Refractories, dynamic composites

The description of metallurgical refractories as dynamic composites is addressed through their continuously changing structure during applications in steel processing vessel linings. Two distinct types of composite refractories are considered: the magnesia-carbon refractories used for the linings of basic oxygen steelmaking vessels and the alumina-magnesia-carbon refractories for the linings of ladles. For each example, different dynamic chemical reactions govern the successful application of these sophisticated modern composites. In the former it is the continuous formation of a dense oxide zone at the refractory hot face. For the latter, it is the chemical reaction of the two oxides, magnesia and alumina to form magnesium aluminate spinel within the refractory structure. The spinel formation reaction has an accompanying volume expansion which imparts to the refractory the ability to seal cracks and continually tighten the refractory lining within the process vessel during the lifetime of the lining. In both instances significant increases in the specific process vessel refractory lining campaigns have been achieved. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd