Thermodynamics Research Center / ThermoML | Thermochimica Acta

A DSC study of the NaNO3 KNO3 system using an innovative encapsulation technique

Benes, O., Konings, R. J. M., Wurzer, S., Sierig, M., Dockendorf, A.
Thermochim. Acta 2010, 509, 1-2, 62-66
ABSTRACT
An innovative encapsulation technique designed for the DSC high temperature measurements of the volatile samples is presented in this study. Stainless steel crucibles with a screwed bolt were developed for this purpose. The technique was demonstrated on the phase diagram measurement of the NaNO3 KNO3 system and the obtained results are presented in this study. Up to date two thermodynamic assessments of the NaNO3 KNO3 phase diagram have been made, one characterized by a single eutectic point with limited solubilities in the solid state in both NaNO3 and KNO3 rich corners, whereas the other version prefers a continuous solid solubility with minimum on the liquidus line. Based on our results we confirm limited solubilities in the solid state.
Compounds
# Formula Name
1 NNaO3 sodium nitrate
2 KNO3 potassium nitrate
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA:UFactor:4
  • 1
  • POMD
  • 2
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 2
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA:UFactor:4
  • 1
  • POMD
  • 1
  • 2
  • Eutectic temperature, K ; Crystal - 1
  • Crystal - 1
  • Crystal - 2
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • 2
  • Eutectic composition: mole fraction - 2 ; Crystal - 1
  • Crystal - 1
  • Crystal - 2
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Liquid
  • Mole fraction - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • DTA:UFactor:4
  • 15
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Liquid
  • Mole fraction - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 2
  • DTA:UFactor:4
  • 11
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Crystal
  • Mole fraction - 2; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • Liquid
  • DTA
  • 6