Abstract: Lightweight alumina-silica castables were prepared using closed-cell perlite (2-4 mm),open-cell perlite (4-6 mm) and coal gangue ceramsites (≤5 mm) as aggregates,floating beads (0.3-0.5 mm),sinking beads (0.6-0.8 mm),silica micropowder,α-Al₂O₃ micropowder,zirconia and zircon micropowder as fines,and Secar 71 (calcium aluminate cement) cement as the binder.The effects of the coal gangue ceramsites addition (0,6%,12%,18% and 24%,by mass) on the properties of the as-prepared lightweight alumina-silica castables were investigated.The results show that:(1)the addition of coal gangue ceramsites can reduce the sintering shrinkage of the specimens and help to improve the strength and thermal shock resistance;(2)the specimens with the addition of coal gangue ceramsites can produce pores in the matrix of the sintered specimens,which provides enough space for the growth of CA₆ complex solid solution and expands the irregular lamellar structure;(3)with the addition of coal gangue ceramsites increasing,the linear shrinkage of the specimens sintered at 1 000 or 1 200 ℃ firstly reduces and then increases,the bulk density increases and the apparent porosity decreases;the cold compression strength and the thermal shock resistance of the specimens sintered at 1 200 ℃ firstly increase and then decrease.Thus,the optimal addition of coal gangue ceramsites is 18%.

Key words: alumina-silica castables, closed-cell perlite, coal gangue ceramsites, comprehensive performance

摘要： 采用闭孔珍珠岩(粒度为2~4 mm)、开孔珍珠岩(粒度4~6 mm)和煤矸石陶粒(≤5 mm)为骨料,漂珠(0.3~0.5 mm)、沉珠(0.6~0.8 mm)、SiO₂微粉、α-Al₂O₃微粉、氧化锆和锆英石微粉为细粉,Secar 71水泥(铝酸钙水泥)为结合剂制备了轻质铝硅系浇注料,研究了煤矸石陶粒加入量(加入质量分数分别为0、6%、12%、18%和24%)对制备轻质铝硅系浇注料性能的影响。结果表明:1)煤矸石陶粒的加入能降低试样的烧结收缩,提高其强度和抗热震性;2)加入煤矸石陶粒后的试样经过烧结后能够在基质中产生孔隙,为CA₆复杂固溶体的生长提供足够空间,使不规则片状结构得到扩展;3)随着煤矸石陶粒加入量的增加,经1 000和1 200 ℃烧后试样的线收缩率先减小后增加,体积密度增加,显气孔率降低,经1 200 ℃烧后试样的常温耐压强度、抗热震性先增大后减小。综上,煤矸石陶粒适宜加入量为18%(w)。

关键词: 铝硅系浇注料, 闭孔珍珠岩, 煤矸石陶粒, 综合性能