The Advantage of Fire Clay Brick

Fire clay brick is made of clay(shale, coal gangue, etc.) as the main raw material by mud handling, molding, drying and firing. 

China has successively created the square and elongated brick in the the Spring and Autumn Period. In the Qin and Han Dynasty, the technology, production scale, quality and varieties of bricks had a significant development and improvement, which is known as brick of Qin dynasty, tile of Han dynasty. 

 

The dimension of common bricks is 240mm×115mm×53mm. according to the compressive strength (N/mm2), they can be divided into six strength classes: MU30, MU25, MU20, MU15, MU10 and MU7.5. 

 

Fire clay brick obtains raw material locally. It is cheap and durable. It has the advantages such as fire protection, thermal insulation, sound insulation, moisture absorption, etc.. Waste and scrap bricks can be used as the concrete aggregate. To improve the disadvantage of fire clay brick such as small size, large weight and high clay consumpion, lightweight, high strength, hollow and large block of fire clay brick is developed. 

 

Sand-lime brick is made of an appropriate proportion of lime and quartz sand, fine sand or sandstone. The raw materials are ground, mixed with water, molded by semi-dry pressing and autoclaved and cured. 

 

Fly ash brick is made of fly ash as the main raw material, by addding gangue powder or clay, batching, molding, drying and firing. This can help make full use of industrial waste and save fuel.

 

Fire clay brick from China contains more than 40% Al2O3 and 2.0-2.5% Fe2O3. There are 65-85% clinker and 35-15% in the ingredients. The crushed bond clay and finely ground clinker are mixed and then formulated with clinker particles into semi-dry mud. The mud is then molded under high pressure and fired at 1400℃. 

 

Fire clay brick is weakly acidic at high temperature and has poor corrosion resistance to alkali slags, but with the increase of Al2O3 content, its corrosion resistance is increased. it has better thermal stabiltiy than silica brick and magnesia brick. 

 

After dried and vacuum impregnated with phosphoric acid, fire clay brick can be used in the the upper lining of the blast furnace.