Phase Equilibria in the System MgO‐Cr ² O ³ ‐SiO ₂

Abstract

Studies of phase equilibria by the method of quenching show that there are no ternary compounds at liquidus temperatures in the system MgO‐Cr 2 O 3 ‐SiO 2 . There is an extensive two‐liquid region, and the stability fields of periclase, picrochromite, and chromic oxide extend across most of the diagram. Temperatures of liquid formation are sufficiently high that a number of different compositions can be suggested for refractory purposes. Fundamental explanations are brought out for the improvement of chromite and chromite‐forsterite refractories by the addition of MgO and for the improvement of chromite‐silica refractories by the addition of chromic oxide or some other high‐chromium compound.