It is used in the lining and roof of metallurgical equipment such as blast furnaces, converters, electric furnaces, and ladles.
Magnesia spinel brick is a kind of basic refractory brick, which is a composite material mainly made of magnesia (MgO) and spinel (MgAl2O4) or spinel and iron (MgFe2O4). Magnesia spinel bricks include fired and unfired. Magnesia spinel bricks have high bulk density, uniform structure, thermal stability, corrosion resistance, and high mechanical strength, which can extend the life of lining on a large scale and are widely used in steel smelting, cement production, and glass manufacturing, where the temperature can reach thousands of degrees Celsius, and also has environmental performance will not produce harmful substances.
氧化镁氧化铝尖晶石砖
| Item | Index | |
|---|---|---|
| ω（氧化镁）/% | μ0 ≥ | 80 |
| ω (Al2O3)/% | μ0 ≥ | 10 |
| 表观孔隙率/% | μ0 ≤ | 17 |
| ở | 0.8 | |
| Bulk Density (g/cm³) | μ0 ≥ | 2.90 |
| ở | 0.03 | |
| 冷压强度/兆帕 | L ≥ | 50 |
| ở | 5 | |
| Permanent Linear Change (1500℃*2h)/% | L~U | 0~+0.3 |
| ở | 0.05 | |
| High-temperature Bending Strength (1350℃*0.5h)/MPa | μ0 ≥ | 3.5 |
| ở | 0.6 | |
| Thermal Shock Resistances (1100℃, Water Cooling)/Cycle | μ0 ≥ | 12 |
| ở | 2 | |
氧化镁铁尖晶石砖
| 项目/等级 | MFe-85A | MFe-85B |
|---|---|---|
| ω (MgO) ≥/% | 85 | 85 |
| ω (Al2O3)/% | 3-5 | 3-5 |
| ω (Fe2O3)/% | 4-6 | 4-6 |
| Bulk Density ≥ (g/cm³) | 2.95 | 2.90 |
| Cold Crushing Strength ≥ (MPa) | 55 | 50 |
| Refractoriness Underload ≥ (T0.6℃) | 1650 | 1600 |
| Thermal Shock Resistance ≥ (950℃ Air Quenching, Cycle) | 100 | 90 |
| Thermal Conductivity ≤ (1000℃) [W/(m·K)] | 2.6 | 2.6 |
| Thermal Expansion Coefficient (1400℃)/% | 1.6 | 1.6 |
1.Anti-Corrosion And Anti-Stripping 2.Good Thermal Shock Stability 3.Lower Thermal Conductivity 4.Good Electrical Insulation Properties
Magnesia spinel bricks usually include magnesia alumina spinel bricks and magnesia iron spinel bricks
Magnesia spinel bricks containing a certain proportion of alumina are also called magnesia alumina spinel bricks, with a structure of MgAl2O4 or MgO·Al2O3. magnesia alumina spinel brick not only has high hardness, low thermal expansion coefficient, and high density, but also has the advantages of quenching resistance and rapid heating, and has good corrosion resistance to solvents such as iron oxide and alkali slag.
Magnesia iron spinel refractory bricks are made of high-purity magnesia and aluminum-iron spinel as raw materials. During the use of magnesia-iron spinel bricks, a layer of highly viscous calcium-iron and calcium-iron-aluminum compounds is formed on the hot surface of the bricks, which is easy to hang in the kiln. The product has the characteristics of high compressive strength and good thermal shock resistance. The characteristics can effectively solve the problem of causing pollution to the environment by generating hexavalent chromium during the use of magnesia chrome bricks for cement kilns. Magnesia-iron spinel bricks are highly regarded for their excellent thermal stability. Its erosion resistance is better than that of high-quality magnesite chrome bricks.
Magnesia – spinel bricks are extensively used in the steel industry. They line the linings of converters, protecting against molten steel and slag corrosion. In electric arc furnaces, they endure arc impacts and temperature fluctuations. Also, they’re applied in ladles, safeguarding against steel – water erosion for stable operations.