Mullite Castable
Mullite castable is refractory mix made by mullite aggregate and fines, binders and additives. The max. granularity of mullite aggregate is 12mm. Different bulk density mullite castable can be produced by reasonably adjusting mullite granularity formulation. Pure calcium aluminate cement is usually used as binder of mullite castable, so the refractoriness and high temperature strength of mullite castable can be promised. In order to improve the strength and abrasion resistance of mullite castable, micro silica powder can replace part of calcium aluminate cement. The max. working temperature of mullite castable is about 1450~1600℃, it is widely used as working lining and burner nozzle of various kinds of heat treatment furnace, electric furnace tapping spout, shaft lime kiln high temperature zone, rotary kiln hood, power plant boiler working lining, etc.
Mullite Castable Advantages
Mullite castable has high working temperature, the working lining can directly contact with flame.
Low bulk density, structure weight is greatly reduced.
Mullite castable has good thermal shock resistance, good spalling resistance.
Mullite castable has good workability, the work period is short, economic effect is significant.
The thermal conductivity is relatively low, thermal efficiency is high.
The lining service lifer is long.
Mullite Castable Physiochemical Index
| Item |
High alumina |
| Al2O3 % |
76 |
| SiO2 % |
21 |
| CaO % |
<1.5 |
| Bulk Density(110℃, 24h) g/cm3 |
2.61 |
| Cold crushing strength(1350℃, 3h) Mpa |
115 |
| Linear change rate(1350℃, 3h) % |
±0.5 |
| Max working temperature ℃ |
1600 |
| Water needed % |
6.0~6.5 |
Mullite Castable Application
Mullite castable is widely used in circulating fluidized bed boiler water cooling wind chamber, insulating wind chamber. It is also widely used in petrochemical industry tube heating furnace, light diesel, ethane cracking furnace lining, sulfur recovery equipment, steam boiler, tube insulating layer, furnace door of other industrial furnaces, kiln eyes, inspection hole inner lining and so on. Besides, premium light mullite aggregate can be used to make light mullite castable, it can be directly used at high temperature parts of heating furnaces.
When corundum is added into mullite castable, it has the characteristics of corundum, such as stripping resistance, abrasion resistance, acid media corrosion resistance. So corundum mullite castable has better crushing strength, wear resistance and corrosion resistance than mullite castable. Corundum mullite castable is widely used in large size power plant boiler wear resistant lining and other high temperature kilns working lining.
