RS Sintered Mullite Bricks

Mullite Bricks

The high-temperature creep property is better.
High-temperature performance.
Corrosion resistance to acidic slag.
Corrosion resistance to low-alkaline.

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Mullite brick is a refractory product with mullite as the main crystal phase, made of artificial mullite as raw material. When the Al2O3 content of the product is lower than the theoretical composition of mullite, it also contains a small amount of cristobalite. When the Al2O3 content is higher than the theoretical composition of mullite, it contains a small amount of corundum. The high-temperature creep property of mullite brick is better than that of high-alumina brick produced from natural bauxite raw materials. Its high-temperature performance is comparable to that of siliceous and magnesia products, and its corrosion resistance to acidic and low-alkaline slag is better than that of magnesia products. There are two main types of mullite bricks: sintered mullite bricks and fused-cast mullite bricks.

Application of Mullite Bricks

Mullite bricks are mainly used for lining various parts of thermal kilns in industrial sectors such as steel, chemical, glass, and ceramics.

Sintered Mullite Bricks

The production process of sintered mullite bricks is similar to that of high-alumina bricks. Synthetic mullite is used as granular material, and fine powder is synthetic mullite, or white corundum, quartz powder and pure clay are used to prepare a mixed fine powder equivalent to the composition of mullite. The granular material and fine powder are mixed in proportion. The commonly used ratio is: 45%~55% granular material, fine powder (<0.088mm=55%~45%). After mixing evenly, high-pressure molding is performed. The firing temperature is 1550~1600℃. When fused mullite clinker is used as a granular material, its firing temperature should be greater than 1700℃. The physical and chemical performance indicators of sintered mullite bricks are shown in the table below.

Physical and Chemical Indicators of Sintered Mullite Bricks
Items	Hot Blast Stove Bricks	Plug Brick A	Plug Brick B	Plug Brick C
Al2O3 %	80.04	68.34	67.7	69.24
SiO2 %	18.20	–	–	–
Fe2O3 %	0.76	0.84	0.54	0.70
Apparent Porosity %	15.6 ~ 16.5	16.7	17.1	17.5
Compressive Strength at Normal Temperature MPa, ≥	197 ~ 267	77	65.7	83
Load Softening Start Temperature ℃	＞1700	1600	1650	1650
High-Temperature Creep Rate (1550℃, 50h) %	0.08	–	–	–
Bulk Density g/cm3	2.77 ~ 2.79	2.53	2.50	2.50

Fused-Cast Mullite Bricks

Fused-Cast Mullite Bricks are mainly made of high-alumina bauxite or industrial alumina, clay, or silica, which are melted in an electric arc furnace, cast, and annealed. The main mineral component of Fused-Cast Mullite Bricks is mullite. The following table shows the physical and chemical indicators of Fused-Cast Mullite Bricks.

Physical and Chemical Indicators of Fused-Cast Mullite Bricks
Al2O3 %	70.1 ~ 75.47
SiO2 %	19.32 ~ 21.6
Fe2O3 %	0.92 ~ 1.90
MgO	0.23 ~ 0.70
CaO	0.16 ~ 1.50
TiO2	3.1
Bulk Density g/cm3	2.90 ~ 3.30
Apparent Porosity %	＜10
Compressive Strength at Normal Temperature MPa, ≥	250 ~ 500
Refractoriness ℃	1730 ~ 1800
Load Softening Start Temperature ℃	1700
Thermal Expansion Rate (20 ~ 1000℃) %	0.60 ~0.65

Rongsheng Refractory Brick Manufacturer

Rongsheng is a powerful manufacturer of refractory bricks. Rongsheng’s mullite brick products, sintered mullite bricks, and fused-cast mullite bricks are of guaranteed quality. Factory direct sales, reasonable prices, and fast delivery! Whether you are planning to repair a furnace or build a new kiln, if you need to buy cheap refractory bricks, please choose Rongsheng. Rongsheng can provide high-alumina bricks, mullite bricks, corundum bricks, and other refractory bricks in standard and customized sizes according to the actual needs of your project. Contact Rongsheng for free samples, solutions, and quotes.