An AEM study of glass-palagonite interfaces formed in Hawaiian basalt glasses
Basalt glass has been used as a natural analogue of high-level waste glass because both types of glass have similar Si contents. Most important for identifying the dominant long-term corrosion process is the exact chemical nature of the glass-palagonite boundary. In this paper, the authors present the results of a detailed study of alteration interfaces formed in subaerially altered Hawaiian basalt glasses (400 to 700 years old) and analyzed with high resolution transmission electron microscopy (TEM) and nanometer-size energy dispersive x-ray spectrometric (EDS) probe. The study reveals a sharp contact between fresh glass and alteration products at nanometer scale. The alteration products, which were typically several nanometers in size, were found to be iron oxide hydroxide (goethite), aluminum hydroxide hydrate (scarbroite), and an Si-Fe-Al rich amorphous phase. The EDS line profile across the boundary showed a zone of 60--130 nm thickness that is depleted in alkali elements but exhibits no variation for silicon. These results point to a dominant dissolution-precipitation mechanism plus a limited ion-exchange process under subaerial conditions.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 495701
- Report Number(s):
- ANL/CMT/CP-91771; CONF-970568-3; ON: DE97053127; TRN: AHC29715%%20
- Resource Relation:
- Conference: 99. annual meeting of the American Ceramic Society, Cincinnati, OH (United States), 4-7 May 1997; Other Information: PBD: [1997]
- Country of Publication:
- United States
- Language:
- English
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