Formation of a Spinel/Forsterite Refractory Aggregate from Sillimanite

摘要

Sillimanite was milled, combined with MgO and then fired to form spinel/forsterite composite refractory aggregates. Ball milling and attrition milling were both studied. Both milling methods produced dense spinel/forsterite aggregates suitable for refractory applications. Although the free decomposition of sillimanite produces mullite and silica, neither was observed by X-ray diffraction after firing. Sillimanite does not experience a distinct and separate decomposition prior to reactions with periclase to form spinel and forsterite. A significant fraction of the sillimanite appears to directly react with the magnesia producing spinel and forsterite.