Mathematics – Logic
Scientific paper
Feb 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993gecoa..57..733j&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 57, Issue 4, pp.733-746
Mathematics
Logic
2
Scientific paper
Understanding the role of fluids in geological processes requires a knowledge of the mixing properties of common geological fluids. A technique for experimentally determining activity coefficients for H 2 O in fluid mixtures at pressures and temperatures accessible to the internally heated pressure vessel (10 kbar, 1100°C) is presented which uses a new f H 2 O buffer. The f H 2 O buffer involves the simultaneous control of f O 2 (with Ni / NiO ) and f H 2 (with a hydrogen membrane), thereby buffering f H 2 O (or equivalently, a H 2 O through the reaction H 2 + 1/2 O 2 = H 2 O . After quenching the run, the sample is analyzed to determine the X H 2 O and, thus, the activity-composition relation for H 2 O ( a H 2 O - X H 2 O ). Reversals are obtained by simultaneously running capsules loaded with low and high X H 2 O , thereby allowing the equilibrium X H 2 O to be approached from both directions. Several experimental problems encountered during this study and their implications for the precise control of f H 2 in hydrothermal experiments are discussed. Data were collected primarily in the H 2 O-CO 2 system at 2 kbars, 550-850°C, and at 4 kbars, 650°C. At those conditions, the H 2 O-CO 2 system generally shows small positive deviations from ideality. These results are in good agreement with the predictions of the MRK equation of state of (1977) at low T ( T = 550° C ) and are in good agreement with the predictions of the MRK equation of state of And (1981) at higher temperatures. At two conditions (2 kbar, 750°C; 4 kbar, 650°C), negative deviations from ideality are indicated at high X H 2 O . Some data were also collected in the H 2 O-NaCl and H 2 O-CO 2 -NaCl systems. In the former, H 2 O shows small positive deviations from ideality at 2 kbars, 850°C, which increase with decreasing X H 2 O . In the H 2 O-CO 2 -NaCl system, isofugacity lines for H 2 O were measured. In the two-phase region, these lines represent tie lines and, thus can be used to constrain the phase relations in the system.
Holloway John R.
Joyce David B.
No associations
LandOfFree
An experimental determination of the thermodynamic properties of H 2 O-CO 2 -NaCl fluids at high pressures and temperatures does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with An experimental determination of the thermodynamic properties of H 2 O-CO 2 -NaCl fluids at high pressures and temperatures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An experimental determination of the thermodynamic properties of H 2 O-CO 2 -NaCl fluids at high pressures and temperatures will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1274007