Method for testing iron reduction index change in glass before and after irradiation

Abstract

The invention belongs to the technical field of glass testing, and discloses a method for testing iron reduction index change in glass before and after irradiation, and the method comprises the following steps: firstly, measuring the absorption spectrum of the glass before and after irradiation in the wave band range of 200-1300 nm, and then directly recording the absorbance of Fe < 2 + > at the characteristic wave bands of 1055 nm and 520 nm; the absorbance at the position of 520 nm in the absorption spectrum serves as the baseline absorbance, the relation between the iron reduction index in the glass before and after irradiation and the product of the extinction coefficient and the total iron concentration is obtained, the relation is the iron reduction index, and KFe < 2 + > is the product of the extinction coefficient of Fe < 2 + > and the total iron concentration, cm <-1 >; then calculating the change rate of the iron reduction index in the glass before and after irradiation; according to the method, the iron reduction index of the glass and the change before and after irradiation can be quickly calculated.

Description

Technical Field

[0001] The invention belongs to the technical field of glass testing and relates to a method for testing the change of iron reduction index in glass before and after irradiation. Background Art

[0002] Irradiated glass is a glass material whose properties are changed after radiation treatment. It is widely used in aerospace components, nuclear waste solidification, radiation shielding and optical devices. Irradiation can cause the valence of some transition metal oxides in the glass to change, affecting the optical effect, structural stability and shielding effectiveness of the glass. Among them, iron is one of the main transition metals in glass, Fe 2+ and Fe 3+ The transformation is closely related to the performance of glass.

[0003] At present, the test of ferrous iron content mainly adopts chemical titration, Mössbauer spectroscopy and spectrophotometry, but these methods have obvious shortcomings: chemical titration destroys the sample and has low accuracy, Mössbauer spectroscopy equipment is expensive and complicated to operate, and the existing spectrophotometry method generally requires pretreatment of the sample to be tested, such as the phenanthroline method requires Fe 2+ It forms a stable orange-red complex with o-phenanthroline in a solution with a pH of 2 to 9. The ferrozine method requires Fe 2+ It forms a purple complex with ferrozine (3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine), and then measures the absorbance at the corresponding maximum absorption wavelength. Finally, the concentration is calculated based on the standard curve. However, these methods have long cycles, high costs, and are not non-destructive in situ detection.

[0004] Patent No. CN102004084B discloses a method for determining the content of ferrous ions and ferric ions in glass. The method uses spectrophotometry to test the continuous absorbance spectrum of the glass sample in the range of 1100 nm to 350 nm. 2+ and Fe 3+ The corresponding two regions 370~400 nm and 520~1100 nm were integrated to obtain the peak area, and then the Fe 2+ and Fe 3+ Although this method greatly improves detection efficiency, due to the complex composition and structure of glass, the absorption peak of 520-1100 nm will contain the absorption peaks of other elements, affecting the accuracy of the results. At the same time, peak integration requires manual operations such as baseline calibration and smoothing of the spectrum, which increases the introduction of uncertainties.

[0005] Therefore, it is of great significance to develop a fast, non-destructive and high-precision test method for the change of iron reduction index in glass before and after irradiation. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and to provide a method for testing the change of the iron reduction index in glass before and after irradiation.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A method for testing the change of iron reduction index in glass before and after irradiation, firstly, the absorption spectrum of the glass in the 200~1300 nm range before and after irradiation is measured by spectrophotometer, and then the Fe 2+ absorbance at a characteristic wavelength of 1055 nm in the absorption spectrum and absorbance at 520 nm in the absorption spectrum; wherein the glass comprises iron oxide;

[0009] The absorbance at 520 nm in the absorption spectrum was used as the baseline absorbance to obtain the iron reduction index and Fe 2+ The relationship between the extinction coefficient and the product of the total iron concentration is used to calculate the change rate of the iron reduction index in the glass before and after irradiation;

[0010] The components of glass include iron oxide, iron element in the form of Fe 3+ and / or Fe 2+ There are Fe in the glass after irradiation. 2+ and Fe 3+ The mutual conversion phenomenon, iron reduction index refers to the Fe 2+ The ratio of the iron concentration to the total iron (ΣFe) concentration;

[0011] Iron reduction index and Fe 2+ The relationship formula of the product of the extinction coefficient and the total iron concentration is: ;

