Abstract
In this paper preliminary results of studies concerning the extraction of uranium(VI) from soils in aqueous PEG (1550) 20 % - Na₂SO₄ 20 % - Na₂CO₃ 10-2-10-3 M two-phase systems are presented, as well as the spectrophotometric determination of extracted uranium with pirocatechol violet (PV). A special attention was given to the experimental factors (pH, redox potential, CO₃^2- anion concentration and initial uranium concentration), which was found to influence both the formation and stability of aqueous two-phase extraction system, and the values of extraction parameters. The experimental values of distribution coefficients, extraction degree and enrichment coefficients for U(VI) extraction indicate an acceptable separation at pH=4-5, and at pH=8-9, respectively. Under certain work conditions, the increasing of U(VI) concentration in initial solution and of CO₃^2- anion concentration determined an increase of extraction degree and of enrichment coefficient.