Insulating Castables (Medium Purity)
Refralite are a range of insulating castables to conserve heat in furnaces. They are light but strong and have low conductivity, serve as either hot face or back up insulating refractory lining.
These castables are produced in density range of 400 to 1600 kg/m3. They are available mainly in two different grades – medium purity and high purity. The high purity (Low Iron) variety is suitable for reducing environments.
| BRANDS | Refralite - 4 | Refralite - 7 | Refralite - 9 | Refralite - 11 | Refralite - 13 | Refralite - 15 |
| Chemical Analysis | ||||||
| Al2O3% Min. | 30 | 33 | 33 | 34 | 39 | 39 |
| Fe2O3% Max. | 11 | 8.5 | 6 | 3.5 | 3.5 | 3.2 |
| Physical Properties | ||||||
| Service Temp. ˚C | 1000 | 1100 | 1100 | 1300 | 1350 | 1350 |
| Bulk Density gms/cc | 0.55 | 0.85 | 1.00 | 1.25 | 1.45 | 1.60 |
| Water required for casting% | 80 - 100 | 60 - 65 | 38 - 43 | 29 - 34 | 26 - 31 | 23 - 28 |
| Grain Size, mm | 6 | 6 | 6 | 6 | 6 | 6 |
| CCS Kgs/cm2 | ||||||
| At 110 ˚C/24 hrs. | 4 | 12 | 15 | 35 | 50 | 90 |
| At 800 ˚C/3 hrs. | 2 | 4 | 6 | 25 | 30 | 60 |
| At 1100 ˚C/3 hrs. | - | 6 | - | 25 | 30 | 60 |
| At 1300 ˚C/3 hrs. | 40 | 50 | 70 | |||
| Thermal Properties | ||||||
| PLC% @ 800˚C/3 hrs. | + 0.4 | + 0.8 | + 0.6 | + 0.3 | + 0.2 | + 0.2 |
| Heating at 1000˚C/3 hrs. | + 0.6 | + 1.20 | ||||
| Heating at 1200˚C/3 hrs. | + 1.0 | |||||
| Heating at 1300˚C/3 hrs. | + 1.0 | + 0.8 | + 1.0 | |||
| Thermal Conductivity Kcal/m/hr/˚C | ||||||
| At 300 ˚C HF | 0.07 | 0.15 | 0.24 | 0.27 | 0.30 | 0.39 |
| At 500 ˚C HF | 0.09 | 0.17 | 0.26 | 0.30 | 0.32 | 0.42 |
| At 800 ˚C HF | 0.12 | 0.19 | 0.28 | 0.32 | 0.35 | 0.45 |
