Hosseinpour Khanmiri Mohammad, Bogdanov Roman, Puchkova Elena, Titov Anatoly, Yadollahi Ali
Nuclear Science and Technology Research Institute, AEOI, Tehran, 14893-836, Iran.
Department of Radiochemistry, Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia, 199034.
Sci Rep. 2024 Aug 3;14(1):17992. doi: 10.1038/s41598-024-68984-6.
In the study presented here, the initial (that is, before the start of the process of natural hydrochemical influence) mineral formula of metamict polycrase in the composition of granite pegmatites of the Baltic Shield, applying an uranium natural half-leaching period, was calculated. To investigate the characteristics of immobilization of actinides in the studied polycrase, the absolute and relative uranium contents are compared with the corresponding uranium contents in the original betafite of the same deposit and age. It has been shown that over its geological history, betafite has lost up to 80% of its original uranium content. The proportion of uranium preserved in polycrase is twice as high. It is concluded that the difference in the relative content of uranium (27.3 wt% in polycrase and 31.6 wt% in betafite) cannot be the only reason for the complete oxidation of uranium in betafite, given that in polycrase 30% of uranium is preserved in the tetravalent state. It is more likely that the oxidation of uranium in betafite was primarily a result of the low ionicity of the chemical bonds compared to that in polycrase. This allows us to consider minerals of the euxenite group to be quite promising as matrix materials for the immobilization of actinides. At the same time, an opinion was expressed on the advisability of further comparative studies of Nb-Ta-Ti-oxides of the mineral groups ABO and ABO for their use at the final stage of the nuclear fuel cycle.
在本文介绍的研究中，利用铀的天然半浸出期，计算了波罗的海盾地花岗岩伟晶岩中变晶复稀金矿的初始（即自然水化学作用开始之前）矿物配方。为了研究锕系元素在研究的复稀金矿中的固定特性，将绝对和相对铀含量与同一矿床和年龄的原始钛铌钙铈矿中的相应铀含量进行了比较。结果表明，在其地质历史中，钛铌钙铈矿已损失高达其原始铀含量的80%。复稀金矿中保留的铀比例则高出一倍。得出的结论是，考虑到复稀金矿中30%的铀以四价态保留，铀相对含量的差异（复稀金矿中为27.3 wt%，钛铌钙铈矿中为31.6 wt%）不可能是钛铌钙铈矿中铀完全氧化的唯一原因。更有可能的是，与复稀金矿相比，钛铌钙铈矿中铀的氧化主要是由于化学键的离子性较低。这使我们能够认为黑稀金矿族矿物作为锕系元素固定的基质材料很有前景。同时，有人对进一步比较研究ABO和ABO矿物组的铌 - 钽 - 钛氧化物在核燃料循环最后阶段的适用性发表了看法。
