DATA PACKET FOR THE FRIT 202-A11 SB3 GLASS SYSTEM A CANDIDATE FOR THE COLD CRUCIBLE INDUCTION MELTER DEMONSTRATION

A demonstration of the Cold Crucible Induction Melter (CCIM) technology is currently planned for the fall of 2007 to assess the potential for attaining higher waste throughputs as compared to joule heated melter technology. The CCIM demonstrations will be based on a Defense Waste Processing Facility (DWPF) waste slurry feed surrogate with a nominal operating temperature of approximately 1250 C (higher temperatures may be used). The waste slurry feed (nominally 45-50 weight percent solids) surrogate will be representative of Sludge Batch 3 (SB3) in order to allow a direct comparison to the DWPF joule heated melter performance during processing of this sludge waste. This pilot scale demonstration is being conducted to evaluate performance and to identify potential processing issues with the existing CCIM technology, and it will include characterization of the resultant glass product to ensure current product performance (durability) specifications are met. The information presented in this data packet provides a technical basis from which decisions regarding the melter demonstration can be made. More specifically, the results presented in this report provide technical data on the impact of waste loading (WL) on critical properties of interest--in particular, durability, liquidus temperature, and viscosity. All of the glasses of this study,more » regardless of heat treatment, were acceptable when their durabilities were compared to those of the Environmental Assessment (EA) glass. In general, as WL increases, the durabilities for the quenched versions of the glasses tend to decrease due to the changing composition of the glass. For the glasses subjected to the canister centerline cooling (ccc) regime, the durability response appears to be more non-linear as WL increases. At WLs less than 50%, X-ray diffraction (XRD) analysis indicates the potential for the presence of aegirine and/or nepheline crystalline phases, and when these phases are present, there is a decrease in the durability of the glass. As WL is increased above 50%, there is a transition from the aegirine and/or nepheline phases to a spinel phase field leading to more durable glasses. The results for durability suggest that WLs of 50% or greater should be targeted for the CCIM demonstration, thus, avoiding the potential for the formation of aegirine and/or nepheline. However, if decisions to target WLs of 50% or greater are made, liquidus temperature (T{sub L}) measurements indicate that there could be some degree of crystallization within the melter if a nominal 1250 C temperature is used. It is also anticipated that increasing WLs will lead to higher T{sub L}'s. Specifically, the T{sub L} of the 50% WL glass (HTLG-21) was measured to be slightly above 1250 C. To minimize the potential of crystallization during processing, higher melt temperatures could be targeted which not only could allow for higher WLs to be obtained but will also result in a reduction in viscosity, which in itself could pose certain processing issues (the ability to control the pour and the possibility of increased volatility). The viscosity of the 50% WL glass at 1250 and 1300 C was measured to be 20 and 13 Poise, respectively. Thus, a balance between processing and product performance issues may be required for the initial CCIM demonstrations since the frit development efforts to date were not necessarily intended to optimize this glass system nor have these efforts accounted for the variation from the intended target that is likely to occur in the composition of the waste slurry feed surrogate that is being used in the study. « less