CN110590161B

CN110590161B - Adding V2O5Method for improving solubility of molybdenum oxide in glass ceramic solidified body

Info

Publication number: CN110590161B
Application number: CN201910956651.0A
Authority: CN
Inventors: 张行泉; 霍冀川; 连启会; 朱永昌
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2019-10-10
Filing date: 2019-10-10
Publication date: 2022-02-15
Anticipated expiration: 2039-10-10
Also published as: CN110590161A

Abstract

The invention discloses a V-adding agent₂O₅To improve the solubility of molybdenum oxide in a glass-ceramic solidified body, the glass-ceramic solidified body comprising: SiO 2₂、B₂O₃、Na₂O、Al₂O₃、Gd₂O₃、CaO、MoO₃And V₂O₅(ii) a The preparation method comprises the following steps: with SiO₂、H₃BO₃、Na₂CO₃、CaCO₃、Al₂O₃、Gd₂O₃、MoO₃、NH₄VO₃Uniformly mixing the raw materials by adopting a ball milling method; wherein, MoO is used₃Simulating radioactive waste containing molybdenum; the method comprises the steps of preparing a glass ceramic solidified body in a high-temperature box furnace by using a secondary melting heat treatment method and using a corundum crucible to contain ball-milled raw materials, wherein the melting procedure of the preparation is that the raw materials are calcined at 850-900 ℃, then are melted at 1250-1300 ℃, then are quenched and cast on a steel plate to obtain glass frits, and the glass frits are crushed, screened, secondarily melted at high temperature and finally poured to obtain the glass ceramic solidified body. The invention adds low levels of V to the glass composition₂O₅Can obviously increase MoO₃Solubility in boroaluminosilicate glasses.

Description

Adding V2O5Method for improving solubility of molybdenum oxide in glass ceramic solidified body

Technical Field

The invention belongs to the treatment and disposal of radioactive waste, and relates to a V additive₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body is suitable for solidification treatment of radioactive waste containing molybdenum discharged in the fields of nuclear industry and the like.

Background

Nuclear energy is an efficient, convenient and abundant energy source, and the utilization of nuclear energy is a necessary choice for human survival and social development. Compared with fossil energy combustion in a thermal power plant, nuclear energy releases a large amount of energy through fission reaction to generate electricity, sulfur dioxide cannot be generated to pollute air, and carbon dioxide cannot be generated to cause greenhouse effect. Compared with wind energy, solar energy and the like, the nuclear energy occupies a small area. The fuel used by the nuclear power plant has low energy density, so the volume of the fuel is small and the transportation is convenient.

With the rapid development of social science and technology, nuclear energy will gradually replace fossil energy, and the amount of flooding fuel discharged from nuclear reactors is gradually increased every year. However, the great advantages of nuclear energy are still not prevented from building and developing nuclear power projects. The disposal of radioactive waste is a crucial link in nuclear energy safety, and nuclear energy development can be developed to the best extent only if the radioactive waste is properly treated. Therefore, how to isolate radioactive waste from the biosphere where humans live has become a primary concern in the development of nuclear energy.

Because the components of the high-level radioactive waste liquid are determined by the type of reactor materials, the post-treatment process of spent fuel and the like, the components of the high-level radioactive waste liquid have great difference, which leads to the need of developing a glass ceramic solidified body formula suitable for the characteristics of the high-level radioactive waste liquid when the high-level radioactive waste liquid is solidified by glass. Although borosilicate glass systems have been extensively studied and used in the vitrification process of nuclear waste, there are still many problems in their application, such as the low solubility of some abundant elements in nuclear waste in the glass system. These elements are incompatible with the glass matrix constituents and phase segregation or devitrification of the glass melt occurs when the content of these elements exceeds their solubility in the glass. This is typically the dissolution of molybdenum in the nuclear waste glass. Some high-level nuclear wastes often contain large amounts of molybdenum due to nuclear reactor process characteristics. These molybdenum are derived from used 235U nuclear fuel, in metallic form or in oxide form. Whereas the molybdenum therein is generally converted to cesium phosphomolybdate and zirconium molybdate precipitates after dissolution, aggregation and evaporation of the nuclear waste. The solubility of molybdate in the traditional nuclear waste glass is very low (less than or equal to 1 wt%), and excessive molybdate can cause the internal of the nuclear waste glass to be uneven to form phase separation. These phases are not radioactive in themselves but may contain some radioactive elements such as⁹⁰Sr and¹³⁷cs, and these separated phases tend to have high water solubility. Therefore, if contacting with water, the radioactive elements in the water will be very likely to beInto the environment. At the same time, these phase separations are also corrosive, which can greatly reduce the efficiency and life of the nuclear waste vitrification melters. Thus, the low solubility of molybdate in the treatment of molybdenum-rich high-level nuclear waste greatly limits the processing power of conventional borosilicate nuclear waste glass.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.

