Characterization of an alkali alumina-borosilicate glass considered for storage of radioactive waste

A petrologic study of a crucible of Glass Formula 127 revealed physical and compositional heterogeneities. The melting process led to compositional he terogeneity within the glass form and to glass compositions different than that predicted by targeted compositions. Aluminum was into the melt from th e crucible wall, and it is suspected that Si diffused outward into the cruc ible. the elements present as surrogates for radioactive elements of concer n in waste material, none to follow Si. Differences in composition between batch composition and final glass composition are also caused by volatiliza tion of B, Na, and Li. from the Al:Si exchange, the heterogeneity in trace element contents is more noticeable than that of major oxides. Trace elemen t: correlations and heterogeneity, combined with skeletal fluorite concentr ated into crystal-rich (up to 60 vol%) and poor bands, supports a process o f melt differentiation through convective crystallization.