A5032726828- Glass properties and applications
- Recycling and utilization of industrial and municipal waste in materials production
- Material Dynamics and Properties
- Nuclear materials and radiation effects
- Pigment Synthesis and Properties
- Radioactive element chemistry and processing
- Iron and Steelmaking Processes
- Polymer Foaming and Composites
- Cultural Heritage Materials Analysis
- Enhanced Oil Recovery Techniques
- Thermal and Kinetic Analysis
- Heat and Mass Transfer in Porous Media
- Pickering emulsions and particle stabilization
- Catalysis and Oxidation Reactions
- Metallurgical Processes and Thermodynamics
- Phase Equilibria and Thermodynamics
- Polymer composites and self-healing
- Nuclear Materials and Properties
- Radiative Heat Transfer Studies
- Gas Dynamics and Kinetic Theory
- Material Science and Thermodynamics
- Mineralogy and Gemology Studies
- Iron oxide chemistry and applications
- Hydrocarbon exploration and reservoir analysis
- CO2 Sequestration and Geologic Interactions
Government of the United States of America
2023-2024
Pacific Northwest National Laboratory
2020-2024
University of Chemistry and Technology, Prague
2013-2019
The activation energy of glass melt viscosity, η, is nearly constant at temperatures which η < 100 Pa s. Provided that the preexponential factor a composition-independent constant, only function composition, and viscosity–composition relationships utmost simplicity can be formulated to provide welcome advantage in computational fluid dynamics modeling melting furnaces processing multicomponent glasses. Using dataset with over 3000 viscosity values acquired experimentally for temperature...
Abstract Although the vitrification of nuclear waste has a decades‐long history, numerous opportunities still exist to improve its efficiency and increase loading in glass. This is especially true for low‐activity (LAW), which been historically treated by other immobilization technologies less mature than high‐level (HLW) vitrification. In this work, we address one least understood phenomena during conversion feeds glass—the formation molten salt transient glass‐forming melt. Using...
Abstract Understanding the batch‐to‐glass conversion process is fundamental to optimizing performance of glass‐melting furnaces and ensuring that furnace modeling can correctly predict observed outcome when batch materials or conditions change. To investigate kinetics silica dissolution, gas evolution, primary foam formation collapse, we performed X‐ray diffraction, thermal gravimetry, feed expansion tests, evolved analysis samples heated at several constant heating rates. We found evolving...
Abstract A recently proposed glass melting rate correlation (MRC) equation expresses an essential relationship between the and material process variables (melt viscosity, cold‐cap bottom temperature, feed‐to‐glass conversion heat, melter operating bubbling flux). It agreed well with data for high‐level waste (HLW) feeds processed in electric melter. However, nonlinear form four coefficients made original MRC somewhat cumbersome representing existing sets. Introducing new (glass melt density...
This study describes the development of a batch-to-glass conversion model for container-glass melting furnace. The accounts relationship between temperature history batch particles, properties, and rate by coupling heat transfer kinetics models. within is modeled spatially one-dimensional, convective-conductive balance, while described using stretched exponential, differential Avrami, Šesták–Berggren models based on silica dissolution data. We show that simulated significantly changes when...
Abstract A predictive model of melt rate in waste glass vitrification operations is needed to inform melter during normal and off‐normal operations. This paper describes the development a cold cap (the reacting feed floating on molten melter) that couples heat transfer with feed‐to‐glass conversion kinetics. The was applied four feeds designed for high‐level low‐activity nuclear using material properties, either measured or estimated, obtain temperature distribution within cap. model, when...
Abstract The rate of conversion nuclear waste melter feed to glass is affected by the selection materials and design operation. melting correlation (MRC) an equation that relates production with two types variables: (a) melt properties: heat, cold‐cap bottom temperature, viscosity; (b) operation parameters: geometry, operating gas bubbling rate. MRC shows good agreement for extended data set high‐level (HLW) feeds a generated low‐activity (LAW) feeds. Laboratory observation heated samples...
Abstract A recently developed model of the cold cap—the reacting glass batch (melter feeds) floating on molten in an electric melter—couples heat transfer with feed‐to‐glass conversion kinetics. The allows for determining distributions temperature and various properties within cap. In present study, this is applied to four melter feeds designed high‐level low‐activity nuclear wastes. Profiles temperature, degree, cap porosity density, condensed matter velocity, heating rate were determined...
Abstract As glass batch is charged into an electric melter, a cold cap forms on the melt surface. Heat transfer to from molten below and melter atmosphere above determines melting rate. A mathematical model of experimental kinetic data feed‐to‐glass conversion that were collected for several simulated low‐activity high‐level waste feeds allowed us develop relationships between internal structure cap, its properties, thickness, heat transfer. This contribution shows distribution major...
Abstract The glass transition temperature ( T g ) is a parameter used in many melt viscosity models as it denotes around which liquid‐glass occurs. In this work, values were measured for series of low‐activity waste (LAW) glasses using differential scanning calorimetry. These data combined with other available from literature. dataset, consisting 137 points, was the development several to estimate composition. When testing number influential components and different supervised learning...