To achieve these objects and other advantages in accordance with the purpose of the invention, an additive V is provided₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following components in percentage by mole:

40～60mol％SiO₂、10～15mol％B₂O₃、8～13mol％Na₂O、1.5～3.5mol％ Al₂O₃、0.1～0.2mol％Gd₂O₃、8～13mol％CaO、1～3mol％MoO₃、 0.6～4.2mol％V₂O₅。

the invention also provides an additive V₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following components in percentage by mole:

58.68mol％SiO₂、13.84mol％B₂O₃、11.26mol％Na₂O、2.85mol％Al₂O₃、 0.15mol％Gd₂O₃、11.22mol％CaO、2mol％MoO₃、xmol％V₂O₅；

wherein, when xmol% V₂O₅When the value of x is 0.6-4.2, 58.68 mol% SiO₂、 13.84mol％B₂O₃、11.26mol％Na₂O、2.85mol％Al₂O₃、0.15mol％Gd₂O₃11.22 mol% CaO and 2 mol% MoO₃The mole percentage of (b) is taken as a value by an integral sacrificial method, namely 1-x% of the original mole percentage is taken.

The invention also providesAdding V₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following components in percentage by mole:

58.09mol％SiO₂、13.70mol％B₂O₃、11.14mol％Na₂O、2.82mol％Al₂O₃、0.15mol％Gd₂O₃、11.1mol％CaO、ymol％MoO₃、3mol％V₂O₅；

wherein when ymol% MoO₃When the value of y is 2.0-2.5, 58.09 mol% SiO₂、 13.70mol％B₂O₃、11.14mol％Na₂O、2.82mol％Al₂O₃、0.15mol％Gd₂O₃11.1 mol% CaO and 3 mol% V₂O₅The mole percentage of (b) is taken as a value by an integral sacrificial method, namely 1-y% of the original mole percentage is taken.

The invention also provides an additive V₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following steps:

step one, the mol percentage of the raw materials is SiO₂、H₃BO₃、Na₂CO₃、CaCO₃、Al₂O₃、Gd₂O₃、 MoO₃、NH₄VO₃Weighing the raw materials, uniformly mixing the raw materials by adopting a ball milling method, and carrying out ball milling for 20-25 min; wherein, MoO is used₃Simulating radioactive waste containing molybdenum;

and step two, adopting a secondary melting heat treatment method, preparing a glass ceramic solidified body by using the raw materials of the corundum crucible after ball milling in a high-temperature box type furnace, wherein the melting procedure of the preparation is that the raw materials are calcined at 850-900 ℃, then melted at 1250-1300 ℃, then quenched and cast on a steel plate to obtain glass frits, crushing the glass frits, sieving the glass frits by a 200-mesh sieve, carrying out secondary melting at 1250-1300 ℃, and finally pouring to obtain the glass ceramic solidified body.

Preferably, the process of uniformly mixing the raw materials by the ball milling method comprises the following steps: adding the raw materials and the process control agent into a ball milling tank, adding ball milling balls, placing on a planetary ball mill, performing wet ball milling mixing, and then drying to obtain uniformly mixed raw materials; the ball-milling ball adopts ceramic balls, the diameter of a big ball is about 6mm, the diameter of a small ball is about 3mm, and the mass ratio of the big ball to the small ball is 1: 2, the ball material ratio, namely the weight ratio of the ball grinding balls to the raw materials is 10: 1, ball milling at a rotating speed of 100-120 r/min; the process control agent is one or a mixture of more than two of absolute ethyl alcohol, imidazoline, normal hexane and stearic acid, and the adding volume accounts for 20-30% of the volume of the ball milling tank.

Preferably, the temperature raising process in the second step is as follows: adopting a secondary melting heat treatment method, preparing a glass ceramic solidified body by using a corundum crucible and ball-milled raw materials in a high-temperature box furnace, wherein the melting procedure of the preparation is as follows: heating to 400-600 ℃ at the speed of 5-10 ℃/min, carrying out heat preservation calcination for 30-45 min, heating to 850-900 ℃ at the speed of 3-5 ℃/min, carrying out heat preservation calcination for 60-90 min, heating to 1000-1100 ℃ at the speed of 1-2 ℃/min, carrying out heat preservation melting for 30-45 min, continuously heating to 1250-1300 ℃ at the speed of 1-2 ℃/min, carrying out heat preservation melting for 60-120 min, carrying out quenching casting on a steel plate to obtain glass frit, crushing the glass frit, sieving by a 200-mesh sieve, heating to 1250-1300 ℃ at the speed of 5-10 ℃/min, carrying out secondary melting for 1-3 h, and finally pouring to obtain the glass ceramic solidified body. .

