关键词: 铝锆碳耐火材料, 混料工艺, 常温耐压强度, 显微结构

Abstract: Aiming at the regulation and optimization of microstructure and mechanical properties of Al₂O₃-ZrO₂-C refractories green bodies,Al₂O₃-ZrO₂-C refractory samples and their matrix samples were prepared by mechanical compression molding with the tabular corundum,zircon mullite and zircon corundum as aggregates,the α-Al₂O₃ micropowder,flake graphite and additives as fine powders,and the lignosulfonate as the binder.Influences of different fine powder mixing processes (0.5 h manual mixing,no mixing,2 h ball milling,and 5 h ball milling) on the bulk density,apparent porosity,cold compressive strength,and microstructure were investigated.The results indicate that the fine powder mixing process has minimal impact on the apparent porosity and bulk density,but it significantly affects the microstructure and cold compression strength.Ball milling ensures an even distribution of raw materials while reducing defects such as pores and cracks;it also enhances particle size uniformity and the specific surface area of matrix raw materials,which facilitates the adsorption and bonding with lignosulfonate solution,thereby obviously improving the strength.However,excessive ball milling may result in excessively fine particles or increased agglomeration,reducing the strength.When the fine powder is mixed by ball milling for 2 h,an optimal combination between the matrix components and the aggregates is achieved,resulting in the highest cold compressive strength.

Key words: Al₂O₃-ZrO₂-C refractories, mixing process, cold compressive strength, microstructure