[0012] in, is the iron reduction index, dimensionless; Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1 ; L is the glass thickness, cm; and Read through absorption spectrum; L is measured with a ruler, and the measurement accuracy must be high, reaching 0.01 mm or higher;

[0013] Iron reduction index and Fe 2+The relationship between the extinction coefficient and the total iron concentration is derived from the Beer's law. The Beer's law formula is: A = •c•L; where A is the absorbance, dimensionless, is the extinction coefficient, unit is L•mol -1 •cm -1 , c is the concentration of the absorbing substance, in mol / L, L is the glass thickness, in cm; considering the removal of baseline absorbance, Fe 2+ The concentration is calculated as follows: ; Fe 2+ The concentration of Fe 2+ The extinction coefficient of Fe 2+ The relationship formula between the extinction coefficient and the product of the total iron concentration needs to be divided by the total iron concentration on both sides to obtain the formula; the method of this application is used to calculate the change rate of the iron reduction index in the glass before and after irradiation, without calculating K Fe2+ You can get it;

[0014] The reason why the absorbance at 520 nm in the absorption spectrum is used as the baseline absorbance is as follows:

[0015] In the near-infrared band of 1300 nm to the ultraviolet band of 200 nm, each band has absorbance caused by interference from base sample absorption and external radiation. Base sample absorption refers to the nonspecific absorption caused by the glass matrix itself (such as SiO2 network) and inevitable trace impurities (such as OH-, trace residues of transition metals); external radiation includes non-chemical factors such as ambient light scattering, surface contamination, and test instrument drift. In the existing technology, the absorption spectrum of the blank sample is usually used as the baseline absorbance of the test sample to remove the interference caused by base sample absorption and external radiation. However, different operating techniques and external factors will lead to different baseline absorbances, making the obtained Fe 2+ The content of Fe 2+ Glasses with different contents almost all show the lowest absorbance at 520 nm, which shows that Fe 2+ The absorbance at 520 nm is very low and can be basically ignored; therefore, we can conclude that the absorbance at 520 nm = absorbance caused by interference + very low content of Fe 2+ Absorbance; Since this application directly records Fe 2+The absorbance at the characteristic band of 1055 nm in the absorption spectrum was not baseline corrected (although the absorbance of interference at different bands was different, it could be ignored). Then, the evolution formula of Beer's law (iron reduction index and Fe 2+ The iron reduction index can be obtained by multiplying the extinction coefficient of the glass by the total iron concentration. In summary, the method of the present application does not require testing a blank sample, which is simpler and overcomes the common belief in the art that a blank sample must be tested and a baseline correction must be performed before the accurate determination of the Fe content in the glass can be obtained. 2+ The technical bias of concentration is reduced. Since the same absorption spectrum is used to remove interference instead of the absorption spectrum of the blank sample, the error after removing the interference is smaller.

[0016] The calculation method is: take the glass with an iron reduction index of 1 as the standard sample, and then =1 is substituted into the iron reduction index and Fe 2+ The product of the extinction coefficient and the total iron concentration is used to calculate K Fe2+ Among them, the content of each element in the raw materials of the glass with an iron reduction index of 1 is exactly the same as that of the test sample; the glass with an iron reduction index of 1 means that the glass contains only Fe 2+ , no Fe 3+ , at this time the iron reduction index in the glass is 1;

[0017] When calculated Later, Substitute the iron reduction index and Fe 2+ The relationship formula of the product of the extinction coefficient and the total iron concentration is obtained, thereby obtaining the calculation formula of the iron reduction index of the test sample, and then the specific value of the iron reduction index can be calculated;

[0018] Compared with the formula of Beer's law, the formula of this application can calculate K Fe2+ still There is no need to calculate the total iron concentration. The total iron concentration needs to be obtained by dividing the molar amount of total iron in the raw materials of the glass by the volume of the glass, and the unit is mol / L. The existing technology uses the formula of Beer's law to calculate , or by Convert to All of them require knowing the total iron concentration, and the calculation is cumbersome.

