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Insulating Fire Brick · Grades JM-23 to JM-32

Lightweight Mullite Brick

Up to 1760°C Low Conductivity High Purity Easy Cutting

High-purity mullite insulating fire brick for industrial furnace hot face and backup lining — combining low thermal conductivity and low heat storage with high strength and excellent thermal shock resistance.

Classification1260°C – 1760°C
Bulk Density800 – 1100 kg/m³
GradesJM-23, JM-26, JM-28, JM-30, JM-32
Standard Size230 × 114 × 65 mm
PackingPallets or carton boxes

Request a Quote Technical Data

Lightweight Mullite Insulating Fire Brick

Product Overview

Lightweight Mullite Brick is manufactured from high-purity refractory materials, precisely proportioned with organic composite fillers, vacuum extruded, and high-temperature sintered to form a premium insulating fire brick.

It offers low thermal conductivity, low heat storage, high purity and low impurity content, direct flame contact capability, high strength, excellent thermal shock resistance, and precise dimensions — and can be cut to any required shape.

Product Features

Low Thermal Conductivity

Excellent insulation, with conductivity as low as 0.21 W/m·K at 350°C.

Low Heat Storage

Minimal heat absorption for faster heating cycles and energy savings.

High Purity

Low impurity content, with Al₂O₃ up to 79% for superior performance.

Direct Flame Contact

Withstands direct flame exposure without degradation.

High Strength

Cold crushing strength up to 4.6 MPa for structural integrity.

Easy Machining

Precise dimensions, with the ability to cut to any required shape.

Product Grades

JM-23

1260°C
800 kg/m³

JM-26

1430°C
800 kg/m³

JM-28

1540°C
900 kg/m³

JM-30

1650°C
1000 kg/m³

JM-32

1760°C
1100 kg/m³

Technical Specifications

Property	JM-23	JM-26	JM-28	JM-30	JM-32
Classification Temperature (°C)	1260	1430	1540	1650	1760
Bulk Density (kg/m³)	800	800	900	1000	1100
Reheat Linear Change (%)	1280°C×3h ≤0.6	1380°C×3h ≤0.6	1500°C×3h ≤0.8	1550°C×3h ≤0.8	1570°C×3h ≤0.8
Cold Crushing Strength (MPa)	1.8	2.4	3.0	3.6	4.6
Thermal Expansion @1000°C (%)	0.5	0.5	0.55	0.58	0.60
Thermal Conductivity @350°C (W/m·K)	0.21	0.25	0.28	0.33	0.40
Al₂O₃ Content (%)	40	50	62	70	79
Fe₂O₃ Content (%)	≤1.0	≤1.0	≤0.8	≤0.6	≤0.5

Product Dimensions

Standard Size

230 × 114 × 65 mm

Custom Sizes

Available upon request

Packing

Pallets or carton boxes