LF and Asea-SKF furnace Refractories
LF and Asea-SKF furnace are out furnace refinery equipment, which can further treat converter and EAF smelted steel liquid. Through processing procedures such as adding synthesized slag and alloy, wire feeding, argon blowing and heating, steel liquid can realize deoxidization, desulfurization and non metal material removal. As the working condition of these operations is harsh, furnace lining’s service life will significantly drop. So furnace lining refractories of LF furnace and Asea-SKF furnace should be high grade refractory material. With different operation condition and maintenance method, the service life of furnace lining is generally between 50~100 times. Some LF furnace will have VD refinery, which can greatly shorten furnace lining life. For example, for LF with 70% of VD, the service life of slag line magnesia carbon brick is 18~30 times.
LF Furnace Refractories Physiochemical Index
| Item | MT-1 | MT-2 | MT-3 | MT-4 | LMT-1 | LMT-2 |
| Name | Magnesia carbon brick | Magnesia carbon brick | Magnesia carbon brick | Magnesia carbon brick | Alumina magnesia carbon brick | Alumina magnesia carbon brick |
| Application | Slag line | Slag line, molten bath | Molten bath, free surface | Free surface | Molten bath, bottom | Molten bath, bottom |
| MgO % ≥ | 78 | 82 | 84 | 80 | 12 | 30 |
| Al2O3 %≥ | / | / | / | / | 65 | 50 |
| F.C % ≥ | 14 | 12 | 10 | 8 | 8 | 8 |
| Apparent porosity % ≤ | 4 | 4 | 4 | 7 | 8 | 5 |
| Bulk density g/cm3 ≥ | 2.98 | 3.02 | 3.06 | 2.90 | 2.95 | 3.00 |
| Compression strength Mpa ≥ | 40 | 40 | 40 | 30 | 40 | 40 |
| Hot rupture strength MPa ≥ | 10 | 10 | 10 | 6 | 6 | 6 |
| Item | LMT-3 | LF-m1 | LF-m2 | LF-m3 | LF-B1 | LF-B2 | LF-B3 |
| Name | Magnesia carbon brick | Magnesia ramming mass | Magnesia chrome mortar | Magnesia carbon mortar | Magnesia zirconia carbon sliding plate | Alumina carbon sliding nozzle | Alumina magnesia submerged nozzle |
| Application | Bottom molten bath | Ladle nozzle | Sliding nozzle | Sliding nozzle | Steel liquid flow control | Steel liquid flow control | Steel ladle |
| MgO % | >60 | >90 | / | / | / | / | / |
| Al2O3 % | <20 | / | >80 | ≥65 | ≥70 | >90 | 75.6 |
| F.C % | >8 | / | / | 4.7 | ≥7 | >2 | 4.87 |
| Apparent porosity % ≤ | 6 | 18 | / | / | 2 | 3 | 5.7 |
| Bulk density g/cm3 ≥ | 2.95 | 2.65 | / | / | 3.07 | 3.10 | 2.86 |
| Compression strength Mpa ≥ | 35 | 30 | / | / | 117 | 100 | 105.5 |
| Hot rupture strength MPa ≥ | 6 | / | / | / | 12 | 30 | 15 |
| RUL temperature ℃ | ≥1700 | / | / | / | ≥1700 | / | ≥1700 |
| Item | LF-B4 | LF-B5 | LF-B6 | LF-B7 | LF-B8 | LF-m4 |
| Name | Magnesia spinel sliding plate | Alumina spinel purging plug | Alumina spinel chrome purging plug | Corundum pocket block | Corundum spinel pocket block | High alumina castable |
| Application | Steel liquid flow control | Argon bottom blowing | Argon bottom blowing | Tapping hole and purging plug surrounding | Tapping hole and purging plug surrounding | Permanent lining |
| MgO % ≥ | 80 | 4 | 4 | / | 4 | / |
| Al2O3 % | <20 | >90 | ≥85 | >90 | ≥85 | ≥60 |
| Fe2O3 % | / | / | / | / | / | <1.5 |
| Apparent porosity % | <5 | ≤17 | ≤17 | ≤17 | ≤17 | ≤17 |
| Bulk density g/cm3 ≥ | 3.00 | 3.15 | 3.15 | 3.07 | 3.00 | 2.5 |
| Compression strength Mpa ≥ | 80 | 40 | 40 | 40 | 40 | 60（1400℃,3h） |
| Hot rupture strength MPa ≥ | >20 | >7 | >7 | >5 | >5 | / |
| Item | LF-m5 | LF-m6 | LF-m7 | LF-m8 | LF-m9 |
| Name | Magnesia joint material | Corundum spinel castable | Magnesia mortar | Corundum spinel | Clay brick |
| Application | Steel ladle gap | Impacting plate | Brick masonry | Top blowing and powder gunning machine | Permanent lining |
| MgO % | >90 | >4 | ≥85 | ≥4 | / |
| Al2O3 % | <2 | >90 | / | >87 | ≥40 |
| F.C % ≥ | 14 | 12 | 10 | 8 | 8 |
| Apparent porosity % ≤ | 4 | 4 | 4 | 7 | 8 |
| Bulk density g/cm3 ≥ | 2.98 | 3.02 | 3.06 | 2.90 | 2.95 |
| Compression strength Mpa ≥ | 40 | 40 | 40 | 30 | 40 |
| Hot rupture strength MPa ≥ | 10 | 10 | 10 | 6 | 6 |
