Obsidian: a potential natural analogue for nuclear waste glass

摘要

For long-term performance assessment of obsidian, wepresent computation chemistry and experimental datasets on glass dissolution and associated ionic releaseobtained after treating specimens under near hydrothermalconditions (for 1–64 h time intervals). TheEQ3/6 simulated results indicate appearance of quartz(chalcedony) and other mineral species. Besidesquartz, SEM-EDX of the precipitate shows presenceof smectite having two distinct microstructures whichconsist of small and large lamellae and their formationis linked with the release of Na, K and other ionsaccountable for increase in the pH and conductivity ofthe leachates. The former structure representsparagenesis of an earlier formed alteration product.These observations largely correspond to the simulatedresults, suggesting its suitability in geologicalrepository.