Accession Number : AD0283133

Title :   THE DEHYDRATION OF GYPSUM. PART II. THE OXIDATION KINETICS OF TANTALUM IN CARBON DIOXIDE

Corporate Author : UTAH UNIV SALT LAKE CITY

Personal Author(s) : RICHARDS,KENNETH J.

Report Date : AUG 1962

Pagination or Media Count : 1

Abstract : The dehydration of both polycrystalline and single crystal samples of gypsum was studied in the temperature range 99 to 142 C by means of visual observation, infrared spectroscopy, X-ray diffraction, and thermogravimetric techniques. Samples of Ta were oxidized in CO2AT VARIOUS PARTIAL PRESSURES IN THE TEMPERATURE RANGE 700 TO 950 C and in CO2-CO mixtures in the range 760 to 820 C. The reaction involved linear oxidation which was associated with the formation of a nonprotective layer of Ta2O5. Below about 720 C, there was a change in the rate-determining mechanism, and above 840 C the linear reaction was preceded by a region of nonlinear oxidation. (Author)

Descriptors :   *GYPSUM, *TANTALUM, CARBON COMPOUNDS, CARBON DIOXIDE, CRYSTALS, DEHYDRATION, GRAVIMETRIC ANALYSIS, HIGH TEMPERATURE, INFRARED SPECTROSCOPY, MEASUREMENT, MONOXIDES, OXIDATION, REACTION KINETICS, SINGLE CRYSTALS, TEMPERATURE, THERMODYNAMICS, X RAY DIFFRACTION

Distribution Statement : APPROVED FOR PUBLIC RELEASE