The invention at least comprises the following beneficial effects:

(1) adding low levels of V to glass compositions₂O₅Can obviously increase MoO₃Solubility in boroaluminosilicate glasses.

(2) DSC curve shows the glass transition temperature with V₂O₅The increase and the decrease of the doping amount show that V₂O₅The incorporation of (2) causes the glass network structure to be altered.

(3) XRD, Raman spectroscopy and SEM data reflect MoO₃And a tendency of crystallization of the solidified body, and provides information on microstructure of the solidified body. Within a certain range, with V₂O₅Increase in the amount of incorporation, CaMoO₄Gradually decrease in phase separation (0 to 1.2 mol% V)₂O₅) Until disappearance (V is more than or equal to 1.8mol percent₂O₅) Tetrahedron [ MoO ] in the glass phase₄]^2-Gradually increasing. Raman spectrum shows more microscopic internal structure of solidified body, combined with XRD, proposes [ VO₄]^3-And [ MoO ]₄]^2-The interaction mechanism of (a). It is believed that the charge compensation mechanism causes Na in the glass⁺And Ca²⁺Ions are dispersed, thereby inhibiting CaMoO₄Phase separation of (2).

(4) Although the DSC curve shows V₂O₅The glass network structure is changed by the doping, but the chemical stability of the solidified body is tested (PCT), and the element normalized leaching rate is very low, the leaching resistance effect is good, and the chemical stability is good.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Description of the drawings:

FIG. 1 is an XRD pattern of a glass-ceramic cured body prepared in examples 1 to 5 of the present invention and comparative example 1;

FIG. 2 shows the present invention V_x-M₂Two extreme samples of the series (V)₀-M₂Comparative examples 1 and V_4.2-M₂-raman spectrum of example 5);

FIG. 3 is a Raman spectrum of a glass-ceramic cured body prepared in examples 1 to 5 of the present invention and comparative example 1;

FIG. 4 is a Raman spectrum of a glass-ceramic cured body prepared in examples 3 to 5 of the present invention;

FIG. 5 is an SEM photograph of glass-ceramic solidified bodies prepared in examples 1 to 3 of the present invention and comparative example 1;

FIG. 6 is a DSC chart of the glass-ceramic cured bodies prepared in examples 1 to 5 of the present invention and comparative example 1;

FIG. 7 is an XRD pattern of a glass-ceramic cured body prepared in examples 6 to 8 of the present invention;

FIG. 8 is a Raman spectrum of a glass-ceramic cured body prepared in examples 6 to 8 of the present invention;

FIG. 9 is a graph showing a normalized leaching rate of Si element in 28 days for the cured glass-ceramics prepared in examples 1 to 5 of the present invention and comparative example 1;

FIG. 10 is a graph showing a normalized leaching rate of Ca element in 28 days for the cured glass-ceramics according to examples 1 to 5 of the present invention and comparative example 1;

FIG. 11 is a graph showing a normalized leaching rate of Mo element in 28 days for the glass-ceramic solidified bodies prepared in examples 1 to 5 of the present invention and comparative example 1;

FIG. 12 is a graph showing a normalized leaching rate of V element in 28 days for the cured glass-ceramics prepared in examples 1 to 5 of the present invention and comparative example 1.

The specific implementation mode is as follows:

the present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

Example 1:

adding V₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following components in percentage by mole:

58.32792mol％SiO₂、13.75696mol％B₂O₃、11.19244mol％Na₂O、 2.8329mol％Al₂O₃、0.1491mol％Gd₂O₃、11.15268mol％CaO、1.988mol％MoO₃、 0.6mol％V₂O₅；

the adding V₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following steps:

step one, the mol percentage of the raw materials is SiO₂、H₃BO₃、Na₂CO₃、CaCO₃、Al₂O₃、Gd₂O₃、 MoO₃、NH₄VO₃Weighing the raw materials, uniformly mixing the raw materials by adopting a ball milling method, and carrying out ball milling for 20 min; wherein, MoO is used₃Simulating radioactive waste containing molybdenum;

step two, adopting a secondary melting heat treatment method, preparing a glass ceramic solidified body in a high-temperature box type furnace by using the raw materials of the corundum crucible after ball milling, wherein the melting procedure of the preparation is as follows: heating to 400 ℃ at the speed of 5 ℃/min, carrying out heat preservation calcination for 45min, heating to 850 ℃ at the speed of 3 ℃/min, carrying out heat preservation calcination for 90min, heating to 1100 ℃ at the speed of 2 ℃/min, carrying out heat preservation melting for 45min, continuously heating to 1300 ℃ at the speed of 2 ℃/min, carrying out heat preservation melting for 120min, carrying out quenching casting on a steel plate to obtain glass frit, crushing the glass frit, sieving by a 200-mesh sieve, heating to 1300 ℃ at the speed of 10 ℃/min, carrying out secondary melting for 3h, and finally pouring to obtain a glass ceramic solidified body;

