Abstract:The effects of initial sulfuric acid concentration and type of acidification media on acidification stage of uranium bioleaching were studied in laboratory through column leaching experiment. The results show that with the same initial concentration of sulfuric acid, the tail liquid acidification has a shorter time, less acid consumption and less leaching amount of cumulative net iron compare to the tap water acidification, and both have the same uranium leaching rate. With an increases of initial sulfuric acid in tail liquid, acidification time is shortened, leaching amount of cumulative net iron increases, both cumulative uranium leaching rate and sulfuric acid consumption rate rise. The optimum acidification conditions include 40 g/L of initial sulfuric acid and medium of tail liquid.