Magnesia Carbon brick is a resin-bonded basic refractory brick made from de ad-burned (sintered) or fused magnesia and graphite and bonded with high ca rbon containing pitch and resin, with some metallic powder as anti-oxidants to protect the carbon. Magnesia-Carbon bricks have many advantages over th e conventional alumina brick lining.
Between 1975 and 1980 magnesia-carbon refractories were developed and start ed to be used in Japan first for electric arc furnace hot spots and shortly thereafter for BOFs.
The magnesia carbon brick is produced by adding a carbon-bonding formative agent to dead-burned (sintered) or fused magnesia and graphite, which are t hen pressed by the usual method and then subjected to heat treatment. It re places pitch with resin and allows for a dramatic increase in the carbon le vel as a result of graphite additions. Subsequently, antioxidants are added to the magnesia-carbon brick to protect the carbon from oxidation and impr ove high temperature strength by the formation of carbides.
Carbon is added to refractories because it is not wetted by slags.The carbo n can form a film blocking the slag penetration thereby minimizing the dama ge it causes to the brick. However, the weakness of carbide is easily oxid ized in high temperature environment. In addition, as magnesia-carbon Brick is belong to one of resin-bond bricks, the resistant oxidation is low when they are operated in middle temperature.
The magnesia carbon bricks have high refractoriness as no low melting phase occurs between MgO and C. Because of the non-wetting of carbon, the magnes ia carbon bricks prevent the penetration of slag and molten steel. As The m agnesia carbon brick is made by high pressure, it shows excellent resistanc e to thermal shock and slag corrosion at elevated temperatures.
Graphite, the carbon source, has very low thermal expansion and very high t hermal conductivity. So magnesia carbon bricks have low thermal expansion a nd high thermal conductivity, which make magnesia carbon bricks have excell ent thermal shock resistance.
It is widely used in converters, BOF, EAF, ladles and refining furnaces as they possess superior slag penetration resistance and excellent thermal sho ck resistance at elevated temperature because of the non- wetting propertie s of carbon (graphite) with slag, high thermal conductivity, low thermal ex pansion and high toughness,etc.
Zhengzhou Sunrise Refractory Co., Ltd. is a refractory supplier from china, offering high quality Magnesia Carbon brick made from high quality dead-bu rned or fused magnesia and graphite.