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

摘要： 为了开发一种用于中间包内衬耐火浇注料的新型耐火骨料,同时缓解工业固废材料对环境、社会和经济产生的压力,以电熔氧化镁粉和硅切割废料为主要原料,液体酚醛树脂作为结合剂,采用高温固相烧结法制备方镁石-镁橄榄石复合骨料,研究了煅烧温度(分别为1 400、1 500和1 600 ℃)对试样性能的影响。结果表明:1)随着煅烧温度的不断升高,试样中的MgO(方镁石)和Mg₂SiO₄(镁橄榄石)的峰强均增强,镁橄榄石晶粒不断生长,且其与方镁石晶粒之间形成紧密的界面连接,这种微观结构的演化有效推动了试样整体的均匀致密化进程;试样的显气孔率逐渐下降,体积密度逐渐上升,线收缩率和体积收缩率以及常温耐压强度均呈现上升趋势。2)当煅烧温度为1 600 ℃时,试样的综合性能最佳,其显气孔率为3.3%,体积密度为3.02 g·cm^-3,线收缩率为 9.7%,体积收缩率为23.0%,常温耐压强度为178 MPa,热震后的耐压强度保持率为115%。

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