The thermodynamics of extraction of Am(III) and Eu(III) from nitrate solution by neutral phosphorus-based organic compounds

Abstract

The extraction of Eu(III) and Am(III) from lithium nitrate solution by several neutral phosphorus-based extractants has been studied as a function of temperature in the range of 0–50°C. From the variation of the distribution ratio with temperature the thermodynamic quantities ΔG, ΔH and ΔS have been calculated for these extractions. The results of this study indicate that these two metal ions behave quite similarly in respect to the basicity and the steric bulk of the extractant molecules. Extraction of these metals is enhanced significantly with increasing basicity of the extractant but is inhibited with increasing steric bulk of the phosphorus compounds.