Bioleaching of Uranium Ore Containing Fluorite Using Acidithiobacillus ferrivoran, Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum

Abstract

Abstract. The results of MLA automated quantitative mineralogy system indicated the uranium ore used in this study was mainly composed of pitchblende (0.47%), quartz (64.91%), fluorite (2.18%) and pyrite (0.44%). The existence of fluorine-containing minerals plays a strong inhibition role of bacterial activity in the bioleaching process. The chemical characteristics showed that the content of U ( ) Ⅳ (0.18%)was significantly higher than that of U () Ⅵ , and the U () Ⅳ / U () Ⅵ ratio was 4.5. It is difficult to dissolve with sulfuric acid due to relatively higher U () Ⅳ in this uranium ore. The fluoride-tolerance mixed microbes were used for bioleaching of uranium, and the bioleaching and acid leaching experiments of fluoride-containing uranium ore were investigated in column reactor. The uranium extration rate of bioleaching column reached 72% in 38 days, using bioleaching have obvious advantages compare to conventional acid leaching (65%).