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Kinetics of volatile extraction from carbonaceous chondrites: Dehydration of talcCarbonaceous chondrites are believed to be the primary constituents of near-Earth asteroids and Phobos and Deimos, and are potential resources of fuels that may be exploited for future planetary missions. Calculations of equilibrium phase relations suggest that talc (Ta) and antigorite (Ant) are likely to be the major hydrous phases in the C1 and C2 meteorites (Ganguly and Saxena, 1989), which constitute the most volatile rich classes of carbonaceous chondrites. The dehydration kinetics of talc are studied as a function of temperature, grain size, composition and fluid fugacity, as part of a systematic study of the reaction kinetics of the volatile bearing phases that are either known or likely to be present in carbonaceous chondrites. The dehydration kinetics were investigated at 1 bar, 775 to 875 C by monitoring the in-situ weight loss as a function of time of a natural talc. The talc platelets had a dimension of 0.8 to 1 micron. The run durations varied from 233.3 hours at 775 C (48 percent dehydration) to 20.8 hours at 875 C (80 pct. dehydration). The results can be adequately represented by a given rate equation. Theoretical analysis suggests that the reduction in the concentration of H2O in the environment of dehydrating talc, as would be encountered in processing chondritic materials, will have negligible effect on the rate of dehydration, unless there is a change of reaction mechanism owing to the presence of other volatile species.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Bose, Kunal
(Arizona Univ. Tucson, AZ, United States)
Ganguly, Jibamitra
(Arizona Univ. Tucson, AZ, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1991
Publication Information
Publication: Resources of Near-Earth Space: Abstracts
Subject Category
Lunar And Planetary Exploration
Accession Number
Distribution Limits
Work of the US Gov. Public Use Permitted.

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