关键词: 方镁石-镁橄榄石复合骨料, 煅烧温度, 常温耐压强度, 抗热震性

Abstract: To develop a new type of refractory aggregates for tundish lining refractory castables and alleviate the environmental,social,and economic pressures caused by industrial solid waste materials,periclase-forsterite composite aggregates were prepared via the high-temperature solid-state sintering method using fused magnesia powder and silicon cutting waste as the main raw materials and liquid phenolic resin as the binder.The effect of the calcination temperature (1 400,1 500,and 1 600 ℃) on the properties of the samples was investigated.The results show that:(1)with the increasing calcination temperature,the peak intensity of both MgO and Mg₂SiO₄ in the samples increases;the forsterite grains grow continuously and form tight interfacial bonding with periclase grains;the microstructure evolution effectively promotes the overall uniform densification of the samples;meanwhile,the apparent porosity of the samples gradually decreases,the bulk density gradually increases,and the linear shrinkage,volume shrinkage rate,and cold compressive strength all show an upward trend;(2) when the calcination temperature is 1 600 ℃,the samples exhibit the optimal comprehensive properties,with apparent porosity of 3.3%,bulk density of 3.02 g·cm^-3,linear shrinkage of 9.7%,volume shrinkage of 23.0%,cold compressive strength of 178 MPa,and compressive strength retention ratio after thermal shock of 115%.

Key words: periclase-forsterite composite aggregates, calcination temperature, cold compressive strength, thermal shock resistance