Wear Resistant Aluminum Oxide Fire Proof Firebricks High Alumina Refractory Bricks

High Alumina Refractory Brick

Introduction:

High alumina refractory bricks are made from bauxite or kaolinitic clays. The definition high-alumina refractory bricks contain between 48 and 89 percent alumina. They are much harder and tougher than same grade of fireclay refractories at high temperatures and in basic environments. In addition, high alumina refractory bricks exhibit better volume stability and abrasion resistance. High alumina bricks are used in blast furnaces, blast-furnace stoves, and liquid-steel ladles etc.

 
The high alumina bricks are basically divided into three grades as per the amount Al₂O₃ they contain. These are

Grade I which includes Al₂O₃ for in the range of 75~81%

Grade II which includes Al₂O₃ for in the range of 60~75%

Grade III which includes Al₂O₃ for in the range of 48~60%

Top Grade which includes Al₂O₃ for in the range of 82~89%

Properties of High Alumina Bricks

The high alumina bricks are basically perfect and advanced refractory materials having a very high refractoriness up to 1750~1790, which is much higher than that of fire clay bricks and semi-silica bricks obviously.

The high alumina bricks are very durable in nature and are also well designed to be used in high-temperature area such as blast furnaces.

The high alumina bricks are usually constructed with higher refractoriness and low impurities.

These bricks include more Al₂O₃ content than that of other ones in the same category and hence can also be referred to neutral refractory material having resistance to acid and basic slag erosion.

Along with Al₂O₃ these bricks also comprise of SiO₂ content which enhance the resistance to acid slag erosion much more..

Characteristic as follows:
a, refractoriness; high alumina bricks refractoriness are higher than clay and semi-silica brick refractoriness up to 1750 ~ 1790℃, belonging to high-grade refractory.
b, load softening temperature; high aluminum products because of high Al₂O₃, less impurities, less fusible vitreous formed, so load softening temperature is higher than the clay brick, but not formed mullite crystalline , so load softening temperature silica brick is still not high.
c, slag resistance; Al₂O₃ in alumina bricks are more close to neutral refractories, resistant to erosion of acid and alkaline slag slag, because it contains SiO₂, so resistance to alkaline slag ratio of acid slag ability weaker.

Application of High Alumina Refractory Bricks

The high alumina bricks are mainly used in masonry in blast furnace, hot blast furnace, electric furnace roof, blast furnace, reflecting furnace, lining of rotary kiln. In addition, high alumina brick are widely used in open hearth furnace lattice brick, plug used in casting system, nozzle brick, etc. But the price of high alumina brick is higher than the clay brick, so we do not need high alumina brick when the clay brick can satisfy the demand.