1、5700 汉字， 3300 单词， 1.7 万英文字符 出处： Umanskii A B, Klyushnikov A M. Bioleaching of low grade uranium ore containing pyrite using A. ferrooxidans, and A. thiooxidansJ. Journal of Radioanalytical & Nuclear Chemistry, 2013, 295(1):151-156. Bioleaching of low grade uranium ore containing pyrite using A. ferr
2、ooxidans and A. thiooxidans AB Umanskii， AM Klyushnikov Abstract: A process of uranium extraction from ore containing 3.1 % pyrite by bacterial leaching was investigated in shaken flasks during 90 days. The highest uranium recovery amounting to 85.1% was obtained using binary mixture of Acidithiobac
3、illus ferrooxidans and Acidithiobacillus thiooxidans that was exceeding results obtained by traditional acid leaching technique up to 27 %. High uranium recovery was founded to be due to the high degree of pyrite dissolution that can be readily achieved by bacterial leaching (up to 98.0 %). Keywords
4、： Uranium leaching； Bacterial leaching； Acidithiobacillus ferrooxidans； Acidithiobacillus thiooxidans Introduction Acid leaching is known to be predominant process for uranium recovery from ores, usually with sulfuric acid because its relatively low cost. Uranium that mostly presented in ores in tet
5、ravalent state must be oxidized to hexavalent state U(VI) before it can be dissolved. In acid leaching, the uranium oxidation reaction requires the presence of ferric ion, regardless of the reagent used as an oxidant, since that appears that the ferric ion actually oxidizes the uranium while the oxi
6、dant reagent oxidizes ferrous ion to ferric ion 1. So the dissolution of tetravalent uranium in sulfuric acid leaching system follows equation 2: UO2 +Fe2(SO4)3=UO2SO4 +2FeSO4 (1) Various oxidants such as MnO2, NaClO3, H2O2 are widely employed as a ferrous ion oxidant in uranium leaching processing 3. But these oxidants are very costly or cause very serious environmental pollution than sulfuric acid because of release of heavy metals to the environment. One more alter
