PVTx properties of H2O–H2S fluid mixtures at elevated temperature and pressure based on new experimental data

An experimental study of Cobalt (II) complexation in Cl− and H2S-bearing hydrothermal solutions

“…The binary interaction parameters for the H 2 O-H 2 S system were taken from Zezin et al (2010). Additional details on these calculations are provided in Zezin et al (2010).…”

Differential alteration of basaltic lava flows and hyaloclastites in Icelandic hydrothermal systems

“…Aqueous activity coefficients were calculated by GEM-Selektor v.3 by using the extended Debye-Hückel equation consistent with SUPCRT98 data and HKF EoS, with the common ion size parameter equal to 0.372 nm and the third parameter b g equal to 0.064 (as for NaCl electrolyte). The stability and mixing in the non-ideal gaseous fluid were calculated using the Peng-Robinson-Stryjek-Vera (PRSV) multicomponent fluid model (Stryjek and Vera 1986;Zezin et al 2011).…”

The solubility of gold in H2O–H2S vapour at elevated temperature and pressure

“…Owing to the strongly non-ideal behaviour of H 2 O-H 2 S fluid mixtures resulting from the dipolar nature of molecules of water and hydrogen sulphide, Margules-type composition-dependent mixing rules (Anderko, 2000) and system-specific binary interaction parameters were employed to facilitate the calculation of pressure and the fugacity coefficients of components in the mixture (cf. Zezin et al, 2011). In contrast to H 2 O and H 2 S, the behaviour of gaseous gold and sulphur species was assumed to be ideal because of their very limited concentration in the gas phase compared to that of H 2 O andH 2 S. Accordingly, the partial pressures of Au and S were calculated from the ideal gas law, and the fugacities of Au and S species are considered equal to the corresponding partial pressures.…”

“…The experiments were conducted in the vapour-only region. Consequently, the composition of the fluid was restricted to ensure that the H 2 O-H 2 S gas mixtures did not saturate with liquid at the temperatures and pressures investigated (the equation of state and thermodynamic model developed by Zezin et al (2011) were used to estimate the conditions at which the vapour becomes saturated with liquid). The detection limit of the analytical method (INAA) did not permit measurements of the solubility of gold at low pressure and concentration of H 2 S (e.g., P < $100 bar and y H 2S ðgÞ <$0.4 at 300°C).…”

“…The values of the equilibrium constants K Si and K H 2 Sj , which are both T-and P-dependent constants, were calculated from the thermodynamic data of Mills (1974) and Suleimenov and Ha (1998), and the value for f H 2 S from the equation of state for H 2 O-H 2 S gas mixtures (Zezin et al, 2011). The total partial pressure of sulphur species was determined from the experimental data using the ideal gas law, P exp S ¼ N S RT V , where N S is the number of moles of sulphur lost from the ampoule during an experiment, R is the gas constant, T is the temperature, and V is the volume of the autoclave after subtraction of the volumes of log f , bar (5) and (6).…”