] Table 2 below shows some property parameters of strontium oxide, strontium fluoride and strontium titanate. As can be seen from Table 2, the strontium content per unit volume of strontium oxide and strontium fluoride is higher than that of strontium titanate, wherein, compared with strontium titanate, the strontium content per unit volume of strontium oxide and strontium fluoride is increased by 63% and 21%, respectively. The present invention uses strontium oxide and / or strontium fluoride as a strontium source, and the preparation process of strontium oxide and strontium fluoride is simple, and compared with strontium titanate, it has a higher strontium content per unit volume, thereby improving the energy density of the isotope battery. Since strontium oxide and strontium fluoride are substances that are slightly soluble in water, the strontium source can be completely encapsulated by glass, which can effectively isolate the strontium source and prevent leakage of the strontium source. In addition, wrapping the strontium source with glass can reduce the risk of structural collapse of the strontium source due to contact with water when used in a water environment, and reduce the water leaching rate of the strontium source in the source core.

[0041] Table 2 Properties of strontium oxide, strontium fluoride and strontium titanate

[0042]

[0043]

[0044] The embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. The embodiments and drawings described below are only for exemplary purposes and should not be construed as limiting the scope of the present invention.

[0045] In some embodiments, the strontium source is uniformly dispersed in the first glass in the form of a powder.

[0046] Figure 1 FIG. 2 shows a schematic diagram of the structure of a strontium-90 source core in one embodiment of the present invention. Figure 1 As shown, the strontium source is evenly dispersed in the first glass in the form of powder and is wrapped by the first glass, thereby isolating the strontium source through the first glass and helping to reduce the water leaching rate of the strontium source in the source core. In addition, the strontium source is evenly dispersed in the first glass, and when the source core self-heats and causes a temperature gradient in the source core as a whole, the source core is less likely to break, which is more conducive to assembly; in unexpected situations, such as when the source core is exposed to water, the strontium source is evenly dispersed in the first glass, which helps to prevent the strontium source from structurally disintegrating after contacting water, thereby improving the safety of the strontium-90 source core.

[0047] In some embodiments, the strontium source is completely encapsulated by the first glass in the form of a bulk body.

[0048] Figure 2 FIG. 2 shows a schematic diagram of the structure of a strontium-90 source core in another embodiment of the present invention. Figure 2 As shown, the strontium source powder forms a block, and the block is entirely wrapped by the first glass, thereby wrapping the strontium source powder as a whole, further reducing the content of radioactive strontium-90 on the surface of the source core that can contact the outside world, which is beneficial to reducing the water leaching rate of the strontium source in the source core, reducing the leakage of radioactive substances, and can reduce the risk of structural collapse of the strontium source after contacting water, thereby improving the safety performance of the source core.

[0049] In some embodiments, the first glass is sintered from at least one group selected from the following raw material compositions:

[0050] (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2;

[0051] (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5;

[0052] (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

[0053] The first glass obtained by sintering the raw material composition has good radiation resistance and high temperature resistance above 800°C, and can be used in isotope batteries. In addition, the high-temperature surface properties of the glass formed by the raw material composition should be consistent with the surface properties of strontium oxide or strontium fluoride, that is, at high temperatures, the raw material composition spreads well on the surface of strontium oxide or strontium fluoride, and the first glass formed thereby is closely combined with the surface of strontium oxide or strontium fluoride, thereby improving the encapsulation of the strontium source.

[0054] In some embodiments, the mass ratio of the strontium source to the first glass is 10:0.5 to 1. By making the mass ratio of the strontium source to the first glass within the above range, the strontium content per unit volume / weight in the source core can be increased, thereby increasing the power of the isotope battery.

[0055] In some embodiments, the raw material composition comprises SiO2, B2O3, Al2O3, CaO, Na2O, TiO2. In some embodiments, based on the total weight of the raw material composition, the raw material composition comprises 50-60% SiO2, 10%-20% B2O3, 1%-5% Al2O3, 8%-15% CaO, 3%-9% Na2O and 0.5%-5% TiO2.

[0056] The present invention also provides a source core module for an isotope power source, comprising at least one strontium-90 source core and a second glass completely encapsulating the at least one strontium-90 source core.

[0057] By completely wrapping at least one source core with a second glass, on the one hand, the risk of leakage of radioactive materials can be further reduced, and the structural stability of the source core module can be improved, thereby improving the safety of the isotope battery. On the other hand, it is possible to design source core modules including different numbers of source cores and different source core forms according to the application scenarios of the isotope battery. The present invention does not specifically limit the number of strontium-90 source cores in the source core module, and those skilled in the art can select source core modules including different numbers of source cores according to the power required by the isotope battery. Exemplarily, the source core module may include 1, 2, 3, 4, 5, ..., 10 source cores or more.

