High Strength Lightweight Insulating Refractory Castable

High-strength lightweight thermal insulation refractory castable (using temperature 900-1200℃), the raw materials used to prepare high-strength lightweight thermal insulation refractory castable mainly include fly ash floating beads, clay porous clinker, lightweight clay bricks, shale ceramsite, clay ceramsite, and aluminum silicate fiber. The binder for preparing high-strength lightweight thermal insulation refractory castable can be calcium aluminate cement or aluminum dihydrogen phosphate. When calcium aluminate cement is used as a binder, a small amount of silica powder can be added. The ratio is roughly 55% to 70% of floating beads, 10% to 20% of lightweight clay bricks, 15% to 25% of calcium aluminate cement, 3% to 5% of silica powder and a small amount of admixtures. The bulk density, compressive strength and thermal conductivity of high-strength lightweight thermal insulation refractory castable also decrease with the increase of the floating bead content in the castable.
High temperature lightweight castable (use temperature＞1200℃), the raw materials for preparing high temperature lightweight castable that can be used above 1200℃ include porous clinker or lightweight waste bricks such as high alumina, mullite, corundum, silicon and magnesium, hollow balls of alumina, zirconia and mullite, chromium or zirconium aluminum silicate fibers, polycrystalline mullite fibers, etc. However, due to the limitation of raw material sources and prices, the current industry still uses more porous clinker of high alumina and mullite, and a small amount of hollow balls of alumina or zirconia, high alumina fibers and alumina fibers for special use requirements. The binders for preparing high temperature lightweight castables include pure calcium aluminate cement, aluminum dihydrogen phosphate, aluminum sulfate and silica sol, etc.