Simultaneous leaching of uranium, 230Th, and 226Ra from Saskatchewan ores by nitric and hydrochloric acids

Abstract

High-grade uranium ores of Cluff Lake and Key Lake mines from the province of Saskatchewan in Canada are treated with nitric and hydrochloric acids with the objective of leaching 230Th and 226Ra simultaneously with uranium to produce environmentally safe mill tailings. It is found that optimum conditions for uranium leaching are 50°C, 4 h, 30% solids in leach slurry and an acid concentration of 1 mol/L for HNO3 for both the ores. In the case of HCl, a 3 mol/L acid concentration is needed and addition of an oxidant is required because otherwise 230Th and 226Ra extractions remain poor.