Precast blocks for EAF roof is made by steel fibre reinforced ultra-low cement castables with corundum, spinel and mullite as the main materials, and characterized with high strength, good thermal shock resistance, good erosion resistance and long service life.
| Product code | CH-DSY80 | CH-DSY85 | CH-DSY90 | CH-DSY92 |
| Al2O3MgO/% | 80 | 85 | 90 | 90 |
| Cr2O3/% | ---- | ---- | ---- | 2 |
| Bulk density/gcm3 | 2.75 (110°C , 24h) | 2.90 (110°C , 24h) | 3.05 (110°C , 24h) | 3.05 (110°C , 24h) |
| Cold crushing strength/ MPa | 40 (110°C , 24h) | 40 (110°C , 24h) | 40 (110°C , 24h) | 40 (110°C , 24h) |
| 60 (110°C , 24h) | 60 (110°C , 24h) | 60 (110°C , 24h) | 60 (110°C , 24h) | |
| Permanentlinear change/% | 0 .5 (1500°C,3h) | 0 .5 (1500°C,3h) | 0 .5 (1500°C,3h) | 0 .5 (1500°C,3h) |


