Abstract
This paper explores the optimization of in-situ uranium leaching efficiency through the application of oxygen as an oxidizing agent in the lixiviant. With this objective in mind, geological characteristics of the target site were examined, followed by a series of laboratory and pilot-scale experiments. The resulting data were systematically processed and analyzed. The influence of sulfuric acid concentration on the degree of oxygen enrichment in the lixiviant was established. Laboratory tests on core samples from the uranium deposit revealed consistent relationships between uranium concentration in the pregnant solution, the oxidation states of iron (Fe2+ and Fe3+) in lixiviant, and the level of oxygen saturation. Comparative results of uranium content in the pregnant solution over time were obtained for both the conventional and oxygen-enriched technologies. Laboratory results demonstrated a 23.0% increase in uranium concentration in the pregnant solution using an oxygen-enriched lixiviant over the control solution, indicating a potential reduction in recovery time and final metal production costs. Pilot-scale tests at a uranium mine confirmed the positive effect of oxygen-enriched lixiviant on iron oxidation and uranium concentration in the pregnant solution. All pumping wells within the test block showed increased or stabilized uranium concentration upon connecting a special injection system for oxidation in injection wells surrounding the pumping wells, and decreased uranium concentration after system disconnection.