the process of uniformly mixing the raw materials by the ball milling method comprises the following steps: adding the raw materials and the process control agent into a ball milling tank, adding ball milling balls, placing on a planetary ball mill, performing wet ball milling mixing, and then drying to obtain uniformly mixed raw materials; the ball-milling ball adopts ceramic balls, the diameter of a big ball is about 6mm, the diameter of a small ball is about 3mm, and the mass ratio of the big ball to the small ball is 1: 2, the ball material ratio, namely the weight ratio of the ball grinding balls to the raw materials is 10: 1, ball milling rotating speed is 120 r/min; the process control agent is one or a mixture of more than two of absolute ethyl alcohol, imidazoline, normal hexane and stearic acid, and the adding volume accounts for 20% of the volume of the ball milling tank;

example 2:

57.97584mol％SiO₂、13.67392mol％B₂O₃、11.12488mol％Na₂O、 2.8158mol％Al₂O₃、0.1482mol％Gd₂O₃、11.08536mol％CaO、1.976mol％MoO₃、 1.2mol％V₂O₅；

an addition as described aboveV₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following steps:

example 3:

adding V₂O₅A method for increasing the solubility of molybdenum oxide in a glass-ceramic solidified body, the glass-ceramic solidified body comprising the following components in mole percent:

57.62376mol％SiO₂、13.59088mol％B₂O₃、11.05732mol％Na₂O、 2.7987mol％Al₂O₃、0.1473mol％Gd₂O₃、11.01804mol％CaO、1.964mol％MoO₃、 1.8mol％V₂O₅；

example 4:

56.9196mol％SiO₂、13.4248mol％B₂O₃、10.9222mol％Na₂O、2.7645mol％ Al₂O₃、0.1455mol％Gd₂O₃、10.8834mol％CaO、1.94mol％MoO₃、3mol％V₂O₅；

example 5:

56.21544mol％SiO₂、13.25872mol％B₂O₃、10.78708mol％Na₂O、 2.7303mol％Al₂O₃、0.1437mol％Gd₂O₃、10.74876mol％CaO、1.916mol％ MoO₃、4.2mol％V₂O₅；

comparative example 1:

a molybdenum-containing radioactive waste glass-ceramic solidified body, comprising the following components in mole percent:

58.68mol％SiO₂、13.84mol％B₂O₃、11.26mol％Na₂O、2.85mol％Al₂O₃、 0.15mol％Gd₂O₃、11.22mol％CaO、2mol％MoO₃；

the preparation method of the molybdenum-containing radioactive waste glass ceramic solidified body comprises the following steps:

step one, the mol percentage of the raw materials is SiO₂、H₃BO₃、Na₂CO₃、CaCO₃、Al₂O₃、Gd₂O₃、 MoO₃Weighing the raw materials, uniformly mixing the raw materials by adopting a ball milling method, and carrying out ball milling for 20 min; wherein, MoO is used₃Simulating radioactive waste containing molybdenum;

example 6:

56.9282mol％SiO₂、13.426mol％B₂O₃、10.9172mol％Na₂O、2.7636mol％ Al₂O₃、0.147mol％Gd₂O₃、10.878mol％CaO、2mol％MoO₃、2.94mol％V₂O₅；

example 7:

56.81202mol％SiO₂、13.3986mol％B₂O₃、10.89492mol％Na₂O、 2.75796mol％Al₂O₃、0.1467mol％Gd₂O₃、10.8558mol％CaO、2.2mol％MoO₃、 2.934mol％V₂O₅；

example 8:

56.63775mol％SiO₂、13.3575mol％B₂O₃、10.8615mol％Na₂O、 2.7495mol％Al₂O₃、0.14625mol％Gd₂O₃、10.8225mol％CaO、2.5mol％MoO₃、 2.925mol％V₂O₅；

the glass ceramic cured bodies prepared in examples 1 to 8 and comparative example 1 were subjected to the following tests:

(1) x-ray diffraction analysis: tested by X' Pert PRO type X-ray diffractometer (XRD) manufactured by PANALYtic, Netherlands. And (3) testing conditions are as follows: a Cu target,

pipe pressure 40kV and pipe flow 40 mA; continuous scanning; step length: 0.03 degree. XRD characterization is carried out on the prepared sample, and the MoO of the boron-aluminum silicate glass formula can be preliminarily determined₃The kind and degree of crystallization of the crystal phase precipitated after the solubility is exceeded are determined.