[0058] In some embodiments, the at least one strontium-90 source core is arranged in a stack.

[0059] In some embodiments, the mass proportion of the strontium source is greater than or equal to 85% of the total weight of the source core module; preferably greater than or equal to 90%; more preferably 90%-96%. This is conducive to increasing the strontium content of the source core module per unit volume or unit weight, thereby increasing the power of the isotope battery.

[0060] Figure 3FIG. 2 is a schematic diagram showing the structure of a source core module according to an embodiment of the present invention. Figure 3 Said, in the source core module, at least one strontium-90 source core is stacked.

[0061] In some embodiments, the second glass is sintered from at least one group selected from the following raw material compositions:

[0062] (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2;

[0063] (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5;

[0064] (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

[0065] The second glass sintered from the raw material composition has good radiation resistance and high temperature resistance, and is suitable for isotope batteries. In addition, the raw material composition has good processing performance and low cost, which is conducive to simplifying the production process and cost of the source core module.

[0066] In the present invention, the first glass and the second glass may be the same or different. A person skilled in the art may select the raw material composition of the first glass and the second glass as required.

[0067] The present invention also provides a method for preparing a strontium-90 source core for an isotope power source, comprising the following steps: sintering a first glass raw material composition and a strontium source at 800°C-1200°C, and obtaining a strontium-90 source core after cooling, wherein the strontium-90 source core comprises the strontium source and a first glass completely comprising the strontium source; the strontium source is selected from at least one of strontium oxide and strontium fluoride. During the sintering process at 800°C-1200°C, the first glass raw material composition melts, but the strontium source (such as strontium oxide or strontium fluoride) has a relatively high melting point and remains in a solid state at this temperature, so that the glass raw material composition can wrap the strontium source after melting, and forms glass that completely wraps the strontium source after cooling.

[0068] Compared with the traditional process of sintering the strontium source into a ceramic process, the sintering temperature of the method of the present invention is lower, which is conducive to saving energy consumption. In addition, since the strontium source mainly comes from the strontium-containing solution produced in the spent fuel reprocessing process, which usually contains more radioactive impurities, and the impurity components in different batches of strontium-containing solutions are different, it is difficult to control its quality. These radioactive impurities will affect the sintering dynamics of the strontium source in the traditional ceramic process, resulting in poor structural stability of the strontium source sintered product, and may even be unable to sinter into shape. Compared with the traditional ceramic process, the method of the present invention is used to sinter and form glass at a lower temperature, and the strontium source is wrapped by the process of sintering glass. Thus, the sintering dynamics of the source core preparation process is transformed into a glass raw material composition dominated by the sintering temperature, which is not affected by the sintering temperature of the strontium source or the radioactive impurities in the strontium source, and the production efficiency and quality of the production process are improved. Exemplarily, the sintering temperature can be 800°C, 900°C, 1000°C, 1100°C, 1200°C, or a value between the ranges composed of any two of them. In the present invention, sintering can be performed using conventional methods and equipment in the art, and the present invention does not make any specific limitation thereto.

[0069] In some embodiments, the first glass raw material composition is mixed with the strontium source and then pressed into a green body. The first glass raw material composition is mixed with the strontium source and then pressed into a green body so that the strontium source can be uniformly dispersed in the first glass, and after sintering, the first glass completely wraps the strontium source, thereby reducing the leakage of radioactive substances and the water leaching rate of the strontium source.

[0070] In some embodiments, the mixing is performed by ball milling, so that the strontium source is uniformly dispersed in the first glass raw material composition by ball milling.

[0071] In some embodiments, the ball milling time is 5-30 min.

[0072] In some embodiments, the pressing into a green body is performed at 100-300 MPa.

[0073] In other embodiments, a strontium source in block form is sintered with a molten first glass raw material composition at 800°C-1200°C, and a strontium-90 source core is obtained after cooling. In some embodiments, the strontium source is pressed into a block and placed in a molten first glass raw material composition, and after sintering and cooling, a source core of the first glass-wrapped strontium source block is formed. In some embodiments, the strontium source is a block formed after sintering strontium oxide or strontium fluoride. In some embodiments, the sintering is carried out in air, protective gas or vacuum environment. In some embodiments, the protective gas is nitrogen.

