Supercritical Carbon Dioxide Extraction of Uranium from Acidic Medium Employing Calixarenes

作者：Rao Ankita; Rathod Nilesh V; Malkhede Dipalee D; Raut Vaibhavi V; Ramakumar K L^*

来源：Separation Science and Technology (Philadelphia), 2013, 48(4): 644-651.

DOI：10.1080/01496395.2012.707731

• calixarene
• carbon dioxide
• counter ion
• supercritical fluid extraction
• uranium

Various calixarenes were evaluated for the supercritical fluid extraction of uranium from nitric acid medium. The extraction efficiency was found to be affected by various parameters, namely pressure, temperature, CO2 flowrate, extraction time, and molarity of nitric acid. The addition of HPFOA (pentadecafluoro-n-octanoic acid) for the production of CO2-phillic fluorinated counter ion enhanced the extraction efficiency. Under optimized conditions (pressure of 200atm, temperature of 323K, 30minutes of static time followed by 30minutes of dynamic time, CO2 flowrate of 2mL min1, nitric acid molarity of 0.1M) for uranium: calixarene: HPFOA mole ratio of 1:5:10, highest extraction efficiency could be obtained with p-tert.-butyl calix[6]arene (79.9%). Solvent extraction study with hexane as the organic phase indicated the formation of [UO2 (calixarene)]2+. In order to assess the suitability of the developed method to extract uranium in the presence of a host of other ions, extraction efficiency for other metal ions was estimated.

• 出版日期2013-1-1