Publikationsserver der RWTH Aachen University
The experimental and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al 2 O 3 -SiO 2
Abstract
dc:descriptionThe purpose of the present investigation is to illustrate experimental methods for the measurement of accurate thermodynamic data in silicate glasses and melts, and then to determine thermochemical properties by those methods in order to compare with calculated values. Thermodynamic properties of CaO in the melts in the system (CaO-MgO-Al2O3-SiO2) are investigated by electrochemical and calorimetric methods. Activities of CaO are measured in the temperature range 1473 K to 1573 K using EMF measurement. Partial molar mixing enthalpies of CaO are directly measured using isothermal drop calorimetry at 1732 K. The vitrification enthalpy (Hvit) of glassy samples was also measured by the isothermal drop calorimeter. The measurements for the vitrification enthalpy were carried out in the temperature range from room temperature T0 (295 K) to the calorimetric temperature Tk (1732 K). Enthalpy data were determined from the enthalpy difference DH (Tk – T0). The glass transformation temperature (Tg) and the jump of the heat capacity at Tg (Dcp) were measured by a dynamic operating calorimeter (DSC). For the sake of the comparison of the experimentally determined activities, two models (F*A*C*T and the constitutional model) are adopted to calculate activities of CaO in the silicate melts. The calculated values agree within ± 0.2 as decadal logarithms with the measured values.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2004
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Shin, Jin-Wook
- Contributors dc:contributor
-
- Conradt, Reinhard
Subjects
dc:subject × 8Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- eng
Identifiers
dc:identifier.*- OAI identifier oai:identifier
- oai:publications.rwth-aachen.de:59938