Selective metal extraction from solid matrices with TBP complex with nitric acid in supercritical carbon oxide

在超临界二氧化碳中用 TBP 与硝酸络合物从固体基质中选择性萃取金属

• 批准号: 13480145
• 负责人: ENOKIDA Youichi
• 金额: $ 7.94万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13480145/
• 关键词: lanthanides; metal extraction; tri-n-butylphosphate; supercritical fluid; nitric acid complex; carbon dioxide; ultrasound; 超音波; 超臨界流体抽出; 環境調和

Selective recovery of lanthanide elements from a mixture of metal oxides was demonstrated using tri-n-butylphosphate complex with nitric acid and water dissolved in supercritical carbon dioxide (SF-CO_2). Recovery yields were experimentally evaluated under various temperatures and pressures ; influences of temperature and pressure were studied and optimum conditions for metal extraction were determined. Higher temperature is preferable for rapid dissolution because of activation energy. Concerning with pressure, the optimum value exists because density becomes larger, but mole fraction of the complex decreases as pressure increases. The optimal pressure is very close to the critical point for the mixture of the complex, and SF-CO_2. To study mechanisms of selective dissolution and extraction of metals form their oxides, dissolution and extraction rates was correlated with the mole ratios of TBP/HNO_3/H_2O and a fact that, the higher ratios of HNO_3/TBP and, H_2O/TBP are preferable was found. ^3H-NMR measurements on TBP complex supports that TBP complex contains a solvent structure of reverse micelle like. It was also found that ultrasound application is so effective that it may enhance the extraction rates ten times larger than without its application. The solubility of TBP complex in SF-CO_2 was well predicted by a molecular simulation.

研究了三正丁基磷酸配合物在超临界二氧化碳（SF-CO_2）中与硝酸和水相结合，从金属氧化物混合物中选择性回收镧系元素的方法。实验评估了不同温度和压力下的回收率；研究了温度和压力对金属提取的影响，确定了最佳提取条件。由于活化能的关系，较高的温度有利于快速溶解。随着压力的增加，配合物的摩尔分数随压力的增加而降低，但密度越大，配合物的摩尔分数越高。最佳压力非常接近配合物与SF-CO_2混合物的临界点。为了研究金属氧化物的选择性溶解和萃取机理，发现溶解和萃取速率与TBP/HNO_3/H_2O的摩尔比有关，HNO_3/TBP和H_2O/ t_2o的摩尔比越高越好。^对TBP配合物的3H-NMR测量支持TBP配合物具有类似于反胶束的溶剂结构。我们还发现，超声波的应用是非常有效的，它可以提高提取率十倍以上没有它的应用。通过分子模拟，预测了TBP配合物在SF-CO_2中的溶解度。

项目成果

Y.Enokida et al.: "Ultrasound Enhanced Dissolution of UO2 in Supercritical CO2 Containing a CO2-Philic Complexant of Tri-n-butylphosphate and Nitric Acid"Industrial and Engineering Chemistry Research. 41. 2282-2286 (2002)

Y.Enokida 等人：“超声增强 UO2 在含有磷酸三正丁酯和硝酸的亲 CO2 络合剂的超临界 CO2 中的溶解”工业和工程化学研究。

Y.Enokida, I.Yamamoto: "Vapor-liquid equilibrium of UO2(NO3)2 2TBP and supercritical carbon dioxide mixture"Journal of Nuclear Science and Technology. (in press). (2002)

Y.Enokida，I.Yamamoto：“UO2(NO3)2 2TBP与超临界二氧化碳混合物的汽液平衡”核科学与技术杂志。

Y.Enokida et al.: "Characterization of a tri-n-butyl phosphate-nitric acid complex : a CO_2-soluble extractant for dissolution of uranium dioxide"Industrial and Engineering Chemistry Research. 42. 5037-5041 (2003)

Y.Enokida等人：“磷酸三正丁酯-硝酸络合物的表征：用于溶解二氧化铀的CO_2可溶萃取剂”工业和工程化学研究。

K.Sawada, O.Tomioka, Y.Enokida, I.Yamamoto et al.: "Density of supercritical fluid containing UO_2(NO_3)_2-TBP complex and CO_2"Proceedings of Global 2003. 1. 707-710 (2003)

K.Sawada、O.Tomioka、Y.Enokida、I.Yamamoto 等：“含有 UO_2(NO_3)_2-TBP 络合物和 CO_2 的超临界流体的密度”Proceedings of Global 2003. 1. 707-710 (2003)

Y.Enokida et al.: "Ultrasound Enhanced Dissolution of UO2 in Supercritical CO2 Containing a CO2-Philic Complexant of Tri-n-butylphosphate and Nitric Acid"Industrial and Engineering Chemistry Research. (in press). (2002)

Y.Enokida 等人：“超声增强 UO2 在含有磷酸三正丁酯和硝酸的亲 CO2 络合剂的超临界 CO2 中的溶解”工业和工程化学研究。