Arsenic incorporation into FeS2 pyrite and its influence on dissolution: A DFT study
Arsenic incorporation into FeS2 pyrite and its influence on dissolution: A DFT study
复制标题
DOI：
10.1016/j.gca.2006.09.021
复制
发表时间：
2007-02
影响因子：
5
通讯作者：
M. Blanchard;M. Alfredsson;J. Brodholt;K. Wright;C. Catlow
中科院分区：
文献类型：
--
作者：
M. Blanchard;M. Alfredsson;J. Brodholt;K. Wright;C. Catlow
FeS2黄铁矿可以结合大量的砷（高达约。10wt%），因此对这种有毒准金属的流动性具有强烈的影响。专注于最低的砷浓度的掺入发生在固溶体中，所涉及的取代机制进行了研究，通过假设简单的掺入反应在氧化和还原条件。通过密度泛函理论（DFT）计算的解决方案的能量进行了计算，我们预测，形成的AsS二价阴离子基团是最积极有利的机制。结果还表明，砷的存在将加速溶解，从而产生酸排水，当晶体溶解在氧化条件下。
FeS2pyrite can incorporate large amounts of arsenic (up to ca. 10wt%) and hence has a strong impact on the mobility of this toxic metalloid. Focussing on the lowest arsenic concentrations for which the incorporation occurs in solid solution, the substitution mechanisms involved have been investigated by assuming simple incorporation reactions in both oxidising and reducing conditions. The solution energies were calculated by Density Functional Theory (DFT) calculations and we predict that the formation of AsS dianion groups is the most energetically favourable mechanism. The results also suggest that the presence of arsenic will accelerate the dissolution and thus the generation of acid drainage, when the crystal dissolves in oxidising conditions.