Bioleaching

Uranium

Bioleaching of non-sulfidic ores such as pitchblende also uses ferric iron as an oxidant (e.g., UO₂ + 2 Fe ==> UO₂ + 2 Fe). In this case, the purpose of the bacterial step is the regeneration of Fe. Sulfidic iron ores can be added to speed up the process and provide a source of iron. Bioleaching of non-sulfidic ores by layering of waste sulfides and elemental sulfur, colonized by Acidithiobacillus spp., has been demonstrated, which provides a strategy for accelerated leaching of materials that do not contain sulfide minerals.