JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2023
·Vol. 106
·期 10
·5723-5734
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IF 3.9
Yi Zhong,Yun Wang,Zhenliang Yang,Bingqing Li,Jingkun Xu,Zhiyi Wang,Liang Xie,Limei Duan,Fengyun Hu,Mingfu Chu,Rui Gao,Pengcheng Zhang,Bin Bai
In this work, the sintering kinetics of pure UO 2 and 0.5 wt.%MnO-doped UO 2 was studied by a high-temperature dilatometer heated up to 1500°C. In addition, the sintering behavior of pure UO 2 and 0.5 wt.%MnO-doped UO 2 was studied by pressureless sintering technique. The results showed that MnO doping enhanced the grain boundary diffusion of UO 2 , which can effectively decrease the densification temperature and promote grain growth. The sintering temperature of UO 2 was significantly reduced by about 200°C with the addition of 0.5 wt.%MnO. The microscopic morphology studies showed that there were still fine particles agglomerated, forming sintered spheres in the matrix even if no severe agglomeration and bimodal size distribution were observed in raw UO 2 powder. The microstructure evolution of the sintered sphere and UO 2 matrix during the densification process was studied by isothermal sintering. Finally, the present analyses indicated that the densification of UO 2 matrix can be accelerated by adding MnO or increasing the sintering temperature, thus improving the densification inhomogeneity of UO 2 matrix.
研究领域:
材料科学
·
核工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NUCLEAR MATERIALS
·
2020
·
IF 2.485
Yi-Chuan Liu,Ya-Lan Liu,Yuan Zhao,Zhe Liu,Tong Zhou,Qing Zou,Xian Zeng,Yu-Ke Zhong,Mei Li,Zhong-xuan Sun,Wei-Qun Shi
For UO 2 -based spent fuel , it is usually electrochemically reduced and then refined in molten salt with respect to the so-called pyrochemical reprocessing approach. In this work, we report a new method with the assistance of NH 4 Cl to directly achieve convenient separation of UO 2 over La 2 O 3 in Ar atmosphere which does not require an electrochemical process . According to the results from both powder and pellet samples, the separation is achieved by dissolving La 2 O 3 into the LiCl–KCl molten salt with NH 4 Cl, whilst UO 2 cannot be dissolved and remains in solid form. It was found that the dissolution kinetics of La 2 O 3 in the powder sample was fast and its removal efficiency in the mixture of La 2 O 3 and UO 2 was high, but a specific amount of UO 2 was also dissolved, which lead to a low recovery efficiency of UO 2 . In contrast, when the pellet samples after sintering at 1473 K were used, the recovery efficiency of UO 2 can be increased. Nevertheless, the dissolution kinetics of La 2 O 3 was correspondingly reduced, and more NH 4 Cl was required to complete the dissolution reaction . By improving and optimizing the experimental conditions, the UO 2 recovery efficiency of 92.0% can be achieved, while the removal efficiency of La 2 O 3 was 94.4%. More importantly, this novel separation method may be also useful for the separation of UO 2 over mixed lanthanide oxides.
研究领域:
核化学与化工
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2025
·
IF 1.6
Han Wei,Cui Ming,Liu Rugeng,Zhang Meng,Li Mei
The effects of different doping amounts of BaO on the structure and oxidation behavior of UO 2 were investigated by a series of methods. The results indicated that the solid solutions (U 1- y Ba y )O 2- y was formed after sintering. With the increase of y value, the lattice parameters of (U 1- y Ba y )O 2- y and oxygen vacancies increased, OOT and MRT gradually rose and O/(U + M) final decreased. The oxidation products were characterized by XRD, SEM and XPS. As y value increased, the average valence state of uranium decreased, the oxidation became incomplete and the average activation energy of (U 1- y Ba y )O 2- y increased from 89.50 to 125.15 kJ/mol. Graphical
BaO is dispersed in UO 2 matrix and formed oxygen vacancies. The delayed UO 2 oxidation is more obvious with more BaO doping. And the difference of U valence state is found from the oxidation products at 550 ℃.
