Uranium tetrafluoride production using the dropping mercury electrode

Abstract

This work shows the technical feasibility to obtain uranium tetrafluoride through an electrochemical process using a dropping mercury electrode. This product was obtained from ammonium diuranate, dissolved in hydrofluoric solutions, using concentrations of 50 g/L UO2F2. The system was evaluated with current intensities densities from 1.6 to 6.3 A and temperatures from 25 to 65 °C. The maximum current efficiency achieved was 95 %. The UF4 powders achieved spherical morphology, with diameters between 40–60 μm. This property allows correct compaction for the subsequent production of metallic uranium, which allows reaching high-density UF4 – Mg mixtures, between 3.0–3.5 g/cm3, as it was proven in our previous studies. This technique achieved this result thanks to the electrochemical properties of the mercury, when used as cathode. The impurity levels of this product obtained by electrolysis are only those that come from the initial ammonium diuranate concentrates. This method is an alternative to the classic process of UF4 precipitation in an aqueous medium using reducing agents, as the conventional stannous chloride (SnCl2), which commonly contaminate uranium compounds.