黑曲霉两步法与化学氧化联合浸出花岗岩铀矿石

为了高效浸出花岗岩型铀矿石中的铀，采用黑曲霉两步法和化学氧化联合浸出，研究预培养时间、浸出时间和不同氧化剂及其用量对浸铀效果的影响。结果表明：黑曲霉两步法浸出时，采用预培养36 h的黑曲霉浸铀，浸出时间为72 h时，铀浸出率最高，为59.34%，随着预培养时间和浸出时间的延长，铀浸出率显著下降。加入MnO₂、NaClO₃和H₂O₂三种氧化剂对铀浸出率均有不同程度的提高，其中加入2.5%（与矿石质量比）的MnO₂时，浸铀效果最佳，铀浸出率最高可达74.09%，与未加氧化剂相比，铀浸出率提高了14.8%。

Two-Step Process of Aspergillus Niger-Chemical Oxidation Joint Leaching of Granite Uranium Ore

To high-efficiently recover uranium from granite-type uranium ore,a two-step process by Aspergillus niger coupling with chemical oxidants was applied to investigate the effects of pre-culture time,leaching time,oxidant type and dosage on uranium extraction.The results show that the highest uranium recovery of 59.34%is achieved in 36 hours of pre-culture and 72 hours of leaching time in the two-step process by Aspergillus niger.The uranium recovery decreases significantly with the increase of pre-culture time and leaching time.Addition of each of MnO 2,NaClO₃ and H₂O₂ results in an increase in uranium recovery.At a dosage of 2.5%MnO 2 by weight of uranium ore,the highest uranium recovery reaches to 74.09%,having an increase of 14.8%compared with the absence of the oxidant.