Abstract The study demonstrates the accomplishment of single step, direct supercritical fluid carbon dioxide (SC CO2) dissolution and extraction of uranium from crude matrices viz. yellow cakes (>90%) and rock phosphate ores (70%) employing adducts of trialkyl phosphates and nitric acid, thus avoiding free acid usage and eliminating number of process steps. Rock phosphate ore was made amenable for supercritical fluid extraction (SFE) system by unique strategy of pyrohydrolytic removal of fluorine. Pressure and temperature conditions, which were found to influence uranium extraction efficiency, were optimized at 150 atm. and 323 K. Two milliliter of adduct amount was found to be adequate. Adducts of branched alkyl phosphate, tri-isoamyl phosphate and tri-ethyl hexyl phosphate (TEHP), yield better purity in comparision to straight chain tri-butyl phosphate (TBP).

中文翻译：

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使用超临界二氧化碳从黄饼和矿石基质中直接提取铀

摘要 该研究证明了单步直接超临界流体二氧化碳 (SC CO2) 溶解和从粗基质中提取铀的实现，即。黄饼 (>90%) 和磷矿石 (70%) 使用磷酸三烷基酯和硝酸的加合物，从而避免使用游离酸并减少工艺步骤。通过独特的热水解除氟策略，使磷矿石适用于超临界流体萃取 (SFE) 系统。已发现影响铀提取效率的压力和温度条件在 150 个大气压下进行了优化。和 323 K。发现 2 毫升的加合物量就足够了。支链磷酸烷基酯、磷酸三异戊酯和磷酸三乙基己酯 (TEHP) 的加合物，