Characterization Of The Leaching Properties Of A Uranium Leaching Pulp

This work was conducted to characterize the leaching behaviour of a uranium-containing pulp from a South African gold operation, with the objective of identifying operating parameters that could increase uranium extraction in the existing circuit. Batch leach tests in dilute sulphuric acid were used to study the effects of leaching time and oxidant (MnO₂) concentration under controlled conditions, including a high liquid-to-solids ratio and added ferrous sulphate. The results showed that relatively high uranium extraction can be achieved even at room temperature, and that most of the economically significant leaching is completed within about 25 hours. Increasing the MnO₂ concentration substantially increased both the rate and extent of uranium dissolution, mainly by raising the pulp potential to more oxidizing values. The study indicates that maintaining higher oxidant levels and oxidizing conditions could be a more effective strategy than raising temperature, and may also provide downstream benefits such as improved passivation of stainless steel elution columns and more effective deactivation of iron species prior to cyanidation.