Insulation Bricks

Insulating Fire Bricks are a special type of brick that can handle high temperatures and act as insulation. Insulating firebrick is used to line fireplaces, fireboxes, furnaces and kilns. It is sometimes referred to as “refractory brick” and is designed to withstand temperatures of up to 3,200⁰F while actually conducting very little of that heat in order to provide a greater level of energy efficiency.


Insulating firebrick is a refractory brick or block, of a ceramic material that is commonly used in a variety of different applications including fireboxes, all types of furnaces, melters and industrial kilns.


  • High Insulating Value –The light weight and high insulating value of BNZ IFB make possible thinner furnace walls, improved efficiency and lower operating costs.
  • Strength –The high compressive strength of IFB allows for self-supporting structures at elevated temperatures. IFB are compatible with dense fire brick, and add strength to the whole construction.
  • Low Heat Storage – Lower heat storage versus dense brick means reduced fuel costs and faster heat-ups in cyclically operated heating equipment.
  • High Purity – BNZ IFB are low in impurities such as iron, which can adversely affect refractory performance in many applications. They are used in many furnaces with controlled atmospheres.
  • Accurate Dimensions – Because BNZ Insulating Fire Brick are machined to precise dimensions, courses can be laid quickly and easily, and the result is a stronger, tighter refractory lining resulting in less heat loss through the joints.


Sl. No.Properties CFIHFIHFK-40Mullite Insulation
 Unit ValuesValuesValuesValues
Chemical Properties
1Al203%30(Min)30(Min)40-42 (Min.)60.0 (Min.)
2Fe203%2.5(Max)2.5(Max)2.0 (Max.)1.0 (Max.)
Physical Properties
3Bulk Density gm/CC0.80.91.0-1.21.0 (Max.)
4A.P%65(Min)60(Min)55 (Min)55 (Min)
5C.C.Sgm/Cm215(Max)20(Max)40 (min)25 (min)
6Thermal Conductivity at 600 °C W/mk0.350.40.45 (Max)0.40 (Max)
7Refractoriness orton 3030
8Service Temperature  0C125013001400 (Max.)1550 (Max.)