Use of two-phase aqueous systems based on polyethylene glycol for isolation and separation of americium in different oxidation states

Extraction of americium in higher oxidation states in two-phase systems on the basis of polyethyleneglycol (PEG) without organic solvents from concentrated carbonate solutions in the presence of alizarin and from solutions of ammonium sulfates in the presence of arsenazo 3 for different concentrations of Am in solutions is studied by the method of spectrophotometry. During extraction from K2CO3 (40 mass%) solutions for Am(3) the distribution factor D= 43.7, for Am(5)-7.3; for Am(6)-33.2, Am(4)-40.8. Reduction of Am(6) to Am(5) permits to isolate microamounts of Am from Cm(3) (D=127.8). In the presence of 10-3M arsenazo 3 with pH increase from 2.1 to 4.0 the value of D for Am(3) increases from 0.30 to 46.20, for Am(4) - from 1.04 to 57.51, fo Am(5) from 0.23 at pH 3 to 52.72 at pH4. Thus, two-phase system on the basis of PEG can be used for isolation and separation of Am in different oxidation states. 3 refs.; 3 figs.; 2 tabs