Thermodynamics of the reactive phase formation of the binder of the CoO–BaO–Al2O3 system for electromagnetic radiation protection

The article discusses the physicochemical basis for the production of barium aluminate binders, supplemented with compounds and solid solutions including cobalt oxide. The results of calculating the temperature dependence of Gibbs free energy are presented for model reactions simulating all possible variants of two-phase equilibria in the CoO–BaO–Al2O3 system. Using thermodynamic analysis, the stability of the terminals of the above system is established, which makes it possible to triangulate it. The complete subsolidus structure is presented, as well as the geometric and topological characteristics of the CoO–BaO–Al2O3 system and its phases. The presented results of thermodynamic analysis of solid-phase reactions involving barium aluminates and cobalt-containing oxides allow comparing the paths of reaction phase formation of binders from various ingredients. The article substantiates the possibility of effectively modifying barium-aluminum binders with waste cobalt catalysts on corundum supports. These circumstances make it possible to justify the choice of raw materials at a qualitative level, and, in combination with calculated data on the geometrostatistical characteristics of the subsolidus structure of the CoO–BaO–Al2O3 system, to obtain technologically important information about the features of dosage and mixing of components when fabricating the binder. The results of this study allow reducing the number of long-duration and labor-intensive experiments to obtain a modified binder with a target set of characteristics.