Start |Author Index | View Uploaded Presentations | Meeting Information

2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 65-10
Presentation Time: 4:20 PM

SOLUBILITY AND CALORIMETRY STUDIES OF K-ZIPPEITE: DETERMINATION OF STANDARD STATE THERMODYNAMIC PROPERTIES


SHARIFIRONIZI, Melika, Civil and Environmental Engineering and Earth Science, Uni of Notre Dame, 301 Stinson Remick Hall, Notre Dame, IN 46637, BURNS, Peter C., Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 301 Stinson Remick Hall, Notre Dame, IN 46556, FEIN, Jeremy B., Civil & Environmental Engineering & Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 and SZYMANOWSKI, Jennifer, Civil and Environmental Engineering and Earth Science, Uni of Notre Dame, 301 Stinson Remick Hall, Notre Dame, IN 46556, msharifi@nd.edu

Zippeite is a uranyl sulfate mineral that is widespread in U deposits that contain sulfides and are oxidized, and is a common constituent of mine wastes. The stability of different uranyl mineral phases plays an important role in determining geologic nuclear waste repository performance. In this study, we synthesized K-zippeite, K3(H2O)[(UO2)4(SO4)2O3(OH)], and completed solubility and calorimetric studies. The enthalpy of formation of zippeite was calculated from the enthalpy of dissolution in a high-temperature oxide melt solution calorimeter. Solubility measurements were conducted both from undersaturation and from supersaturation in order to demonstrate and constrain equilibrium. Using the log solubility product that was calculated from the solubility measurements(log Ksp), the standard state Gibbs-free energy was determined at T=297K. The Gibbs free energy of formation of zippeite, coupled with its enthalpy of formation, was then used to calculate the standard entropy of formation.

Session No. 65

T134. Radiation Effects, Mineralogy, and Materials Science of Actinides II: In Honor of Rodney C. Ewing, 2015 Roebling Medalist
Sunday, 1 November 2015: 1:30 PM-5:30 PM
Room 317 (Baltimore Convention Center)
Geological Society of America Abstracts with Programs. Vol. 47, No. 7, p.203
© Copyright 2015 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.
Back to: T134. Radiation Effects, Mineralogy, and Materials Science of Actinides II: In Honor of Rodney C. Ewing, 2015 Roebling Medalist
<< Previous Abstract | Next Abstract >>