关键词: 电熔氧化镁低硅废料, 镁质浇注料, 物理性能, 抗热震性

Abstract: To improve the utilization of low silica fused magnesia waste,magnesia based castables were prepared using fused magnesia,sintered magnesia and low silica fused magnesia waste as main raw materials,replacing sintered magnesia by low silica fused magnesia waste of equivalent particle size (≤75 μm).The effects of the substitution amounts of low silica fused magnesia waste (0,5%,10% and 15%,by mass) on the physical properties and thermal shock resistance of magnesia based castables were investigated.In combination of the microstructure and phase composition,their influence mechanism on the castable properties was analyzed.The results show that:(1)after the heat treatment at 1 550 ℃,with the increasing substitution of low silica fused magnesia waste,the linear shrinkage rate of the castables decreases gradually,the bulk density increases significantly,the apparent porosity shows an obvious downward trend,and the cold compressive strength and strength retention ratio after thermal shock test both increase first and then decrease;(2)when the substitution of low-silica fused magnesia waste is 10%,the magnesia based castables exhibit the optimal comprehensive properties.

Key words: low-silica fused magnesia waste, magnesia-based castables, physical properties, thermal shock resistance