Brief Description
Wear Resistant Castable is unshaped refractory, which can resist high temperature solid material or solid powder containing airflow abrasion or fluxing.
High strength abrasion resistant castable is mainly used as the working lining of high temperature cyclone separator, circulating fluidized bed and as the tapping spout lining of heating furnace. The modulus of rupture and crushing strength of this kind of castable are very high, that’s why it is called high strength refractory castable.
Abrasion resistant castable is composed of high hardness refractory aggregate, powder, high strength binder and additives. High hardness aggregate includes: fused corundum(white corundum, brown corundum and so on), fused zirconia corundum, fused mullite sintered high alumina bauxite, fused high alumina or clay material, silicon carbide and so on, which one or which combination should be chosen depends on actual working conditions.
Physiochemical Index
| Item | NM-1 | NM-2 | NM-3 | NM-4 |
| Al2O3 % ≥ | 70 | 75 | 80 | 85 |
| CaO % ≤ | 2.5 | 2.5 | 2.5 | 2.5 |
| Bulk density g/cm3 > | 2.6 | 2.75 | 2.8 | 2.9 |
| Crushing strength Mpa(1400℃, 3h) | >90 | >95 | >105 | >110 |
| Modulus of rupture Mpa(1400℃, 3h) | >13.0 | >13.5 | >15.0 | >16.0 |
| Room temperature abrasion loss cm3 | <9.6 | <8.5 | <7.3 | <6 |
| 0.2MPa, refractoriness under load beginning temperature ℃ | >1450 | >1490 | >1530 | >1560 |
| Thermal shock resistance(900℃, water cooling)/times | >20 | >20 | >20 | >20 |
| Max. working temperature ℃ | 1550 | 1550 | 1600 | 1600 |
| Reheating linear change rate % | <-0.3 | <-0.3 | <-0.2 | <-0.2 |
Application
Wear Resistant Castable used for power plant circulating fluidized bed boiler is usually made by sintered high alumina bauxite and fused corundum, sometimes, black silicon carbide is added into it, high purity calcium aluminate cement added with silica micro powder is usually used as binder.
Wear Resistant Castableused in alumina suspension roasting furnace is similar to that of circulating fluidized bed boiler, but there is no silicon carbide in the ingredients. The high strength abrasion resistant castable used in petrol refining catalytic cracking equipment adopts fused or sintered white corundum (or tabular alumina ) as aggregate, high purity calcium aluminate (added with reactive alumina) is used binding agent. Fe2O3 content in high strength abrasion resistant castable should be less than 0.05%.
Wear Resistant Castable used in heating furnace tapping spout are composed of fused corundum( brown corundum or sub-white corundum) aggregate, fused corundum powder, a-Al2O3 micro powder, SiO2 micro powder, Cr2O3 micro powder( or zircon micro powder) and high purity calcium aluminate cement. When the castable is prepared, it need to be made into precast block and sintered at high temperature(above 1500℃) before using. When certain amount of SiC is added into the raw material of these kinds of castable, it can used to precast heating furnace slideway brick, which has good high temperature abrasion resistance.