Magnesia Brick
Magnesia bricks are basic refractory bricks made of magnesia as the main component and periclase as the main crystal phase. The content of magnesia is generally more than 90%. Magnesia bricks have high refractoriness and good corrosion resistance to iron oxide, alkaline slag and high calcium flux.
Magnesia bricks are made by crushing magnesia raw materials into granules and powders. After proportioning according to a certain ratio, add binder and knead it into mud, and then burn it through molding, drying, firing and other processes.
Magnesia Brick Performance
- Magnesia bricks have the characteristics of multi-mineral composition, strong alkalinity and high density.
- Magnesia brick is a typical alkaline refractory material, which has a strong ability to resist alkaline slag erosion.
- The melting point of periclase is as high as 2800°C, so the refractoriness of magnesia bricks is also very high, generally above 2000°C. Little practical significance.
- The softening temperature under load varies greatly with the melting point of the cemented phase and the amount of liquid phase produced at high temperature. The load softening temperature of general magnesia bricks is between 1520 and 1600°C, while that of high-purity magnesia bricks can reach 1800°C.
- The linear expansion rate of alkaline bricks is higher than that of other products. At 1000~1600°C, the linear expansion rate of magnesia bricks is generally 1.0%~2.0%, and it is approximately linear. The linear expansion of magnesia-chrome bricks is 1.6% at a minimum of 1600°C.
- Alkaline bricks have high thermal conductivity and poor heat preservation. Among them, magnesia bricks are the highest and magnesia chrome bricks are the lowest.
- The thermal shock resistance of alkaline bricks is not as good as clay bricks and high alumina bricks. The best is magnesia-alumina spinel bricks, and the worst is magnesia bricks. Under 1100″C and water cooling conditions, magnesia bricks are resistant to thermal shock Sex is only 1~2 times.
Magnesia Brick Classification
Magnesia bricks are generally divided into fired magnesia bricks and unfired magnesia bricks.
Unfired magnesia bricks are magnesia carbon bricks, aluminum magnesia carbon bricks, aluminum silicon carbon bricks, magnesium calcium carbon bricks, and carbon free bricks.
The fired magnesia bricks are magnesia chrome bricks, magnesia calcium bricks, magnesia iron bricks, and magnesia aluminum spinel bricks.
Magnesia Brick Manufacturing Process
Unburned brick production process: crushing, compounding, molding, heat treatment, sorting, packaging.
The firing process of fired bricks: crushing, compounding, molding, drying (magnesia-calcium bricks are directly put into the kiln without drying), firing, sorting, processing, sorting, and packaging.
Magnesia Brick Specifications
| Item | MZ-91 | MZ-92 | MZ-93 | MZ-94 | MZ-97 |
|---|---|---|---|---|---|
| MgO,%≥ | 91 | 92 | 93 | 94 | 97 |
| SiO2,%≤ | 4 | 3.5 | 2.5 | 2 | 2 |
| Fe2O3,%≤ | 1.3 | – | – | 1.2 | 1.2 |
| CaO,%≤ | 2.5 | 2.5 | 2 | 1.8 | 1.8 |
| Apparent Porosity,%≤ | 18 | 18 | 18 | 18 | 18 |
| Bulk Density, g/cm3 ≥ | 2.86 | 2.9 | 29.5 | 2.92 | 2.95 |
| Cold Crushing Strength Mpa, ≥ | 60 | 60 | 50 | 60 | 60 |
| 0.2Mpa Refractoriness Under Load T0.6 ℃ | ≥1570 | ≥1560 | ≥1620 | ≥1650 | ≥1700 |
| Thermal Shock Resistances 100 ℃ water cycles | ≥18 | ≥18 | ≥18 | ≥18 | ≥18 |
Magnesia Brick Application
- Steel melting furnace lining, the ferroalloy fiber cable furnace in steel industry.
- Non-ferrous metallurgical industry furnace (such as copper, lead, zinc, tin).
- Building industry kiln, glass kiln, cement kiln, calcination kiln, shaft kiln, tunnel kiln, etc.
