Extraction processes and solvents for recovery of cesium, strontium, rare earth elements, technetium and actinides from liquid radioactive waste

A method for selectively recovering cesium, strontium, rare earth elements, actinides and technetium from aqueous acidic radioactive waste comprising the steps of:

• (a) contacting the aqueous acidic radioactive waste with an extracting agent solution of a complex organoboron compound and a substituted or unsubstituted polyethylene glycol in an organofluorine diluent mixture, to extract cesium and strontium into an organic phase, and leaving the rare earth elements, actinides and technetium in an aqueous phase;
• (b) contacting the organic phase from step (a), containing cesium and strontium, with a strip reagent to strip cesium and strontium from the extracted organic phase into an aqueous phase;
• (c) contacting the aqueous phase from step (a) with an extracting agent solution of a phosphine oxide in a saturated hydrocarbon diluent, to extract rare earth elements, actinides and technetium, into an organic phase;
• and
• (d) contacting the organic phase from step (c) containing rare earth elements, actinides and technetium, with a strip reagent to strip the rare earth elements, actinides and strontium into an aqueous phase.