Extraction of Americium(III) and Europium(III) with Two Open-Chain Crown Ethers of Amide Type

The extraction of Am³⁺ and Eu³⁺ from aqueous picric acid solution by N, N-dinaphthyl-N, N-diphenyl-3,6-dioxaoctanediamide (L^I) and 1, 1-(3, 6, 9-trioxaundecanedionyl)diphenothiazine (L^II) was investigated by a radioactive tracer technique. Extraction distribution ratios of Am³⁺ and Eu³⁺ have been measured as a function of pH, picric acid concentration, extractant concentration, diluent and temperature. The extraction of Am³⁺ is preferred to that of Eu³⁺ for both L^I and L^II, and the latter gives larger separation factor than the former. The equilibrium constants and thermodynamic parameters of extraction reactions were also calculated.