Extraction Mechanism of Rare Earths with Bifuncional Ionic Liquids [A336][CA-12]/[A336][CA-100] in Nitrate Medium

The solvent extraction of rare earths with bifuncional ionic liquids (Bif-ILs) [A336][CA-12]/[A336][CA-100] has been investigated in nitate medium. The extraction abilities for rare earths were compared with organic carboxylic acids CA-12/CA-100 and neutral organophosphorus extractants TBP/P350. The results showed that they were in the descending order; [A336] [CA-12]/[A336][CA-100]>CA-12/CA-100>P350>TBP. The slope analysis method was used to determine the extraction stoichiometry. The extraction mechanisms of rare earths with Bif-ILs [A336][CA-12]/[A336][CA-100] were studied, and it was in accord with complexing mechanism. By studying the effect of extraction equilibration time and temperature on the extraction efficiencies, the results indicated that the extraction process of rare earths with Bif-ILs [A336][CA-12]/[A336] [CA-100] was a fast equilibrium and exothermic reaction. The recycling and stripping experiments indicated that the Bif-ILs extractant has the advantages of high stability and easy stripping, and they are suitable for extracting rare earths