Liquid-Liquid Extraction of Uranium from Nitric Acid Solution Using N, N-Di(2-ethyl- hexyl) hexanamide (DOHA) in Dodecane as Extractant

This work describes the liquid-liquid extraction of uranium (U) from 3 mole L-1 nitric acid media by N, N-di(2-ethyl hexyl) hexanamide (DOHA) in dodecane and subsequent determination of uranium using arsenazo III as a chromogenic reagent. Different factors (nitric acid, DOHA, metal ion concentration, salting out effect, temperature and shaking time) affecting the extraction /stripping process, were investigated. The investigation showed that the extraction is independent of the conc. of metal ions in the range of 5 to 300 µg mL-1 and inversely dependent upon the temperature. The desired species so extracted were found to have a stoichiometric composition as UO2(NO3)2.DOHA and UO2(NO3)2.2DOHA at lower and higher concentration of extractant respectively. Uranium could be stripped back from organic phase by using 0.1 mole L-1 ammonium hydroxide (NH4OH) and the extraction was found to be quantitative.

Muhammad Hafeez, Rashida Fiaz, Muhammad Naeem Ahmed, Srosh Fazil, Rizwan Hayder, Akbar Ali and Abdul Majeed Khan