Influence of Iron Oxides on Red Mud Based Ceramic Tiles

Red mud based ceramic tiles were successfully fabricated by high-temperature sintering and the influence of the Fe2O3 content on their comprehensive performance, mineral phase, and microstructure were systematically investigated. The results indicate that iron is involved in the structural reorganization of mullite during the nucleating process. Adding 9% Fe2O3 elongated mullite crystals to an aspect ratio of 15.6 ± 2.1, and the crystals were successfully obtained at a sintering temperature of 1300°C for 2 h. In this case, the values for water absorption and compressive strength of the red mud based ceramics were 6.6% and 178.3 MPa, respectively, reaching the national standard for building materials. Putting the right amount of Fe2O3 into ceramics can not only promote the anisotropic growth of mullite crystals but can result in the formation of an interlocked network of mullite at lower temperatures. This work will contribute to a better understanding of the influence of Fe2O3 on basic material performance, such as structural, micro-analysis, and mechanical characteristics of ceramic tiles with iron-containing mullites.