The Role of Boron in Monitoring the Leaching of Borosilicate Glass Waste Forms

Abstract

In the absence of any identified solid phase host (other than the original glass), boron has been assumed to accumulate in the fluid during the reaction of borosilicate glass waste forms with aqueous fluids. Using this assumption, it is possible to define a boron index which can be used to monitor the amount of glass that has been dissolved and to provide a worst-case measure of the degradation of the primary glass waste form. Several boron-containing silicate phases have been identified thus invalidating the assumption that boron does not precipitate. The effect is apparently small and the assumption that boron release is a direct measure of degree of alteration of borosilicate glass is still probably a good one.

Influence of zirconium on the structure of pristine and leached soda-lime borosilicate glasses: Towards a quantitative approach by 17O MQMAS NMR

“…Glass specimens were then leached in static mode, unstirred, at 90°C for 176 days until 652 days with a glass-surface-area-to-solution-volume ratio (SA/V) of 120 cm À1 . The quantity of altered glass was calculated from the boron release, as boron is a good glass alteration tracer [13].…”

Influence of glass composition and alteration solution on leached silicate glass structure: A solid-state NMR investigation

“…Usually, increasing SA/V ratio leads to a more rapid drop in the glass alteration rate whereas increasing the solution renewal rate increases the alteration rate (Delage et al, 1992;Gin, 2000). The quantity of altered glass was calculated from the boron release, as boron is a good glass alteration tracer (Scheetz et al, 1985). Gels were observed by SEM and no secondary phases were detected on their surfaces.…”

The effects of the glass surface area/solution volume ratio on glass corrosion: A critical review

“…4). A benefit of using boron as a measure of the glass reaction progress instead of an alkali metal is that boron is contained in very few secondary phases [68]. Alkali metals are contained in zeolite and clay phases that commonly form during glass corrosion.…”