Effect of Iron Ore Powder Addition on the Structure and Properties of Second-Grade Bauxite-Based Ceramics

High-strength bauxite-based ceramic material was successfully prepared by using second-grade bauxite with the addition of iron ore powder and manganese ore powder. By controlling the amount of iron ore powder added to the ceramic system, this study successfully promoted the completion of the secondary mullite reaction process. The content of the liquid phase in the material sintering process is regulated. Therefore, a large number of pores can be discharged after cooling. Finally, a high-strength bauxite-based ceramic material was prepared by adjusting the morphology of mullite whiskers. The effect of iron ore powder on the microstructure and properties of bauxite-based ceramics were studied. The phase compositions and microstructures were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The fracture mechanism and sintering behavior of bauxite-based ceramics were preliminarily analyzed. The flexural strength, density, and water absorption of ceramics as functions of iron ore powder contents were systematically investigated. When additions of iron ore powder were 2 wt%, bauxite-based ceramic performances of flexural strength has reached a maximum of 195.87 MPa. High strength corundum ceramics from bauxite are important to broaden the application fields of bauxite-based ceramics. The use of second-grade bauxite to prepare high-strength ceramic materials is of great significance for expanding the application fields of bauxite resources.