Spinel-based refractories for improved performance in coal gasification environments

Oak Ridge National Laboratory, in collaboration with Minteq International, Inc., Missouri University of Science and Technology and refractory end users, has developed novel refractory systems and techniques to reduce energy consumption of refractory lined vessels. The objective of this U.S. DOE funded project was to address the need for innovative refractory compositions by developing MgO-Al₂0₃ spinel gunnable refractory compositions utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques. Materials have been developed specifically for coal gasification environments and work has been performed to develop and apply low cost coatings using a colloidal approach for protection against attack of the refractory brick by the service environment and to develop a light-weight back-up refractory system to help offset the high thermal conductivity inherent in spinel materials. This paper discusses the systematic development of these materials, laboratory testing and evaluation of these materials, and relevant results achieved toward the reduction of chemical reactions and mechanical degradation by the service environment though compositional and processing modifications.