Engineering topics

Cholsaipant, Pornsinee

Publications and source records attributed to Cholsaipant, Pornsinee.

3 records

DOE OSTI2022

Volatility of sodium, potassium, and cesium perrhenates determined by thermogravimetry

Here, in this study, we investigated the volatility of sodium, potassium, and cesium perrhenates using thermogravimetry (TG) performed on single salts and their binary mixed salts. We performed simultaneous TG and differential scanning calorimetry under a ramp heating condition at 10°C/min up to 1200°C to characterize volatilization behavior as a function of temperature. We also performed isothermal TG over a temperature range of 700 to 975°C to estimate the vapor pressures of the alkali perrhenates based on a modified Langmuir equation that relates the rate of free evaporation from the open surface to vapor pressure. In this paper, we discuss the results of our study on the temperature of evaporation and temperature-dependent vapor pressure of sodium, potassium, and cesium perrhenates in relation to rhenium volatilization behavior observed during melting of simulated waste glass.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2020

Thermal Properties of Sodium Borosilicate Glasses as a Function of Sulfur Content

SO3 additions, up to 3.0 wt%, were systematically investigated for effects on the physical properties of sodium borosilicate glass melted in air, with a sulfur-free composition of 50SiO2-10Al2O3-12B2O3-21Na2O-7CaO (wt%). Solubility measurements, using electron microscopy chemical analysis, determined the maximum loading to be ~1.5 wt% SO3. It was found that sulfur (here as sulfate) in this glass increased the glass transition temperature, thermal diffusivity, heat capacity, and thermal conductivity, and decreased the mass density. Structural analysis, performed with Raman spectroscopy, indicated that the borosilicate network polymerized with sulfur additions, presumably due to Na2O being required to charge compensate the ionic SO42- additions, thus becoming unavailable to form non-bridging oxygen in the silicate network. It is postulated that this increased crosslinking of the borosilicate backbone lead to a structure with higher dimensionality and average bond energy. This increased the mean free paths and vibration frequency of the phonons, which resulted in the observed increase in thermal properties.

Thermal properties, Borosilicate glass, Sulfur sol↗

DOE OSTI2020

Enhanced Hanford Low-Activity Waste Glass Property Data Development (Phase 3)

This work was performed for the U.S. Department of Energy (DOE) Office of River Protection (ORP) to provide expert evaluation and experimental work in support of the River Protection Project vitrification technology development1. The long-term objective of this work is to expand the property-composition database for Hanford site low-activity waste (LAW) glasses and property-composition models to cover the balance of the mission for the Hanford Waste Treatment and Immobilization Plant (WTP). When this effort is complete, enhanced LAW glass property-composition models will be developed.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