Sintering, mechanical and refractory properties of MA spinel prepared via co-precipitation and sol-gel techniques

This work aims to study and improve the sintering, mechanical and refractory properties of magnesium aluminate spinel, magnesia-spinel and alumina-spinet refractory bodies through addition of chromia, zirconia or their mixtures. Magnesium nitrate and aluminum nitrate were used to prepare magnesium aluminate spinel (MA) via a co-precipitation technique while aluminum hydroxide and magnesium chloride were used to prepare magnesium aluminate spinel (MA) via sot-gel technique. Zirconia and chromia were used as additives to the prepared spinet samples. The sintering parameters, mechanical properties as well as refractory properties were tested according to the international standard specifications. Alumina-spinel compositions exhibited the best sintering and mechanical properties while magnesia-spinel ones exposed the best refractory behavior. Addition of chromia or zirconia accomplished a pronounced improvement in sintering, mechanical and refractory properties. However, the addition of a mixture of chromia/zirconia exhibited the best of such properties. (C) 2010 Elsevier B.V. All rights reserved.