(2) And (3) Raman spectrum testing: tested by an In via type laser Raman spectrometer (Raman) manufactured by Renishaw In via, united kingdom under the following test conditions: resolution of 2cm^-1Scanning range of 200cm^-1～1200cm^-1The excitation wavelength is 514.5 nm. The Raman spectrum test of the sample can reflect the internal structure and chemical bonds of the sample and can also be used as a method for characterizing and identifying chemical species. By comparing the raman spectra of the sample and the reference, the composition of the sample is determined and can provide some structural information of the crystals not detected by XRD.

(3) And (3) characterization of micro morphology: tested by a field emission Scanning Electron Microscope (SEM) model Ultra55, produced by CarlZeiss, Germany. And (3) testing conditions are as follows: the operating voltage EHT is 15 kV. The section of the prepared sample is observed by a scanning electron microscope, and the information of the crystallization morphology, the crystal distribution condition, the structural characteristics and the like of the sample can be reflected. It will be more intuitive in this study to provide information on the devitrification tendency of the cured body in concert with XRD and Raman spectroscopy.

(4) Differential scanning calorimetry analysis: tested by a model SDTQ600 comprehensive thermal analyzer (DSC) manufactured by TA of USA. And (3) testing conditions are as follows: the heating rate is 2 ℃/min; room temperature to 1000 ℃; an air atmosphere. The DSC curve of the water quenched glass powder was measured using a thermal analyzer. To study the endothermic exotherm of this sample at the programmed temperature. By thermal analysis of the sample, V can be determined₂O₅The influence of the amount of the dopant on the glass transition temperature (Tg) can be combined with XRD, SEM and the like to further understand the crystallization type and crystallization temperature information.

(5) Chemical stability test (PCT test): to V_x-M₂The chemical stability test of the boron-aluminum silicate glass can reflect the leaching resistance of the solidified body. The sample was first crushed and sieved to 200 mesh size particles with an average particle size of 115 μm. Adding 80mL of water into 3g of sample, placing the sample into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, and carrying out chemical stability test in an oven at the temperature of 90 +/-2 ℃, wherein the fixed 1/3/7/14/28 days is the sampling time. Measuring the concentration of target elements in the leachate by adopting an American ThermoFisher-iCAP6500 inductively coupled plasma emission spectrometer under the following test conditions: and establishing a normalized leaching rate curve, and researching the influence of V doping on the chemical stability of the glass. Normalized Leaching Rate LRi (g.m)^-2.d^-1) Using equation (1) to calculate:

where Ci is the concentration of the element in the solution (g/L), the mass fraction of the element in the fi glass and glass ceramic samples, V is the volume of the leach solution (L), and S is the surface geometric area of the sample (m)²) Δ t is the duration of the experiment (d). The BET nitrogen adsorption amount was measured by using a surface area analyzer to obtain glass particles having a specific surface area of about 0.054m²(ii) in terms of/g. The S/V ratio is about 2025m^-1。

FIG. 1 shows examples 1 to 5 and comparative example 1 (V)_x-M₂Series) of the XRD patterns of the glass-ceramic solidified bodies prepared in the above; wherein, V₀-M₂The glass ceramic cured body prepared in comparative example 1, V_0.6-M₂Glass ceramic cured body prepared as representative of example 1, V_1.2-M₂Glass ceramic cured body prepared as representative example 2, V_1.8-M₂Glass ceramic cured body prepared in representative example 3, V_3.0-M₂Glass ceramic cured body prepared according to representative example 4, V_4.2-M₂Represents the glass-ceramic cured body prepared in example 5; the diffraction peaks shown in the figure are the crystalline phase CaMoO₄Characteristic peak of (a) and glass phase characteristic steamed bun peak.However, CaMoO₄Has a low diffraction intensity (V)₀-M₂～V_1.2-M₂) Only its main peak (2 θ ═ 28.8 °) can be clearly resolved. This indicates that MoO₃High solubility in the glass matrix, CaMoO₄Has a low tendency to crystallize, and forms CaMoO₄A glass-ceramic solidified body which is a microcrystalline phase. Furthermore, the intensity and relative area of the diffraction peak follow V₂O₅The content of the compound gradually decreases with increasing amount (x is 0 to 1.2 mol%, V)₂O₅) And when x is more than or equal to 1.8 mol%, no diffraction peak of the calcium molybdate crystal phase is detected, and only a glass phase characteristic steamed bun peak is detected. That is, according to the XRD pattern, no crystalline phase was formed in the sample with x.gtoreq.1.8 mol%, but only a glass phase was present. This indicates that MoO₃In this matrix, it is completely dissolved in the glassy phase and no longer forms CaMoO₄A microcrystalline phase, and the solidified body is uniform and does not separate phases. From the XRD results, it was preliminarily confirmed that a very important point was added to the glass composition in a low content of V₂O₅Can obviously increase MoO₃Solubility in boroaluminosilicate glasses and no other crystalline phase separation occurs.

