A method for synchronously solidifying rare earth waste residue multi-nuclides with a glass-ceramic solid body

Abstract

The present invention provides a method for simultaneously solidifying multiple nuclides in rare earth waste slag in a glass-ceramic solid body. The method comprises: mixing rare earth molten salt electrolytic slag with mineral slag to obtain a base batch material; melting the base batch material at high temperature to obtain a base glass; and crystallizing the base glass to obtain a glass-ceramic solid body. The R2O-CaO-SiO2-X glass-ceramic solid body achieves simultaneous solidification of multiple nuclides and is capable of stable solidification. Testing using the ASTM C1285-2014 standard PCT powder method revealed that the cerium and neodymium leaching rates were 1.22×10 ‑6 g·m ‑2 ·d ‑1 With 1.20×10 ‑6 g·m ‑2 ·d ‑1 , far below the national standard limit, and at the excellent level specified by the standard. It can be used to solidify radioactive nuclides in rare earth waste and solve the problem of radioactive contamination.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmentally friendly treatment of radioactive waste, and relates to a method for synchronously solidifying multiple nuclides of rare earth waste residue with a glass-ceramic solid body, thereby realizing synchronous and stable solidification of multiple radioactive nuclides. Background Art

[0002] Rare earth minerals are important mineral resources. The rare earth elements they contain possess unique physical and chemical properties, making them crucial in cutting-edge fields such as batteries and catalysts. However, rare earth minerals are often associated with radioactive nuclides, such as thorium, radium, and uranium, at levels exceeding natural background levels. During the mining and smelting process, one ton of rare earth ore produces approximately 1.5 tons of waste residue containing radioactive rare earth elements. Rare earth tailings are similar to uranium tailings, but while uranium has already been extracted from uranium tailings, rare earth tailings are enriched with radioactive nuclides, posing a greater risk. For example, the radioactive thorium contained in rare earth tailings can cause lung cancer after long-term exposure. Furthermore, most rare earth mines are open-pit mined, requiring mining waste to be stored in open-air piles or buried in pits. Leaching these wastes through prolonged rainfall can easily leach radioactive nuclides into groundwater and surface water, causing significant radioactive contamination in the surrounding environment and posing a serious health risk to workers and the public. Therefore, how to properly deal with rare earth tailings has become an urgent problem to be solved.

[0003] At present, the main treatment methods for radioactive rare earth tailings are glass solidification, cement solidification and ceramic solidification. However, these methods all have the disadvantages of easy dissolution of nuclides and poor solidification effect. The problem with glass solidification is that it has poor acid and alkali resistance. In acidic or alkaline environments, nuclides are easily dissolved. In addition, glass is metastable and tends to crystallize under high temperature and high pressure. Crystallization will cause the structure of the glass to change, resulting in easy secondary dissolution of nuclides. Cement solidification and ceramic solidification also face the problem of poor chemical corrosion resistance. They cannot withstand long-term chemical corrosion. Eventually, as the structure of cement and ceramics is destroyed, nuclides are dissolved secondary. Microcrystalline glass combines the advantages of both ceramic and glass materials, and has good strength, chemical stability and tolerance to nuclides. It has been widely used in the field of radioactive waste treatment.

[0004] CN103979794A discloses a method for preparing glass-ceramics from heavy metal gypsum. The method uses heavy metal-containing waste gypsum as raw material, undergoes low-temperature assisted decomposition of the waste glass to obtain a pre-sintered glass-ceramic containing a calcium-silicon source. Other glass-ceramic element sources and a nucleator are then added. The glass-ceramics are then obtained through a series of steps, including blending, melting and stirring, water quenching and grinding, secondary melting and heat preservation, nucleation, and crystallization. The preparation process is complex and unsuitable for large-scale industrial production.

[0005] CN112142333A discloses a multi-source fluorine-containing waste residue microcrystalline glass solidification body and its preparation method and use. The fluorine-containing waste residue is mixed with auxiliary materials and then melted, and then formed, annealed, and crystallized in sequence to obtain the microcrystalline glass solidification body.

[0006] CN112382429A discloses a method for collaborative glass solidification of medium- and low-level radioactive glass fibers and combustible solid nuclear waste incineration ash. Specifically, it provides a method for collaborative glass solidification treatment using medium- and low-level radioactive glass fibers and combustible solid waste incineration ash such as cotton cloth, plastic, rubber, and absorbent paper. This method is only applicable to combustible waste incineration ash, has great limitations, and the radionuclide dissolution rate is unknown and has no quantitative evaluation.

