关键词: 煤矸石陶粒, 开孔珍珠岩, 铝硅系浇注料

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