Electric Arc Furnace Wall Refractory Material Description
For small size electric arc furnaces, low price and low grade refractory materials such as pitch bound magnesia bricks, low grade magnesia carbon bricks and magnesia sand patching material are usually used, those refractories have short service life and large unit consumption. Modified pitch series resin bonded magnesia carbon bricks has similar performance with phenolic resin bound magnesia carbon bricks. The service life of small size electric arc furnace is between 40~120 times, but when high quality refractory materials are used and the linings are timely patched, the service life of small size electric furnace can reach to 150 times or more, unit refractory material consumption can decrease to less than 6kg.
For ultra high power electric furnaces, furnace walls usually adopts superior quality magnesia carbon bricks, especially for slag line and hot point, special grade magnesia carbon bricks should be used. Meanwhile, to prolong furnace’s service life, furnace lining should be regularly maintained by gunning mix, furnace lining gunning patching is an important method for prolonging furnace lining’s service life. Through patching, the service life of ultra high powder electric furnace lining can reach to more than 1000 times. The unit consumption of furnace lining magnesia carbon bricks is lower than 0.2kg. The main consumable refractory material of electric furnace is magnesia gunning mix.
Electric Furnace Wall Refractory Materials Physiochemical Index
| Item | Magnesia % | C % | Bulk density g/cm3 | RUL ℃ | Compression strength MPa | Application |
| Pitch bind magnesia carbon bricks | >80 | 5 | 2.90 | 1700 | >40 | Except for slag line |
| Pitch bind magnesia carbon bricks | 85 | 14 | 3.00 | >1750 | >30 | Slag line, hot point |
| Phenolic resin magnesia brick | 80 | <1.5 | 3.00 | / | >40 | Slag line, hot point |
| Burned magnesia bricks | 91 | / | 3.05 | / | 58.0 | Permanent layer |
| Magnesia carbon bricks | 82 | 10 | 3.02 | 1750 | >35 | Slag line |
| Magnesia gunning mix | 83 | / | / | 1750 | / | Slag line |
| Magnesia carbon gunning mix | 80 | 5 | / | 1700 | / | Slag line |
| Magnesia carbon bricks | >85 | >5 | >2.95 | / | >30 | Below slag line |
| Magnesia ramming mass | >90 | / | 2.70 | / | / | Upper part, joint material |
For the smelting of some ultra low carbon steel, and stainless steel, there is strict control of carbon content. To avoid carbon increase in steel, magnesia carbon bricks and other carbon containing refractory materials should not be used. Magnesia bricks, magnesia ramming mix and magnesia chrome refractory materials are a better choice for the construction of furnace linings.
