In this study the construction of a phase tree and the description of the chemical interaction for the ternary oxide system CaO-Al2 O3 -SiO2 are given. Particular interest to a system consisting of oxides of calcium, aluminum and silicon is associated with the production of highly demanded functional materials with desired properties. Melts of the CaO-Al2 O3 -SiO2 system are of great theoretical and applied importance. This is due to the signifi cant role of melts of these oxides and their mixtures in metallurgy, ceramics production, and other industries.
