A method for predicting the solubility of molybdenum in borosilicate glass and its application

Abstract

The present invention proposes a method for predicting the solubility of molybdenum in borosilicate glass and its application, which belongs to the technical field of nuclear waste solidification treatment. The method comprises the following steps: S1, obtaining the oxide components of the borosilicate glass; S2, predicting the molybdenum solubility of the borosilicate glass according to the formula #imgabs0#; wherein #imgabs1# is the molybdenum solubility in the borosilicate glass, and #imgabs2# is the molybdenum solubility in the borosilicate glass. i The influence coefficient of the oxide component on the solubility of molybdenum, #imgabs3# is the first oxide component in the borosilicate glass. i The prediction method provided by the present invention can quickly and accurately predict the solubility of molybdenum in borosilicate glass. The glass composition can be adjusted based on the predicted value to obtain a nuclear waste glass composition ratio with optimal molybdenum solubility, reducing the time and money costs of trial-and-error formulation development.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear waste solidification treatment, and in particular relates to a method for predicting the solubility of molybdenum in borosilicate glass and its application. Background Art

[0002] With the rapid development of nuclear power, nuclear waste generated by spent fuel reprocessing continues to accumulate. High-level liquid waste, due to its high radioactivity levels and significant environmental hazards, poses a critical challenge to the sustainable development of nuclear power. Vitrification, a process that combines high-level liquid waste with a glass substrate through high-temperature calcination and melting to form a stable glass solid, is currently a widely accepted and developed method for treating high-level liquid waste worldwide. By immobilizing radionuclides within a flexible glass network, it achieves atomic-scale solidification of various toxic elements, preventing their migration into the external environment. Borosilicate glass has become the preferred substrate for vitrification technology due to its excellent physical and chemical stability and low melting temperature.

[0003] However, the composition of high-level radioactive liquid waste is relatively complex, and it contains a variety of elements with low solubility in borosilicate glass. Among them, molybdenum, as the main nuclear fission product, is generally present in high-level liquid waste generated during the reprocessing of spent fuel with a burn-up of 45,000 MWd / tU and above, with a content of more than 10wt% (in terms of MoO3), but its solubility in borosilicate glass is generally less than 3wt%. When molybdenum is supersaturated in the glass, it will precipitate from the glass network in the form of molybdate to form a "yellow phase". The "yellow phase" is mainly composed of alkali metal molybdates, and also contains a small amount of chromates, sulfates and some radioactive nuclides (such as 90 Sr and 137 Cs, etc.). In addition, the "yellow phase" is easily soluble in water. Once precipitated, it is very likely to cause radionuclides to migrate to the external environment, leading to nuclear safety accidents.

[0004] Current research on vitrification formulations for high-level radioactive waste from high-burnup reactors (HLW) primarily focuses on improving the solubility of borosilicate glass for MoO₃. However, this research often relies on literature and empirical evidence. Initially, a rough glass formulation is designed, followed by glass melting experiments and the preparation of vitrified samples. Performance tests are then conducted and the formulation adjusted based on the results. This process is repeated until a nuclear waste product glass that meets process and disposal standards is achieved. This entire development process is plagued by long experimental cycles and high costs, severely hindering the efficiency of formula development for vitrification of HLW from high-burnup reactors. Summary of the Invention

[0005] In view of this, the present invention proposes a method for predicting the solubility of molybdenum in borosilicate glass and its application. This prediction method can quickly and accurately predict the solubility of nuclear waste glass in molybdenum oxide based on a given borosilicate glass composition. At the same time, the glass composition can be adjusted according to this prediction method to obtain a glass ratio composition with optimal molybdenum solubility, thereby reducing the time and money costs of trial-and-error formula development.

[0006] The technical solution of the present invention is achieved as follows:

[0007] In a first aspect, the present invention provides a method for predicting the solubility of molybdenum in borosilicate glass, comprising the following steps:

[0008] S1. Obtaining oxide components of borosilicate glass;

[0009] S2, according to the formula , predicting the molybdenum solubility of the borosilicate glass;

[0010] Where, is the predicted value of the molybdenum solubility of the borosilicate glass, The borosilicate glass i The influence coefficient of the oxide components on the solubility performance of molybdenum, The borosilicate glass i The mass fraction of the oxide components.

[0011] The deviation between the predicted and measured molybdenum solubility values is <±20%.

[0012] Establishing a formula research method based on the glass "composition-performance" model and transitioning from the traditional "empirical" and "trial-and-error" methods to a "combination of model prediction and calculation + experimental verification" research method can greatly improve the efficiency of nuclear waste glass solidification formula development and reduce research costs.

[0013] On the basis of the above technical solution, further, the oxide components of the borosilicate glass, calculated by mass fraction, include 35~55% SiO2, 5~20% B2O3, 0~10% Al2O3, 0~10% CaO, 5~18% Na2O, 0~5% Li2O, 0~5% transition metal oxide additives and 12~20% other components.

