Solvent Extraction for Uranium Recovery and Impurity Rejection

A novel uranium beneficiation process has been developed by Insight R&D inc. for Global Atomic Corporation (GAC) to process ores produced by the DASA uranium mine in Niger. The process consists of comminution, acid pugging and leaching, solvent extraction, and precipitation. Solvent Extraction (SX) is used to selectively separate uranium from impurities in the leach solution. A tertiary amine extracts the uranyl cation into the organic phase but also has a tendency to carry over some impurities. Scrubbing is utilized to address some of this carry-over followed by stripping. Stripping transfers the extracted cations from the loaded organic to an aqueous phase. In this work two stripping agents (sodium chloride and sodium carbonate) were explored at pilot-scale and their advantages and disadvantages assessed for downstream product quality. Upon stripping agent selection, the SX reagent concentrations were optimized utilizing METSIM^® to minimize carry over of acid and impurities from the front to the back end of the SX circuit.