相山铀矿混合铀矿石微生物浸出工艺试验及浸出机理初探

发布时间：2018-07-10 06:04

本文选题：微生物浸铀 + 喷淋强度　；参考：《东华理工大学》2017年硕士论文

【摘要】：与传统方法相比微生物浸铀技术具有投资少、酸耗低、环境污染小、工艺流程简单等优点,越来越受到研究者的青睐。本文研究了不同因素对铀矿石浸出效果的影响,从喷淋强度、细菌接种量和铁浓度等方面分析了铀矿石的浸出作用规律和浸出效果,初步探讨了溶浸液与铀矿石的作用机理。具体研究内容与结果如下:喷淋强度试验表明,在浸出第108天,5%、10%、15%、20%、25%喷淋强度铀累计浸出率分别是80.97%、81.54%、91.40%、89.27%,81.83%,渣计浸出率分别是82.2%、88.5%、90.9%、88.35%、87.55%,累计耗酸率分别是8.58%、10.42%、11.13%、12.11%、13.27%。考虑酸浸周期、累计耗酸率、铀累计浸出率和渣计浸出率等因素,15%喷淋强度铀浸出效果最优。细菌接种量试验表明,浸出铀浓度和铀浸出率随细菌接种量的增多而升高,但30%细菌接种量浸出铀浓度和铀浸出率增加幅度开始减小。因此,适度提高细菌接种量,有利于铀矿石的浸出。铁浓度试验表明,9g/LFe~(2+)浸出铀浓度和铀浸出率低于5g/LFe~(2+)高于3g/LFe~(2+),5g/LFe~(2+)细菌活性最好,浸出效果最佳。9g/LFe~(3+)浸出铀浓度和铀浸出率与5g/LFe~(3+)相差不大。Fe~(3+)离子浓度越高,细菌活性越低,不利于细菌与矿石相互作用,Fe~(3+)离子浓度不应超过5g/L。选取浸出前后试验矿样进行扫描电镜、能谱分析以及XRD衍射分析。溶浸液与铀矿石作用机理初探表明,原矿样表面平整光滑、结构完整、无裂隙凹坑,主要含有K、Ca、Si、Na、Al、O等元素,石英(SiO_2)、钠长石(NaAlSi3O8)、钙长石(CaAl2Si2O8)、斜长石((K,Na)AlSi3O8)、钾长石(KAlSi3O8)等矿物。在溶浸液作用下,矿石表面出现不同程度的腐蚀破坏,元素组分发生明显变化,并生成了造成矿石板结的石膏(CaSO4·2H2O)和黄钾铁钒(KFe_3(SO_4)_2(OH)6)沉淀物。
[Abstract]:Compared with traditional methods, microbial uranium leaching technology has many advantages, such as less investment, less acid consumption, less environmental pollution and simple technological process. In this paper, the influence of different factors on the leaching effect of uranium ore is studied. The leaching law and leaching effect of uranium ore are analyzed from the aspects of spray strength, inoculation amount of bacteria and concentration of iron, and the mechanism of action between leaching solution and uranium ore is preliminarily discussed. The specific research contents and results are as follows: the experimental results show that on the 108th day of leaching, the accumulative leaching rate of uranium is 80.977,81.540.91.400.20% and 25%. The cumulative acid consumption rate is 8.588.4210.4210.4212.1312.1112.1312.1112.1312.1112.1312.1112.1312.1112.1312.1312.1312.1312.1112.1312.1312.1312.1112.1312.1312.1312.1112.1312.1312.1312.1312.1113.275.The cumulative acid consumption rate is 8.580.10.4210.4212.1312.1113.2755.The leaching rate of the slag meter is 82.288.58.35 / 88.357.555.The cumulative acid consumption rate is 8.58510.4210.4212.1312.1112.1113.27. Considering the acid leaching period, the accumulative acid consumption rate, the uranium accumulative leaching rate and the slag leaching rate, the effect of uranium leaching with 15% spray strength is the best. Bacterial inoculation test showed that the concentration of uranium and the leaching rate of uranium increased with the increase of bacterial inoculation, but the concentration of uranium and the rate of leaching of uranium by 30% bacteria began to decrease. Therefore, a moderate increase in bacterial inoculation is beneficial to the leaching of uranium ores. The results of iron concentration test showed that the concentration of uranium and the leaching rate of uranium were lower than 5 g / L Fe ~ (2) and higher than 3 g / L L Fe ~ (2) > 3 g / L Fe ~ (2). The bacteria activity was the best, and the leaching effect was the best. The concentration of uranium and the leaching rate of uranium were similar to that of 5 g / L LFe3. The higher the concentration of Fe3 ions, the lower the activity of bacteria. The Fe ~ (3) ion concentration should not exceed 5 g / L. The samples before and after leaching were selected for SEM, EDS and XRD analysis. The mechanism of interaction between leaching solution and uranium ore shows that the surface of the sample is smooth, the structure is intact and there are no fissure pits. It mainly contains minerals such as K _ (Ca-CaO), Na _ 2O _ 3, Sio _ 2, NaAlSi _ 3O _ 8, CaAl2Si _ 2O _ 8, K _ (AlSi _ 3O _ 8), K _ AlSi _ 3O _ 8 and so on. The results show that: (1) the surface of the sample is smooth, the structure is intact, and there are no fissure pits. The main minerals are quartz (SiO2), albite (NaAlSi3O8), CaAl2Si2O8, plagioclase (Knna) AlSi3O8, potassium feldspar (KAlSi3O8) and so on. Under the action of leaching solution, the surface of the ore was corroded to varying degrees, and the element composition changed obviously. The gypsum (CaSO _ 4 _ 2H _ 2O) and K _ FeS _ 3 (so _ 4) _ 2 (OH) _ 6) precipitates were formed, which resulted in the formation of gypsum (CaSO _ 4 _ 2H _ 2O) and K _ Fe _ 3 (so _ 4) _ 2 (OH) _ 6.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD958;TD925.5

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