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研究砂岩型铀矿床中本源嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,At.f)、嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans,At.t)对黄铁矿及铀矿浸出的协同作用。采用富集培养法、无机盐硅酸钠平板法对砂岩型铀矿中的硫杆菌分离纯化,通过分析菌株的形态学特征、生理生化结果及16S r DNA序列确定菌株的系统发育地位,并利用摇瓶培养法设计浸矿试验,向黄铁矿浸出体系中分别加入分离纯化的At.f、At.t及混合的At.f和At.t,检测p H值、氧化还原电位值(Eh值)的变化,浸矿40 d,测定浸矿体系的总铁离子浓度和硫酸根离子浓度,并分析黄铁矿矿渣表面形态及成分。根据黄铁矿的浸出结果,设计铀矿浸出试验,浸矿40 d,测定浸出体系中的p H值、Eh值、总铁离子浓度、硫酸根离子浓度等参数并计算四价铀的浸出率。结果表明,分离的两株优势菌中SW-2鉴定为嗜酸性氧化亚铁硫杆菌(At.f),SW-3鉴定为嗜酸性氧化硫硫杆菌(At.t)。At.f、At.t浸出黄铁矿和铀矿时存在协同作用,At.f为浸矿体系的强氧化剂,主要将Fe~(2+)氧化成Fe~(3+),Fe~(3+)将UO_2氧化成可溶性的UO_(2~(2+));At.t可为浸矿体系提供酸性环境;At.f:At.t=5:1试验组对黄铁矿和铀矿的浸矿效果最好,四价铀的浸出率为55.60%,黄铁矿矿渣表面形态显示细菌对黄铁矿存在直接的氧化作用;At.f、At.t高效浸出黄铁矿的菌量比例对以黄铁矿为伴生矿的铀矿的细菌浸出也具有明显的促进作用,研究结果可以为工业微生物浸铀时提供一定的支持并为以黄铁矿为伴生矿的其他矿物的微生物浸出提供参考。
To study the synergistic effect of Acidithiobacillus ferrooxidans (At.f) and Acidithiobacillus thiooxidans (At.t) on the leaching of pyrite and uranium from sandstone-type uranium deposits. The enrichment culture method and inorganic sodium silicate plate method were used to separate and purify Thiobacillus from sandstone-type uranium mine. The morphological characteristics, physiological and biochemical results and 16S rDNA sequence were used to determine the phylogenetic position of the strain. The shake-flask culture method was used to design the immersion test. The isolated and purified At.f, At.t and the mixed At.f and At.t were added to the pyrite leaching system respectively to detect the values of p H, redox potential (Eh Value), leaching ore for 40 days, measuring the total iron ion concentration and sulfate ion concentration in the leaching ore system, and analyzing the surface morphology and composition of the pyrite slag. According to the leaching results of pyrite, the leaching experiment of uranium ore was designed. After leaching for 40 days, the p H value, Eh value, total iron ion concentration and sulfate ion concentration in the leaching system were measured and the leaching rate of uranium . The results showed that SW-2 was identified as Acidophilic Thiobacillus ferrooxidans (At.f) and SW-3 as Acidophilic Thiobacillus thiooxidans (At.t) in two isolates. At.f, At.t has a synergistic effect when leaching pyrite and uranium ore. At.f is a strong oxidizer of the ore leaching system and mainly oxidizes Fe2 + to Fe3 +, Fe ~ 3+) oxidizes UO_2 to soluble UO_ (2 ~ (2 +)); At.t can provide an acidic environment for the leaching system; At.f: At.t = 5: The ore leaching is the best, the leaching rate of quaternary uranium is 55.60%, the surface morphology of pyrite slag shows the direct oxidation of bacteria to pyrite; At.f, At.t efficient leaching of pyrite The results also provide some support for the leaching of uranium from industrial microorganisms, and provide some support for the microbial leaching of pyrite with other minerals associated with ore Leaching for reference.