Investigation of intermediate sulfur species during pyrite oxidation in the presence and absence of Acidithiobacillus ferrooxidans
Investigation of intermediate sulfur species during pyrite oxidation in the presence and absence of Acidithiobacillus ferrooxidans
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在存在和不存在氧化亚铁硫杆菌的情况下黄铁矿氧化过程中中间硫物种的研究
DOI：
10.1016/j.hydromet.2016.11.001
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发表时间：
2017-01-01
期刊：
影响因子：
4.7
通讯作者：
Dang, Zhi
中科院分区：
文献类型：
--
作者：
Tu, Zhihong;Guo, Chuling;Dang, Zhi
一段时间以来，黄铁矿化学和生物氧化过程中的中间硫物种一直是争论的焦点，特别是氧化过程中是否形成元素硫(S-0)和连多硫酸盐(SnO62-)的问题。氧化亚铁硫杆菌(A.ferrooxidans)是最常见的硫氧化细菌菌株之一，已被证明能显着加速黄铁矿的氧化。在这项研究中，通过采用不同的分析技术对有和没有氧化亚铁菌存在的情况下黄铁矿氧化的中间产物进行了比较；即高效液相色谱（HPLC）、X射线粉末衍射（XRD）、X射线光电子能谱（XPS）和带有能量色散谱仪（EDS）的扫描电子显微镜（SEM）。 HPLC结果表明，在氧化亚铁菌存在的情况下，黄铁矿氧化过程中S-0、S3O62-、S4O62-、S6O62-和SA的浓度增加。通过 XRD 和 XPS 还检测到次生矿物黄钾铁矾 (KFe3(SO4)(2)(OH)(6)) 和氧化氢氧化铁 (III) (FeOOH)。在没有氧化亚铁菌的情况下，S-0 也与 S3O62-、S4O62- 和 S5O62- 一起形成，但在实验结束时仅以非常低的浓度形成。 SEM显微照片进一步显示，黄铁矿被氧化亚铁菌严重侵蚀，一些球状颗粒覆盖在黄铁矿残渣的表面。根据 EDS 分析，这些颗粒很可能是 KFe3(SO4)(2)(OH)(6)。本研究定量证实了黄铁矿氧化过程中中间产物S-0和SnO62-的存在，这些信息加深了我们对黄铁矿氧化机理的理解。 (C) 2016 Elsevier B.V. 保留所有权利。
The intermediate sulfur species of pyrite chemical and biological oxidation have been the subject of controversy for some time, especially the question of whether or not elemental sulfur (S-0) and polythionates (SnO62-) are formed during the oxidation process.Acidithiobacillus ferrooxidans (A. ferrooxidans), one of the most common sulfur -oxidizing bacterial strains, has been shown to remarkably accelerate pyrite oxidation. In this study, the intermediate products of pyrite oxidation with and without A. ferrooxidans present were compared by employing different analytical techniques; i.e., high performance liquid chromatography (HPLC), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS). The HPLC results showed that the concentrations of S-0, S3O62-, S4O62-, S6O62- and SA increased during pyrite oxidation process in the presence of A. ferrooxidans. Secondary minerals jarosite (KFe3(SO4)(2)(OH)(6)) and iron(III) oxide-hydroxide (FeOOH) were also detected by XRD and XPS. Without A. ferrooxidans, S-0 was also formed and along with S3O62-, S4O62- and S5O62- but only at very low concentrations at the end of the experiment. SEM micrographs further revealed that the pyrite was severely eroded by A. ferrooxidans and some spheroidal particles covered the surfaces of pyrite residues. These particles are most likely to be KFe3(SO4)(2)(OH)(6) based on EDS analysis. The present study has quantitatively confirmed the presence of intermediate products of S-0 and SnO62- during pyrite oxidation, information that deepens our understanding of the mechanism of pyrite oxidation. (C) 2016 Elsevier B.V. All rights reserved.