Influence of in situ phase formation on microstructural evolution and properties of castable refractories

The microstructural evolution on firing and quenching two commercial composition castable refractories, a vibratable ultralow cement castable and an in situ spinel low cement castable, was fully characterized and related to high-temperature properties. The emergence of refractory phases such as calcium hexaluminate, magnesium aluminate spinel and mullite was observed to have beneficial effects on hot bend strength and refractoriness under load due to the development of morphologies which interlocked other phases and to pore filling from expansile reactions.