FIGS. 2 to 4 show examples 1 to 5 and comparative example 1 (V)_x-M₂Series) of the glass-ceramic cured bodies prepared in the above step; wherein, V₀The glass ceramic cured body prepared in comparative example 1, V_0.6Glass ceramic cured body prepared as representative of example 1, V_1.2Glass ceramic cured body prepared as representative example 2, V_1.8Glass ceramic cured body prepared in representative example 3, V_3.0Glass ceramic cured body prepared according to representative example 4, V_4.2Represents the glass-ceramic cured body prepared in example 5;

FIG. 2a shows V_x-M₂Two extreme samples of the series (V)₀-M₂Comparative examples 1 and V_4.2-M₂Raman spectrum of example 5), Raman measurement range 200-^-1. Raman shift at 390cm^-1,793 cm^-1,846cm^-1And 878cm^-1All are reacted with CaMoO₄Tetrahedron in crystal phase[MoO4]^2-The ions are related. From FIG. 3 (FIG. 2b) we can see that these are related to CaMoO₄Peaks associated with the crystalline phase, the intensity of which follows V₂O₅Gradually decreases with increasing amount of (x is 0 to 1.2 mol%, V)₂O₅) Until it disappeared (x.gtoreq.1.8 mol%). This result is in complete agreement with the XRD results in fig. 1. At the same time, we can see that the Raman shift is 322cm^-1And 914cm^-1Nearby tetrahedron [ MoO ] with glass phase₄]^2-The ion-related peaks gradually increased in both peak intensity and peak area. These two changes together indicate a change with V₂O₅By the incorporation of [ MoO ]₄]^2-More ions are dispersed into the glass phase to reduce CaMoO₄Tendency to crystallize, thereby increasing MoO₃Solubility in boroaluminosilicate glasses.

Raman spectroscopy is very sensitive to tetrahedral anions in boroaluminosilicate glasses that are not connected to the glass network but are surrounded by network modifying cations. It can be seen from FIGS. 3 and 4 (FIGS. 2b-c) that as V is followed₂O₅Increased amount of tetrahedra [ MoO ] in the glass phase₄]^2-The ion-related Mo-O stretching vibration peak is shifted to the low wave number direction (from 914 cm)^-1To 904cm^-1). This indicates that [ MoO ] is in the glass phase₄]^2-The local environment of the ions is changed. To understand V₂O₅After incorporation, how to pair [ MoO₄]^2-It is very meaningful to propose a charge compensation mechanism when the local environment around the ions changes. We consider as V₂O₅After incorporation, high field strength V⁵⁺Ion potential pair [ MoO₄]^2-The ions are charge compensated. There is a possibility that a V-O-Mo structure is formed, the electron cloud density around Mo-O is lowered, and the absorption peak is shifted to a low wave number direction.

Furthermore, with V₂O₅The doping amount is increased, two broad peaks begin to appear, and the Raman shift is 364cm^-1And 856cm^-1And (3) the vibration is respectively related to the O-V-O bending vibration and the V-O stretching vibration in the glass phase. This is achieved byThe intensity of the two peaks follows V₂O₅Is increased. It should be noted that when the Mo — O stretching vibration mode exists in the sample, the V — O stretching vibration mode usually overlaps with the shoulder thereof, so that it is impossible to clearly compare and quantify the Mo — O stretching vibration mode. And the bending vibration mode of the O-V-O is partially overlapped with the bending vibration mode of the O-Mo-O.

FIG. 5 shows examples 1 to 3 and comparative example 1 (V)_x-M₂Series) of the glass-ceramic cured bodies prepared in the above step; wherein FIG. 5a is an SEM photograph of a glass-ceramic solidified body prepared in comparative example 1; FIG. 5b is an SEM image of a glass-ceramic solidified body prepared in example 1; FIG. 5c is an SEM image of a glass-ceramic solidified body prepared according to example 2; FIG. 5d is an SEM image of a glass-ceramic solidified body prepared according to example 3; SEM images (as in fig. 5a-d) will give a more intuitive effect. When x is 0 mol% (fig. 5a), two distinct phases (white dots and gray matrix phase) are present in the glass ceramic consolidated body. The white dots belong to CaMoO according to the combination of XRD and Raman spectrum₄The crystals, which have a size of 100-200nm, are uniformly distributed in the glassy phase matrix. When x is 0.6 to 1.2 mol% (FIG. 5b-c), CaMoO₄The crystals are uniformly dispersed in the glass phase and CaMoO₄The crystal size is almost unchanged compared to 0 mol% for x, but the amount is gradually reduced. This corresponds to CaMoO in XRD and Raman spectra₄The characteristic peaks of the crystals gradually decrease. When x.gtoreq.1.8 mol% (FIG. 5d), the sample was homogeneous and single phase, i.e., no precipitated phase was present. This corresponds to both XRD and raman spectroscopy results.

