Products — Glass industry

Refractories for float, container and specialty glass furnaces

A glass tank punishes its lining in three different ways at once — molten glass corrosion at the metal line, alkali vapour in the superstructure and sulphate attack in the regenerator. Each zone gets its own material.

9: Glass product families
1750 °C: Maximum service temperature
100k t: Annual production capacity
1979: Making refractories since

Product catalogue

Grades & technical data

Silica & clay

Siliceous firebrick

High-purity silica brick with low residual quartz for glass-furnace crowns, breast walls and port necks. Excellent load-bearing capacity close to its melting point and very low creep, so crowns hold geometry over a full campaign.

Typical zones: Melter crown · breast wall · port crown · regenerator top chamber

Model	RTSA-GS95	RTSA-GS96
SiO2 (%) ≥	94.5	96.0
Al2O3 (%) ≤	1.0	0.7
Fe2O3 (%) ≤	1.2	0.8
Bulk density (g/cm³) ≤	1.85	1.82
Apparent porosity (%) ≤	22	21
Compressive strength (MPa) ≥	35	40
Refractoriness under load T0.6 (°C) ≥	1650	1670
True density (g/cm³) ≤	2.34	2.33

Silica & clay

Clay brick

Fireclay brick for the cooler structural parts of the furnace and regenerator — flues, checker support, chimney and backup insulation layers. Stable volume, good thermal-shock resistance and economical for large volumes.

Typical zones: Regenerator lower chamber · flues · checker support · backup lining

Model	RTSA-N1	RTSA-N2a	RTSA-N2b
Al2O3 (%) ≥	42	40	35
Apparent porosity (%) ≤	22	24	26
Bulk density (g/cm³) ≥	2.15	2.10	2.05
Compressive strength (MPa) ≥	45	35	30
Refractoriness under load T0.6 (°C) ≥	1400	1350	1300
Refractoriness (°C) ≥	1730	1710	1690

Silica & clay

High alumina brick

Bauxite-based high alumina brick used where the load and temperature exceed clay-brick limits: regenerator middle chamber, working-end superstructure and feeder channels. Higher hot strength and better alkali-vapour resistance.

Typical zones: Regenerator middle chamber · working end · feeder / forehearth structure

Model	RTSA-LZ55	RTSA-LZ65	RTSA-LZ75
Al2O3 (%) ≥	55	65	75
Fe2O3 (%) ≤	2.0	2.0	1.8
Apparent porosity (%) ≤	22	21	20
Bulk density (g/cm³) ≥	2.35	2.45	2.60
Compressive strength (MPa) ≥	50	55	65
Refractoriness under load T0.6 (°C) ≥	1470	1500	1520
Thermal shock resistance 1100 °C water (cycles) ≥	8	8	10

Fused cast & corundum

Fused zirconium high purity corundum brick

Fused-cast AZS-type block combining zirconia and high-purity corundum. The zirconia phase resists molten-glass corrosion at the metal line while the corundum matrix keeps glass defects (stones and cords) to a minimum.

Typical zones: Melter side wall / metal line · throat · bottom paving · dog house

Model	AZS-33	AZS-36	AZS-41
ZrO2 (%) ≥	32	35	40
Al2O3 (%)	50–52	48–50	44–46
SiO2 (%)	15–16	13–14	12–13
Na2O (%) ≤	1.3	1.3	1.3
Bulk density (g/cm³) ≥	3.75	3.90	4.05
Apparent porosity of matrix (%) ≤	1.2	1.2	1.0
Glass-phase exudation temperature (°C) ≥	1400	1400	1400
Maximum service temperature (°C)	1650	1680	1700

Fused cast & corundum

Fused corundum brick

α/β fused-cast alumina block with virtually no glassy phase — the reference material for contact with high-quality float, borosilicate and display glass where stone and bubble defects cannot be tolerated.

Typical zones: Working end · throat cover · forehearth · stirrer chamber · superstructure over metal line

Model	α-Al2O3	α/β-Al2O3	β-Al2O3
Al2O3 (%) ≥	98.5	94.0	94.0
Na2O (%)	≤ 0.5	3.0–4.0	5.5–6.5
SiO2 (%) ≤	0.8	0.8	0.8
Bulk density (g/cm³) ≥	3.50	3.40	3.00
Apparent porosity (%) ≤	2.0	2.0	3.0
Maximum service temperature (°C)	1750	1700	1650

Fused cast & corundum

Zircon brick

Sintered zircon (ZrSiO4) brick with outstanding resistance to molten glass and alkali vapour and very low thermal expansion. Used for paving, sidewall backup and forehearth blocks in demanding glass compositions.

Typical zones: Bottom paving · sidewall backup · forehearth channel blocks

Model	RTSA-Z64	RTSA-Z66
ZrO2 (%) ≥	64	66
SiO2 (%)	31–33	30–32
Fe2O3 (%) ≤	0.5	0.3
Bulk density (g/cm³) ≥	3.70	3.80
Apparent porosity (%) ≤	18	16
Compressive strength (MPa) ≥	100	120
Refractoriness under load T0.6 (°C) ≥	1650	1680

Basic bricks

High purity magnesium brick

High-purity sintered magnesia brick for the regenerator checker top, where alkali sulphate and carry-over batch dust attack acidic materials. High refractoriness and excellent heat-storage behaviour.

Typical zones: Regenerator upper checker · target wall · crown of regenerator chamber

Model	MZ-95	MZ-97	MZ-98
MgO (%) ≥	95	97	98
SiO2 (%) ≤	2.2	1.5	0.8
CaO (%) ≤	1.8	1.6	1.2
Bulk density (g/cm³) ≥	2.95	3.00	3.02
Apparent porosity (%) ≤	18	17	16
Compressive strength (MPa) ≥	60	65	70
Refractoriness under load T0.6 (°C) ≥	1700	1700	1700

Basic bricks

Directly bonded magnesia brick

Direct-bonded magnesia brick fired at high temperature so periclase grains bond to each other rather than through a silicate phase — markedly better hot strength and resistance to alkali and sulphate corrosion in the regenerator.

Typical zones: Regenerator checker · chamber wall · port neck backup

Model	DMZ-95	DMZ-97
MgO (%) ≥	95	97
CaO/SiO2 ratio ≥	2.0	2.0
Bulk density (g/cm³) ≥	2.98	3.02
Apparent porosity (%) ≤	17	16
Compressive strength (MPa) ≥	65	75
Refractoriness under load T0.6 (°C) ≥	1700	1720
Modulus of rupture 1400 °C (MPa) ≥	6.0	8.0

$Thermal insulation materials and amorphous refractory materials$

Insulation & monolithics

Thermal insulation materials and amorphous refractory materials

Complete backup and monolithic package: lightweight insulating brick, calcium-silicate and ceramic-fibre board, plus castables, ramming mixes, mortars and coatings used to seal, patch and insulate the furnace shell — cutting heat loss and stabilising crown temperature.

Typical zones: Backup insulation · crown coating · burner blocks · patching and hot repair

Model	Insulating brick	Ceramic fibre board	Castable
Classification temperature (°C)	1350	1430	1600
Bulk density (g/cm³)	0.8–1.0	0.28–0.32	2.30–2.60
Thermal conductivity 350 °C (W/m·K) ≤	0.35	0.10	—
Compressive strength (MPa) ≥	3.0	—	60
Al2O3 (%) ≥	48	45	70
Permanent linear change (%)	±0.5	≤ 2.0	±0.4

Planning a furnace build or cold repair?

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