[0007] CN104318971A discloses a glass matrix composition for low- to medium-level radioactive glass fibers. The glass matrix composition is melted with radioactive glass fiber waste to form a solidified body. This method is also only applicable to radioactive glass fiber waste. However, the glass fiber itself can be used in the field of building materials, and it is wasteful to treat it only as waste.

[0008] However, the field of glass-ceramics solidification also has the following problems: rare earth waste contains a variety of radioactive nuclides with different valence states, and the current glass-ceramics solidification system can only solidify a certain valence state, or the solidification stability or efficiency is insufficient, which makes it difficult to meet the existing solidification needs. In addition, simulating the above-mentioned radioactive nuclides through rare earth elements is also a common research method. In summary, this field urgently needs a method for the simultaneous and stable solidification of multiple radioactive nuclides through glass-ceramics to provide theoretical and technical support for the harmless treatment of radioactive rare earth waste. Summary of the Invention

[0009] The object of the present invention is to provide a method for synchronously solidifying rare earth waste residue multi-nuclides by using a glass-ceramic solid body.

[0010] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0011] The present invention provides a method for synchronously solidifying rare earth waste residue multi-nuclides in a glass-ceramic solid body, the method comprising:

[0012] The ingredients of the solidified body are mixed to obtain a basic batch material, the basic batch material is melted at a high temperature to obtain a basic glass, and the basic glass is crystallized to obtain a microcrystalline glass solidified body.

[0013] The ingredients of the solidified body include rare earth molten salt electrolytic slag, silicon slag and auxiliary materials.

[0014] The present invention mixes rare earth molten salt electrolytic slag with slag mineral raw materials to obtain a basic batch material, forms R2O-CaO-SiO2-X basic glass by a high-temperature melting method, and then crystallizes the basic glass to form a microcrystalline glass solid body that nucleates and grows by a "new phase separation" method. By pre-loading radioactive nuclides through the "phase separation" mechanism of the amorphous structure, the reflective nuclides are promoted to enter the crystal, which can maximize the solidification of radioactive nuclides and achieve synchronous and stable solidification of multiple nuclides. The present invention can solidify multiple nuclides, and the dissolution rates of Ce and Nd in the R2O-CaO-SiO2-X microcrystalline glass solid body are extremely low, achieving synchronous and stable solidification of multiple nuclides. The glass solid body in the present invention can be used simultaneously to simulate radioactive nuclides Ce and Nd.

[0015] As a preferred technical solution of the present invention, the rare earth lava electrolytic slag includes neodymium oxide and cerium oxide.

[0016] In the present invention, the cerium and neodymium elements in the glass solidification body will replace the calcium element in the generated crystal and form new chemical bonds in situ to form crystal structures such as lanceolite and oxyapatite that solidify Ce and Nd, thereby achieving the simultaneous solidification of multiple rare earth elements.

[0017] Preferably, the components of the rare earth molten salt electrolytic slag include, by mass fraction, 40.0-70.0% Nd2O3, 10.0-30.0% Pr2O3, 5.0-15.0% CaF2 and 3.0-10.0% Fe2O3, wherein the mass fraction of Nd2O3 can be 40.0%, 45.0%, 50.0%, 55.0%, 60.0%, 65.0% or 70.0%, etc., the mass fraction of Pr2O3 can be 10.0%, 15.0%, 20.0%, 25.0% or 30.0%, etc., the mass fraction of CaF2 can be 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10.0%, 11.0%, 12.0%, 13.0%, 14.0% or 15.0%, etc., and the mass fraction of Fe2O3 can be 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0% or 10.0%, etc., but are not limited to the listed values, and other values ​​not listed within the above numerical ranges are equally applicable.

[0018] Preferably, the mass fraction of the rare earth molten salt electrolytic slag in the ingredients is 5.0-20.0%, where the mass fraction can be 5.0%, 10.0%, 15.0% or 20.0%, etc., but is not limited to the listed values. Other unlisted values ​​within this numerical range are also applicable.

[0019] As a preferred technical solution of the present invention, the components of the silicon slag include, by mass fraction, 50.0-90.0% SiO2 and 10.0-30.0% Na2O, wherein the mass fraction of the SiO2 can be 50.0%, 60.0%, 70.0%, 80.0% or 90.0%, etc., and the mass fraction of the Na2O can be 10.0%, 20.0% or 30.0%, etc., but are not limited to the listed values. Other values ​​not listed within the above numerical ranges are also applicable.