[0019] As the preferred technical solution:

[0020] As described above, a test method for the change of the iron reduction index in glass before and after irradiation is provided. The preparation method of glass with an iron reduction index of 1 is as follows: placing the raw material of the glass in an atmosphere furnace filled with nitrogen or inert gas, heating it to the melting temperature of the glass (viscosity less than 10 Pa•s) and keeping it warm until the raw material of the glass is uniformly melted, then pouring it into a mold and annealing it in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining glass with an iron reduction index of 1; the preparation method of the glass with an iron reduction index of 1 is different from the preparation method of the test sample in that: during the preparation process of the glass with an iron reduction index of 1, nitrogen or inert gas needs to be introduced into the atmosphere furnace to ensure that there is as little oxygen as possible in the furnace; in addition, a small amount of carbon powder can be added when placing the raw material of the glass to fully react with the residual oxygen in the furnace, but the carbon powder should not be added too much, otherwise it will cause Fe 2+ Reduction generates Fe element and precipitates; this application selects a certain temperature when the viscosity is lower than 10 Pa•s as the melting temperature of the glass, and the reference is (Glass length: Workability and meltability of glass as a function of glass melt fragility) [J]. Journal of Non-Crystalline Solids, 597 (2022)121931.).

[0021] In the above-mentioned test method for the change of the iron reduction index in glass before and after irradiation, the measurement range of the spectrophotometer includes a wavelength range of 200 to 1300 nm, that is, the near-infrared band is not lower than 1300 nm and the ultraviolet band is not higher than 200 nm.

[0022] In the above-mentioned method for testing the change of the iron reduction index in glass before and after irradiation, before measuring the glass before and after irradiation with a spectrophotometer, both sides of the glass need to be polished to a surface roughness Ra ≤ 0.1 μm and no impurities remain on the surface.

[0023] As described above, a test method for the change of iron reduction index in glass before and after irradiation is provided, wherein the raw materials of the glass are composed of 72 wt % SiO2, 14 wt % Na2O, 13 wt % CaO and 1 wt % FeO.

[0024] As described above, a test method for the change of iron reduction index in glass before and after irradiation, when the raw materials of the glass are composed of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO, =7.7057 cm -1 .

[0025] Beneficial effects:

[0026] The present invention provides a method for testing the change in iron reduction index in glass before and after irradiation, which does not require testing a blank sample. The method is simpler and overcomes the common belief in the art that a blank sample must be tested first and a baseline correction must be performed to accurately obtain the Fe reduction index in the glass. 2+ The technical bias of concentration is eliminated, and because the same absorption spectrum is used to remove interference instead of the absorption spectrum of the blank sample, the error after removing the interference is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Absorption spectra of glass I to glass IV prepared in the present invention when the thickness is 1 cm;

[0028] Figure 2 When the thickness of glass I to glass IV prepared by the present invention is 1 cm, the Fe content in the glass is 2+ Schematic diagram of the linear relationship between the absorbance at the characteristic band of 1055 nm in the absorption spectrum and the amount of FeO added;

[0029] Figure 3 When the thickness of glass I to glass IV prepared by the present invention is 1 cm, the Fe content in the glass is 2+ Schematic diagram of the linear relationship between the absorbance at 1055 nm in the characteristic band of the absorption spectrum minus the absorbance at 520 nm in the absorption spectrum and the amount of FeO added; in the figure, A 1055 -A 520 Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is subtracted from the absorbance at 520 nm in the absorption spectrum;

[0030] Figure 4 1 is the absorption spectrum of the glass prepared in Example 1 before and after irradiation;

[0031] Figure 5 This is the absorption spectrum of the glass prepared in Example 2 before and after irradiation. DETAILED DESCRIPTION

[0032] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0033] In order to verify the absorbance of A 1055 -A 520 Accuracy is better than A 1055 , now we give an example to prove that the specific process is as follows:

[0034] First, prepare four glasses with different iron reduction indexes of 1:

[0035] Glass I: The raw glass was placed in a nitrogen atmosphere furnace, heated to 1450°C (high-temperature viscosity: 8 Pa·s), and maintained at this temperature until the raw glass melted uniformly. The glass was then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated. The glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, leaving no impurities on the surface. This yielded Glass I with a thickness of 0.303 cm and an iron reduction index of 1. The raw glass was composed of 72.98 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 0.02 wt% FeO.

[0036] Glass II: The raw glass was placed in a nitrogen atmosphere furnace, heated to 1450°C (high-temperature viscosity of 8 Pa·s), and maintained at this temperature until the raw glass was uniformly melted. The glass was then poured into a mold and annealed in an annealing furnace to eliminate internal stress. The glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, leaving no impurities on the surface. This yielded Glass II with a thickness of 0.400 cm and an iron reduction index of 1. The raw glass consisted of 72.92 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 0.08 wt% FeO.

