Dialkylhydrogen phosphonates have emerged as potential extractants for extraction and recovery of actinide species from different environments. The applicability of diamylhydrogen phosphonate (DAHP) as a ligand in supercritical medium was evaluated by measuring its solubility in supercritical carbon dioxide. The solubility behaviour is examined at 313K to 343K, with pressure ranging from 10MPa to 20MPa using a flow saturation method. The solubility of DAHP ranges from 0.92 × 10mol∙mol to 61.1 × 10mol∙mol. Thermodynamic consistency of the solubility at different isotherms is verified using Valderrama and Zavaleta test. The solubility data was modelled using Chrastil, Mendez-Teja, Adachi-Lu, Wei-Wang and Keshmiri equations. The performance of these models is compared using average deviation and Akaike information criteria. Using the solubility data, supercritical fluid extraction method has been developed and demonstrated for selective recovery of uranium from uranium-aluminium based alloy.

中文翻译：

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膦酸二戊酯在超临界二氧化碳中的溶解度和萃取研究

二烷基氢膦酸盐已成为从不同环境中提取和回收锕系元素的潜在提取剂。通过测量膦酸二戊酯（DAHP）在超临界二氧化碳中的溶解度来评估其作为配体在超临界介质中的适用性。使用流量饱和法在 313K 至 343K、压力范围从 10MPa 至 20MPa 下检查溶解度行为。DAHP 的溶解度范围为 0.92 × 10mol·mol 至 61.1 × 10mol·mol。使用 Valderrama 和 Zavaleta 测试验证了不同等温线下溶解度的热力学一致性。使用 Chrastil、Mendez-Teja、Adachi-Lu、Wei-Wang 和 Keshmiri 方程对溶解度数据进行建模。使用平均偏差和 Akaike 信息标准来比较这些模型的性能。利用溶解度数据，开发并论证了超临界流体萃取方法，用于从铀-铝基合金中选择性回收铀。