[0014] On the basis of the above technical solution, further, the oxide components of the borosilicate glass, calculated by mass fraction, include 45~55% SiO2, 5~14.5% B2O3, 1~5% Al2O3, 3~10% CaO, 10~18% Na2O, 0.1~2.5% Li2O, 0.1~2.0% transition metal oxide additives and 12~20% other components.

[0015] On the basis of the above technical scheme, further, the influence coefficient of SiO2 on the solubility performance of molybdenum is 1.0, the influence coefficient of B2O3 on the solubility performance of molybdenum is 4.0, the influence coefficient of Al2O3 on the solubility performance of molybdenum is -3.5, the influence coefficient of CaO on the solubility performance of molybdenum is -1.5, the influence coefficient of Na2O on the solubility performance of molybdenum is -1.5, the influence coefficient of Li2O on the solubility performance of molybdenum is 3.5, the influence coefficient of transition metal oxides on the solubility performance of molybdenum is 2.0, and the influence coefficient of the remaining components on the solubility performance of molybdenum is 4.5.

[0016] Furthermore, the various oxide components in the glass The value is obtained by collecting a series of glass formula compositions and corresponding molybdenum solubility performance data within the applicable range, taking the content of each oxide as the independent variable and the molybdenum solubility performance parameter as the dependent variable, and obtaining it through linear fitting.

[0017] The various oxide components in the borosilicate glass The values are shown in Table 1 below.

[0018] For a given glass composition, it is only necessary to compare the mass fraction of each oxide component with the corresponding The predicted value of molybdenum solubility of the glass can be obtained by multiplying and adding the values together and performing natural logarithm transformation.

[0019] Table 1 Oxide components value

[0020]

[0021] On the basis of the above technical solution, further, the transition metal oxide includes ZnO and V2O5, and the remaining components include multiple ones of BaO, ZrO2, La2O3, Nd2O3, CeO2, MoO3, Cs2O, Fe2O3, NiO, Cr2O3, TeO2, Rb2O, MnO and SrO.

[0022] On the basis of the above technical solution, further, the molybdenum solubility is the maximum value of the molybdenum oxide content that can be dissolved in the borosilicate glass when the molybdenum oxide in the borosilicate glass reaches saturation under the melting condition of 1150°C.

[0023] In a second aspect, the present invention provides an application of the above prediction method in the formulation design of borosilicate high-radiation glass.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention provides a simple and fast method for predicting the molybdenum solubility capacity of borosilicate nuclear waste glass. By simply inputting the main chemical composition of the glass formula, the molybdenum solubility capacity of the glass formula in the waste can be quickly and accurately predicted.

[0026] (2) Through the prediction of the model of the present invention, the chemical composition of glass with better performance can be designed quickly and accurately, providing technical guidance for the development of nuclear waste glass solidification formula.

[0027] (3) The development of a nuclear waste glass solidification formula through this model can save a lot of experimental time and trial-and-error costs compared to traditional methods. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0029] Example 1

[0030] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. Given a borosilicate waste glass, the glass comprises the following oxide composition by mass: 45.5% SiO2, 13.0% B2O3, 11.5% Na2O, 2.0% Li2O, 4.0% Al2O3, 5.0% CaO, 1.5% V2O5, 2.0% BaO, 2.5% ZrO2, 2.0% La2O3, 1.5% CeO2, 2.5% MoO3, 0.5% Cr2O3, 1.0% Fe2O3, 0.5% NiO, 0.2% Rb2O, 0.3% Y2O3, 0.5% TeO2, 2.0% Nd2O3, 0.5% MnO, 1.0% Cs2O, and 0.5% SrO.

[0031] The composition of the waste glass is within the applicable range of the prediction method. The solubility of the borosilicate glass in molybdenum oxide obtained by the above prediction method is 4.4 wt %.

[0032] A high-level radioactive waste glass batch was prepared according to the above proportions, with SiO₂, B₂O₃, Al₂O₃, ZrO₂, La₂O₃, Nd₂O₃, CeO₂, MoO₃, Fe₂O₃, NiO, Cr₂O₃, TeO₂, and MnO introduced as oxides, and the remaining components introduced as carbonates. The batch was mixed thoroughly and melted in a high-temperature furnace at 1150°C for 2 hours. The molten glass was quenched in air and then annealed in a heat treatment furnace at 450°C for 2 hours. After annealing and cooling, a waste glass sample was obtained. The waste glass sample was crushed into a powder, remelted at 1150°C for 1 hour by adding 5 wt% molybdenum oxide, and quenched to obtain a molybdenum-saturated glass solid. The glass solid was ground into a fine powder, and the undissolved molybdenum oxide in the glass solid was thoroughly washed away. Compositional analysis determined the effectively dissolved molybdenum oxide content in the glass solid to be 4.5 wt%, which deviated from the predicted value by approximately 2%.