研究领域:
材料科学
·
核工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Peng Wang,Jiawei Meng,Ning Li,Chuncheng Wei,Shuang Li,Xin Geng,Xiaowei Li,Jipeng Zhang,Guangwu Wen
We report a simple and general method for the production of UO 2 nanoparticles by heat-treating an aqueous mixture of uranyl acetate dihydrate and ethylenediamine. The products were characterized, and the effects of heat treatment temperature and time were investigated. When heat treatment time was fixed at 24 h, UO 2 could not be obtained at temperature lower than 160 °C, both UO 2 and ianthinite were obtained at 200 and 240 °C, while pure UO 2 nanoparticles were collected at 280 °C and higher temperatures. The average size of these nanoparticles varied in the range of 250–450 nm, which could be adjusted by tuning the reaction temperature and incubation time. Longer incubation time led to slight size increase due to Ostwald ripening . The mixture precursor took shorter time to transform to UO 2 at higher temperatures. A possible synthesis mechanism was proposed, including three stages: (I) initial precursor formation and transformation, (II) mid-term formation of ianthinite and UO 2 , and (III) the final formation of UO 2 nanoparticles. This research provides a facile method for the synthesis of UO 2 nanoparticles with excellent size stability in a relatively wide range of experimental conditions. Moreover, this method provides a new way for synthesis of ianthinite, a rare and hard-to-synthesize hydrous uranyl oxide .
研究领域:
材料科学
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核化学
·
纳米技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 23
·15910-15917
·
IF 3.9
Zhanjun Zhang,Qipeng Liu,Dashu Pan,Yubing Xue,Xiaojuan Liu,Jing Zhao,Yinggen Ouyang,Xiaofan Ding,Songtao Xiao,Qingyuan Yang
In order to solve the problem that UO2 in direct ethanol fuel cell anode catalysts is easily lost in acidic solution, resulting in the degradation of catalytic performance, this paper prepared a C/UO2/PVP/Pt catalyst in three steps by adding polyvinylpyrrolidone (PVP). The test results by XRD, XPS, TEM and ICP-MS showed that PVP had a good encapsulation effect on UO2, and the actual loading rates of Pt and UO2 were similar to the theoretical values. When 10% PVP was added, the dispersion of Pt nanoparticles was significantly improved, which reduced the particle size of Pt nanoparticles and provided more ethanol electrocatalytic oxidation reaction sites. The test results by electrochemical workstation showed that the catalytic activity as well as the stability of the catalysts were optimized due to the addition of 10% PVP.
研究领域:
材料科学
·
电化学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Liang Cheng,Rui Gao,Biaojie Yan,Zhenliang Yang,Bingqing Li,Qingdong Xu,Pengchuang Liu,Mingfu Chu,Bin Bai,Pengcheng Zhang
UO 2 –Mo composites are expected to be candidate materials for use as enhanced thermal fuel in the next generation of high-level safety reactors. Nevertheless, the UO 2 matrix tends to create micro-cracks caused by thermal stress generated during the sintering process. A novel type of UO 2 –Mo-SiC w composite is fabricated by spark plasma sintering (SPS) to enhance the thermal-mechanical properties of UO 2 . In the composite, SiC w is dispersed uniformly in the UO 2 matrix to form microspheres , and Mo is distributed in a three-dimensional network to form heat-conduction channels. Micro-cracks in the UO 2 matrix are significantly suppressed in the UO 2 –Mo composite, since only a small amount of SiC w is incorporated into the UO 2 . Indentation testing indicates a great capability of the SiC w to sharply enhance the crack propagation resistance of the UO 2 matrix. The estimated indentation fracture toughness reaches 0.91 MPa m 1/2 with the incorporation of 0.5 vol% SiC w , representing a 68.5% improvement over the value of 0.54 MPa m 1/2 obtained for the UO 2 –Mo composite. The thermal conductivity of the UO 2 –4Mo composite at 1000 °C was enhanced by approximately 54.3%, 60.1% and 67.2% for a SiC w content of 0.5, 2, and 4 vol%, respectively, compared with pure UO 2 . These results provide new insight for further improving the safety and lifespan of UO 2 fuel in reactors.
