Brick made from bauxite, andalusite, mullite, tabular alumina or other alumina-rich raw materials blended with clay, carrying from 45 up to about 99 percent Al2O3. Higher alumina raises refractoriness, hot strength and resistance to many slags, at a price. Common grades are known simply by their alumina level, such as 60 or 80 percent brick, and they line ladle safety linings, cement kiln transition zones, incinerators, glass regenerators and aluminum furnaces.
Switch the ladle safety lining to 70 percent high-alumina brick, the fireclay is glazing and slumping.
More alumina is not always better. In some alkali-rich or slag environments a 60 percent brick outlasts a 90.
Also heard as
- high-alumina
- hi-alumina
- 70 percent brick
- bauxite brick
Related terms
Fireclay
Alumina-silica clay refractory, the classic firebrick, graded from low duty to super duty.
Spinel
Magnesium aluminate mineral used in chrome-free basic bricks and slag-resistant ladle castables.
Refractoriness
Ability of a material to withstand high temperature without softening or melting.
Safety lining
Refractory layer behind the working lining that holds molten metal back if the working lining fails.