Alumina content in fireclay bricks approximate 28-45% are classified to Medium-duty Fireclay brick, High-duty Fireclay brick and Super-duty Fireclay brick. Alumina content in fireclay bricks between about 10-28% are classified to low alumina fireclay bricks.

Good thermal shock and spalling resistane,good resistance to abrasion and corrosion。

Good volume stability at high temperature, high mechanical strength.

The main applications for fireclay brick are listed below: furnace construction，Blast furnace./hot blast stove.

Steel foundries.

Furnace in the nonferrous metal industry.

Coke ovens and gas furnace

Glass industry.

Cement industry

Safety lining of ladle.

Backup linging of boiler.

Classification		Sk 30	Sk32	Sk34	K43
Properties		Medium-duty fireclay brick	High-duty fireclay brick	Super-duty fireclay brick	Super-duty fireclay brick
Physical properties	Pyrometric cone equivalent	29-30 Orton cone	31-32 Orton cone	33-34 Orton cone	33-34 Orton cone
	Refractoriess	1670℃	1715℃	1760℃	1760℃
	Bulk density	2140-2150kg/m³	2200-2250kg/m³	2235-2250kg/m³	2275-2285kg/m³
	Apparent porosity	19.0-20.0%	18.0-19.0%	17.0-18.0%	17.0-18.0%
	Cold crushing strength	220-250kg/cm²	220-320kg/cm²	300-350kg/cm²	350-400kg/cm²
	Modulus of rupture	55-70kg/cm²	55-70kg/cm²	60-80kg/cm²	80-90kg/cm²
	Reheat test, permanent linear chang After heating at 1400℃	0.0-0.06%	0.0-0.2%	-0.18%	-0.50%
Thermal expansion	At 800℃	0.55%	0.50%	0.50%	0.55%
	At 1000℃	0.60%	0.60%	0.60%	0.60%
	At 1200℃	0.70%	0.70%	0.70%	0.65%
	At 1400℃	0.71%	0.72%	0.75%	0.70%
Chemical composition: (approximate)	Silica(SiO2)	64.10%	57.80%	52.40%	49.00%
	Alumina(Al2O3)	31.80%	36.20%	44.10%	45.80%
	Iron Oxide(Fe2O3)	1.90%	1.40%	1.40%	1.30%
	Calcium Oxide(CaO)	0.40%	0.50%	0.40%	0.40%
	Alkalines (Na2O+K2O+Li2O)	0.50%	0.50%	0.50%	0.50%