Extraction of uranium from phosphoric acid by solvent approaches using D2EHPA and TOPO: Experimental design with environmental implications

Laboratory of Applied Geophysics of Geotechnical Geology of Engineering and Environment (L3GIE), Mohammadia School of Engineers, Mohammed V University, Rabat, Morocco.

^* Corresponding author: asmaeajabli@gmail.com

Abstract

With the current nation's great demand for nuclear power, the importance to recover uranium from phosphoric acid has become relevant, Solvent extraction is one of the most effective uranium recovery methods. For example, to extract uranium, processes like Oak Ridge, Urphos, OPAP (Organic Phosphoric Acid Process), and OPPA (Organophosphorus Pro- cess for Phosphoric Acid) use solvents such as di (2ethylhexyl) phosphoric acid (D2EHPA) and trioctylphosphine oxide (TOPO). In this work, a mix- ture consisting of D2EHPA and TOPO accepts that kerosene as solvent is used for uranium recovery from phosphoric acid through solvent extrac- tion. Several operation parameters are changed to study their influence in the extraction process, such as for example: the extractant concentration, extraction time (2–20 min), organic/aqueous phase ratio (0.5–3) and phos- phoric acid concentration (4–6 M). A box Behnken is applied to optimize the process conditions and reveal the interactions among variables. Prelim- inary results demonstrate that the D2EHPA–TOPO mixture diluted in ker- osene can achieve substantial uranium extraction yields (90–95%) under optimal conditions. In addition, this study proposes a process that is envi- ronmentally advantageous, it significantly lowers carbon emissions, con- tributes to cleaner fertilizer production, and supports a more sustainable and efficient management of uranium resources.