Separation and recovery of uranium and beryllium from acidic sulphate solutions by solvent extraction using mixture of organophosphonic extractants

Abstract

Uranium (U) and beryllium (Be) are strategic critical metals. It is imperative to realize the comprehensive utilization of U or Be poly-metallic resources. This study employed solvent extraction to separate and recover U and Be from a simulated acidic sulphate leachate from a U-Be associated ore. The results indicated that the mixture extractant system containing bis-(2-ethylhexyl) phosphoric acid (D2EHPA) and tributyl phosphate (TBP) had affinity for U, and the selectivity of U towards Be was dependent on the hydrogen ion concentration of the solution. 99.74% U and 6.98% Be were extracted with a two-stage counter-current extraction at sulfuric acid concentration of 1.58 mol/L. By using 2 mol/L Na₂CO₃ solution as the stripping solution, 94.79% U was stripped from the U-loaded organic phase with a one-stage stripping process. After adjusting the pH of the raffinate to 2, with D2EHPA as extractant, 99.76% Be was recovered by performing a two-stage counter-current extraction. Besides, Be could be well stripped from the Be-loaded organic phase with 3 mol/L NaOH solution. And the stripping rate of Be reached 98.85% with a one-stage stripping process. The established method to separate U and Be from sulphate solutions with high acidity has several advantages, including recyclable, reliable, and environmentally friendliness, providing a promising new pathway for the green recovery of U and Be from poly-metallic resources.