| 酸性条件下黄铁矿氧化机制的研究 |
| 摘要点击 1656 全文点击 1169 投稿时间：2012-01-05 修订日期：2012-03-12 |
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| 中文关键词 黄铁矿 电化学 循环伏安 极化曲线 氧化 |
| 英文关键词 pyrite electrochemistry cyclic voltammetry polarization curve oxidation |
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| 中文摘要 |
| 以黄铁矿粉末制备成的碳糊电极为工作电极,利用循环伏安曲线和极化曲线等电化学手段,对酸性条件下黄铁矿的氧化过程和机制进行了研究. 结果表明,黄铁矿的氧化主要包括以下两个过程:首先,黄铁矿(FeS2)矿物晶格中的Fe2+溶出而被氧化为Fe3+,此过程会伴随有如硫单质、缺铁硫化物(Fe1-xS2)和多硫化物(FeSn)等氧化中间产物的生成,覆盖在黄铁矿的表面而形成一层钝化膜,阻碍了其氧化溶解过程; 接着,黄铁矿表面的钝化膜被进一步氧化为可溶性的SO42-. 在酸性条件下,黄铁矿氧化反应的最终产物为Fe3+和SO42-. 另外,在所研究的酸度范围内,随着H2SO4溶液浓度的增大,体系的开路电位和腐蚀电位均正移,氧化和还原的峰电流值升高,腐蚀电流增大,说明增加体系的酸度会促进黄铁矿的氧化过程. |
| 英文摘要 |
| The mechanism of pyrite oxidation in acidic solutions was investigated by electrochemical analysis methods, such as open-circuit potential, cyclic voltammetry, Tafel polarization curve and anodic polarization curve, using a pyrite-carbon paste electrode as working electrode. The results showed that the oxidation process of pyrite in acidic solutions was via a two-step reaction: the first step was the dissolution of iron moiety and formation of a passivation film composed of elemental sulphur,metal-deficient sulfide and polysulfide; the second step was the further oxidation of these intermediate products to SO42-. The final reaction products of pyrite oxidation were Fe3+ and SO42- in acidic solutions. In addition, the open-circuit potential and corrosion potential were positively shifted, the peak current and the corrosion current were increased with the increase in concentration of H2SO4 solutions. This indicated that increased acidity of the system was advantageous to the oxidation of pyrite. |
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