Strong Acid Stripping of Tertiary Amine for Uranium Recovery

Abstract

A solvent extraction process utilizing 400 g/L H2SO4 for stripping uranium from tertiary amine solvent has been developed for use at the Rabbit Lake mill. The strong acid strip process is made effective by selecting favourable conditions for the sulphuric acid-uranium - tertiary amine equilibrium. Strip solution containing up to 125 g/L U3O8 is obtained. This new process was developed to ensure that the effluents met environmental objectives, and to permit the continued use of the existing solvent extraction circuit for uranium recovery from a new ore body, the Collins Bay B-Zone deposit. The process provided substantial technical advantages over other stripping alternatives and substantial economic advantage over the LAMIX ion exchange process. Plant operations have confirmed initial mini-pilot plant and large scale pilot plant operations. Overall results are better than the design standards for the process. Current operations and possible future improvements are reviewed.