The system albite-H/sub 2/O-CO/sub 2/: a model for melting and activities of water at high pressures

Journal Article · Sat May 01 00:00:00 EDT 1982 · Am. Mineral.; (United States)

OSTI ID:6840987

Bohlen, S R ^[1]; Boettcher, A L; Wall, V J

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1. Univ. of California, Los Angeles

The melting of albite in the presence of H/sub 2/O-CO/sub 2/ vapor has been determined in piston-cylinder apparatus from 5 to 25 kbar for mole fractions of H/sub 2/O in the vapor (X/sub H//sub 2//sub O//sup V/) from 1.0 to 0.0. Albite in the presence of CO2-rich vapor melts as much as 150-300/sup 0/C lower than indicated by previous theoretical and experimental studies. The albite-CO/sub 2/ melting curve is indistinguishable from the vapor-absent melting curve up to 15 kbar, but it is significantly lower above 15 kbar as a result of a substantial increase in the solubility of CO/sub 2/ in the liquid. Calculated activity coefficients (..gamma..) for water in H/sub 2/O-CO/sub 2/ vapor in the range 700-1000/sup 0/C, 5-15 kbar are everywhere greater than unity and increase isobarically and isothermally toward CO/sub 2/-rich compositions. For X/sup V//sub H//sub 2//sub O/ < 0.3 calculated ..gamma../sup V//sub H//sub 2//sub O/ are significantly greater than those predicted by the modified Redlich-Kwong equation.

• OSTI ID: 6840987
• Journal Information: Am. Mineral.; (United States), Journal Name: Am. Mineral.; (United States) Vol. 67:5-6; ISSN AMMIA
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
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58 GEOSCIENCES
580300* -- Mineralogy
Petrology
&amp; Rock Mechanics-- (-1989)
ALBITE
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
FELDSPARS
HYDROGEN COMPOUNDS
MELTING
MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
SILICATE MINERALS
SOLUBILITY
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
WATER