Arsenic incorporation into FeS2 pyrite and its influence on dissolution: A DFT study

Marc Blanchard, Maria Alfredsson, John Brodholt, Kate Wright, C. Richard A. Catlow

Research output: Contribution to journalArticle

98 Citations (Scopus)

Abstract

FeS2 pyrite can incorporate large amounts of arsenic (up to ca. 10 wt%) 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.

Original languageEnglish
Pages (from-to)624-630
Number of pages7
JournalGeochimica et Cosmochimica Acta
Volume71
Issue number3
DOIs
Publication statusPublished - 1 Feb 2007
Externally publishedYes

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