研究领域:
核工程
·
材料科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Liang Cheng,Biaojie Yan,Rui Gao,Xiangdong Liu,Zhenliang Yang,Bingqing Li,Yi Zhong,Pengchuang Liu,Yun Wang,Mingfu Chu,Bin Bai,Pengcheng Zhang
UO 2 /Mo composite pellets with enhanced thermal conductivity have been considered for the novel construction of high-safety fuel systems. UO 2 /Mo core-shell composite pellets with a reasonable porosity of 4–5% were fabricated by spark plasma sintering (SPS). In the SPS UO 2 /Mo composite, the majority of pores remained homogeneous in the UO 2 matrix, while it had a dense morphology in the continuous Mo channel for the heat conduction . The sintering behaviour of the UO 2 /Mo composite indicated that the incorporating Mo impeded densification of UO 2 , and the primary densification temperature ranged from 903 K to 1270 K. To introduce 2 vol% Mo to UO 2 , the thermal conductivity (TC) was enhanced to 4.02 W/m·K at 1073 K. The above result represented a 23.31% improvement over the value of 3.26 W/m·K (Fink) for a pure UO 2 pellet, which was approximated by the revised Hasselman-Johnson model. In particular, the coefficient of thermal expansion (CTE) was reduced to 10.0 × 10 −6 /K from 298 K to 1673 K, representing an 8.83% reduction from the value of 10.98 × 10 −6 /K (Martin) for a pure UO 2 pellet. The reduction effect on the CTE was superior to that of other UO 2 matrix composites fuel systems and, hence, offers an external safety aspect for reactors at the elevated temperatures close to accident conditions. These results provide a feasible method for the fabrication of a UO 2 /Mo core-shell pellet as an accident tolerant fuel.
研究领域:
核能工程
·
材料科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Dezhi Zhang,Yingru Li,Bingqing Li,Zhenliang Yang,WeiZhen Man,Linli Tan,Jianfeng Tan,Mingfu Chu,Pengcheng Zhang,Rui Gao,Xinchun Lai
In this paper, two kinds of composites constructed by UO 3 nanoflakes (which is UO 3 ·yNH 3 ·xH 2 O, precisely) and different graphene oxide (GO) nanosheets (homemade GO, GO-h, and commercial GO, GO-c) were prepared via solution chemical reaction. The two kinds of GO share similar morphology and possess the same species of functional groups. Nevertheless, GO-h possesses higher oxidization degree and thus could adsorb more uranyl ions, and the corresponding composite shows a much more regular shape: UO 3 nanoflakes and GO nanosheets cross each other, which would help overcome the disadvantage of graphene aggregation. As a result, homemade reduced graphene oxide (RGO-h) sheets inside the final UO 2 pellets (named as UO 2 /GO-h) could construct a well-bulit thermally conductive network to enhance its thermal conductivity . However, similar RGO-c network cannot be observed in the UO 2 /GO-c pellest originated from GO-c. Therefore, only the thermal conductivity of UO 2 /GO-h pellet acquires a dramatic increase, 37.30% relative to UO 2 pellet at 1200 °C, showing that UO 2 /GO-h possesses great potential for the development of novel UO 2 -based ATF fuels.
研究领域:
材料科学
·
核能工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 10
·7031-7039
·
IF 3.9
Pei Wu,Liqin Wang,Jinrui Wang,Junhan Luo,Yuexiang Lu,Xiaopeng Song,Jilian Liu,Yongquan Qin,Liudong Hou,Jing Ma
This study focuses on the recovery of UO2 from oxide spent fuel using electrodeposition. U3O8 was used as the initial material and dissolved in NaCl–2CsCl using NH4Cl at high temperatures by means of chlorination reaction. The electrolysis process was conducted using a three-electrode system to investigate the effects of cathode material and diameter, electrolysis temperature, electrolysis time, electrolysis voltage, and uranium concentration in the molten salt on the electrolysis reaction. By optimizing the electrolysis conditions, pure UO2 with a recovery efficiency of 97% was obtained, and the products were characterized using XRD, SEM-EDS, ICP-AES and XPS. It was found that within the scope of this experiment, increasing the cathode diameter, extending the electrolysis time, and increasing the reduction voltage appropriately all led to an improvement in the recovery efficiency of the electrolysis reaction, while other conditions had minimal effect on the reaction. Furthermore, doping of the electrolyte system was performed by adding La, Ce and Nd elements, while the removal of La showed good purification effects, with a maximum decontamination factor of 119. Furthermore, the system showed good purification effects for Nd, with a decontamination factor of 57.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Junhan Luo,Qi Qing,Zhe Wang,Shuang Liu,Jing Chen,Yuexiang Lu
