Why are zircon bricks used under AZS in glass tanks?

Zircon bricks are used as bottom paving beneath the AZS sidewalls because they resist glass penetration and "upward drilling" while remaining dimensionally stable. Their low thermal expansion allows tight joints, and they provide a stable, corrosion-resistant base layer that extends the life of the tank bottom.

What is the difference between zircon brick and AZS block?

Zircon brick is sintered from natural zircon (ZrSiO₄) and is used mainly for paving, throat and inserts. Fused cast AZS is melt-cast with added alumina and higher effective zirconia, giving even greater glass-corrosion resistance for sidewalls and the most aggressive zones. Zircon is more economical; AZS handles the highest-wear contact areas.

Where else are zircon refractories used?

Besides glass tank paving, throat and forehearth, zircon refractories are used as slide-gate plate inserts, in steel and investment casting, and in foundry nozzles and runners. Their dimensional stability under thermal cycling makes them valuable wherever a precise, erosion-resistant shape must be held.

Zircon Bricks (ZrSiO₄) | Glass & Foundry

PRODUCT OVERVIEW

Zircon bricks are made from sintered zircon (ZrSiO₄, ~62–66% ZrO₂), combining very low thermal expansion, high corrosion resistance to molten glass and excellent thermal shock resistance. They are widely used as bottom paving beneath AZS in glass tanks, in throat and spout areas, and as inserts in flow-control refractories where dimensional stability is essential.

KEY PROPERTIES

ZrO₂ Content

62 – 66%

Max Service Temp

Up to 1700°C

Bulk Density

3.3 – 3.7 g/cc

Thermal Expansion

Very low

Glass Corrosion

Excellent

Thermal Shock

Excellent

APPLICATIONS

Glass tank bottom paving below AZS

Glass furnace throat & spout

Slide gate plate inserts

Steel & investment casting

Foundry nozzle & runner

Glass forehearth blocks

TECHNICAL SPECIFICATIONS

Grade	ZrO₂	SiO₂	Porosity	CCS	Max Temp
ZS-65	62-66%	32-34%	14-20%	150 MPa	1700°C
Zircon-Mullite	40-50%	25-30%	16-20%	120 MPa	1650°C

* Test conditions: IS 1528 (India) / ASTM C-133 / EN 1402. Values are typical — exact data sheets available on request.

AVAILABLE GRADES

ZS-65 (sintered zircon)Zircon-MulliteFused-bonded Zircon

INSTALLATION NOTES

1
Joint with zircon-based mortar to maintain corrosion resistance at seams
2
Use as bottom paving beneath AZS sidewalls in glass tanks
3
Low thermal expansion allows tight joints — follow OEM heat-up curve
4
Excellent for areas demanding dimensional stability under thermal cycling

WHY BUY FROM SHANKER AGENCIES

Shanker Agencies supplies Calderys zircon bricks and zircon-mullite grades for glass and foundry customers, sized to drawing with technical guidance on paving layout.

PARTNER BRANDS

Calderys CUMI

FREQUENTLY ASKED QUESTIONS

Zircon bricks are made from sintered zircon (ZrSiO₄), containing roughly 62–66% ZrO₂ and 32–34% SiO₂. The zircon mineral gives very low thermal expansion, excellent thermal shock resistance and strong resistance to molten glass and slag corrosion, which is why zircon is used in glass tank paving and flow-control inserts.

QUICK INFORMATION

Max Temperature

1700°C

MORE IN SHAPED REFRACTORIES

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Volume-stable andalusite bricks that mullitise in service for stoves, reheating furnaces and kilns

Fused Cast AZS Blocks

Melt-cast alumina-zirconia-silica blocks for glass furnace contact zones with exceptional corrosion resistance

Alumina-Carbon Bricks

Graphite-bonded alumina-carbon bricks for steel ladle walls, slag zones and impact pads

READY TO ORDER OR NEED A SAMPLE?

Our engineers can recommend the exact grade for your application. Sample kits available for trials. No minimum order on standard grades.

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ZIRCON BRICKS