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

• Published in: Journal of thermal analysis and calorimetry Vol. 147; no. 17; pp. 9291 - 9299
• Main Authors: Cholsaipant, Pornsinee, George, Jaime L., Kim, Dongsang, Kruger, Albert A.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.09.2022; Springer; Springer Nature B.V
• Subjects: alkali perrhenate; Analytical Chemistry; Calorimetry; Cesium; Chemistry; Chemistry and Materials Science; Diffusion rate; Evaporation rate; Heating; Inorganic Chemistry; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Interdiffusion; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Potassium; rhenium; Sodium; technetium; thermal analysis; Thermogravimetry; Vapor pressure; Vaporization; Volatility; volatilization; Technetium; Thermal analysis; Rhenium; Alkali perrhenate; Volatilization
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-021-11173-8

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 700–975 °C. To estimate the relative differences in the vapor pressure of the alkali perrhenates we adopted a published equation on the vaporization mass loss rate during diffusion-controlled evaporation, applied a proposed equation on the interdiffusion coefficient of vapors, and used the literature data available on vapor pressure for KReO 4 . Both the temperature ranges of evaporation determined by TG under ramp heating conditions and the vapor pressure estimated from isothermal TG support that the order of volatility of alkali perrhenates is CsReO 4  > KReO 4  > NaReO 4 . This result does not support the unusual volatility order of KReO 4  > CsReO 4  > NaReO 4 observed from Hanford LAW glass feeds, which suggests that the volatility of the perrhenates is likely dependent on the composition of salt in which the perrhenates are dissolved.