[0037] Glass III: The raw glass was placed in a nitrogen atmosphere furnace, heated to 1450°C (high-temperature viscosity of 8 Pa·s), and maintained at this temperature until the raw glass melted uniformly. The glass was then poured into a mold and annealed in an annealing furnace to eliminate internal stress. The glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, leaving no impurities on the surface. This yielded Glass III with a thickness of 0.699 cm and an iron reduction index of 1. The raw glass was composed of 72.87 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 0.13 wt% FeO.

[0038] Glass IV: The raw glass was placed in a nitrogen atmosphere furnace, heated to 1450°C (high-temperature viscosity of 8 Pa·s), and maintained at this temperature until the raw glass melted uniformly. The glass was then poured into a mold and annealed in an annealing furnace to eliminate internal stress. The glass was cut and polished on both sides to a surface roughness Ra of 0.1 μm, leaving no impurities on the surface. This yielded Glass IV with a thickness of 1.012 cm and an iron reduction index of 1. The raw glass consisted of 72.81 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 0.19 wt% FeO.

[0039] Under the conditions of the same glass composition and thickness, from a theoretical point of view, without considering the influence of external interference, the FeO addition amount is the same as the Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is linear. According to Beer's law, thickness is proportional to absorbance. Since the thickness of glass I to glass IV is different, in order to facilitate research, it is necessary to remove the interference of thickness on absorbance. Therefore, the absorbance in the absorption spectrum of glass I to glass IV needs to be divided by the thickness of the glass, so as to obtain the following: Figure 1 The absorption spectra of Glass I to Glass IV are shown when the thickness is 1 cm;

[0040] Among them, Fe in 1cm thick glass I 2+ The absorbance A at the characteristic band of 1055 nm in the absorption spectrum is 0.1341, and the absorbance at 520 nm in the absorption spectrum is 0.0713;

[0041] Fe in 1cm thick glass II 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 0.4469, and the absorbance at 520 nm in the absorption spectrum is 0.0919;

[0042] Fe in 1cm thick glass III 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 0.6704, and the absorbance at 520 nm in the absorption spectrum is 0.0791;

[0043] Fe in 1cm thick glass IV 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 1.0854, and the absorbance at 520 nm in the absorption spectrum is 0.2224;

[0044] From the above, we can see that with the increase of FeO addition in the glass raw material formula, Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum also increases;

[0045] Then the FeO addition amount in the glass raw materials of glass I to glass IV and the Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum (A 1055 ) and perform fitting, the results are as follows Figure 2 As shown in the figure, the two are in a linear relationship (conforming to the linear equation y=ax+b), and the goodness of fit R 2 is 0.9570;

[0046] The FeO addition amount in the glass raw materials of Glass I to Glass IV and the Fe 2+ The absorbance at 1055 nm in the characteristic band of the absorption spectrum is subtracted from the absorbance at 520 nm in the absorption spectrum (A 1055 -A 520 ) is fitted, and the result is as follows Figure 3 As shown in the figure, the two are also linearly related, and the goodness of fit R 2 is 0.9839;

[0047] In summary, the absorbance at 520 nm in the absorption spectrum is used as the baseline absorbance, which can minimize the interference caused by the base sample absorption and external emission, making the goodness of fit R 2 Closer to linear fitting, it can effectively reduce the error caused by the test and improve the accuracy of the test.

[0048] Example 1

[0049] A method for testing the change in iron reduction index in glass before and after irradiation, comprising the following steps:

[0050] (1) Preparation of glass with an iron reduction index of 1 (used to simulate the preparation of glass in an oxygen-free environment);

[0051] The raw glass material was placed in a nitrogen atmosphere furnace, heated to 1450°C (high-temperature viscosity of 8 Pa·s), and maintained at this temperature until the raw glass material was uniformly melted. The glass was then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated, thereby obtaining a 0.404 cm thick glass with an iron reduction index of 1. The raw glass material consisted of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 1 wt% FeO.

