ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Determination of the enthalpy of crystallization of eutectic melt in the system 2CaO.Al₂O₃.SIO₂-CaO.SiO₂

K. Adamkovičová, L. Kosa, I. Proks, and I. Tarina

Institute of Inorganic Chemistry, Centre for Chemical Research, Slovak Academy of Sciences, CS-842 36 Bratislava

Abstract: Using a precursor method the melt of eutectic composition in the system  2CaO.Al₂O₃.SIO₂-CaO.SiO₂ (45.6 mass % CaO; 13.4 mass % Al₂O₃; 41.0 mass % Si0₂) was prepared. The temperature dependence of the specific relative enthalpy of the eutectic melt was determined using the experimental data obtained in "drop" calorimeter and in the calorimeter for determina­tion of heats of dissolution. Preparation of gehlenite (2CaO • Al₂O₃•Si0₂) and wollastonite (CaO Si0₂) which are the products of crystallization of the eutectic melt and the temperature dependences of their specific relative enthalpy were published in the previous papers. On the basis of the values of the specific relative enthalpy of the eutectic melt, gehlenite, and wollas­tonite at the equilibrium temperature of crystallization of the eutectic melt 1591 К and from the material balance of this crystallization the specific enthalpy of crystallization of the eutectic melt was determined Δh_cryst(eut. melt; 1591 K) = (-286 ± 18) kJ kg^-1 The error was determined on the level of significance equal to 95 %.

Full paper in Portable Document Format: 431a17.pdf

Chemical Papers 43 (1) 17–23 (1989)