Isopiestic Investigation of the Systems FeCl₂–(Na, K, Mg, Ca)Cl _n –H₂O at 298.15 K

Abstract

Isopiestic measurements were performed in aqueous FeCl2-solutions and in ternary systems of the type FeCl2–MCln–H2O (M = Na, K, Mg, Ca). Numeric data for water-isoactivity lines are presented and pertinent osmotic coefficients are calculated. The obtained data were recalculated using Pitzer’s equations. Pertinent parameters are given.

Solubility Model for Ferrous Iron Hydroxide, Hibbingite, Siderite, and Chukanovite in High Saline Solutions of Sodium Chloride, Sodium Sulfate, and Sodium Carbonate

“…The values in Moog et al are valid for ionic strength up to 6 molal. Our experiments covered ionic strength up to 5 molal; therefore, it is appropriate to rederive those thermodynamic data that had been derived in Nemer et al using the Pitzer interaction parameters for the pair of Fe +2 /Cl – and the triplet of Fe +2 /Na + /Cl – reported in Moog et al Rederivations are illustrated in Figure S1. The newly derived thermodynamic data in Figure S1, i.e., two log K values for Fe­(OH) 2 (s) and Fe 2 Cl­(OH) 3 (s), do not differ considerably from those originally derived in Nemer et al (Table and Figure S1).…”

“…Moog et al reported a set of Pitzer interaction parameters for the same pair, Fe +2 /Cl – , as well as the θ parameters for the species pair Na + /Fe +2 and the ψ parameter for the species triplet Fe +2 /Na + /Cl – from isopiestic measurements (Table ). The values in Moog et al are valid for ionic strength up to 6 molal.…”

“…Moog et al reported a set of Pitzer interaction parameters for the same pair, Fe +2 /Cl – , as well as the θ parameters for the species pair Na + /Fe +2 and the ψ parameter for the species triplet Fe +2 /Na + /Cl – from isopiestic measurements (Table ). The values in Moog et al are valid for ionic strength up to 6 molal. Our experiments covered ionic strength up to 5 molal; therefore, it is appropriate to rederive those thermodynamic data that had been derived in Nemer et al using the Pitzer interaction parameters for the pair of Fe +2 /Cl – and the triplet of Fe +2 /Na + /Cl – reported in Moog et al Rederivations are illustrated in Figure S1.…”

“…The newly derived thermodynamic data in Figure S1, i.e., two log K values for Fe­(OH) 2 (s) and Fe 2 Cl­(OH) 3 (s), do not differ considerably from those originally derived in Nemer et al (Table and Figure S1). This process of rederivation, however, is necessary to maintain the internal consistency of our final database because the values by Moog et al will be used for the series of our data analyses, including this paper. Note that the content of Figure S1 is not yet the conclusion of this paper because the log K for the Fe­(OH) 2 (s) in Figure S1, i.e., 12.83, was determined without considering the experimental data in Table (Figures and ), where the Fe­(OH) 2 (s), common to the experimental data in Table , was assigned to be the solubility limiting phase.…”

Application of low-temperature microthermometric data for interpreting multicomponent fluid inclusion compositions

“…The parameterizations used by FREZCHEM include ion interaction parameters from Spencer et al (1990) for the system H 2 O-NaCl-KCl-CaCl 2 -MgCl 2 . There are two independent sets of ion interactions parameters involving ferrous iron from Marion et al (2003), based on an earlier study of Ptacek (1992), and from Moog et al (2004), the former including ferrous chloride hydrate minerals. The analogous parameters for ferric iron were added to the dataset by , based in part on the earlier study of Christov (2004).…”