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Phase evolution of Nd 3+ -doped natural garnet minerals systems: A potential host phase for trivalent actinide immobilization
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| 【文章作者】Ge, Yong;Li, Shuyang;Liao, Yiliao;Xu, Baoliang;Ji, Shiyin;Zhang, Shengtai;Tang, Kui;Duan, Tao |
| 【文章摘要】 The immobilization of long-lived actinides produced from spent fuel reprocessing poses a significant environmental concern. In this work, we synthesized glass-ceramics at low temperatures using natural garnet minerals as precursors to immobilize trivalent actinides. Two primary metrics, the quantitative distribution of Nd3+ in glass-ceramics and its leaching rate, were employed to explore the mechanism of Nd3+ immobilization in glass-ceramic products. XRD results show that the primary crystalline phase of the glass-ceramics transitions from calcium feldspar and spinel to oxyapatite with increasing Nd2O3 content. Within a specific range, the proportion of Ca2Nd8(SiO4)(6)O-2 in the samples increases from 37.9 % to 57.9 % with rising Nd2O3 content, while the glassy phase proportion decreases. The distribution of Nd3+ in Ca2Nd8(SiO4)(6)O-2-based glass-ceramics was quantitatively investigated using a combination of TEM-EDX and Rietveld refinement calculations. Nearly 70 % of Nd was found to benefit from a double sealing barrier (Oxyapatite + glass) even under high Nd2O3 loading. A 42-day leaching experiment was conducted using deionized water as the medium. The data demonstrated that Ca2Nd8(SiO4)(6)O-2-based glass-ceramics exhibited a lower Nd-normalized leaching rate(LRNd similar to 10(-5) g m(-2) d(-1)) in solution compared to products solely relying on the glass network for actinide immobilization. This work introduces a cost-effective natural solution for trivalent actinide immobilization. |
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【卷】【ISSUE】【ISSUEID】
【文章期份】2024
【发布日期】2025/5/13 10:04:15
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