Инд. авторы: | Sokol E.V., Kokh S.N., Khoury H.N., Seryotkin Y.V., Goryainov S.V., Novikova S.A., Sokol I.A |
Заглавие: | Natural analogue approaches to prediction of long-term behaviour of Ca2UO5 center dot 2-3H(2)OX-phase: case study from Tulul Al Hammam site, Jordan |
Библ. ссылка: | Sokol E.V., Kokh S.N., Khoury H.N., Seryotkin Y.V., Goryainov S.V., Novikova S.A., Sokol I.A Natural analogue approaches to prediction of long-term behaviour of Ca2UO5 center dot 2-3H(2)OX-phase: case study from Tulul Al Hammam site, Jordan // Arabian Journal of Geosciences. - 2017. - Vol.10. - Iss. 23. - Art.512. - ISSN 1866-7511. - EISSN 1866-7538. |
Внешние системы: | DOI: 10.1007/s12517-017-3305-5; РИНЦ: 32865590; WoS: 000417834100017; |
Реферат: | eng: The Tulul Al Hammam area in central Jordan is an advantageous natural analogue site to study long-term U(VI) retention in similar to 1 Ma old U-bearing combustion metamorphic marbles with clinker-like mineralogy exposed to prolonged supergene alteration for at least similar to 100 kyr. The marbles contain abundant grains of high-temperature (ca. 800-850 degrees C) primary double Ca-U(VI) oxides (mainly Ca3UO6 and CaUO4), which are commonly replaced by hydrated calcium uranates with various impurities (Si, Fe, Al and F). A more hydrous natural analogue of X-phase (Ca2UO5 center dot 2-3H(2)O) occurs as a predominant secondary U compound after primary Ca-U(VI) oxides. The phase was studied by single-crystal XRD, SEM/EDX and electron microprobe (EPMA) analyses and Raman spectroscopy. It is a non-crystalline phase with a specific finger-like microtexture consisting of thin (no wider than 1-2 mu m) lamellar particles. Its Raman spectrum shows a single strong band at 706-713 cm(-1), sometimes coexisting with up to three weak diffuse bands (gamma similar to 390, similar to 540 and 1355-1400 cm(-1)). The find of the natural X-phase (Ca2UO5 center dot 2-3H(2)O) is evidence of its long-term stability in a natural environment. It proves explicitly that the compound Ca2UO5 center dot nH(2)O is a solubility-limiting phase in aged cements. The results have implications for geological disposal of radioactive wastes.
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Ключевые слова: | CD; ORIGIN; ACCIDENT; URANIUM; MAQARIN AREA; HOT PARTICLES; NORTHERN JORDAN; IMMOBILIZATION; Central Jordan; Radwaste management; Cement; X-phase Ca2UO5 center dot 2-3H(2)O; Natural analogue site; Long-term U retention; CEMENT PORE WATERS; ZN; |
Издано: | 2017 |
Физ. характеристика: | 512 |