[0020] Preferably, the mass fraction of the silicon slag in the ingredients is 30.0-60.0%, wherein the mass fraction can be 30.0%, 35.0%, 40.0%, 45.0%, 50.0%, 55.0% or 60.0%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0021] As a preferred technical solution of the present invention, the auxiliary materials include CeO2, alumina powder, boric acid, limestone, fluorite and iron oxide.

[0022] Preferably, the mass fraction of the auxiliary materials in the ingredients is 20.0-50.0%, wherein the mass fraction can be 20.0%, 30.0%, 40.0% or 50.0%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, based on the mass of the auxiliary material as 100%, the mass fraction of CeO2 is 4.0-10.0%, wherein the mass fraction can be 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0% or 10.0%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, based on the mass of the auxiliary material as 100%, the mass fraction of the fluorite is 4.0-10.0%, wherein the mass fraction can be 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0% or 10.0%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, based on the mass of the excipient as 100%, the mass fraction of the boric acid is 1.0-10.0%, wherein the mass fraction can be 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0% or 10.0%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, based on the mass of the auxiliary material being 100%, the mass fraction of the iron oxide is 2.0-5.0%, wherein the mass fraction can be 2.0%, 3.0%, 4.0% or 5.0%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, based on the mass of the auxiliary material being 100%, the mass fraction of the alumina powder is 1.0-5.0%, wherein the mass fraction can be 1.0%, 2.0%, 3.0%, 4.0% or 5.0%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0028] Preferably, based on the mass of the auxiliary material as 100%, the mass fraction of the limestone is 5.0-15.0%, wherein the mass fraction can be 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10.0%, 11.0%, 12.0%, 13.0%, 14.0% or 15.0%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0029] As a preferred technical solution of the present invention, the mixing includes grinding mixing.

[0030] As a preferred technical solution of the present invention, the high-temperature melting includes keeping the basic batch material warm to obtain a glass melt, and cooling and molding the glass melt to obtain the basic glass.

[0031] In the present invention, the glass melt is poured onto a steel plate and cooled to obtain the basic glass.

[0032] As a preferred technical solution of the present invention, the heat preservation is carried out in a crucible.

[0033] Preferably, the insulation temperature is 1400-1500°C, wherein the temperature can be 1400°C, 1410°C, 1420°C, 1430°C, 1440°C, 1450°C, 1460°C, 1470°C, 1480°C, 1490°C or 1500°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In the present invention, if the insulation temperature is too high, the volatile components in the ingredients will volatilize excessively, affecting product performance, while if it is too low, the ingredients will not be fully melted.

[0035] Preferably, the insulation time is 30 to 60 minutes, wherein the time can be 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes or 60 minutes, etc., but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0036] In the present invention, if the holding time is too long, the volatile components in the ingredients will volatilize excessively, affecting product performance, while if the holding time is too short, the ingredients will not be fully melted.

[0037] As a preferred technical solution of the present invention, the crystallization treatment includes a first stage high temperature treatment and a second stage high temperature treatment performed sequentially.

[0038] Preferably, the heating rate of the high temperature treatment is 5 to 15°C / min, wherein the heating rate can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min or 15°C / min, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0039] Preferably, the temperature of the high-temperature treatment stage is 550-650°C, wherein the temperature can be 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C or 650°C, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0040] Preferably, the holding time of the high-temperature treatment is 30 to 90 minutes, wherein the time can be 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes or 90 minutes, etc., but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0041] Preferably, the temperature of the second-stage high-temperature treatment is 800-830°C, wherein the temperature can be 800°C, 805°C, 810°C, 815°C, 820°C, 825°C or 830°C, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0042] Preferably, the holding time of the second-stage high-temperature treatment is 90 to 150 minutes, wherein the time can be 90 minutes, 100 minutes, 110 minutes, 120 minutes, 130 minutes, 140 minutes or 150 minutes, etc., but is not limited to the listed values. Other unlisted values ​​within this numerical range are also applicable.

