You are here: Home » News » Product News » How are insulating fire bricks made?

How are insulating fire bricks made?

Views: 121     Author: Site Editor     Publish Time: 2020-04-10      Origin: Site

From the point of view of development and growth rate, China's refractory industry has farewell to the period of rapid development, and the development mode is transiting to the stage of industrial transformation and upgrading. In the past, purely pursuing the extensive growth of production capacity has no longer adapted to the development trend of the market. At present, the refractory industry is facing a serious imbalance between supply and demand, showing a situation of oversupply. Therefore, the emergence of refractory bricks has greatly alleviated this situation. So, I don't know what you know about firebricks? Here we briefly introduce insulating refractory bricks and related knowledge. Hope to help you better understand insulating refractory bricks.


The analysis points are as follows:

✉ What is insulated fire brick

✉ Type of insulated fire brick

✉ How is the insulating refractory brick made?

✉ Summary


What is insulated fire brick

Refractory brick is mainly designed for high temperature resistance, is a refractory material, often used in lining furnace, kiln, fire box and fireplace. Refractory bricks usually contain 30-40% aluminium oxide, and the main raw materials are usually used together with other materials. With the increase of alumina content, the kiln bricks with alumina content of 80% or higher can be obtained. Insulated refractory bricks are one of them. The fireproof brick has low thermal conductivity and low thermal storage. They can be used as hot surfaces or as backing insulation for compact bricks. The range of insulated fireproof bricks ranges from grade 23 to 32. With the development of related industries, it is now widely used in flue heat preservation, hot blast stove and kiln spare heat preservation materials.


Type of insulated fire brick

With the continuous development of related fields, the materials commonly used to make refractory bricks are corundum bricks, silicon carbide bricks, silicon nitride-bonded silicon carbide bricks, nitrides, silicides, sulfides, borides, carbides and other non-oxide refractories; calcium oxide, chromium oxide, alumina, magnesium oxide, beryllium oxide and other refractories. The commonly used thermal insulation fireproof bricks are high alumina bricks, corundum bricks, mullite bricks and andalusite bricks. Here we give a brief introduction.


(1) High alumina brick

High alumina hollow brick is made of high alumina and high alumina powder as the main raw materials, combined with other binders, and then fired at 1750 degrees. The utility model belongs to an energy-saving heat preservation material of ultra-high temperature material. The mechanical strength of the product is several times that of ordinary light products, and the volume density of the product is only half of that of corundum products. The product can greatly improve the thermal efficiency of the kiln, shorten the production cycle, reduce the weight of the kiln, thus achieving energy saving and consumption reduction. Now it is mainly used in refractories, industrial ceramics, electronic ceramics, petrochemical industry, metallurgy and other high temperature lining and ultra-high temperature kiln insulation materials and other industries. It has been widely used in high temperature and ultra high temperature kilns in petrochemical industry, carbon black industrial reaction furnace and metallurgical industry, and has achieved satisfactory energy-saving results.


(2) Corundum bricks

Corundum brick is a kind of refractory material. The content of alumina exceeds 90%. Corundum is the main crystalline phase. It has high compressive strength at room temperature. It also has good chemical stability and strong tolerance to acidic or alkaline slag, metal and glass liquids. Corundum bricks are divided into sintered corundum bricks and fused corundum bricks. It is mainly used in blast furnaces, hot blast stoves, refining furnaces, sliding water heaters, glass melting furnaces, Petrochemical furnaces and so on. It has become an important raw material for key components such as steel, electronics, petrochemical, fertilizer and so on. Non-ferrous metals and refractories industry.


(3) Mullite bricks

Mullite brick is a kind of lightweight mullite product, which is made of high quality and high purity refractory powder. According to the specific gravity of the product, organic composite filler is added, vacuum extrusion moulding and high temperature sintering are carried out. It has good high temperature stability and resistance to erosion and erosion of glass melt. It has little pollution to glass melt. It is suitable for the upper structure, material path, cover plate and forming parts of glass kiln. At the same time, it is also suitable for hot blast stoves and blast furnaces in iron and steel industry.


(4) Andalusite bricks

Andalusite bricks are made of calcined andalusite. Compared with refractory clay or light brick lining, the refractory brick made of andalusite can save 30-50% energy. In addition to reducing fuel consumption and improving stability, the use of andalusite refractory bricks can also save more than 40% of the consumption of general refractories. Now it can be used in hot stove, hot air tower, reheating and other key components. It can also be used in various auxiliary pouring and operating equipment. It can also be used to manufacture kiln equipment, high temperature aluminosilicate insulators, sand mold fabrics.

How is the insulating refractory brick made?

The main production processes of insulated refractory bricks are: raw material selection, powder preparation (crushing, crushing, screening), ingredients, mixing, pipe forming, drying, sintering, inspection and packaging.

The main steps are as follows:

(1) Filling: Filling material into the die by vibration and compaction.


(2) Demoulding: After filling the mold, the mold is placed in a temperature environment of 10-20 degrees Celsius for 24 hours before demoulding.


(3) Station: Bricks supported by mattresses are placed in indoor rain-proof and moisture-proof environment for 14 to 16 days.


(4) Kiln structure: brick wall is used as brick blank as kiln wall, steel lining refractory fiber blanket as top cover, covering the days of 100-40 mm in diameter. If one end of kiln wall is 1000, it is equipped with a kitchen, and the other end is connected with the chimney outlet.


(5) Drying:

1. Open the heavenly eye, raise the temperature in the kiln to a certain temperature with a certain heating rate, close the heavenly eye and keep the temperature 80-110 hours.


2. Open the heavenly eye, raise the temperature in the kiln to a certain temperature with a certain heating rate, close the heavenly eye and keep the temperature between 80 and 110 hours.

3. Reduce the temperature in the kiln to below 100 degrees Celsius and complete the drying stage.


(6)Light burning.


(7) Natural cooling.



After listening to our introduction, do you think insulating refractory bricks are widely used? With the development of industry, more and more refractory bricks are produced by people. If you want to buy suitable insulated refractory bricks, please choose us, our company is committed to the production of refractory bricks and other refractories. If you have any questions, please ask us in time.