Characterization of a Red Mud and a Clay Body for Ceramic Fabrication

Red mud is a specific term applied for a residue generated during the processing of aluminum ores, mainly bauxite in the Bayer process, to produce alumina (Al2O3). In several countries where bauxite is mined and processed, distinct red muds are generated in ever growing amounts and becoming an environmental problem. This problem is also affecting the large bauxite processing plants in Brazil and a possible solution for the red mud is its addition to clay ceramics. Before an industrial scale addition is implanted, the specific red mud needs to be characterized for compatible behavior with the ceramic clay matrix. Therefore, the objective of the present work was to characterize a red mud generated in Brazil for an eventual addition to clay ceramic. This was conducted through the determination of density, chemical and mineralogical composition as well as size distribution and microscopic observation of particles. The results indicated that the specific red mud investigated is compatible with clays and has a potential for addition in common red ceramics.