Investigation of SOMS and their related perovskites

Yali Su, Yu Li, Tina M. Nenoff, May D. Nyman, Alexandra Navrotsky, Hongwu Xu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

We are evaluating new metal niobate and silicotitanate ion exchangers for Cs and Sr removal and their related condensed phases as potential ceramic waste forms. The goal of the program is to provide the U.S. Department of Energy (DOE) with alternative materials that can exceed the solvent extraction process for removing Cs and Sr from high-level wastes and with technical alternatives for disposal of silicotitanate and niobate based ion exchange materials. One class of the new phases, which are Na2Nb2-xMIV xO6-x(OH)x·H2O(M IV=Ti, Zr, x = 0.04 ∼0.4, SOMS) and their thermally converted Sr loaded perovskites Na2-xSrxNb1.6Ti 0.4O5.8+0.5x (0 ≤ x ≤ 0.4), have been synthesized and characterized. SOMS exhibits very high Sr selectivity with Kd larger than 99,800 mL/g in the absence of competitive ions such as Na in solution, and about 103 mL/g when 0.1M Na presented in solution. This class of SOMS is easily converted to perovskites through low-temperature heat treatment (500 to 600 °C). The thermally converted perovskites exhibit extremely low Sr leach rates, ranging from 2.4 × 10-7 to 1 × 10-6 g/m2day for 5% to 20% Sr loading over a 7-day leaching period. Fractional Sr release FR% is 0.001% to 0.02% for 5% to 20% Sr loading over the 7-day leaching period. These results indicate SOMS could potentially be used for separating Sr from high-level waste and that their related perovskites could be used as potential ceramic waste forms.

Original languageEnglish (US)
Title of host publicationNuclear Waste Management Acconplishments of the Environmental Management Science Program
PublisherAmerican Chemical Society
Pages268-284
Number of pages17
ISBN (Print)0841239479, 9780841239470
DOIs
StatePublished - 2006
Externally publishedYes

Publication series

NameACS Symposium Series
Volume943
ISSN (Print)0097-6156

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

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