Corundum-spinel refractories

Conclusions

The production technology of corundum-spinel refractories may be varied. The corundum fireclay and spinel compositions of the batch and the granular composition of the body may be varied considerably. The corundum can be fired at 1580–1750°C, the spinel can be synthesized at 1400–1750°C, and also unfired granules of a stoichiometric spinel composition can be used. Finely ground alumina can be added to the fired or unfired material and to a mixture of the two. The maximum firing temperature of the refractories is 1580–1750°C. Selection of the actual parameters of the technological process is dependent on the required properties of the refractories, which are determined by the conditions of service.

The formation of a two-phase, rather mobile structure as a result of adding magnesium spinel to a corundum refractory, and of adding a small amount of magnesium oxide to the binder, ensures a considerable increase in the thermal stability of corundum-spinel refractory products.