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[SGC50-05] Partitioning behavior of elements between metal and sulfide melt
Keywords:element partitioning, metal, sulfide, high pressure
We synthesized Fe-Ni(95:5) alloy doped with 14 trace elements (Co, Cu, Ge, Mo, Ru, Ph, Pd, W, Re, Os Ir, Pt, Au, Pb) in approximately 150 ppm, by arc-melting method. A small chip of this alloy and a small amount of FeS powder were packed in the MgO capsule, and high pressure melting experiments were performed using Kawai-type multi-anvil press installed at Tokyo Institute of Technology. Quenched samples were polished and major element compositions were measured by EPMA. Trace element abundances were determined by LA-ICP-MS installed at Kyoto University.
The observed partition coefficients in the present experiments were generally in agreement with the previous works, and indicating strong dependences to sulfur content in liquid phase. When we accept that partition coefficients are mainly controlled by chemical affinity of elements, then size dependence of partition coefficients must be found in sulfur free system, which includes no chemical affinity effects on partition coefficients. Although we have no data for such pure metallic system, partitioning behavior in the pure metal system can be predicted from the observed sulfur dependence in partitioning behaviors. It was found that the differences in partition coefficients between elements become smaller with sulfur content of liquid phase decreases. This means that partition coefficients in pure metal system may show similar values, even if in large sized elements, such as Au or W.
Blundy & Wood(1994), Nature 372, 452-454.
Clementi et al.(1967), J. Chem. Phys., 47, 1300-1307.
Stewart et al.(2009), Earth Planet. Sci. Lett. 284, 302-309.
Van Orman et al. 2008), Earth Planet. Sci. Lett. 274, 250-257.