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CN-122010549-A - Rare earth-based perovskite ceramic solidified body with high entropy ferrite, and preparation method and application thereof

CN122010549ACN 122010549 ACN122010549 ACN 122010549ACN-122010549-A

Abstract

The invention belongs to the technical field of high-radioactivity waste treatment, and relates to a high-entropy rare-earth-based perovskite ceramic solidified body, a preparation method and application thereof, wherein the general formula of the solidified body is A 1/n (Fe x B y )O 3 , n represents the number of element types of a lattice site of the high-entropy A 1/n (Fe x B y )O 3 rare-earth-based perovskite ceramic solidified body A, n is an integer and is not less than 3 and not more than 7, the element types of A comprise Bi, sc, la, ce, pr, nd, pm, sm, eu, gd, tb, dy, Y, ho, er, tm, yb and Lu, the element B is at least three of transition metal elements Cr, mn, co, ni, al, ti, zr, hf, nb, ta, ce, x=0.01-1.00, and x=0-0.99. The method introduces the high-entropy strategy into the rare earth ferrite perovskite ceramic solidified body, and the ceramic solidified body not only can solidify a plurality of key high radionuclides, but also has excellent chemical stability, low leaching rate and low preparation temperature, and effectively avoids the disadvantages of strong selectivity and single selectivity of the ceramic solidified nuclides. The excellent performance of the ceramic solidified body enables the ceramic solidified body to have great application potential in the field of solidification treatment of high-radioactivity nuclear waste in spent fuel post-treatment factories.

Inventors

  • WANG XIAOWEN
  • LIU ZHENGHAO
  • Li Tengrui
  • ZHANG BO
  • CUI CAN
  • GAO GE
  • ZOU HAO
  • CHANG SHENG
  • LI GANGJIAN

Assignees

  • 西南科技大学
  • 内蒙古国创稀冶科技有限公司

Dates

Publication Date
20260512
Application Date
20260309

Claims (10)

  1. 1. The high-entropy rare earth ferrite-based perovskite ceramic solidified body is characterized by having a chemical general formula of A 1/n (Fe x B y )O 3 , wherein n represents the number of element types of lattice positions A of the high-entropy A 1/n (Fe x B y )O 3 rare earth ferrite-based perovskite ceramic solidified body, n is an integer, n is not less than 3 and not more than 7;A element types comprise at least three of Bi, sc, la, ce, pr, nd, pm, sm, eu, gd, tb, dy, Y, ho, er, tm, yb, lu, B element is at least three of transition metal elements Cr, mn, co, ni, al, ti, zr, hf, nb, ta, ce, x=0.01-1.00, and y=0-0.99.
  2. 2. A method for preparing the cured body of the rare earth ferrate-based perovskite ceramic of claim 1, comprising the steps of: (1) Mixing and dissolving the source A, the source Fe and the source B in deionized water, stirring, and adding a chelating agent; (2) Transferring the solution obtained in the step (1) into a stainless steel autoclave, sealing and carrying out hydrothermal reaction, naturally cooling the autoclave to room temperature, centrifugally separating brown precipitate, washing with deionized water and ethanol, and drying; (3) Performing heat treatment on the precipitate obtained in the step (2) in a muffle furnace, and grinding and sieving the precipitate in an agate mortar to obtain A 1/n (Fe x B y )O 3 powder; (4) Ball milling the powder A 1/n (Fe x B y )O 3 obtained in the step (3) for later use; (5) Pressing the grinding A 1/n (Fe x B y )O 3 powder obtained in the step (4) into a wafer, and placing the wafer in a muffle furnace for sintering treatment; (6) Repeating the steps (4) and (5) for 1-5 times to obtain the rare earth ferrate-based perovskite ceramic solidified body A 1/n (Fe x B y )O 3 .
  3. 3. The method for preparing a cured body of the rare earth ferrate-based perovskite ceramic of claim 2, wherein the source A is at least one of an oxide, a nitrate, a chloride, a carbonate and an acetate, the source Fe is at least one of Fe powder, an Fe oxide, a nitrate, a chloride, a carbonate and an acetate, and the source B is at least one of an oxide, a nitrate, a chloride, a carbonate and an acetate.
  4. 4. The method for producing a cured body of a rare earth ferrate-based perovskite ceramic according to claim 2 or 3, wherein the ratio of the amount of the A source to the sum of the Fe source and the B source is 0.4 to 1:1.
  5. 5. The method for preparing a cured body of the rare earth ferrate-based perovskite ceramic according to claim 2, wherein the chelating agent is one or a combination of more of citric acid, oxalic acid, tannic acid, glycyrrhizic acid, caffeic acid and tartaric acid, and the ratio of the chelating agent to the total mass of the source A, the source Fe and the source B is 1-20:1.
  6. 6. The method for producing a cured body of a rare earth ferrate-based perovskite ceramic according to claim 2, wherein in the step (2), the temperature of the hydrothermal reaction is 100 o C~180 o C and the reaction time is 1 to 48 hours.
  7. 7. The method for preparing a cured body of a rare earth ferrate-based perovskite ceramic according to claim 2, wherein the heat treatment in the step (3) is to keep the temperature at 300 o C~1200 o C for 1-48 hours.
  8. 8. The method for preparing a cured body of a rare earth ferrate-based perovskite ceramic according to claim 2, wherein in the step (4), the ball milling operation is as follows: Adding the powder A 1/n (Fe x B y )O 3 obtained in the step (3) into a ball mill, and grinding at a grinding speed of 100 rpm-2000 rpm and a grinding time of 0.2-12 h according to a ball mass ratio of 1:1-200:1.
  9. 9. The method for producing a cured body of a rare earth ferrate-based perovskite ceramic according to claim 2, wherein in the step (5), the sintering treatment is performed by heating to 300-700 o C at 10 o C/min, heating to 800-1400 o C at 5 o C/min, and maintaining the temperature for 0.5-48 h.
  10. 10. The use of the cured body of a rare earth ferrate-based perovskite ceramic according to claim 1 or the cured body of a rare earth ferrate-based perovskite ceramic prepared by the method according to claim 2 in the field of curing treatment of highly radioactive nuclear waste.

