Leaching of Zinc Sulfide by Thiobacillus ferrooxidans: Bacterial Oxidation of the Sulfur Product Layer Increases the Rate of Zinc Sulfide Dissolution at High Concentrations of Ferrous Ions
Leaching of Zinc Sulfide by Thiobacillus ferrooxidans: Bacterial Oxidation of the Sulfur Product Layer Increases the Rate of Zinc Sulfide Dissolution at High Concentrations of Ferrous Ions
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DOI：
10.1128/aem.65.12.5285-5292.1999
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发表时间：
1999-12
影响因子：
4.4
通讯作者：
T. Fowler;F. Crundwell
中科院分区：
文献类型：
--
作者：
T. Fowler;F. Crundwell
摘要 本文报告了在相同条件下在溶液中使用和不使用氧化亚铁硫杆菌进行的浸出实验的结果。在高浓度亚铁离子条件下，有细菌的 ZnS 浸出程度明显高于无细菌的情况。化学浸出颗粒的表面上存在单质硫的多孔层，而细菌浸出颗粒的表面上不存在硫。使用收缩核心模型对数据的分析表明，ZnS 的化学浸出受到高浓度亚铁离子通过硫产物层的亚铁离子扩散的限制。数据分析表明，当存在细菌时，通过产品层的扩散不会限制溶解速率。这表明氧化亚铁杆菌氧化颗粒表面形成的硫的作用是消除亚铁离子扩散的障碍。
ABSTRACT This paper reports the results of leaching experiments conducted with and without Thiobacillus ferrooxidans at the same conditions in solution. The extent of leaching of ZnS with bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, while no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T. ferrooxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions.