unshaped refractory
Lightweight Insulating Castable
Lightweight insulating castable is a heat-insulating refractory castable using lightweight high alumina, perlite, ceramsite, cenospheres and mullite hollow spheres as aggregates with low-cement bonding. It features light weight and low thermal conductivity and mainly provides thermal insulation; it is not used as a working layer in direct contact with high-temperature flame, and is mostly used as a backing insulation layer of kiln linings to reduce outward heat loss, lower furnace-shell temperature and save fuel.
| Grade | Al₂O₃ Content | Long-term Service Temp. | Typical Applications |
| QG50 | ≥45-70% | 900-1350℃ | Backing of heating furnaces, insulation layers of boiler furnace walls, outer layers of flues, kiln insulation layers, insulation layers of heat-treatment furnaces, thermal insulation layers of hot blast stoves; not to be used on working surfaces directly exposed to scouring, abrasion or direct flame. |