[0043] As a preferred technical solution of the present invention, the preparation method comprises:

[0044] Mixing rare earth molten salt electrolytic slag with mineral slag to obtain a basic batch material, melting the basic batch material at a high temperature to obtain a basic glass, and crystallizing the basic glass to obtain a glass-ceramic solid body;

[0045] The high-temperature melting includes heat preservation, the heat preservation temperature is 1400-1500°C, and the time is 30-60 minutes;

[0046] The crystallization treatment includes a first-stage high-temperature treatment and a second-stage high-temperature treatment. The heating rate of the first-stage high-temperature treatment is 5-15°C / min, the temperature of the first-stage high-temperature treatment is 550-650°C, the holding time of the first-stage high-temperature treatment is 30-90 minutes, the temperature of the second-stage high-temperature treatment is 800-830°C, and the holding time of the second-stage high-temperature treatment is 90-150 minutes.

[0047] As a preferred technical solution of the present invention, the method of synchronously solidifying multiple nuclides of rare earth waste residue with a microcrystalline glass solidification body is used to simulate radioactive nuclides Ce and Nd to achieve synchronous solidification of multiple nuclides.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The present invention solidifies the simulated radioactive nuclides through strong chemical bonding, which has higher solidification stability.

[0050] (2) The nuclides in the microcrystalline glass solidified body prepared by the present invention are not easily dissolved and have excellent anti-leaching performance. Compared with the traditional cement solidification method, it has higher disposal safety.

[0051] (3) The present invention utilizes a novel phase-separated growth method to pre-load the radioactive nuclide in the crystal phase, maximizing its solidification within the crystal and achieving higher solidification efficiency. Compared to the lanceolite crystals formed by phase-separated nucleation and heterogeneous nucleation, the Ce content in the crystals increased by 42.97% and the Nd content by 31.93%.

[0052] (4) The solidified body prepared by the solidification method of the present invention has excellent anti-leaching performance. The leaching rates of neodymium and cerium in a deionized water solution at 90°C for 7 days are 1.22×10 -6 gm -2 ·d -1 With 1.20×10 -6 g·m -2 ·d -1 , an order of magnitude lower than the solidified body in the Pacific Northwest Laboratory in the United States.

[0053] (5) The microcrystalline glass solidified body prepared by the present invention can simultaneously solidify multiple radioactive nuclides through a new phase-separated growth method, which has more practical application prospects compared to the current glass that can only solidify a single nuclide. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a flow chart for preparing the solidified glass-ceramics of Examples 1-4 of the present invention.

[0055] Figure 2 These are photos of the base glasses prepared in Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0056] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0057] Example 1

[0058] This embodiment produces a glass-ceramic solid body, wherein the preparation method is as follows Figure 1 The flow chart shows:

[0059] Take 7.0g of fluorite, 35.0g of silicon slag, 20.0g of silica, 6.0g of rare earth molten salt electrolytic slag containing neodymium, 4.0g of cerium oxide, 1g of aluminum oxide powder, and add other raw materials to prepare 100g of basic glass frit; the composition of the other raw materials is: 6.0g of potassium carbonate, 6.0g of boric acid, 11.0g of limestone, 4.0g of iron oxide, and 4.0g of CeO2;

[0060] The glass material is melted at 1450°C for 45 minutes to form a glass melt, which is then cooled and formed to obtain a solidified base glass simulating radioactive nuclides;

[0061] The resulting base glass was heated from room temperature to 600°C at a rate of 10°C / min, where it separated and nucleated. The glass was then held at 600°C for 60 minutes. The temperature was then raised from 600°C to 815°C at a rate of 10°C / min, where it was held at 815°C for 120 minutes. The glass crystallized to form a crystalline phase capable of solidifying the simulated radioactive nuclide, resulting in a solidified glass-ceramic, achieving the solidification of cerium and neodymium.

[0062] The obtained microcrystalline glass solidified body was ground and passed through a 200-mesh sieve. The PCT powder method test was carried out according to ASTM C1285-2014. The leaching rates of cerium and neodymium were 1.22×10 -6 g·m -2 ·d -1 With 1.20×10 -6 g·m -2 ·d -1, the curing effect is excellent. The stable curing of cerium and neodymium is achieved.

[0063] Example 2

[0064] This embodiment produces a glass-ceramic solid body, wherein the preparation method is as follows Figure 1 The flow chart shows:

[0065] Take 7.0g of fluorite, 35.0g of silicon slag, 20.0g of silica, 6.0g of rare earth molten salt electrolytic slag containing neodymium, 4.0g of cerium oxide, 3g of aluminum oxide powder, and add other raw materials to prepare 100g of basic glass frit; the composition of the other raw materials is: 6.0g of potassium carbonate, 6.0g of boric acid, 11.0g of limestone, 4.0g of iron oxide, and 4.0g of CeO2;

[0066] The glass material is melted at 1400°C for 60 minutes to form a glass melt, which is then cooled and formed into a solidified base glass simulating radioactive nuclides.