Description

Rare earth-based perovskite ceramic solidified body with high entropy ferrite, and preparation method and application thereof Technical Field The invention belongs to the technical field of high-radioactivity waste treatment, and relates to a rare earth-based perovskite ceramic solidified body of ferrate, a preparation method and application thereof. Background Along with the continuous accumulation of a large amount of spent fuel containing uranium, plutonium and fission products generated in the nuclear power operation process, for the safety of the spent fuel of the nuclear power plant and the improvement of the resource utilization rate, a closed type nuclear fuel circulation policy is adopted in China, so that the disposal of high-level waste containing actinides generated by post-treatment of the spent fuel becomes an important link of the safety of the spent fuel. The high level waste (HLLW) containing actinides has the characteristics of high radiation level, strong radiation effect, complex components, strong corrosiveness and the like, has great threat to the whole biosphere, especially the human living environment, and seriously affects the sustainable development of nuclear energy. For high-radioactivity waste, mainly there are glass solidification and artificial rock ceramic solidification with great development potential, wherein the technology of glass solidification high-radioactivity waste liquid is relatively mature, and the technology is applied in engineering, but as glass solidification belongs to thermodynamically metastable phase, amorphous substance is easy to be influenced by water or water vapor, the stability of the reticular structure of the glass is weakened, the integrity of the material is damaged, and the long-term storage safety is influenced. The solidification of the artificial rock can almost fix all nuclides contained in the high-level waste in the crystal phase, and the artificial rock has the advantages of easy processing, high mechanical strength, high chemical stability and good leaching resistance, and is considered to be a solidification form which is ideal for treating the high-level waste liquid. The curing of artificial rock ceramic is based on the homography, and the radionuclide is mixed with the curing base material, and then sintered to prepare a ceramic curing body, and the radionuclide is fixed at the lattice position of the ceramic phase. The ceramic curing is in a research stage at present and is not practically applied, and the ceramic curing has the advantages of excellent physical property and chemical property, high safety coefficient and long-term treatment engineering application prospect. However, the method has the defects of strong selectivity of the curing nuclide, single curing nuclide and complex process flow. Lanthanum ferrite (LaFeO 3, LFO) is used as a ceramic material with an ABO 3 perovskite structure, is widely applied to the fields of sensors, catalysts, batteries and the like in the past research by virtue of the characteristics of high stability, composition, structural flexibility and the like, and has great potential as a ceramic curing substrate by comparing the characteristics of HLLW mentioned in the previous paragraph with the requirement of high-level waste curing high stability. For homogeneous ceramic solidification matrices, the single component perovskite structure is selective for nuclides, which is difficult for multi-element complex high level waste treatment. Therefore, a new system needs to be developed to deal with this problem. In recent years, high entropy is a new strategy for regulating and controlling material properties. The method has theoretical advantages in the preparation of the high level waste solidification product, and the Gibbs free energy is reduced along with the increase of the entropy value, so that the formation of single-phase solid solution is promoted, and the preparation temperature is reduced. In contrast to conventional one-component ceramic cured substrates having selective curing of nuclides, the high entropy ceramic is occupied by five or more elements at lattice sites, thus allowing the addition of multiple curing elements from high strength materials. The high-entropy ceramic not only can simultaneously solidify a plurality of different radionuclides, but also has excellent chemical stability (Ceramics International, 2024, (50) 4:5955-5961), but has little research on irradiation resistance and mechanical properties. Disclosure of Invention In view of the above, the invention provides a high-entropy strategy aiming at the existing ceramic solidified body, which has strong selectivity of solidified nuclide, single and complex process flow, and develops the high-entropy rare-earth-ferrite-based perovskite ceramic solidified body with excellent solidifying performance. It should be noted that, similar to the high-entropy alloy, the unit cell of the high-entropy ceramic material contains a