Role of Fe/S ratios in the enhancement of uranium bioleaching from a complex uranium ore by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans consortium  

Fe/S比在氧化亚铁硫杆菌与氧化硫硫杆菌混合浸出复杂铀矿石过程中的强化效应

作　　者：SUN Jing MA Jin-fang LI Qian LI Guang-yue SHI Wen-ge YANG Yu HU Peng-fei GUO Zhi-min 孙静;马晋芳;李乾;李广悦;史文革;杨雨;胡鹏飞;郭志敏(Key Discipline Laboratory for National Defence of Biotechnology in Uranium Mining and Hydrometallurgy(University of South China),Hengyang 421001,China;School of Resources&Environment and Safety Engineering,University of South China,Hengyang 421001,China)

机构地区：[1]Key Discipline Laboratory for National Defence of Biotechnology in Uranium Mining and Hydrometallurgy(University of South China),Hengyang 421001,China [2]School of Resources&Environment and Safety Engineering,University of South China,Hengyang 421001,China

出　　处：《Journal of Central South University》2022年第12期3858-3869,共12页中南大学学报（英文版）

基　　金：Project(51804165) supported by the National Natural Science Foundation of China;Project(2018JJ3441) supported by the Natural Science Foundation of Hunan Province,China。

摘　　要：The role of Fe/S ratios(ω, g/g) in the uranium bioleaching from a complex uranium ore by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans consortium was investigated. The results showed good uranium extraction with over 90% at the Fe/S ratio of 5:0.5, 5:1 and 5:5, while poor extraction(<46%) at the Fe/S ratio of 5:0 and 5:10.Furthermore, the bacterial community analysis based on species-specific gyrB numbers indicated that, absent sulfur or excessive sulfur would be not conducive to the synergistic growth for A. ferrooxidans and A. thiooxidans, and then not conducive to the uranium dissolution. Meanwhile, the sulfur-oxidizers could play an important role in the process of uranium synergistic bioleaching by mixed bacterial consortia. Additionally, the characteristics of mineral residue was detected by SEM-EDS. The results showed appropriate sulfur dosage would change the structure and improve the porosity of passivation substance. Lastly, the uranium dissolution kinetics and biochemical reaction mechanism was analyzed. It indicated that the biochemical reaction coupling iron and sulfur had a pleiotropic effect on the uranium dissolution from the ore particles, appropriate Fe/S ratio is the key factor for uranium bioleaching by chemoautotrophic acidophiles.研究了嗜酸氧化亚铁硫杆菌及氧化硫硫杆菌混合浸出复杂铀矿石过程中Fe/S比的影响。结果表明,当Fe/S为5:0.5,5:1,5:5时,铀浸出率较高,达90%;当Fe/S为5:0,5:10时,铀浸出率低于46%。此外,基于物种特异性基因gyrB的细菌群落分析表明,缺硫或过量硫都不利于氧化亚铁硫杆菌和氧化硫硫杆菌的协同生长,进而不利于铀的浸出,且硫氧化细菌在混合菌群协同浸铀过程中发挥着不可忽视的作用。SEM-EDS矿渣表征结果表明,适当的硫用量可以改变钝化物的结构,提高其孔隙率。分析了铀的溶解动力学和生化反应机理,结果表明,铁与硫耦合的生化反应对矿石颗粒中铀的溶解有多方面的化学效应,Fe/S比是调控铁硫氧化细菌菌混合浸铀的最关键因素之一。

关 键 词：uranium bioleaching Fe/S ratio community dynamics dissolution kinetics reaction mechanism 

分 类 号：TD868[矿业工程—金属矿开采]