[0067] The resulting base glass was heated from room temperature to 600°C at a rate of 10°C / min, where it separated and nucleated. The glass was then held at 600°C for 60 minutes. The temperature was then raised from 600°C to 815°C at a rate of 10°C / min, where it was held at 815°C for 120 minutes. The glass crystallized to form a crystalline phase capable of solidifying the simulated radioactive nuclide, resulting in a solidified glass-ceramic, achieving the solidification of cerium and neodymium.

[0068] The obtained microcrystalline glass solid body was ground and passed through a 200-mesh sieve. The PCT powder method test was performed according to ASTM C1285-2014. The leaching rates of cerium and neodymium were 2.50×10 -6 g·m -2 ·d -1 With 2.20×10 -6 g·m -2 ·d -1 , the curing effect is excellent. The stable curing of cerium and neodymium is achieved.

[0069] Example 3

[0070] This embodiment produces a glass-ceramic solid body, wherein the preparation method is as follows Figure 1 The flow chart shows:

[0071] Take 6.0g of fluorite, 35.0g of silicon slag, 20.0g of silica, 6.0g of rare earth molten salt electrolytic slag containing neodymium, 4.0g of cerium oxide, 3g of aluminum oxide powder, and add other raw materials to prepare 100g of basic glass frit; the composition of the other raw materials is: 6.0g of potassium carbonate, 6.0g of boric acid, 11.0g of limestone, 4.0g of iron oxide, and 4.0g of CeO2;

[0072] The glass material is melted at 1500°C for 30 minutes to form a glass melt, which is then cooled and formed into a solidified base glass simulating radioactive nuclides.

[0073] The resulting base glass was heated from room temperature to 600°C at a rate of 10°C / min, where it separated and nucleated. The glass was then held at 600°C for 60 minutes. The temperature was then raised from 600°C to 815°C at a rate of 10°C / min, where it was held at 815°C for 120 minutes. The glass crystallized to form a crystalline phase capable of solidifying the simulated radioactive nuclide, resulting in a solidified glass-ceramic, achieving the solidification of cerium and neodymium.

[0074] The obtained microcrystalline glass solid body was ground and passed through a 200-mesh sieve. The PCT powder method test was performed according to ASTM C1285-2014. The leaching rates of cerium and neodymium were 4.90×10 -6 g·m -2 ·d -1 With 5.40×10 -6 g·m -2 ·d -1 , the curing effect is excellent. The stable curing of cerium and neodymium is achieved.

[0075] Example 4

[0076] This embodiment produces a surface-crystallized glass-ceramic solidified body, wherein the preparation method is as follows: Figure 1 The flow chart shows:

[0077] Take 5.0g of fluorite, 35.0g of silicon slag, 20.0g of silica, 6.0g of neodymium-containing rare earth molten salt electrolytic slag, 4.0g of cerium oxide, 3g of aluminum oxide powder, and add other raw materials to prepare 100g of basic glass frit; the composition of the other raw materials is: 6.0g of potassium carbonate, 6.0g of boric acid, 11.0g of limestone, 4.0g of iron oxide, and 4.0g of CeO2;

[0078] The glass material is melted at 1450°C for 45 minutes to form a glass melt, which is then cooled and formed to obtain a solidified base glass simulating radioactive nuclides;

[0079] The resulting base glass was heated from room temperature to 600°C at a rate of 10°C / min, where it separated and nucleated. The glass was then held at 600°C for 60 minutes. The temperature was then raised from 600°C to 815°C at a rate of 10°C / min, where it was held at 815°C for 120 minutes. The glass crystallized to form a crystalline phase capable of solidifying the simulated radioactive nuclide, resulting in a solidified glass-ceramic, achieving the solidification of cerium and neodymium.

[0080] The obtained microcrystalline glass solid body was ground and passed through a 200-mesh sieve. The PCT powder method test was performed according to ASTM C1285-2014. The leaching rates of cerium and neodymium were 7.10×10 -6 g·m -2 ·d -1 With 8.30×10 -6 g·m -2 ·d -1 , the curing effect is excellent. The stable curing of cerium and neodymium is achieved.

[0081] The photos of the basic glass prepared in Examples 1-4 of the present invention are as follows Figure 2 shown.

