Abstract: A new kind of lightweight alumina-silica castables was investigated,which is expected to be used as a lining material for petrochemical tube furnaces,reducing production costs and promoting the sustainable recycling of refractory raw materials.Lightweight alumina-silica castables were synthesized using closed-pore perlite (4-2 mm),open-pore perlite (8-4 mm) and coal gangue ceramsite (5-2 mm) as aggregates,floating beads (0.5-0.3 mm),sinking beads (0.8-0.6 mm),silica micropowder,α-Al₂O₃ micropowder,zirconia and zircon micropowder as the matrix,Secar 71 as the binder.Effects of the addition of coal gangue ceramsite (0,5%,10%,15%,and 20%,by mass) to replace the same amount of open-pore perlite aggregate on the properties of lightweight alumina-silica castables were studied.The results show that:CaO,MgO,and Na₂O in coal gangue ceramsite can act as sintering agents,which are conducive to the densification of the sample.The appropriate addition of coal gangue ceramsite can also facilitate the generation of CaZr₄O₉,accompanied by the formation of internal microcracks,which can increase the cold compressive strength and thermal shock resistance of the sample.However,the excessive coal gangue ceramsite worsens the hydration effect of the cement and decreases the amount of the bonding phase between aggregates,leading to a decrease in the cold compressive strength.Additionally,the excessive coal gangue ceramsite will also increase the amount of the liquid phase,so the linear shrinkage rate increases.The suitable addition of coal gangue ceramsite is 10%.

Key words: coal gangue ceramsite, open-pore perlite, alumina-silica castables

摘要： 为了研究一种新型轻质铝硅系浇注料,有望作为石油化工管式炉炉衬材料,同时降低生产成本及推进耐火原料可持续循环利用,采用闭孔珍珠岩(4~2 mm)、开孔珍珠岩(8~4 mm)和煤矸石陶粒 (5~2 mm)为骨料,漂珠 (0.5~ 0.3 mm)、沉珠(0.8~0.6 mm)、SiO₂微粉、α-Al₂O₃微粉、氧化锆和锆英石微粉为基质,Secar 71 水泥为结合剂制备了轻质铝硅系浇注料。研究了煤矸石陶粒等量替代(加入质量分数分别为0、5%、10%、15%和20%)开孔珍珠岩骨料对浇注料性能的影响。结果表明:煤矸石陶粒中的CaO、MgO、Na₂O能够起到烧结助剂作用,有利于试样的烧结致密化。适量陶粒加入还有助于反应生成CaZr₄O₉,伴随着内部微裂纹的生成,可以提高试样的常温耐压强度和抗热震性;但过量陶粒加入会导致其水泥水化效果变差,骨料间的结合相减少,故常温耐压强度下降,且会导致液相量的增加,使线收缩率增大。煤矸石陶粒的适宜加入量为10%(w)。

关键词: 煤矸石陶粒, 开孔珍珠岩, 铝硅系浇注料