Brief Introduction
Magnesia Chrome Brick is a kind of basic refractory material with more than 90% magnesium oxide content and periclase as the main crystal phase, which has excellent properties of high refractoriness, high temperature strength, good thermal shock resistance and strong basic slag erosion resistance and is mainly used for steelmaking basic open-hearth furnace, electric furnace bottom and wall, permanent lining of oxygen converter, non-ferrous metal metallurgy furnace, high-temperature tunnel kiln, lining of rotary kiln, furnace bottom and wall of heating furnace, regenerative chamber of glass furnace and etc.
For the Magnesia Chrome Brick, the maximum allowed environment temperature is 1700℃. It has features of high strength, high refractoriness under load, high alkali erosion resistance and high thermal shock resistance under the load conditions of 1500~1650℃ and also have big advantages of environmental protection and long service life.
Performance
(1) High temperature volume stability & strong slag resistance
(2) Highly refractory temperature, the refractory temperature is greater than 2000°C, and 1550-1600°C for the firing temperature .
(3) The load softening temperature is greater than 1550°C at a constant pressure of 0.2mpa.
(4) Excellent thermal shock resistance, resistance to quenching and rapid thermal performance than magnesium bricks.
Classification
Common Magnesia Chrome Brick
It is made from sintered magnesia and chrome ore, and sintered at high temperature, which is with higher bulk density and stronger thermal resistance than the magnesite brick, widely used in cement rotary kilns, glass kiln regenerators, permanent lining of steel furnace, and permanent lining of refining ladle.
Direct Bonded Magnesia-Chrome Brick
It is made from high purity magnesia and chromite materials and sintered under the high temperature in the tunnel kiln, it’s widely used in the lining of the RH/DH vessel , cement rotary kiln, glass tank furnace, non-ferrous metal metallurgical furnace, AOD, VOD furnaces, etc.
Re-Bonded Magnesia- Chrome Brick
It is made from fully electro-fused MgO-Cr2O3 grain, and fired under more than 1700 ° C with weak oxidizing atmosphere. It’s a high quality Magnesia Chrome product with excellent strength & volume stability at high temperature, excellent slag corrosion resistance and erosion resistance; widely used in second-refining furnance, like slag line of VOD and AOD, RH/DH’s snorkels and regenerators of glass kiln ,etc.
Semi-Re-Bonded Magnesia-Chrome Brick
It is made from electro fused MgO-Cr2O3 grain, fused magnesia, chromite and some sintered MgO-Cr2O3 grain, then fired at high temperature. It has some characteristics both direct bonded and re-bonded, like dense inner structure, lower porosity, good high temperature strength, thermal shock resistance is better than re-bonded, slag erosion resistance better than direct bonded. It can be used in sidewall of EAF, DH/RH degasser, VOD, LF, AOD’s side wall/bottom or free board and some serious parts like slag line, regenerators of glass furnace, etc.
Commom Magnesia Chorme Brick
Direct-Bonded Magnesia Chrome
Rebonded Magnesia Chrome Brick
Technical Datas
| Item | Commom Magnesia Chrome Brick | Direct-Bonded Magnesia Chrome Brick | ||||||
| Model | MGe6 | MGe8 | MGe12 | MGe16 | DMGe4 | DMGe8 | DMGe12 | DMGe16 |
| MgO % | 80 | 72 | 70 | 65 | 85 | 77 | 74 | 69 |
| Cr2O3 % | 7 | 10 | 13 | 17 | 5.5 | 9.1 | 14 | 18 |
| CaO % | 1.2 | 1.2 | 1.2 | 1.2 | 1.1 | 1.4 | 1.2 | 1.2 |
| SiO2 % | 3.4 | 4 | 4 | 4.2 | 1.3 | 1.2 | 1.2 | 1.5 |
| Al2O3 % | 4.5 | 6.5 | 6 | 6 | 3.5 | 4 | 3.5 | 4.5 |
| Fe2O3 % | 4 | 4.8 | 5.5 | 6.5 | 3 | 6.4 | 5 | 5.7 |
| Apparent Porosity % | 17 | 18 | 18 | 18 | 18 | 18 | 18 | 18 |
| Bulk Density g/cm3 | 3 | 3 | 3.02 | 3.05 | 3.02 | 3.04 | 3.06 | 3.08 |
| Cold Crushing Strength Mpa | 55 | 55 | 55 | 50 | 50 | 50 | 55 | 55 |
| Refractoriness Under Load °C | 1600 | 1600 | 1600 | 1600 | 1700 | 1700 | 1700 | 1700 |
| Thermal expansion % 1000°C | / | / | / | / | 1 | 1 | 1 | 0.9 |
| Thermal expansion % 1600°C | / | / | / | / | 1.8 | 1.8 | 1.8 | 1.6 |
| Item | Fused Semi-rebond Magnesia Chrome Brick | Fused Rebonded Magnesia Chrome Brick | |||||
| Model | SRMGe-16 | SRMGe-18 | SRMGe-20 | SRMGe-22 | SRMGe-26 | RMGe-12 | RMGe-14 |
| MgO % | 68 | 64 | 65 | 56 | 56 | 75 | 75 |
| Cr2O3 % | 16 | 18 | 20 | 22 | 26 | 12 | 14 |
| SiO2 % | 1.5 | 1.5 | 1 | 2.5 | 2.5 | 1.5 | 1.5 |
| Apparent Porosity % | 16 | 16 | 14 | 16 | 16 | 15 | 15 |
| Bulk Density g/cm3 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.2 | 3.2 |
| Cold Crushing Strength Mpa | 40 | 40 | 40 | 40 | 40 | 50 | 50 |
| Refractoriness Under Load °C | 1700 | 1700 | 1700 | 1700 | 1700 | 1700 | 1700 |
Application
1). Magnesia Chrome Brick is mainly used in metallurgical industry, such as for building open-hearth furnace top, electric furnace top, finery out of furnace and all kinds of non-ferrous metal metallurgy furnace.
2). Fused cast magnesite chrome brick is adopted for high temperature position of furnace wall in electric furnace with ultra high power.
3). Magnesia chrome brick that made of synthetic compost is adopted for strong erosion area in finery out of furnace.
4). Fused cast magnesite chrome brick or magnesia chrome brick that made of synthetic compost is adopted for strong erosion area of nonferrous metals flash smelting furnace.
5). Besides, Magnesia Chrome Brick also can be used for burning zone in rotary cement kiln and regenerative chamber in glass furnace.