[0082] Comparative Example 1

[0083] In this comparative example, an oxyapatite glass-ceramic solid was prepared. The preparation method of the glass-ceramic solid is to mix Ca(NO3)2·4H2O and Nd(NO3)3·6H2O with anhydrous ethanol and glacial acetic acid in a beaker, stir until the solution is clear, add tetraethyl orthosilicate (TEOS) and stir and mix for 24 hours. The solution is dried at 80°C for 6 days and then heated at 200°C for 1 hour. The obtained powder product is placed in a crucible and calcined at 600°C. Then, the sample is calcined at 1000°C for 1 hour and cooled, with the heating and cooling rates both being 5°C / min. After cooling, the oxyapatite glass-ceramic solid is obtained.

[0084] The test results of the leaching rates of radioactive nuclides cerium and neodymium in Examples 1-4 and Comparative Example 1 are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] As can be seen from the table above, the glass-ceramics prepared in this invention can simultaneously solidify multiple radionuclides through a novel phase-separated growth process, offering more practical application prospects compared to previous glass methods that could only solidify a single radionuclide. Furthermore, when the glass-ceramics prepared in this invention were tested using the PCT powder method according to ASTM C1285-2014, the leaching rates of cerium and neodymium were an order of magnitude lower than those achieved by previous studies, demonstrating superior solidification performance.

[0089] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for simultaneously solidifying rare earth waste residue multi-element nuclides in a glass-ceramic solid body, characterized by: The method comprises: Mixing ingredients of the solidified body to obtain a basic batch material, melting the basic batch material at a high temperature to obtain a basic glass, and crystallizing the basic glass to obtain a glass-ceramic solidified body; The ingredients of the solidified body include rare earth molten salt electrolytic slag, silicon slag and auxiliary materials; The rare earth molten salt electrolytic slag includes neodymium oxide and cerium oxide; The mass fraction of the rare earth molten salt electrolytic slag in the ingredients is 5.0-20.0%; The mass fraction of the silicon slag in the ingredients is 30.0-60.0%; The auxiliary materials include CeO2, alumina powder, boric acid, limestone, fluorite and iron oxide; The mass fraction of the auxiliary materials in the ingredients is 20.0-50.0%; The high-temperature melting includes heat preservation, the heat preservation temperature is 1400-1500° C., and the heat preservation time is 30-60 minutes; The crystallization treatment includes a first high temperature treatment and a second high temperature treatment. The heating rate of the first high temperature treatment is 5-15°C / min, the temperature of the first high temperature treatment is 550-650°C, the holding time of the first high temperature treatment is 30-90min, and the temperature of the second high temperature treatment is 800-830°C, the holding time of the second high temperature treatment is 90-150min. The method is used to simulate radioactive nuclides Ce and Nd and realize the simultaneous solidification of multiple nuclides.

2. The method according to claim 1, characterized in that The components of the rare earth molten salt electrolytic slag include, by mass fraction, 40.0-70.0% Nd2O3, 10.0-30.0% Pr2O3, 5.0-15.0% CaF2 and 3.0-10.0% Fe2O3; the total mass fraction of the components of the rare earth molten salt electrolytic slag is 100%.

3. The method according to claim 1, characterized in that The components of the silicon slag include, by mass fraction, 50.0-90.0% SiO2 and 10.0-30.0% Na2O; the total mass fraction of the components of the silicon slag is 100%.

4. The method according to claim 1, wherein Taking the mass of the auxiliary material as 100%, the mass fraction of the CeO2 is 4.0-10.0%.

5. The method according to claim 1, wherein Based on the mass of the auxiliary material being 100%, the mass fraction of the fluorite is 4.0-10.0%.

6. The method according to claim 1, characterized in that Based on the mass of the auxiliary material being 100%, the mass fraction of the boric acid is 1.0-10.0%.

7. The method according to claim 1, characterized in that Based on the mass of the auxiliary material being 100%, the mass fraction of the iron oxide is 2.0-5.0%.

8. The method according to claim 1, characterized in that Based on the mass of the auxiliary material being 100%, the mass fraction of the alumina powder is 1.0-5.0%.

9. The method according to claim 1, characterized in that Based on the mass of the auxiliary material being 100%, the mass fraction of the limestone is 5.0-15.0%.

10. The method according to claim 1, characterized in that The mixing includes grinding mixing.

11. The method according to claim 1, wherein The high-temperature melting includes keeping the basic batch material warm to obtain a glass melt, and cooling and molding the glass melt to obtain the basic glass.

12. The method according to claim 1, characterized in that The heat preservation is carried out in a crucible.

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