JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
Gao Kai,Shi Yunfeng,An Kexin,Tan Jun,Zhang Yanna,Dong Jiajie,Yu Weiyue,Lin Haipeng
A hydrothermal method which can convert free cesium ions into stable pollucite at low temperatures was established in this work, avoiding any evaporation pollution during the disposal of cesium containing waste. Meanwhile, rapid synthesis under hydrothermal conditions was achieved using seed guidance, which shorten the growth time of pollucite crystals to 8 h, and making the treatment and disposal of cesium containing wastewater faster. Standard leaching test results show that the leaching rate of Cs was very low (< 3.5 × 10 −7 g·m 2 ·d), it still has good thermal stability at a temperature of 1300 °C, when the cesium content in pollucite reaches 20%.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Yiping Tan,Shuangke Li,Xiaoping Xu,Pan Chen,Zhiyong Gao,Wei Sun,Belinda McFadzean,Jian Cao
Quartz and feldspar are the primary impurities in the mineral processing of pollucite. Due to the highly similar surface properties of these three minerals in terms of physicochemical characteristics, achieving efficient flotation enrichment of pollucite has been a challenging problem. To address this issue, the development of flotation collectors with high selectivity towards pollucite is crucial. In this study, different-sized crown ethers acted as selective collectors for the direct flotation to detach pollucite from feldspar and quartz were investigated, leveraging the selective bonding of crown ethers to alkali metal active site on the surface of pollucite. The properties of 21-crown-7 ether (21C7), benzo-21-crown-7 (B21C7) and dibenzo-21-crown-7 (DB21C7) (with three different cavity sizes) were investigated as collectors for pollucite flotation. The experimental results indicated that DB21C7 exhibited the best collecting performance. The mechanism was studied through various experimental measurements and computational simulations, and the results revealed that the selective adsorption mechanism of crown ethers onto the surface of pollucite was achieved through a combination of chelation interaction involving “spatial effect” and hydrogen bonding interaction. This work has disclosed that crown ether compounds may hold significant potential as collectors for flotation of pollucite.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Gongcheng Xing,Mengxuan Tao,Zhiyu Gao,Shuoting Chen,Song Wang,Guogang Li
In this work, two component substitution types of Si 4+ →[Cs + -Al 3+ ] and [Mg 2+ -Mg 2+ ]→[Cs + -Al 3+ ] were successfully designed in Eu 2+ -doped CsAlSi 2 O 6 pollucite phosphors. The photoluminescence color can be controllably tuned from cyan (513 nm) to blue (437 nm), and full width at half maximum (FWHM) can be adjusted in the region of 79–169 nm. Besides, the thermal stability is obviously improved, where PL intensity at 200 °C increases from 59% (CsAlSi 2 O 6 :5%Eu 2+ ) of the original intensity to 96% [(CsAl) 0.6 Mg 0.8 Si 2 O 6 :5%Eu 2+ ] and 86% [(CsAl) 0.9 Si 2.1 O 6 :5%Eu 2+ ], respectively. The corresponding mechanisms of spectral adjustment and thermal stability enhancement were investigated. The proposed strategies can play a key role in exploiting novel and efficient phosphors for high-power w-LEDs lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Guoqiang Zhao,Wanjun Shi,Weidong Ma,Xianzhou Ning,Bo Xie,Wei Zhang,Bin Ye,Yushan Yang
The present work developed pollucite-based waste forms suited for the immobilization of cesium- and strontium-rich waste (CSRW) derived from the TRPO process. The sintering conditions and waste loading were varied, and their effects on waste forms phase composition, microstructure, mechanical properties and durability were investigated. It was found that with a CSRW loading of 7.5 wt% and sintered at 1150 °C for 4 h, CSRW could be effectively incorporated into the pollucite waste forms, with only a minor glass phase present. The corresponding waste forms exhibited a microhardness of ∼ 563 HV and a thermal conductivity of ∼ 1.36 W·m -1 ·K -1 . Moreover, the normalized leaching rates of Cs, Sr, Ba, Rb, Fe, and Mo were 3.07×10 -2 , 2.76×10 -2 , 3.3×10 -3 , 9.9×10 -3 , 3.9×10 -3 and 3.1×10 -3 g·m -2 ·d -1 and the leaching indexes were > 9, exhibiting good chemical durability. This work demonstrated the feasibility of pollucite as a stable host material for the immobilization of CSRW.
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2016
·Vol. 99
·期 11
·3784-3791
·
IF 2.787
Jingkun Yuan,Peigang He,Chao Yang,Dechang Jia,Jinsong You,Shu Yan,Delong Cai,Zhihua Yang,Xiaoming Duan,Shengjin Wang,Jiahuan Xu,Yu Zhou
The purpose of this work was to study the role of lithium in cesium-based geopolymers and the thermal evolution during heat treatment together with thermal expansion behavior of the resulting geopolymer ceramic. A series of lithium-substituted cesium-based geopolymers, Cs (1− x ) Li x GP (where x = 0, 0.1, 0.2, and 0.3), were prepared. All the geopolymer samples were heated at 1300°C for 2 h and thermal evolution on heating was studied by a variety of techniques. Phase composition, microstructure evolution, and thermal expansion behaviors of the ceramics derived from the geopolymers were characterized. All the geopolymer specimens exhibited similar thermal evolutionary trends. With increases in lithium content, overall mass loss increased gradually due to the higher hydration energy of Li + than Cs + . Thermal shrinkage of these specimens can be divided into four stages, i.e., structural resilience, dehydration, dehydroxylation, and sintering, according to the dilatometer results. The introduction of Li results in two-step sintering behavior for the lithium-substituted cesium-based geopolymers. The average thermal expansion coefficient (CTE) of Cs (1− x ) Li x GP ceramics decreased from 4.80 × 10 −6 K −1 ( x = 0) to 3.61 × 10 −6 K −1 ( x = 0.3) with increase in lithium substitution. The reason can be attributed to the presence of spodumene after thermal treatment, which has a relatively low thermal expansion coefficient compared with pollucite. Meanwhile, molten spodumene could serve as a buffer phase between pollucite crystals also conducive to the decline of CTE of this system.
研究领域:
材料科学
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无机非金属材料
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陶瓷学
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热物理性能
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固废资源化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）