The ternary system ZrO2—MgO—Al2O3 as a whole has not yet been studied. Literature data is available only on binary systems that limit the sides of this ternary system. A study of the fusibility temperatures was carried out along three sections in the ternary system ZrO2—MgO—AlO3 and it was found that in the direction from ZrO2 to the chemical compound MgO - Al2O3 there passes a continuous region of solid solutions, the melting point of which increases depending on the ZrO2 content from 2130° (spinel ) up to 2715 (ZrO2). The absence of eutectic, which causes premature softening of the material, makes these mixtures very important highly refractory.