[0033] Example 2

[0034] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. The specific operation is the same as that of Example 1, except that, to improve the solubility of waste glass in molybdenum oxide, the following components are adjusted based on the predicted molybdenum solubility values while keeping the contents of the other components unchanged. The following components are adjusted, calculated by oxide mass fraction, to be: 46.0% SiO2, 14.5% B2O3, 11.5% Na2O, 2.5% Li2O, 5.0% Al2O3, 3.0% CaO, 1.0% V2O5, and 1.0% BaO.

[0035] The solubility of the borosilicate glass in molybdenum oxide obtained by the above prediction method is 4.6 wt %.

[0036] The molybdenum oxide effectively dissolved in the glass solidified sample was detected to be 4.8wt%, with a deviation of <5% from the predicted value, and the glass formula's ability to dissolve molybdenum was improved.

[0037] Example 3

[0038] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. The specific operation is the same as that of Example 1, except that, to further improve the solubility of waste glass for molybdenum oxide, the following components are adjusted based on the predicted molybdenum solubility values while keeping the contents of the other components unchanged: 47.5% SiO2, 14.5% B2O3, 10.0% Na2O, 2.5% Li2O, 3.5% Al2O3, 0.5% V2O5, 1.0% BaO, and 5.0% CaO, calculated by oxide mass fraction.

[0039] The solubility of the borosilicate glass in molybdenum oxide obtained by the above prediction method is 4.8 wt %.

[0040] The molybdenum oxide effectively dissolved in the glass solidified sample was detected to be 5.1wt%, with a deviation of <10% from the predicted value, and the glass formula's ability to dissolve molybdenum was further improved.

[0041] Example 4

[0042] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. The specific operation is the same as that of Example 1, except that the following components are adjusted while keeping the contents of the other components unchanged. The following components are adjusted, calculated as oxide mass fractions: 46.0% SiO2, 13.5% B2O3, 11.5% Na2O, 2.0% Li2O, 5.0% Al2O3, 5.5% CaO, 0.0% V2O5, and 1.0% BaO.

[0043] The composition of the waste glass is within the applicable range of the prediction method. The prediction method calculates that the solubility of the borosilicate glass in molybdenum oxide is 4.0 wt %, which has no effect on improving the solubility of molybdenum oxide.

[0044] The content of molybdenum oxide effectively dissolved in the glass solidified body sample was detected to be 4.4 wt %, which deviated from the predicted result by about 10%.

[0045] Example 5

[0046] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. The specific operation is the same as that of Example 1, except that: a given borosilicate waste glass includes the following oxide composition by mass fraction: 55.0% SiO2, 5.0% B2O3, 18.0% Na2O, 10.0% CaO, 0.7% BaO, 1.8% ZrO2, 1.5% La2O3, 1.1% CeO2, 1.8% MoO3, 0.4% Cr2O3, 0.7% Fe2O3, 0.4% NiO, 0.1% Rb2O, 0.2% Y2O3, 0.3% TeO2, 1.5% Nd2O3, 0.4% MnO, 0.7% Cs2O, and 0.4% SrO.

[0047] The solubility of molybdenum oxide in borosilicate glass was calculated to be 2.6 wt % by weight using a prediction method.

[0048] The molybdenum oxide effectively dissolved in the glass solidified body sample was detected to be 2.7 wt %, with a deviation of <5% from the predicted value.

[0049] Example 6

[0050] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. The specific operation is the same as that of Example 1, except that: a given borosilicate waste glass includes the following oxide composition by mass fraction: 35.0% SiO2, 20.0% B2O3, 5.0% Na2O, 5.0% Li2O, 10.0% Al2O3, 5.0% V2O5, 1.2% BaO, 3.0% ZrO2, 2.4% La2O3, 1.8% CeO2, 3.0% MoO3, 0.6% Cr2O3, 1.2% Fe2O3, 0.6% NiO, 0.3% Rb2O, 0.5% Y2O3, 0.6% TeO2, 2.4% Nd2O3, 0.6% MnO, 1.2% Cs2O, and 0.6% SrO.

[0051] The solubility of molybdenum oxide in borosilicate glass was calculated to be 7.3 wt % by weight using a prediction method.

[0052] The molybdenum oxide effectively dissolved in the glass solidified body sample was detected to be 6.5 wt %, with a deviation of <15% from the predicted value.

