The enhanced dissolution of uranium oxides by the application of ultrasound
in supercritical fluid carbon dioxide containing dissolved 4,4-trifluoro-1
-(2-thienyl)-1,3-butanedione and tributyl phosphate is demonstrated. Under
conditions of 60 degreesC and 150 atm. the steady state dissolution of UO3
with sonification is increased by approximately 100%. Furthermore, the effe
ct of adding hydrogen peroxide to the supercritical system above enables th
e lower oxides of uranium, UO2 and U3O8, to be extracted. (C) 2001 Society
of Chemical Industry.