Solvent Extraction of Strontium From Nitric Acid Solution by Dicyclohexyl-18-Crown-6

Solvent extraction of strontium with dicyclohexyl-18-crown-6 (DCH18C6) from HNO₃ solutions has been investigated. The effect of extraction conditions, such as organic diluents, the concentration of nitric acid, shaking time and temperature was studied. The extraction efficiency of Sr depends on the concentration of HNO₃ and the maximal extraction efficiency (about 92%) of Sr is obtained at 1 mol/L HNO₃. The back extraction efficiency is about (99.56±1.7)% using H₂O as stripping agent. In kinetics studies, the extraction equilibration can be achieved at 10 min for Sr. The negative values of ΔH indicate the exothermic process for extraction of Sr. The selectivity studies show that DCH18C6 is an efficient extractant for strontium ions.