Study of the water content in zeolitic tuffs from the Nevada Test Site

Conference · Fri Mar 26 00:00:00 EST 1976

OSTI ID:7347471

Knowlton, G D; McKague, H L

Thermal gravimetric analysis (TGA) was employed to gain quantitative information about adsorbed, zeolite (in channels and cages), and coordinated water present in powdered zeolitic tuffs from the U.S. Energy Research and Development Administration's Nevada Test Site. Thermal gravimetric analysis of powdered tuff samples, ranging from 40 to 60 percent clinoptilolite, was performed under N/sub 2/ atmosphere and vacuum with a 2/sup 0/C/min heating rate. The TGA plots obtained exhibited three linear portions; each is assumed to represent a specific type of water lost over a given temperature range. The linear portions are separated by curved sections that represent a transition in the type of water being evolved. Evaluation of these plots suggests that adsorbed water is lost between 25/sup 0/ and 90/sup 0/C, zeolite water between 70/sup 0/ and 300/sup 0/C, and coordinated water between 200/sup 0/ and 700/sup +0/C. It was found that all adsorbed water could be removed in 1 to 2 h at ambient temperature (25/sup 0/C) using vacuum only, while removal of significant amounts of zeolite water required increasing the temperature above ambient. The clinoptilolite content of the samples, based on the percent zeolite water, when normalized against the measured zeolite-water content of a pure clinoptilolite sample, generally agrees with the amount of clinoptilolite as estimated by X-ray diffraction analysis. The powdered tuff samples analyzed in this study contained an average of 4.6 +- 0.2 percent adsorbed water, 4.9 +- 0.3 percent zeolite water, and 1.7 +- 0.1 percent coordinated water, for an average total weight loss at complete dehydration of 11.1 +- 0.4 percent.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• OSTI ID: 7347471
• Report Number(s): UCRL-78013; CONF-760626-1
• Resource Relation: Conference: Zeolite conference, Tucson, AZ, USA, 6 Jun 1976
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
NEVADA TEST SITE
GEOCHEMISTRY
TUFF
THERMAL GRAVIMETRIC ANALYSIS
ZEOLITES
CHEMICAL ANALYSIS
CLINOPTILOLITE
WATER
X-RAY DIFFRACTION
CHEMISTRY
COHERENT SCATTERING
DIFFRACTION
GRAVIMETRIC ANALYSIS
HYDROGEN COMPOUNDS
IGNEOUS ROCKS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MINERALS
OXYGEN COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
ROCKS
SCATTERING
THERMAL ANALYSIS
580400* - Geochemistry- (-1989)