Industrial Preparation of Bauxite-based Mullite Raw Material

Bauxite-based mullite grogs were prepared with grade II bauxite(≤3mm)and coal gangue(≤3mm)as starting materials with formula of w(Al2O3)=68%～72%.Mill the mixture to particle size≤0.044mm by wet milling to homogenize chemical composition. After shaping by wet extrusion and drying, the materials were fired at 1550℃, 1600℃ and 1700℃ for 6 hours respectively. After cooling apparent porosity and bulk density of fired materials were tested. The results show as follows: the appropriate sintering temperature for bauxite-based mullite with homogeneous and consistent composition and microstructure and properties is 1600℃,at which the mullite has apparent porosity≤1.5%,bulk density≥2.81g·cm-3and refractoriness under load is 1610-1650℃.Compared with the laboratory results, the sintering temperature is lowered about 100℃,bulk density increased 0.06g?cm-3.The industrial feasibility of preparing bauxite-based mullite grogs with the processing is confirmed.