Thermal Processing Optimization for Simulated Hanford Waste Glass (AZ 101)
This paper presents the results of a Time-Temperature-Transformation (TTT) study of the effect of different heat treatments on the final form and durability of the wasteform produced by the vitrification of Hanford High Level Waste (HLW). A borosilicate glass formulation containing 60 weight % of a Hanford Tank AZ 101 simulant approximated the radioactive waste glass. The TTT diagram was generated by analyzing thirty-six wasteforms produced by melting the frit-waste mixture at 1450°C, and then heat-treating the melts at specified temperatures for a predetermined length of time. The temperatures studied ranged from 500°C to 1200°C, and the length of the heat treatments ranged from 0.75 hour to 768 hours (32 days). The wasteforms produced were analyzed by Toxicity Characteristic Leaching Procedure (TCLP), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) - Energy Dispersive Spectrometry (EDS). Rietveld analysis was performed on some of the XRD results. Crystalline forms detected include transition metal (predominantly Fe) spinel, zircon, zirconia, and iron oxide. These crystalline forms are characteristic to specific heat treatment conditions. The types or concentrations of crystals have little to no impact on the Product Consistency Test (PCT) performance of the wasteform. The results show a strong relationship between heat treatment conditions (time and temperature) and TCLP test response for cadmium only. Samples heat-treated at higher temperatures or longer periods of time show a considerably higher cadmium response (by TCLP) than samples heat-treated at lower temperatures or for shorter times.
A. Giordana and W. G. Ramsey and T. F. Meaker and B. Kauffman and M. McCarthy and K. Guilbeau and J. D. Smith and F. S. Miller and T. Sanders and E. W. Bohannan and For full list of authors, see publisher's website., "Thermal Processing Optimization for Simulated Hanford Waste Glass (AZ 101)," Ceramic Transactions, vol. 155, pp. 351 - 360, American Ceramic Society, Apr 2004.
The definitive version is available at https://doi.org/10.1002/9781118407004.ch33
Science and Technology in Addressing Environmental Issues in the Ceramic Industry and Ceramic Science and Technology for the Nuclear Industry Symposia at the 105th American Ceramic Society Annual Meeting and Exposition: (2003: Apr. 27-30, Nashville, TN)
Materials Science and Engineering
Keywords and Phrases
Glass wasteforms; Melter temperature; Time temperature transformation (TTT); Toxicity characteristic leaching procedure (TCLP), Energy dispersive spectroscopy; Glass manufacture; Heat treatment; Leaching; Optimization; Radioactive waste vitrification; Scanning electron microscopy; X ray diffraction, Radioactive wastes
International Standard Book Number (ISBN)
International Standard Serial Number (ISSN)
Article - Conference proceedings
© 2004 American Ceramic Society, All rights reserved.
01 Apr 2004