Member, The American Ceramic Society
Solution-Derived, Chloride-Containing Minerals as a Waste Form for Alkali Chlorides
Article first published online: 18 JUL 2012
Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Journal of the American Ceramic Society
Volume 95, Issue 10, pages 3115–3123, October 2012
How to Cite
Riley, B. J., Crum, J. V., Matyáš, J., McCloy, J. S., Lepry, W. C. (2012), Solution-Derived, Chloride-Containing Minerals as a Waste Form for Alkali Chlorides. Journal of the American Ceramic Society, 95: 3115–3123. doi: 10.1111/j.1551-2916.2012.05363.x
- Issue published online: 2 OCT 2012
- Article first published online: 18 JUL 2012
- Manuscript Accepted: 15 JUN 2012
- Manuscript Received: 16 MAR 2012
- U.S. Department of Energy, Office of Nuclear Energy. Grant Number: DE-AC05-76RL01830
Sodalite (Na8(AlSiO4)6Cl2) and cancrinite ((Na,K)6Ca2(AlSiO4)6Cl4) are environmentally stable, chloride-containing minerals that are a logical waste form option for the mixed alkali chloride salt waste stream that is generated from a proposed electrochemical separations process during nuclear fuel reprocessing. Here, we discuss a low-temperature, solution-based process to make these phases where sodalite particles are produced in the form of a fine powder with particle sizes on the order of 1–10 μm. Due to the small particle size, these powders require additional treatment to form a monolith. In this study, the powders were pressed into pellets and fired to achieve >90% of the theoretical density of sodalite (2.27 × 10−3 kg/m3). The cancrinite structure, identified as the best candidate mineral form in terms of waste loading capacity, was only produced on a limited basis but was converted to sodalite upon firing. Here, we discuss the specifics of the solution-based approach, the chemical durability of select waste forms as well as the steps taken to maximize the chloride-containing phases, decrease chloride loss during pellet firing, and to increase pellet densities.