Product Details

Description:

Mullite Refractory Bricks (also called mullite bricks) are made of synthetic fused mullite or sintered mullite, pressed by selected shaping processes, and fired in high temperature furnaces. Mullite refractory bricks offer high density, low porosity, good hot strength, and good slag resistance. Mullite bricks are preferred for high temperature, high load applications, such as at the hot end of regenerative chambers of glass melters, the superstructure of the furnace, and the arch of glass fiber melters, due to their excellent thermal properties, excellent strength at high temperature, great resistance to thermal shock, etc.

The mullite brick comprises the following chemical components in percentage by weight: 35 to 72 percent of Al₂O₃, 27 to 64 percent of SiO₂, and 1 to 1.2 percent of Fe₂O₃. Mullite bricks are high-alumina refractories with mullite (3 Al₂O₃·2SiO₂) as the main crystal phase. Generally, the alumina content is between 70% and 80%. Mullite Refractory bricks have high refractoriness, which can reach above 1790℃. The starting temperature of load softening is 1600～1700℃. It has the good thermal shock resistance with cold crushing strength of 70～260MPa. There are two types of mullite refractories: sintered mullite bricks and fused mullite bricks. If the Al₂O₃ content in refractory brick is more than 80%, we call it as corundum mullite brick. If there is ZrO₂ in the brick, we call it as Zircon Mullite Brick.

Mullite refractory bricks are widely used in glass furnaces, hot blast stove and etc.

Features of Mullite Refractory Bricks

Low levels of iron and other impurities
High mechanical intensity
High refractoriness, can contact with the flame directly, suitable for various atmosphere
High porosity, low volume density, low thermal conductivity
Good heat insulating performance and energy-efficient
Low creep rare at high temperature,good thermal shock stability
Chemical corrosion resistance
Long service life

Specifications.

Item / Types		JM-23	JM-26	JM-28	JM-30	JM-32	XIJJM-35
Chemical Composition (%)	Al₂O₃	40	55	65	70	75	80
	SiO₂	50	42	33	26	22	17
	Fe₂O₃	1	0.8	0.7	0.7	0.5	0.2
	TiO₂	1.2	1.3	0.9	0.5	0.3	0.3
	CaO+ MgO	0.7	0.6	0.2	0.3	0.2	0.2
	K₂O+ Na₂O	1.3	1.1	0.8	0.2	0.1	0.1
Classification temperature (ºC)		1300	1420	1530	1550	1650	1700
Bulk Density (g/cm3)		0.6	0.8	0.9	1	1.1	1.1
Cold Crushing Strength (MPa)		1.2	1.8	2.5	3.3	3.5	3.5
Modulus of rupture (MPa)		1	1.7	2.3	3.1	3.2	3.2
Permanent linear change (CT x24h)%		0.6	0.6	0.8	0.9	1.01	1.01
Thermal Expansion(%) @ 1000ºC		0.5	0.52	0.52	0.53	0.6	0.7
Thermal conductivity (W/m.k)	350ºC	0.18	0.27	0.32	0.38	0.45	0.49
	400ºC	0.2	0.29	0.34	0.4	0.45	0.5
	600ºC	0.24	0.32	0.36	0.42	0.47	0.51