FIG. 6 shows examples 1 to 5 and comparative example 1 (V)_x-M₂Series) of the glass-ceramic cured bodies prepared in (1); wherein, V₀-M₂The glass ceramic cured body prepared in comparative example 1, V_0.6-M₂Glass ceramic cured body prepared as representative of example 1, V_1.2-M₂Glass ceramic cured body prepared as representative example 2, V_1.8-M₂Glass ceramic cured body prepared in representative example 3, V_3.0-M₂Glass ceramic cured body prepared according to representative example 4, V_4.2-M₂Glass-ceramic prepared as representative of example 5Curing the body; as can be seen from FIG. 4, the series of samples have similar DSC curves, and all have an endothermic peak (about 540-600 ℃) and an exothermic peak, which correspond to the glass transition temperature (Tg) and the glass crystallization temperature, respectively. According to the document "Guerette M, Huang L.in-site Raman and Bright light scattering study of the international sample glass in response to temperature and pressure [ J]In a study of the Journal of Non-Crystalline Solids,2015,411: 101-. In FIG. 6 it can be observed that the glass transition temperature Tg of the samples varies with V₂O₅The amount of incorporation is increased and decreased. This shows that V₂O₅The incorporation of (b) has an effect on the structure of the glass network, the crystal structure of which becomes relatively less compact. A broad exothermic peak was also observed in the temperature range of 690 to 760 ℃. The exothermic peak corresponds to calcium molybdate (CaMoO)₄) The crystallization of (4).

FIG. 7 shows examples 6 to 7 (M)₂-V₃Series) of the XRD patterns of the glass-ceramic solidified bodies prepared in the above; FIG. 8 shows examples 6 to 7 (M)₂-V₃Series) of the glass-ceramic cured bodies prepared in the above step; from the XRD pattern (fig. 7), no crystalline phase peaks were formed except for the characteristic steamed bun peaks of the glass phase. From the Raman spectrum (FIG. 8), it can also be seen that only tetrahedra [ MoO ] exist with the glass phase₄]^2-Tensile and flexural vibration bands of ionic Mo-O, absent from CaMoO₄The crystalline phase is associated with a vibration band. XRD and Raman spectroscopy results correspond to each other and illustrate V₂O₅To MoO₃Solubility in boroaluminosilicate does have a beneficial effect.

Furthermore, the peaks associated with the Mo-O tensile vibrations are shifted, indicating that with MoO₃Increased amount of tetrahedra [ MoO ] in the glass phase₄]^2-The local environment of the ions is changed. Consideration of [ MoO ]₄]^2-The charge compensation mechanism of the ions may form a Mo-O-Mo structure.

From the above pair V_x-M₂And My-V3 series, such as XRD, Raman, SEM and DSC, etc., it is clear that V is known₂O₅MoO in para-boron aluminosilicate glass₃Does have a beneficial effect.

For examples 1-5 and comparative example 1 (V)_x-M₂Series) a PCT test was performed at 90 ℃ (± 2 ℃) to characterize the chemical stability of the glass-ceramic. As shown in FIGS. 9-12 for V respectively_x-M₂The leaching rates of Si, Ca, Mo and V elements of the sample are normalized within 28 days. Wherein, V₀-M₂The glass ceramic cured body prepared in comparative example 1, V_0.6-M₂Glass ceramic cured body prepared as representative of example 1, V_1.2-M₂Glass ceramic cured body prepared as representative example 2, V_1.8-M₂Glass ceramic cured body prepared in representative example 3, V_3.0-M₂Glass ceramic cured body prepared according to representative example 4, V_4.2-M₂Represents the glass-ceramic cured body prepared in example 5; in fig. 9, it can be observed that LRSi (fig. 9), LRCa (fig. 10), LRMo (fig. 11) and LRV (fig. 12) gradually decreased with increasing leaching time and remained almost unchanged after 14 days. After 28 days, the measured elements had LRSi, LRCa, LRMo and LRV of about 6.5X 10, respectively^-6g.m^-2.d^-1,3.6×10^-6g.m^-2.d^-1, 4×10^-6g.m^-2.d^-1And 4.3X 10^-6g.m^-2.d^-1. The normalized leaching rates for these elements were kept very low, indicating that V was added to some extent to the boroaluminosilicate glass formulations used in this study₂O₅Has little influence on the chemical stability of the glass.

