Alumina-silicon Refractory Bricks

Silicon Mullite Andalusite Brick

Name: Silicon Mullite Andalusite Brick
Brand: XZK

Silicon mullite andalusite bricks, called guimo red brick in the Chinese industry after their colour, combine 75% Al2O3 with a silicon carbide and silica fraction of 30% or more, plus an andalusite addition. The three phases are chosen to work together: mullite for creep resistance, SiC for...

Al₂O₃:≥75%

SiC+SiO₂:≥30%

Bulk Density:≥2.65g/cm³

Cold Crushing Strength:≥95MPa

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Silicon Mullite Andalusite Brick Overview

Silicon mullite andalusite bricks, called guimo red brick in the Chinese industry after their colour, combine 75% Al₂O₃ with a silicon carbide and silica fraction of 30% or more, plus an andalusite addition. The three phases are chosen to work together: mullite for creep resistance, SiC for thermal shock and abrasion resistance, and andalusite for controlled mullitisation and spalling resistance.

XZK Group supplies the material in two grades, XZK-SMA75 and the special XZK-SSM75, and specifies it for the most severely cycled and scoured positions of the furnace.

Three Phases Working Together

Where the earlier guimo brick relies on a high alumina matrix plus SiC, this material also adds andalusite. Andalusite mullitises in the kiln with a controlled expansion, so the fired brick combines a mullite matrix with the microcracked, crack-toughened structure that gives andalusite its thermal shock resistance. The result is a brick that is stiff enough to resist creep and tough enough to survive repeated cycling.

The silicon carbide and silica fraction, held at 30% or above, does the rest. It raises thermal conductivity and evens out the temperature gradient, provides a hard phase against abrasion, and improves alkali resistance. The special grade raises the SiC and SiO₂ fraction to 35% and cold crushing strength to 100 MPa for the hardest duty.

With 75% Al₂O₃, a refractoriness under load of 1650°C and thermal shock resistance of 15 to 20 water-cooling cycles at 1100°C, the material sits at the top of the alumina-silica silicon carbide family. It is pressed and fired to a bulk density of 2.65–2.68 g/cm³.

Key Properties

75% Al₂O₃ with an SiC and SiO₂ fraction of 30–35%.
Refractoriness under load of at least 1650°C at 0.2 MPa, among the highest in the family.
High cold crushing strength of 95–100 MPa, giving real structural capability.
Thermal shock resistance of 15–20 water-cooling cycles at 1100°C.
Improved alkali and abrasion resistance from the silicon carbide fraction.
Bulk density of 2.65–2.68 g/cm³ for a dense, load-bearing body.

Technical Specifications

Technical Properties	XZK-SMA75	XZK-SSM75 (Special)
Al₂O₃ (%)	≥ 75	≥ 75
SiC + SiO₂ (%)	≥ 30	≥ 35
Bulk Density (g/cm³)	≥ 2.65	≥ 2.68
Cold Crushing Strength (MPa)	≥ 95	≥ 100
Refractoriness Under Load (0.2MPa, ℃)	≥ 1650	≥ 1650
Thermal Shock Resistance (1100℃ water-cooled, cycles)	≥ 15	≥ 20

Test methods follow GB/T and ISO practice; ASTM equivalents and full certificates of analysis are issued with every shipment.

Available Grades and How to Choose

The two grades differ in the size of the silicon carbide and silica fraction and in the strength that follows, and both share the 75% alumina base and the 1650°C refractoriness under load.

XZK-SMA75, with an SiC and SiO₂ fraction of at least 30% and cold crushing strength of 95 MPa, is the standard grade for combustion and regenerator hot-zone work. XZK-SSM75 raises the fraction to 35% and cold crushing strength to 100 MPa, and lifts thermal shock resistance from 15 to 20 cycles; it is specified for the most severely cycled and scoured positions, where the extra toughness justifies the additional cost.

As with all silicon carbide bearing refractories, the material should not be used where the atmosphere and temperature would promote rapid oxidation of the carbide, and XZK confirms suitability against the furnace conditions before recommending a grade.

Industry Applications

Mainly used in non-firing high-temperature areas of large dry-process cement rotary kilns, such as transition zones, kiln hoods, grate coolers, tertiary air ducts, etc., serving both load - bearing and thermal-insulation functions.

Where Silicon Mullite Andalusite Bricks Are Used in a Glass Furnace

The material is chosen for positions that combine high temperature, thermal cycling and mechanical wear, in particular:

Burner block and combustion zone. High strength and thermal shock resistance let the brick take the flame and the reversal cycle at the hottest point of the furnace.
Port crown and port neck, where the arch cycles on every reversal and flame scour is at its most severe.
Regenerator hot-zone courses, where the combination of alkali vapour, dust and temperature change destroys weaker materials.
Doghouse and charging-end structures, where abrasive batch dust needs a hard surface and the charging cycle needs spalling resistance.
Throat and waist wall working faces, where melt velocity, wear and thermal cycling coincide.

Manufacturing and Quality Control

Manufacturing is controlled from raw material through to finished brick. Four automatic batching lines feed 20 CNC presses ranging from 630 to 2000 tonnes, so density is set by press force rather than operator judgement, and firing runs through four 108-metre fully automatic tunnel kilns and five ultra-high-temperature shuttle kilns for a uniform soak.

Every batch is tested for bulk density, apparent porosity, cold crushing strength and refractoriness under load, and ships with a certificate of analysis. XZK Group holds ISO 9001, ISO 14001, ISO 45001 and ISO 50001 certification and operates the Henan Provincial Engineering Technology Research Center for Sintered Refractories for Glass Furnaces.

Related Refractory Products

Silicon mullite andalusite bricks are supplied with high alumina silicon carbide bricks, andalusite bricks, sillimanite bricks and mullite bricks. See the alumina-silicon bricks range or browse all refractory products.

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About XZK Group

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Product Portfolio

Specializing in premium zircon, corundum, sintered AZS, and monolithics. With a $70M+ annual output, we deliver durable linings for global high-temp industries.

Capacity

✔ 4 automated microcomputer batching systems.

✔ 4 ultra-high-temp tunnel kilns & 5 shuttle kilns.

✔ 20+ CNC hydraulic presses (630-1500T).

✔ Digitalized workshops with 100,000T annual capacity.