[0053] Comparative Example 1

[0054] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. The specific operation is the same as that of Example 1, except that: a given borosilicate waste glass includes the following oxide composition by mass fraction: 36.0% SiO2, 16.0% B2O3, 8.0% Na2O, 28.0% Al2O3, 4.0% CaO, 0.5% BaO, 1.2% ZrO2, 1.0% La2O3, 0.7% CeO2, 1.2% MoO3, 0.2% Cr2O3, 0.5% Fe2O3, 0.2% NiO, 0.1% Rb2O, 0.2% Y2O3, 0.3% TeO2, 1.0% Nd2O3, 0.2% MnO, 0.5% Cs2O, and 0.2% SrO.

[0055] The Al2O3 content in the waste glass composition exceeds the applicable range of the prediction method. The solubility of the borosilicate glass in molybdenum oxide calculated by the prediction method is 1.1 wt%.

[0056] The molybdenum oxide effectively dissolved in the glass solidified body sample was detected to be 8.0 wt %, and the deviation between the predicted value and the measured value was greater than 90%.

[0057] Comparative Example 2

[0058] This embodiment provides a method for predicting the solubility of molybdenum in borosilicate glass. The specific operation is the same as that of Example 1, except that: a given borosilicate waste glass includes the following oxide composition by mass fraction: 37.0% SiO2, 19.0% B2O3, 13.0% Na2O, 23.0% CaO, 0.5% BaO, 1.2% ZrO2, 1.0% La2O3, 0.7% CeO2, 1.2% MoO3, 0.2% Cr2O3, 0.5% Fe2O3, 0.2% NiO, 0.1% Rb2O, 0.2% Y2O3, 0.3% TeO2, 1.0% Nd2O3, 0.2% MnO, 0.5% Cs2O, and 0.2% SrO.

[0059] The CaO content in the waste glass composition exceeds the applicable range of the prediction method. The solubility of the borosilicate glass in molybdenum oxide calculated by the prediction method is 2.4 wt%.

[0060] The molybdenum oxide effectively dissolved in the glass solidified body sample was detected to be 6.5 wt %, and the deviation between the predicted value and the measured value was greater than 60%.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for predicting the solubility of molybdenum in borosilicate glass, characterized in that: The following steps are involved: S1. Obtaining oxide components of borosilicate glass; S2, according to the formula , predicting the molybdenum solubility of the borosilicate glass; Where, is the molybdenum solubility of the borosilicate glass, The borosilicate glass i The influence coefficient of the oxide components on the solubility performance of molybdenum, The borosilicate glass i The mass fraction of the oxide components.

2. The method for predicting the solubility of molybdenum in borosilicate glass according to claim 1, wherein: The oxide components of the borosilicate glass, calculated by mass fraction, include 35-55% SiO2, 5-20% B2O3, 0-10% Al2O3, 0-10% CaO, 5-18% Na2O, 0-5% Li2O, 0-5% transition metal oxide additives and 12-20% remaining components, wherein the transition metal oxide additives include V2O5 and ZnO, and the remaining components include multiple ones of BaO, ZrO2, La2O3, Nd2O3, CeO2, MoO3, Cs2O, Fe2O3, NiO, Cr2O3, TeO2, Rb2O, MnO and SrO.

3. The method for predicting the solubility of molybdenum in borosilicate glass according to claim 1, wherein: The oxide components of the borosilicate glass, calculated by mass fraction, include 45-55% SiO2, 5-14.5% B2O3, 1-5% Al2O3, 3-10% CaO, 10-18% Na2O, 0.1-2.5% Li2O, 0.1-2.0% transition metal oxide additives and 12-20% remaining components, wherein the transition metal oxide additives include V2O5 and ZnO, and the remaining components include multiple types of BaO, ZrO2, La2O3, Nd2O3, CeO2, MoO3, Cs2O, Fe2O3, NiO, Cr2O3, TeO2, Rb2O, MnO and SrO.

4. A method for predicting the solubility of molybdenum in borosilicate glass according to claim 2 or 3, characterized in that: The influence coefficient of SiO2 on the solubility performance of molybdenum is 1.0, the influence coefficient of B2O3 on the solubility performance of molybdenum is 4.0, the influence coefficient of Al2O3 on the solubility performance of molybdenum is -3.5, the influence coefficient of CaO on the solubility performance of molybdenum is -1.5, the influence coefficient of Na2O on the solubility performance of molybdenum is -1.5, the influence coefficient of Li2O on the solubility performance of molybdenum is 3.5, the influence coefficient of transition metal oxide additives on the solubility performance of molybdenum is 2.0, and the influence coefficient of other components on the solubility performance of molybdenum is 4.

5.

5. The method for predicting the solubility of molybdenum in borosilicate glass according to claim 1, wherein: The molybdenum solubility is the maximum value of the molybdenum oxide content that can be dissolved in the borosilicate glass when the molybdenum oxide in the borosilicate glass reaches saturation under the melting condition of 1140° C. to 1160° C.

6. Application of the prediction method according to any one of claims 1 to 5 in the formulation design of borosilicate high-energy glass.

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