Synthesis, Characterization and Ion Exchange of Novel Sodium Niobate Phases

Due to the extreme complexity of DOE mixed wastes (i.e. Hanford tank solutions), a variety of advanced processes are necessary to separate out hazardous radioactive and RCRA metals so that these wastes may be processed and disposed with minimal cost and maximum efficiency. Therefore, there is an ongoing effort to produce and test new phases with novel ion exchange properties for waste cleanup applications. We present here the synthesis of a novel class of thermally and chemically stable, microporous, niobate-based, ion exchanger materials. Ion exchange studies show these new phases are highly selective for Sr²⁺ and other bivalent metals. Additionally, the Sr-loaded ion exchangers undergo direct thermal conversion to perovskite, a highly durable phase with potential waste form applications.