What are insulating fire bricks made of?

Insulating fire brick, also popularly known as soft brick or IFB, is a kind of refractory materials, designed for extreme conditions with high temperature ranging from 1000 Celsius degrees to 1800 Celsius degrees. The most special features about large insulating fire bricks are that they have light weights and they can be easily modified or cut with hand tools. These two physical properties are mainly caused by the structures of large insulating fire bricks. Therefore, people might wonder what their contents are and how they are made that lead to these excellent characteristics. The passage below will provide some explanations.

-        What are insulating fire bricks?

-        What are the contents of insulating fire bricks?

-        How are they made?

What are insulating fire bricks?

The large insulating fire brick is a type of industrial material with thermal resistance and refractoriness. In the meanwhile, it is soft in texture and light in weight. They can be easily cut with hand saws or any other hand tools, such as chisels or even drills. Insulating fire bricks vary in color but usually range from light brown to white. In the fire-resistant air is the best insulation, which is why the large insulating fire brick has excellent insulation performance. There are a number of tiny air spaces similar to the honeycomb effect within the inside of large insulating fire bricks.

What are the contents of insulating fire bricks?

Insulating fire bricks are made of high purity refractory clays and other ceramic materials according to international standards. Due to differences in their compositions, there are many types of large insulating fire bricks such as lightweight silica insulating fire bricks, lightweight alumina insulating fire bricks etc. But generally, they are made of silica and alumina. Insulating fire bricks are suitable for various temperatures up to 1700 Celsius degrees.

Moreover, they contain a carefully graded organic filler which is burned during manufacturing to provide a controlled porous structure. Its high porous rate gives large insulating fire bricks an excellent insulation property and also helps them have light weight.

How are they made?

The method of manufacturing large insulating fire bricks depends largely on the materials used.

In a large number of cases, we utilize refractory clay as material. Clay is burnt in the kiln until some parts of it become vitrified. The product may sometimes be glazed according to customers’ wish. Most of them are in standard sizes, but they can also appear in the "split" form which is half the standard thickness.

There are also other ways to produce insulating fire bricks, but the main point is to render raw materials porous inside. People may use natural or artificial light weight materials as ingredients to manufacture bricks. Sometimes they even directly cut natural porous raw rocks with light weight into blocks. If the raw materials employed are not porous, manufacturers will use chemical reactions, such as adding foaming agent to rubber (e.g. rosin soap) to obtain a porous structure after firing.