Bauxite-based mullite grogs were prepared with grade 11 bauxite ( ≤ 3 mm ) and coal gangne ( ≤ 3 mm) as starting materials with formula of w ( Al2O3 ) = 68% - 72 %. Mill the mixture to particle size ≤ 0. 044 ...Bauxite-based mullite grogs were prepared with grade 11 bauxite ( ≤ 3 mm ) and coal gangne ( ≤ 3 mm) as starting materials with formula of w ( Al2O3 ) = 68% - 72 %. Mill the mixture to particle size ≤ 0. 044 mm by wet milling to homogenize chemical composition. After shaping by wet extrusion and drying, the materials were fired at 1 550℃, 1 600℃ and 1 700℃ 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 1 600℃, at which the mullite has apparent porosity ≤ 1.5%, bulk density ≥ 2.81 g · cm^3 and refractoriness under load is 1 610-1 650 ℃. Compared with the laboratory results, the sintering temperature is lowered about 100℃ , bulk density increased 0. 06 g · cm^3. The industrial feasibility of preparing bauxite-based mullite grogs with the processing is confirmed.展开更多
文摘Bauxite-based mullite grogs were prepared with grade 11 bauxite ( ≤ 3 mm ) and coal gangne ( ≤ 3 mm) as starting materials with formula of w ( Al2O3 ) = 68% - 72 %. Mill the mixture to particle size ≤ 0. 044 mm by wet milling to homogenize chemical composition. After shaping by wet extrusion and drying, the materials were fired at 1 550℃, 1 600℃ and 1 700℃ 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 1 600℃, at which the mullite has apparent porosity ≤ 1.5%, bulk density ≥ 2.81 g · cm^3 and refractoriness under load is 1 610-1 650 ℃. Compared with the laboratory results, the sintering temperature is lowered about 100℃ , bulk density increased 0. 06 g · cm^3. The industrial feasibility of preparing bauxite-based mullite grogs with the processing is confirmed.