有色金属(冶炼部分)

Acidiphilium multivorum（简称A.m）菌具有铁还原性和硫氧化性，这对铀矿生物浸出具有重要的启示作用。研究表明，铀矿生物浸出中Acidithiobacillus ferrooxidans（简称A.f）菌与A.m菌主要表现为铁循环和碳循环的协同作用，以某硬岩型铀矿为浸出材料，开展A.f菌与A.m菌协同浸铀时，A.m菌的铁还原作用协同A.f菌的铁氧化作用，促进浸出体系中铁的循环，铁循环使得A.f与A.m菌获得了更多和更长久的能源物质，促进了它们的生长繁殖；A.f菌在浸铀过程中，会产生有机物，这些有机物会限制A.f菌的生长繁殖，但A.m菌在铁还原过程中能利用这些有机物进行异养生长，因此可解除其对A.f菌生长繁殖的抑制作用，同时产生CO2，能进一步为A.f菌提供了无机碳源。此外，A.m菌还能利用单质硫获得能源，促进单质硫氧化为硫酸，硫酸能分解铀矿石表面的黄钾铁矾，缓解铀矿石表面钝化膜的形成，最终提升铀的浸出效率。

Acidiphilium multivorum(A.m) has the ability of iron reduction and sulfur oxidation,which has important implications for uranium bioleaching. The results show that the synergistic mechanism of Acidithiobacillus ferrooxidans(A.f) and A.m bacteria in uranium bioleaching is mainly manifested as the synergistic effect of iron cycle and carbon cycle. When a hard rock-type uranium ore is used as leaching material to carry out the synergistic leaching of uranium by A.f and A.m bacteria, the iron reduction of A.m bacteria and the iron oxidation of A.f bacteria promote the iron cycle in the leaching system. The iron cycle makes A.f and A.m bacteria obtain more and longer energy substances, which promotes their growth and reproduction. In the process of leaching uranium,A.f bacteria will produce organic matter, which will limit the growth and reproduction of A.f bacteria, but A.m bacteria can use these organic matter for heterotrophic growth in the process of iron reduction, so it can relieve its inhibition on the growth and reproduction of A.f bacteria, and produce CO2, which can further provide inorganic carbon source for A.f bacteria. In addition, A.m can also use elemental sulfur to obtain energy and promote the oxidation of elemental sulfur to sulfuric acid. Sulfuric acid can decompose jarosite on the surface of uranium ore,alleviate the formation of passivation film on the surface of uranium ore, and ultimately improve the leaching efficiency of uranium. The addition of A.m bacteria improved the uranium leaching efficiency of A.f bacteria. In this experiment, the uranium leaching of pure A.f group is basically completed within 48 hours, and the leaching rate of uranium is 87. 75%. The leaching results of the bacteria group with A.f and A.m of 10∶1 are not much different from those of the pure A.f bacteria group before 12 hours,but the leaching of uranium in the bacteria group with A.f and A.m of 10∶1 is accelerated after 12 hours. The uranium is basically leached in 60 hours, and the leaching rate is as high as 98%. The leaching efficiency of the bacteria group with A.f and A.m of 10∶1 is 11. 68% higher than that of the pure A.f bacteria group. In summary, A.f has iron-sulfur oxidation, and A.m has iron reduction and sulfur oxidation. The iron reduction of A.m bacteria can be used to cooperate with the iron oxidation of A.f bacteria to promote the circulation of iron in the bioleaching system. The iron circulation makes A.f and A.m bacteria obtain longer energy substances.