GEOC 105 |
| The interaction of FeS with various metals and metalloids is primarily facilitated by its extreme small crystallite size, atomic structure, and surface charge properties. The mechanisms for incorporation of minor and trace elements (i.e., impurities) in the initial FeS precipitate and during the subsequent transformation of FeS to pyrite (FeS2) are not entirely clear. These processes are important because incorporation of impurities in sedimentary FeS2, a relatively insoluble and thermodynamically stable mineral phase under reducing conditions, directly affects their geochemical cycling. A recent characterization of the initial FeS precipitate using synchrotron radiation and advanced XRD techniques indicates that this phase is nanocrystalline and has an atomic structure nearly identical to crystalline mackinawite. By conducting hydrothermal aging experiments in situ the structural transformation of FeS to FeS2 can be tracked to assess the effect and fate of impurities during these reactions. These experiments are carried out using new techniques developed to avoid compromising the reaction conditions.
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The Structure and Reactivity of Nanoparticles in the Environment
8:50 AM-11:55 AM, Wednesday, 13 September 2006 Moscone Center -- Room 262, Oral
Division of Geochemistry |
