Cluster formation of silica particles in glass batches during melting

Schweiger, Michael J.; Hrma, Pavel R.; Humrickhouse, Carissa J.; Marcial, José; Riley, Brian J.; Tegrotenhuis, Nathan E.

doi:10.1016/j.jnoncrysol.2010.04.009

Cited by 68 publications

(91 citation statements)

References 9 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To obtain concrete shapes of the γ(T) function, we used experimental data for the dissolution of crushed quartz while heating batches formulated for a high-alumina, high-level waste as reported in [1,13,14]. We have selected four batches containing silica particles of 45, 75, 150, and 195 μm.…”

Section: Experimental Datamentioning

confidence: 99%

See 1 more Smart Citation

Dissolution retardation of solid silica during glass-batch melting

Hrma

Marcial

2011

Journal of Non-Crystalline Solids

Self Cite

View full text Add to dashboard Cite

During glass-batch melting, solid silica (quartz) usually dissolves last. The measured rate of dissolution, while the temperature was increasing at a constant rate, was compared with the hypothetical diffusion-controlled volume flux from regularly distributed particles through concentration layers of a uniform thickness. The actual rate was up to two orders of magnitude lower than that of the "ideal" case, revealing a progressive inhibition of silica dissolution. As a measure of this retarded dissolution, we introduced a retardation factor defined as a ratio of the actual and "ideal" dissolution rates measured as the volume flux at the melt-particle interface. The severe inhibition of silica dissolution has been attributed to the irregular spatial distribution of silica particles that is associated with the formation of nearly saturated melt on a portion of their surfaces. Irregular shapes and unequal sizes of particles also contribute to their extended lifetime.

show abstract

Section: Experimental Datamentioning

confidence: 99%

“…Note that the rate of dissolution changes little over a wide temperature interval of~400 K. Fig. 3 presents an example [14] of a measured concentration distribution of silica at the dissolving quartz particle.…”

Section: Experimental Datamentioning

confidence: 99%

Dissolution retardation of solid silica during glass-batch melting

Hrma

Marcial

2011

Journal of Non-Crystalline Solids

Self Cite

View full text Add to dashboard Cite

show abstract

“…Quartz dissolution is a diffusion-controlled process that is influenced by numerous factors, such as the presence and motion of bubbles, the extent of overlap of concentration boundary layers, the nonuniform spatial distribution and irregular shapes of particles, and the particle-size distribution. 6,[17][18][19] Fortunately, a simple, yet sufficient and adequate, quartz dissolution kinetics can be represented by the nth order empirical equation: 12…”

Section: Reaction Kineticsmentioning

confidence: 99%

“…5 While little can be done with the form of the waste other than basic pretreatment that separates waste components into waste streams, chemical and physical forms of additive ingredients can be optimized. 5,6 The goal is to minimize primary foam through releasing most if not all batch gases before the glass-forming melt becomes connected 2 while delaying the development of a continuous glass-forming melt before the batch gases are fully released.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation and Mathematical Modeling of Cold Cap Behavior in High‐Level‐Waste Glass Melter

Hrma

2014

Ceramic Transactions Series

Self Cite

View full text Add to dashboard Cite

The cold cap is a layer of reacting melter feed floating on the surface of molten glass in a glass-melting furnace. The cold cap consists of two distinct portions, the upper portion which allows the reaction gases to escape through open pores, and the lower portion which traps the gases within the continuous glass-forming melt, creating foam. The temperature span over the cold cap is ~1000 K. Data needed to simulate the cold cap mathematically include the kinetics of multiple reactions, reaction enthalpies, heat capacity, density, porosity, and heat conductivity as functions of both the temperature and the rate of heating. These data were produced via crucible experiments. The mathematical model has been completed. It relates the cold cap thickness, the rate of melting, the temperature field, and cold cap structure (foaming, dissolution of quartz particles, and formation and subsequent dissolution of crystalline phases, such as spinel) to the cold cap bottom temperature, the fraction of heat flow to the upper cold cap surface, the melt foaminess, and the chemical and physical nature of melter feed materials. To verify the model, cold caps were produced in a laboratory-scale melter and their structure is currently investigated.

show abstract

“…Yet hardly any mixture found in nature or industrial technology has as many components and undergoes as many reactions as melter feeds during vitrification of nuclear wastes [20,21]. The waste itself contains compounds of 40 to 60 elements [22] that react with glassforming additives on heating.…”

Section: Introductionmentioning

confidence: 99%

Melting of glass batch: Model for multiple overlapping gas-evolving reactions

2012

Self Cite

View full text Add to dashboard Cite

In this study, we present a model for the kinetics of multiple overlapping reactions.Mathematical representation of the kinetics of gas-evolving reactions is crucial for the modeling of the feed-to-glass conversion in a waste-glass melter. The model simulates multiple gas-evolving reactions that occur during heating of a high-alumina high-level waste melter feed. To obtain satisfactory kinetic parameters, we employed Kissinger's method combined with least-squares analysis. The power-law kinetics with variable reaction order sufficed for obtaining excellent agreement with measured thennogravimetric analysis data.

show abstract

Cluster formation of silica particles in glass batches during melting

Cited by 68 publications

References 9 publications

Dissolution retardation of solid silica during glass-batch melting

Dissolution retardation of solid silica during glass-batch melting

Experimental Investigation and Mathematical Modeling of Cold Cap Behavior in High‐Level‐Waste Glass Melter

Melting of glass batch: Model for multiple overlapping gas-evolving reactions

Contact Info

Product

Resources

About