[0052] (2) First, a glass with an iron reduction index of 1 is used as the test glass, and then both sides are polished to a surface roughness Ra of 0.1 μm. Then, the absorption spectrum of the test glass in the 200~1300 nm band before and after irradiation is measured by a spectrophotometer (e.g. Figure 4 Then record the Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 3.3024, and the absorbance at 520 nm in the absorption spectrum is 0.1893. The Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 3.2173, and the absorbance at 520 nm in the absorption spectrum is 0.2087. The irradiation type is electron irradiation, the intensity is 10 MeV, and the fluence is 5E14 / cm 2 ;

[0053] (3) Then, the absorbance at 520 nm in the absorption spectrum was used as the baseline absorbance to obtain the iron reduction index and Fe 2+ The relationship between the extinction coefficient and the product of the total iron concentration was calculated, and the change rate of the iron reduction index in the glass before and after irradiation was reduced by 3.36%; among them, the iron reduction index is related to Fe 2+ The relationship between the extinction coefficient and the total iron concentration is: , where is the iron reduction index, dimensionless; Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1 ; L is the glass thickness, cm;

[0054] (4) The glass with an iron reduction index of 1 obtained in step (1) is used as a standard sample, and then =1 is substituted into the iron reduction index and Fe 2+ The product of the extinction coefficient and the total iron concentration is used to calculate K Fe2+ =7.7057cm -1 ;

[0055] (5) The absorbance of the glass to be tested obtained in step (2) and the K obtained in step (4) are Fe2+ Substitute the iron reduction index and Fe 2+ From the relationship formula of the product of the extinction coefficient and the total iron concentration, it can be seen that the iron reduction index in the tested glass after irradiation is 0.9664.

[0056] Example 2

[0057] A method for testing the change in iron reduction index in glass before and after irradiation, comprising the following steps:

[0058] (1) Prepare the glass to be tested;

[0059] The glass raw material was placed in an atmosphere furnace under air atmosphere, heated to 1450°C (high temperature viscosity of 8 Pa·s), and kept warm until the glass raw material was uniformly melted. The glass raw material was then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated, thereby obtaining a glass to be tested with a thickness of 0.408 cm. The glass raw material was composed of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 1 wt% FeO.

[0060] (2) First, polish both sides of the glass to be tested in step (1) to a surface roughness Ra of 0.1 μm, so that no impurities remain on the surface. Then, use a spectrophotometer to measure the absorption spectrum of the glass to be tested in the 200-1300 nm band before and after irradiation (e.g. Figure 5 Then record the Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 0.5732, and the absorbance at 520 nm in the absorption spectrum is 0.1122. The Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 0.6291, and the absorbance at 520 nm in the absorption spectrum is 0.1051. The irradiation type is electron irradiation, the intensity is 10 MeV, and the fluence is 5E14 / cm 2 ;

[0061] (3) Taking the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, the iron reduction index and Fe 2+ The relationship between the extinction coefficient and the product of the total iron concentration was calculated, and the change rate of the iron reduction index in the glass before and after irradiation increased by 13.67%; Among them, the iron reduction index is related to Fe 2+ The relationship between the extinction coefficient and the total iron concentration is: , where is the iron reduction index, dimensionless; Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1 ; L is the glass thickness, cm;

[0062] (4) Preparation of glass with an iron reduction index of 1;

[0063] The raw glass material is placed in a nitrogen atmosphere furnace, heated to 1450°C (high-temperature viscosity of 8 Pa·s), and maintained at this temperature until the raw glass material is uniformly melted. The raw glass material is then poured into a mold and annealed in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining a 0.404 cm thick glass with an iron reduction index of 1. The raw glass material is composed of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO, and 1 wt% FeO.

[0064] (5) Polish both sides of the glass with an iron reduction index of 1 in step (4) to a surface roughness Ra of 0.1 μm, so that no impurities remain on the surface. Then, measure the absorption spectrum of the glass before and after irradiation in the 200-1300 nm band by a spectrophotometer, and record the Fe 2+ The absorbance at the characteristic wavelength of 1055 nm in the absorption spectrum is 3.3024, and the absorbance at 520 nm in the absorption spectrum is 0.1893. At the same time, the thickness of the glass to be tested was measured to be 0.404 cm using a high-precision thickness measuring tool.

[0065] The glass with an iron reduction index of 1 is used as a standard sample, and then =1 is substituted into the iron reduction index and Fe 2 + The product of the extinction coefficient and the total iron concentration is used to calculate K Fe2+ =7.7057 cm -1 ;

[0066] (6) Substitute the absorbance of the glass to be tested obtained in step (2) and the K obtained in step (5) Fe2+ Substitute the iron reduction index and Fe 2+ From the formula of the product of the extinction coefficient and the total iron concentration, it can be seen that the iron reduction index in the glass to be tested before irradiation is The iron reduction index in the glass to be tested after irradiation is 0.1466. It is 0.1667.