Nano-sized UO 2 particles have great application potential in the field of nuclear fuel fabrication and catalysis, while most of the current synthesis methods either cannot obtain products with high stability or need to introduce organic agents which would cause organic residue pollution. Herein, we have developed a new synthesis method by combining the microplasma gas electrode with molten salt electrochemistry. Uranyl ions (UO 2 2+ ) in molten salt can be directly reduced to UO 2 nanoparticles at the interface between plasma and molten salt. These particles have uniform size distribution, strong crystallization and high purity, with no organic reagent contamination or volatilization concerns, and show good long-term oxidation resistance in water, without any change for more than 30 days. The effects of electrolytic parameters such as electrolytic time, melt temperature, initial UO 2 2+ concentration, and electrolytic current on the composition and size of the products have been studied. It is found that these electrolytic parameters have little effect on the composition of the products, which are all UO 2 , but strongly affect the size. The average particle size increased with electrolysis time, temperature, and the initial UO 2 2+ concentration increased. According to these phenomena, the size of the product can be regulated at the range of 20–200 nm.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zhenliang Yang,Bingqing Li,Jingkun Xu,Yi Zhong,Liang Xie,Mingfu Chu,Yun Wang,Rui Gao,Libing Yu,Mingshan Wang,Guoliang Zhao,Pengcheng Zhang,Bin Bai,Chen Xu
Two strategies have been extensively employed to develop advanced accident tolerant fuels (ATF): improving thermal conductivity and producing large grain sized pellets. However, there are few reports on the simultaneous utilization of both strategies. In this work, we fabricated Mo–Cr alloy reinforced UO 2 (UMC) composite pellet with both high thermal conductivity and large grain size by a simple in-situ alloying method for the first time. The average grain size of UO 2 increased from 6 μm to 113 μm. Thermal conductivity of the UMC pellet (with 2 vol% Mo) at 1200 °C increased by 36.46% compared with pure UO 2 . The increase rate of thermal conductivity per 1 vol% dopant reached about 18%. The Mo–Cr alloy formed continuous micro-cell layer around UO 2 particles. Such continuous micro-cell Mo–Cr alloy layer and increase of UO 2 grain size both helped improve the thermal conductivity of UMC composite pellets. Thermal expansion coefficient of the UMC under the operating temperature decreased by 11.90% compared with pure UO 2 . The oxidation resistance of the UMC pellet under high temperature steam was also improved. This work provides a new strategy towards fabricating ATF with both high thermal conductivity and large grain size.
研究领域:
核能工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2021
·Vol. 5
·期 1
·184-194
·
IF 5.693
Liang Ying,Xia Meng,Yu Qiuhan,Li Yongpeng,Sui Zhuyin,Yuan Yihui,Hu Xin-Ming,Chen Qi,Wang Ning
Uranium, which was abundant in the ocean but existed in the form of uranyl tricarbonate ([UO 2 (CO 3 ) 3 ] 4− ) with an extremely low concentration of 3.3 ppb, was a significant element of nuclear energy. It is of immediate significance to the research into uranium extraction by the exploration of adsorbents for environment and resource sustainability. Herein, the new ionic covalent organic frameworks (iCOFs) named COF-DG containing the guanidine groups was designed and synthesized via Schiff base reaction between diaminoguanidine hydrochloride and 1,3,5-triformylphloroglucinol. The adsorption performance indicated that the COF-DG possessed an uptake capacity of 65.6 mg g −1 toward the [UO 2 (CO 3 ) 3 ] 4− , attributed to the chemical interaction and anion exchange between [UO 2 (CO 3 ) 3 ] 4− and the cationic COF-DG with Cl − , as well as the electrostatic attraction. Besides, the COF-DG exhibited a higher affinity and selectivity toward [UO 2 (CO 3 ) 3 ] 4− in the presence of the competing anions. Furthermore, the COF-DG displayed an antibacterial rate of 82% against Gram-negative bacteria Escherichia coli owing to the guanidine groups. This work contributes new insights into the further development of iCOFs, for applying as a potential candidate in uranium extraction from seawater in practical engineering. Graphical abstract The new ionic covalent organic frameworks named COF-DG was designed and exploited via Schiff base reaction, which exhibited a higher affinity and selectivity toward the [UO 2 (CO 3 ) 3 ] 4− .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）