Relationship between leaching behavior and glass structure of calcium-aluminoborate waste glasses with various La2O3 contents

Abstract

We investigated the correlation between the structures of 4-component glasses (B2O3–CaO–Al2O3–La2O3) and their leaching behaviors. We used a FT-IR and a MAS-NMR to analyze the structures of ground as-prepared and leached glasses for 7 and 28 days. Elemental releases represent that the leaching was incongruent. After leaching 28 days, BO4 structure dramatically decreased and AlO6 ratio increased compared to the glasses before the leaching test. That might be because these structures in the glasses were broken or released into solution during the leaching test. The addition of La3+ into the glass stabilizes the formation of BO4 and more highly charged AlO5 and AlO6.