[0067] Example 3

[0068] A method for testing the change in iron reduction index in glass before and after irradiation, comprising the following steps:

[0069] (1) Preparation of glass with an iron reduction index of 1;

[0070] The glass raw materials are placed in a nitrogen atmosphere furnace, heated to 1550°C (high temperature viscosity is 9 Pa·s), and then maintained at this temperature until the glass raw materials are uniformly melted. The glass raw materials are then poured into a mold and annealed in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining a 1.030 cm thick glass with an iron reduction index of 1. The glass raw materials are composed of 63 wt% SiO2, 18 wt% Al2O3, 17 wt% MgO, 0.15 wt% FeO, 0.5 wt% B2O3, 0.35 wt% ZrO2, and 1.0 wt% TiO2.

[0071] (2) First, take the glass with an iron reduction index of 1 as the test glass, then polish both sides of it to a surface roughness Ra of 0.1 μm, so that there is no impurity residue on the surface, and then use a spectrophotometer to measure the absorption spectrum of the test glass in the 200~1300 nm band before and after irradiation, and then record the Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 2.4008, and the absorbance at 520 nm in the absorption spectrum is 0.1874. The Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 2.3686, and the absorbance at 520 nm in the absorption spectrum is 0.2628. The irradiation type is electron irradiation, the intensity is 1 MeV, and the fluence is 5E14 / cm 2 ;

[0072] (3) Then, the absorbance at 520 nm in the absorption spectrum was used as the baseline absorbance to obtain the iron reduction index and Fe 2+ The relationship between the extinction coefficient and the product of the total iron concentration was calculated, and the change rate of the iron reduction index in the glass before and after irradiation was reduced by 4.86%; among them, the iron reduction index is related to Fe 2+ The relationship between the extinction coefficient and the total iron concentration is: , where is the iron reduction index, dimensionless; Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1 ; L is the glass thickness, cm;

[0073] (4) The glass with an iron reduction index of 1 obtained in step (1) is used as a standard sample, and then =1 is substituted into the iron reduction index and Fe 2+ The product of the extinction coefficient and the total iron concentration is used to calculate K Fe2+ =2.1489cm -1 ;

[0074] (5) The absorbance of the glass to be tested obtained in step (2) and the K obtained in step (4) are Fe2+ Substitute the iron reduction index and Fe 2+ From the relationship formula of the product of the extinction coefficient and the total iron concentration, it can be seen that the iron reduction index in the tested glass after irradiation is 0.9514.

[0075] Example 4

[0076] A method for testing the change in iron reduction index in glass before and after irradiation, comprising the following steps:

[0077] (1) Prepare the glass to be tested;

[0078] The glass raw materials were placed in an atmosphere furnace under air atmosphere, heated to 1550°C (high temperature viscosity of 9 Pa·s), and kept warm until the glass raw materials were uniformly melted. The glass raw materials were then poured into a mold and annealed in an annealing furnace until the internal stress of the glass was eliminated, thereby obtaining a glass to be tested with a thickness of 0.997 cm. The glass raw materials consisted of 63wt% SiO2, 18wt% Al2O3, 17wt% MgO, 0.15wt% FeO, 0.5wt% B2O3, 0.35wt% ZrO2, and 1.0wt% TiO2.

[0079] (2) First, polish both sides of the glass to be tested in step (1) to a surface roughness Ra of 0.1 μm, and then measure the absorption spectrum of the glass to be tested in the 200-1300 nm band before and after irradiation by a spectrophotometer, and then record the Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 0.5499, and the absorbance at 520 nm in the absorption spectrum is 0.1059. The Fe 2+ The absorbance at the characteristic wavelength of 1055 nm in the absorption spectrum is 0.5752, and the absorbance at 520 nm in the absorption spectrum is 0.1093. The irradiation type is electron irradiation, the intensity is 1 MeV, and the fluence is 5E14 / cm 2 ;

[0080] (3) Taking the absorbance at 520 nm in the absorption spectrum as the baseline absorbance, the iron reduction index and Fe 2+ The relationship between the extinction coefficient and the product of the total iron concentration was calculated, and the change rate of the iron reduction index in the glass before and after irradiation increased by 4.93%; among them, the iron reduction index and Fe 2+ The relationship between the extinction coefficient and the total iron concentration is: , where is the iron reduction index, dimensionless; Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1; L is the glass thickness, cm;

