IFMSC 2006

Analysis of modes of realization of Gibbs's free energy minimization method for prediction of processes of production of inorganic composites

D. Eristavi, D. Jincharadze, A. Gogishvili, A. Sarukhanishvili (Georgian Technical University)

ABSTRACT

For prediction of physical and chemical reactions taking place in the process of obtaining inorganic composites it is expedient to use Gibbs’s free energy minimization method (GTFEM).

There are many modes of realization of this method. This maltitude is expressed by a desire to grant the GTFEM method the functions of express-method and to bring to the minimum the absence of thermodynamic parameters in the information database for many compounds on the results of prediction.

Ample information was accumulated on the base of many-year analysis of modes of GTFEM realization of physical and chemical reactions going on in the process of obtaining inorganic composites. Critical consideration of this information enable us to formulate the below presented conclusions:

If the reagents of the processes belong to unhydrous inorganic compounds, Ulikh’s first approximation gives rather reliable results at temperatures below 800K,

If reagents contain adsorbed or structurally joined water, at temperatures below 1100K it is expedient to use Ulikh’s second approximation,

For evaluation of processes going on at high temperatures the GTFEM ,realization method offered by Schwartzmann and Temkin in most cases give the results similar to those obtained by the use of equations based on the first and second laws of thermodynamics (classical mode),

In case of absence of data about standard and high temperature heat capacity of compounds in the database, the Landia’s method of computing or definite branching of this method can be used successfully.