Features And Applications Of Silimanite Brick

Silimanite brick is a kind of refractory which is made by silimanite and other minerals. It features dense structure, high refractoriness, high strength at high temperature and good corrosion resistance. 

Silimanite brick has great high temperature performance and is easy to produce. Silimanite brick is generally produced by high temperature sintering method and slip casting method. 

 

It mainly consists of Al2O3 and SiO2. Its physical and chemical properties are better than high alumina brick. Its refractoriness is high from refractoriness 1770 to 1830 ℃. Its softening temperature under load is about 1500 ~ 1650 ℃. 

 

Sillimanite is formed from aluminum silicate and is a transparent to translucent mineral ranging from white to gray, brown and green. Silimanite can be converted to be mullite and free SiO2 above 1500℃. It is stable in all temperatures up to 1550ºC after which it gets converted to mullite. It is most widely used as a refractory raw material owing to its perfectly suited thermal properties. It has low coefficient of thermal expansion. Between 1545º to 1550ºC, as it changes over to mullite there is a fairly rapid permanent expansion. 

 

One outstanding feature of Silimanite brick is the minimum increase in porosity upon heating. Moreover, if heating is prolonged, it tends to decrease as a consequence of vitrification. Such compactness offers great advantage in all applications in which problems of corrosion and abrasion arise.

 

Silimanite brick is very resistant to glass slag and hence widely used as lining material in glass melting furnace. Iron corrodes it rapidly hence it is not suitable in iron smelting. It is also not highly resistant to molten metallic oxides and, therefore, rather unsuitable for metallurgical operations.

 

Sillimanite bricks are widely used in feeder channels, feeder covers, burners, melting bottom paving of glass furnaces and other applications.