[0074] In some embodiments, the sintering time is 3-6 hours.

[0075] Figure 4 FIG. 1 is a schematic diagram showing a process of preparing a source core according to an embodiment of the present invention. Figure 4 As shown, a molten first glass raw material composition is placed in a high temperature resistant metal barrel, a pressed block strontium source or a sintered strontium source block is placed in the molten first glass raw material composition, sintered at 800-1200°C, and cooled to form a strontium-90 source core, wherein the first glass completely encapsulates the strontium source. It is understandable that the source core module provided by the present invention can also be used as follows Figure 4 The process shown is to place the source core into the molten second glass raw material composition, sinter and cool to obtain the source core module, wherein the second glass wraps at least one source core.

[0076] In some embodiments, the first glass raw material composition and / or the second glass raw material composition is selected from one or more of the following compositions:

[0077] (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2;

[0078] (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5;

[0079] (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

[0080] In the present invention, the first glass raw material composition and the second glass raw material composition may be the same or different. The glass prepared by using the glass raw material composition has good radiation resistance and sealing performance, and can reduce the water leaching rate of the strontium source.

[0081] Example

[0082] (1) 10 g of strontium fluoride was weighed and 0.5 g of a first glass raw material composition was added, wherein the composition of the first glass raw material composition was as follows:

[0083]

[0084] (2) The mixed materials are loaded into a high-energy vibration ball mill and mixed by high-frequency vibration for 20 minutes;

[0085] (3) taking out the material, filling it into an alloy mold, cold pressing it at 300 MPa, demolding it, and forming a green billet;

[0086] (4) The green body is transferred to a high temperature furnace and calcined in a vacuum environment at a temperature of 1000° C. for 3 hours;

[0087] (5) Obtain a first glass-encased strontium source core.

[0088] After the source cores were washed, three identical source cores were transferred to 40 ml of deionized water and soaked according to the method provided in GB / T 7023-2011. The room temperature was maintained at about 25°C. After 24 hours, samples were taken to test the strontium content in the solution. The average strontium content in the solution tested for the three groups of source cores was <1 μg / ml, indicating that the source cores of the present invention have a reduced water leaching rate.

[0089] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A strontium-90 source core for an isotope power source, characterized in that: The strontium-90 source core comprises a strontium source and a first glass encapsulating the strontium source, wherein the strontium source is selected from at least one of strontium oxide and strontium fluoride.

2. The strontium-90 source core according to claim 1, characterized in that: The strontium source is uniformly dispersed in the first glass in the form of powder; or The strontium source is completely enclosed by the first glass in the form of a block.

3. The strontium-90 source core according to claim 1 or 2, characterized in that: The first glass is sintered from at least one group selected from the following raw material compositions: (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2; (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5; (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

4. A source core module for an isotope power source, characterized in that: The method comprises at least one strontium-90 source core according to any one of claims 1 to 3, and a second glass completely encapsulating the at least one strontium-90 source core.

5. The source core module according to claim 4, characterized in that: The at least one strontium-90 source core is arranged in a stacked manner.

6. The source core module according to claim 4 or 5, characterized in that: The second glass is sintered from at least one group selected from the following raw material compositions: (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2; (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5; (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

7. A method for preparing a strontium-90 source core for an isotope power source, characterized in that: The following steps are involved: The first glass raw material composition and the strontium source are sintered at 800° C.-1200° C., and a strontium-90 source core is obtained after cooling, wherein the strontium-90 source core comprises the strontium source and a first glass encapsulating the strontium source; the strontium source is selected from at least one of strontium oxide and strontium fluoride.

8. The preparation method according to claim 7, characterized in that: The first glass raw material composition is mixed with a strontium source and pressed into a green body, the green body is sintered at 800° C.-1200° C., and a strontium-90 source core is obtained after cooling.

9. The preparation method according to claim 7, characterized in that: The strontium source in bulk form is sintered with the molten first glass raw material composition at 800° C.-1200° C., and a strontium-90 source core is obtained after cooling.

10. The preparation method according to claim 1 or 2, characterized in that: The first glass raw material composition is selected from one or more of the following compositions: (1)SiO2, B2O3, Al2O3, CaO, Na2O, TiO2; (2) SiO2, H3BO3, CaCO3, Na2CO3, LiCO3, BaCO3, MgO, Al2O3, V2O5, Sb2O5; (3)SiO2, B2O3, Na2O, Al2O3, Li2O, CaO, MgO, BaO.

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