Corundum Mullite Bricks

Corundum mullite bricks are made of synthetic fused or sintered mullite, pressed by selected shaping processes and fired in high-temperature furnaces. Corundum mullite bricks offer high density, low porosity, good hot strength, and good slag resistance.

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Introduction of Corundum Mullite Bricks

Corundum mullite brick is a high-quality furnace refractory brick that Xinhongji Refractory can provide with customized sizes. Corundum, synthetic mullite, and chromium oxide, which are pure alumina and mullite materials, are the main raw materials. Proper metal fines are added, and the mixture is processed by molding under high pressure and sintering at high temperatures (1650℃~1750℃).

Mullite Bricks are made of synthetic fused mullite or sintered mullite, pressed by selected shaping processes and fired in high-temperature furnaces. Mullite bricks offer high density, low porosity, good hot strength, and good slag resistance.

Corundum mullite bricks are one high alumina refractory product composed of corundum and mullite main crystal phases. Corundum mullite brick is a refractory product made of high-purity or purer raw materials. Low melting point oxide impurities reduce its high-temperature performance. Pure mullite raw materials are synthesized from industrial alumina powder and pure clay, bauxite, or silica. The product prepared by using mullite granules as aggregate has good thermal shock resistance, and the corundum sand as the aggregate product has good corrosion resistance.

Corundum mullite bricks have good high-temperature strength, high-temperature creep resistance, thermal shock resistance, and erosion 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.

A typical corundum-mullite brick has the following physical and chemical properties: Al₂O₃>85%, Fe₂O₃≤0.45%, an apparent porosity of about 19%, room temperature compressive strength greater than 55MPa, load softening temperature greater than 1700℃, heating line change (1600℃, 3h) of -0.1%, and thermal shock resistance (1100℃ water cooling) of more than 30 times.

Producing Procedure of Corundum Mullite Bricks

The raw materials of the corundum-mullite composite brick are composed of a corundum-mullite homogenized material, white corundum, andalusite, a-Al2O3 powder, and binding clay, as well as paper pulp liquid waste. The preparation method comprises the steps of firstly, preparing raw materials with various particle sizes according to the ratio; then, using raw materials with particle sizes of 1-3mm and particle sizes smaller than 1mm as aggregate to perform dry mixing, adding a paper pulp liquid waste mixture, finally adding the residual raw materials, and milling to obtain a pug; sequentially performing material trapping, press forming and drying on the obtained pug, and finally roasting to obtain a product. The corundum-mullite composite brick produced has very low porosity, high compression strength, and excellent thermal shock and corrosion resistance, can completely satisfy the harsh application environment of the cortex furnace, and can prolong the service life.

Features of Corundum Mullite Bricks

1. High-temperature resistance.

2. High strength, high compression resistance.

3. Excellent thermal shock resistance.

4. High bulk density, and good thermal conductivity.

5. Good wear resistance and acid-alkali corrosion resistance.

Advantages of Corundum Mullite Bricks

1. Fine thermal conductivity.

2. Good abrasion-resistant ability.

3. High-temperature endurance can make direct contact with flame.

4. High compressive strength, and good cold-crushing resistance ability.

5. Good chemical stability which can endure corrosive gas attack.

Corundum Mullite Bricks Application

1. Corundum mullite bricks suit large and medium-sized blast furnace bottoms.

2. Corundum mullite bricks are suitable for hearth ceramic masonry and wind, iron, and slag joint masonry.

3. Corundum mullite bricks are suitable for glass furnace superstructure bricks, material bricks, cover plates, and molded parts.

4. Corundum mullite bricks are suitable for medium-temperature carbon black reactor lining and other thermal equipment linings.

Chemical & Physical Index

Item		Mullite Bricks	Mullite Corundum Brick	Corundum Mullite Brick	Corundum Mullite Brick	Corundum Brick
Index	Unit	Mullite Bricks	Mullite Corundum Brick	Corundum Mullite Brick	Corundum Mullite Brick	Corundum Brick
Chemical Composition	Al₂O₃%	≥75	≥80	≥85	≥88	≥92
	SiO₂%	≤23	≤18	≤12	≤8	≤3.1
	Fe₂O₃%	≤1.0	≤0.5	≤0.4	≤0.3	≤0.1
Apparent Porosity	%	≤21	≤20	≤19	≤18	≤18
Bulk Density	g/cm³	≥2.65	≥2.70	≥2.75	≥2.85	≥3.00
Compressive Strength	Mpa	≥80	≥80	≥90	≥100	≥100
Refractoriness Under Load (RUL)	℃, 0.2Mpa, 0.6%)	≥1600	≥1650	≥1700	≥1700	≥1750
Application		Primarily used for the key parts of the industrial furnace of steel, electronics, petrochemicals, fertilizers, non-ferrous metals, refractory material, etc