Contact V_x-M₂The Raman characteristic spectra of the series of glass-ceramics suggest that V-O-Mo and Mo-O-Mo structures may be formed. I.e. V⁵⁺Ions enter the non-oxygen bridging zone of the glass, and the depolymerization zone of the glass is strengthened to a certain extent. For this reason, there may be a certain advantage in chemical stability of the cured body, i.e., the cured body is resistant to the LRSi, LRCa, LRMo and LRV as can be seenThe leaching performance tends to be better to a certain extent.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims

1. Adding V₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body is characterized in that the glass ceramic solidified body comprises the following components in percentage by mole:

40～60mol％SiO₂、10～15mol％B₂O₃、8～13mol％Na₂O、1.5～3.5mol％Al₂O₃、0.1～0.2mol％Gd₂O₃、8～13mol％CaO、1～3mol％MoO₃、0.6～4.2mol％V₂O₅；

the addition of V₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body comprises the following steps:

step one, the mol percentage of the raw materials is SiO₂、H₃BO₃、Na₂CO₃、CaCO₃、Al₂O₃、Gd₂O₃、MoO₃、NH₄VO₃Weighing the raw materials, uniformly mixing the raw materials by adopting a ball milling method, and carrying out ball milling for 20-25 min; wherein, MoO is used₃Simulating radioactive waste containing molybdenum;

step two, adopting a secondary melting heat treatment method, preparing a glass ceramic solidified body in a high-temperature box type furnace by using the raw materials of the corundum crucible after ball milling, wherein the melting procedure of the preparation is as follows: heating to 400-600 ℃ at a speed of 5-10 ℃/min, carrying out heat preservation calcination for 30-45 min, heating to 850-900 ℃ at a speed of 3-5 ℃/min, carrying out heat preservation calcination for 60-90 min, heating to 1000-1100 ℃ at a speed of 1-2 ℃/min, carrying out heat preservation melting for 30-45 min, continuously heating to 1250-1300 ℃ at a speed of 1-2 ℃/min, carrying out heat preservation melting for 60-120 min, carrying out quenching casting on a steel plate to obtain a glass frit, crushing the glass frit, sieving by a 200-mesh sieve, heating to 1250-1300 ℃ at a speed of 5-10 ℃/min, carrying out secondary melting for 1-3 h, and finally pouring to obtain a glass ceramic solidified body;

the process of uniformly mixing the raw materials by the ball milling method comprises the following steps: adding the raw materials and the process control agent into a ball milling tank, adding ball milling balls, placing on a planetary ball mill, performing wet ball milling mixing, and then drying to obtain uniformly mixed raw materials; the ball-milling ball adopts ceramic balls, the diameter of a big ball is about 6mm, the diameter of a small ball is about 3mm, and the mass ratio of the big ball to the small ball is 1: 2, the ball material ratio, namely the weight ratio of the ball grinding balls to the raw materials is 10: 1, ball milling at a rotating speed of 100-120 r/min; the process control agent is one or a mixture of more than two of absolute ethyl alcohol, imidazoline, normal hexane and stearic acid, and the adding volume accounts for 20-30% of the volume of the ball milling tank.

2. An additive V as claimed in claim 1₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body is characterized in that the glass ceramic solidified body comprises the following components in percentage by mole:

58.68mol％SiO₂、13.84mol％B₂O₃、11.26mol％Na₂O、2.85mol％Al₂O₃、0.15mol％Gd₂O₃、11.22mol％CaO、2mol％MoO₃、xmol％V₂O₅；

wherein, when xmol% V₂O₅When the value of x is 0.6-4.2, 58.68 mol% SiO₂、13.84mol％B₂O₃、11.26mol％Na₂O、2.85mol％Al₂O₃、0.15mol％Gd₂O₃11.22 mol% CaO and 2 mol% MoO₃The mole percentage of (b) is taken as a value by an integral sacrificial method, namely 1-x% of the original mole percentage is taken.

3. A method as in claimAddition of V as described in claim 1₂O₅The method for improving the solubility of molybdenum oxide in the glass ceramic solidified body is characterized in that the glass ceramic solidified body comprises the following components in percentage by mole:

wherein when ymol% MoO₃When the value of y is 2.0-2.5, 58.09 mol% SiO₂、13.70mol％B₂O₃、11.14mol％Na₂O、2.82mol％Al₂O₃、0.15mol％Gd₂O₃11.1 mol% CaO and 3 mol% V₂O₅The mole percentage of (b) is taken as a value by an integral sacrificial method, namely 1-y% of the original mole percentage is taken.