Silica Insulation Brick – High Temperature Lightweight Thermal Insulation Refractory-Henan Hongtai Kiln Refractory CO.,LTD.

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Silica Insulation Brick – High Temperature Lightweight Thermal Insulation Refractory

Product Overview

Silica insulation brick, also known as lightweight silica insulating refractory brick, is a porous lightweight heat preservation material dominated by high-purity silica raw materials. Its silicon dioxide (SiO₂) content is controlled above 91%, with main mineral phases of tridymite, cristobalite and a small amount of residual quartz. Manufacturers mainly adopt two mature production processes: burnout method and foaming method. Organic combustible materials such as sawdust, anthracite and coke powder are mixed into raw materials, which burn out during high-temperature sintering to form uniform internal microporous structures, balancing lightweight performance and high-temperature mechanical stability. The bulk density of standard grades ranges from 1.00 g/cm³ to 1.20 g/cm³, far lower than dense solid silica bricks, making it the preferred back lining insulation material for various high-temperature industrial kilns without direct contact with molten slag or alkaline media.

Core Product Advantages

Outstanding high-temperature bearing performance

The load softening temperature of silica insulation brick reaches 1400℃–1550℃, comparable to dense silica bricks, far exceeding clay insulation bricks and high alumina insulation bricks of the same density. It maintains stable volume and structural strength under long-term high-temperature working conditions, no soft deformation or collapse occurs inside kilns, effectively supporting the main working layer refractory bricks. The permanent linear shrinkage after repeated high-temperature heating is controlled within 0 to +0.5%, with tiny residual expansion, stable kiln lining structure and low risk of cracking and air leakage.
Ultra-low thermal conductivity for obvious energy saving effect

Thanks to its evenly distributed closed pores, the thermal conductivity stays between 0.35–0.70 W/(m·K) under different temperature sections. Compared with traditional heavy refractory lining, it can reduce surface heat loss of kilns by nearly 30%, cut down fuel and power consumption for heating equipment, lower running cost of industrial production lines, and realize energy conservation and emission reduction for high-temperature furnaces. The surface temperature of kiln outer wall can be controlled below 80℃ after laying silica insulation bricks, improving workshop operation environment and reducing heat radiation hazard to workers.
Light weight with reliable mechanical strength

Low bulk density greatly reduces the overall load of kiln steel frame structure, lowering requirements for foundation and bracket design, saving construction steel cost and shortening on-site installation cycle. Even with lightweight feature, its cold crushing strength reaches 2.0–5.0 MPa, higher than ordinary lightweight clay bricks. The finished bricks have neat edges and stable size tolerance, convenient for cutting, splicing and layered masonry during construction, and will not break easily during transportation and stacking.
Excellent acid corrosion resistance and thermal stability

As an acidic refractory product, it resists erosion from acid flue gas, sulfur-containing waste gas and acidic slag generated in glass, metallurgy and ceramic production lines, effectively delaying lining aging. Its porous structure can buffer thermal stress generated by temperature fluctuation, showing better thermal shock resistance than dense silica bricks. It can operate continuously at 1500–1550℃ for a long time, suitable for intermittent heating kilns with frequent temperature rise and cooling cycles.

Main Application Fields

Silica insulation brick is specially used for thermal insulation layers of high-temperature kilns that do not directly contact alkaline melt, widely covered in multiple heavy industries:

Glass manufacturing industry: Insulation back lining for glass melting furnace crown, breast wall and regenerator vault. It protects main silica working bricks, stabilize furnace internal temperature field and reduce glass raw material melting energy consumption.
Metallurgy & coking industry: Wall and dome insulation of hot blast stoves, heat preservation layer of coke oven door, lining back insulation of carbonization furnaces and steel rolling heating furnaces. It maintains stable hot air temperature and improves blast furnace smelting efficiency.
Ceramic & building materials industry: Tunnel kiln, shuttle kiln and roller kiln vault and wall insulation for ceramic tile, sanitary ware and refractory firing lines, shortening heating up time and improving product firing uniformity.
Chemical high-temperature equipment: Insulation lining of high-temperature reaction furnaces, calcining furnaces and waste incinerators with acid flue gas emission.

Standard Technical Grades & Customization Service

We supply multiple mature standard grades including LWS-1.0, LWS-1.1, LWS-1.15 and LWS-1.2 to match different kiln temperature and load requirements. Complete technical indicators such as SiO₂ purity, bulk density, compressive strength, thermal conductivity and refractoriness under load can be provided for customer reference. Besides standard straight bricks, we support customized special-shaped silica insulation bricks including arch bricks, wedge bricks, split bricks and cut pieces according to customers’ kiln drawing dimensions. All finished products adopt fumigated export wooden pallet packaging to avoid breakage during long-distance sea and land transportation, with strict inspection before shipment to guarantee stable batch quality.

Installation & Usage Notes

Silica insulation brick is only applicable to the insulation backing layer, cannot be used as direct working layer contacting molten slag, alkaline liquid or strong alkaline gas. During masonry, matched silica insulation mortar is recommended to ensure tight joint sealing and prevent hot air penetration. The material has large crystal volume change below 600℃, so the kiln heating-up curve must be controlled slowly in low-temperature stage to avoid brick cracking caused by rapid temperature change. It shall be stored in dry and ventilated warehouse, covered with waterproof cloth to prevent moisture absorption, and damp bricks are forbidden to be directly put into high-temperature kilns for use.

Factory Strength & Global Supply

Our factory specializes in refractory production for more than ten years, with full automatic batching, high-temperature shuttle kiln sintering and finished product testing production lines. All silica insulation bricks strictly follow international refractory testing standards, and have been exported to Southeast Asia, Middle East, Europe and other regions, serving glass, metallurgy and ceramic manufacturers of all scales. We provide one-stop supporting services including product parameter matching, kiln lining masonry scheme consultation, on-site technical guidance and after-sales quality tracking, to deliver cost-effective high-temperature thermal insulation solutions for global industrial customers.

Silica Insulation Brick – High Temperature Lightweight Thermal Insulation Refractory

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