[0081] (4) Preparation of glass with an iron reduction index of 1;

[0082] The glass raw materials are placed in a nitrogen atmosphere furnace, heated to 1550°C (high temperature viscosity is 9 Pa·s), and then maintained at this temperature until the glass raw materials are uniformly melted. The glass raw materials are then poured into a mold and annealed in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining glass with an iron reduction index of 1. The glass raw materials are composed of 63wt% SiO2, 18wt% Al2O3, 17wt% MgO, 0.15wt% FeO, 0.5wt% B2O3, 0.35wt% ZrO2, and 1.0wt% TiO2.

[0083] (5) Polish both sides of the glass with an iron reduction index of 1 in step (4) to a surface roughness Ra of 0.1 μm, so that no impurities remain on the surface. Then, measure the absorption spectrum of the glass before and after irradiation in the 200-1300 nm band by a spectrophotometer, and record the Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is 2.4008, and the absorbance at 520 nm in the absorption spectrum is 0.1874. At the same time, the thickness of the glass to be tested is measured to be 1.030 cm using a high-precision thickness measuring tool.

[0084] The glass with an iron reduction index of 1 is used as a standard sample, and then =1 is substituted into the iron reduction index and Fe 2 + The product of the extinction coefficient and the total iron concentration is used to calculate K Fe2+ =2.1489 cm -1 .

[0085] (6) Substitute the absorbance of the glass to be tested obtained in step (2) and the K obtained in step (5) Fe2+ Substitute the iron reduction index and Fe 2+ From the relationship formula of the product of the extinction coefficient and the total iron concentration, it can be seen that the iron reduction index in the glass to be tested before irradiation is 0.2072, and the iron reduction index in the glass to be tested after irradiation is 0.2175.

Claims

1. A method for testing the change of iron reduction index in glass before and after irradiation, characterized in that: First, the absorption spectra of the glass before and after irradiation in the 200~1300 nm range were measured by spectrophotometer, and then the Fe 2+ absorbance at a characteristic wavelength of 1055 nm in the absorption spectrum and absorbance at 520 nm in the absorption spectrum; wherein the glass comprises iron oxide; The absorbance at 520 nm in the absorption spectrum was used as the baseline absorbance to obtain the iron reduction index and Fe 2+ The relationship between the extinction coefficient and the product of the total iron concentration is used to calculate the change rate of the iron reduction index in the glass before and after irradiation; The iron reduction index refers to the Fe content in the glass 2+ The ratio of the concentration to the total iron concentration; Iron reduction index and Fe 2+ The relationship formula of the product of the extinction coefficient and the total iron concentration is: ; in, is the iron reduction index, dimensionless; Fe 2+ The absorbance at the characteristic band of 1055 nm in the absorption spectrum is dimensionless; is the absorbance at 520 nm in the absorption spectrum, dimensionless; K Fe2+ Fe 2+ The product of the extinction coefficient and the total iron concentration, cm -1 ; L is the glass thickness, cm; The calculation method is: take the glass with an iron reduction index of 1 as the standard sample, and then =1 is substituted into the iron reduction index and Fe 2+ The product of the extinction coefficient and the total iron concentration is used to calculate K Fe2+ ; Among them, the content of each element in the raw materials of the glass with an iron reduction index of 1 is exactly the same as that of the test sample.

2. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 1, characterized in that: The preparation method of glass with an iron reduction index of 1 is as follows: placing glass raw materials in a furnace with a nitrogen or inert gas atmosphere, heating to the melting temperature of the glass and maintaining the temperature until the glass raw materials are uniformly melted, then pouring the glass into a mold and annealing in an annealing furnace until the internal stress of the glass is eliminated, thereby obtaining glass with an iron reduction index of 1.

3. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 1, characterized in that: The measurement range of the spectrophotometer is from 200 to 1300 nm.

4. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 1, characterized in that: The raw materials of the glass consist of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO.

5. The method for testing the change of iron reduction index in glass before and after irradiation according to claim 4, characterized in that: When the raw materials of glass consist of 72 wt% SiO2, 14 wt% Na2O, 13 wt% CaO and 1 wt% FeO, =7.7057cm -1 .

Images