The recovery of uranium from irradiated thorium by extraction with di-1-methyl heptyl methylphosphonate (DMHMP)/n-dodecane

The process using DMHMP as extractant for the recovery of uranium from irradiated thorium was proposed. Firstly, the process parameters, including concentration of DMHMP, concentratation of HNO3 in feed, scrub and stripping solution, and phase ratio, were systematically optimized by batch extraction experiment. Then, a batch multistage countercurrent extraction simulation experiment was used to verify and test the process. Finally, the irradiation stability of DMHMP was assessed and compared with TBP. The results indicate that DMHMP is a potential candidate for the separation of U(VI) from bulk Th(IV). Furthermore, the complexes of U(VI) and Th(IV) with DMHMP were also demonstrated. (C) 2017 The Authors. Published by Elsevier B.V.