Partitioning metallic liquid composition

Figure 9 Comparison of In D (calculated) versus In D (measured) with data for cobalt n = 207) and tungsten n = 109), and using oxide-component-based compositional terms. Open symbols are 0.1 MPa experiments, and solid symbols are higher-pressure experiments. Dashed lines are 2cr errors on the regressions. The number of experiments used in the regression is indicated as n. M/LS refers to metal/liquid silicate for the partition coefficients, and includes experiments that have solid metal or liquid metal (source Righter and Drake, 1999).

Hillgren V. J., Drake M. J., and Rubie D. C. (1996) High pressure and higji temperature metal/siUcate partitioning of siderophile elements the importance of silicate liquid composition. Geochim. Cosmochim. Acta 60, 2257-2263. 

Fig. 7. (a) Impurity elements are rejected into the liquid between the dendritic solidification fronts, (b) Corresponding impurity concentration profiles. CQ, weld metal composition k, impurity partitioning coefficient in the liquid C, maximum impurity solid solubility C, eutectic composition at grain... 

Metal concentrations and metal activities in the pore water are dependent upon both the metal concentration in the solid phase and the composition of both the solid and the liquid phase. In matrix extrapolation, and with emphasis on the pore water exposure route, it is therefore of great practical importance to have a quantitative understanding of the distribution of heavy metals over the solid phase and the pore water. A relatively simple approach for calculating the distribution of heavy metals in soils is the equilibrium-partitioning (EP) concept (Shea 1988 van der Kooij et al. 1991). The EP concept assumes that chemical concentrations among environmental compartments are at equilibrium and that the partitioning of metals among environmental compartments can be predicted based on partition coefficients. The partition coefficient, Kp, used to calculate the distribution of heavy metals over solid phase and pore water is defined as... 

The function of lESs with a hquid membrane can hence be ascribed to a variety of different chemical reactions and interaction equilibria. The extraction (partition) equilibriiun is fundamental. Further contributions can come from complex formation, adsorption and ion exchange. Identical relationships are vahd for voltage formation between metallic and electrolytic phases, as well as for phase boundaries discussed here. The potential which can be measured between the reference electrode and the terminal of an ISE with liquid membrane obeys the Nernst equation. A large variety of liquid-membrane compositions results from the large number of chemical phenomena participating in interface processes. Very important is the fact that ligands may be tailor-made to interact specifically with certain cations. 

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